Bio

Academic Appointments


Honors & Awards


  • Distinguished Clinical Scientist Award, Doris Duke Charitable Trust (2000-2005)

Research & Scholarship

Current Research and Scholarly Interests


Treatment and evaluation of HIV infection

Clinical Trials


  • Consent for Use of Stored Patient Specimens for Future Testing Recruiting

    The purpose of this study is to obtain informed consent to use stored human biological materials (HBM) (e.g., blood and other tissues) for future studies that may include genetic testing.

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  • Long-Term Data Collection From Participants in Adult AIDS Clinical Trials Not Recruiting

    The purpose of this study is to determine what combinations of anti-HIV drugs work best in patients treated over several years. The study will also assess the occurrence of side effects and opportunistic infections in patients with low viral loads compared to those with higher viral loads.

    Stanford is currently not accepting patients for this trial. For more information, please contact Debbie Slamowitz, 650-723-2804.

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Teaching

2019-20 Courses


Stanford Advisees


  • Scholarly Concentration Director
    Clare Cameron

Publications

All Publications


  • Community-based self-collected human papillomavirus screening in rural Zimbabwe. BMC public health Fitzpatrick, M. B., El-Khatib, Z., Katzenstein, D., Pinsky, B. A., Chirenje, Z. M., McCarty, K. 2019; 19 (Suppl 1): 603

    Abstract

    BACKGROUND: In low- and middle-income countries (LMIC), women have limited access to and uptake of cervical cancer screening. Delayed diagnosis leads to poorer outcomes and early mortality, and continues to impede cancer control disproportionately in LMIC. Integrating self-collected, community-based screening for High Risk-Human Papilloma Virus (HR-HPV) into existent HIV programs is a potential screening method to identify women at high risk for developing high-risk cervical lesions.METHODS: We implemented community-based cross-sectional study on self-collection HR-HPV screening in conjunction with existing community outreach models for the distribution of antiretroviral therapy (ART) and the World Health Organization Expanded Program on Immunization (EPI) outreach in villages in rural Zimbabwe from January 2017 through May 2017.RESULTS: Overall, there was an 82% response rate: 70% of respondents participated in self-collection and 12% were ineligible for the study (inclusion criteria: age 30-65, not pregnant, with an intact uterus). Women recruited in the first 2-3months of the study had more opportunities to participate and therefore significantly higher participation: 81% participation (additional 11% ineligible), while those with fewer opportunities also had lower participation: 63% (additional 13% ineligible) (p<0.001). Some village outreach centers (N=5/12) had greater than 89% participation.CONCLUSIONS: Integration of HR-HPV screening into existing community outreach models for HIV and immunizations could facilitate population-based screening to scale cancer control and prevention programs in sub-Saharan Africa. Community/village health workers (CHW/VHW) and village outreach programs offer a potential option for cervical cancer screening programs to move towards improving access of sexual and reproductive health resources for women at highest risk.

    View details for DOI 10.1186/s12889-019-6810-5

    View details for PubMedID 31138174

  • hrHPV prevalence and type distribution in rural Zimbabwe: A community-based self-collection study using near-point-of-care GeneXpert HPV testing INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES Fitzpatrick, M. B., Mandishora, R., Katzenstein, D. A., McCarty, K., Weber, J., Sahoo, M. K., Manasa, J., Chirenje, Z., Pinsky, B. A. 2019; 82: 21?29
  • Persistence of Human Immunodeficiency Virus-1 Drug Resistance Mutations in Proviral Deoxyribonucleic Acid After Virologic Failure of Efavirenz-Containing Antiretroviral Regimens OPEN FORUM INFECTIOUS DISEASES De La Cruz, J., Vardhanbhuti, S., Sahoo, M. K., Rovner, R., Bosch, R. J., Manasa, J., Katzenstein, D. A., Pinsky, B. A. 2019; 6 (3)
  • Persistence of Human Immunodeficiency Virus-1 Drug Resistance Mutations in Proviral Deoxyribonucleic Acid After Virologic Failure of Efavirenz-Containing Antiretroviral Regimens. Open forum infectious diseases De La Cruz, J., Vardhanbhuti, S., Sahoo, M. K., Rovner, R., Bosch, R. J., Manasa, J., Katzenstein, D. A., Pinsky, B. A. 2019; 6 (3): ofz034

    Abstract

    Background: Efavirenz (EFV)-based regimens select broad drug resistance to nonnucleoside reverse-transcriptase inhibitors (NNRTIs), limiting the effectiveness of EFV and other NNRTIs. The duration, persistence, and decay of drug resistance mutations (DRMs) in the proviral reservoir is not well defined.Methods: Participants with virologic failure of EFV-based regimens and drug-resistant viremia with the K103N mutation in plasma ribonucleic acid (RNA) were identified from AIDS Clinical Trials Group (ACTG) studies A364 and A5095. These individuals received a second-line, boosted protease inhibitor-based regimen with suppression of viremia for up to10 years during long-term follow-up (median = 3.6 years; interquartile range, 2.1-6.9 years). Proviral deoxyribonucleic acid (DNA) from cryopreserved peripheral blood mononuclear cells was sequenced to identify the persistence of DRM.Results: Twenty-eight participants from ACTG 364 and ACTG 5095 were evaluated. Sanger sequencing of proviral DNA detected K103N as well as additional reverse-transcriptase inhibitor (RTI) mutations. Ultradeep sequencing confirmed persistence of K103N in 71% of participants with minimal decay over time. In an adjusted model including years since suppression, persistent proviral K103N was 2.6 times more likely (95% confidence interval, 1.0-6.4) per log10 higher human immunodeficiency virus RNA at EFV failure.Conclusions: Persistence of RTI mutations in proviral DNA after virologic failure has implications for the effectiveness of future drug regimens and the recycling of RTI drugs.

    View details for PubMedID 30863788

  • Trends in Pretreatment HIV-1 Drug Resistance in Antiretroviral Therapy-naive Adults in South Africa, 2000-2016: A Pooled Sequence Analysis. EClinicalMedicine Chimukangara, B., Lessells, R. J., Rhee, S., Giandhari, J., Kharsany, A. B., Naidoo, K., Lewis, L., Cawood, C., Khanyile, D., Ayalew, K. A., Diallo, K., Samuel, R., Hunt, G., Vandormael, A., Stray-Pedersen, B., Gordon, M., Makadzange, T., Kiepiela, P., Ramjee, G., Ledwaba, J., Kalimashe, M., Morris, L., Parikh, U. M., Mellors, J. W., Shafer, R. W., Katzenstein, D., Moodley, P., Gupta, R. K., Pillay, D., Abdool Karim, S. S., de Oliveira, T. 2019; 9: 26?34

    Abstract

    Background: South Africa has the largest public antiretroviral therapy (ART) programme in the world. We assessed temporal trends in pretreatment HIV-1 drug resistance (PDR) in ART-naive adults from South Africa.Methods: We included datasets from studies conducted between 2000 and 2016, with HIV-1 pol sequences from more than ten ART-naive adults. We analysed sequences for the presence of 101 drug resistance mutations. We pooled sequences by sampling year and performed a sequence-level analysis using a generalized linear mixed model, including the dataset as a random effect.Findings: We identified 38 datasets, and retrieved 6880 HIV-1 pol sequences for analysis. The pooled annual prevalence of PDR remained below 5% until 2009, then increased to a peak of 119% (95% confidence interval (CI) 92-150) in 2015. The pooled annual prevalence of non-nucleoside reverse-transcriptase inhibitor (NNRTI) PDR remained below 5% until 2011, then increased to 10.0% (95% CI 8.4-11.8) by 2014. Between 2000 and 2016, there was a 1.18-fold (95% CI 1.13-1.23) annual increase in NNRTI PDR (p?

    View details for DOI 10.1016/j.eclinm.2019.03.006

    View details for PubMedID 31143879

  • hrHPV Prevalence and Type Distribution in Rural Zimbabwe: A Community-Based Self-Collection Study using Near-Point-of-Care GeneXpert HPV testing. International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases Fitzpatrick, M. B., Dube Mandishora, R. S., Katzenstein, D. A., McCarty, K., Weber, J., Sahoo, M. K., Manasa, J., Chirenje, Z. M., Pinsky, B. A. 2019

    Abstract

    OBJECTIVES: High-risk human papilloma viruses (hrHPV) are the causative agents of cervical cancer, the leading cause of cancer deaths among Zimbabwean women. The objective of this study was to describe the hrHPV types found in Zimbabwe for consideration in cervical cancer screening and vaccination efforts.DESIGN AND METHODS: To determine hrHPV prevalence and type distribution in Zimbabwe we implemented a community-based cross-sectional study of self-collected cervicovaginal samples with hrHPV screening using near-point-of-care Cepheid GeneXpert HPV.RESULTS: The hrHPV prevalence was 17% (112/643); 33% (41/123) vs. 14% (71/520) among HIV-1-positive and -negative participants, respectively (p=2.3E-07). Typing via Xpert HPV showed very good overall agreement (77.2%, kappa=0.698) with the Seegene Anyplex II HPV HR Detection kit. The most common types were HPV16, HPV18, HPV35, HPV52, HPV58, HPV68, HPV18, and HPV51, each of which appeared in 14-20% of infections. 37% (28/76) of women with positive cytology results (ASCUS+) had a type not included in the basic vaccine and 25% (19/76) had a type not currently in the nine-valent vaccine.CONCLUSIONS: hrHPV type distribution includes less common high-risk types in rural Zimbabwe. The distribution and carcinogenicity of hrHPV type distribution should be considered during screening assay design, program development, as well as vaccine distribution and design.

    View details for PubMedID 30807869

  • Patterns of detectable viraemia among children and adults with HIV infection taking antiretroviral therapy in Zimbabwe INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES Sovershaeva, E., Shamu, T., Wilsgaard, T., Bandason, T., Flaegstad, T., Katzenstein, D., Ferrand, R. A., Odland, J. 2019; 78: 65?71
  • Combining Phylogenetic and Network Approaches to Identify HIV-1 Transmission Links in San Mateo County, California FRONTIERS IN MICROBIOLOGY Dalai, S. C., Junqueira, D., Wilkinson, E., Mehra, R., Pond, S., Levy, V., Israelski, D., de Oliveira, T., Katzenstein, D. 2018; 9
  • Patterns of detectable viraemia among children and adults with HIV infection taking antiretroviral therapy in Zimbabwe. International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases Sovershaeva, E., Shamu, T., Wilsgaard, T., Bandason, T., Flagstad, T., Katzenstein, D., Ferrand, R. A., Odland, J. 2018

    Abstract

    OBJECTIVE: To investigate the incidence and predictors of viraemia among individuals on antiretroviral therapy (ART) in Harare.METHODS: Children (0-19 years) and adults (>19years) starting ART between 2013 and 2015 were followed for a median of 2.8 and 2.7 years respectively. The incidence rates of virological failure (VF), low level viraemia (LLV) and viral blips were assessed and the predictors of viraemia were determined using logistic and parametric survival regression.RESULTS: Of the 630 individuals that initiated ART, 19.7% of children and 5.6% of adults did not achieve viral suppression by 12 months. Younger age and CD4 count ?200 cells/mm3 at baseline were associated with not being virally suppressed at 12 months in adults. Among those who achieved viral suppression during the follow up period, the incidence of VF was higher in children (4.0/100 person years (PYs) vs 0.4/100 PYs in adults, p<0.001), as was the incidence of LLV (1.9/100 PYs vs 0.3/100 PYs in adults, p=0.03). The incidence rate of blips was 10.9 and 4.0 per 100 PYs in children and adults, respectively.CONCLUSIONS: Children are less likely to reach viral suppression and are at higher risk of viraemia while on ART than adults. The significance of LLV and blips needs further study.

    View details for PubMedID 30391420

  • HIV-1 Drug Resistance and Third-Line Therapy Outcomes in Patients Failing Second-Line Therapy in Zimbabwe OPEN FORUM INFECTIOUS DISEASES Chimbetete, C., Katzenstein, D., Shamu, T., Spoerri, A., Estill, J., Egger, M., Keiser, O. 2018; 5 (2): ofy005

    Abstract

    To analyze the patterns and risk factors of HIV drug resistance mutations among patients failing second-line treatment and to describe early treatment responses to recommended third-line antiretroviral therapy (ART) in a national referral HIV clinic in Zimbabwe.Patients on boosted protease inhibitor (PI) regimens for more than 6 months with treatment failure confirmed by 2 viral load (VL) tests >1000 copies/mL were genotyped, and susceptibility to available antiretroviral drugs was estimated by the Stanford HIVdb program. Risk factors for major PI resistance were assessed by logistic regression. Third-line treatment was provided as Darunavir/r, Raltegravir, or Dolutegravir and Zidovudine, Abacavir Lamivudine, or Tenofovir.Genotypes were performed on 86 patients who had good adherence to treatment. The median duration of first- and second-line ART was 3.8 years (interquartile range [IQR], 2.3-5.1) and 2.6 years (IQR, 1.6-4.9), respectively. The median HIV viral load and CD4 cell count were 65 210 copies/mL (IQR, 8728-208 920 copies/mL) and 201 cells/mm3 (IQR, 49-333 cells/mm3). Major PI resistance-associated mutations (RAMs) were demonstrated in 44 (51%) non-nucleoside reverse transcriptase inhibitor RAMs in 72 patients (83%) and nucleoside reverse transcriptase inhibitors RAMs in 62 patients (72%). PI resistance was associated with age >24 years (P = .003) and CD4 cell count <200 cells/mm3 (P = .007). In multivariable analysis, only age >24 years was significantly associated (adjusted odds ratio, 4.75; 95% confidence interval, 1.69-13.38; P = .003) with major PI mutations. Third-line DRV/r- and InSTI-based therapy achieved virologic suppression in 29/36 patients (81%) after 6 months.The prevelance of PI mutations was high. Adolescents and young adults had a lower risk of acquiring major PI resistance mutations, possibly due to poor adherence to ART. Third-line treatment with a regimen of Darunavir/r, Raltegravir/Dolutegravir, and optimized nucleoside reverse transcriptase inhibitors was effective.

    View details for DOI 10.1093/ofid/ofy005

    View details for Web of Science ID 000427179600008

    View details for PubMedID 29435471

    View details for PubMedCentralID PMC5801603

  • Combining Phylogenetic and Network Approaches to Identify HIV-1 Transmission Links in San Mateo County, California. Frontiers in microbiology Dalai, S. C., Junqueira, D. M., Wilkinson, E., Mehra, R., Kosakovsky Pond, S. L., Levy, V., Israelski, D., de Oliveira, T., Katzenstein, D. 2018; 9: 2799

    Abstract

    The HIV epidemic in San Mateo County is sustained by multiple overlapping risk groups and is an important hub for HIV transmission in northern California. Limited access to care has led historically to delayed clinical presentation, higher rates of opportunistic infections, and an increased prevalence of antiretroviral drug resistance. The virologic and clinical consequences of treatment within these multiple ethnic and behavioral groups are poorly understood, highlighting the need for efficient surveillance strategies that are able to elucidate transmission networks and drug resistance patterns. We obtained sequence data from a group of 316 HIV-positive individuals in the San Mateo AIDS Program over a 14-year period and integrated epidemiologic, phylogenetic, and network approaches to characterize transmission clusters, risk factors and drug resistance. Drug resistance mutations were identified using the Stanford HIV Drug Resistance Database. A maximum likelihood tree was inferred in RAxML and subjected to clustering analysis in Cluster Picker. Network analysis using pairwise genetic distances was performed in HIV-TRACE. Participants were primarily male (60%), white Hispanics and non-Hispanics (32%) and African American (20.6%). The most frequent behavior risk factor was male-male sex (33.5%), followed by heterosexual (23.4%) and injection drug use (9.5%). Nearly all sequences were subtype B (96%) with subtypes A, C, and CRF01_AE also observed. Sequences from 65% of participants had at least one drug resistance mutation. Clustered transmissions included a higher number of women when compared to non-clustered individuals and were more likely to include heterosexual or people who inject drugs (PWID). Detailed analysis of the largest network (N = 47) suggested that PWID played a central role in overall transmission of HIV-1 as well as bridging men who have sex with men (MSM) transmission with heterosexual/PWID among primarily African American men. Combined phylogenetic and network analysis of HIV sequence data identified several overlapping risk factors in the epidemic, including MSM, heterosexual and PWID transmission with a disproportionate impact on African Americans and a high prevalence of drug resistance.

    View details for PubMedID 30574123

  • Community Based Antiretroviral Treatment in Rural Zimbabwe AIDS RESEARCH AND HUMAN RETROVIRUSES Chimukangara, B., Manasa, J., Mitchell, R., Nyabadza, G., Katzenstein, D., Masimirembwa, C. 2017; 33 (12): 1185?91

    Abstract

    Treatment of HIV has reduced HIV/AIDS-related mortality. Sustaining >90% virologic suppression in sub-Saharan Africa requires decentralized care and prevention services to rural communities. In Zimbabwe, the number of people receiving antiretroviral treatment (ART) has increased rapidly. However, access to treatment monitoring tools such as viral load and drug resistance testing is limited. We assessed virologic treatment outcomes among ART recipients in Nyamutora, a rural community receiving bimonthly ART and prevention services. We enrolled all ART recipients (143) at 6-monthly visits in the Nyamutora community in 2014 and 2015. Whole blood samples were collected in K-EDTA tubes, transported to Harare for CD4 counts and viral load testing, and genotype was obtained in participants with viral loads >1,000 copies/ml. Ages ranged from 2 to 75 years (median 43 years) with a median 42 months on ART at follow-up. Eight of 143 (6%) had viral loads >1,000 copies/ml at one of the 3 visits, 7 on first-line nevirapine (NVP)-based ART and 1 on second-line LPV/r-based ART. Seven participants had sequence data available, and five had drug resistance mutations, K65R, T69N, K101E, K103N, Y181C/I, M184V, and G190A. Virologic failure (p?=?.001) and drug resistance mutations (p?=?.01) on first-line NVP-based ART were associated with younger age by univariate exact logistic regression. The participants had high viral suppression (94%) despite less than optimal (NVP based) ART regimens without laboratory monitoring. Virologic failure and drug resistance were higher among children and adolescents. Effective ART delivery to the community achieved high rates of virologic suppression and minimal drug resistance.

    View details for PubMedID 28899102

  • Defining a cut-off for atazanavir in hair samples associated with virological failure among adolescents failing second-line antiretroviral treatment. Journal of acquired immune deficiency syndromes Chawana, T. D., Gandhi, M., Nathoo, K., Ngara, B., Louie, A., Horng, H., Katzenstein, D., Metcalfe, J., Brian Nhachi, C. F. 2017

    Abstract

    Adequate antiretroviral exposure is crucial for virological suppression. We assessed the relationship between atazanavir hair levels with self-reported adherence, virological outcomes, and the effect of a home-based adherence intervention in HIV-infected adolescents failing 2-line antiretroviral treatment in Zimbabwe.HIV-infected adolescents on atazanavir/ritonavir-based 2-line treatment for ?6 months with viral load (VL) >1,000 copies/ml were randomised to either standard care (control) or standard care plus modified directly administered antiretroviral therapy (mDAART) (intervention). Questionnaires were administered; VL and hair samples were collected at baseline and after 90 days in each group. Viral suppression was defined as <1,000 copies/ml after follow-up.Fifty adolescents (10-18 years) were enrolled; 23(46%) were randomized to intervention and 27(54%) to control. Atazanavir hair concentration <2.35ng/mg (lower inter-quartile range for those with virological suppression) defined a cut-off below which most participants experienced virological failure. Male sex (p=0.03), virological suppression at follow-up (p=0.013), greater reduction in VL (p=0.006) and change in average self-reported adherence over the previous month (p=0.031) were associated with adequate (>2.35ng/mg) hair concentrations. Participants with virological failure were more likely to have sub-optimal atazanavir hair concentrations (RR=7.2, 95% CI=1-51, p=0.049). There were no differences in atazanavir hair concentration between the arms after follow-up.A threshold of atazanavir concentrations in hair (2.35ng/mg), above which virological suppression was likely, was defined for adolescents failing 2 line atazanavir/ritonavir-based ART in Zimbabwe. Male sex and better self-reported adherence were associated with adequate atazanavir hair concentrations. Antiretroviral hair concentrations may serve as a useful clinical tool among adolescents.

    View details for DOI 10.1097/QAI.0000000000001452

    View details for PubMedID 28520618

  • HIV drug resistance testing among patients failing second line antiretroviral therapy. Comparison of in-house and commercial sequencing JOURNAL OF VIROLOGICAL METHODS Chimukangara, B., Varyani, B., Shamu, T., Mutsvangwa, J., Manasa, J., White, E., Chimbetete, C., Luethy, R., Katzenstein, D. 2017; 243: 151-157
  • A Simple Phosphate-Buffered-Saline-Based Extraction Method Improves Specificity of HIV Viral Load Monitoring Using Dried Blood Spots. Journal of clinical microbiology Makadzange, A. T., Boyd, F. K., Chimukangara, B., Masimirembwa, C., Katzenstein, D., Ndhlovu, C. E. 2017; 55 (7): 2172?79

    Abstract

    Although Roche COBAS Ampliprep/COBAS TaqMan (CAP/CTM) systems are widely used in sub-Saharan Africa for early infant diagnosis of HIV from dried blood spots (DBS), viral load monitoring with this system is not practical due to nonspecific extraction of both cell-free and cell-associated viral nucleic acids. A simplified DBS extraction technique for cell-free virus elution using phosphate-buffered saline (PBS) may provide an alternative analyte for lower-cost quantitative HIV virus load (VL) testing to monitor antiretroviral therapy (ART). We evaluated the CAP/CTM v2.0 assay in 272 paired plasma and DBS specimens using the cell-free virus elution method and determined the level of agreement, sensitivity, and specificity at thresholds of target not detected (TND), target below the limit of quantification (BLQ) (<20 copies/ml in plasma or <400 copies/ml in DBS), and VL of <1,000 copies/ml, and VL of <5,000 copies/ml. Reported plasma VL ranged from TND, or <20, to 5,781,592 copies/ml, and DBS VL ranged from TND, or <400, to 467,600 copies/ml. At <1000 copies/ml, agreement between DBS and plasma was 96.7% (kappa coefficient, 0.93; P < 0.0001). The mean difference between DBS and plasma VL values was -1.06 log10 copies/ml (95% confidence interval [CI], -1.17, -0.97; P < 0.0001). At a treatment failure threshold of >1,000 copies/ml, the sensitivities, specificities, positive predictive values (PPV), and negative predictive values (NPV) were 92.7%, 100%, 100%, and 94.3%, respectively. PBS elution of DBS offers a sensitive and specific method for monitoring plasma viremia among adults and children on ART at the WHO-recommended threshold of >1,000 copies/ml on the Roche CAP/CTM system.

    View details for PubMedID 28468852

    View details for PubMedCentralID PMC5483919

  • Evaluating an enhanced adherence intervention among HIV positive adolescents failing atazanavir/ritonavir-based second line antiretroviral treatment at a public health clinic. Journal of AIDS and HIV research (Online) Chawana, T. D., Katzenstein, D., Nathoo, K., Ngara, B., Nhachi, C. F. 2017; 9 (1): 17?30

    Abstract

    Sustaining virological suppression among HIV-infected adolescents is challenging. We evaluated a home-based adherence intervention and characterized self-reported adherence, virological response and drug resistance among adolescents failing atazanavir/ritonavir (ATV/r)-based 2nd line treatment.HIV-positive adolescents (10-18 years) on ATV/r-based 2nd line treatment with virological failure (viral load (VL) ?1 000 copies/ml) were randomized to either standard care (SC) or SC with addition of modified directly administered antiretroviral therapy (mDAART) for 90 days. VL was measured and questionnaires were administered at study entry and at 3 months. Genotyping was done for participants with continued failure. Primary outcome was suppression to VL < 1 000 copies/ml.Fifty adolescents aged 10-18 years on 2nd line treatment for >180 days were enrolled, 23(46%) were randomized to mDAART and 27(54%) to SC. Fifty-four percent were female; mean age was 15.8 years; mean baseline VL was 4.8(log10) copies/ml; 40% reported adherence <80% in previous 1 month at baseline; 40% suppressed (VL <1 000 copies/ml) after follow-up. mDAART resulted in significantly increased self-reported adherence (RR= 0.1; 95% CI=0.02-0.8, p=0.023); closely following dosing schedule (RR= 4.8; 95% CI=1.6-13.8, p=0.004); VL decrease (p=0.031) and modest increase in virological suppression to <1 000 copies/ml (p=0.105). Genotyping in 28/30 participants with continued virological failure demonstrated high level atazanavir resistance (I50L, N88S and I84V) in 6(21%); 3(11%) of whom also had high level resistance to lopinavir and darunavir (V32I, I50L, I54V, 147V and V82A).The mDAART intervention modestly improved virological suppression among adolescents with ATV/r-based 2nd line treatment failure, significantly increased self-reported adherence and decreased viral load. High level ATV/r resistance was demonstrated.Targeting mDAART to adolescents who are virologically failing PI-based 2nd line treatment decreases viral load and increases self-reported adherence. Early drug-resistance testing could reduce morbidity and mortality.

    View details for DOI 10.5897/JAHR2016.0406

    View details for PubMedID 31649827

    View details for PubMedCentralID PMC6812532

  • Evolution of gag and gp41 in Patients Receiving Ritonavir-Boosted Protease Inhibitors. Scientific reports Manasa, J., Varghese, V., Pond, S. L., Rhee, S. Y., Tzou, P. L., Fessel, W. J., Jang, K. S., White, E., Rgnvaldsson, T., Katzenstein, D. A., Shafer, R. W. 2017; 7 (1): 11559

    Abstract

    Several groups have proposed that genotypic determinants in gag and the gp41 cytoplasmic domain (gp41-CD) reduce protease inhibitor (PI) susceptibility without PI-resistance mutations in protease. However, no gag and gp41-CD mutations definitively responsible for reduced PI susceptibility have been identified in individuals with virological failure (VF) while receiving a boosted PI (PI/r)-containing regimen. To identify gag and gp41 mutations under selective PI pressure, we sequenced gag and/or gp41 in 61 individuals with VF on a PI/r (n?=?40) or NNRTI (n?=?20) containing regimen. We quantified nonsynonymous and synonymous changes in both genes and identified sites exhibiting signal for directional or diversifying selection. We also used published gag and gp41 polymorphism data to highlight mutations displaying a high selection index, defined as changing from a conserved to an uncommon amino acid. Many amino acid mutations developed in gag and in gp41-CD in both the PI- and NNRTI-treated groups. However, in neither gene, were there discernable differences between the two groups in overall numbers of mutations, mutations displaying evidence of diversifying or directional selection, or mutations with a high selection index. If gag and/or gp41 encode PI-resistance mutations, they may not be confined to consistent mutations at a few sites.

    View details for PubMedID 28912582

  • Collaborative update of a rule-based expert system for HIV-1 genotypic resistance test interpretation. PloS one Paredes, R., Tzou, P. L., van Zyl, G., Barrow, G., Camacho, R., Carmona, S., Grant, P. M., Gupta, R. K., Hamers, R. L., Harrigan, P. R., Jordan, M. R., Kantor, R., Katzenstein, D. A., Kuritzkes, D. R., Maldarelli, F., Otelea, D., Wallis, C. L., Schapiro, J. M., Shafer, R. W. 2017; 12 (7): e0181357

    Abstract

    HIV-1 genotypic resistance test (GRT) interpretation systems (IS) require updates as new studies on HIV-1 drug resistance are published and as treatment guidelines evolve.An expert panel was created to provide recommendations for the update of the Stanford HIV Drug Resistance Database (HIVDB) GRT-IS. The panel was polled on the ARVs to be included in a GRT report, and the drug-resistance interpretations associated with 160 drug-resistance mutation (DRM) pattern-ARV combinations. The DRM pattern-ARV combinations included 52 nucleoside RT inhibitor (NRTI) DRM pattern-ARV combinations (13 patterns x 4 NRTIs), 27 nonnucleoside RT inhibitor (NNRTI) DRM pattern-ARV combinations (9 patterns x 3 NNRTIs), 39 protease inhibitor (PI) DRM pattern-ARV combinations (13 patterns x 3 PIs) and 42 integrase strand transfer inhibitor (INSTI) DRM pattern-ARV combinations (14 patterns x 3 INSTIs).There was universal agreement that a GRT report should include the NRTIs lamivudine, abacavir, zidovudine, emtricitabine, and tenofovir disoproxil fumarate; the NNRTIs efavirenz, etravirine, nevirapine, and rilpivirine; the PIs atazanavir/r, darunavir/r, and lopinavir/r (with "/r" indicating pharmacological boosting with ritonavir or cobicistat); and the INSTIs dolutegravir, elvitegravir, and raltegravir. There was a range of opinion as to whether the NRTIs stavudine and didanosine and the PIs nelfinavir, indinavir/r, saquinavir/r, fosamprenavir/r, and tipranavir/r should be included. The expert panel members provided highly concordant DRM pattern-ARV interpretations with only 6% of NRTI, 6% of NNRTI, 5% of PI, and 3% of INSTI individual expert interpretations differing from the expert panel median by more than one resistance level. The expert panel median differed from the HIVDB 7.0 GRT-IS for 20 (12.5%) of the 160 DRM pattern-ARV combinations including 12 NRTI, two NNRTI, and six INSTI pattern-ARV combinations. Eighteen of these differences were updated in HIVDB 8.1 GRT-IS to reflect the expert panel median. Additionally, HIVDB users are now provided with the option to exclude those ARVs not considered to be universally required.The HIVDB GRT-IS was updated through a collaborative process to reflect changes in HIV drug resistance knowledge, treatment guidelines, and expert opinion. Such a process broadens consensus among experts and identifies areas requiring further study.

    View details for PubMedID 28753637

  • HIV drug resistance testing among patients failing second line antiretroviral therapy. Comparison of in-house and commercial sequencing. Journal of virological methods Chimukangara, B., Varyani, B., Shamu, T., Mutsvangwa, J., Manasa, J., White, E., Chimbetete, C., Luethy, R., Katzenstein, D. 2017; 243: 151?57

    Abstract

    HIV genotyping is often unavailable in low and middle-income countries due to infrastructure requirements and cost. We compared genotype resistance testing in patients with virologic failure, by amplification of HIV pol gene, followed by "in-house" sequencing and commercial sequencing.Remnant plasma samples from adults and children failing second-line ART were amplified and sequenced using in-house and commercial di-deoxysequencing, and analyzed in Harare, Zimbabwe and at Stanford, U.S.A, respectively. HIV drug resistance mutations were determined using the Stanford HIV drug resistance database.Twenty-six of 28 samples were amplified and 25 were successfully genotyped. Comparison of average percent nucleotide and amino acid identities between 23 pairs sequenced in both laboratories were 99.51 (0.56) and 99.11 (0.95), respectively. All pairs clustered together in phylogenetic analysis. Sequencing analysis identified 6/23 pairs with mutation discordances resulting in differences in phenotype, but these did not impact future regimens.The results demonstrate our ability to produce good quality drug resistance data in-house. Despite discordant mutations in some sequence pairs, the phenotypic predictions were not clinically significant.

    View details for PubMedID 27894862

    View details for PubMedCentralID PMC5393912

  • Evaluation of the Aptima HIV-1 Quant Dx Assay Using Plasma and Dried Blood Spots. Journal of clinical microbiology Sahoo, M. K., Varghese, V., White, E., Winslow, M., Katzenstein, D. A., Shafer, R. W., Pinsky, B. A. 2016; 54 (10): 2597-2601

    Abstract

    HIV-1 RNA quantitation in plasma, or virus load testing, is the primary method by which the response to antiretroviral therapy is monitored. Here we describe evaluation of the Aptima HIV-1 Quant Dx assay (Aptima) performed on the automated Panther system. The clinical performance of Aptima was compared to that of the Cobas AmpliPrep/Cobas TaqMan HIV-1 Test v2.0 (CAP/CTM) using 162 EDTA plasma samples collected from patients undergoing HIV-1 monitoring. Overall agreement was 84.0% (136/162), with a kappa statistic of 0.723 (standard error, 0.047; 95% confidence interval [CI], 0.630 to 0.815), indicating substantial agreement. Using the 86 clinical samples quantifiable by both methods, Passing-Bablok regression revealed a regression line of Y = (1.069 X) - 0.346 (95% CI of the slope [1.003 to 1.139] and intercept [-0.666 to -0.074]), and Bland-Altman analysis demonstrated a mean difference (Aptima-CAP/CTM) of -0.075 log10 copies/ml (95% limits of agreement of -0.624 to 0.475), consistent with negative bias. Comparison of Aptima results for paired dried blood spot (DBS) and plasma specimens archived from participants in the Peninsula AIDS Research Cohort Study (PARC) demonstrated an overall agreement of 94.7% (90/95) when 1,000 copies/ml was used as the threshold. In conclusion, the Aptima HIV-1 Quant Dx assay provides a suitable alternative for HIV-1 monitoring in plasma and DBS.

    View details for DOI 10.1128/JCM.01569-16

    View details for PubMedID 27535684

    View details for PubMedCentralID PMC5035416

  • Transmitted HIV Drug Resistance Is High and Longstanding in Metropolitan Washington, DC CLINICAL INFECTIOUS DISEASES Kassaye, S. G., Grossman, Z., Balamane, M., Johnston-White, B., Liu, C., Kumar, P., Young, M., Sneller, M. C., Sereti, I., Dewar, R., Rehm, C., Meyer, W., Shafer, R., Katzenstein, D., Maldarelli, F. 2016; 65 (6): 836-843

    Abstract

    ?Washington, D.C., has 2.5% HIV prevalence, 3.9% among African Americans. Antiretrovirals are the cornerstone for treatment and prevention. Monitoring changes in transmitted drug resistance (TDR) is critical for effective HIV care.?HIV genotype data for individuals enrolled in research studies in metropolitan Washington, D.C., were used to identify TDR using the World Health Organization mutation list[1]. HIV phylogenies were reconstructed using maximum likelihood and Bayesian methods. HIV transmission clusters were supported by 1000 bootstrap values >0.70 and posterior probability >0.95 of having a common ancestor.?Among 710 individuals enrolled in 1994-2013, the median age was 38.6 years, 46.2% were female, and 53.3% were African-American. TDR was 22.5% among 566 treatment nave individuals; 15.8% had NRTI resistance, 9.8% had NNRTI resistance, and 4.2% had PI resistance. Single class TDR was 10.0%, 5.1%, 1.6% to NRTIs, NNRTIs, and PIs. Dual TDR to PI and NRTI was seen in 1.6%, NRTI and NNRTI in 3.4%, and triple class TDR in 0.9%. The most common NRTI-associated TDR mutations were L215Y/F/D/S (7.0%), D67N/G/E (5.0%), M41L (4.6%), K70R (4.5%), and M184V (3.9%); NNRTI-associated mutation was K103N/S (7.1%); and PI-associated mutation was L90M (2.0%). TDR frequency decreased from 1994-2006 (27.1%) to 2007-2013 (19.4%) (p=0.02). Only 6/79 (7.6%) individuals within transmission clusters had evidence of TDR.We identified high prevalence of TDR among HIV-infected individuals in metropolitan Washington, D.C., regardless of gender. Active surveillance for TDR is needed to guide antiretroviral usage and analyses of risk group contributions to HIV transmission and resistance.

    View details for DOI 10.1093/cid/ciw382

    View details for Web of Science ID 000383857500022

  • Transmitted HIV Drug Resistance Is High and Longstanding in Metropolitan Washington, DC. Clinical infectious diseases Kassaye, S. G., Grossman, Z., Balamane, M., Johnston-White, B., Liu, C., Kumar, P., Young, M., Sneller, M. C., Sereti, I., Dewar, R., Rehm, C., Meyer, W., Shafer, R., Katzenstein, D., Maldarelli, F. 2016; 63 (6): 836-843

    Abstract

    ?Washington, D.C., has 2.5% HIV prevalence, 3.9% among African Americans. Antiretrovirals are the cornerstone for treatment and prevention. Monitoring changes in transmitted drug resistance (TDR) is critical for effective HIV care.?HIV genotype data for individuals enrolled in research studies in metropolitan Washington, D.C., were used to identify TDR using the World Health Organization mutation list[1]. HIV phylogenies were reconstructed using maximum likelihood and Bayesian methods. HIV transmission clusters were supported by 1000 bootstrap values >0.70 and posterior probability >0.95 of having a common ancestor.?Among 710 individuals enrolled in 1994-2013, the median age was 38.6 years, 46.2% were female, and 53.3% were African-American. TDR was 22.5% among 566 treatment nave individuals; 15.8% had NRTI resistance, 9.8% had NNRTI resistance, and 4.2% had PI resistance. Single class TDR was 10.0%, 5.1%, 1.6% to NRTIs, NNRTIs, and PIs. Dual TDR to PI and NRTI was seen in 1.6%, NRTI and NNRTI in 3.4%, and triple class TDR in 0.9%. The most common NRTI-associated TDR mutations were L215Y/F/D/S (7.0%), D67N/G/E (5.0%), M41L (4.6%), K70R (4.5%), and M184V (3.9%); NNRTI-associated mutation was K103N/S (7.1%); and PI-associated mutation was L90M (2.0%). TDR frequency decreased from 1994-2006 (27.1%) to 2007-2013 (19.4%) (p=0.02). Only 6/79 (7.6%) individuals within transmission clusters had evidence of TDR.We identified high prevalence of TDR among HIV-infected individuals in metropolitan Washington, D.C., regardless of gender. Active surveillance for TDR is needed to guide antiretroviral usage and analyses of risk group contributions to HIV transmission and resistance.

    View details for DOI 10.1093/cid/ciw382

    View details for PubMedID 27307507

  • Editorial Commentary: Scaling Up Antiretroviral Therapy in Africa: Are We There Yet? Clinical infectious diseases Manasa, J., Katzenstein, D. 2016; 62 (4): 519-520

    View details for DOI 10.1093/cid/civ931

    View details for PubMedID 26561533

  • Phenotype, Genotype, and Drug Resistance in Subtype C HIV-1 Infection JOURNAL OF INFECTIOUS DISEASES Derache, A., Wallis, C. L., Vardhanabhuti, S., Bartlett, J., Kumarasamy, N., Katzenstein, D. 2016; 213 (2): 250-256

    Abstract

    Virologic failure in subtype C is characterized by high resistance to first-line antiretroviral (ARV) drugs, including efavirenz, nevirapine, and lamivudine, with nucleoside resistance including type 2 thymidine analog mutations, K65R, a T69del, and M184V. However, genotypic algorithms predicting resistance are mainly based on subtype B viruses and may under- or overestimate drug resistance in non-B subtypes. To explore potential treatment strategies after first-line failure, we compared genotypic and phenotypic susceptibility of subtype C human immunodeficiency virus 1 (HIV-1) following first-line ARV failure.AIDS Clinical Trials Group 5230 evaluated patients failing an initial nonnucleoside reverse-transcriptase inhibitor (NNRTI) regimen in Africa and Asia, comparing the genotypic drug resistance and phenotypic profile from the PhenoSense (Monogram). Site-directed mutagenesis studies of K65R and T69del assessed the phenotypic impact of these mutations.Genotypic algorithms overestimated resistance to etravirine and rilpivirine, misclassifying 28% and 32%, respectively. Despite K65R with the T69del in 9 samples, tenofovir retained activity in >60%. Reversion of the K65R increased susceptibility to tenofovir and other nucleosides, while reversion of the T69del showed increased resistance to zidovudine, with little impact on other NRTI.Although genotype and phenotype were largely concordant for first-line drugs, estimates of genotypic resistance to etravirine and rilpivirine may misclassify subtype C isolates compared to phenotype.

    View details for DOI 10.1093/infdis/jiv383

    View details for Web of Science ID 000371237900012

    View details for PubMedID 26175454

    View details for PubMedCentralID PMC4690149

  • Human Immunodeficiency Virus-1 Sequence Changes and Drug Resistance Mutation Among Virologic Failures of Lopinavir/Ritonavir Monotherapy: AIDS Clinical Trials Group Protocol A5230. Open forum infectious diseases Vardhanabhuti, S., Katzenstein, D., Bartlett, J., Kumarasamy, N., Wallis, C. L. 2016; 3 (3): ofw154

    Abstract

    Background. ?The mechanism of virologic failure (VF) of lopinavir/ritonavir (LPV/r) monotherapy is not well understood. We assessed sequence changes in human immunodeficiency virus-1 reverse-transcriptase (RT) and protease (PR) regions. Methods. ?Human immunodeficiency virus-1 pol sequences from 34 participants who failed second-line LPV/r monotherapy were obtained at study entry (SE) and VF. Sequence changes were evaluated using phylogenetic analysis and hamming distance. Results. ?Human immunodeficiency virus-1 sequence change was higher over drug resistance mutation (DRM) sites (median genetic distance, 2.2%; Q1 to Q3, 2.1%-2.5%) from SE to VF compared with non-DRM sites (median genetic distance, 1.3%; Q1 to Q3, 1.0%-1.4%; P < .0001). Evolution over DRM sites was mainly driven by changes in the RT (median genetic distance, 2.7%; Q1 to Q3, 2.2%-3.2%) compared with PR (median genetic distance, 1.1%; Q1 to Q3, 0.0%-1.1%; P < .0001). Most RT DRMs present at SE were lost at VF. At VF, 19 (56%) and 26 (76%) were susceptible to efavirenz/nevirapine and etravirine (ETV)/rilpivirine (RPV), respectively, compared with 1 (3%) and 12 (35%) at SE. Participants who retained nonnucleoside reverse-transcriptase inhibitor (NNRTI) DRMs and those without evolution of LPV/r DRMs had significantly shorter time to VF. Conclusions. ?The selection of LPV/r DRMs in participants with longer time to VF suggests better adherence and more selective pressure. Fading NNRTI mutations and an increase in genotypic susceptibility to ETV and RPV could allow for the reuse of NNRTI. Further studies are warranted to understand mechanisms of PR failure.

    View details for PubMedID 27704010

    View details for PubMedCentralID PMC5047431

  • The cryptococcal antigen lateral flow assay: A point-of-care diagnostic at an opportune time CRITICAL REVIEWS IN MICROBIOLOGY Tang, M. W., Clemons, K. V., Katzenstein, D. A., Stevens, D. A. 2016; 42 (4): 634-642

    Abstract

    Cryptococcal meningitis is a devastating HIV-related opportunistic infection, affecting nearly 1 million individuals and causing over 500?000 deaths each year. The burden of disease is greatest in sub-Saharan Africa and Southeast Asia, where cryptococcal disease is the most common cause of meningitis. Rapid, accurate and affordable diagnosis of cryptococcal disease has been lacking in many of the most heavily affected areas. Here, we review a point-of-care assay for cryptococcal disease, the dipstick-formatted cryptococcal antigen lateral flow assay (LFA) (IMMY, Norman, OK). In comparison to culture, the assay is 99.5% sensitive and 98% specific. In comparison to other commercially available tests for cryptococcal antigen, the LFA has equal or superior sensitivity and specificity in CSF, plasma and serum samples. We discuss potential applications for the use of the assay in resource-limited settings, including what is likely to be an important role of the LFA in screening for early cryptococcal infection before clinical disease and in evaluating pre-emptive treatment.

    View details for DOI 10.3109/1040841X.2014.982509

    View details for Web of Science ID 000380186300009

    View details for PubMedID 25612826

  • Global Comparison of Drug Resistance Mutations After First-Line Antiretroviral Therapy Across Human Immunodeficiency Virus-1 Subtypes. Open forum infectious diseases Huang, A., Hogan, J. W., Luo, X., DeLong, A., Saravanan, S., Wu, Y., Sirivichayakul, S., Kumarasamy, N., Zhang, F., Phanuphak, P., Diero, L., Buziba, N., Istrail, S., Katzenstein, D. A., Kantor, R. 2016; 3 (2): ofv158

    Abstract

    Background. ?Human immunodeficiency virus (HIV)-1 drug resistance mutations (DRMs) often accompany treatment failure. Although subtype differences are widely studied, DRM comparisons between subtypes either focus on specific geographic regions or include populations with heterogeneous treatments. Methods. ?We characterized DRM patterns following first-line failure and their impact on future treatment in a global, multi-subtype reverse-transcriptase sequence dataset. We developed a hierarchical modeling approach to address the high-dimensional challenge of modeling and comparing frequencies of multiple DRMs in varying first-line regimens, durations, and subtypes. Drug resistance mutation co-occurrence was characterized using a novel application of a statistical network model. Results. ?In 1425 sequences, 202 subtype B, 696 C, 44 G, 351 circulating recombinant forms (CRF)01_AE, 58 CRF02_AG, and 74 from other subtypes mutation frequencies were higher in subtypes C and CRF01_AE compared with B overall. Mutation frequency increased by 9%-20% at reverse transcriptase positions 41, 67, 70, 184, 215, and 219 in subtype C and CRF01_AE vs B. Subtype C and CRF01_AE exhibited higher predicted cross-resistance (+12%-18%) to future therapy options compared with subtype B. Topologies of subtype mutation networks were mostly similar. Conclusions. ?We find clear differences in DRM outcomes following first-line failure, suggesting subtype-specific ecological or biological factors that determine DRM patterns.

    View details for PubMedID 27419147

    View details for PubMedCentralID PMC4943563

  • HIV-1 Drug Resistance Mutations: Potential Applications for Point-of-Care Genotypic Resistance Testing PLOS ONE Rhee, S., Jordan, M. R., Raizes, E., Chua, A., Parkin, N., Kantor, R., van Zyl, G. U., Mukui, I., Hosseinipour, M. C., Frenkel, L. M., Ndembi, N., Hamers, R. L., de Wit, T. F., Wallis, C. L., Gupta, R. K., Fokam, J., Zeh, C., Schapiro, J. M., Carmona, S., Katzenstein, D., Tang, M., Aghokeng, A. F., de Oliveira, T., Wensing, A. M., Gallant, J. E., Wainberg, M. A., Richman, D. D., Fitzgibbon, J. E., Schito, M., Bertagnolio, S., Yang, C., Shafer, R. W. 2015; 10 (12)

    Abstract

    The increasing prevalence of acquired and transmitted HIV-1 drug resistance is an obstacle to successful antiretroviral therapy (ART) in the low- and middle-income countries (LMICs) hardest hit by the HIV-1 pandemic. Genotypic drug resistance testing could facilitate the choice of initial ART in areas with rising transmitted drug resistance (TDR) and enable care-providers to determine which individuals with virological failure (VF) on a first- or second-line ART regimen require a change in treatment. An inexpensive near point-of-care (POC) genotypic resistance test would be useful in settings where the resources, capacity, and infrastructure to perform standard genotypic drug resistance testing are limited. Such a test would be particularly useful in conjunction with the POC HIV-1 viral load tests that are currently being introduced in LMICs. A POC genotypic resistance test is likely to involve the use of allele-specific point mutation assays for detecting drug-resistance mutations (DRMs). This study proposes that two major nucleoside reverse transcriptase inhibitor (NRTI)-associated DRMs (M184V and K65R) and four major NNRTI-associated DRMs (K103N, Y181C, G190A, and V106M) would be the most useful for POC genotypic resistance testing in LMIC settings. One or more of these six DRMs was present in 61.2% of analyzed virus sequences from ART-nave individuals with intermediate or high-level TDR and 98.8% of analyzed virus sequences from individuals on a first-line NRTI/NNRTI-containing regimen with intermediate or high-level acquired drug resistance. The detection of one or more of these DRMs in an ART-nave individual or in a individual with VF on a first-line NRTI/NNRTI-containing regimen may be considered an indication for a protease inhibitor (PI)-containing regimen or closer virological monitoring based on cost-effectiveness or country policy.

    View details for DOI 10.1371/journal.pone.0145772

    View details for Web of Science ID 000367510500068

    View details for PubMedCentralID PMC4696791

  • Sustainable HIV treatment in Africa through viral-load-informed differentiated care NATURE Phillips, A., Shroufi, A., Vojnov, L., Cohn, J., Roberts, T., Ellman, T., Bonner, K., Rousseau, C., Garnett, G., Cambiano, V., Nakagawa, F., Ford, D., Bansi-Matharu, L., Miners, A., Lundgren, J. D., Eaton, J. W., Parkes-Ratanshi, R., Katz, Z., Maman, D., Ford, N., Vitoria, M., Doherty, M., Dowdy, D., Nichols, B., Murtagh, M., Wareham, M., Palamountain, K. M., Musanhu, C. C., Stevens, W., Katzenstein, D., Ciaranello, A., Barnabas, R., Braithwaite, R. S., Bendavid, E., Nathoo, K. J., van de Vijver, D., Wilson, D. P., Holmes, C., Bershteyn, A., Walker, S., Raizes, E., Jani, I., Nelson, L. J., Peeling, R., Terris-Prestholt, F., Murungu, J., Mutasa-Apollo, T., Hallett, T. B., Revill, P. 2015; 528 (7580): S68-S76

    Abstract

    There are inefficiencies in current approaches to monitoring patients on antiretroviral therapy in sub-Saharan Africa. Patients typically attend clinics every 1 to 3 months for clinical assessment. The clinic costs are comparable with the costs of the drugs themselves and CD4 counts are measured every 6 months, but patients are rarely switched to second-line therapies. To ensure sustainability of treatment programmes, a transition to more cost-effective delivery of antiretroviral therapy is needed. In contrast to the CD4 count, measurement of the level of HIV RNA in plasma (the viral load) provides a direct measure of the current treatment effect. Viral-load-informed differentiated care is a means of tailoring care so that those with suppressed viral load visit the clinic less frequently and attention is focussed on those with unsuppressed viral load to promote adherence and timely switching to a second-line regimen. The most feasible approach to measuring viral load in many countries is to collect dried blood spot samples for testing in regional laboratories; however, there have been concerns over the sensitivity and specificity of this approach to define treatment failure and the delay in returning results to the clinic. We use modelling to synthesize evidence and evaluate the cost-effectiveness of viral-load-informed differentiated care, accounting for limitations of dried blood sample testing. We find that viral-load-informed differentiated care using dried blood sample testing is cost-effective and is a recommended strategy for patient monitoring, although further empirical evidence as the approach is rolled out would be of value. We also explore the potential benefits of point-of-care viral load tests that may become available in the future.

    View details for DOI 10.1038/nature16046

    View details for Web of Science ID 000365606000013

    View details for PubMedCentralID PMC4932825

  • Lopinavir/Ritonavir Monotherapy as Second-line Antiretroviral Treatment in Resource-Limited Settings: Week 104 Analysis of AIDS Clinical Trials Group (ACTG) A5230 CLINICAL INFECTIOUS DISEASES Kumarasamy, N., Aga, E., Ribaudo, H. J., Wallis, C. L., Katzenstein, D. A., Stevens, W. S., Norton, M. R., Klingman, K. L., Hosseinipour, M. C., Crump, J. A., Supparatpinyo, K., Badal-Faesen, S., Bartlett, J. A. 2015; 60 (10): 1552-1558

    Abstract

    The AIDS Clinical Trials Group (ACTG) A5230 study evaluated lopinavir/ritonavir (LPV/r) monotherapy following virologic failure (VF) on first-line human immunodeficiency virus (HIV) regimens in Africa and Asia.Eligible subjects had received first-line regimens for at least 6 months and had plasma HIV-1 RNA levels 1000-200 000 copies/mL. All subjects received LPV/r 400/100 mg twice daily. VF was defined as failure to suppress to <400 copies/mL by week 24, or confirmed rebound to >400 copies/mL at or after week 16 following confirmed suppression. Subjects with VF added emtricitabine 200 mg/tenofovir 300 mg (FTC/TDF) once daily. The probability of continued HIV-1 RNA <400 copies/mL on LPV/r monotherapy through week 104 was estimated with a 95% confidence interval (CI); predictors of treatment success were evaluated with Cox proportional hazards models.One hundred twenty-three subjects were enrolled. Four subjects died and 2 discontinued prematurely; 117 of 123 (95%) completed 104 weeks. Through week 104, 49 subjects met the primary endpoint; 47 had VF, and 2 intensified treatment without VF. Of the 47 subjects with VF, 41 (33%) intensified treatment, and 39 of 41 subsequently achieved levels <400 copies/mL. The probability of continued suppression <400 copies/mL over 104 weeks on LPV/r monotherapy was 60% (95% CI, 50%-68%); 80%-85% maintained levels <400 copies/mL with FTC/TDF intensification as needed. Ultrasensitive assays on specimens with HIV-1 RNA level <400 copies/mL at weeks 24, 48, and 104 revealed that 61%, 62%, and 65% were suppressed to <40 copies/mL, respectively.LPV/r monotherapy after first-line VF with FTC/TDF intensification when needed provides durable suppression of HIV-1 RNA over 104 weeks.NCT00357552.

    View details for DOI 10.1093/cid/civ109

    View details for Web of Science ID 000353721300018

    View details for PubMedCentralID PMC4425828

  • Geographic and temporal trends in the molecular epidemiology and genetic mechanisms of transmitted HIV-1 drug resistance: an individual-patient- and sequence-level meta-analysis. PLoS medicine Rhee, S., Blanco, J. L., Jordan, M. R., Taylor, J., Lemey, P., Varghese, V., Hamers, R. L., Bertagnolio, S., Rinke de Wit, T. F., Aghokeng, A. F., Albert, J., Avi, R., Avila-Rios, S., Bessong, P. O., Brooks, J. I., Boucher, C. A., Brumme, Z. L., Busch, M. P., Bussmann, H., Chaix, M., Chin, B. S., D'Aquin, T. T., De Gascun, C. F., Derache, A., Descamps, D., Deshpande, A. K., Djoko, C. F., Eshleman, S. H., Fleury, H., Frange, P., Fujisaki, S., Harrigan, P. R., Hattori, J., Holguin, A., Hunt, G. M., Ichimura, H., Kaleebu, P., Katzenstein, D., Kiertiburanakul, S., Kim, J. H., Kim, S. S., Li, Y., Lutsar, I., Morris, L., Ndembi, N., Ng, K. P., Paranjape, R. S., Peeters, M., Poljak, M., Price, M. A., Ragonnet-Cronin, M. L., Reyes-Tern, G., Rolland, M., Sirivichayakul, S., Smith, D. M., Soares, M. A., Soriano, V. V., Ssemwanga, D., Stanojevic, M., Stefani, M. A., Sugiura, W., Sungkanuparph, S., Tanuri, A., Tee, K. K., Truong, H. M., Van De Vijver, D. A., Vidal, N., Yang, C., Yang, R., Yebra, G., Ioannidis, J. P., Vandamme, A., Shafer, R. W. 2015; 12 (4)

    Abstract

    Regional and subtype-specific mutational patterns of HIV-1 transmitted drug resistance (TDR) are essential for informing first-line antiretroviral (ARV) therapy guidelines and designing diagnostic assays for use in regions where standard genotypic resistance testing is not affordable. We sought to understand the molecular epidemiology of TDR and to identify the HIV-1 drug-resistance mutations responsible for TDR in different regions and virus subtypes.We reviewed all GenBank submissions of HIV-1 reverse transcriptase sequences with or without protease and identified 287 studies published between March 1, 2000, and December 31, 2013, with more than 25 recently or chronically infected ARV-nave individuals. These studies comprised 50,870 individuals from 111 countries. Each set of study sequences was analyzed for phylogenetic clustering and the presence of 93 surveillance drug-resistance mutations (SDRMs). The median overall TDR prevalence in sub-Saharan Africa (SSA), south/southeast Asia (SSEA), upper-income Asian countries, Latin America/Caribbean, Europe, and North America was 2.8%, 2.9%, 5.6%, 7.6%, 9.4%, and 11.5%, respectively. In SSA, there was a yearly 1.09-fold (95% CI: 1.05-1.14) increase in odds of TDR since national ARV scale-up attributable to an increase in non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance. The odds of NNRTI-associated TDR also increased in Latin America/Caribbean (odds ratio [OR] = 1.16; 95% CI: 1.06-1.25), North America (OR = 1.19; 95% CI: 1.12-1.26), Europe (OR = 1.07; 95% CI: 1.01-1.13), and upper-income Asian countries (OR = 1.33; 95% CI: 1.12-1.55). In SSEA, there was no significant change in the odds of TDR since national ARV scale-up (OR = 0.97; 95% CI: 0.92-1.02). An analysis limited to sequences with mixtures at less than 0.5% of their nucleotide positions-a proxy for recent infection-yielded trends comparable to those obtained using the complete dataset. Four NNRTI SDRMs-K101E, K103N, Y181C, and G190A-accounted for >80% of NNRTI-associated TDR in all regions and subtypes. Sixteen nucleoside reverse transcriptase inhibitor (NRTI) SDRMs accounted for >69% of NRTI-associated TDR in all regions and subtypes. In SSA and SSEA, 89% of NNRTI SDRMs were associated with high-level resistance to nevirapine or efavirenz, whereas only 27% of NRTI SDRMs were associated with high-level resistance to zidovudine, lamivudine, tenofovir, or abacavir. Of 763 viruses with TDR in SSA and SSEA, 725 (95%) were genetically dissimilar; 38 (5%) formed 19 sequence pairs. Inherent limitations of this study are that some cohorts may not represent the broader regional population and that studies were heterogeneous with respect to duration of infection prior to sampling.Most TDR strains in SSA and SSEA arose independently, suggesting that ARV regimens with a high genetic barrier to resistance combined with improved patient adherence may mitigate TDR increases by reducing the generation of new ARV-resistant strains. A small number of NNRTI-resistance mutations were responsible for most cases of high-level resistance, suggesting that inexpensive point-mutation assays to detect these mutations may be useful for pre-therapy screening in regions with high levels of TDR. In the context of a public health approach to ARV therapy, a reliable point-of-care genotypic resistance test could identify which patients should receive standard first-line therapy and which should receive a protease-inhibitor-containing regimen.

    View details for DOI 10.1371/journal.pmed.1001810

    View details for PubMedID 25849352

  • Geographic and Temporal Trends in the Molecular Epidemiology and Genetic Mechanisms of Transmitted HIV-1 Drug Resistance: An Individual-Patient- and Sequence-Level Meta-Analysis. PLoS medicine Rhee, S., Blanco, J. L., Jordan, M. R., Taylor, J., Lemey, P., Varghese, V., Hamers, R. L., Bertagnolio, S., de Wit, T. F., Aghokeng, A. F., Albert, J., Avi, R., Avila-Rios, S., Bessong, P. O., Brooks, J. I., Boucher, C. A., Brumme, Z. L., Busch, M. P., Bussmann, H., Chaix, M., Chin, B. S., D'Aquin, T. T., De Gascun, C. F., Derache, A., Descamps, D., Deshpande, A. K., Djoko, C. F., Eshleman, S. H., Fleury, H., Frange, P., Fujisaki, S., Harrigan, P. R., Hattori, J., Holguin, A., Hunt, G. M., Ichimura, H., Kaleebu, P., Katzenstein, D., Kiertiburanakul, S., Kim, J. H., Kim, S. S., Li, Y., Lutsar, I., Morris, L., Ndembi, N., Ng, K. P., Paranjape, R. S., Peeters, M., Poljak, M., Price, M. A., Ragonnet-Cronin, M. L., Reyes-Tern, G., Rolland, M., Sirivichayakul, S., Smith, D. M., Soares, M. A., Soriano, V. V., Ssemwanga, D., Stanojevic, M., Stefani, M. A., Sugiura, W., Sungkanuparph, S., Tanuri, A., Tee, K. K., Truong, H. M., Van De Vijver, D. A., Vidal, N., Yang, C., Yang, R., Yebra, G., Ioannidis, J. P., Vandamme, A., Shafer, R. W. 2015; 12 (4)

    View details for DOI 10.1371/journal.pmed.1001810

    View details for PubMedID 25849352

  • Impact of Drug Resistance-Associated Amino Acid Changes in HIV-1 Subtype C on Susceptibility to Newer Nonnucleoside Reverse Transcriptase Inhibitors ANTIMICROBIAL AGENTS AND CHEMOTHERAPY Basson, A. E., Rhee, S., Parry, C. M., El-Khatib, Z., Charalambous, S., de Oliveira, T., Pillay, D., Hoffmann, C., Katzenstein, D., Shafer, R. W., Morris, L. 2015; 59 (2): 960-971

    Abstract

    The objective of this study was to assess the phenotypic susceptibility of HIV-1 subtype C isolates, with nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance-associated amino acid changes, to newer NNRTIs. A panel of 52 site-directed mutants and 38 clinically derived HIV-1 subtype C clones was created, and the isolates were assessed for phenotypic susceptibility to etravirine (ETR), rilpivirine (RPV), efavirenz (EFV), and nevirapine (NVP) in an in vitro single-cycle phenotypic assay. The amino acid substitutions E138Q/R, Y181I/V, and M230L conferred high-level resistance to ETR, while K101P and Y181I/V conferred high-level resistance to RPV. Y181C, a major NNRTI resistance-associated amino acid substitution, caused decreased susceptibility to ETR and, to a lesser extent, RPV when combined with other mutations. These included N348I and T369I, amino acid changes in the connection domain that are not generally assessed during resistance testing. However, the prevalence of these genotypes among subtype C sequences was, in most cases, <1%. The more common EFV/NVP resistance-associated substitutions, such as K103N, V106M, and G190A, had no major impact on ETR or RPV susceptibility. The low-level resistance to RPV and ETR conferred by E138K was not significantly enhanced in the presence of M184V/I, unlike for EFV and NVP. Among patient samples, 97% were resistant to EFV and/or NVP, while only 24% and 16% were resistant to ETR and RPV, respectively. Overall, only a few, relatively rare NNRTI resistance-associated amino acid substitutions caused resistance to ETR and/or RPV in an HIV-1 subtype C background, suggesting that these newer NNRTIs would be effective in NVP/EFV-experienced HIV-1 subtype C-infected patients.

    View details for DOI 10.1128/AAC.04215-14

    View details for Web of Science ID 000348610000026

    View details for PubMedID 25421485

    View details for PubMedCentralID PMC4335849

  • HIV Drug Resistance Mutations in Proviral DNA from a Community Treatment Program PLOS ONE Derache, A., Shin, H., Balamane, M., White, E., Israelski, D., Klausner, J. D., Freeman, A. H., Katzenstein, D. 2015; 10 (1)

    Abstract

    Drug resistance mutations archived in resting memory CD4+ cells may persist despite suppression of HIV RNA to <50 copies/ml. We sequenced pol gene from proviral DNA among viremic and suppressed patients to identify drug resistance mutations.The Peninsula AIDS Research Cohort study enrolled and followed over 2 years 120 HIV infected patients from San Mateo and San Francisco Counties. HIV-1 pol genotyping by bulk sequencing was performed on 38 DNA and RNA from viremic patients and DNA only among 82 suppressed patients at baseline. Antiretroviral susceptibility was predicted by HIVDB.stanford.edu.Among 120 subjects, 81% were on antiretroviral therapy and had been treated for a median time of 7 years. Thirty-two viremic patients showed concordant RNA and DNA genotypes (84%); the discordant profiles were mainly observed in patients with low-level viremia. Among suppressed patients, 21 had drug resistance mutations in proviral DNA (26%) with potential resistance to one, two or three ARV classes in 16, 4 and 1 samples respectively.The high level of genotype concordance between DNA and RNA in viremic patients suggested that DNA genotyping might be used to assess drug resistance in resource-limited settings, and further investigation of extracted DNA from dried blood spots is needed. Drug resistance mutations in proviral DNA in 26% of subjects with less than 50 copies/ml pose a risk for the transmission of drug resistant virus with virologic failure, treatment interruption or decreased adherence.

    View details for DOI 10.1371/journal.pone.0117430

    View details for Web of Science ID 000350680700085

    View details for PubMedID 25635815

    View details for PubMedCentralID PMC4311981

  • Lopinavir/Ritonavir Monotherapy as Second-line Antiretroviral Treatment in Resource-Limited Settings: Week 104 Analysis of AIDS Clinical Trials Group (ACTG) A5230. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America Kumarasamy, N., Aga, E., Ribaudo, H. J., Wallis, C. L., Katzenstein, D. A., Stevens, W. S., Norton, M. R., Klingman, K. L., Hosseinipour, M. C., Crump, J. A., Supparatpinyo, K., Badal-Faesen, S., Bartlett, J. A. 2015; 60 (10): 1552?58

    Abstract

    The AIDS Clinical Trials Group (ACTG) A5230 study evaluated lopinavir/ritonavir (LPV/r) monotherapy following virologic failure (VF) on first-line human immunodeficiency virus (HIV) regimens in Africa and Asia.Eligible subjects had received first-line regimens for at least 6 months and had plasma HIV-1 RNA levels 1000-200 000 copies/mL. All subjects received LPV/r 400/100 mg twice daily. VF was defined as failure to suppress to <400 copies/mL by week 24, or confirmed rebound to >400 copies/mL at or after week 16 following confirmed suppression. Subjects with VF added emtricitabine 200 mg/tenofovir 300 mg (FTC/TDF) once daily. The probability of continued HIV-1 RNA <400 copies/mL on LPV/r monotherapy through week 104 was estimated with a 95% confidence interval (CI); predictors of treatment success were evaluated with Cox proportional hazards models.One hundred twenty-three subjects were enrolled. Four subjects died and 2 discontinued prematurely; 117 of 123 (95%) completed 104 weeks. Through week 104, 49 subjects met the primary endpoint; 47 had VF, and 2 intensified treatment without VF. Of the 47 subjects with VF, 41 (33%) intensified treatment, and 39 of 41 subsequently achieved levels <400 copies/mL. The probability of continued suppression <400 copies/mL over 104 weeks on LPV/r monotherapy was 60% (95% CI, 50%-68%); 80%-85% maintained levels <400 copies/mL with FTC/TDF intensification as needed. Ultrasensitive assays on specimens with HIV-1 RNA level <400 copies/mL at weeks 24, 48, and 104 revealed that 61%, 62%, and 65% were suppressed to <40 copies/mL, respectively.LPV/r monotherapy after first-line VF with FTC/TDF intensification when needed provides durable suppression of HIV-1 RNA over 104 weeks.NCT00357552.

    View details for PubMedID 25694653

    View details for PubMedCentralID PMC4425828

  • Sustainable HIV treatment in Africa through viral-load-informed differentiated care. Nature Phillips, A., Shroufi, A., Vojnov, L., Cohn, J., Roberts, T., Ellman, T., Bonner, K., Rousseau, C., Garnett, G., Cambiano, V., Nakagawa, F., Ford, D., Bansi-Matharu, L., Miners, A., Lundgren, J. D., Eaton, J. W., Parkes-Ratanshi, R., Katz, Z., Maman, D., Ford, N., Vitoria, M., Doherty, M., Dowdy, D., Nichols, B., Murtagh, M., Wareham, M., Palamountain, K. M., Chakanyuka Musanhu, C., Stevens, W., Katzenstein, D., Ciaranello, A., Barnabas, R., Braithwaite, R. S., Bendavid, E., Nathoo, K. J., van de Vijver, D., Wilson, D. P., Holmes, C., Bershteyn, A., Walker, S., Raizes, E., Jani, I., Nelson, L. J., Peeling, R., Terris-Prestholt, F., Murungu, J., Mutasa-Apollo, T., Hallett, T. B., Revill, P. 2015; 528 (7580): S68?76

    Abstract

    There are inefficiencies in current approaches to monitoring patients on antiretroviral therapy in sub-Saharan Africa. Patients typically attend clinics every 1 to 3 months for clinical assessment. The clinic costs are comparable with the costs of the drugs themselves and CD4 counts are measured every 6 months, but patients are rarely switched to second-line therapies. To ensure sustainability of treatment programmes, a transition to more cost-effective delivery of antiretroviral therapy is needed. In contrast to the CD4 count, measurement of the level of HIV RNA in plasma (the viral load) provides a direct measure of the current treatment effect. Viral-load-informed differentiated care is a means of tailoring care so that those with suppressed viral load visit the clinic less frequently and attention is focussed on those with unsuppressed viral load to promote adherence and timely switching to a second-line regimen. The most feasible approach to measuring viral load in many countries is to collect dried blood spot samples for testing in regional laboratories; however, there have been concerns over the sensitivity and specificity of this approach to define treatment failure and the delay in returning results to the clinic. We use modelling to synthesize evidence and evaluate the cost-effectiveness of viral-load-informed differentiated care, accounting for limitations of dried blood sample testing. We find that viral-load-informed differentiated care using dried blood sample testing is cost-effective and is a recommended strategy for patient monitoring, although further empirical evidence as the approach is rolled out would be of value. We also explore the potential benefits of point-of-care viral load tests that may become available in the future.

    View details for PubMedID 26633768

  • HIV-1 Drug Resistance Mutations: Potential Applications for Point-of-Care Genotypic Resistance Testing. PloS one Rhee, S., Jordan, M. R., Raizes, E., Chua, A., Parkin, N., Kantor, R., van Zyl, G. U., Mukui, I., Hosseinipour, M. C., Frenkel, L. M., Ndembi, N., Hamers, R. L., Rinke de Wit, T. F., Wallis, C. L., Gupta, R. K., Fokam, J., Zeh, C., Schapiro, J. M., Carmona, S., Katzenstein, D., Tang, M., Aghokeng, A. F., de Oliveira, T., Wensing, A. M., Gallant, J. E., Wainberg, M. A., Richman, D. D., Fitzgibbon, J. E., Schito, M., Bertagnolio, S., Yang, C., Shafer, R. W. 2015; 10 (12)

    Abstract

    The increasing prevalence of acquired and transmitted HIV-1 drug resistance is an obstacle to successful antiretroviral therapy (ART) in the low- and middle-income countries (LMICs) hardest hit by the HIV-1 pandemic. Genotypic drug resistance testing could facilitate the choice of initial ART in areas with rising transmitted drug resistance (TDR) and enable care-providers to determine which individuals with virological failure (VF) on a first- or second-line ART regimen require a change in treatment. An inexpensive near point-of-care (POC) genotypic resistance test would be useful in settings where the resources, capacity, and infrastructure to perform standard genotypic drug resistance testing are limited. Such a test would be particularly useful in conjunction with the POC HIV-1 viral load tests that are currently being introduced in LMICs. A POC genotypic resistance test is likely to involve the use of allele-specific point mutation assays for detecting drug-resistance mutations (DRMs). This study proposes that two major nucleoside reverse transcriptase inhibitor (NRTI)-associated DRMs (M184V and K65R) and four major NNRTI-associated DRMs (K103N, Y181C, G190A, and V106M) would be the most useful for POC genotypic resistance testing in LMIC settings. One or more of these six DRMs was present in 61.2% of analyzed virus sequences from ART-nave individuals with intermediate or high-level TDR and 98.8% of analyzed virus sequences from individuals on a first-line NRTI/NNRTI-containing regimen with intermediate or high-level acquired drug resistance. The detection of one or more of these DRMs in an ART-nave individual or in a individual with VF on a first-line NRTI/NNRTI-containing regimen may be considered an indication for a protease inhibitor (PI)-containing regimen or closer virological monitoring based on cost-effectiveness or country policy.

    View details for DOI 10.1371/journal.pone.0145772

    View details for PubMedID 26717411

    View details for PubMedCentralID PMC4696791

  • HIV diversity and drug resistance from plasma and non-plasma analytes in a large treatment programme in western Kenya JOURNAL OF THE INTERNATIONAL AIDS SOCIETY Kantor, R., DeLong, A., Balamane, M., Schreier, L., Lloyd, R. M., Injera, W., Kamle, L., Mambo, F., Muyonga, S., Katzenstein, D., Hogan, J., Buziba, N., Diero, L. 2014; 17
  • Drug Susceptibility and Resistance Mutations After First-Line Failure in Resource Limited Settings CLINICAL INFECTIOUS DISEASES Wallis, C. L., Aga, E., Ribaudo, H., Saravanan, S., Norton, M., Stevens, W., Kumarasamy, N., Bartlett, J., Katzenstein, D. 2014; 59 (5): 706-715

    Abstract

    The development of drug resistance to nucleoside reverse transcriptase inhibitors (NRTIs) and nonnucleoside reverse transcriptase inhibitors (NNRTIs) has been associated with baseline human immunodeficiency virus (HIV)-1 RNA level (VL), CD4 cell counts (CD4), subtype, and treatment failure duration. This study describes drug resistance and levels of susceptibility after first-line virologic failure in individuals from Thailand, South Africa, India, Malawi, Tanzania.CD4 and VL were captured at AIDs Clinical Trial Group (ACTG) A5230 study entry, a study of lopinavir/ritonavir (LPV/r) monotherapy after first-line virologic failure on an NNRTI regimen. HIV drug-resistance mutation associations with subtype, site, study entry VL, and CD4 were evaluated using Fisher exact and Kruskall-Wallis tests.Of the 207 individuals who were screened for A5230, sequence data were available for 148 individuals. Subtypes observed: subtype C (n = 97, 66%) AE (n = 27, 18%), A1 (n = 12, 8%), and D (n = 10, 7%). Of the 148 individuals, 93% (n = 138) and 96% (n = 142) had at least 1 reverse transcriptase (RT) mutation associated with NRTI and NNRTI resistance, respectively. The number of NRTI mutations was significantly associated with a higher study screening VL and lower study screening CD4 (P < .001). Differences in drug-resistance patterns in both NRTI and NNRTI were observed by site.The degree of NNRTI and NRTI resistance after first-line virologic failure was associated with higher VL at study entry. Thirty-two percent of individuals remained fully susceptible to etravirine and rilpivirine, protease inhibitor resistance was rare. Some level of susceptibility to NRTI remained; however, VL monitoring and earlier virologic failure detection may result in lower NRTI resistance.

    View details for DOI 10.1093/cid/ciu314

    View details for Web of Science ID 000342921100022

    View details for PubMedID 24795328

    View details for PubMedCentralID PMC4148601

  • Association between Latent Proviral Characteristics and Immune Activation in Antiretrovirus-Treated Human Immunodeficiency Virus Type 1-Infected Adults. Journal of virology Liang, E. C., Sceats, L., Bayless, N. L., Strauss-Albee, D. M., Kubo, J., Grant, P. M., Furman, D., Desai, M., Katzenstein, D. A., Davis, M. M., Zolopa, A. R., Blish, C. A. 2014; 88 (15): 8629-8639

    Abstract

    Generalized immune activation during HIV infection is associated with an increased risk of cardiovascular disease, neurocognitive disease, osteoporosis, metabolic disorders, and physical frailty. The mechanisms driving this immune activation are poorly understood, particularly for individuals effectively treated with antiretroviral medications. We hypothesized that viral characteristics such as sequence diversity may play a role in driving HIV-associated immune activation. We therefore sequenced proviral DNA isolated from peripheral blood mononuclear cells from HIV-infected individuals on fully suppressive antiretroviral therapy. We performed phylogenetic analyses, calculated viral diversity and divergence in the env and pol genes, and determined coreceptor tropism and the frequency of drug resistance mutations. Comprehensive immune profiling included quantification of immune cell subsets, plasma cytokine levels, and intracellular signaling responses in T cells, B cells, and monocytes. These antiretroviral therapy-treated HIV-infected individuals exhibited a wide range of diversity and divergence in both env and pol genes. However, proviral diversity and divergence in env and pol, coreceptor tropism, and the level of drug resistance did not significantly correlate with markers of immune activation. A clinical history of virologic failure was also not significantly associated with levels of immune activation, indicating that a history of virologic failure does not inexorably lead to increased immune activation as long as suppressive antiretroviral medications are provided. Overall, this study demonstrates that latent viral diversity is unlikely to be a major driver of persistent HIV-associated immune activation.Chronic immune activation, which is associated with cardiovascular disease, neurologic disease, and early aging, is likely to be a major driver of morbidity and mortality in HIV-infected individuals. Although treatment of HIV with antiretroviral medications decreases the level of immune activation, levels do not return to normal. The factors driving this persistent immune activation, particularly during effective treatment, are poorly understood. In this study, we investigated whether characteristics of the latent, integrated HIV provirus that persists during treatment are associated with immune activation. We found no relationship between latent viral characteristics and immune activation in treated individuals, indicating that qualities of the provirus are unlikely to be a major driver of persistent inflammation. We also found that individuals who had previously failed treatment but were currently effectively treated did not have significantly increased levels of immune activation, providing hope that past treatment failures do not have a lifelong "legacy" impact.

    View details for DOI 10.1128/JVI.01257-14

    View details for PubMedID 24850730

    View details for PubMedCentralID PMC4135944

  • Role of oral candidiasis in TB and HIV co-infection: AIDS Clinical Trial Group Protocol A5253 INTERNATIONAL JOURNAL OF TUBERCULOSIS AND LUNG DISEASE Shiboski, C. H., Chen, H., Ghannoum, M. A., Komarow, L., Evans, S., Mukherjee, P. K., Isham, N., KATZENSTEIN, D., Asmelash, A., Omozoarhe, A. E., Gengiah, S., Allen, R., Tripathy, S., Swindells, S. 2014; 18 (6): 682-688

    Abstract

    To evaluate the association between oral candidiasis and tuberculosis (TB) in human immunodeficiency virus (HIV) infected individuals in sub-Saharan Africa, and to investigate oral candidiasis as a potential tool for TB case finding.Protocol A5253 was a cross-sectional study designed to improve the diagnosis of pulmonary TB in HIV-infected adults in high TB prevalence countries. Participants received an oral examination to detect oral candidiasis. We estimated the association between TB disease and oral candidiasis using logistic regression, and sensitivity, specificity and predictive values.Of 454 participants with TB culture results enrolled in African sites, the median age was 33 years, 71% were female and the median CD4 count was 257 cells/mm(3). Fifty-four (12%) had TB disease; the prevalence of oral candidiasis was significantly higher among TB cases (35%) than among non-TB cases (16%, P < 0.001). The odds of having TB was 2.4 times higher among those with oral candidiasis when controlling for CD4 count and antifungals (95%CI 1.2-4.7, P = 0.01). The sensitivity of oral candidiasis as a predictor of TB was 35% (95%CI 22-48) and the specificity 85% (95%CI 81-88).We found a strong association between oral candidiasis and TB disease, independent of CD4 count, suggesting that in resource-limited settings, oral candidiasis may provide clinical evidence for increased risk of TB and contribute to TB case finding.

    View details for DOI 10.5588/ijtld.13.0729

    View details for Web of Science ID 000336198700012

    View details for PubMedID 24903939

    View details for PubMedCentralID PMC4157598

  • HIV-1 RNA Levels and Antiretroviral Drug Resistance in Blood and Non-Blood Compartments from HIV-1-Infected Men and Women enrolled in AIDS Clinical Trials Group Study A5077 PLOS ONE Kantor, R., Bettendorf, D., Bosch, R. J., Mann, M., Katzenstein, D., Cu-Uvin, S., D'Aquila, R., Frenkel, L., Fiscus, S., Coombs, R. 2014; 9 (4)

    Abstract

    Detectable HIV-1 in body compartments can lead to transmission and antiretroviral resistance. Although sex differences in viral shedding have been demonstrated, mechanisms and magnitude are unclear. We compared RNA levels in blood, genital-secretions and saliva; and drug resistance in plasma and genital-secretions of men and women starting/changing antiretroviral therapy (ART) in the AIDS Clinical Trials Group (ACTG) 5077 study.Blood, saliva and genital-secretions (compartment fluids) were collected from HIV-infected adults (? 13 years) at 14 United-States sites, who were initiating or changing ART with plasma viral load (VL) ? 2,000 copies/mL. VL testing was performed on all compartment fluids and HIV resistance genotyping on plasma and genital-secretions. Spearman rank correlations were used to evaluate concordance and Fisher's and McNemar's exact tests to compare VL between sexes and among compartments.Samples were available for 143 subjects; 36% treated (23 men, 29 women) and 64% 'untreated' (40 men, 51 women). RNA detection was significantly more frequent in plasma (100%) than genital-secretions (57%) and saliva (64%) (P<0.001). A higher proportion of men had genital shedding versus women (78% versus 41%), and RNA detection was more frequent in saliva versus genital-secretions in women when adjusted for censoring at the limit of assay detection. Inter-compartment fluid VL concordance was low in both sexes. In 22 (13 men, 9 women) paired plasma-genital-secretion genotypes from treated subjects, most had detectable resistance in both plasma (77%) and genital-secretions (68%). Resistance discordance was observed between compartments in 14% of subjects.HIV shedding and drug resistance detection prior to initiation/change of ART in ACTG 5077 subjects differed among tissues and between sexes, making the gold standard blood-plasma compartment assessment not fully representative of HIV at other tissue sites. Mechanisms of potential sex-dependent tissue compartmentalization should be further characterized to aid in optimizing treatment and prevention of HIV transmission.ClinicalTrials.gov NCT00007488.

    View details for DOI 10.1371/journal.pone.0093537

    View details for Web of Science ID 000334105000066

    View details for PubMedID 24699474

    View details for PubMedCentralID PMC3974754

  • Outcomes by Sex Following Treatment Initiation With Atazanavir Plus Ritonavir or Efavirenz With Abacavir/Lamivudine or Tenofovir/Emtricitabine CLINICAL INFECTIOUS DISEASES Smith, K. Y., Tierney, C., Mollan, K., Venuto, C. S., Budhathoki, C., Ma, Q., Morse, G. D., Sax, P., Katzenstein, D., Godfrey, C., Fischl, M., Daar, E. S., Collier, A. C. 2014; 58 (4): 555-563

    Abstract

    We aimed to evaluate treatment responses to atazanavir plus ritonavir (ATV/r) or efavirenz (EFV) in initial antiretroviral regimens among women and men, and determine if treatment outcomes differ by sex.We performed a randomized trial of open-label ATV/r or EFV combined with abacavir/lamivudine (ABC/3TC) or tenofovir/emtricitabine (TDF/FTC) in 1857 human immunodeficiency virus type 1-infected, treatment-naive persons enrolled between September 2005 and November 2007 at 59 sites in the United States and Puerto Rico. Associations of sex with 3 primary study endpoints of time to virologic failure, safety, and tolerability events were analyzed using Cox proportional hazards models. Model-based population pharmacokinetic analysis was performed using nonlinear mixed effects modeling (NONMEM version VII).Of 1857 participants, 322 were women. Women assigned to ATV/r had a higher risk of virologic failure with either nucleoside reverse transcriptase inhibitor backbone than women assigned to EFV, or men assigned to ATV/r. The effects of ATV/r and EFV upon safety and tolerability risk did not differ significantly by sex. With ABC/3TC, women had a significantly higher (32%) safety risk compared to men; with TDF/FTC, the safety risk was 20% larger for women compared to men, but not statistically significant. Women had slower ATV clearance and higher predose levels of ATV compared to men. Self-reported adherence did not differ significantly by sex.This is the first randomized clinical trial to identify a significantly earlier time to virologic failure in women randomized to ATV/r compared to women randomized to EFV. This finding has important clinical implications given that boosted protease inhibitors are often favored over EFV in women of childbearing potential.NCT00118898.

    View details for DOI 10.1093/cid/cit747

    View details for Web of Science ID 000331097800020

    View details for PubMedID 24253247

    View details for PubMedCentralID PMC3905755

  • HIV RNA and genotype in resource-limited settings: can we do better? Clinical infectious diseases : an official publication of the Infectious Diseases Society of America Katzenstein, D. A. 2014; 58 (1): 110?12

    View details for PubMedID 24076967

  • HIV diversity and drug resistance from plasma and non-plasma analytes in a large treatment programme in western Kenya. Journal of the International AIDS Society Kantor, R., DeLong, A., Balamane, M., Schreier, L., Lloyd, R. M., Injera, W., Kamle, L., Mambo, F., Muyonga, S., Katzenstein, D., Hogan, J., Buziba, N., Diero, L. 2014; 17: 19262

    Abstract

    Antiretroviral resistance leads to treatment failure and resistance transmission. Resistance data in western Kenya are limited. Collection of non-plasma analytes may provide additional resistance information.We assessed HIV diversity using the REGA tool, transmitted resistance by the WHO mutation list and acquired resistance upon first-line failure by the IAS-USA mutation list, at the Academic Model Providing Access to Healthcare (AMPATH), a major treatment programme in western Kenya. Plasma and four non-plasma analytes, dried blood-spots (DBS), dried plasma-spots (DPS), ViveST(TM)-plasma (STP) and ViveST-blood (STB), were compared to identify diversity and evaluate sequence concordance.Among 122 patients, 62 were treatment-nave and 60 treatment-experienced; 61% were female, median age 35 years, median CD4 182 cells/L, median viral-load 4.6 log10 copies/mL. One hundred and ninety-six sequences were available for 107/122 (88%) patients, 58/62 (94%) treatment-nave and 49/60 (82%) treated; 100/122 (82%) plasma, 37/78 (47%) attempted DBS, 16/45 (36%) attempted DPS, 14/44 (32%) attempted STP from fresh plasma and 23/34 (68%) from frozen plasma, and 5/42 (12%) attempted STB. Plasma and DBS genotyping success increased at higher VL and shorter shipment-to-genotyping time. Main subtypes were A (62%), D (15%) and C (6%). Transmitted resistance was found in 1.8% of plasma sequences, and 7% combining analytes. Plasma resistance mutations were identified in 91% of treated patients, 76% NRTI, 91% NNRTI; 76% dual-class; 60% with intermediate-high predicted resistance to future treatment options; with novel mutation co-occurrence patterns. Nearly 88% of plasma mutations were identified in DBS, 89% in DPS and 94% in STP. Of 23 discordant mutations, 92% in plasma and 60% in non-plasma analytes were mixtures. Mean whole-sequence discordance from frozen plasma reference was 1.1% for plasma-DBS, 1.2% plasma-DPS, 2.0% plasma-STP and 2.3% plasma-STB. Of 23 plasma-STP discordances, one mutation was identified in plasma and 22 in STP (p<0.05). Discordance was inversely significantly related to VL for DBS.In a large treatment programme in western Kenya, we report high HIV-1 subtype diversity; low plasma transmitted resistance, increasing when multiple analytes were combined; and high-acquired resistance with unique mutation patterns. Resistance surveillance may be augmented by using non-plasma analytes for lower-cost genotyping in resource-limited settings.

    View details for PubMedID 25413893

  • An affordable HIV-1 drug resistance monitoring method for resource limited settings. Journal of visualized experiments : JoVE Manasa, J., Danaviah, S., Pillay, S., Padayachee, P., Mthiyane, H., Mkhize, C., Lessells, R. J., Seebregts, C., de Wit, T. F., Viljoen, J., Katzenstein, D., de Oliveira, T. 2014

    Abstract

    HIV-1 drug resistance has the potential to seriously compromise the effectiveness and impact of antiretroviral therapy (ART). As ART programs in sub-Saharan Africa continue to expand, individuals on ART should be closely monitored for the emergence of drug resistance. Surveillance of transmitted drug resistance to track transmission of viral strains already resistant to ART is also critical. Unfortunately, drug resistance testing is still not readily accessible in resource limited settings, because genotyping is expensive and requires sophisticated laboratory and data management infrastructure. An open access genotypic drug resistance monitoring method to manage individuals and assess transmitted drug resistance is described. The method uses free open source software for the interpretation of drug resistance patterns and the generation of individual patient reports. The genotyping protocol has an amplification rate of greater than 95% for plasma samples with a viral load >1,000 HIV-1 RNA copies/ml. The sensitivity decreases significantly for viral loads <1,000 HIV-1 RNA copies/ml. The method described here was validated against a method of HIV-1 drug resistance testing approved by the United States Food and Drug Administration (FDA), the Viroseq genotyping method. Limitations of the method described here include the fact that it is not automated and that it also failed to amplify the circulating recombinant form CRF02_AG from a validation panel of samples, although it amplified subtypes A and B from the same panel.

    View details for DOI 10.3791/51242

    View details for PubMedID 24747156

    View details for PubMedCentralID PMC4024245

  • Drug Resistance Mutations from Whole Blood Proviral DNA Among Patients on Antiretroviral Drugs in Zimbabwe CURRENT HIV RESEARCH Chimukangara, B., Gwanzura, L., Mitchell, R., Katzenstein, D., Masimirembwa, C. 2014; 12 (5): 309-316

    Abstract

    There are more than 500 000 HIV-infected people on antiretroviral treatment (ART) in Zimbabwe with very limited laboratory monitoring. To ensure effective treatment and prevent transmission of drug resistance, affordable treatment monitoring is needed to guide individual treatment.125 whole blood samples from patients on first-line ART were investigated for drug resistance mutations using an in-house genotypic testing method. Patients had been on HIV reverse transcriptase inhibitors only, with some having been on both HIV and TB treatment. DNA was extracted from whole blood; amplicons were generated by nested PCR and sequenced. Drug resistance mutations were determined using the Stanford HIV drug resistance database. Exact statistics were used to investigate relationships between drug resistance and predisposing factors.From 125 samples, 108 were successfully analyzed for drug resistance mutations. 11 of the 108 sequences had drug resistance mutations; predominantly M184V and Y181C. For a 100-cell increase in CD4 count, the odds of being resistant were 61% lower than those with the baseline CD4 count (p = 0.04, CI: 0.34-0.98). There was no association between concurrent HIV/TB treatment and drug resistance (p = 0.41).Although plasma samples are recommended for genotypic testing, the cost of analyzing plasma RNA makes it less feasible in resource limited settings. Lower cost DNA drug resistance testing from whole blood samples was assessed as a treatment-monitoring tool among patients followed by CD4 and clinical monitoring only. The infrequent detection of resistance and higher CD4 is consistent with effective first-line treatment. Further investigation of proviral DNA as a tool to identify drug resistance mutations is warranted.

    View details for Web of Science ID 000347469000001

    View details for PubMedID 25323793

  • Early Virologic Response to Abacavir/Lamivudine and Tenofovir/Emtricitabine During ACTG A5202 HIV CLINICAL TRIALS Grant, P. M., Tierney, C., Budhathoki, C., Daar, E. S., Sax, P. E., Collier, A. C., Fischl, M. A., Zolopa, A. R., Balamane, M., Katzenstein, D. 2013; 14 (6): 284-291

    Abstract

    ACTG A5202 randomized treatment-nave individuals to tenofovir-emtricitabine (TDF/FTC) or abacavir-lamivudine (ABC/3TC) combined with efavirenz (EFV) or atazanavir/ritonavir (ATV/r). Individuals in the high screening viral load (VL) stratum (?100,000 copies/mL) had increased rates of virologic failure with ABC/3TC.To compare regimen-specific early virologic response.Using Wilcoxon rank-sum tests, we compared regimen-specific VL changes from entry to week 4 in A5202 subjects (N = 1,813) and from entry to week 1, 2, and 4 in substudy subjects (n = 179). We evaluated associations between week 4 VL change and time to virologic failure with Cox proportional hazards models.TDF/FTC and ABC/3TC produced similar week 4 VL declines in the entire study population and in the high VL stratum. EFV produced greater VL declines from baseline at week 4 than ATV/r (median -2.1 vs -1.9 log10 copies/mL; P < .001). In the substudy of subjects with week 1, 2, and 4 VL data, there was no difference in VL decline in individuals randomized to TDF/FTC versus ABC/3TC, but EFV resulted in greater VL decline from entry at each of these timepoints than ATV/r. Smaller week 4 VL decline was associated with increased risk of virologic failure.Within all treatment arms, a less robust week 4 virologic response was associated with higher risk for subsequent virologic failure. However, between-regimen differences in week 4 VL declines did not parallel the previously reported differences in longer term virologic efficacy in A5202, suggesting that between-regimen differences in responses were not due to intrinsic differences in antiviral activity.

    View details for DOI 10.1310/hct1408-284

    View details for Web of Science ID 000328443500003

    View details for PubMedID 24334181

  • Prototypical Recombinant Multi-Protease-Inhibitor-Resistant Infectious Molecular Clones of Human Immunodeficiency Virus Type 1 ANTIMICROBIAL AGENTS AND CHEMOTHERAPY Varghese, V., Mitsuya, Y., Fessel, W. J., Liu, T. F., Melikian, G. L., Katzenstein, D. A., Schiffer, C. A., Holmes, S. P., Shafer, R. W. 2013; 57 (9): 4290-4299

    Abstract

    The many genetic manifestations of HIV-1 protease inhibitor (PI) resistance present challenges to research into the mechanisms of PI-resistance and the assessment of new PIs. To address these challenges, we created a panel of recombinant multi-PI resistant infectious molecular clones designed to represent the spectrum of clinically relevant multi-PI resistant viruses. To assess the representativeness of this panel, we examined the sequences of the panel's viruses in the context of a correlation network of PI-resistance amino acid substitutions in sequences from more than 10,000 patients. The panel of recombinant infectious molecular clones comprised 29 of 41 study-defined PI-resistance amino acid substitutions and 23 of the 27 tightest amino acid substitution clusters. Based on their phenotypic properties, the clones were classified into four groups with increasing cross-resistance to the PIs most commonly used for salvage therapy: lopinavir (LPV), tipranavir (TPV), and darunavir (DRV). The panel of recombinant infectious molecular clones has been made available without restriction through the NIH AIDS Research and Reference Reagent Program. The public availability of the panel makes it possible to compare the inhibitory activity of different PIs with one another. The diversity of the panel and the high-level PI resistance of its clones suggest that investigational PIs active against the clones in this panel will retain antiviral activity against most, if not all clinically relevant PI-resistant viruses.

    View details for DOI 10.1128/AAC.00614-13

    View details for Web of Science ID 000323285500025

  • Capacity building and predictors of success for HIV-1 drug resistance testing in the Asia-Pacific region and Africa JOURNAL OF THE INTERNATIONAL AIDS SOCIETY Land, S., Zhou, J., Cunningham, P., Sohn, A. H., Singtoroj, T., Katzenstein, D., Mann, M., Sayer, D., Kantor, R. 2013; 16

    Abstract

    The TREAT Asia Quality Assessment Scheme (TAQAS) was developed as a quality assessment programme through expert education and training, for laboratories in the Asia-Pacific and Africa that perform HIV drug-resistance (HIVDR) genotyping. We evaluated the programme performance and factors associated with high-quality HIVDR genotyping.Laboratories used their standard protocols to test panels of human immunodeficiency virus (HIV)-positive plasma samples or electropherograms. Protocols were documented and performance was evaluated according to a newly developed scoring system, agreement with panel-specific consensus sequence, and detection of drug-resistance mutations (DRMs) and mixtures of wild-type and resistant virus (mixtures). High-quality performance was defined as detection of ?95% DRMs.Over 4.5 years, 23 participating laboratories in 13 countries tested 45 samples (30 HIV-1 subtype B; 15 non-B subtypes) in nine panels. Median detection of DRMs was 88-98% in plasma panels and 90-97% in electropherogram panels. Laboratories were supported to amend and improve their test outcomes as appropriate. Three laboratories that detected <80% DRMs in early panels demonstrated subsequent improvement. Sample complexity factors - number of DRMs (p<0.001) and number of DRMs as mixtures (p<0.001); and laboratory performance factors - detection of mixtures (p<0.001) and agreement with consensus sequence (p<0.001), were associated with high performance; sample format (plasma or electropherogram), subtype and genotyping protocol were not.High-quality HIVDR genotyping was achieved in the TAQAS collaborative laboratory network. Sample complexity and detection of mixtures were associated with performance quality. Laboratories conducting HIVDR genotyping are encouraged to participate in quality assessment programmes.

    View details for DOI 10.7448/IAS.16.1.18580

    View details for Web of Science ID 000326491600001

    View details for PubMedID 23845227

    View details for PubMedCentralID PMC3709369

  • Nucleoside reverse transcriptase inhibitor resistance mutations associated with first-line stavudine-containing antiretroviral therapy: programmatic implications for countries phasing out stavudine. journal of infectious diseases Tang, M. W., Rhee, S., Bertagnolio, S., Ford, N., Holmes, S., Sigaloff, K. C., Hamers, R. L., de Wit, T. F., Fleury, H. J., Kanki, P. J., Ruxrungtham, K., Hawkins, C. A., Wallis, C. L., Stevens, W., van Zyl, G. U., Manosuthi, W., Hosseinipour, M. C., Ngo-Giang-Huong, N., Belec, L., Peeters, M., Aghokeng, A., Bunupuradah, T., Burda, S., Cane, P., Cappelli, G., Charpentier, C., Dagnra, A. Y., Deshpande, A. K., El-Katib, Z., Eshleman, S. H., Fokam, J., Gody, J., Katzenstein, D., Koyalta, D. D., Kumwenda, J. J., Lallemant, M., Lynen, L., Marconi, V. C., Margot, N. A., Moussa, S., Ndung'u, T., Nyambi, P. N., Orrell, C., Schapiro, J. M., Schuurman, R., Sirivichayakul, S., Smith, D., Zolfo, M., Jordan, M. R., Shafer, R. W. 2013; 207: S70-7

    Abstract

    Background The World Health Organization Antiretroviral Treatment Guidelines recommend phasing-out stavudine because of its risk of long-term toxicity. There are two mutational pathways of stavudine resistance with different implications for zidovudine and tenofovir cross-resistance, the primary candidates for replacing stavudine. However, because resistance testing is rarely available in resource-limited settings, it is critical to identify the cross-resistance patterns associated with first-line stavudine failure. Methods We analyzed HIV-1 resistance mutations following first-line stavudine failure from 35 publications comprising 1,825 individuals. We also assessed the influence of concomitant nevirapine vs. efavirenz, therapy duration, and HIV-1 subtype on the proportions of mutations associated with zidovudine vs. tenofovir cross-resistance. Results Mutations with preferential zidovudine activity, K65R or K70E, occurred in 5.3% of individuals. Mutations with preferential tenofovir activity, ?two thymidine analog mutations (TAMs) or Q151M, occurred in 22% of individuals. Nevirapine increased the risk of TAMs, K65R, and Q151M. Longer therapy increased the risk of TAMs and Q151M but not K65R. Subtype C and CRF01_AE increased the risk of K65R, but only CRF01_AE increased the risk of K65R without Q151M. Conclusions Regardless of concomitant nevirapine vs. efavirenz, therapy duration, or subtype, tenofovir was more likely than zidovudine to retain antiviral activity following first-line d4T therapy.

    View details for DOI 10.1093/infdis/jit114

    View details for PubMedID 23687292

    View details for PubMedCentralID PMC3657117

  • Nucleoside reverse transcriptase inhibitor resistance mutations associated with first-line Stavudine-containing antiretroviral therapy: programmatic implications for countries phasing out Stavudine. journal of infectious diseases Tang, M. W., Rhee, S., Bertagnolio, S., Ford, N., Holmes, S., Sigaloff, K. C., Hamers, R. L., de Wit, T. F., Fleury, H. J., Kanki, P. J., Ruxrungtham, K., Hawkins, C. A., Wallis, C. L., Stevens, W., van Zyl, G. U., Manosuthi, W., Hosseinipour, M. C., Ngo-Giang-Huong, N., Belec, L., Peeters, M., Aghokeng, A., Bunupuradah, T., Burda, S., Cane, P., Cappelli, G., Charpentier, C., Dagnra, A. Y., Deshpande, A. K., El-Katib, Z., Eshleman, S. H., Fokam, J., Gody, J., Katzenstein, D., Koyalta, D. D., Kumwenda, J. J., Lallemant, M., Lynen, L., Marconi, V. C., Margot, N. A., Moussa, S., Ndung'u, T., Nyambi, P. N., Orrell, C., Schapiro, J. M., Schuurman, R., Sirivichayakul, S., Smith, D., Zolfo, M., Jordan, M. R., Shafer, R. W. 2013; 207: S70-7

    Abstract

    Background The World Health Organization Antiretroviral Treatment Guidelines recommend phasing-out stavudine because of its risk of long-term toxicity. There are two mutational pathways of stavudine resistance with different implications for zidovudine and tenofovir cross-resistance, the primary candidates for replacing stavudine. However, because resistance testing is rarely available in resource-limited settings, it is critical to identify the cross-resistance patterns associated with first-line stavudine failure. Methods We analyzed HIV-1 resistance mutations following first-line stavudine failure from 35 publications comprising 1,825 individuals. We also assessed the influence of concomitant nevirapine vs. efavirenz, therapy duration, and HIV-1 subtype on the proportions of mutations associated with zidovudine vs. tenofovir cross-resistance. Results Mutations with preferential zidovudine activity, K65R or K70E, occurred in 5.3% of individuals. Mutations with preferential tenofovir activity, ?two thymidine analog mutations (TAMs) or Q151M, occurred in 22% of individuals. Nevirapine increased the risk of TAMs, K65R, and Q151M. Longer therapy increased the risk of TAMs and Q151M but not K65R. Subtype C and CRF01_AE increased the risk of K65R, but only CRF01_AE increased the risk of K65R without Q151M. Conclusions Regardless of concomitant nevirapine vs. efavirenz, therapy duration, or subtype, tenofovir was more likely than zidovudine to retain antiviral activity following first-line d4T therapy.

    View details for DOI 10.1093/infdis/jit114

    View details for PubMedID 23687292

    View details for PubMedCentralID PMC3657117

  • In vitro HIV-1 evolution in response to triple reverse transcriptase inhibitors & in silico phenotypic analysis. PloS one Rath, B. A., Yousef, K. P., Katzenstein, D. K., Shafer, R. W., Schtte, C., von Kleist, M., Merigan, T. C. 2013; 8 (4)

    Abstract

    Effectiveness of ART regimens strongly depends upon complex interactions between the selective pressure of drugs and the evolution of mutations that allow or restrict drug resistance.Four clinical isolates from NRTI-exposed, NNRTI-naive subjects were passaged in increasing concentrations of NVP in combination with 1 M 3 TC and 2 M ADV to assess selective pressures of multi-drug treatment. A novel parameter inference procedure, based on a stochastic viral growth model, was used to estimate phenotypic resistance and fitness from in vitro combination passage experiments.Newly developed mathematical methods estimated key phenotypic parameters of mutations arising through selective pressure exerted by 3 TC and NVP. Concentrations of 1 M 3 TC maintained the M184V mutation, which was associated with intrinsic fitness deficits. Increasing NVP concentrations selected major NNRTI resistance mutations. The evolutionary pathway of NVP resistance was highly dependent on the viral genetic background, epistasis as well as stochasticity. Parameter estimation indicated that the previously unrecognized mutation L228Q was associated with NVP resistance in some isolates.Serial passage of viruses in the presence of multiple drugs may resemble the selection of mutations observed among treated individuals and populations in vivo and indicate evolutionary preferences and restrictions. Phenotypic resistance estimated here "in silico" from in vitro passage experiments agreed well with previous knowledge, suggesting that the unique combination of "wet-" and "dry-lab" experimentation may improve our understanding of HIV-1 resistance evolution in the future.

    View details for DOI 10.1371/journal.pone.0061102

    View details for PubMedID 23613794

    View details for PubMedCentralID PMC3629221

  • In Vitro HIV-1 Evolution in Response to Triple Reverse Transcriptase Inhibitors & In Silico Phenotypic Analysis. PloS one Rath, B. A., Yousef, K. P., Katzenstein, D. K., Shafer, R. W., Schtte, C., von Kleist, M., Merigan, T. C. 2013; 8 (4)

    View details for DOI 10.1371/journal.pone.0061102

    View details for PubMedID 23613794

  • Prototypical Recombinant Multi-Protease Inhibitor Resistant Infectious Molecular Clones of Human Immunodeficiency Virus Type-1. Antimicrobial agents and chemotherapy Varghese, V., Mitsuya, Y., Fessel, W. J., Liu, T. F., Melikian, G. L., Katzenstein, D. A., Schiffer, C. A., Holmes, S. P., Shafer, R. W. 2013

    Abstract

    The many genetic manifestations of HIV-1 protease inhibitor (PI) resistance present challenges to research into the mechanisms of PI-resistance and the assessment of new PIs. To address these challenges, we created a panel of recombinant multi-PI resistant infectious molecular clones designed to represent the spectrum of clinically relevant multi-PI resistant viruses. To assess the representativeness of this panel, we examined the sequences of the panel's viruses in the context of a correlation network of PI-resistance amino acid substitutions in sequences from more than 10,000 patients. The panel of recombinant infectious molecular clones comprised 29 of 41 study-defined PI-resistance amino acid substitutions and 23 of the 27 tightest amino acid substitution clusters. Based on their phenotypic properties, the clones were classified into four groups with increasing cross-resistance to the PIs most commonly used for salvage therapy: lopinavir (LPV), tipranavir (TPV), and darunavir (DRV). The panel of recombinant infectious molecular clones has been made available without restriction through the NIH AIDS Research and Reference Reagent Program. The public availability of the panel makes it possible to compare the inhibitory activity of different PIs with one another. The diversity of the panel and the high-level PI resistance of its clones suggest that investigational PIs active against the clones in this panel will retain antiviral activity against most, if not all clinically relevant PI-resistant viruses.

    View details for PubMedID 23796938

  • HIV-1 Amino Acid Changes Among Participants With Virologic Failure: Associations With First-line Efavirenz or Atazanavir Plus Ritonavir and Disease Status JOURNAL OF INFECTIOUS DISEASES Mollan, K., Daar, E. S., Sax, P. E., Balamane, M., Collier, A. C., Fischl, M. A., Lalama, C. M., Bosch, R. J., Tierney, C., Katzenstein, D. 2012; 206 (12): 1920-1930

    Abstract

    Although specific human immunodeficiency virus type 1 (HIV-1) drug resistance mutations are well studied, little is known about cumulative amino acid changes, or how regimen and participant characteristics influence these changes.In the AIDS Clinical Trials Group randomized study A5202 of treatment-naive HIV-infected participants, cumulative HIV-1 amino acid changes from pretreatment to virologic failure were evaluated in protease and reverse transcriptase (RT) gene sequences.Among 265 participants with virologic failure, those assigned atazanavir plus ritonavir (ATV/r) did not have significantly more protease changes compared with those assigned efavirenz (EFV) (P ? .13). In contrast, participants with virologic failure assigned EFV had more RT changes, including and excluding known resistance codons (P < .001). At pretreatment, lower CD4 cell count, major resistance, more amino acid mixtures (all P < .001), hepatitis C antibody negativity (P = .05), and black race/ethnicity (P = .02) were associated with more HIV-1 amino acid changes.Virologic failure following EFV-containing treatment was associated with more HIV-1 amino acid changes compared to failure of ATV/r-containing treatment. Furthermore, we show that non-drug resistance mutations occurred more frequently among those failing EFV, the clinical relevance of which warrants further investigation. Pretreatment immunologic status may play a role in viral evolution during treatment, as evidenced by increased amino acid changes among those with lower pretreatment CD4 count.NCT00118898.

    View details for DOI 10.1093/infdis/jis613

    View details for Web of Science ID 000311667400016

    View details for PubMedID 23148287

    View details for PubMedCentralID PMC3502379

  • Are subtype differences important in HIV drug resistance? CURRENT OPINION IN VIROLOGY Lessells, R. J., Katzenstein, D. K., de Oliveira, T. 2012; 2 (5): 636-643

    Abstract

    The diversity of human immunodeficiency virus type 1 (HIV-1) has given rise to multiple subtypes and recombinant strains. The majority of research into antiretroviral agents and drug resistance has been performed on subtype B viruses, yet non-subtype B strains are responsible for 90% of global infections. Although it seems that combination antiretroviral regimens are effective against all HIV-1 subtypes, there is emerging evidence of subtype differences in drug resistance, relevant to antiretroviral strategies in different parts of the world. For this purpose, extensive sampling of HIV genetic diversity, curation and analyses are required to inform antiretroviral strategies in different parts of the world.

    View details for DOI 10.1016/j.coviro.2012.08.006

    View details for Web of Science ID 000312228400018

    View details for PubMedID 23006584

    View details for PubMedCentralID PMC3951383

  • Panel of Prototypical Recombinant Infectious Molecular Clones Resistant to Nevirapine, Efavirenz, Etravirine, and Rilpivirine ANTIMICROBIAL AGENTS AND CHEMOTHERAPY Balamane, M., Varghese, V., Melikian, G. L., Fessel, W. J., Katzenstein, D. A., Shafer, R. W. 2012; 56 (8): 4522-4524

    Abstract

    We created a panel of 10 representative multi-nonnucleoside reverse transcriptase inhibitor (NNRTI)-resistant recombinant infectious molecular HIV-1 clones to assist researchers studying NNRTI resistance or developing novel NNRTIs. The cloned viruses contain most of the major NNRTI resistance mutations and most of the significantly associated mutation pairs that we identified in two network analyses. Each virus in the panel has intermediate- or high-level resistance to all or three of the four most commonly used NNRTIs.

    View details for DOI 10.1128/AAC.00648-12

    View details for Web of Science ID 000306826300069

    View details for PubMedID 22664973

    View details for PubMedCentralID PMC3421573

  • Lopinavir/ritonavir monotherapy after virologic failure of first-line antiretroviral therapy in resource-limited settings AIDS Bartlett, J. A., Ribaudo, H. J., Wallis, C. L., Aga, E., Katzenstein, D. A., Stevens, W. S., Norton, M. R., Klingman, K. L., Hosseinipour, M. C., Crump, J. A., Supparatpinyo, K., Badal-Faesen, S., Kallungal, B. A., Kumarasamy, N. 2012; 26 (11): 1345-1353

    Abstract

    To evaluate virologic response rates of lopinavir/ritonavir (LPV/r) monotherapy as second-line antiretroviral treatment (ART) among adults in resource-limited settings (RLSs).An open-label pilot study of LPV/r monotherapy in participants on first-line nonnucleoside reverse transcriptase inhibitor three-drug combination ART with plasma HIV-1 RNA 1000-200?000? copies/ml.Participants were recruited from five sites in Africa and Asia within the AIDS Clinical Trials Group (ACTG) network. All participants received LPV/r 400/100 ?mg twice daily. The primary endpoint was remaining on LPV/r monotherapy without virologic failure at week 24. Participants with virologic failure were offered addition of emtricitabine and tenofovir (FTC/TDF) to LPV/r.Mutations associated with drug resistance were encountered in nearly all individuals screened for the study. One hundred and twenty-three participants were enrolled, and 122 completed 24 weeks on study. A high proportion remained on LPV/r monotherapy without virologic failure at 24 weeks (87%). Archived samples with HIV-1 RNA levels less than 400 ?copies/ml at week 24 (n=102) underwent ultrasensitive assay. Of these individuals, 62 had levels less than 40? copies/ml and 30 had levels 40-200 ?copies/ml. Fifteen individuals experienced virologic failure, among whom 11 had resistance assessed and two had emergent protease inhibitor mutations. Thirteen individuals with virologic failure added FTC/TDF and one individual added FTC/TDF without virologic failure. At study week 48, 11 of 14 adding FTC/TDF had HIV-1 RNA levels less than 400? copies/ml.In this pilot study conducted in diverse RLS, LPV/r monotherapy as second-line ART demonstrated promising activity.

    View details for DOI 10.1097/QAD.0b013e328353b066

    View details for Web of Science ID 000306130700004

    View details for PubMedID 22441252

    View details for PubMedCentralID PMC3443745

  • Primary Drug Resistance in South Africa: Data from 10 Years of Surveys AIDS RESEARCH AND HUMAN RETROVIRUSES Manasa, J., Katzenstein, D., Cassol, S., Newell, M., de Oliveira, T. 2012; 28 (6): 558-565

    Abstract

    HIV-1 transmitted drug resistance (TDR) could reverse the gains of antiretroviral rollout. To ensure that current first-line therapies remain effective, TDR levels in recently infected treatment-naive patients need to be monitored. A literature review and data mining exercise was carried out to determine the temporal trends in TDR in South Africa. In addition, 72 sequences from seroconvertors identified from Africa Centre's 2010 HIV surveillance round were also examined for TDR. Publicly available data on TDR were retrieved from GenBank, curated in RegaDB, and analyzed using the Calibrated Population Resistance Program. There was no evidence of TDR from the 2010 rural KwaZulu Natal samples. Ten datasets with a total of 1618 sequences collected between 2000 and 2010 were pooled to provide a temporal analysis of TDR. The year with the highest TDR rate was 2002 [6.67%, 95% confidence interval (CI): 3.09-13.79%; n=6/90]. After 2002, TDR levels returned to <5% (WHO low-level threshold) and showed no statistically significant increase in the interval between 2002 and 2010. The most common mutations were associated with NNRTI resistance, K103N, followed by Y181C and Y188C/L. Five sequences had multiple resistance mutations associated with NNRTI resistance. There is no evidence of TDR in rural KwaZulu-Natal. TDR levels in South Africa have remained low following a downward trend since 2003. Continuous vigilance in monitoring of TDR is needed as more patients are initiated and maintained onto antiretroviral therapy.

    View details for DOI 10.1089/aid.2011.0284

    View details for Web of Science ID 000304780100005

    View details for PubMedID 22251009

    View details for PubMedCentralID PMC3358100

  • Global analysis of sequence diversity within HIV-1 subtypes across geographic regions FUTURE VIROLOGY Huang, A., Hogan, J. W., Istrail, S., DeLong, A., Katzenstein, D. A., Kantor, R. 2012; 7 (5): 505-517

    View details for DOI 10.2217/FVL.12.37

    View details for Web of Science ID 000303552900013

  • Viremia and HIV-1 Drug Resistance Mutations Among Patients Receiving Second-Line Highly Active Antiretroviral Therapy in Chennai, Southern India CLINICAL INFECTIOUS DISEASES Saravanan, S., Vidya, M., Balakrishnan, P., Kantor, R., Solomon, S. S., Katzenstein, D., Kumarasamy, N., Yeptomi, T., Sivamalar, S., Rifkin, S., Mayer, K. H., Solomon, S. 2012; 54 (7): 995-1000

    Abstract

    A cross-sectional study among individuals receiving second-line antiretroviral treatment was conducted to report on the level of detectable viremia and the types of drug resistance mutations among those with detectable human immunodeficiency virus (HIV) type 1 plasma viral loads (PVLs).PVLs were measured using Abbott m2000rt real-time polymerase chain reaction, and genotyping was performed with the ViroSeq genotyping system, version 2.0, and ViroSeq analysis software, version 2.8.Of 107 patient plasma specimens consecutively analyzed, 30 (28%) had undetectable PVLs (<150 copies/mL), and 77 (72%) were viremic with a median PVL of 5450 copies/mL (interquartile range, 169-1 997 967). Sequencing was done for 107 samples with PVLs >2000 copies/mL: 33 patients (73%) had 1 of the protease (PR) inhibitor mutations; 41 (91%) had nucleoside reverse-transcriptase inhibitor (NRTI) mutations; 33 (73%) had non-NRTI (NNRTI) mutations; and 30 (66.7%) had both NRTI and NNRTI mutations. Triple-class resistance to NRTIs, NNRTIs, and PR inhibitors was observed in 24 (53%) patients. Based on the mutational profiles observed, all 45 sequences were susceptible to darunavir and tipranavir, whereas 47% showed resistance to lopinavir, 58% showed resistance to atazanavir, and >60% showed resistance to saquinavir, indinavir, nelfinavir, and fosamprenavir.The results of the study showed that the majority of patients receiving second-line antiretroviral therapy started to accumulate PR resistance mutations, and the mutation profiles suggest that darunavir might be the drug of choice for third-line regimens in India.

    View details for DOI 10.1093/cid/cir967

    View details for Web of Science ID 000301296200024

    View details for PubMedID 22323567

    View details for PubMedCentralID PMC3571716

  • Zidovudine (AZT) Monotherapy Selects for the A360V Mutation in the Connection Domain of HIV-1 Reverse Transcriptase PLOS ONE Brehm, J. H., Scott, Y., Koontz, D. L., Perry, S., Hammer, S., Katzenstein, D., Mellors, J. W., Sluis-Cremer, N. 2012; 7 (2)

    Abstract

    We previously demonstrated in vitro that zidovudine (AZT) selects for A371V in the connection domain and Q509L in ribonuclease H (RNase H) domain of HIV-1 reverse transcriptase (RT) which, together with the thymidine analog mutations D67N, K70R and T215F, confer greater than 100-fold AZT resistance. The goal of the current study was to determine whether AZT monotherapy in HIV-1 infected patients also selects the A371V, Q509L or other mutations in the C-terminal domains of HIV-1 RT.Full-length RT sequences in plasma obtained pre- and post-therapy were compared in 23 participants who received AZT monotherapy from the AIDS Clinical Trials Group study 175. Five of the 23 participants reached a primary study endpoint. Mutations significantly associated with AZT monotherapy included K70R (p?=?0.003) and T215Y (p?=?0.013) in the polymerase domain of HIV-1 RT, and A360V (p?=?0.041) in the connection domain of HIV-1 RT. HIV-1 drug susceptibility assays demonstrated that A360V, either alone or in combination with thymidine analog mutations, decreased AZT susceptibility in recombinant viruses containing participant-derived full-length RT sequences or site-directed mutant RT. Biochemical studies revealed that A360V enhances the AZT-monophosphate excision activity of purified RT by significantly decreasing the frequency of secondary RNase H cleavage events that reduce the RNA/DNA duplex length and promote template/primer dissociation.The A360V mutation in the connection domain of RT was selected in HIV-infected individuals that received AZT monotherapy and contributed to AZT resistance.

    View details for DOI 10.1371/journal.pone.0031558

    View details for Web of Science ID 000302873700071

    View details for PubMedID 22363673

    View details for PubMedCentralID PMC3283647

  • Reverse Transcriptase Substitution at Codons 208 and 228 Among Treatment-Experienced HIV-1 Subtype-C-Infected Indian Patients Is Strongly Associated With Thymidine Analogue Mutations JAIDS-JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Saravanan, S., Madhavan, V., Solomon, S. S., Kantor, R., Katzenstein, D., Sivamalar, S., Kumarasamy, N., Smith, D. M., Mayer, K. H., Solomon, S., Balakrishnan, P. 2012; 59 (2): E26-E27

    View details for DOI 10.1097/QAI.0b013e31823e2d2b

    View details for Web of Science ID 000299789600004

    View details for PubMedID 22245718

    View details for PubMedCentralID PMC3259528

  • Comparing Peripheral Blood Mononuclear Cell DNA and Circulating Plasma viral RNA pol Genotypes of Subtype C HIV-1. Journal of AIDS & clinical research Banks, L., Gholamin, S., White, E., Zijenah, L., Katzenstein, D. A. 2012; 3 (2): 141-147

    Abstract

    INTRODUCTION: Drug resistance mutations (DRM) in viral RNA are important in defining to provide effective antiretroviral therapy (ART) in HIV-1 infected patients. Detection of DRM in peripheral blood mononuclear cell (PBMC) DNA is another source of information, although the clinical significance of DRMs in proviral DNA is less clear. MATERIALS AND METHODS: From 25 patients receiving ART at a center in Zimbabwe, 32 blood samples were collected. Dideoxy-sequencing of gag-pol identified subtype and resistance mutations from plasma viral RNA and proviral DNA. Drug resistance was estimated using the calibrated population resistance tool on www.hivdb.stanford.edu database. Numerical resistance scores were calculated for all antiretroviral drugs and for the subjects' reported regimen. Phylogenetic analysis as maximum likelihood was performed to determine the evolutionary distance between sequences. RESULTS: Of the 25 patients, 4 patients (2 of which had given 2 blood samples) were not known to be on ART (NA) and had exclusively wild-type virus, 17 had received Protease inhibitors (PI), 18, non-nucleoside reverse transcriptase inhibitors (NNRTI) and 19, two or more nucleoside reverse transcriptase inhibitors (NRTI). Of the 17 with history of PI, 10 had PI mutations, 5 had minor differences between mutations in RNA and DNA. Eighteen samples had NNRTI mutations, six of which demonstrated some discordance between DNA and RNA mutations. Although NRTI resistance mutations were frequently different between analyses, mutations resulted in very similar estimated phenotypes as measured by resistance scores. The numerical resistance scores from RNA and DNA for PIs differed between 2/10, for NNRTIs between 8/18, and for NRTIs between 17/32 pairs. When calculated resistance scores were collapsed, 3 pairs showed discordance between RNA and DNA for at least one PI, 6 were discordant for at least one NNRTI and 11 for at least one NRTI. Regarding phylogenetic evolutionary analysis, all RNA and DNA sequence pairs clustered closely in a maximum likelihood tree. CONCLUSION: PBMC DNA could be useful for testing drug resistance in conjunction with plasma RNA where the results of each yielded complementary information about drug resistance. Identification of DRM, archived in proviral DNA, could be used to provide for sustainable public health surveillance among subtype C infected patients.

    View details for PubMedID 23019537

  • HIV disclosure patterns, predictors, and psychosocial correlates among HIV positive women in Zimbabwe AIDS CARE-PSYCHOLOGICAL AND SOCIO-MEDICAL ASPECTS OF AIDS/HIV Patel, R., Ratner, J., Gore-Felton, C., Kadzirange, G., Woelk, G., Katzenstein, D. 2012; 24 (3): 358-368

    Abstract

    Disclosure of positive HIV status in Sub-Saharan Africa has been associated with safer sexual practices and better antiretroviral therapy (ART) adherence, but associations with psychosocial function are unclear. We examined patterns and psychosocial correlates of disclosure in a Zimbabwean community. Two hundred HIV positive women at different stages of initiating ART participated in a cross-sectional study examining actual disclosures, disclosure beliefs, perceived stigma, self-esteem, depression, and quality of life. Ninety-seven percent of the women disclosed to at least one person, 78% disclosed to their current husband/partner, with an average disclosure of four persons per woman. The majority (85-98%) of disclosures occurred in a positive manner and 72-95% of the individuals reacted positively. Factors significantly correlated with HIV disclosure to partners included being married, later age at menses, longer duration of HIV since diagnosis, being on ART, being more symptomatic at baseline, ever having used condoms, and greater number of partners in the last year. In multivariate analysis, being married and age at menses predicted disclosure to partners. Positive disclosure beliefs, but not the total number of disclosures, significantly correlated with lower perceived stigma (? = 0.44 for personalized subscale and ? = 0.51 for public subscale, both p<0.0001), higher self-esteem (? = 0.15, p=0.04), and fewer depressive symptoms (? = -0.14, p=0.05). In conclusion, disclosure of positive HIV status among Zimbabwean women is common and is frequently met with positive reactions. Moreover, positive disclosure beliefs correlate significantly with psychosocial measures, including lower perceived stigma, higher self-esteem, and lower depression.

    View details for DOI 10.1080/09540121.2011.608786

    View details for Web of Science ID 000301532700011

    View details for PubMedID 21902570

    View details for PubMedCentralID PMC3243809

  • Abacavir/Lamivudine Versus Tenofovir DF/Emtricitabine as Part of Combination Regimens for Initial Treatment of HIV: Final Results JOURNAL OF INFECTIOUS DISEASES Sax, P. E., Tierney, C., Collier, A. C., Daar, E. S., Mollan, K., Budhathoki, C., Godfrey, C., Jahed, N. C., Myers, L., Katzenstein, D., Farajallah, A., Rooney, J. F., Ha, B., Woodward, W. C., Feinberg, J., Tashima, K., Murphy, R. L., Fischl, M. A. 2011; 204 (8): 1191-1201

    Abstract

    AIDS Clinical Trials Group A5202 compared blinded abacavir/lamivudine (ABC/3TC) to tenofovir DF/emtricitabine (TDF/FTC) with efavirenz (EFV) or atazanavir/ritonavir (ATV/r) in human immunodeficiency virus (HIV)-infected treatment-naive patients, stratified by screening HIV RNA (< or ? 10(5) copies/mL). Due to higher virologic failure with ABC/3TC in the high HIV RNA stratum, blinded treatment was stopped in this group, but study follow-up continued for all patients.Primary endpoints were times to virologic failure, regimen modification, and safety event.In the low HIV RNA stratum, time to virologic failure was similar for ABC/3TC vs TDF/FTC with ATV/r (hazard ratio [HR] 1.25, 95% confidence interval [CI] 0.76, 2.05) or EFV (HR 1.23, 95% CI 0.77, 1.96), with significantly shorter times to regimen modification for ABC/3TC with EFV or ATV/r and to safety events with EFV. Prior to stopping blinded treatment in the high stratum, higher virologic failure rates were seen with ABC/3TC with EFV (HR 2.46, 95% CI 1.20, 5.05) or ATV/r (HR 2.22, 95% CI 1.19, 4.14).In the low HIV RNA stratum, times to virologic failure for ABC/3TC or TDF/FTC were not different with EFV or ATV/r. In the high stratum, virologic failure rate was significantly higher for ABC/3TC than for TDF/FTC when given with either EFV or ATV/r.

    View details for DOI 10.1093/infdis/jir505

    View details for Web of Science ID 000294970100008

    View details for PubMedID 21917892

    View details for PubMedCentralID PMC3173503

  • Placental Malaria and Mother-to-Child Transmission of Human Immunodeficiency Virus-1 in Rural Rwanda AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE Bulterys, P. L., Chao, A., Dalai, S. C., Zink, M. C., Dushimimana, A., Katzenstein, D., Saah, A. J., Bulterys, M. 2011; 85 (2): 202-206

    Abstract

    We conducted a nested case-control study of placental malaria (PM) and mother-to-child transmission (MTCT) of human immunodeficiency virus-1 (HIV-1) within a prospective cohort of 627 mother-infant pairs followed from October 1989 until April 1994 in rural Rwanda. Sixty stored placentas were examined for PM and other placental pathology, comparing 20 HIV-infected mother-infant (perinatal transmitter) pairs, 20 HIV-uninfected pairs, and 20 HIV-infected mothers who did not transmit to their infant perinatally. Of 60 placentas examined, 45% showed evidence of PM. Placental malaria was associated with increased risk of MTCT of HIV-1 (adjusted odds ratio [aOR] = 6.3; 95% confidence interval [CI] = 1.4-29.1), especially among primigravidae (aOR = 12.0; 95% CI = 1.0-150; P < 0.05). Before antiretroviral therapy or prophylaxis, PM was associated with early infant HIV infection among rural Rwandan women living in a hyper-endemic malaria region. Primigravidae, among whom malaria tends to be most severe, may be at higher risk.

    View details for DOI 10.4269/ajtmh.2011.10-0589

    View details for Web of Science ID 000293613000004

    View details for PubMedID 21813835

    View details for PubMedCentralID PMC3144813

  • Surveillance of Transmitted Antiretroviral Drug Resistance among HIV-1 Infected Women Attending Antenatal Clinics in Chitungwiza, Zimbabwe PLOS ONE Tshabalala, M., Manasa, J., Zijenah, L. S., Rusakaniko, S., Kadzirange, G., Mucheche, M., Kassaye, S., Johnston, E., Katzenstein, D. 2011; 6 (6)

    Abstract

    The rapid scale-up of highly active antiretroviral therapy (HAART) and use of single dose Nevirapine (SD NVP) for prevention of mother-to-child transmission (pMTCT) have raised fears about the emergence of resistance to the first line antiretroviral drug regimens. A cross-sectional study was conducted to determine the prevalence of primary drug resistance (PDR) in a cohort of young (<25 yrs) HAART-nave HIV pregnant women attending antenatal clinics in Chitungwiza, Zimbabwe. Whole blood was collected in EDTA for CD4 counts, viral load, serological estimation of duration of infection using the BED Calypte assay and genotyping for drug resistance. Four hundred and seventy-one women, mean age 21 years; SD: 2.1 were enrolled into the study between 2006 and 2007. Their median CD4 count was 371cells/L; IQR: 255-511 cells/L. Two hundred and thirty-six samples were genotyped for drug resistance. Based on the BED assay, 27% were recently infected (RI) whilst 73% had long-term infection (LTI). Median CD4 count was higher (p<0.05) in RI than in women with LTI. Only 2 women had drug resistance mutations; protease I85V and reverse transcriptase Y181C. Prevalence of PDR in Chitungwiza, 4 years after commencement of the national ART program remained below WHO threshold limit (5%). Frequency of recent infection BED testing is consistent with high HIV acquisition during pregnancy. With the scale-up of long-term ART programs, maintenance of proper prescribing practices, continuous monitoring of patients and reinforcement of adherence may prevent the acquisition and transmission of PDR.

    View details for DOI 10.1371/journal.pone.0021241

    View details for Web of Science ID 000291734100073

    View details for PubMedID 21698125

    View details for PubMedCentralID PMC3116901

  • The Incidence and Correlates of Symptomatic and Asymptomatic Chlamydia trachomatis and Neisseria gonorrhoeae Infections in Selected Populations in Five Countries SEXUALLY TRANSMITTED DISEASES Detels, R., Green, A. M., Klausner, J. D., Katzenstein, D., Gaydos, C., Handsfield, H. H., Pequegnat, W., Mayer, K., Hartwell, T. D., Quinn, T. C. 2011; 38 (6): 503-509

    Abstract

    Asymptomatic Chlamydia trachomatis (chlamydia) and Neisseria gonorrhoeae (gonorrhea) infections pose diagnostic and control problems in developing countries.Participants in China, India, Peru, Russia, and Zimbabwe were screened for C. trachomatis and N. gonorrhoeae infections and symptoms.A total of 18,014 participants were evaluated at baseline, 15,054 at 12 months, and 14,243 at 24 months. The incidence of chlamydia in men was 2.0 per 100 person years both from baseline to 12 months and from 12 to 24 months, and in women, 4.6 from baseline to 12 months and 3.6 from 12 to 24 months; a range of 31.2% to 100% reported no symptoms across the 5 countries. The incidence of gonorrhea in men was 0.3 per 100 person years both from baseline to 12 months and from 12 to 24 months, and in women, 1.4 from baseline to 12 months and 1.1 from 12 to 24 months; a range of 66.7% to 100% reported no symptoms. Being female, aged 18 to 24 years, and having more than 1 partner were associated with both the infections. In addition, being divorced, separated, or widowed was associated with gonorrhea. Being male, having 6+ years of education, and reporting only 1 partner were associated with having no symptoms among those infected with chlamydia. No variables correlated with asymptomatic gonorrhea among those infected.A high prevalence and incidence of asymptomatic sexually transmitted infections was identified among men and women in a wide variety of settings. More effective programs are needed to identify and treat chlamydia and gonorrhea infections, especially among women, young adults, those with multiple partners, those repeatedly infected, and particularly those at risk without symptoms. The risk of transmission from persons with no symptoms requires further study.

    View details for DOI 10.1097/OLQ.0b013e318206c288

    View details for Web of Science ID 000290561200008

    View details for PubMedID 22256336

    View details for PubMedCentralID PMC3408314

  • Atazanavir Plus Ritonavir or Efavirenz as Part of a 3-Drug Regimen for Initial Treatment of HIV-1 ANNALS OF INTERNAL MEDICINE Daar, E. S., Tierney, C., Fischl, M. A., Sax, P. E., Mollan, K., Budhathoki, C., Godfrey, C., Jahed, N. C., Myers, L., Katzenstein, D., Farajallah, A., Rooney, J. F., Pappa, K. A., Woodward, W. C., Patterson, K., Bolivar, H., Benson, C. A., Collier, A. C. 2011; 154 (7)

    Abstract

    Limited data compare once-daily options for initial therapy for HIV-1.To compare time to virologic failure; first grade-3 or -4 sign, symptom, or laboratory abnormality (safety); and change or discontinuation of regimen (tolerability) for atazanavir plus ritonavir with efavirenz-containing initial therapy for HIV-1.A randomized equivalence trial accrued from September 2005 to November 2007, with median follow-up of 138 weeks. Regimens were assigned by using a central computer, stratified by screening HIV-1 RNA level less than 100 000 copies/mL or 100 000 copies/mL or greater; blinding was known only to the site pharmacist. (ClinicalTrials.gov registration number: NCT00118898)59 AIDS Clinical Trials Group sites in the United States and Puerto Rico.Antiretroviral-naive patients.Open-label atazanavir plus ritonavir or efavirenz, each given with with placebo-controlled abacavir-lamivudine or tenofovir disoproxil fumarate (DF)-emtricitabine.Primary outcomes were time to virologic failure, safety, and tolerability events. Secondary end points included proportion of patients with HIV-1 RNA level less than 50 copies/mL, emergence of drug resistance, changes in CD4 cell counts, calculated creatinine clearance, and lipid levels.463 eligible patients were randomly assigned to receive atazanavir plus ritonavir and 465 were assigned to receive efavirenz, both with abacavir-lamivudine; 322 (70%) and 324 (70%), respectively, completed follow-up. The respective numbers of participants in each group who received tenofovir DF-emtricitabine were 465 and 464; 342 (74%) and 343 (74%) completed follow-up. Primary efficacy was similar in the group that received atazanavir plus ritonavir and and the group that received efavirenz and did not differ according to whether abacavir-lamivudine or tenofovir DF-emtricitabine was also given. Hazard ratios for time to virologic failure were 1.13 (95% CI, 0.82 to 1.56) and 1.01 (CI, 0.70 to 1.46), respectively, although CIs did not meet prespecified criteria for equivalence. The time to safety (P = 0.048) and tolerability (P < 0.001) events was longer in persons given atazanavir plus ritonavir than in those given efavirenz with abacavir-lamivudine but not with tenofovir DF-emtricitabine.Neither HLA-B*5701 nor resistance testing was the standard of care when A5202 enrolled patients. The third drugs, atazanavir plus ritonavir and efavirenz, were open-label; the nucleoside reverse transcriptase inhibitors were prematurely unblinded in the high viral load stratum; and 32% of patients modified or discontinued treatment with their third drug.Atazanavir plus ritonavir and efavirenz have similar antiviral activity when used with abacavir-lamivudine or tenofovir DF-emtricitabine.National Institutes of Health.

    View details for DOI 10.1059/0003-4819-154-7-201104050-00316

    View details for Web of Science ID 000289078700001

    View details for PubMedID 21320923

  • Adherence to Drug-Refill Is a Useful Early Warning Indicator of Virologic and Immunologic Failure among HIV Patients on First-Line ART in South Africa PLOS ONE El-Khatib, Z., Katzenstein, D., Marrone, G., Laher, F., Mohapi, L., Petzold, M., Morris, L., Ekstrom, A. M. 2011; 6 (3)

    Abstract

    Affordable strategies to prevent treatment failure on first-line regimens among HIV patients are essential for the long-term success of antiretroviral therapy (ART) in sub-Saharan Africa. WHO recommends using routinely collected data such as adherence to drug-refill visits as early warning indicators. We examined the association between adherence to drug-refill visits and long-term virologic and immunologic failure among non-nucleoside reverse transcriptase inhibitor (NNRTI) recipients in South Africa.In 2008, 456 patients on NNRTI-based ART for a median of 44 months (range 12-99 months; 1,510 person-years) were enrolled in a retrospective cohort study in Soweto. Charts were reviewed for clinical characteristics before and during ART. Multivariable logistic regression and Kaplan-Meier survival analysis assessed associations with virologic (two repeated VL>50 copies/ml) and immunologic failure (as defined by WHO).After a median of 15 months on ART, 19% (n?=?88) and 19% (n?=?87) had failed virologically and immunologically respectively. A cumulative adherence of <95% to drug-refill visits was significantly associated with both virologic and immunologic failure (p<0.01). In the final multivariable model, risk factors for virologic failure were incomplete adherence (OR 2.8, 95%CI 1.2-6.7), and previous exposure to single-dose nevirapine or any other antiretrovirals (adj. OR 2.1, 95%CI 1.2-3.9), adjusted for age and sex. In Kaplan-Meier analysis, the virologic failure rate by month 48 was 19% vs. 37% among adherent and non-adherent patients respectively (logrank p value?=?0.02).One in five failed virologically after a median of 15 months on ART. Adherence to drug-refill visits works as an early warning indicator for both virologic and immunologic failure.

    View details for DOI 10.1371/journal.pone.0017518

    View details for Web of Science ID 000288170900024

    View details for PubMedID 21408071

    View details for PubMedCentralID PMC3052314

  • Lower CD4 Cell Count and Higher Virus Load, but Not Antiretroviral Drug Resistance, Are Associated with AIDS-Defining Events and Mortality: An ACTG Longitudinal Linked Randomized Trials (ALLRT) Analysis HIV CLINICAL TRIALS Swindells, S., Jiang, H., Mukherjee, A. L., Winters, M., Bosch, R. J., Katzenstein, D. 2011; 12 (2): 79-88

    View details for DOI 10.1310/hct1202-79

    View details for Web of Science ID 000289593500003

  • Adherence and virologic suppression during the first 24 weeks on antiretroviral therapy among women in Johannesburg, South Africa - a prospective cohort study BMC PUBLIC HEALTH El-Khatib, Z., Ekstrom, A. M., Coovadia, A., Abrams, E. J., Petzold, M., Katzenstein, D., Morris, L., Kuhn, L. 2011; 11

    Abstract

    Adherence is a necessary part of successful antiretroviral treatment (ART). We assessed risk factors for incomplete adherence among a cohort of HIV-infected women initiating ART and examined associations between adherence and virologic response to ART.A secondary data analysis was conducted on a cohort of 154 women initiating non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART at a single site in Johannesburg, South Africa. Ninety women had been enrolled in a prevention of mother-to-child transmission (pMTCT) program and were exposed to single-dose nevirapine (sdNVP) >18 months earlier. Women were interviewed pre-treatment and clinical, virologic and adherence data were collected during follow-up to 24 weeks. Incomplete adherence to ART was defined as returning >5% of medications, estimated by pill counts at scheduled visits. Multivariable logistic regression analysis and unadjusted odds ratio (95%CI) were performed, using STATA/SE (ver 10.1).About half of the women (53%) were <30 years of age, 63% had <11 years of schooling, 69% were unemployed and 37% lived in a shack. Seven percent of women had a viral load >400 copies/ml at 24 weeks and 37% had incomplete adherence at one or more visits. Incomplete adherence was associated with less education (p = 0.01) and lack of financial support from a partner (p = 0.02) after adjustment for confounders. Only when adherence levels dropped below 80% was there a significant association with viremia in the group overall (p = 0.02) although adherence <95% was associated with viremia in the sdNVP-exposed group (p = 0.03). The main reasons for incomplete adherence were being away from home, busy with other things and forgetting to take their medication.Virologic response to NNRTI-treatment in the cohort was excellent. However, women who received sdNVP were at greater risk of virologic failure when adherence was <95%. Women exposed to sdNVP, and those with less education and less social support may benefit from additional adherence counseling to ensure the long-term success of ART. More than 80% adherence may be sufficient to maintain virologic suppression on NNRTI-based regimens in the short-term, however complete adherence should be encouraged.

    View details for DOI 10.1186/1471-2458-11-88

    View details for Web of Science ID 000288069800001

    View details for PubMedID 21303548

    View details for PubMedCentralID PMC3046911

  • Operational challenges in delivering CD4 diagnostics in sub-Saharan Africa AIDS CARE-PSYCHOLOGICAL AND SOCIO-MEDICAL ASPECTS OF AIDS/HIV Thairu, L., KATZENSTEIN, D., Israelski, D. 2011; 23 (7): 814-821

    Abstract

    Access to reliable and low cost CD4 T-cell enumeration to stage illness and monitor anti-retroviral therapy remains elusive in resource-limited settings. We report challenges in delivering CD4 testing using the microcapillary Fluorescence-Activated Cell Sorter (FACS) methodology (Guava EasyCD4 instrument Guava Technologies, Hayward) in Burkina Faso and Zimbabwe. Resources, instruments, reagents, and training were provided to local laboratories within the existing infrastructure and data on CD4 were collected from routine laboratory testing. Challenges encountered included frequent instrument breakdown; poor manufacturer maintenance; difficulties in managing reagent stocks; high technician turnover; reliance on antiquated data management systems; redundant service provision; and lack of repeat testing in male HIV+ patients and in patients with higher CD4 counts after initial staging. While adopting newer, less expensive technologies such as fluorescent platforms and point of care tests can facilitate access to lower cost CD4 testing, our experience suggests that supply chain, corporate commitment to implementation, and community factors also require consideration.

    View details for DOI 10.1080/09540121.2010.541416

    View details for Web of Science ID 000299479300006

    View details for PubMedID 21400312

  • Drug resistance and tropism both are associated with AIDS-defining clinical events among nucleoside-treated subjects in ACTG175 20th International Workshop on HIV and Hepatitis Virus Drug Resistance and Curative Strategies Gholamin, S., Shin, H., Huang, H., White, E., Shulman, N., KATZENSTEIN, D. INT MEDICAL PRESS LTD. 2011: A58?A58
  • Reverse transcriptase (RT) and protease (PR) drug resistance mutations (DRM) and evolution at virological failure (VF) in AIDS Clinical Trials Group (ACTG) study A5202 20th International Workshop on HIV and Hepatitis Virus Drug Resistance and Curative Strategies Mollan, K. R., Daar, E. S., Tierney, C., Dalai, S., BALAMANE, M., Sax, P. E., Collier, A. C., Fischl, M. A., Lalama, C. M., Bosch, R. J., KATZENSTEIN, D. INT MEDICAL PRESS LTD. 2011: A124?A124
  • Viral Sequence Analysis from HIV-Infected Mothers and Infants: Molecular Evolution, Diversity, and Risk Factors for Mother-To-Child Transmission CLINICS IN PERINATOLOGY Bulterys, P. L., Dalai, S. C., Katzenstein, D. A. 2010; 37 (4): 739-?

    Abstract

    Great progress has been made in understanding the pathogenesis, treatment, and transmission of HIV and the factors influencing the risk of mother-to-child transmission (MTCT). Many questions regarding the molecular evolution and genetic diversity of HIV in the context of MTCT remain unanswered. Further research to identify the selective factors governing which variants are transmitted, how the compartmentalization of HIV in different cells and tissues contributes to transmission, and the influence of host immunity, viral diversity, and recombination on MTCT may provide insight into new prevention strategies and the development of an effective HIV vaccine.

    View details for DOI 10.1016/j.clp.2010.08.003

    View details for Web of Science ID 000285485400005

    View details for PubMedID 21078447

    View details for PubMedCentralID PMC3175486

  • Genetic Analyses of HIV-1 env Sequences Demonstrate Limited Compartmentalization in Breast Milk and Suggest Viral Replication within the Breast That Increases with Mastitis JOURNAL OF VIROLOGY Gantt, S., Carlsson, J., Heath, L., Bull, M. E., Shetty, A. K., Mutsvangwa, J., Musingwini, G., Woelk, G., Zijenah, L. S., Katzenstein, D. A., Mullins, J. I., Frenkel, L. M. 2010; 84 (20): 10812-10819

    Abstract

    The concentration of human immunodeficiency virus type 1 (HIV-1) is generally lower in breast milk than in blood. Mastitis, or inflammation of the breast, is associated with increased levels of milk HIV-1 and risk of mother-to-child transmission through breastfeeding. We hypothesized that mastitis facilitates the passage of HIV-1 from blood into milk or stimulates virus production within the breast. HIV-1 env sequences were generated from single amplicons obtained from breast milk and blood samples in a cross-sectional study. Viral compartmentalization was evaluated using several statistical methods, including the Slatkin and Maddison (SM) test. Mastitis was defined as an elevated milk sodium (Na(+)) concentration. The association between milk Na(+) and the pairwise genetic distance between milk and blood viral sequences was modeled using linear regression. HIV-1 was compartmentalized within milk by SM testing in 6/17 (35%) specimens obtained from 9 women, but all phylogenetic clades included viral sequences from milk and blood samples. Monotypic sequences were more prevalent in milk samples than in blood samples (22% versus 13%; P = 0.012), which accounted for half of the compartmentalization observed. Mastitis was not associated with compartmentalization by SM testing (P = 0.621), but Na(+) was correlated with greater genetic distance between milk and blood HIV-1 populations (P = 0.041). In conclusion, local production of HIV-1 within the breast is suggested by compartmentalization of virus and a higher prevalence of monotypic viruses in milk specimens. However, phylogenetic trees demonstrate extensive mixing of viruses between milk and blood specimens. HIV-1 replication in breast milk appears to increase with inflammation, contributing to higher milk viral loads during mastitis.

    View details for DOI 10.1128/JVI.00543-10

    View details for Web of Science ID 000282642600035

    View details for PubMedID 20660189

  • Viremia and drug resistance among HIV-1 patients on antiretroviral treatment: a cross-sectional study in Soweto, South Africa AIDS El-Khatib, Z., Ekstrom, A. M., Ledwaba, J., Mohapi, L., Laher, F., Karstaedt, A., Charalambous, S., Petzold, M., KatzensteinG, D., Morris, L. 2010; 24 (11): 1679-1687

    Abstract

    We assessed risk factors for viremia and drug resistance among long-term recipients of antiretroviral therapy (ART) in South Africa.In 2008, we conducted a cross-sectional study among patients receiving ART for 12 months or more. Genotypic resistance testing was performed on individuals with a viral load higher than 400 RNA copies/ml. Multiple logistic regression analysis was used to assess associations.Of 998 participants, 75% were women with a median age of 41 years. Most (64%) had been on treatment for more than 3 years. The prevalence of viremia was 14% (n = 139): 12% (102/883) on first-line [i.e. nonnucleoside reverse-transcriptase inhibitor (NNRTI)-based regimen] and 33% (37/115) on second-line (i.e. protease inhibitor (PI)-based regimen) ART. Of viremic patients, 78% had drug resistance mutations. For NRTIs, NNRTIs and PIs, the prevalence of mutations was 64, 81 and 2%, respectively, among first-line failures and 29, 54 and 6%, respectively, among second-line failures. M184V/I, K103N and V106A/M were the most common mutations. Significant risk factors associated with viremia on first-line regimen included concurrent tuberculosis treatment [odds ratio (OR) 6.4, 95% confidence interval (CI) 2.2-18.8, P < 0.01] and a recent history of poor adherence (OR 2.7, 1.3-5.6, P = 0.01). Among second-line failures, attending a public clinic (OR 4.6, 95% CI 1.8-11.3, P < 0.01) and not having a refrigerator at home (OR 6.7, 95% CI 1.2-37.5, P = 0.03) were risk factors for virological failure.Risk factors for viral failure were line regimen dependent. Second-line ART recipients had a higher rate of viremia, albeit with infrequent PI drug resistance mutations. Measures to maintain effective virologic suppression should include increased adherence counseling, attention to concomitant tuberculosis treatment and heat-stable formulations of second-line ART regimens.

    View details for DOI 10.1097/QAD.0b013e32833a097b

    View details for Web of Science ID 000279396600008

    View details for PubMedID 20453629

  • Nucleic Acid Template and the Risk of a PCR-Induced HIV-1 Drug Resistance Mutation PLOS ONE Varghese, V., Wang, E., Babrzadeh, F., Bachmann, M. H., Shahriar, R., Liu, T., Mappala, S. J., Gharizadeh, B., Fessel, W. J., Katzenstein, D., Kassaye, S., Shafer, R. W. 2010; 5 (6)

    Abstract

    The HIV-1 nucleoside RT inhibitor (NRTI)-resistance mutation, K65R confers intermediate to high-level resistance to the NRTIs abacavir, didanosine, emtricitabine, lamivudine, and tenofovir; and low-level resistance to stavudine. Several lines of evidence suggest that K65R is more common in HIV-1 subtype C than subtype B viruses.We performed ultra-deep pyrosequencing (UDPS) and clonal dideoxynucleotide sequencing of plasma virus samples to assess the prevalence of minority K65R variants in subtype B and C viruses from untreated individuals. Although UDPS of plasma samples from 18 subtype C and 27 subtype B viruses showed that a higher proportion of subtype C viruses contain K65R (1.04% vs. 0.25%; p<0.001), limiting dilution clonal sequencing failed to corroborate its presence in two of the samples in which K65R was present in >1.5% of UDPS reads. We therefore performed UDPS on clones and site-directed mutants containing subtype B- and C-specific patterns of silent mutations in the conserved KKK motif encompassing RT codons 64 to 66 and found that subtype-specific nucleotide differences were responsible for increased PCR-induced K65R mutation in subtype C viruses.This study shows that the RT KKK nucleotide template in subtype C viruses can lead to the spurious detection of K65R by highly sensitive PCR-dependent sequencing techniques. However, the study is also consistent with the subtype C nucleotide template being inherently responsible for increased polymerization-induced K65R mutations in vivo.

    View details for DOI 10.1371/journal.pone.0010992

    View details for Web of Science ID 000278465900010

    View details for PubMedID 20539818

    View details for PubMedCentralID PMC2881873

  • Fertility desires and condom use among HIV-positive women at an antiretroviral roll-out program in Zimbabwe. African journal of reproductive health McClellan, M. K., Patel, R., Kadzirange, G., Chipatod, T., Katzenstein, D. 2010; 14 (2): 27-35

    Abstract

    As access to anti-retroviral therapy (ART) increases in sub-Saharan Africa, fertility and contraception patterns are likely to change. Two hundred HIV-positive women at an ART roll-out site in Zimbabwe responded to a questionnaire on fertility desires and condom use. Ten women (5%) reported planning a pregnancy in the next year, comprising 0% of women not yet eligible for ART, 8.22% of women on the waitlist for ART, and 4.17% of women on ART. Younger age, fewer living children, and higher quality of life were individually associated with intended pregnancy in the next year; however in multivariate analysis only the association with higher quality of life remained significant. Reported ever use of condoms was relatively low (46.5%) and condom use varied by neither ART status nor by fertility desires. In conclusion, our data demonstrates fertility desires among HIV-positive women in Zimbabwe correlate with higher perceived quality of life.

    View details for PubMedID 21243916

  • Unusual five amino acid insert within subtype C HIV-1 envelope contributes to dual-tropism (X4R5) AIDS White, E. J., McColgan, B., Kassaye, S., Zijenah, L., Katzenstein, D. 2010; 24 (7): 1063-1064

    Abstract

    During the course of HIV infection, some HIV-1 viruses switch from using the CCR5 (R5) coreceptor to using CXCR4 (X4). Here, we describe two subtype C isolates from a Zimbabwean patient that switched from using R5 to using both R5 and X4 with an accompanying addition of five amino acids to the V3 loop region of envelope. The insert appears to be derived from the human genome rather than a duplication within HIV-1.

    View details for DOI 10.1097/QAD.0b013e328331f717

    View details for Web of Science ID 000276567500018

    View details for PubMedID 20299967

    View details for PubMedCentralID PMC3428204

  • A Controlled Trial of Initial Antiviral Regimens for HIV-1 Infection NEW ENGLAND JOURNAL OF MEDICINE Parienti, J. 2010; 362 (9): 854-854

    View details for Web of Science ID 000275108300023

    View details for PubMedID 20200393

  • Detection of HIV-1 in Saliva: Implications for Case-Identification, Clinical Monitoring and Surveillance for Drug Resistance. The open virology journal Balamane, M., Winters, M. A., Dalai, S. C., Freeman, A. H., Traves, M. W., Israelski, D. M., Katzenstein, D. A., Klausner, J. D. 2010; 4: 88-93

    Abstract

    Saliva tests that detect antibodies are used to diagnose HIV infection. The goal of this study was to determine whether saliva could be used for nucleic acid-based tests to measure HIV-1 virus load (VL) and detect drug resistance.69 HIV infected individuals provided 5-10 ml of saliva and blood samples. Viral RNA was isolated from saliva and dried blood spots using the Nuclisens extraction. Saliva VL was measured using a modified Amplicor assay, and genotyping was performed using an in-house RT-PCR/sequencing protocol. Plasma VLs were obtained from concurrently drawn clinical tests.Thirty-six of 47 (77%) plasma viremic patients had measurable saliva HIV-1 RNA. Paired plasma and saliva HIV RNA levels were significantly correlated (Spearman's correlation = .6532, p<.0001), but saliva VL was typically lower. Three of 22 patients with undetectable plasma VL (<50 copies/ml) had detectable saliva HIV RNA. Eleven of 30 patients with undetectable saliva RNA had detectable plasma HIV-1 RNA. Comparison of the protease and reverse transcriptase gene sequences from paired saliva and plasma of 20 patients showed less than 1% difference overall, and few resistance-related amino acid differencesMost patients with plasma virus >50 copies/mL had detectable saliva HIV RNA, and the genotypic data was highly concordant between saliva and plasma. In patients with high levels of plasma HIV RNA, saliva might be useful in identifying viremia and evaluating drug resistance.

    View details for DOI 10.2174/1874357901004010088

    View details for PubMedID 21673840

    View details for PubMedCentralID PMC3111737

  • Abacavir-Lamivudine versus Tenofovir-Emtricitabine for Initial HIV-1 Therapy NEW ENGLAND JOURNAL OF MEDICINE Sax, P. E., Tierney, C., Collier, A. C., Fischl, M. A., Mollan, K., Peeples, L., Godfrey, C., Jahed, N. C., Myers, L., Katzenstein, D., Farajallah, A., Rooney, J. F., Ha, B., Woodward, W. C., Koletar, S. L., Johnson, V. A., Geiseler, P. J., Daar, E. S. 2009; 361 (23): 2230-2240

    Abstract

    The use of fixed-dose combination nucleoside reverse-transcriptase inhibitors (NRTIs) with a nonnucleoside reverse-transcriptase inhibitor or a ritonavir-boosted protease inhibitor is recommended as initial therapy in patients with human immunodeficiency virus type 1 (HIV-1) infection, but which NRTI combination has greater efficacy and safety is not known.In a randomized, blinded equivalence study involving 1858 eligible patients, we compared four once-daily antiretroviral regimens as initial therapy for HIV-1 infection: abacavir-lamivudine or tenofovir disoproxil fumarate (DF)-emtricitabine plus efavirenz or ritonavir-boosted atazanavir. The primary efficacy end point was the time from randomization to virologic failure (defined as a confirmed HIV-1 RNA level > or = 1000 copies per milliliter at or after 16 weeks and before 24 weeks, or > or = 200 copies per milliliter at or after 24 weeks).A scheduled interim review by an independent data and safety monitoring board showed significant differences in virologic efficacy, according to the NRTI combination, among patients with screening HIV-1 RNA levels of 100,000 copies per milliliter or more. At a median follow-up of 60 weeks, among the 797 patients with screening HIV-1 RNA levels of 100,000 copies per milliliter or more, the time to virologic failure was significantly shorter in the abacavir-lamivudine group than in the tenofovir DF-emtricitabine group (hazard ratio, 2.33; 95% confidence interval, 1.46 to 3.72; P<0.001), with 57 virologic failures (14%) in the abacavir-lamivudine group versus 26 (7%) in the tenofovir DF-emtricitabine group. The time to the first adverse event was also shorter in the abacavir-lamivudine group (P<0.001). There was no significant difference between the study groups in the change from the baseline CD4 cell count at week 48.In patients with screening HIV-1 RNA levels of 100,000 copies per milliliter or more, the times to virologic failure and the first adverse event were both significantly shorter in patients randomly assigned to abacavir-lamivudine than in those assigned to tenofovir DF-emtricitabine. (ClinicalTrials.gov number, NCT00118898.)

    View details for Web of Science ID 000272257100006

    View details for PubMedID 19952143

  • Evolution and molecular epidemiology of subtype C HIV-1 in Zimbabwe AIDS Dalai, S. C., de Oliveira, T., Harkins, G. W., Kassaye, S. G., Lint, J., Manasa, J., Johnston, E., Katzenstein, D. 2009; 23 (18): 2523-2532

    Abstract

    To investigate the origins and evolutionary history of subtype C HIV-1 in Zimbabwe in a context of regional conflict and migration.HIV-1C pol sequence datasets were generated from four sequential cohorts of antenatal women in Harare, Zimbabwe sampled over 15 years (1991-2006).One hundred and seventy-seven HIV-1C pol sequences were obtained from four successive cohorts in Zimbabwe. Maximum-likelihood methods were used to explore phylogenetic relationships between Zimbabwean HIV-1C sequences and subtype C strains from other regions. A Bayesian coalescent-based framework was used to estimate evolutionary parameters for HIV-1C in Zimbabwe, including origin and demographic growth patterns.Zimbabwe HIV-1C pol demonstrated increasing sequence divergence over the 15-year period. Nearly all Zimbabwe sequences clustered phylogenetically with subtype C strains from neighboring countries. Bayesian evolutionary analysis indicated a most recent common ancestor date of 1973 with three epidemic growth phases: an initial, slow phase (1970s) followed by exponential growth (1980s), and a linearly expanding epidemic to the present. Bayesian trees provided evidence for multiple HIV-1C introductions into Zimbabwe during 1979-1981, corresponding with Zimbabwean national independence following a period of socio-political instability.The Zimbabwean HIV-1C epidemic likely originated from multiple introductions in the late 1970s and grew exponentially during the 1980s, corresponding to changing political boundaries and rapid population influx from neighboring countries. The timing and phylogenetic clustering of the Zimbabwean sequences is consistent with an origin in southern Africa and subsequent expansion. HIV-1 sequence data contain important epidemiological information, which can help focus treatment and prevention strategies in light of more recent political volatility in Zimbabwe.

    View details for DOI 10.1097/QAD.0b013e3283320ef3

    View details for Web of Science ID 000272135800017

    View details for PubMedID 19770693

    View details for PubMedCentralID PMC2923658

  • Expanding Antiretroviral Options in Resource-Limited Settings-A Cost-Effectiveness Analysis JAIDS-JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Bendavid, E., Wood, R., Katzenstein, D. A., Bayoumi, A. M., Owens, D. K. 2009; 52 (1): 106-113

    Abstract

    Current World Health Organization (WHO) guidelines for treatment of HIV in resource-limited settings call for 2 antiretroviral regimens. The effectiveness and cost-effectiveness of increasing the number of antiretroviral regimens is unknown.Using a simulation model, we compared the survival and costs of current WHO regimens with two 3-regimen strategies: an initial regimen of 3 nucleoside reverse transcriptase inhibitors followed by the WHO regimens and the WHO regimens followed by a regimen with a second-generation boosted protease inhibitor (2bPI). We evaluated monitoring with CD4 counts only and with both CD4 counts and viral load. We used cost and effectiveness data from Cape Town and tested all assumptions in sensitivity analyses.Over the lifetime of the cohort, 25.6% of individuals failed both WHO regimens by virologic criteria. However, when patients were monitored using CD4 counts alone, only 6.5% were prescribed additional highly active antiretroviral therapy due to missed and delayed detection of failure. The life expectancy gain for individuals who took a 2bPI was 6.7-8.9 months, depending on the monitoring strategy. When CD4 alone was available, adding a regimen with a 2bPI was associated with an incremental cost-effectiveness ratio of $2581 per year of life gained, and when viral load was available, the ratio was $6519 per year of life gained. Strategies with triple-nucleoside reverse transcriptase inhibitor regimens in initial therapy were dominated. Results were sensitive to the price of 2bPIs.About 1 in 4 individuals who start highly active antiretroviral therapy in sub-Saharan Africa will fail currently recommended regimens. At current prices, adding a regimen with a 2bPI is cost effective for South Africa and other middle-income countries by WHO standards.

    View details for PubMedID 19448557

  • TREAT Asia Quality Assessment Scheme (TAQAS) to standardize the outcome of HIV genotypic resistance testing in a group of Asian laboratories JOURNAL OF VIROLOGICAL METHODS Land, S., Cunningham, P., Zhou, J., Frost, K., Katzenstein, D., Kantor, R., Chen, Y. A., Oka, S., DeLong, A., Sayer, D., Smith, J., Dax, E. M., Law, M. 2009; 159 (2): 185-193

    Abstract

    The TREAT Asia (Therapeutics, Research, Education, and AIDS Training in Asia) Network is building capacity for Human Immunodeficiency Virus Type-1 (HIV-1) drug resistance testing in the region. The objective of the TREAT Asia Quality Assessment Scheme - designated TAQAS - is to standardize HIV-1 genotypic resistance testing (HIV genotyping) among laboratories to permit rigorous comparison of results from different clinics and testing centres. TAQAS has evaluated three panels of HIV-1-positive plasma from clinical material or low-passage, culture supernatant for up to 10 Asian laboratories. Laboratory participants used their standard protocols to perform HIV genotyping. Assessment was in comparison to a target genotype derived from all participants and the reference laboratory's result. Agreement between most participants at the edited nucleotide sequence level was high (>98%). Most participants performed to the reference laboratory standard in detection of drug resistance mutations (DRMs). However, there was variation in the detection of nucleotide mixtures (0-83%) and a significant correlation with the detection of DRMs (p<0.01). Interpretation of antiretroviral resistance showed approximately 70% agreement among participants when different interpretation systems were used but >90% agreement with a common interpretation system, within the Stanford University Drug Resistance Database. Using the principles of external quality assessment and a reference laboratory, TAQAS has demonstrated high quality HIV genotyping results from Asian laboratories.

    View details for DOI 10.1016/j.jviromet.2009.03.016

    View details for Web of Science ID 000267454000008

    View details for PubMedID 19490972

    View details for PubMedCentralID PMC2863146

  • Evaluation of two human immunodeficiency virus-1 genotyping systems: ViroSeq (TM) 2.0 and an in-house method JOURNAL OF VIROLOGICAL METHODS Saravanan, S., Vidya, M., Balakrishanan, P., Kumarasamy, N., Solomon, S. S., Solomon, S., Kantor, R., Katzenstein, D., Ramratnarn, B., Mayer, K. H. 2009; 159 (2): 211-216

    Abstract

    Commercial HIV-1 genotypic resistance assays are very expensive, particularly for use in resource-constrained settings like India. Hence a cost effective in-house assay for drug resistance was validated against the standard ViroSeq HIV-1 Genotyping System 2.0 (Celera Diagnostics, CA, USA). A total of 50 samples were used for this evaluation (21 proficiency panels and 29 clinical isolates). Known resistance positions within HIV-1 protease (PR) region (1-99 codons) and HIV-1 reverse-transcriptase (RT) region (1-240 codons) were included. The results were analysed for each codon as follows: (i) concordant; (ii) partially concordant; (iii) indeterminate and (iv) discordant. A total of 2750 codons (55 codons per patient samplex50 samples) associated with drug resistance (1050 PR and 1700 RT) were analysed. For PR, 99% of the codon results were concordant and 1% were partially concordant. For RT, 99% of the codon results were concordant, 0.9% were partially concordant and 0.1% were discordant. No indeterminate results were observed and the results were reproducible. Overall, the in-house assay provided comparable results to those of US FDA approved ViroSeq, which costs about a half of the commercial assay ($ 100 vs. $ 230), making it suitable for resource-limited settings.

    View details for DOI 10.1016/j.jviromet.2009.03.021

    View details for Web of Science ID 000267454000012

    View details for PubMedID 19490976

    View details for PubMedCentralID PMC2923210

  • Lack of Evidence for Frequent Heterosexual Transmission of Human Herpesvirus 8 in Zimbabwe 16th International AIDS Conference Campbell, T. B., Borok, M., Ndemera, B., Fiorillo, S., White, I. E., Zhang, X., Machekano, R. N., Katzenstein, D., Gwanzura, L. UNIV CHICAGO PRESS. 2009: 1601?8

    Abstract

    There is conflicting evidence about the contribution of heterosexual transmission to the spread of human herpesvirus 8 (HHV-8) in southern Africa. This study evaluated the hypothesis that HHV-8 infection is associated with risk factors for human immunodeficiency virus type 1 (HIV-1) and other sexually transmitted infections among Zimbabwean men.HHV-8 seroprevalence was determined for 2750 participants in the Zimbabwe AIDS Prevention Project cohort of male factory workers in Harare, Zimbabwe. Potential associations of HHV-8 antibody detection with risk factors for HIV-1 infection were examined by univariate analysis. Variables with P < .1 in the univariate analysis were included in a multivariate logistic regression model. HHV-8 seroprevalence was also determined among 297 heterosexual couples.Prevalence of HHV-8, HIV-1, and HHV-8 and HIV-1 coinfection was 28.5% (95% confidence interval [CI], 26.8%-30.2%), 19.5% (95% CI, 18.0%-20.9%), and 6.5% (95% CI, 5.6%-7.5%), respectively. Detection of HHV-8 antibodies was independently associated with older age and HIV-1 infection but not with number of recent sex partners, marital status, education, condom use, prior sexually transmitted infections, payment for sex, chronic hepatitis B infection, or incident HIV-1 infection. HHV-8 seroprevalence was 31.7% (95% CI, 26.3-37.0) among wives in the couples tested, but HHV-8 infection of wives was not associated with HHV-8 infection of husbands (odds ratio, 1.08; 95% CI, 0.62-1.88; P = .8).HHV-8 and HIV-1 infection did not have common sexual risk factors among urban Zimbabwean men. Sexual transmission does not explain the high prevalence of HHV-8 in this population.

    View details for DOI 10.1086/598978

    View details for Web of Science ID 000265749400017

    View details for PubMedID 19400749

  • CCR5-and CXCR4-Tropic Subtype C Human Immunodeficiency Virus Type 1 Isolates Have a Lower Level of Pathogenic Fitness than Other Dominant Group M Subtypes: Implications for the Epidemic JOURNAL OF VIROLOGY Abraha, A., Nankya, I. L., Gibson, R., Demers, K., Tebit, D. M., Johnston, E., Katzenstein, D., Siddiqui, A., Herrera, C., Fischetti, L., Shattock, R. J., Arts, E. J. 2009; 83 (11): 5592-5605

    Abstract

    Human immunodeficiency virus type 1 (HIV-1) subtype C is the dominant subtype globally, due largely to the incidence of subtype C infections in sub-Saharan Africa and east Asia. We compared the relative replicative fitness (ex vivo) of the major (M) group of HIV-1 subtypes A, B, C, D, and CRF01_AE and group O isolates. To estimate pathogenic fitness, pairwise competitions were performed between CCR5-tropic (R5) or CXCR4-tropic (X4) virus isolates in peripheral blood mononuclear cells (PBMC). A general fitness order was observed among 33 HIV-1 isolates; subtype B and D HIV-1 isolates were slightly more fit than the subtype A and dramatically more fit than the 12 subtype C isolates. All group M isolates were more fit (ex vivo) than the group O isolates. To estimate ex vivo transmission fitness, a subset of primary HIV-1 isolates were examined in primary human explants from penile, cervical, and rectal tissues. Only R5 isolates and no X4 HIV-1 isolates could replicate in these tissues, whereas the spread to PM1 cells was dependent on active replication and passive virus transfer. In tissue competition experiments, subtype C isolates could compete with and, in some cases, even win over subtype A and D isolates. However, when the migratory cells from infected tissues were mixed with a susceptible cell line, the subtype C isolates were outcompeted by other subtypes, as observed in experiments with PBMC. These findings suggest that subtype C HIV-1 isolates might have equal transmission fitness but reduced pathogenic fitness relative to other group M HIV-1 isolates.

    View details for DOI 10.1128/JVI.02051-08

    View details for Web of Science ID 000266034100029

    View details for PubMedID 19297481

    View details for PubMedCentralID PMC2681953

  • Envelope Coreceptor Tropism, Drug Resistance, and Viral Evolution Among Subtype C HIV-1-Infected Individuals Receiving Nonsuppressive Antiretroviral Therapy 29th Annual Meeting of the Society-of-Behavioral-Medicine Kassaye, S., Johnston, E., McColgan, B., Kantor, R., Enah, L. Z., Katzenstein, D. LIPPINCOTT WILLIAMS & WILKINS. 2009: 9?18

    Abstract

    In resource-constrained settings, antiretroviral treatment (ART) is often continued based on clinical and CD4 responses, without virologic monitoring. ART with incomplete viral suppression was assessed in 27 subjects with subtype C HIV-1.Plasma HIV-1 RNA, drug resistance, viral tropism, and evolution in polymerase (pol) and envelope (env) genes were measured. The association between these viral parameters and CD4 cell change over time was analyzed using linear regression models.Increased area under the curve of HIV-1 RNA replication was a predictor of lower CD4 cell gains (P < 0.007), while less drug resistance measured as a genotypic susceptibility score (GSS) (P = 0.065), and lower rates of evolution in pol and env genes (P = 0.08 and 0.097, respectively) measured as genetic distance were modestly associated with increasing CD4 cell counts. Evolution of pol and env were correlated (R2 = 0.48, P = 0.005), however, greater evolution was identified in env vs. pol (P < 0.05). CXCR4-usage (X4) was detected in 14/27 (52%) but no differences in CD4 cell change or plasma viremia were associated with X4-usage.Among subtype C HIV-1 infected patients in Zimbabwe receiving incompletely suppressive ART, higher virus replication and lower CD4 cell gains were associated with drug resistance and evolution of polymerase and envelope.

    View details for Web of Science ID 000262019100002

    View details for PubMedID 19295330

  • Genotypic HIV type-1 drug resistance among patients with immunological failure to first-line antiretroviral therapy in south India ANTIVIRAL THERAPY Vidya, M., Saravanan, S., Uma, S., Kumarasamy, N., Sunil, S. S., Kantor, R., Katzenstein, D., Ramratnam, B., Mayer, K. H., Suniti, S., Balakrishnan, P. 2009; 14 (7): 1005-1009

    Abstract

    HIV type-1 (HIV-1) monitoring in resource-limited settings relies on clinical and immunological assessment. The objective of this study was to study the frequency and pattern of reverse transcriptase (RT) drug resistance among patients with immunological failure (IF) to first-line therapy.A cross-sectional study of 228 patients with IF was done, of which 126 were drug-naive (group A) when starting highly active antiretroviral therapy (HAART) and 102 were exposed to mono/dual therapy prior to HAART initiation (group B). A validated in-house genotyping method and Stanford interpretation was used. Means, sd, median and frequencies (as percentages) were used to indicate the patient characteristics in each group. The chi(2) test and Fisher's exact test were used to compare categorical variables as appropriate. All analyses were performed using SPSS software, version 13.0. P-values <0.05 were considered to be statistically significant.RT drug resistance mutations were found in 92% and 96% of patients in groups A and B, respectively. Median (interquartile range) CD4(+) T-cell count at failure was 181 cells/microl (18-999) and time to failure was 40 months (2-100). M184V (80% versus 75%), thymidine analogue mutations (63% versus 74%), Y181C (39% versus 39%) and K103N (29% versus 39%) were predominant RT mutations in both groups. Extensive nucleoside reverse transcriptase inhibitor cross-resistance mutations were observed in 51% and 26% of patients in group B and A, respectively.Alternative strategies for initial therapy and affordable viral load monitoring could reduce resistance accumulations and preserve available drugs for future options in resource-limited settings.

    View details for DOI 10.3851/IMP1411

    View details for Web of Science ID 000272060000014

    View details for PubMedID 19918105

    View details for PubMedCentralID PMC3816397

  • Quality of life, psychosocial health, and antiretroviral therapy among HIV-positive women in Zimbabwe AIDS CARE-PSYCHOLOGICAL AND SOCIO-MEDICAL ASPECTS OF AIDS/HIV Patel, R., Kassaye, S., Gore-Felton, C., Wyshak, G., Kadzirange, G., Woelk, G., Katzenstein, D. 2009; 21 (12): 1517-1527

    Abstract

    Little is known about the psychosocial impact of antiretroviral therapy (ART) among women in sub-Saharan Africa. Therefore, we conducted a cross-sectional study in Zimbabwe to assess the impact of ART on HIV-positive women's health-related quality of life, using the Medical Outcomes Study-HIV Quality of Life (QOL) questionnaire. Additionally, we assessed socio-demographics, reproductive and sexual health, HIV-related history, disclosure, social stigma, self-esteem, and depression. Structured interviews were conducted with 200 HIV-positive women and categorized into three groups by treatment: (1) Group 1 (n=31) did not meet clinical or laboratory criteria to begin treatment; (2) Group 2 (n=73) was eligible to begin treatment but awaiting initiation of treatment; and (3) Group 3 (n=96) was on ART for a median of 13 months. The women had similar socio-demographic characteristics but varied significantly in clinical characteristics. Women on ART reported fewer AIDS-related symptoms in the last week and year and had higher current and lower baseline CD4 counts compared to women not on ART. On most QOL domains women on ART reported higher mean scores as compared to women not on ART (p<0.01). Additionally, women on ART reported less depression compared to women not on ART (p<0.001). Between the two groups of women not on ART, unexpectedly, there were no significant differences in their scores for QOL or depression. Thus, Zimbabwean women living with HIV experience better overall QOL and lower depression on ART. Altogether, our findings suggest that ART delivery in resource-poor communities can enhance overall QOL as well as psychosocial functioning, which has wide-ranging public health implications.

    View details for DOI 10.1080/09540120902923055

    View details for Web of Science ID 000273008700005

    View details for PubMedID 20024731

  • Alanine aminotransferase levels are not significantly elevated in patients with HIV/HBV co-infection and lamivudine resistance INTERNATIONAL JOURNAL OF STD & AIDS Bhattacharya, D., KATZENSTEIN, D., Wong, A., Israelski, D., Imperial, J. C., Keeffe, E. B., DONOVAN, R. M. 2008; 19 (11): 780-781

    Abstract

    In hepatitis B virus (HBV) monoinfection, alanine aminotransferase (ALT) levels are linearly correlated with HBV DNA levels and lamivudine resistance. In human immunodeficiency virus (HIV)/HBV co-infection, little is known about the association between ALT, HBV DNA, and lamivudine resistance. We assessed HBV DNA, lamivudine resistance and ALT levels in 45 time points in 11 patients with HIV/HBV co-infection during lamivudine-containing antiretroviral therapy. High HBV DNA levels (>10(6) copies/mL) and lamivudine resistance developed in 45% and 91% of patients, respectively. However, ALT levels were not elevated in the setting of high HBV DNA levels (mean ALT, 48 IU/mL) or lamivudine resistance (mean ALT, 44 IU/mL). HBV viraemia and lamivudine resistance during extended lamivudine-containing antiretroviral therapy are common in HIV/HBV co-infection, occurring in the absence of significant ALT elevations. In HIV/HBV co-infection, measurement of HBV DNA and HBV resistance mutations may identify HBV virological failure before biochemical changes and should be routinely used in the management of HIV/HBV co-infection.

    View details for DOI 10.1258/ijsa.2008.008020

    View details for Web of Science ID 000260950100012

    View details for PubMedID 18931274

    View details for PubMedCentralID PMC2914094

  • Bayesian network analyses of resistance pathways against efavirenz and nevirapine AIDS Deforche, K., Camacho, R. J., Grossman, Z., Soares, M. A., Van Laethem, K., Katzenstein, D. A., Harrigan, P. R., Kantor, R., Shafer, R., Vandamme, A. 2008; 22 (16): 2107-2115

    Abstract

    To clarify the role of novel mutations selected by treatment with efavirenz or nevirapine, and investigate the influence of HIV-1 subtype on nonnucleoside reverse transcriptase inhibitor (nNRTI) resistance pathways.By finding direct dependencies between treatment-selected mutations, the involvement of these mutations as minor or major resistance mutations against efavirenz, nevirapine, or coadministrated nucleoside analogue reverse transcriptase inhibitors (NRTIs) is hypothesized. In addition, direct dependencies were investigated between treatment-selected mutations and polymorphisms, some of which are linked with subtype, and between NRTI and nNRTI resistance pathways.Sequences from a large collaborative database of various subtypes were jointly analyzed to detect mutations selected by treatment. Using Bayesian network learning, direct dependencies were investigated between treatment-selected mutations, NRTI and nNRTI treatment history, and known NRTI resistance mutations.Several novel minor resistance mutations were found: 28K and 196R (for resistance against efavirenz), 101H and 138Q (nevirapine), and 31L (lamivudine). Robust interactions between NRTI mutations (65R, 74V, 75I/M, and 184V) and nNRTI resistance mutations (100I, 181C, 190E and 230L) may affect resistance development to particular treatment combinations. For example, an interaction between 65R and 181C predicts that the nevirapine and tenofovir and lamivudine/emtricitabine combination should be more prone to failure than efavirenz and tenofovir and lamivudine/emtricitabine.Bayesian networks were helpful in untangling the selection of mutations by NRTI versus nNRTI treatment, and in discovering interactions between resistance mutations within and between these two classes of inhibitors.

    View details for DOI 10.1097/QAD.0b013e32830fe940

    View details for Web of Science ID 000260436600008

    View details for PubMedID 18832874

  • Cost-effectiveness of HIV monitoring strategies in resource-limited settings - A Southern African analysis ARCHIVES OF INTERNAL MEDICINE Bendavid, E., Young, S. D., Katzenstein, D. A., Bayoumi, A. M., Sanders, G. D., Owens, D. K. 2008; 168 (17): 1910-1918

    Abstract

    Although the number of infected persons receiving highly active antiretroviral therapy (HAART) in low- and middle-income countries has increased dramatically, optimal disease management is not well defined.We developed a model to compare the costs and benefits of 3 types of human immunodeficiency virus monitoring strategies: symptom-based strategies, CD4-based strategies, and CD4 counts plus viral load strategies for starting, switching, and stopping HAART. We used clinical and cost data from southern Africa and performed a cost-effectiveness analysis. All assumptions were tested in sensitivity analyses.Compared with the symptom-based approaches, monitoring CD4 counts every 6 months and starting treatment at a threshold of 200/muL was associated with a gain in life expectancy of 6.5 months (61.9 months vs 68.4 months) and a discounted lifetime cost savings of US $464 per person (US $4069 vs US $3605, discounted 2007 dollars). The CD4-based strategies in which treatment was started at the higher threshold of 350/microL provided an additional gain in life expectancy of 5.3 months at a cost-effectiveness of US $107 per life-year gained compared with a threshold of 200/microL. Monitoring viral load with CD4 was more expensive than monitoring CD4 counts alone, added 2.0 months of life, and had an incremental cost-effectiveness ratio of US $5414 per life-year gained relative to monitoring of CD4 counts. In sensitivity analyses, the cost savings from CD4 count monitoring compared with the symptom-based approaches was sensitive to cost of inpatient care, and the cost-effectiveness of viral load monitoring was influenced by the per test costs and rates of virologic failure.Use of CD4 monitoring and early initiation of HAART in southern Africa provides large health benefits relative to symptom-based approaches for HAART management. In southern African countries with relatively high costs of hospitalization, CD4 monitoring would likely reduce total health care expenditures. The cost-effectiveness of viral load monitoring depends on test prices and rates of virologic failure.

    View details for PubMedID 18809819

  • Cytomegalovirus and Epstein-Barr virus in breast milk are associated with HIV-1 shedding but not with mastitis 13th Conference on Retroviruses and Opportunistic Infections Gantt, S., Carlsson, J., Shetty, A. K., Seidel, K. D., Qin, X., Mutsvangwa, J., Musingwini, G., Woelk, G., Zijenah, L. S., Katzenstein, D. A., Frenkel, L. M. LIPPINCOTT WILLIAMS & WILKINS. 2008: 1453?60

    Abstract

    Breast milk HIV-1 load is associated with clinical and subclinical mastitis, and both milk viral load and mastitis are associated with increased mother-to-child-transmission of HIV-1 through breastfeeding. Bacterial infections may cause clinical mastitis, but whether other copathogens common in HIV-1 infection are associated with subclinical mastitis or HIV-1 shedding is unknown.A cross-sectional study of HIV-1-infected breastfeeding women in Zimbabwe was performed to examine the relationship between a wide range of breast coinfections, mastitis, and HIV-1 shedding.Breast milk was cultured for bacteria and fungi and tested by PCR for mycobacteria, mycoplasmas, human herpesvirus (HHV)-6, HHV-7, HHV-8, cytomegalovirus, Epstein-Barr virus, and HIV-1 RNA and DNA. Symptoms of clinical mastitis were documented and subclinical mastitis was identified by breast milk sodium concentration (Na) and leukocyte counts.Coinfections of milk were not associated with clinical or subclinical mastitis in the 217 women studied. Detection of HIV-1 RNA, but not DNA, in breast milk was associated with cytomegalovirus concentration (odds ratio = 1.8, P = 0.002) and detection of Epstein-Barr virus (odds ratio = 3.8, P = 0.0003) but not other coinfections in multivariate analysis.Coinfection of breast milk with bacteria, fungi, or herpes viruses was not associated with mastitis. The associations between shedding of cytomegalovirus and Epstein-Barr virus with HIV-1 in milk suggest a local interaction between herpes virus infection and HIV-1 independent of mastitis. Cytomegalovirus and Epstein-Barr virus infections may impact HIV-1 shedding in breast milk and the risk of MTCT.

    View details for Web of Science ID 000258048100008

    View details for PubMedID 18614868

    View details for PubMedCentralID PMC2504751

  • Genotypic susceptibility scores and HIV type 1 RNA responses in treatment-experienced subjects with HIV type 1 infection AIDS RESEARCH AND HUMAN RETROVIRUSES Anderson, J. A., Jiang, H., Ding, X., Petch, L., Journigan, T., Fiscus, S. A., Haubrich, R., Katzenstein, D., Swanstrom, R., Gulick, R. M. 2008; 24 (5): 685-694

    Abstract

    This study compared the role of genotypic susceptibility scores (GSS) as a predictor of virologic response in a group (n = 234) of HIV-infected, protease inhibitor (PI)-experienced subjects. Two scoring methods [discrete genotypic susceptibility score (dGSS) and continuous genotypic susceptibility score (cGSS)] were developed. Each drug in the subject's regimen was given a binary susceptibility score using Stanford inferred drug resistance scores to calculate the dGSS. In contrast to the dGSS, the cGSS model was designed to reflect partial susceptibility to a drug. Both GSS were independent predictors of week 16 virologic response. We also compared the GSS to a phenotypic susceptibility score (PSS) model on a subset of subjects that had both GSS and PSS performed, and found that both models were predictive of virologic response. Genotypic analyses at enrollment showed that subjects who were virologic nonresponders at week 16 revealed enrichment of several mutated codons associated with nucleoside reverse transcriptase inhibitors (NRTI) (codons 67, 69, 70, 118, 215, and 219) or PI resistance (codons 10, 24, 71, 73, and 88) compared to subjects who were virologic responders. Regression analyses revealed that protease mutations at codons 24 and 90 were most predictive of poor virologic response, whereas mutations at 82 were associated with enhanced virologic response. Certain NNRTI-associated mutations, such as K103N, were rapidly selected in the absence of NRTIs. These data indicate that GSS may be a useful tool in selecting drug regimens in HIV-1-infected subjects to maximize virologic response and improve treatment outcomes.

    View details for DOI 10.1089/aid.2007.0127

    View details for Web of Science ID 000256519300004

    View details for PubMedID 18462083

    View details for PubMedCentralID PMC2928289

  • Metabolic and Immune Activation Effects of Treatment Interruption in Chronic HIV-1 Infection: Implications for Cardiovascular Risk PLOS ONE Tebas, P., Henry, W. K., Matining, R., Weng-Cherng, D., Schmitz, J., Valdez, H., Jahed, N., Myers, L., Powderly, W. G., Katzenstein, D. 2008; 3 (4)

    Abstract

    Concern about costs and antiretroviral therapy (ART)-associated toxicities led to the consideration of CD4 driven strategies for the management of HIV. That approach was evaluated in the SMART trial that reported an unexpected increase of cardiovascular events after treatment interruption (TI). Our goal was to evaluate fasting metabolic changes associated with interruption of antiretroviral therapy and relate them to changes of immune activation markers and cardiovascular risk.ACTG 5102 enrolled 47 HIV-1-infected subjects on stable ART, with <200 HIV RNA copies/mL and CD4 cell count >or=500 cells/microL. Subjects were randomly assigned to continue ART for 18 weeks with or without 3 cycles of interleukin-2 (IL-2) (cycle = 4.5 million IU sc BID x 5 days every 8 weeks). After 18 weeks ART was discontinued in all subjects until the CD4 cell count dropped below 350 cells/microL. Glucose and lipid parameters were evaluated every 8 weeks initially and at weeks 2, 4, 8 and every 8 weeks after TI. Immune activation was evaluated by flow-cytometry and soluble TNFR2 levels.By week 8 of TI, levels of total cholesterol (TC) (median (Q1, Q3) (-0.73 (-1.19, -0.18) mmol/L, p<0.0001), LDL, HDL cholesterol (-0.36(-0.73,-0.03)mmol/L, p = 0.0007 and -0.05(-0.26,0.03), p = 0.0033, respectively) and triglycerides decreased (-0.40 (-0.84, 0.07) mmol/L, p = 0.005). However the TC/HDL ratio remained unchanged (-0.09 (-1.2, 0.5), p = 0.2). Glucose and insulin levels did not change (p = 0.6 and 0.8, respectively). After TI there was marked increase in immune activation (CD8+/HLA-DR+/CD38+ cells, 34% (13, 43), p<0.0001) and soluble TNFR2 (1089 ng/L (-189, 1655), p = 0.0008) coinciding with the rebound of HIV viremia.Our data suggests that interrupting antiretroviral therapy does not reduce cardiovascular disease (CVD) risk, as the improvements in lipid parameters are modest and overshadowed by the decreased HDL levels. Increased immune cell activation and systemic inflammatory responses associated with recrudescent HIV viremia may provide a more cogent explanation for the increased cardiovascular risk associated with treatment interruption and HIV infection.ClinicalTrials.gov NCT00015704.

    View details for DOI 10.1371/journal.pone.0002021

    View details for Web of Science ID 000261558700033

    View details for PubMedID 18431498

    View details for PubMedCentralID PMC2292263

  • A multicenter trial of selegiline transdermal system for HIV-associated cognitive impairment NEUROLOGY Schifitto, G., Zhang, J., Evans, S. R., Sacktor, N., Simpson, D., Millar, L. L., HUNG, V. L., Miller, E. N., Smith, E., Ellis, R. J., Valcour, V., Singer, E., Marra, C. M., Kolson, D., Weihe, J., Remmel, R., KATZENSTEIN, D., Clifford, D. B. 2007; 69 (13): 1314-1321

    Abstract

    Cognitive impairment continues to be a significant neurologic complication of HIV infection and has been associated with oxidative stress-induced neuronal injury. Selegiline is an MAO-B inhibitor with antioxidant and neurotrophic properties. This rationale has led to the design and implementation of this Selegiline Transdermal System (STS) study with the primary aims of assessing safety and tolerability of STS as well as improvement in cognitive performance.HIV-1 infected individuals with impaired cognitive functioning were enrolled in this placebo-controlled, three-arm study of STS across 17 sites. Cognitive impairment was determined using a standard battery of neuropsychological tests. Subjects were randomized to receive STS 3 mg/24 hours, STS 6 mg/24 hours, or matching placebo patches daily. The primary efficacy endpoint was defined as the change in neuropsychological composite Z-score (NPZ-6) from baseline to week 24. Measures of safety included frequencies of adverse experiences and abnormal results on laboratory tests.A total of 128 subjects (88% men, 51% white) were enrolled, median age 45 years. Most subjects (62%) had mild to moderate AIDS dementia complex. The 24-week NPZ-6 median (interquartile range) changes were 0.22 (-0.28, 0.55) for the selegiline 3 mg/24 hours arm, 0.21 (-0.18, 0.62) for the selegiline 6 mg/24 hours arm, and 0.28 (-0.16, 0.64) for the placebo arm (a positive score indicates improvement from baseline) (p = 0.914). Severe laboratory abnormalities were few and occurred in similar proportion among the three treatment arms.Selegiline was safe and well tolerated by HIV-infected individuals with cognitive impairment and mild to moderate immune suppression; however, no cognitive or functional improvement was observed in this phase II study.

    View details for Web of Science ID 000249694800004

    View details for PubMedID 17652642

  • Laboratory indicators of mastitis are not associated with elevated HIV-1 DNA loads or predictive of HIV-1 RNA loads in breast milk 13th Conference on Retroviruses and Opportunistic Infections Gantt, S., Shetty, A. K., Seidel, K. D., Matasa, K., Musingwini, G., Woelk, G., Zijenah, L. S., Katzenstein, D. A., Frenkel, L. M. OXFORD UNIV PRESS INC. 2007: 570?76

    Abstract

    Mother-to-child transmission (MTCT) of HIV-1 has been associated with symptomatic and asymptomatic mastitis and with the quantity of HIV-1 RNA and DNA in maternal milk. An improved understanding of the relationship between indicators of inflammation and HIV-1 loads in breast milk could improve MTCT prevention strategies.In a cross-sectional study, laboratory indicators of mastitis (breast milk sodium [Na(+)] concentration, sodium : potassium ratio [Na(+) : K(+)], and leukocyte count) were related to breast milk HIV-1 RNA and DNA loads and were evaluated for predicting viral loads in milk.Mastitis was present in 63 (15%) of 407, 60 (15%) of 407, and 76 (18%) of 412 milk specimens, as defined by Na(+) concentration >12 mmol/L, Na(+) : K(+) >1, and total leukocyte counts > or =10(6) cells/mL, respectively. Each indicator was associated with an increased milk HIV-1 RNA load (P<.05) but not with HIV-1 DNA load. Neutrophils correlated better with milk HIV-1 RNA load than total leukocytes. However, neither neutrophil count, Na(+) concentration, nor Na(+) : K(+) displayed a threshold that was both sensitive and specific for the detection of HIV-1 RNA in milk at thresholds of > or =50 or > or =10(4) copies/mL.HIV-1 DNA loads in breast milk were not increased during mastitis. Neither milk cell counts nor electrolyte concentrations were useful predictors of milk HIV-1 RNA or DNA loads for individual women.

    View details for DOI 10.1086/519843

    View details for Web of Science ID 000248037300013

    View details for PubMedID 17624843

  • Drug resistance in plasma and breast milk after single-dose nevirapine in subtype C HIV type 1: Population and clonal sequence analysis AIDS RESEARCH AND HUMAN RETROVIRUSES Kassaye, S., Lee, E., Kantor, R., Johnston, E., Winters, M., Zijenah, L., Mateta, P., Katzenstein, D. 2007; 23 (8): 1055-1061

    Abstract

    Single-dose nevirapine (SD NVP) reduces intrapartum HIV-1 transmission, but nonnucleoside reverse transcription (NNRTI) resistance mutations can emerge. Population sequencing among 32 subtype C HIV-1-infected, SD NVP-exposed Zimbawean women demonstrated NNRTI resistance in 25/32 (78%) women: 23/30 (77%) at 2 weeks, 11/31 (35%) at 8 weeks, and 5/27 (19%) at 24 weeks. A total of 447 unique TA clones (median = 28 per time point), from four women with resistance at 8 weeks but wild-type virus by population sequence at 24 weeks, identified NNRTI mutations in a median of 76% (range: 55-96%) of individual clones at 2 weeks, 48% (range: 33-80%) at 8 weeks, and 5% (range: 0-15%) by 24 weeks. NNRTI mutations in breast milk clones at 2 and weeks from one woman varied significantly from plasma. Population sequencing underestimates the diversity of NNRTI resistance mutations within minority populations following SD NVP in subtype C HIV-1 viral RNA in plasma and breast milk.

    View details for DOI 10.1089/aid.2007.0045

    View details for Web of Science ID 000249143200014

    View details for PubMedID 17725424

  • More on the treatment-tropism relationship: The impact of prior antiretroviral treatment on HIV coreceptor tropism among subjects entering AIDS clinical trials group 175 JOURNAL OF INFECTIOUS DISEASES Shulman, N. S., Kassaye, S. G., Winters, M. A., Johnston, E., Katzenstein, D. A. 2007; 196 (2): 328-329

    View details for DOI 10.1086/518896

    View details for Web of Science ID 000247803100022

    View details for PubMedID 17570122

  • Bayesian network analysis of resistance pathways against HIV-1 protease inhibitors 11th International Workshop on Virus Evolution and Molecular Epidemiology Deforche, K., Camacho, R., Grossman, Z., Silander, T., Soares, M. A., Moreau, Y., Shafer, R. W., Van Laethem, K., CARVALHO, A. P., Wynhoven, B., Cane, P., Snoeck, J., Clarke, J., Sirivichayakul, S., Ariyoshi, K., Holguin, A., Rudich, H., Rodrigues, R., Bouzas, M. B., Cahn, P., Brigido, L. F., Soriano, V., Sugiura, W., Phanuphak, P., Morris, L., Weber, J., Pillay, D., Tanuri, A., Harrigan, P. R., Shapiro, J. M., Katzenstein, D. A., Kantor, R., Vandamme, A. ELSEVIER SCIENCE BV. 2007: 382?90

    Abstract

    Interpretation of Human Immunodeficiency Virus 1 (HIV-1) genotypic drug resistance is still a major challenge in the follow-up of antiviral therapy in infected patients. Because of the high degree of HIV-1 natural variation, complex interactions and stochastic behaviour of evolution, the role of resistance mutations is in many cases not well understood. Using Bayesian network learning of HIV-1 sequence data from diverse subtypes (A, B, C, F and G), we could determine the specific role of many resistance mutations against the protease inhibitors (PIs) nelfinavir (NFV), indinavir (IDV), and saquinavir (SQV). Such networks visualize relationships between treatment, selection of resistance mutations and presence of polymorphisms in a graphical way. The analysis identified 30N, 88S, and 90M for nelfinavir, 90M for saquinavir, and 82A/T and 46I/L for indinavir as most probable major resistance mutations. Moreover we found striking similarities for the role of many mutations against all of these drugs. For example, for all three inhibitors, we found that the novel mutation 89I was minor and associated with mutations at positions 90 and 71. Bayesian network learning provides an autonomous method to gain insight in the role of resistance mutations and the influence of HIV-1 natural variation. We successfully applied the method to three protease inhibitors. The analysis shows differences with current knowledge especially concerning resistance development in several non-B subtypes.

    View details for DOI 10.1016/j.meegid.2006.09.004

    View details for Web of Science ID 000246855600006

    View details for PubMedID 17127103

  • Non-nucleoside phenotypic hypersusceptibility cut-point determination from ACTG 359 HIV CLINICAL TRIALS Haubrich, R. H., Jiang, H., Swanstrom, R., Bates, M., Katzenstein, D., Petch, L., Fletcher, C. V., Fiscus, S. A., Gulick, R. M. 2007; 8 (2): 63-67

    Abstract

    Non-nucleoside reverse transcriptase inhibitor (NNRTI) hypersusceptibility (HS) improves virologic response to those agents, but phenotypic susceptibility cut-points, and methods to determine the cut-points, have not been completely defined.Phenotypic drug susceptibility (fold change in IC50 [FC]) was determined for 96 randomly selected antiretroviral-experienced, NNRTI-naive patients who received a delavirdine (DLV)-containing regimen in ACTG 359. A weighted FC score was used to account for other regimen agents. Regression models were used to define baseline DLV HS cut-points using week 4 or week 16 responses.At study entry, DLV HS was present in 36% (35/96) of patients. Models explored HS cut-points from 0.2-1.0 using the week 4 virologic response. Using either a binary or continuous endpoint, DLV HS cut-points between 0.3 and 0.4 were identified. The classification and regression tree (CART) analysis identified baseline DLV FC <0.44 as a predictor of week 4 response.In relating drug HS to virologic response, several different analytic methods identified a DLV HS FC cut-point of 0.3-0.4. In refining phenotypic cut-points, early virologic responses (not confounded by rebound) may be better metrics than later responses, especially for drugs with low genetic barriers, such as DLV.

    View details for DOI 10.1310/hct0802-63

    View details for Web of Science ID 000246698100001

    View details for PubMedID 17507321

  • Factors in the delayed HIV presentation of immigrants in Northern California: implications for voluntary counseling and testing programs. Journal of immigrant and minority health Levy, V., Prentiss, D., Balmas, G., Chen, S., Israelski, D., Katzenstein, D., Page-Shafer, K. 2007; 9 (1): 49-54

    Abstract

    To describe the determinants of delayed HIV presentation in one Northern California County, the authors identify persons with an opportunistic infection (OI) at HIV diagnosis. From 2000-2002, a sample of HIV patients attending a public AIDS program (n=391) were identified. Immigrants composed 24% of our sample; 78.7% of immigrants were Hispanic. Immigrants, compared to U.S.-born patients, presented with lower initial CD4+ counts at diagnosis than U.S.-born patients (287 cells/mm(3) vs. 333 cells/mm(3), p=0.143), were more likely to have an OI at HIV diagnosis (29.8% vs. 17.2%, p=0.009), and were more likely to be hospitalized at HIV diagnosis (20.2% vs. 12.5%, p=0.064). We found only immigrant status was significantly and independently associated with delayed presentation. Interviews with 20 newly HIV diagnosed Hispanic patients suggest lack of knowledge regarding HIV risk, social stigma, secrecy and symptom driven health seeking behavior all contribute to delayed clinical presentation. The main precipitants of HIV testing for immigrants were HIV/AIDS related symptoms and sexually transmitted infection (STI)/HIV diagnosis in a sexual partner. These results support augmentation of STI/HIV voluntary clinical testing and partner notification services along the Mexico-California migrant corridor.

    View details for PubMedID 17031578

  • Genetic distance of rebound viraemia from proviral DNA and the selection of drug-resistance mutations in HIV-1 RNA after treatment interruption 16th International HIV Drug Resistance Workshop Dalai, S., Winters, M., Kassaye, S., KATZENSTEIN, D. INT MEDICAL PRESS LTD. 2007: S108?S108
  • Perceived risks and benefits of HIV testing, and predictors of acceptance of HIV counselling and testing among pregnant women in Zimbabwe INTERNATIONAL JOURNAL OF STD & AIDS Martin-Herz, S. P., Shetty, A. K., Bassett, M. T., Ley, C., Mhazo, M., Moyo, S., Herz, A. M., Katzenstein, D. 2006; 17 (12): 835-841

    Abstract

    This project evaluated perceived risks and benefits and determined predictors of acceptance of voluntary HIV counselling and testing (VCT) among pregnant women in Zimbabwe. One hundred and seventy pregnant women attending an urban antenatal clinic were surveyed. Implications of a negative or positive HIV test result and of telling a partner or community members that one is HIV positive were queried. Forty women (23.5%) consented to VCT, and 16 (40%) were HIV positive. Women who saw VCT as lower risk (odds ratio [OR] = 2.3, 95% confidence interval [CI] [1.1-5.0]) and women who had had a stillbirth or child die (OR = 0.4, 95% CI [0.16-0.97]) were more likely to consent. Prenatal HIV VCT offers the best opportunity for prevention of mother-to-child transmission of HIV; however, less than 25% of women consented. If such interventions are to be successful, attention must be directed towards developing culturally appropriate strategies to address women's concerns and improve future acceptance of VCT in Zimbabwe.

    View details for Web of Science ID 000243218900012

    View details for PubMedID 17212862

  • Diversity, drug resistance, and the epidemic of subtype CHIV-1 in Africa Symposium on Bridging Generations Toward an Understanding of Infectious Disease Pathogenesis Katzenstein, D. UNIV CHICAGO PRESS. 2006: S45?S50

    Abstract

    The human immunodeficiency virus (HIV) infection/acquired immunodeficiency syndrome (AIDS) epidemic has grown from a handful of sentinel observations in New York and California, nearly 25 years ago, to an epidemic that has claimed 500,000 lives in the United States and >20 million worldwide. Tom Merigan's scientific career led him to focus on viral pathogenesis as translational "bench-to-bedside" research, aimed squarely at the development of antiretroviral treatment. As a founder and leader of the AIDS Clinical Trials Group, Tom played a pivotal role in the national response to HIV. He led the development of a succession of antiretroviral drugs, their combined use, and the introduction of new methods for monitoring HIV infection. The current response to the global epidemic and the tools now coming to bear on diagnosis, treatment, and monitoring owe much to Tom's relentless pursuit of excellence in research and the training he offered generations of clinical virologists and infectious disease physicians.

    View details for Web of Science ID 000240317800008

    View details for PubMedID 16921472

  • Treatment for adult HIV infection - 2006 recommendations of the International AIDS Society-USA panel JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION Hammer, S. M., Saag, M. S., Schechter, M., Montaner, J. S., Schooley, R. T., Jacobsen, D. M., Thompson, M. A., Carpenter, C. C., Fischl, M. A., Gazzard, B. G., Gatell, J. M., Hirsch, M. S., Katzenstein, D. A., Richman, D. D., Vella, S., Yeni, P. G., Volberding, P. A. 2006; 296 (7): 827-843

    Abstract

    Guidelines for antiretroviral therapy are important for clinicians worldwide given the complexity of the field and the varied clinical situations in which these agents are used. The International AIDS Society-USA panel has updated its recommendations as warranted by new developments in the field.To provide physicians and other human immunodeficiency virus (HIV) clinicians with current recommendations for the use of antiretroviral therapy in HIV-infected adults in circumstances for which there is relatively unrestricted access to drugs and monitoring tools. The recommendations are centered on 4 key issues: when to start antiretroviral therapy; what to start; when to change; and what to change. Antiretroviral therapy in special circumstances is also described.A 16-member noncompensated panel was appointed, based on expertise in HIV research and patient care internationally. Data published or presented at selected scientific conferences from mid 2004 through May 2006 were identified and reviewed by all members of the panel.Data that might change previous guidelines were identified and reviewed. New guidelines were drafted by a writing committee and reviewed by the entire panel.Antiretroviral therapy in adults continues to evolve rapidly, making delivery of state-of-the-art care challenging. Initiation of therapy continues to be recommended in all symptomatic persons and in asymptomatic persons after the CD4 cell count falls below 350/microL and before it declines to 200/microL. A nonnucleoside reverse transcriptase inhibitor or a protease inhibitor boosted with low-dose ritonavir each combined with 2 nucleoside (or nucleotide) reverse transcriptase inhibitors is recommended with choice being based on the individual patient profile. Therapy should be changed when toxicity or intolerance mandate it or when treatment failure is documented. The virologic target for patients with treatment failure is now a plasma HIV-1 RNA level below 50 copies/mL. Adherence to antiretroviral therapy in the short-term and the long-term is crucial for treatment success and must be continually reinforced.

    View details for Web of Science ID 000239763400023

    View details for PubMedID 16905788

  • Affordable flow cytometry for enumeration of absolute CD4(+) T-lymphocytes to identify subtype CHIV-1 infected adults requiring antiretroviral therapy (ART) and monitoring response to ART in a resource-limited setting JOURNAL OF TRANSLATIONAL MEDICINE Zijenah, L. S., Kadzirange, G., Madzime, S., Borok, M., Mudiwa, C., Tobaiwa, O., Mucheche, M., Rusakaniko, S., Katzenstein, D. A. 2006; 4

    Abstract

    The World Health Organization (WHO)'s "3 x 5 program" has spurred efforts to place 3 million people on combination antiretroviral therapy (ART) for treatment of AIDS in resource-limited countries. Paradoxically, the cost of CD4+ T-lymphocyte count essential for decision-making to commence HIV positive adults on ART as well as for monitoring responses to ART remains unaffordable in most resource-limited countries. Thus, low-cost methods for enumerating CD4+ T-lymphocyte are urgently needed.To evaluate Cyflow cytometry (Cyflow SL, Partec, Munster, Germany) for enumeration of absolute CD4+ T-lymphocyte in subtype C HIV-1 seropositive subjects using FACSCount (Becton and Dickinson, Immunocytometry Systems, San Jose, CA, USA) as the "predicate method".A total of 150 HIV-1 seropositive subjects were included in the evaluation exercise. Fifty-eight specimens were collected from pregnant HIV-1 seropositive women (subtype C drug resistance study). Twenty-seven specimens were collected from women and their spouses with AIDS followed in a Duke ART study to assess the immunologic and virologic responses to generic ART, comprising Stavudine, Lamivudine and Nevirapine (Stalanev, Varichem Labs, Harare, Zimbabwe). Sixty-five specimens were collected from AIDS patients enrolled in an ongoing Kaposi Sarcoma (KS) study to investigate impact of ART on KS progression. Enumeration of CD4+ T-lymphocytes using FACSCount is routinely conducted for all the three studies. The Medical Research Council of Zimbabwe and Medicines Control Authority of Zimbabwe approved the studies. Whole blood was collected in EDTA vacutainer tubes and aliquoted into two tubes (200 microL in each). CD4+ T-lymphocyte counts were enumerated using a Cyflow counter, in the Department of Immunology and a FACSCount in the Department of Obstetrics and Gynaecology within 6 hours of phlebotomy following manufacturers' instructions.Using linear regression analysis, there was a very strong correlation (R = 0.991) between the overall CD4+ T-lymphocyte counts obtained by FACSCount and those obtained by Cyflow. When data analysis was stratified by study groups, there was a strong correlation between the FACSCount and Cyflow CD4+ T-lymphocyte counts from subjects in the three independent studies; Subtype C resistance (R2 = 0.987), Duke ART (R2 = 0.980) and KS (R2 = 0.994), Table 1. Using Bland-Altman plots, the overall, absolute CD4+ T lymphocytes obtained by the two methods were in excellent agreement (mean difference 1.21, 95% Confidence Interval {CI): -2.1 to 3.3). For the 0-250 CD4+ T-lymphocytes range, the CD4 counts obtained using FACSCount were also in good agreement with those obtained using Cyflow counter (mean difference = 2.6 cells/microL, 95% CI: -1.1 to 6.3). Similarly, in the 251-500 (mean difference 1.0, cells/microL, 95% CI: -3.7 to 5.6) and the 501-1200 (mean difference = 0.29 cells/microL, 95% CI: -8.1 to 8.7) CD4 T-lymphocytes range, good agreement was observed.The Cyflow counter is as accurate as the FACSCount in enumerating absolute CD4+ T-lymphocytes in the range 1-1200 cells/muL. Cyflow cytometry is relatively affordable, easy to use technology that is useful not only in identifying HIV seropositive individuals who require ART but also for monitoring immunologic responses to ART.

    View details for DOI 10.1186/1479-5876-4-33

    View details for Web of Science ID 000241031700001

    View details for PubMedID 16907973

    View details for PubMedCentralID PMC1586214

  • A pilot study evaluating time to CD4 T-cell count < 350 cells/mm(3) after treatment interruption following antiretroviral therapy +/- interleukin 2: Results of ACTG A5102 JAIDS-JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Henry, K., Katzenstein, D., Cherng, D. W., Valdez, H., Powderly, W., Vargas, M. B., Jahed, N. C., Jacobson, J. M., Myers, L. S., Schmitz, J. L., Winters, M., Tebas, P. 2006; 42 (2): 140-148

    Abstract

    Although an intermittent antiviral treatment (ART) strategy may limit long-term toxicity and cost, there is concern about the risk for virologic failure, selection of drug resistance mutations, and disease progression. By boosting CD4 T-cell counts, interleukin 2 (IL-2) could safely prolong the duration of treatment interruption (TI) in a CD4-driven strategy.The AIDS Clinical Trials Group (ACTG) study A5102 evaluated 3 cycles of IL-2 before TI, on clinical and immunologic outcomes, using a CD4 T-cell count of <350 cells/mm as the threshold for restarting ART. Forty-seven HIV-infected subjects on potent ART with CD4 T-cell counts of > or =500 cells/mm or more and HIV RNA levels of less than 200 copies/mL were randomized to arm A (ART + three 5-day cycles of IL-2 at 4.5 million U, Sc, BID every 8 weeks, n = 23) or arm B (ART alone, n = 24) for 18 weeks (step 1). At the end of step 1, subjects with a CD4 T-cell count of > or =500 cells/mm or more stopped ART until a CD4 count of <350 cells/mm (step 2). CD4 T-cell count, time to return of viremia, and the emergence of drug resistance mutations after TI were compared between study arms.IL-2 recipients maintained higher CD4 counts during TI for 48 weeks with a waning of the CD4 effect by 72 weeks. A sustained CD4 T-cell count of more than 350 cells/mm and more durable TI were associated with a higher nadir CD4 T-cell count before ART and higher naive CD4 T-cell count at entry. After TI, a higher viral set point and drug resistance mutations at virologic rebound were associated with a shorter time to CD4 T-cell count of less than 350 cell/mm. There were no differences in the magnitude of virologic rebound (at week 8 of step 2, median log10 HIV RNA level was 4.23 for arm A and 4.21 for arm B) or the steady-state HIV-1 RNA level after week 8.IL-2 before TI did not prolong time to CD4 of less than 350 cells/mm. A TI strategy utilizing a CD4 T-cell threshold of less than 350 cells/mm for restarting ART appears generally safe with most subjects in both arms remaining off ART for more than 1 year. Implications of our results for TI strategies include the potential advantage of starting ART at higher CD4 T-cell levels while avoiding any drug resistance and evaluating immunomodulators or drugs to reduce T-cell activation and HIV-1 RNA rebound during the TI.

    View details for Web of Science ID 000237910700002

    View details for PubMedID 16760795

  • Of molecules, macaques and global AIDS AIDS Katzenstein, D. A. 2006; 20 (7): 1065-1066

    View details for Web of Science ID 000237575200016

    View details for PubMedID 16603861

  • HIV-1 pol mutation frequency by subtype and treatment experience: extension of the HIVseq program to seven non-B subtypes AIDS Rhee, S. Y., Kantor, R., Katzenstein, D. A., Camacho, R., Morris, L., Sirivichayakul, S., Jorgensen, L., Brigido, L. F., Schapiro, J. M., Shafer, R. W. 2006; 20 (5): 643-651

    Abstract

    HIVseq was developed in 2000 to make published data on the frequency of HIV-1 group M protease and reverse transcriptase (RT) mutations available in real time to laboratories and researchers sequencing these genes. Because most published protease and RT sequences belonged to subtype B, the initial version of HIVseq was based on this subtype. As additional non-B sequences from persons with well-characterized antiretroviral treatment histories have become available, the program has been extended to subtypes A, C, D, F, G, CRF01, and CRF02.The latest frequency of each protease and RT mutation according to subtype and drug-class exposure was calculated using published sequences in the Stanford HIV RT and Protease Sequence Database. Each mutation was hyperlinked to published reports of viruses containing the mutation.As of September 2005, the mean number of protease sequences per non-B subtype was 534 from protease inhibitor-naive persons and 133 from protease inhibitor-treated persons, representing 13.2% and 2.3%, respectively, of the data available for subtype B. The mean number of RT sequences per non-B subtype was 373 from RT inhibitor-naive persons and 288 from RT inhibitor-treated persons, representing 17.9% and 3.8%, respectively, of the data available for subtype B.HIVseq allows users to examine protease and RT mutations within the context of previously published sequences of these genes. The publication of additional non-B protease and RT sequences from persons with well-characterized treatment histories, however, will be required to perform the same types of analysis possible with the much larger number of subtype B sequences.

    View details for Web of Science ID 000236421000002

    View details for PubMedID 16514293

  • Discordances between interpretation algorithms for genotypic resistance to protease and reverse transcriptase inhibitors of human immunodeficiency virus are subtype dependent ANTIMICROBIAL AGENTS AND CHEMOTHERAPY Snoeck, J., Kantor, R., Shafer, R. W., Van Laethem, K., Deforche, K., CARVALHO, A. P., Wynhoven, B., Soares, M. A., Cane, P., Clarke, J., Pillay, C., Sirivichayakul, S., Ariyoshi, K., Holguin, A., Rudich, H., Rodrigues, R., Bouzas, M. B., Brun-Vezinet, F., Reid, C., Cahn, P., Brigido, L. F., Grossman, Z., Soriano, V., Sugiura, W., Tanuri, A., Harrigan, R. P., Camacho, R., Schapiro, J. M., KATZENSTEIN, D., Vandamme, A. M. 2006; 50 (2): 694-701

    Abstract

    The major limitation of drug resistance genotyping for human immunodeficiency virus remains the interpretation of the results. We evaluated the concordance in predicting therapy response between four different interpretation algorithms (Rega 6.3, HIVDB-08/04, ANRS [07/04], and VGI 8.0). Sequences were gathered through a worldwide effort to establish a database of non-B subtype sequences, and demographic and clinical information about the patients was gathered. The most concordant results were found for nonnucleoside reverse transcriptase (RT) inhibitors (93%), followed by protease inhibitors (84%) and nucleoside RT inhibitor (NRTIs) (76%). For therapy-naive patients, for nelfinavir, especially for subtypes C and G, the discordances were driven mainly by the protease (PRO) mutational pattern 82I/V + 63P + 36I/V for subtype C and 82I + 63P + 36I + 20I for subtype G. Subtype F displayed more discordances for ritonavir in untreated patients due to the combined presence of PRO 20R and 10I/V. In therapy-experienced patients, subtype G displayed a lot of discordances for saquinavir and indinavir due to mutational patterns involving PRO 90 M and 82I. Subtype F had more discordance for nelfinavir attributable to the presence of PRO 88S and 82A + 54V. For the NRTIs lamivudine and emtricitabine, CRF01_AE had more discordances than subtype B due to the presence of RT mutational patterns 65R + 115 M and 118I + 215Y, respectively. Overall, the different algorithms agreed well on the level of resistance scored, but some of the discordances could be attributed to specific (subtype-dependent) combinations of mutations. It is not yet known whether therapy response is subtype dependent, but the advice given to clinicians based on a genotypic interpretation algorithm differs according to the subtype.

    View details for DOI 10.1128/AAC.50.2.694-701.2006

    View details for Web of Science ID 000235294200039

    View details for PubMedID 16436728

    View details for PubMedCentralID PMC1366873

  • A pilot study to assess the immunologic and virologic efficacy of generic nevirapine, zidovudine and lamivudine in the treatment of HIV-1 infected women with pre-exposure to single dose nevirapine or short course zidovudine and their spouses in Chitungwiza, Zimbabwe. Central African journal of medicine Zijenah, L. S., Kadzirange, G., Rusakaniko, S., KUFA, T., Gonah, N., Tobaiwa, O., Gwanzura, C., Matsikire, E., Katzenstein, D. A. 2006; 52 (1-2): 1-8

    Abstract

    A pilot study to assess effectiveness of generic Nevirapine (NVP)+Zidovudine (AZT)+Lamivudine (3TC) as potent antiretroviral therapy (ART) in women exposed to either SD NVP or short course (SC) AZT through participation in prevention of mother-to-child transmission of HIV-1 (pMTCT) interventions, and their spouses.A pilot study of antiretroviral treatment of adults with AIDS.Primary health care clinics; Seke North and St Mary's in Chitungwiza, Zimbabwe.Women with pre-exposure to SD NVP or SC AZT and their spouses with CD4 count < 200 cells/Generic AZT/3TC twice daily plus NVP daily for the first 14 days and then twice a day thereafter, administered to the cohort.The baseline median CD4 count for women and men was 128.5 and 119.0 cells/ microL respectively. The geomean virus load was similar for the women and men. At weeks 16, 24 and 48, 82.8%, 85.1% and 73.8% had < 400 copies/ml of HIV RNA respectively. Only at 16 weeks, was the proportion of women (75.9%) with undetectable virus significantly lower than that for men (93.9%), p = 0.031. Median CD4 count for both men and women increased significantly, p < 0.001. There were no significant differences in virologic responses between the women with pre-exposure to SD NVP and SC AZT. The mean adherence for women and men was similar, > 98%.Women showed a significantly reduced response top ART relative to men only at 16. However, prior exposure to SD NVP for PMTCT was no more likely to negatively influence responses to ART than use of SC AZT.

    View details for PubMedID 17892232

  • The feasibility of voluntary counselling and HIV testing for pregnant women using community volunteers in Zimbabwe 14th International AIDS Conference Shetty, A. K., Mhazo, M., Moyo, S., Von Lieven, A., Mateta, P., Katzenstein, D. A., Maldonado, Y., Hill, D., Bassett, M. T. ROYAL SOC MEDICINE PRESS LTD. 2005: 755?59

    Abstract

    The purpose of this pilot project was to assess the feasibility and acceptability of voluntary counselling and HIV testing (VCT) by pregnant women using community volunteers in Zimbabwe to prevent mother to child transmission (MTCT) of HIV. From July 1999 to June 2001, a short-course zidovudine (ZDV)-based perinatal HIV prevention programme was initiated in two antenatal clinics. Community volunteers, recruited from local community organizations, underwent a two-week training course in VCT, which included HIV/AIDS facts, systematic counselling approach, and practical counselling techniques using scripts and role-play. Rapid HIV testing was performed after informed consent. Lay counsellors conducted individual pre- and post-test counselling for HIV. A total of 35 women community volunteers were trained in VCT; 34 graduated and committed to work four hours per week in the clinic. Of the 6051 pregnant women presenting for antenatal clinics (ANC), 1824 (30%) underwent pre-test counselling and 1547 (26%) were tested, and 429 (28%) were HIV infected. Overall, 1283 (83%) returned for their test results including 406 (95%) of HIV-infected women. Of the 406 HIV-infected women who collected their test results, only 203 (50%) opted for ZDV prophylaxis to prevent MTCT of HIV. Over the two-year study period, two counsellors died and three sought employment at other organizations. Adherence to duty roster was 97% and no breach of confidentiality was reported. Despite many challenges, VCT delivered by community volunteers is feasible and acceptable for pregnant women aiming to reduce their risk of transmitting HIV to their infants. This programme is being implemented at several urban and rural MTCT sites in Zimbabwe and can serve as a model for other resource-poor countries.

    View details for PubMedID 16303072

  • Breast-milk shedding of drug-resistant HIV-1 subtype C in women exposed to single-dose nevirapine 11th Conference on Retroviruses and Opportunistic Infections Lee, E. J., Kantor, R., Zijenah, L., Sheldon, W., Emel, L., Mateta, P., Johnston, E., Wells, J., Shetty, A. K., Coovadia, H., Maldonado, Y., Jones, S. A., Mofenson, L. M., Contag, C. H., Bassett, M., Katzenstein, D. A. UNIV CHICAGO PRESS. 2005: 1260?64

    Abstract

    Single-dose nevirapine reduces intrapartum human immunodeficiency virus 1 type (HIV-1) transmission but may also select for nonnucleoside reverse-transcriptase inhibitor (NNRTI) resistance in breast milk (BM) and plasma. Among 32 Zimbabwean women, median 8-week postpartum plasma and BM HIV-1 RNA levels were 4.57 and 2.13 log(10) copies/mL, respectively. BM samples from women with laboratory-diagnosed mastitis (defined as elevated BM Na(+) levels) were 5.4-fold more likely to have HIV-1 RNA levels above the median. BM RT sequences were not obtained for 12 women with BM HIV-1 RNA levels below the lower limit of detection of the assay used. In 20 paired BM and plasma samples, 65% of BM and 50% of plasma RT sequences had NNRTI-resistance mutations, with divergent mutation patterns.

    View details for PubMedID 16136470

  • Signal-boosted qualitative ultrasensitive p24 antigen assay for diagnosis of subtype CHIV-1 infection in infants under the age of 2 years JAIDS-JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Zijenah, L. S., Tobaiwa, O., Rusakaniko, S., Nathoo, K. J., Nhembe, M., Matibe, P., Katzenstein, D. A. 2005; 39 (4): 391-394

    Abstract

    The gold standard for diagnosis of HIV-1 infection in infants under the age of 2 years is DNA or reverse transcriptase polymerase chain reaction. However, these tests are expensive and therefore not available in resource-limited countries. With the increasing availability of antiretroviral drugs for prevention of mother-to-child transmission of HIV and treatment of AIDS in resource-poor countries, there is an urgent need to develop cheaper, alternative, and cost-effective laboratory methods for early diagnosis of infant HIV-1 infection that will be useful in identifying infected infants who may benefit from early cotrimoxazole prophylaxis or commencement of antiretroviral therapy. We evaluated an alternative method, the enzyme-linked immunosorbent assay-based qualitative ultrasensitive p24 antigen assay for diagnosis of subtype C HIV-1 infection in infants under the age of 2 years using DNA polymerase chain reaction as the reference method. The assay showed a sensitivity of 96.7% (95% CI: 93.0-100) for detection of HIV-1 infection among infants 0-18 months of age with a specificity of 96.1% (95% CI: 91.7-100). These evaluated parameters were not statistically different between infants aged 0-6 and 7-18 months. The ultrasensitive p24 antigen assay is a useful diagnostic test for detection of HIV-1 infection among infants aged 0-18 months.

    View details for Web of Science ID 000230572400003

    View details for PubMedID 16010158

  • Nonnucleoside reverse transcriptase inhibitor phenotypic hypersusceptibility can be demonstrated in different assays 12th International HIV Drug Resistance Workshop Shulman, N. S., Delgado, D., Bosch, R. J., Winters, M. A., Johnston, E., Shafer, R. W., Katzenstein, D. A., Merigan, T. C. LIPPINCOTT WILLIAMS & WILKINS. 2005: 78?81

    Abstract

    HIV-1 isolates harboring multiple nucleoside reverse transcriptase inhibitor (NRTI) resistance mutations are more susceptible ("hypersusceptible") to the nonnucleoside reverse transcriptase inhibitors (NNRTIs) than isolates lacking NRTI resistance mutations, but this has only been reported with a single-cycle replication phenotypic assay. In fact, there was a report that a commercial multicycle assay did not readily detect hypersusceptibility.To see whether NNRTI hypersusceptibility can be demonstrated in other types of phenotypic assays, including multicycle assays and enzyme inhibition assays.The susceptibility of HIV-1 clones derived from different patients in multicycle assays was tested in peripheral blood mononuclear cells (PBMCs) and in an established cell line. In addition, the reverse transcriptase (RT) of many of these clones was expressed and their susceptibility tested in an RT inhibition assay. Nevirapine and efavirenz susceptibilities were tested and compared with a control wild-type virus or RT.Hypersusceptibility to nevirapine and efavirenz was detected using each of the methods described above. R values correlating the other methods with single-cycle assay values were between 0.66 and 0.96. In addition to the high correlations, the different methods gave similar numeric results.NNRTI hypersusceptibility is readily seen in multicycle susceptibility assays and in enzyme inhibition assays.

    View details for Web of Science ID 000228812000011

    View details for PubMedID 15851917

  • Impact of HIV-1 subtype and antiretroviral therapy on protease and reverse transcriptase genotype: Results of a global collaboration PLOS MEDICINE Kantor, R., Katzenstein, D. A., Efron, B., CARVALHO, A. P., Wynhoven, B., Cane, P., Clarke, J., Sirivichayakul, S., Soares, M. A., Snoeck, J., Pillay, C., Rudich, H., Rodrigues, R., Holguin, A., Ariyoshi, K., Bouzas, M. B., Cahn, P., Sugiura, W., Soriano, V., Brigido, L. F., Grossman, Z., Morris, L., Vandamme, A. M., Tanuri, A., Phanuphak, P., WEBER, J. N., Pillay, D., Harrigan, P. R., Camacho, R., Schapiro, J. M., Shafer, R. W. 2005; 2 (4): 325-337

    Abstract

    The genetic differences among HIV-1 subtypes may be critical to clinical management and drug resistance surveillance as antiretroviral treatment is expanded to regions of the world where diverse non-subtype-B viruses predominate.To assess the impact of HIV-1 subtype and antiretroviral treatment on the distribution of mutations in protease and reverse transcriptase, a binomial response model using subtype and treatment as explanatory variables was used to analyze a large compiled dataset of non-subtype-B HIV-1 sequences. Non-subtype-B sequences from 3,686 persons with well characterized antiretroviral treatment histories were analyzed in comparison to subtype B sequences from 4,769 persons. The non-subtype-B sequences included 461 with subtype A, 1,185 with C, 331 with D, 245 with F, 293 with G, 513 with CRF01_AE, and 618 with CRF02_AG. Each of the 55 known subtype B drug-resistance mutations occurred in at least one non-B isolate, and 44 (80%) of these mutations were significantly associated with antiretroviral treatment in at least one non-B subtype. Conversely, of 67 mutations found to be associated with antiretroviral therapy in at least one non-B subtype, 61 were also associated with antiretroviral therapy in subtype B isolates.Global surveillance and genotypic assessment of drug resistance should focus primarily on the known subtype B drug-resistance mutations.

    View details for DOI 10.1371/journal.pmed.0020112

    View details for PubMedID 15839752

  • Viral dynamics and CD4(+) T cell counts in subtype C human immunodeficiency virus type 1-infected individuals from southern Africa AIDS RESEARCH AND HUMAN RETROVIRUSES Gray, C. M., Williamson, C., Bredell, H., Puren, A., Xia, X. H., Filter, R., Zijenah, L., Cao, H. Y., Morris, L., Vardas, E., Colvin, M., Gray, G., McIntyre, J., Musonda, R., Allen, S., KATZENSTEIN, D., Mbizo, M., Kumwenda, N., Taha, T., Karim, S. A., Flores, J., Sheppard, H. W. 2005; 21 (4): 285-291

    Abstract

    Defining viral dynamics in natural infection is prognostic of disease progression and could prove to be important for vaccine trial design as viremia may be a likely secondary end point in phase III HIV efficacy trials. There are limited data available on the early course of plasma viral load in subtype C HIV-1 infection in Africa. Plasma viral load and CD4+ T cell counts were monitored in 51 recently infected subjects for 9 months. Individuals were recruited from four southern African countries: Zambia, Malawi, Zimbabwe, and South Africa and the median estimated time from seroconversion was 8.9 months (interquartile range, 5.7-14 months). All were infected with subtype C HIV-1 and median viral loads, measured using branched DNA, ranged from 3.82-4.02 log10 RNA copies/ml from 2-24 months after seroconversion. Viral loads significantly correlated with CD4+ cell counts (r=-0.5, p<0.0001; range, 376-364 cells/mm3) and mathematical modeling defined a median set point of 4.08 log10 (12 143 RNA copies/ml), which was attained approximately 17 months after seroconversion. Comparative measurements using three different viral load platforms (bDNA, Amplicor, and NucliSens) confirmed that viremia in subtype C HIV-1-infected individuals within the first 2 years of infection did not significantly differ from that found in early subtype B infection. In conclusion, the course of plasma viremia, as described in this study, will allow a useful baseline comparator for understanding disease progression in an African setting and may be useful in the design of HIV-1 vaccine trials in southern Africa.

    View details for Web of Science ID 000229111000005

    View details for PubMedID 15943570

  • HIV type 1 genotypic variation in an antiretroviral treatment-naive population in southern India AIDS RESEARCH AND HUMAN RETROVIRUSES Balakrishnan, P., Kumarasamy, N., Kantor, R., Solomon, S., Vidya, S., MAYER, K. H., Newstein, M., Thyagarajan, S. P., KATZENSTEIN, D., Ramratnam, B. 2005; 21 (4): 301-305

    Abstract

    Most studies of HIV-1 drug resistance have examined subtype B viruses; fewer data are available from developing countries, where non-B subtypes predominate. We determined the prevalence of mutations at protease and reverse transcriptase drug resistance positions in antiretroviral drug-naive individuals in southern India. The pol region of the genome was amplified from plasma HIV-1 RNA in 50 patients. All sequences clustered with HIV-1 subtype C. All patients had at least one protease and/or RT mutation at a known subtype B drug resistance position. Twenty percent of patients had mutations at major protease inhibitor resistance positions and 100% had mutations at minor protease inhibitor resistance positions. Six percent and 14% of patients had mutations at nucleoside reverse transcriptase inhibitor and/or nonnucleoside reverse transcriptase inhibitor resistance positions, respectively. Larger scale studies need to be undertaken to better define the genotypic variation of circulating Indian subtype C viruses and their potential impact on drug susceptibility and clinical outcome in treated individuals.

    View details for Web of Science ID 000229111000007

    View details for PubMedID 15943572

  • T lymphocytes among HIV-infected and -uninfected infants: CD4/CD8 ratio as a potential tool in diagnosis of infection in infants under the age of 2 years JOURNAL OF TRANSLATIONAL MEDICINE Zijenah, L. S., Katzenstein, D. A., Nathoo, K. J., Rusakaniko, S., Tobaiwa, O., Gwanzura, C., Bikoue, A., Nhembe, M., Matibe, P., Janossy, G. 2005; 3
  • Mapping nevirapine and efavirenz resistance using Bayesian networks of HIV-1 pol sequences of subtypes A, B, C, F and G 14th International HIV Drug Resistance Workshop Deforche, K., Camacho, R., Grossman, Z., Silander, T., Soares, M. A., Shafer, R. W., Van Laethem, K., CARVALHO, A. P., Wynhoven, B., Cane, P., Clarke, J., Snoeck, J., Sirivichayakul, S., Ariyoshi, K., Holguin, A., Rudich, H., Rodrigues, R., Bouzas, M. B., Brun-Vezinet, F., Cahn, P., Brigido, L. F., Soriano, V., Sugiura, W., Phanuphak, P., Morris, L., Weber, J., Pillay, D., Tanuri, A., Harrigan, P. R., Schapiro, J. M., KATZENSTEIN, D., Kantor, R., Vandamme, A. M. INT MEDICAL PRESS LTD. 2005: S132?S132
  • Interactions between nevirapine resistance mutations and NRTI resistance mutations 14th International HIV Drug Resistance Workshop Deforche, K., Camacho, R., Grossman, Z., Silander, T., Soares, M. A., Shafer, R. W., Van Laethem, K., CARVALHO, A. P., Wynhoven, B., Cane, P., Clarke, J., Snoeck, J., Sirivichayakul, S., Ariyoshi, K., Holguin, A., Rudich, H., Rodrigues, R., Bouzas, M. B., Brun-Vezinet, F., Cahn, P., Brigido, L. F., Soriano, V., Sugiura, W., Phanuphak, P., Morris, L., Weber, J., Pillay, D., Tanuri, A., Harrigan, P. R., Schapiro, J. M., KATZENSTEIN, D., Kantor, R., Vandamme, A. M. INT MEDICAL PRESS LTD. 2005: S144?S144
  • Selection of resistance following first-line anti-retroviral regimens among HIV-1 subtypes 14th International HIV Drug Resistance Workshop Kantor, R., DeLong, A., Shafer, R. W., CARVALHO, A. P., Wynhoven, B., Cane, P., Sirivichayakul, S., Soares, M. A., Snoeck, J., Rudich, H., Rodrigues, R., Holguin, A., Ariyoshi, K., Bouzas, M. B., Cahn, P., Sugiura, W., Soriano, V., Brigido, L. F., Grossman, Z., Morris, L., Vandamme, A. M., Tanuri, A., Phanuphak, P., Weber, J., Pillay, D., Harrigan, P. R., Camacho, R., Schapiro, J., Hogan, J., Katzenstein, D. A. INT MEDICAL PRESS LTD. 2005: S146?S146
  • Novel and promiscuous CTL epitopes in conserved regions of Gag targeted by individuals with early subtype CHIV type infection from southern Africa JOURNAL OF IMMUNOLOGY Masemola, A. M., Mashishi, T. N., Khoury, G., Bredell, H., Paximadis, M., Mathebula, T., Barkhan, D., Puren, A., Vardas, E., Colvin, M., Zijenah, L., KATZENSTEIN, D., Musonda, R., Allen, S., Kumwenda, N., Taha, T., Gray, G., McIntyre, J., Karim, S. A., Sheppard, H. W., Gray, C. M. 2004; 173 (7): 4607-4617

    Abstract

    Characterization of optimal CTL epitopes in Gag can provide crucial information for evaluation of candidate vaccines in populations at the epicenter of the HIV-1 epidemic. We screened 38 individuals with recent subtype C HIV-1 infection using overlapping consensus C Gag peptides and hypothesized that unique HLA-restricting alleles in the southern African population would determine novel epitope identity. Seventy-four percent of individuals recognized at least one Gag peptide pool. Ten epitopic regions were identified across p17, p24, and p2p7p1p6, and greater than two-thirds of targeted regions were directed at: TGTEELRSLYNTVATLY (p17, 35%); GPKEPFRDYVDRFFKTLRAEQATQDV (p24, 19%); and RGGKLDKWEKIRLRPGGKKHYMLKHL (p17, 15%). After alignment of these epitopic regions with consensus M and a consensus subtype C sequence from the cohort, it was evident that the regions targeted were highly conserved. Fine epitope mapping revealed that five of nine identified optimal Gag epitopes were novel: HLVWASREL, LVWASRELERF, LYNTVATLY, PFRDYVDRFF, and TLRAEQATQD, and were restricted by unique HLA-Cw*08, HLA-A*30/B*57, HLA-A*29/B*44, and HLA-Cw*03 alleles, respectively. Notably, three of the mapped epitopes were restricted by more than one HLA allele. Although these epitopes were novel and restricted by unique HLA, they overlapped or were embedded within previously described CTL epitopes from subtype B HIV-1 infection. These data emphasize the promiscuous nature of epitope binding and support our hypothesis that HLA diversity between populations can shape fine epitope identity, but may not represent a constraint for universal recognition of Gag in highly conserved domains.

    View details for Web of Science ID 000224072600044

    View details for PubMedID 15383595

  • Genetic correlates of efavirenz hypersusceptibility 11th Conference on Retroviruses and Opportunistic Infections Shulman, N. S., Bosch, R. J., Mellors, J. W., Albrecht, M. A., Katzenstein, D. A. LIPPINCOTT WILLIAMS & WILKINS. 2004: 1781?85

    Abstract

    Non-nucleoside reverse transcriptase inhibitor (NNRTI) hypersusceptibility is seen in approximately 30% of HIV isolates with nucleoside reverse transcriptase inhibitor (NRTI) resistance. NNRTI hypersusceptibility has been associated with improved outcomes to NNRTI-based therapy.To determine the genetic correlates of efavirenz hypersusceptibility.Paired baseline genotypes and phenotypes were obtained from 444 NRTI-experienced, NNRTI-naive patients. Fisher's exact tests, recursive partitioning (classification and regression trees; CART), and stepwise binary regression were used to identify specific reverse transcriptase (RT) mutations associated with efavirenz hypersusceptibility.In univariate analyses, 26 RT codons were associated with efavirenz hypersusceptibility (P < 0.05), the top five were 215 > 41 > 210 > 118 > 208 (all P < 0.000001). From stepwise model selection, the 215, 208 and 118 mutations remained independently predictive of efavirenz hypersusceptibility. A final binary regression model to predict efavirenz hypersusceptibility included one covariate for the 215 mutation (relative risk 2.6, P < 0.0001) and a second covariate representing either the 208 or 118 mutation (relative risk 1.8, P < 0.0001). Similarly, in a CART analysis, a mutation at codon 215 was the first split selected, followed by mutations at 208 and 118. An efavirenz hypersusceptibility genotypic score using the three mutations 208, 118 and 215 was as accurate at predicting efavirenz hypersusceptibility as a more complex scoring system using 26 mutations.Mutations at 215, 208 and 118 were independently associated with NNRTI hypersusceptibility. After confirmatory studies using other large datasets, incorporating a hypersusceptibility score into genotype interpretation algorithms will improve the prediction of NNRTI hypersusceptibility.

    View details for Web of Science ID 000223667900006

    View details for PubMedID 15316338

  • Weighted phenotypic susceptibility scores are predictive of the HIV-1 RNA response in protease inhibitor-experienced HIV-1-infected subjects 9th Conference on Retroviruses and Opportunistic Infections Swanstrom, R., Bosch, R. J., KATZENSTEIN, D., Cheng, H. L., Jiang, H. Y., Hellmann, N., Haubrich, R., Fiscus, S. A., Fletcher, C. V., Acosta, E. P., Gulick, R. M. UNIV CHICAGO PRESS. 2004: 886?93

    Abstract

    We analyzed retrospectively, by use of logistic regression, the role of the phenotypic susceptibility score (PSS) as a determinant of virologic outcome in a study of treatment-experienced human immunodeficiency virus (HIV) type 1-infected subjects. A model for PSS in which each drug was treated equally and scored as active or inactive was not predictive of HIV-1 RNA load (VL) suppression. However, weighting the potential contribution of each drug on the basis of inferred potency and by use of a continuous scale to quantify drug susceptibility revealed significant associations between PSS and outcome. Entry VL was a strong independent predictor of therapy outcome, and PSS was a strong predictor of the magnitude of the initial decrease in VL. This suggests that the prospective evaluation of PSS to identify regimens that maximize decreases in VL to reduce the probability of virologic rebound could improve antiretroviral treatment.

    View details for Web of Science ID 000223114800003

    View details for PubMedID 15295692

  • Discordances between interpretation algorithms for genotypic resistance to protease and reverse transcriptase inhibitors are subtype dependent 13th International HIV Drug Resistance Workshop Snoeck, J., Kantor, R., Shafer, R. W., Van Laethem, K., Deforche, K., CARVALHO, A. P., Wynhoven, B., Soares, M. A., Cane, P., Clarke, J., Pillay, C., Sirivichayakul, S., Ariyoshi, K., Holguin, A., Rudich, H., Rodrigues, R., Bouzas, M. B., Brun-Vezinet, F., Reid, C., Cahn, P., Brigido, L. F., Grossman, Z., Soriano, V., Sugiura, W., Phanuphak, P., Morris, L., Weber, J., Pillay, D., Tanuri, A., Harrigan, P. R., Camacho, R., Schapiro, J. M., KATZENSTEIN, D., Vandamme, A. M. INT MEDICAL PRESS LTD. 2004: U91?U92
  • Genotypic predictors of a response to didanosine monotherapy in zidovudine-experienced patients 13th International HIV Drug Resistance Workshop Delgado, J., Hughes, M., Winters, M. A., Smith, K., Merigan, T. C., Katzenstein, D. A., Shulman, N. S. INT MEDICAL PRESS LTD. 2004: U95?U95
  • d4T virtual phenotype can predict virological response to d4T monotherapy after AZT treatment, but not at the current cutoff 13th International HIV Drug Resistance Workshop Shulman, N. S., Hughes, M., Winters, M. A., Delgado, J., Merigan, T. C., Katzenstein, D. A. INT MEDICAL PRESS LTD. 2004: U94?U95
  • Evolution of resistance to drugs in HIV-1-infected patients failing antiretroviral therapy AIDS Kantor, R., Shafer, R. W., Follansbee, S., Taylor, J., Shilane, D., Hurley, L., Nguyen, D. P., KATZENSTEIN, D., Fessel, W. J. 2004; 18 (11): 1503-1511

    Abstract

    The optimal time for changing failing antiretroviral therapy (ART) is not known. It involves balancing the risk of exhausting future treatment options against the risk of developing increased drug resistance. The frequency with which new drug-resistance mutations (DRM) developed and their potential consequences in patients continuing unchanged treatment despite persistent viremia were assessed.A retrospective study of consecutive sequence samples from 106 patients at one institution with viral load (VL) of more than 400 copies/ml, with no change in ART for more than 2 months despite virologic failure.Two consecutive pol sequences, CD4 cell counts and VL were analyzed to quantify the development of new DRM and to identify changes in immunologic and virologic parameters. Genotypic susceptibility scores (GSS) and viral drug susceptibilities were calculated by a computer program (HIVDB). Poisson log-linear regression models were used to predict the expected number of mutations at the second time point.: After a median of 14 months of continued ART, 75% (80 of 106) of patients acquired new DRM and were assigned a significantly lower GSS, potentially limiting the success of future ART. The development of new DRM was proportional to the time between the two sequences and inversely proportional to the number of DRM in the first sequence. However, the development of DRM was not associated with significant changes in CD4 or VL counts.Despite stable levels of CD4 and VL over time, maintaining a failing therapeutic regimen increases drug resistance and may limit future treatment options.

    View details for DOI 10.1097/01.aids.0000131358.29586.6b

    View details for Web of Science ID 000222934500004

    View details for PubMedID 15238768

    View details for PubMedCentralID PMC2547474

  • Treatment for adult HIV infection - 2004 recommendations of the International AIDS Society-USA panel JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION Yeni, P. G., Hammer, S. M., Hirsch, M. S., Saag, M. S., Schechter, M., Carpenter, C. C., Fischl, M. A., Gatell, J. M., Gazzard, B. G., Jacobsen, D. M., Katzenstein, D. A., Montaner, J. S., Richman, D. D., Schooley, R. T., Thompson, M. A., Vella, S., Volberding, P. A. 2004; 292 (2): 251-265

    Abstract

    Substantial changes in the field of human immunodeficiency virus (HIV) treatment have occurred in the last 2 years, prompting revision of the guidelines for antiretroviral management of adults with established HIV infection.To update recommendations for physicians who provide HIV care regarding when to start antiretroviral therapy, what drugs to start with, when to change drug regimens, and what drug regimens to switch to after therapy fails.Evidence was identified and reviewed by a 16-member noncompensated panel of physicians with expertise in HIV-related basic science and clinical research, antiretroviral therapy, and HIV patient care. The panel was designed to have broad US and international representation for areas with adequate access to antiretroviral management.Evidence considered included published basic science, clinical research, and epidemiological data (identified by experts in the field or extracted through MEDLINE searches using terms relevant to antiretroviral therapy) and abstracts from HIV-oriented scientific conferences between July 2002 and May 2004.Data were reviewed to identify any information that might change previous guidelines. Based on panel discussion, guidelines were drafted by a writing committee and discussed by the panel until consensus was reached.Four antiretroviral drugs recently have been made available and have broadened the options for initial and subsequent regimens. New data allow more definitive recommendations for specific drugs or regimens to include or avoid, particularly with regard to initial therapy. Recommendations are rated according to 7 evidence categories, ranging from I (data from prospective randomized clinical trials) to VII (expert opinion of the panel).Further insights into the roles of drug toxic effects, drug resistance, and pharmacological interactions have resulted in additional guidance for strategic approaches to antiretroviral management.

    View details for Web of Science ID 000222579300031

    View details for PubMedID 15249575

  • Hierarchical targeting of subtype C human immunodeficiency virus type 1 proteins by CD8(+) T cells: Correlation with viral load JOURNAL OF VIROLOGY Masemola, A., Mashishi, T., Khoury, G., Mohube, P., Mokgotho, P., Vardas, E., Colvin, M., Zijenah, L., KATZENSTEIN, D., Musonda, R., Allen, S., Kumwenda, N., Taha, T., Gray, G., McIntyre, J., Karim, S. A., Sheppard, H. W., Gray, C. M. 2004; 78 (7): 3233-3243

    Abstract

    An understanding of the relationship between the breadth and magnitude of T-cell epitope responses and viral loads is important for the design of effective vaccines. For this study, we screened a cohort of 46 subtype C human immunodeficiency virus type 1 (HIV-1)-infected individuals for T-cell responses against a panel of peptides corresponding to the complete subtype C genome. We used a gamma interferon ELISPOT assay to explore the hypothesis that patterns of T-cell responses across the expressed HIV-1 genome correlate with viral control. The estimated median time from seroconversion to response for the cohort was 13 months, and the order of cumulative T-cell responses against HIV proteins was as follows: Nef > Gag > Pol > Env > Vif > Rev > Vpr > Tat > Vpu. Nef was the most intensely targeted protein, with 97.5% of the epitopes being clustered within 119 amino acids, constituting almost one-third of the responses across the expressed genome. The second most targeted region was p24, comprising 17% of the responses. There was no correlation between viral load and the breadth of responses, but there was a weak positive correlation (r = 0.297; P = 0.034) between viral load and the total magnitude of responses, implying that the magnitude of T-cell recognition did not contribute to viral control. When hierarchical patterns of recognition were correlated with the viral load, preferential targeting of Gag was significantly (r = 0.445; P = 0.0025) associated with viral control. These data suggest that preferential targeting of Gag epitopes, rather than the breadth or magnitude of the response across the genome, may be an important marker of immune efficacy. These data have significance for the design of vaccines and for interpretation of vaccine-induced responses.

    View details for DOI 10.1128/JVI.78.7.3233-3243.2004

    View details for Web of Science ID 000220293600004

    View details for PubMedID 15016844

    View details for PubMedCentralID PMC371059

  • Sex-based differences in saquinavir pharmacology and virologic response in AIDS Clinical Trials Group study 359 2nd International-AIDS-Society Conference on HIV Pathogenesis and Treatment Fletcher, C. V., Jiang, H. Y., Brundage, R. C., Acosta, E. P., Haubrich, R., KATZENSTEIN, D., Gulick, R. M. OXFORD UNIV PRESS INC. 2004: 1176?84

    Abstract

    AIDS Clinical Trials Group study 359 was a controlled study of saquinavir with either ritonavir or nelfinavir, together with delavirdine, adefovir, or both, in indinavir-experienced persons. Saquinavir was common in all study arms, and the study investigated relationships among characteristics of patients, saquinavir area under the curve (AUC) and trough concentrations (C(min)), and virologic response. Concentrations of saquinavir were higher when it was combined with ritonavir than when it was combined with nelfinavir and were lower with adefovir-containing regimens. Females had higher AUC and C(min) values than did males. Higher saquinavir AUC and C(min) values were associated with a greater likelihood of human immunodeficiency virus (HIV) RNA levels

    View details for Web of Science ID 000220338200007

    View details for PubMedID 15031785

  • The longer the better? Four years of durable, initially boosted protease treatment. AIDS Katzenstein, D. 2004; 18 (5): 811-813

    View details for PubMedID 15075518

  • Mycobacterium tuberculosis/HIV-1 coinfection and disease: Role of human leukocyte antigen variation 13th International Congress of Histocompatibility and Immunogenetics Louie, L. G., Hartogensis, W. E., Jackman, R. P., Schultz, K. A., Zijenah, L. S., Yiu, C. H., Nguyen, V. D., Sohsman, M. Y., Katzenstein, D. K., Mason, P. R. UNIV CHICAGO PRESS. 2004: 1084?90

    Abstract

    Genetic variation influences immune responses and may contribute to differential development of tuberculosis (TB), particularly in immunosuppressed individuals. To examine the risk of Mycobacterium tuberculosis infection progressing to disease in the context of M. tuberculosis/human immunodeficiency virus (HIV) type 1 coinfection, HIV-1 RNA load and human leukocyte antigen (HLA) genotypes were determined among subjects from Harare, Zimbabwe, an area where both TB and HIV-1 are endemic. Patients with TB were compared with control subjects, stratified by HIV-1 infection status and progression of TB disease. Alleles of class I HLA-A and -C were associated with risk of developing active TB, depending on HIV-1 status. Among HIV-positive subjects, HIV-1 load was independently associated with increased risk of developing pulmonary TB. HLA DRB1 homozygosity among HIV-positive subjects was associated with reduced risk of developing pulmonary TB but increased risk of rapid progression to pleural effusion TB. These observations suggest that HLA plays a role in risk of developing symptomatic TB at various stages of disease and that these effects are modified by HIV-1 coinfection.

    View details for Web of Science ID 000220001100016

    View details for PubMedID 14999612

  • Drug resistance in non-subtype BHIV-1 JOURNAL OF CLINICAL VIROLOGY Kantor, R., KATZENSTEIN, D. 2004; 29 (3): 152-159

    Abstract

    Treatment of HIV-1 with antiretroviral therapy may select mutations in the pol gene associated with resistance to reverse transcriptase inhibitors and protease inhibitors. To provide durable clinical benefit, emergence of drug resistance is countered by prescription of alternative drug regimens. Data on sequential treatments that are effective after virologic failure and the selection of drug resistance is largely confined to HIV-1 subtype B, the clade that has circulated in North America and Europe. However, HIV-1 subtype B currently accounts for only 12% of the estimated 40 million HIV infected individuals worldwide. The global HIV-1 epidemic includes infection with nine identified HIV-1 group M subtypes (A-K), as well as distinct sub-subtypes and numerous chimerical or recombinant forms. Increasing access to treatment of HIV-1 in the developing world and increasing non-subtype B infection through travel and migration pose new questions about the susceptibility and response of these diverse HIV-1 viruses to antiretroviral drugs. Here we review HIV diversity and the published literature on drug resistance, comparing the known resistance mutations in individuals infected with subtype B to the growing experience in the treatment of non-subtype B HIV-1 worldwide.

    View details for DOI 10.1016/S1386-6532(03)00115-X

    View details for Web of Science ID 000189219300002

    View details for PubMedID 14962783

  • Infant feeding practices of HIV-infected and uninfected women in Zimbabwe 13th International AIDS Conference GOTTLIEB, D., Shetty, A. K., Mapfungautsi, R. M., Bassett, M. T., Maldonado, Y., Katzenstein, D. A. MARY ANN LIEBERT INC. 2004: 45?53

    Abstract

    We surveyed infant feeding knowledge, attitudes, and practices in Zimbabwe to determine whether knowledge of HIV seropositivity influences infant feeding behavior. Questionnaires were administered to 97 women 1 and 4 weeks postpartum and prospective data on infant feeding practices were collected. Participants were pregnant women who consented to a HIV test. A total of 116 women participated of whom 99 women underwent voluntary HIV counseling and testing (VCT); 17 women agreed to blinded HIV testing but did not opt for VCT. The responses to questionnaires on infant feeding practices of HIV-positive and HIV-negative women who knew and did not know their HIV status at day 1 and week 4 postpartum were compared. We found that HIV-positive women who did not learn their status breastfed their infants less, introduced supplementary foods sooner, and planned to wean their babies earlier compared to other women (p = 0.005, p = NS, p= 0.02). HIV-positive women (30/97) more frequently reported a prior history of infant death and AIDS-related symptoms compared to HIV-negative women. We conclude that HIV-positive women who did not know their status made incorrect decisions with respect to infant feeding. These women may have suspected themselves to be HIV-positive and consequently underfed their infants or because these women were more symptomatic may have been less likely to breastfeed; decreased intake may increase the risk for malnutrition. Knowledge of HIV status may influence infant feeding decisions and reveal an urgent need to address infant feeding practices of pregnant women in Zimbabwe.

    View details for Web of Science ID 000188416500007

    View details for PubMedID 15006194

  • Safety and Trough Concentrations of Nevirapine Prophylaxis Given Daily, Twice Weekly, or Weekly in Breast-Feeding Infants From Birth to 6 Months JAIDS-JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Shetty, A. K., Coovadia, H. M., Mirochnick, M. M., Maldonado, Y., Mofenson, L. M., Eshleman, S. H., Fleming, T., Emel, L., George, K., Katzenstein, D. A., Wells, J., Maponga, C. C., Mwatha, A., Jones, S. A., Karim, S. S., Bassett, M. T. 2003; 34 (5): 482-490

    Abstract

    Despite the success of antiretroviral prophylaxis in reducing mother-to-child HIV-1 transmission, postpartum transmission through breast milk remains a problem. Antiretroviral administration to the infant during the period of breast-feeding could protect against postnatal transmission. An open-label phase 1/2 study was designed to assess the safety and trough concentrations of nevirapine (NVP) given once weekly (OW), twice weekly (TW), or once daily (OD) to HIV-exposed breast-feeding infants for 24 weeks. Following maternal dosing with 200 mg NVP orally at onset of labor, breast-feeding infants were randomized within 48 hours of birth to 1 of 3 regimens: arm 1, NVP given OW (4 mg/kg from birth to 14 days, upward arrow to 8 mg/kg from 15 days to 24 weeks), arm 2, NVP given TW (4 mg/kg from birth to 14 days, upward arrow to 8 mg/kg from 15 days to 24 weeks), and arm 3, NVP given OD (2 mg/kg from birth to 14 days, upward arrow to 4 mg/kg from 15 days to 24 weeks). Trough NVP concentrations and clinical and laboratory abnormalities were monitored. Of the 75 infants randomized (26 to OW, 25 to TW, and 24 to OD dosing), 63 completed the 32-week follow-up visit. No severe skin, hepatic, or renal toxicity related to NVP was observed. Neutropenia occurred in 8 infants. Trough NVP levels were lower than the therapeutic target (100 ng/mL) in 48 of 75 (64.0%) samples from infants in the OW arm, 3 of 65 (4.6%) samples in the TW arm, and 0 of 72 samples in the OD arm. Median (range) trough NVP concentrations were 64 ng/mL (range: <25-1519 ng/mL) with OW dosing; 459 (range: <25-1386 ng/mL) with TW dosing; and 1348 (range: 108-4843 ng/ml) with OD dosing. Our data indicate that NVP prophylaxis for 6 months was safe and well tolerated in infants. OD NVP dosing resulted in all infants with trough concentration greater than the therapeutic target and maintenance of high drug concentrations. A phase 3 study is planned to assess the efficacy of OD infant NVP regimen to prevent breast-feeding HIV-1 transmission.

    View details for PubMedID 14657758

  • Evaluation of cutpoints for phenotypic hypersusceptibility to efavirenz AIDS Bosch, R. J., Downey, G. F., Katzenstein, D. A., Hellmann, N., Bacheler, L., Albrecht, M. A. 2003; 17 (16): 2395-2396
  • HIV/AIDS care and treatment in sub-Saharan Africa. AIDS reviews Kassaye, S. G., Katzenstein, D. 2003; 5 (4): 195-204

    Abstract

    Antiretroviral (ARV) drugs have become the cornerstone of care and treatment for AIDS in North America, Brazil, and Europe. Twenty years into the epidemic, and more than 10 years after the introduction of ARV's, effective global treatment of AIDS, particularly in sub-Saharan Africa where the epidemic is most concentrated, is an extraordinary challenge. Guidelines and experience in anti-microbial prophylaxis, prescription and monitoring of ARV's in resource-rich countries should inform the efforts to scale-up AIDS care and treatment in Africa. Here, we review the considerable experience of ARV treatment acquired largely in the Americas and Europe, and the fledgling clinical trials and observational studies in Africa. Implementation of safe, effective, and equitable access to ARV's in Africa should be cognizant of the guidelines for ARV treatment in the Northern countries. Careful observation and operational research to accrue more African data, and evaluate regional and local solutions to this daunting challenge, will identify new approaches to scaling-up of ARV treatment.

    View details for PubMedID 15011998

  • Assessing resistance costs of antiretroviral therapies via measures of future drug options 11th International Workshop on HIV Drug Resistance and Treatment Strategies Jiang, H. Y., Deeks, S. G., Kuritzkes, D. R., Lallemant, M., KATZENSTEIN, D., Albrecht, M., DeGruttola, V. OXFORD UNIV PRESS INC. 2003: 1001?8

    Abstract

    The emergence of drug-resistant human immunodeficiency virus (HIV) type 1 in the setting of antiretroviral therapy failure limits the number of drugs available for use in subsequent therapy regimens. To quantify the relative HIV-1-resistance costs associated with various antiretroviral therapy strategies, we developed 2 related measures of future drug options (FDOs) by use of rule-based genotype-interpretation systems. The FDO1 metric assesses the number of drug classes that remain useful; the FDO2 metric assesses the number of drug classes that remain useful and the number of active drugs within each class. Application of these methods is illustrated with data from a randomized study of 3 therapy regimens in nucleoside analog-experienced patients. Each therapy regimen resulted in a unique pattern of drug-resistance (and cross-resistance) mutations. The regimen with the highest virologic failure rate preserved greater future drug options. Quantification of future drug options as an outcome of antiretroviral therapy trials may complement traditional clinical, virologic, and immunologic end points, thereby providing novel insights.

    View details for Web of Science ID 000185593900010

    View details for PubMedID 14513420

  • Genotype, phenotype, and virtual phenotype: who needs what and why? Journal of the International Association of Physicians in AIDS Care (Chicago, Ill. : 2002) Katzenstein, D. A. 2003; 2 (4): 140-146

    View details for PubMedID 14986515

  • Clinical impact of the M184V mutation on switching to didanosine or maintaining lamivudine treatment in nucleoside reverse-transcriptase inhibitor-experienced patients 11th International Workshop on HIV Drug Resistance and Treatment Strategies Winters, M. A., Bosch, R. J., Albrecht, M. A., Katzenstein, D. A. UNIV CHICAGO PRESS. 2003: 537?40

    Abstract

    Virologic outcome among 104 lamivudine (3TC)-experienced individuals infected with human immunodeficiency virus type 1 who switched to a didanosine (ddI)-containing triple- or quadruple-drug regimen was compared with those who continued receiving a 3TC-containing regimen. A significantly increased independent risk of virologic failure was associated with continuing a 3TC-containing regimen. In addition, most patients for whom the ddI-containing regimen failed lost the M184V/I mutation. These results show that ddI continues to provide activity against viruses with the M184V/I mutation and suggest that the presence of the M184V/I mutation should not preclude the use of ddI in nucleoside-experienced patients.

    View details for Web of Science ID 000184567000008

    View details for PubMedID 12898440

  • High frequency of syncytium-inducing and CXCR4-tropic viruses among human immunodeficiency virus type 1 subtype C-infected patients receiving antiretroviral treatment JOURNAL OF VIROLOGY Johnston, E. R., Zijenah, L. S., Mutetwa, S., Kantor, R., Kittinunvorakoon, C., Katzenstein, D. A. 2003; 77 (13): 7682-7688

    Abstract

    Human immunodeficiency virus type 1 (HIV-1) subtype C viruses have been found to almost exclusively use the chemokine receptor CCR5 as a coreceptor for entry, even in patients with advanced AIDS. We have characterized subtype C virus isolates from 28 patients from Harare, Zimbabwe, 20 of whom were receiving antiretroviral treatment. Virus from 10 of the treated patients induced syncytium formation (SI virus) when cultured with MT2 cells. Only non-syncytium-inducing (NSI) virus was cultured from the peripheral blood mononuclear cells of the eight patients who had not received treatment. The majority of these subtype C SI viruses were capable of using both CCR5 and CXCR4 as coreceptors for viral entry, and the consensus V3 loop sequences from the SI viruses displayed a high net charge compared to those of NSI viruses. While those on treatment had reverse transcriptase (RT) and protease mutations, there was no clear association between RT and protease drug resistance mutations and coreceptor tropism. These results suggest that CXCR4-tropic viruses are present within the quasispecies of patients infected with subtype C virus and that antiretroviral treatment may create an environment for the emergence of CXCR4 tropism.

    View details for DOI 10.1128/JVI.77.13.7682-7688.2003

    View details for Web of Science ID 000183598600057

    View details for PubMedID 12805470

    View details for PubMedCentralID PMC164829

  • The evaluation of the HIV/AIDS Drug Access Initiatives in Cote D'Ivoire, Senegal and Uganda: how access to antiretroviral treatment can become feasible in Africa AIDS KATZENSTEIN, D., Laga, M., Moatti, J. P. 2003; 17: S1-S4

    View details for Web of Science ID 000184785700001

    View details for PubMedID 14565603

  • Non-nucleoside reverse transcriptase inhibitor hypersusceptibility can be demonstrated in multicycle phenotype assays and in inhibition assays of purified HIV-1 reverse transcriptases 12th International HIV Drug Resistance Workshop Shulman, N. S., Delgado, J., Winters, M. A., Johnston, E., Katzenstein, D. A., Shafer, R. W., Merigan, T. INT MEDICAL PRESS LTD. 2003: U50?U51
  • Rapid flux in non-nucleoside reverse transcriptase inhibitor resistance mutations among subtype CHIV-1-infected women after single dose nevirapine 12th International HIV Drug Resistance Workshop Kantor, R., Lee, E., Johnston, E., Mateta, P., Zijenah, L., Maldonado, Y., KATZENSTEIN, D. INT MEDICAL PRESS LTD. 2003: U78?U79
  • Nucleic acid differences between HIV-1 non-B and B reverse transcriptase and protease sequences at drug resistance positions 12th International HIV Drug Resistance Workshop Kantor, R., CARVALHO, A. P., Wynhoven, B., Soares, M. A., Cane, P., Clarke, J., Snoeck, J., Pillay, C., Sirivichayakul, S., Ariyoshi, K., Holguin, A., Rudich, H., Rodrigues, R., Bouzas, M. B., Cahn, P., Brigido, L. F., Grossman, Z., Soriano, V., Sugiura, W., Phanuphak, P., Morris, L., Vandamme, A. M., Weber, J., Pillay, D., Tanuri, A., Harrigan, P. R., Camacho, R., Schapiro, J. M., Shafer, R. W., KATZENSTEIN, D. INT MEDICAL PRESS LTD. 2003: U58?U59
  • Comparison of five interpretation algorithms for the prediction of protease inhibitor susceptibility in HIV-1 non-B subtypes 12th International HIV Drug Resistance Workshop Snoeck, J., Kantor, R., Shafer, R. W., Derdelinckx, I., CARVALHO, A. P., Wynhoven, B., Soares, M. A., Cane, P., Clarke, J., Pillay, C., Sirivichayakul, S., Ariyoshi, K., Holguin, A., Rudich, H., Rodrigues, R., Bouzas, M. B., Van Laethem, K., Brun-Vezinet, F., Reid, C., Cahn, P., Brigido, L. F., Grossman, Z., Soriano, V., Sugiura, W., Phanuphak, P., Morris, L., Weber, J., Pillay, D., Tanuri, A., Harrigan, P. R., Camacho, R., Schapiro, J. M., KATZENSTEIN, D., Vandamme, A. M. INT MEDICAL PRESS LTD. 2003: U98?U99
  • Phenotypic susceptibility and virological outcome in nucleoside-experienced patients receiving three or four antiretroviral drugs AIDS Katzenstein, D. A., Bosch, R. J., Hellmann, N., Wang, N., Bacheler, L., Albrecht, M. A. 2003; 17 (6): 821-830

    Abstract

    To evaluate phenotypic drug susceptibility and non-nucleoside reverse transcriptase inhibitor hypersusceptibility as predictors of the time to virological failure.In a randomized clinical trial, phenotypic susceptibility was retrospectively determined among 131 exclusively nucleoside reverse transcriptase inhibitor (NRTI)-experienced patients with baseline HIV-RNA levels greater than 2000 copies/ml. Subjects were assigned two NRTI drugs and were randomly assigned to nelfinavir, efavirenz, or both. Virological failure was defined as two HIV-RNA measurements of 2000 copies/ml or greater at or after week 16 and before treatment discontinuation.Using biological cut-offs to define resistance, assigned NRTI and randomized drug regimens, continuous and dichotomous phenotypic susceptibility scores (PSS) were calculated for each virus. Efavirenz hypersusceptibility as a dichotomous value was defined as less than 0.4-fold resistance. Associations between virological failure and continuous and dichotomous PSS were evaluated using Kaplan-Meier curves and Cox proportional hazards regression models.A higher baseline viral load (P < 0.02) and lower dichotomous or continuous baseline PSS (P = 0.004 and P < 0.001, respectively) were independently associated with virological failure. In the 85 subjects who received efavirenz, efavirenz hypersusceptibility (P = 0.042, hazard ratio 0.43, 95% confidence interval 0.19-0.97) was independently associated with a reduced risk of virological failure.Reduced phenotypic susceptibility was a significant independent risk factor for virological failure. The presence of efavirenz hypersusceptibility appeared to enhance virological responses during treatment with efavirenz in combination with NRTIs. The retrospective calculation of continuous PSS accurately identified treatment regimens containing sufficient drug activity to prevent virological failure.

    View details for DOI 10.1097/01.aids.0000050869.71999.40

    View details for Web of Science ID 000182779700009

    View details for PubMedID 12660529

  • Polymorphism in HIV-1 non-subtype B protease and reverse transcriptase and its potential impact on drug susceptibility and drug resistance evolution. AIDS reviews Kantor, R., Katzenstein, D. 2003; 5 (1): 25-35

    Abstract

    HIV-1 non-subtype B viruses are predominant worldwide. At least 9 different HIV-1 group M subtypes and 14 circulating recombinant forms differ from one another by 10-15% in their pol gene, which includes the coding regions for the viral protease and reverse transcriptase (RT), the current targets of antiretroviral drugs. Inter-subtype genotypic diversity includes polymorphism at amino acid residues known to be related to drug resistance in HIV-1 subtype B. Whether polymorphism alters protease and RT function, drug susceptibility, or clinical response to treatment, is unclear. Worldwide dissemination of non-subtype B viruses and increasing availability of antiretroviral drugs in the developing world will expand drug use and the likelihood of drug resistance in non-subtype B viruses. In this review we define and characterize inter-subtype RT and protease polymorphism, and examine the evidence for genotypic and phenotypic differences between HIV-1 subtypes as well as the potential for different clinical responses and evolution of drug resistance among non-B infected individuals.

    View details for PubMedID 12875105

  • Prognostic value of baseline human immunodeficiency virus type 1 DNA measurement for disease progression in patients receiving nucleoside therapy JOURNAL OF INFECTIOUS DISEASES Tierney, C., Lathey, J. L., Christopherson, C., Bettendorf, D. M., D'Aquila, R. T., Hammer, S. M., Katzenstein, D. A. 2003; 187 (1): 144-148

    Abstract

    Human immunodeficiency virus (HIV) type 1 DNA assay data were obtained at baseline from 111 HIV-1-positive subjects who were treated with nucleosides. Higher baseline DNA level, HIV-1 RNA level, and infectious titer were comparably associated with an increased hazard of disease progression (each P<.03). Only DNA level was significantly associated with survival (adjusted hazard ratio for 1 log(10) higher level, 3.99; 95% confidence interval, 1.44-11.09; P=.008).

    View details for Web of Science ID 000179809900021

    View details for PubMedID 12508159

  • HIV-1 subtype C reverse transcriptase and protease genotypes in Zimbabwean patients failing antiretroviral therapy AIDS RESEARCH AND HUMAN RETROVIRUSES Kantor, R., Zijenah, L. S., Shafer, R. W., Mutetwa, S., Johnston, E., Lloyd, R., Von Lieven, A., Israelski, D., Katzenstein, D. A. 2002; 18 (18): 1407-1413

    Abstract

    HIV-1 drug resistance mutations have been identified and characterized mostly in subtype B HIV-1 infection. The extent to which antiretroviral drugs select for drug resistance mutations in non-subtype B HIV-1 is not known. We obtained HIV-1 reverse transcriptase (RT) and protease sequences from 21 Zimbabwean patients failing antiretroviral drug therapy. We compared these sequences with 56 published RT and protease subtype C sequences from untreated patients, 990 RT and 1140 protease subtype B sequences from treated patients, and 340 RT and 907 protease subtype B sequences from untreated patients and identified four mutation categories of subtype C HIV-1. Seventeen of the 21 patients (81%) had known drug resistance mutations. Mutations at 15 RT and 11 protease positions were more common in subtype C isolates than in subtype B isolates. HIV-1 subtype C-infected individuals receiving antiretroviral therapy develop many of the known subtype B drug resistance mutations. Comparison of subtype C RT and protease sequences with a large database of subtype B sequences identified subtype C-specific polymorphisms and candidate drug resistance mutations.

    View details for Web of Science ID 000179813400009

    View details for PubMedID 12512512

  • Association of high HIV-1 RNA levels and homozygosity at HLA class II DRB1 in adults coinfected with Mycobacterium tuberculosis in Harare, Zimbabwe HUMAN IMMUNOLOGY Zijenah, L. S., Hartogensis, W. E., Katzenstein, D. A., Tobaiwa, O., Mutswangwa, J., Mason, P. R., Louie, L. G. 2002; 63 (11): 1026-1032

    Abstract

    HIV-1 mRNA levels (virus load) were quantified for 191 pulmonary tuberculosis (TB) patients and 132 HIV-1 seropositive controls. Human leukocyte antigen (HLA) class I and II genes were typed for 188 patients and 121 HIV-1 seropositive controls. The mean log virus load was higher among cases than HIV-1 seropositive controls (p < 0.0001). Among the controls, mean log virus load was higher among males than females (p = 0.04). There was no association between virus load and homozygosity at HLA class I and II among the controls. In contrast, among the cases, HLA-DRB1 homozygosity was associated with high virus load (p = 0.008), conferring risk for rapid progression to AIDS, thus lending support to the heterozygote advantage hypothesis. The observed decreased virus load in HLA-DRB-1 heterozygotes may be due to a better control of M. tb. infection in the context of HIV-1 disease.

    View details for Web of Science ID 000178924200007

    View details for PubMedID 12392855

  • Subtle decreases in stavudine phenotypic susceptibility predict poor virologic response to stavudine monotherapy in zidovudine-experienced patients 1st IAS Conference on HIV Pathogenesis and Treatment Shulman, N. S., Hughes, M. D., Winters, M. A., Shafer, R. W., Zolopa, A. R., Hellmann, N. S., Bates, M., Whitcomb, J. M., Katzenstein, D. A. LIPPINCOTT WILLIAMS & WILKINS. 2002: 121?27

    Abstract

    To identify the level of phenotypic susceptibility for stavudine (d4T) that is associated with a diminished virologic response to d4T therapy, phenotyping was performed on archived baseline HIV isolates from 26 subjects who received d4T monotherapy in AIDS Clinical Trials Group (ACTG) 302 who had received >3 years of prior zidovudine (ZDV) monotherapy. Seven of 26 subjects achieved a virologic response of >0.3-log10 copies/mL reduction in plasma HIV RNA after 8 weeks of d4T. Responders had lower fold changes in susceptibility to d4T (1.0 vs. 1.6, p=.003), lower baseline viral loads (4.26 vs. 4.74 log10 copies/mL, p=.004), and fewer thymidine analog mutations (TAMS) (1 vs. 2, p=.059). Lower baseline d4T fold change in susceptibility predicted greater reductions in HIV RNA from baseline to week 8 after adjusting for baseline HIV RNA, ZDV fold change in susceptibility, and number of TAMS. Using the same phenotypic assay, drug susceptibility among 240 antiretroviral-naive patients found all HIV isolates to have d4T susceptibility

    View details for DOI 10.1097/01.QAI.0000038335.74605.52

    View details for Web of Science ID 000178884500001

    View details for PubMedID 12394789

  • Durability of response to treatment among antiretroviral-experienced subjects: 48-week results from AIDS Clinical Trials Group Protocol 359 7th Conference on Retroviruses and Opportunistic Infections Gulick, R. M., Hu, X. J., Fiscus, S. A., Fletcher, C. V., Haubrich, R., Cheng, H. L., Acosta, E., Lagakos, S. W., Swanstrom, R., Freimuth, W., Snyder, S., Mills, C., Fischl, M., Pettinelli, C., KATZENSTEIN, D. UNIV CHICAGO PRESS. 2002: 626?33

    Abstract

    The 24-week extension of AIDS Clinical Trials Group Protocol 359, a study of human immunodeficiency virus (HIV)-infected, indinavir-experienced patients, was designed to study the durability of "salvage" treatment regimens. Patients received saquinavir in combination with either ritonavir or nelfinavir and, in addition, delavirdine, adefovir, or both. Patients who demonstrated a virologic response at weeks 12-16 were eligible to continue therapy in the extension through week 48. Of the 105 eligible subjects who were enrolled in the extension, 86 (82%) completed 48 weeks, and 49 (57%) of those 86 had HIV RNA levels

    View details for Web of Science ID 000177352900006

    View details for PubMedID 12195349

  • Antiretroviral treatment for adult HIV infection in 2002 - Updated recommendations of the international AIDS Society-USA panel JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION Yeni, P. G., Hammer, S. M., Carpenter, C. C., Cooper, D. A., Fischl, M. A., Gatell, J. M., Gazzard, B. G., Hirsch, M. S., Jacobsen, D. M., Katzenstein, D. A., Montaner, J. S., Richman, D. D., Saag, M. S., Schechter, M., Schooley, R. T., Thompson, M. A., Vella, S., Volberding, P. A. 2002; 288 (2): 222-235

    Abstract

    New information warrants updated recommendations for the 4 central issues in antiretroviral therapy: when to start, what drugs to start with, when to change, and what to change to. These updated recommendations are intended to guide practicing physicians actively involved in human immunodeficiency virus (HIV)- and acquired immunodeficiency syndrome (AIDS)-related care.In 1995, physicians with specific expertise in HIV-related basic science and clinical research, antiretroviral therapy, and HIV patient care were invited by the International AIDS Society-USA to serve on a volunteer panel. In 1999, others were invited to broaden international representation. The 17-member panel met regularly in closed meetings between its last report in 2000 and April 2002 to review current data. The effort was sponsored and funded by the International AIDS Society-USA, a not-for-profit physician education organization.The full panel was convened in late 2000 and assigned 7 section committees. A section writer and 3 to 5 section committee members (each panel member served on numerous sections) identified relevant evidence and prepared draft recommendations. Basic science, clinical research, and epidemiologic data from the published literature and abstracts from recent (within 2 years) scientific conferences were considered by strength of evidence. Extrapolations from basic science data and expert opinion of the panel members were included as evidence. Draft sections were combined and circulated to the entire panel and discussed in a series of full-panel conference calls until consensus was reached. Final recommendations represent full consensus agreement of the panel.Because of increased awareness of the activity and toxicity of current drugs, the threshold for initiation of therapy has shifted to a later time in the course of HIV disease. However, the optimal time to initiate therapy remains imprecisely defined. Availability of new drugs has broadened options for therapy initiation and management of treatment failure, which remains a difficult challenge.

    View details for Web of Science ID 000176711100023

    View details for PubMedID 12095387

  • A phase I, placebo-controlled trial of multi-dose recombinant human interleukin-12 in patients with HIV infection AIDS Jacobson, M. A., Spritzler, J., Landay, A., Chan, E., KATZENSTEIN, D., Schock, B., Fox, L., Roe, J., Kundu, S., Pollard, R. 2002; 16 (8): 1147-1154

    Abstract

    Interleukin (IL)-12 is a cytokine that stimulates T lymphocytes and natural killer cells to generate a Type 1 T-helper lymphocyte immune response. The primary objective of this study was to determine the safety and immunologic activity of repeated recombinant human IL-12 (rhIL-12) dosing in HIV-infected patients over a broad range of the HIV disease spectrum.A randomized, placebo-controlled, Phase 1 trial design was chosen to control for the effects of HIV disease alone on safety and immunologic measurements.HIV-infected patients on antiretroviral therapy received rhIL-12 or placebo twice weekly for 4 weeks. Subjects were monitored for safety and changes in absolute lymphocyte subset number, serum interferon (IFN)gamma and neopterin levels, plasma HIV RNA level, peripheral blood mononuclear cell (PBMC)-inducible IFNgamma responses to mitogen, and PBMC proliferative responses to phytohemagglutinin, tetanus, Candida, Mycobacterium avium complex, streptokinase, and HIV p24 and gp160 antigens.rhIL-12 was well tolerated at doses up to 100 ng/kg in subjects enrolled with CD4 cell counts < 50 x 10(6) cells/l and at all doses in subjects with CD4 cell counts of 300 x 10(6)-500 x 10(6) cells/l. rhIL-12 resulted in dose-related increases in serum neopterin (particularly in subjects with baseline CD4 cell counts of 300-500 x 10(6) cells/l) but in no significant changes in other immunologic measurements or plasma HIV RNA levels.rhIL-12 dosed twice weekly at < or = 100 ng/kg was well tolerated in HIV-infected patients and resulted in dose-related increases in serum neopterin (possibly reflecting the effect of some degree of IFNgamma induction). However, there was no evidence of improvement in antigen-specific immune response.

    View details for Web of Science ID 000175760600008

    View details for PubMedID 12004273

  • Clinical signs and symptoms in the assessment of immunodeficiency in men with subtype C HIV infection in Harare, Zimbabwe. HIV clinical trials Machekano, R., Bassett, M., McFarland, W., Katzenstein, D. 2002; 3 (2): 148-154

    Abstract

    Providing low-cost interventions such as co-trimoxazole as prophylaxis against opportunistic infections among HIV-infected individuals depends on the identification of those at risk. This article describes the prevalence of self-reported signs and symptoms and CD4 cell counts in a cohort of 447 HIV seropositive men. A scoring system using self-reported signs and symptoms was developed and tested in the prediction of low CD4 cell counts. This approach may allow health care providers in low-resource settings to predict severe immunodeficiency and to provide care.Data on clinical manifestations of HIV infection and blood samples for HIV serology were collected prospectively from an ambulatory cohort of men seen at their workplace at enrollment and every 6 months thereafter. CD4+ cell counts were obtained on samples testing positive on ELISA. Using data reduction techniques and logistic modeling, we developed a prognostic score system.20% of the men had CD4+ cell counts below 200. All reported signs and symptoms were more frequent in men with less than 200 CD4+ cell counts compared to men with CD4+ cell counts greater than 200. History of malaria, fever, lymphadenopathy, persistent diarrhea, persistent cough, and skin infections robustly predicted low CD4+ count. A scoring system equation was developed based on the coefficients of the multivariate logistic regression: 1x(tuberculosis) + 3.2x(herpes zoster) + 4.5x(malaria) + 5.7x(fever) + 5.8x(cough) + 8.2x(lymphadenopathy) + 8.5x(skin infection). Setting the score cutoff value greater than or equal 5, the model had moderately high sensitivity of 61% and specificity of 72%. The scoring system had an overall classification error rate of 30%.By using this simple scoring system, physicians can correctly identify 72% of patients who do not require immediate intervention, thereby channeling scarce resources to those who have both low CD4+ cell counts and symptoms and are most likely to benefit from prophylactic and antiretroviral interventions.

    View details for PubMedID 11976993

  • Clinical impact of the M184V mutation on switching to didanosine or maintaining lamivudine treatment in nucleoside-experienced patients Winters, M. A., Bosch, R. J., Albrecht, M. A., Katzenstein, D. A. INT MEDICAL PRESS LTD. 2002: S134?S134
  • Evolution of protease phenotype and genotype changes at initial and continued virological failure among nucleoside-experienced subjects receiving nelfinavir in ACTG 364 KATZENSTEIN, D., Downey, G., Bosch, R., Hellmann, N., Becker, M., Albrecht, M. INT MEDICAL PRESS LTD. 2002: S156?S156
  • Genotypic correlates of a virologic response to stavudine after zidovudine monotherapy JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Shulman, N. S., Machekano, R. A., Shafer, R. W., Winters, M. A., Zolopa, A. R., Liou, S. H., Hughes, M., Katzenstein, D. A. 2001; 27 (4): 377-380

    Abstract

    Prior evidence suggests that resistance to zidovudine (ZDV) confers some degree of cross-resistance to stavudine (d4T), but no genotypic correlates of clinical d4T susceptibility and resistance exist. To identify the genotypic correlates of a virologic response to d4T, reverse transcriptase (RT) sequencing of archived plasma HIV isolates was performed on 31 subjects who received d4T monotherapy in the AIDS Clinical Trials Group 302 study, all of whom received more than 3 years of ZDV monotherapy. Baseline characteristics and all RT mutations were analyzed for impact on virologic suppression. Eight of 31 subjects (27%) achieved a virologic response of greater than 0.3 log reduction in plasma HIV RNA after 8 weeks of d4T. Responders were more likely to have lower median baseline viral loads (4.2 vs. 4.7; p =.01) and a trend toward fewer ZDV-associated mutations (median: 1 vs. 2; p =.09). No subject with greater than one ZDV mutation had a virologic response to d4T. Seven of the 8 responders had only a K70R mutation at baseline. We conclude that in patients with prior ZDV treatment, those with only one ZDV mutation, particularly at position 70, can still get reasonable virologic activity from d4T. Those with more mutations are not likely to have much benefit.

    View details for Web of Science ID 000170145500008

    View details for PubMedID 11468426

  • Phenotypic hypersusceptibility to non-nucleoside reverse transcriptase inhibitors in treatment-experienced HIV-infected patients: impact on virological response to efavirenz-based therapy AIDS Shulman, N., Zolopa, A. R., Passaro, D., Shafer, R. W., Huang, W., KATZENSTEIN, D., Israelski, D. M., Hellmann, N., Petropoulos, C., Whitcomb, J. 2001; 15 (9): 1125-1132

    Abstract

    Enhanced susceptibility to non-nucleoside reverse transcriptase inhibitors (NNRTI) was recently described in association with increased resistance to nucleoside analogs (nucleoside reverse transcriptase inhibitors; NRTI).To determine the prevalence of NNRTI hypersusceptibility, the genotypic correlates, and its impact on virologic response to efavirenz-based salvage therapy.Genotype and phenotype testing was performed retrospectively on baseline isolates from 30 patients who received salvage therapy containing efavirenz. NNRTI hypersusceptibility was defined as a 50% inhibitory concentration (IC(50)) of < 0.5 that of the wild-type control.Eight isolates had major NNRTI mutations. Among the 22 isolates with no major NNRTI mutations, 11 (50%) were hypersusceptible to efavirenz, 10 (45%) to delavirdine, and eight (36%) to nevirapine. Among eight isolates with NNRTI mutations, NNRTI resistance was present, but at lower than expected levels. The number of NRTI mutations was correlated inversely with the fold decrease in susceptibility to efavirenz (Spearman's rho, -0.57; P = 0.005), delavirdine (rho, -0.43; P = 0.04), and nevirapine (rho, -0.69; P < 0.001). Excluding subjects with NNRTI mutations, subjects with efavirenz hypersusceptibility at baseline had significantly better virologic suppression over 24 weeks than those without efavirenz hypersusceptibility (P < 0.001).NNRTI hypersusceptibility is common in heavily treated but NNRTI naive patients and is related directly to NRTI resistance mutations. Among patients receiving efavirenz-containing regimens, NNRTI hypersusceptibility was associated with an improved virologic outcome after 24 weeks of therapy. A reversal of phenotypic resistance was seen in patients with NNRTI mutations in the presence of multiple NRTI mutations, but no obvious virologic benefit of this phenomenon was seen in this study.

    View details for Web of Science ID 000169319400007

    View details for PubMedID 11416714

  • Virologic and CD4 cell response to zidovudine or zidovudine and lamivudine following didanosine treatment of human immunodeficiency virus infection AIDS RESEARCH AND HUMAN RETROVIRUSES Katzenstein, D. A., Hughes, M. D., Albrecht, M., Liou, S. H., Murphy, R., BALFOUR, H., Para, M., Hammer, S. 2001; 17 (3): 203-210

    Abstract

    To optimize nucleoside reverse transcriptase inhibitor (nRTI) antiretroviral therapy, 137 subjects who had been treated with didanosine monotherapy for more than 3 years in the AIDS Clinical Trials Group (ACTG) 175 study were randomized to zidovudine and didanosine (dual therapy) or zidovudine, didanosine, and lamivudine (triple therapy). Evaluation of early (8 week) change in HIV plasma RNA demonstrated that addition of lamivudine and zidovudine provided significantly greater virologic suppression compared to the addition of zidovudine alone (mean decrease of 1.27 vs. 0.74 log(10) copies/ml, n = 108, p = 0.007). Both dual and triple therapy provided significant long-term decreases (from study entry to mean at Weeks 40 and 48) in HIV plasma RNA: 0.62 and 0.86 log(10) copies/ml, respectively (n = 110). However, the difference between treatments was not significant (p = 0.16). At 48 weeks, 26% of subjects starting study treatment had <500 copies/ml of plasma HIV RNA. The CD4 count response was greater at 4 weeks for triple versus dual therapy: a mean increase of 51 vs. 12 CD4 cells/ml(3) (n = 126, p = 0.039). The difference at Weeks 40 and 48 was not significant (a 22 cell increase vs. a 1 cell decrease, n = 129, p = 0.41). Zidovudine and didanosine treatment, with or without lamivudine, was well tolerated and only 2 of 137 (1.5%) of study participants developed an AIDS-defining event over 48 weeks.

    View details for Web of Science ID 000166856500002

    View details for PubMedID 11177402

  • Vertical transmission of HIV in Africa: diagnostic testing and new interventions. HIV clinical trials KATZENSTEIN, D. 2000; 1 (3): 51-57

    View details for PubMedID 11590505

  • Randomized study of saquinavir with ritonavir or nelfinavir together with delavirdine, adefovir, or both in human immunodeficiency virus-infected adults with virologic failure on indinavir: AIDS Clinical Trials Group study 359 JOURNAL OF INFECTIOUS DISEASES Gulick, R. M., Hu, X. J., Fiscus, S. A., Fletcher, C. V., Haubrich, R., Cheng, H. L., Acosta, E., Lagakos, S. W., Swanstrom, R., Freimuth, W., Snyder, S., Mills, C., Fischl, M., Pettinelli, C., KATZENSTEIN, D. 2000; 182 (5): 1375-1384

    Abstract

    This study compared antiretroviral activity among 6 "salvage" therapy regimens. The study was a prospective, randomized, 2x3 factorial, multicenter study of the AIDS Clinical Trials Group. The study enrolled 277 human immunodeficiency virus (HIV)-infected patients naive to nonnucleoside analogues who had taken indinavir >6 months. The patients had 2000-200,000 HIV RNA copies/mL. Patients received saquinavir with ritonavir or nelfinavir together with delavirdine and/or adefovir and were followed for safety and antiretroviral response between baseline and week 16. At week 16, 30% (77/254) of patients had

    View details for Web of Science ID 000090106000012

    View details for PubMedID 11023461

  • HIV type 1 envelope subtype C sequences from recent seroconverters in Zimbabwe AIDS RESEARCH AND HUMAN RETROVIRUSES Batra, M., Tien, P. C., Shafer, R. W., Contag, C. H., Katzenstein, D. A. 2000; 16 (10): 973-979

    Abstract

    HIV-1 envelope sequence patterns have implications for virus cell tropism and for the development of an effective vaccine. To identify the sequence characteristics of recently transmitted HIV-1 isolates in southern Africa, we sequenced the V3-V5 envelope regions of 24 male seroconverters in Harare, Zimbabwe. Each of the sequences clustered with previously reported subtype C isolates and there was a mean 17% intersequence pairwise genetic distance between the Zimbabwean isolates. Three isolates were syncytium inducing (SI). One of the SI isolates had an unusual GIGK crown and a deletion at codon 23; one had the codon 23 deletion alone; and one had a high net positive charge in the V3 loop. The extensive genetic diversity within the envelope of subtype C HIV-1 isolates must be considered in vaccine development. Further analysis of subtype C SI isolates and site-directed mutagenesis experiments are required to determine the molecular basis of SI activity in global HIV-1 isolates.

    View details for Web of Science ID 000088006300006

    View details for PubMedID 10890359

  • Virologic and CD4(+) cell responses to new nucleoside regimens: switching to stavudine or adding lamivudine after prolonged zidovudine treatment of human immunodeficiency virus infection AIDS RESEARCH AND HUMAN RETROVIRUSES Katzenstein, D. A., Hughes, M., Albrecht, M., Hammer, S., Para, M., Murphy, R., Valdez, H., Haubrich, R., Liou, S. 2000; 16 (11): 1031-1037

    Abstract

    Clinical benefit of zidovudine alone in the treatment of HIV infection wanes after several years, with decreasing CD4+ cell numbers and increasing HIV RNA in plasma. To develop treatment strategies following prolonged zidovudine treatment, 92 subjects from the AIDS Clinical Trials Group (ACTG) 175 study after a median of 3.6 years of zidovudine monotherapy were randomized to treatment with stavudine or zidovudine and lamivudine. Evaluation of long-term changes, the average of 40- and 48-week HIV plasma RNA, demonstrated that lamivudine and zidovudine provided significantly greater virologic suppression compared with stavudine (mean decrease 0.70 versus 0.18 1og10 copies/ml,p = 0.003). Twenty-nine percent of zidovudine plus lamivudine recipients had HIV RNA levels below 500 copies per milliliter at 48 weeks as compared with 4% of stavudine recipients (p = 0.02). Both regimens significantly increased CD4+ cell numbers, the means of weeks 40 and 48 rose to 49 and 36 CD4+ cells per cubic millimeter among zidovudine plus lamivudine and stavudine recipients, respectively. Treatments were well tolerated and only 3 of 92 subjects died or developed AIDS within 48 weeks. In zidovudine-experienced subjects, addition of lamivudine resulted in significantly decreased plasma HIV RNA levels at 48 weeks compared with treatment with stavudine alone.

    View details for Web of Science ID 000088122900003

    View details for PubMedID 10933617

  • Efavirenz- and adefovir dipivoxil-based salvage therapy in highly treatment-experienced patients: Clinical and genotypic predictors of virologic response JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Shulman, N. S., Zolopa, A. R., Passaro, D. J., Murlidharan, U., Israelski, D. M., Brosgart, C. L., Miller, M. D., Van Doren, S., Shafer, R. W., Katzenstein, D. A. 2000; 23 (3): 221-226

    Abstract

    To determine the impact of prior nonnucleoside reverse transcriptase inhibitor (NNRTI) therapy, genotypic resistance, and other variables on response to efavirenz (EFV)- and adefovir dipivoxil (ADV)-based salvage therapy.Retrospective clinical cohort study.One university and one community-based HIV clinic.All 33 patients who were coenrolled in both the EFV and ADV expanded access programs.Patients received EFV 600 mg/day and ADV 120 mg/day in addition to other antiretroviral agents.HIV viral load (<500 copies/ml) at 12 and 24 weeks.10 of 33 (30%) patients at 12 weeks and 8 of 33 (24%) patients at 24 weeks had viral loads <500 copies/ml. Prior NNRTI use and a history of any NNRTI-associated mutations predicted failure. Patients with Y181C or G190A single mutations had an initial greater magnitude of viral load suppression than those with K103N, but this advantage was short lived. No one with any NNRTI mutations responded with a viral load <500 copies/ml at 12 or 24 weeks.EFV/ADV-based salvage yielded viral load suppression at 24 weeks in 42% (8 of 19) of patients who were highly NRTI and protease inhibitor experienced but NNRTI naive. NNRTI-experienced study subjects had a poor response regardless of the specific NNRTI resistance mutation they harbored.

    View details for Web of Science ID 000086883600002

    View details for PubMedID 10839657

  • HIV-1 genotypic resistance patterns predict response to saquinavir-ritonavir therapy in patients in whom previous protease inhibitor therapy had failed ANNALS OF INTERNAL MEDICINE Zolopa, A. R., Shafer, R. W., Warford, A., Montoya, J. G., Hsu, P., KATZENSTEIN, D., Merigan, T. C., Efron, B. 1999; 131 (11): 813-?

    Abstract

    Tests for resistance to HIV drugs are available for clinical use; however, their predictive value has not been fully assessed.To determine HIV-1 genotypic predictors of a virologic response to saquinavir-ritonavir therapy in patients in whom at least one previous protease inhibitor-containing regimen had failed and to compare the predictive value of baseline genotype with that of standard clinical evaluation.Retrospective clinical cohort study.University-based HIV clinic.54 HIV-1-infected adults treated with saquinavir-ritonavir who had experienced virologic failure while receiving a protease inhibitor-containing regimen for at least 3 months.HIV-1 reverse transcriptase and protease gene sequences, CD4 cell counts, clinical characteristics, detailed antiretroviral treatment history, and plasma HIV-1 RNA levels at baseline and at three follow-up time points (median, 4, 12, and 26 weeks). Virologic failure was defined as a plasma HIV RNA level greater than 1000 copies/mL.In 22 patients (41%), a plasma HIV-1 RNA level less than 500 copies/mL was achieved by week 12; in 15 patients (28%), this response was maintained through week 26. Clinical characteristics predicting a poorer response included a diagnosis of AIDS, lower CD4 cell count, and higher plasma HIV RNA level (P<0.03). Number of previous nucleoside reverse transcriptase inhibitors, previous protease inhibitor therapy, and duration of previous protease inhibitor therapy were predictors of poorer response (P<0.01). Multivariate regression models revealed that protease mutations present at the initiation of saquinavir-ritonavir therapy were the strongest predictors of virologic response. A model of clinical features explained up to 45% of the variation in virologic outcomes by week 12, whereas the explained variance was 71% when genotypic predictors were included.In patients in whom protease inhibitor-containing antiretroviral therapy fails, HIV-1 genotype is predictive of virologic response to subsequent therapy. This predictive capacity adds to that of standard clinical evaluation.

    View details for PubMedID 10610625

  • Delayed-type hypersensitivity to recombinant HIV envelope glycoprotein (rgp160) after immunization with homologous antigen JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Katzenstein, D. A., Kundu, S., Spritzler, J., SMOLLER, B. R., Haszlett, P., Valentine, F., Merigan, T. C. 1999; 22 (4): 341-347

    Abstract

    Delayed-type hypersensitivity (DTH) responses to intradermal recombinant HIV envelope glycoprotein (rgp160) may assess cell-mediated immune responses to HIV envelope. In three studies, DTH and lymphocyte proliferation responses to rgp160 were obtained in a total of 106 HIV-seropositive subjects with CD4+ counts >400 cells/mm3. Several subjects participated in more than one study. Before immunization, DTH responses were seen in 5 of 56 (9%) of HIV-infected study subjects. After immunization with an alum-adjuvanted experimental rgp160 vaccine, DTH responses were seen in 46 of 52 (89%). Using in vitro lymphocyte proliferation activity (LPA) to rgp160 as an indication of cellular immune response, skin testing has a sensitivity of 0.75 (95% confidence Interval [CI], 0.59-0.88) and a specificity of 0.84 (95% CI, 0.72-0.92). Biopsy samples of skin that had tested positive confirmed the presence of a DTH reaction with a predominance of CD4+ T cells in the perivascular, inflammatory infiltrate. Skin testing before and after immunization with candidate AIDS vaccines could provide a simple method in the field to assess new cell mediated immune responses.

    View details for Web of Science ID 000085336400004

    View details for PubMedID 10634195

  • The contribution of assay variation and biological variation to the total variability of plasma HIV-1 RNA measurements AIDS Brambilla, D., REICHELDERFER, P. S., Bremer, J. W., Shapiro, D. E., Hershow, R. C., Katzenstein, D. A., Hammer, S. M., Jackson, B., Collier, A. C., Sperling, R. S., Fowler, M. G., COOMBS, R. W. 1999; 13 (16): 2269-2279

    Abstract

    To assess the specific contributions of assay variation and biological variation to the total variation of plasma HIV-1 RNA measured by the Roche Monitor assay and the extent to which batch assays reduced both assay variability and total variability compared with real-time determinations.A retrospective analysis of data obtained from three trials conducted by the Adult and Pediatric AIDS Clinical Trials Groups (ATCG), the Women and Infants Transmission Study (WITS) and the NIAID-sponsored Virology Quality Assurance Program.Within-subject variation was assessed from stored, serially collected plasma samples from 663 subjects enrolled in the ACTG and WITS studies. Interassay and intra-assay variation were estimated from two of the clinical trials and 22 laboratories that participated in a quality assurance program and were used to estimate the effect of real-time testing on total variation.The total variation (standard deviation) from a random effects model was 0.26 log10 RNA copies/ml. The estimated interassay variation was 0.08 log10 and intra-assay variation was 0.12 log10 RNA copies/ml. Biological variation accounted for 56-80% of total variation. The effect of real-time testing compared with batch testing was minimal.Our estimates of total within-subject HIV-1 RNA variation support the current recommendation to obtain at least two specimens, preferably obtained less than 2 weeks apart, for viral RNA measurement before starting therapy. The major contribution of biological variation to the total variation supports the use of real-time HIV-1 RNA assays, provided that consistent specimen collection procedures are followed and acceptable assay proficiency is maintained.

    View details for Web of Science ID 000083510700009

    View details for PubMedID 10563712

  • Serum level of maternal human immunodeficiency virus (HIV) RNA, infant mortality, and vertical transmission of HIV in Zimbabwe Conference on Global Strategies for the Prevention of HIV Transmission from Mothers to Infants Katzenstein, D. A., Mbizvo, M., Zijenah, L., Gittens, T., Munjoma, M., Hill, D., Madzime, S., Maldonado, Y. UNIV CHICAGO PRESS. 1999: 1382?87

    Abstract

    Maternal human immunodeficiency virus (HIV) RNA load, vertical transmission of subtype C HIV, and infant mortality were examined in 251 HIV-seropositive women and their infants in Zimbabwe. Demographic characteristics, health and medical histories, serum HIV RNA loads, and CD4+ lymphocyte counts for mothers were examined by logistic regression analysis to determine significant risk factors and their odds ratios for transmission and infant mortality. Tenfold (1 log10) incremental increases in maternal HIV RNA were associated with a 1.9-fold increase (95% confidence interval [CI], 1.2-2.9) in transmission and a 2.1-fold increase (95% CI, 1.3-3.5) in infant mortality (P<.01). Maternal CD4 cell counts and demographic and medical characteristics were not significant predictors of transmission. However, maternal CD4 cell counts below the median (400/mm3) were significantly associated with infant mortality (P=. 035, Fisher's exact test). The maternal level of serum HIV is an important determinant of vertical transmission and infant mortality in subtype C infection in Zimbabwe.

    View details for Web of Science ID 000080561100010

    View details for PubMedID 10228058

  • Primary subtype C HIV-1 infection in Harare, Zimbabwe JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Tien, P. C., Chiu, T., Latif, A., Ray, S., Batra, M., Contag, C. H., Zejena, L., Mbizvo, M., Delwart, E. L., Mullins, J. I., Katzenstein, D. A. 1999; 20 (2): 147-153

    Abstract

    Heterosexual transmission of HIV-1 is widespread in Southern Africa. Heteroduplex mobility assays (HMA) and phylogenetic analyses of V3-V5 envelope (env) gene sequences demonstrate that subtype C predominates in Zimbabwe. To elucidate factors contributing to the epidemic in Zimbabwe, clinical and virologic characteristics of recently acquired subtype C HIV-1 infection among 21 men and 1 woman were determined. In 12 of 19 men providing clinical histories, a sexually transmitted infection preceded serologic evidence of HIV-1, and 14 of 19 men complained of rash or fever before seroconversion. Quantitative p24 antigen levels, reverse transcriptase activity, and HIV RNA levels of 22 viral isolates correlated with in vitro infectivity in peripheral blood mononuclear cells (p < .05). Biologic phenotype assessed in MT-2 cells demonstrated that 3 of 22 isolates (14%) were syncytia inducing (SI) and the remaining 19 nonsyncytium inducing (NSI). Early growth of virus in culture was associated with increased plasma HIV RNA levels, decreased CD4 cell levels, and SI virus. Recent subtype C HIV-1 infection through heterosexual transmission in Zimbabwe demonstrated clinical and virologic features consistent with reports of seroconversion to subtype B viruses.

    View details for Web of Science ID 000078390800006

    View details for PubMedID 10048901

  • Detection of Kaposi's sarcoma-associated herpesvirus in peripheral blood cells in human immunodeficiency virus infection: Association with Kaposi's sarcoma, CD4 cell count, and HIV RNA levels AIDS RESEARCH AND HUMAN RETROVIRUSES Min, J., Katzenstein, D. A. 1999; 15 (1): 51-55

    Abstract

    Kaposi's sarcoma-associated herpesvirus (KSHV) DNA, consistently found in Kaposi's sarcoma (KS) tissues, was sought in peripheral blood mononuclear cells (PBMCs) of HIV-infected individuals. To determine quantitative relationships between the presence of KSHV DNA in PBMCs, CD4 cell counts, plasma HIV RNA levels, and the development of KS, we designed a cross-sectional study of prospectively collected PBMC samples from ongoing cohort studies. PBMCs were collected from 142 HIV-seropositive individuals in California, 7 of whom had a clinical diagnosis of KS. KSHV sequences were detected in extracted PBMC DNA by nested polymerase chain amplification using two nonoverlapping primer sets. KSHV DNA was detected in PBMCs of 5 of 7 (71%) subjects with KS and in 18 of 135 (13%) HIV-infected subjects without KS. Among HIV-seropositive individuals without KS, detection of KSHV was more common in men than women (19 versus 4%, p = 0.01) and was associated with lower mean CD4 percent (14.8 versus 20.7% CD4 cells, p = 0.03), lower mean CD4 cell count (244 versus 334 CD4 cells/microl, p = 0.05), and higher geometric mean plasma HIV RNA (4.83 versus 4.03 1og10 copies/ml, p = 0.0002). Semiquantitative analysis found 5 to 15,625 copies of KSHV per microgram of PBMC DNA with increased plasma HIV RNA levels and a trend toward increased subsequent development of KS in subjects with higher KSHV loads. The association of the presence of KSHV DNA in PBMCs with lower CD4 cell counts and higher plasma HIV RNA provides evidence of a relationship between immunosuppression, HIV replication, and KSHV expression.

    View details for Web of Science ID 000078069400007

    View details for PubMedID 10024052

  • Sequence and drug susceptibility of subtype C protease from human immunodeficiency virus type 1 seroconverters in Zimbabwe AIDS RESEARCH AND HUMAN RETROVIRUSES Shafer, R. W., Chuang, T. K., Hsu, P., White, C. B., Katzenstein, D. A. 1999; 15 (1): 65-69

    View details for Web of Science ID 000078069400009

    View details for PubMedID 10024054

  • Neuromuscular function in HIV infection: analysis of a placebo-controlled combination antiretroviral trial AIDS Simpson, D. M., Katzenstein, D. A., Hughes, M. D., Hammer, S. M., Williamson, D. L., Jiang, Q., Pi, J. T. 1998; 12 (18): 2425-2432

    Abstract

    To determine the frequency of peripheral neuropathy and myopathy in HIV-infected subjects enrolled in a combination antiretroviral treatment trial.AIDS Clinical Trial Group (ACTG) protocol 175 was a multicenter, double-blind, placebo-controlled, clinical trial. A total of 2467 subjects were randomized to one of four single or combination regimens, containing zidovudine (ZDV), didanosine (ddl), zalcitabine (ddC), and their respective placebos. Site investigators reported peripheral neuropathy, and the diagnosis of distal symmetrical neuropathy (DSP) was established by the study authors. Myalgia, muscle weakness and creatine phosphokinase (CPK) were prospectively assessed in a subset of the antiretroviral-naive cohort (n = 1067).Of 222 site diagnoses of neuropathy, 109 (49%) were DSP. There was a significant difference between treatment arms for rate of DSP and time to first grade 2 or higher DSP (ZDV-ddC, 6%; ZDV, 4%; ZDV-ddl, 4%; ddl, 3%; P = 0.029). Age and Karnofsky score were significant predictors of DSP. Fifty-six (54%) out of 104 patients with DSP remained on study medication at full (n = 29) or reduced (n = 27) dose within 6 months of developing neuropathy. There was no significant difference between treatment arms in the rate of myalgia or muscle weakness. The median CPK of subjects on ZDV-ddC was significantly higher than other study treatments, although CPK levels did not correlate with symptoms of myopathy. Only six subjects were diagnosed with myopathy during the study (one ZDV-ddl, one ZDV-ddC, and four ddl).DSP and myopathy may occur with current dosing regimens of combination antiretroviral therapy, and should be diagnosed using stringent criteria. ZDV-ddC was associated with the highest rate of DSP, although features of myopathy were not significantly different between treatment regimens.

    View details for Web of Science ID 000077550000011

    View details for PubMedID 9875580

  • The extent of non-adherence in a large AIDS clinical trial using plasma dideoxynucleoside concentrations as a marker 95th Annual Meeting of the American-Society-of-Clinical-Pharmacology Kastrissios, H., Suarez, J. R., Hammer, S., KATZENSTEIN, D., Blaschke, T. F. LIPPINCOTT WILLIAMS & WILKINS. 1998: 2305?11

    Abstract

    To assess adherence to study medications in an AIDS clinical trial, to evaluate whether study participants adhered to only one component of a multidrug regimen ('differential adherence'), and to determine whether there was evidence of non-uniform adherence to study medications among treatment groups.This was a substudy of AIDS Clinical Trials Group protocol 175, a large, double-blind, randomized study of monotherapy versus combination dideoxynucleoside therapy. Participants were required to adhere to a complex regimen of zidovudine, zalcitabine and didanosine, or their matching placebos.Between October 1992 and January 1994, study sites were selected at random, and a 1-week period was designated during which study participants attending routine clinic visits provided a blood sample and dosing history. Participants were not informed of the purpose of the substudy.Adherence was assessed using plasma drug concentrations and defined by the presence of detectable drug in a plasma sample obtained within a specified analysis window.Of 722 plasma samples analyzed, approximately 75% contained detectable concentrations of the assigned drugs and 5-14.5% contained no detectable drugs. Approximately 7 and 13% of samples from participants assigned to monotherapy arms contained non-prescribed dideoxynucleosides, and 14 and 19% assigned to combination therapies contained only one drug.Various non-adherence behaviors were observed, including patterns of underdosing and taking non-prescribed drugs. Non-adherence was moderate but uniform amongst the treatment groups and may have contributed to a marginal reduction in the power of the primary intent-to-treat analysis to detect differences in efficacy amongst the assigned treatments.

    View details for Web of Science ID 000077173000012

    View details for PubMedID 9863873

  • Characterizing patterns of drug-taking behavior with a multiple drug regimen in an AIDS clinical trial 96th Annual Meeting of the American-Society-of-Clinical-Pharmacology Kastrissios, H., Suarez, J. R., KATZENSTEIN, D., GIRARD, P., Sheiner, L. B., Blaschke, T. F. LIPPINCOTT WILLIAMS & WILKINS. 1998: 2295?2303

    Abstract

    To characterize drug-taking behavior using continuous electronic monitoring in an AIDS clinical trial.This was a substudy of AIDS Clinical Trials Group (ACTG) protocol 175, a phase II/III study of dideoxynucleoside monotherapy versus combination therapy in asymptomatic HIV-positive subjects. Participants were required to comply with regimens containing zidovudine, zalcitabine and didanosine, or matching placebos; the total daily pill count was 16.For participants at two ACTG 175 sites, electronic devices were used to monitor drug-taking behavior of all study medications over a period of approximately 90 days.Four indices of drug-taking behavior were calculated and their distributions and relationship to the prescribed regimen were examined.Data from 41 subjects were analyzed. Of the prescribed doses of zidovudine, zalcitabine and didanosine, 88, 84 and 82%, respectively, were taken. Of these, 55, 66 and 79%, respectively, were taken at the prescribed dosing frequency. The median percentage of days on which participants failed to take any of the doses was 2-5%. There was a trend towards lower adherence in the combination therapy arms compared with those assigned to receive monotherapy. In this analysis, older patients demonstrated better adherence, although patient characteristics, in general, were poorly predictive of adherence.Drug-taking behavior for all three active study medications differed from that prescribed. One result of this erratic adherence was that study participants sustained little antiretroviral effect during more than 25% of the monitoring period.

    View details for Web of Science ID 000077173000011

    View details for PubMedID 9863872

  • A 6-basepair insert in the reverse transcriptase gene of human immunodeficiency virus type 1 confers resistance to multiple nucleoside inhibitors 2nd International Workshop on HIV Drug Resistance and Treatment Strategies Winters, M. A., Coolley, K. L., Girard, Y. A., Levee, D. J., Hamdan, H., Shafer, R. W., Katzenstein, D. A., Merigan, T. C. AMER SOC CLINICAL INVESTIGATION INC. 1998: 1769?75

    Abstract

    While many point mutations in the HIV-1 reverse transcriptase (RT) confer resistance to antiretroviral drugs, inserts or deletions in this gene have not been previously characterized. In this report, 14 RT inhibitor-treated patients were found to have HIV-1 strains possessing a 6-basepair insert between codons 69 and 70 of the RT gene. Known drug resistance mutations were also observed in these strains, with T215Y appearing in all strains. Genotypic analysis indicated that the inserts had substantial nucleotide variability that resulted in relatively restricted sets of amino acid sequences. Linkage of patients' treatment histories with longitudinal sequencing data showed that insert strains appeared during drug regimens containing ddI or ddC, with prior or concurrent AZT treatment. Drug susceptibility tests of recombinant patient isolates showed reduced susceptibility to nearly all nucleoside RT inhibitors. Site- directed mutagenesis studies confirmed the role of the inserts alone in conferring reduced susceptibility to most RT inhibitors. The addition of AZT-associated drug resistance mutations further increased the range and magnitude of resistance. These results establish that inserts, like point mutations, are selected in vivo during antiretroviral therapy and provide resistance to multiple nucleoside analogs.

    View details for Web of Science ID 000077205900001

    View details for PubMedID 9819361

    View details for PubMedCentralID PMC509125

  • Mortality in the first 2 years among infants born to human immunodeficiency virus-infected women in Harare, Zimbabwe 4th Conference on Retroviruses and Opportunistic Infections Zijenah, L., Mbizvo, M. T., Kasule, J., Nathoo, K., Munjoma, M., Mahomed, K., Maldonado, Y., Madzime, S., Katzenstein, D. OXFORD UNIV PRESS INC. 1998: 109?13

    Abstract

    Transmission of human immunodeficiency virus (HIV) and mortality was studied among infants of infected women in Zimbabwe. Of 367 infants born to HIV-infected women, 72 (19.6%) died compared with 20 (5.4%) of 372 infants of uninfected women (P < .01). Infection by HIV DNA polymerase chain reaction among infants who survived >7 days and died within 2 years could be assessed in 87% (58/67) of infants of infected women and 83% (5/6) of infants of uninfected women; transmission occurred in 40 of 58 infants. Among 27 infected infants tested at birth, 19 (70%), 5 (19%), and 3 (11%) were apparently infected via in utero, intrapartum or early postpartum, and late postpartum transmission, respectively. The majority of HIV-infected infants who died in the first 2 years of life were likely to have acquired in utero infection.

    View details for Web of Science ID 000074357900014

    View details for PubMedID 9652429

  • Geographic and demographic differences in the frequency of human cytomegalovirus gB genotypes 1-4 in immunocompromised patients AIDS RESEARCH AND HUMAN RETROVIRUSES Zipeto, D., Hong, C., Gerna, G., Zavattoni, M., KATZENSTEIN, D., Merigan, T. C., Rasmussen, L. 1998; 14 (6): 533-536

    Abstract

    To test the hypothesis that human cytomegalovirus (CMV) gB genotype may differ with geographic origin or patient demographics, CMV DNA was amplified for gB typing from immunocompromised patients in Italy and Africa and compared with previously reported frequencies in California. Increased gB2 frequency occurred in Italian homosexual AIDS patients, as compared with both Italian heterosexual injection drug users with AIDS and heterosexual Zimbabwe AIDS patients. Occurrence of gB3 in Italy was higher in injection drug users than in homosexual AIDS patients. The incidence of gB4 was higher overall in the Italian as compared with the California patients. Therefore geographic and demographic differences in patients affect gB distribution and should be considered before associations of gB genotypes and virulence are made.

    View details for Web of Science ID 000072993500009

    View details for PubMedID 9566556

  • Human immunodeficiency virus type 1 RNA shedding in the female genital tract JOURNAL OF INFECTIOUS DISEASES Goulston, C., McFarland, W., KATZENSTEIN, D. 1998; 177 (4): 1100-1103

    Abstract

    Cervical and plasma samples obtained twice, at 2-week intervals, from 49 human immunodeficiency virus type 1 (HIV-1)-positive women were assayed for HIV-1 RNA. More than 100 copies of HIV-1 RNA were detected in cervical swab supernatants (CSS) from 24 (49%) of 49 women. HIV-1 RNA in CSS was detected in younger women with higher levels of plasma HIV-1 RNA (median, 31,984 vs. 2880 copies/mL; P = .0004), lower CD4 cell counts (median, 190 vs. 390 per mm3; P = .012), and lower CD4 cell percents (median, 16% vs. 25%; P = .03). In multiple logistic regression analysis, only plasma HIV-1 RNA was significantly associated with CSS HIV-1 RNA, with an odds ratio of 4.79/log10 increase in plasma HIV-1 RNA (95% confidence interval, 1.4-16; P = .01). Detection of HIV-1 RNA in cervical secretions is primarily associated with increased plasma HIV-1 RNA.

    View details for Web of Science ID 000072719400040

    View details for PubMedID 9534992

  • HIV-1 reverse transcriptase codon 215 mutation in plasma RNA: Immunologic and virologic responses to zidovudine JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Rey, D., Hughes, M., Pi, J. T., Winters, M., Merigan, T. C., Katzenstein, D. A. 1998; 17 (3): 203-208

    Abstract

    Treatment of HIV infection with zidovudine (ZDV) may select for changes in the genetic sequence of the viral reverse transcriptase (RT) that imparts drug resistance. The presence of a 2-bp mutation at codon 215 of RT (from threonine to phenylalanine or tyrosine) was assessed in plasma viral RNA in 85 subjects treated with ZDV in the AIDS Clinical Trials Group (ACTG) 175 virology substudy. Median CD4 cell numbers, HIV plasma RNA levels, and infectious titers of virus were significantly different over 56 weeks of treatment among 58 subjects with the wild-type threonine at codon 215 virus at study entry compared with the 27 subjects with mutations to phenylalanine or tyrosine (MUT) virus. Thirty percent (13 of 44 subjects) with wild-type virus at study entry developed a new codon 215 mutation. Genotypic resistance at codon 215 in plasma HIV RNA is associated with the subsequent immunologic and virologic failure of ZDV monotherapy in subjects with 200 to 500 CD4 cells/mm3.

    View details for Web of Science ID 000072312900003

    View details for PubMedID 9495218

  • Polymerase chain reaction detection of Haemophilus ducreyi DNA SEXUALLY TRANSMITTED INFECTIONS Roesel, D. J., Gwanzura, L., Mason, P. R., Joffe, M., Katzenstein, D. A. 1998; 74 (1): 63-65

    Abstract

    To develop a polymerase chain reaction (PCR) method to detect Haemophilus ducreyi DNA in cultured isolates and clinical material.Primers specific to the H ducreyi 16s rRNA gene were synthesised. PCR conditions were optimised and products were verified by restriction endonuclease digestion and agarose gel electrophoresis.The method was able to detect all 28 H ducreyi strains tested; specificity was demonstrated using lysates of 12 related organisms. Applied to clinical samples from genital ulcer swabs obtained in Harare, Zimbabwe, H ducreyi DNA was detected in repeated assays in 35 clinical samples.PCR amplification using primers from the 16s rRNA gene may be a useful alternative to culture for the detection of H ducreyi and the diagnosis of chancroid.

    View details for Web of Science ID 000073154900016

    View details for PubMedID 9634308

  • Use of changes in plasma levels of human immunodeficiency virus type 1 RNA to assess the clinical benefit of antiretroviral therapy JOURNAL OF INFECTIOUS DISEASES Marschner, I. C., Collier, A. C., COOMBS, R. W., D'Aquila, R. T., DeGruttola, V., Fischl, M. A., Hammer, S. M., Hughes, M. D., JOHNSON, V. A., Katzenstein, D. A., Richman, D. D., Smeaton, L. M., Spector, S. A., Saag, M. S. 1998; 177 (1): 40-47

    Abstract

    Data from 1330 human immunodeficiency virus type 1 (HIV-1)-infected patients enrolled in seven antiretroviral treatment trials were analyzed to characterize the clinical benefit of treatment-mediated reductions in plasma HIV-1 RNA levels. The risk of a new AIDS-defining event or death was reduced proportionally to the magnitude of the reduction of the HIV-1 RNA level during the first 6 months of therapy. Pretherapy HIV-1 RNA levels were prognostic independently of on-therapy levels. In addition, the reduction in risk associated with any given reduction of the level of HIV-1 RNA did not vary by pretherapy level. Having either a reduction in HIV-1 RNA level or an increase in CD4+ lymphocyte count, or both, was associated with a delay in clinical disease progression. This indicates that patient prognosis should be assessed using both HIV-1 RNA and CD4+ lymphocyte responses to therapy.

    View details for Web of Science ID 000071080700008

    View details for PubMedID 9419168

  • Combination therapies for HIV infection and genomic drug resistance LANCET KATZENSTEIN, D. 1997; 350 (9083): 970-971

    View details for Web of Science ID A1997XZ71000002

    View details for PubMedID 9329506

  • Effect of therapeutic immunization with recombinant gp160 HIV-1 vaccine on HIV-1 proviral DNA and plasma RNA: Relationship to cellular immune responses JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Kundu, S. K., KATZENSTEIN, D., Valentine, F. T., Spino, C., Efron, B., Merigan, T. C. 1997; 15 (4): 269-274

    Abstract

    Therapeutic vaccination has been proposed as a strategy to augment immune mechanisms to control viral replication and slow clinical progression of HIV infection to disease. Following recombinant gp160 (r-gp160) immunization in three clinical trials, plasma HIV-1 RNA and cellular proviral DNA were assessed by quantitative polymerase chain reaction (PCR) in 76 HIV-seropositive subjects with CD4+ T cell counts > or = 300/mm3. Immunization increased HIV-specific cellular immune responses (e.g., cytotoxic T lymphocyte [CTL] activities, lymphocyte proliferative responses); however, there were no significant effects of immunization or cellular immune responses on measures of plasma RNA or cellular DNA viral load.

    View details for Web of Science ID A1997YA52500004

    View details for PubMedID 9292585

  • Measuring quality of life in early HIV disease: the modular approach QUALITY OF LIFE RESEARCH Lenderking, W. R., Testa, M. A., KATZENSTEIN, D., Hammer, S. 1997; 6 (6): 515-530

    Abstract

    to examine the reliability and validity of the General Health Self-assessment, a modular questionnaire for self-assessment of quality of life (QoL) in human immunodeficiency virus (HIV) clinical trials and to describe the baseline QoL of participants in a large HIV clinical trial.the domains assessed include health perceptions, physical, psychological and role/social functioning, health care utilization and symptom distress.1,694 subjects with early HIV infection enrolled in the AIDS Clinical Trials Group Protocol 175 completed the scale at baseline.the domains demonstrated reliability, construct and discriminant validity. A worse QoL was associated with recent hospitalization and symptomatic status. Prior antiretroviral therapy was associated with higher health perceptions and well-being. The presence of symptom distress was related to lower QoL on the other scales. There was no relationship between QoL scales and the baseline CD4 count. Women showed a lower QoL than men on all scales, while ethnicity was related to differences in health perceptions and physical and psychological functioning.the General Health Self-assessment shows excellent potential as a measure of QoL for HIV-infected patients in clinical trials. Further research is necessary to determine the responsiveness of the scale to clinical and immunological changes in HIV-infected individuals.

    View details for Web of Science ID A1997XX98000007

    View details for PubMedID 9330552

  • Sequence and drug susceptibility of subtype C reverse transcriptase from human immunodeficiency virus type 1 seroconverters in Zimbabwe JOURNAL OF VIROLOGY Shafer, R. W., Eisen, J. A., Merigan, T. C., Katzenstein, D. A. 1997; 71 (7): 5441-5448

    Abstract

    Naturally occurring human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) variability has implications for the success of antiretroviral therapy. We determined the sequence of the polymerase-coding region of RT from virus isolates from 12 Zimbabwean individuals recently infected with HIV-1. The 12 RT sequences differed from the consensus B RT sequence at 10.5% of nucleotides and 5.8% of amino acids. Susceptibility testing of five isolates to zidovudine, didanosine, lamivudine, and nevirapine demonstrated susceptibilities similar to those of wild-type subtype B isolates. Phylogenetic analysis of 40 HIV-1 RT sequences, including the 12 Zimbabwean subtype C sequences, 11 subtype B sequences, and the 17 remaining published non-subtype B sequences showed sufficient intrasubtype RT sequence variation to differentiate subtype A, B, C, and D isolates. Five recently reported subtype C RT sequences from India grouped with the Zimbabwean subtype C sequences but had significantly less intraisolate sequence variation. Both intra- and intersubtype RT comparisons were notable for extraordinarily high ratios of synonymous to nonsynonymous differences. Although substitutions in the HIV-1 RT gene are limited by functional constraints, variation between RT sequences demonstrates phylogenetic relationships that parallel env and gag gene variation.

    View details for Web of Science ID A1997XD82900068

    View details for PubMedID 9188616

    View details for PubMedCentralID PMC191784

  • Antiretroviral therapy for human immunodeficiency virus infection in 1997 WESTERN JOURNAL OF MEDICINE Katzenstein, D. A. 1997; 166 (5): 319-325

    Abstract

    It has become clear that the acquired immunodeficiency syndrome follows continuous replication of the human immunodeficiency virus (HIV) and a decrease in immune capability, most obviously a decline in the number of CD4 lymphocytes. An understanding of key elements in the infectious life cycle of HIV has led to the development of potent antiretroviral drugs selectively targeting unique reverse transcriptase and protease enzymes of the virus. Completed clinical trials have shown that antiretroviral therapy for HIV infection, begun early, reduces viral replication and reverses the decline in CD4 lymphocyte numbers. Recent studies of combination therapies have shown that decreases in plasma HIV viremia to low levels and sustained increases in CD4 cell numbers are associated with longer survival. Potent combination regimens including protease inhibitors and non-nucleoside reverse transcriptase inhibitors suppress detectable viral replication and have demonstrated clinical benefits in patients with advanced disease. Progress in antiretroviral therapy and methods to monitor responses to treatment are providing new hope in the treatment of HIV infection.

    View details for Web of Science ID A1997XG11900003

    View details for PubMedID 9217434

  • HIV therapeutics: confronting adherence. journal of the Association of Nurses in AIDS Care : JANAC Katzenstein, D. A., Lyons, C., Molaghan, J. P., UNGVARSKI, P., Wolfe, G. S., Williams, A. 1997; 8: 46-58

    View details for PubMedID 9356962

  • Adherence as a particular issue with protease inhibitors. journal of the Association of Nurses in AIDS Care : JANAC Katzenstein, D. A. 1997; 8: 10-17

    Abstract

    Suboptimal therapeutic doses of HIV protease inhibitors lead to the emergence of drug resistance and reduced drug efficacy. It is imperative, then, that patients and clinicians alike are fully educated about the importance of patients taking all the pills in these new, admittedly complex, antiretroviral regimens. With protease inhibitors especially, missing doses and/or taking drug holidays or partial doses will mean the rapid emergence of HIV isolates that are resistant to these drugs.

    View details for PubMedID 9356957

  • The relation of virologic and immunologic markers to clinical outcomes after nucleoside therapy in HIV-infected adults with 200 to 500 CD4 cells per cubic millimeter NEW ENGLAND JOURNAL OF MEDICINE Katzenstein, D. A., Hammer, S. M., Hughes, M. D., Gundacker, H., Jackson, J. B., Fiscus, S., Rasheed, S., Elbeik, T., REICHMAN, R., Japour, A., Merigan, T. C., Hirsch, M. S. 1996; 335 (15): 1091-1098

    Abstract

    We studied measures of human immunodeficiency virus (HIV) replication, the viral phenotype, and immune function (CD4 cell counts) and the relation of changes in these indicators to clinical outcomes in a subgroup of patients in a controlled trial of early antiretroviral treatment for HIV, the AIDS Clinical Trials Group Study 175.The 391 subjects, each of whom entered the study with a single screening CD4 cell count of 200 to 500 per cubic millimeter, were randomly assigned to receive zidovudine alone, didanosine alone, zidovudine plus didanosine, or zidovudine plus zalcitabine. Plasma concentrations of HIV RNA were assessed in 366 subjects, and viral isolates from 332 subjects were assayed for the presence of the syncytium-inducing phenotype.After eight weeks, the mean (+/-SE) decrease from base line in the concentration of HIV RNA, expressed as the change in the base 10 log of the number of copies per milliliter, was 0.26+/-0.06 for patients treated with zidovudine alone, 0.65+/-0.07 for didanosine alone, 0.93+/-0.10 for zidovudine plus didanosine, and 0.89+/-0.06 for zidovudine plus zalcitabine (P<0.001 for each of the pairwise comparisons with zidovudine alone). Multivariate proportional-hazards models showed that higher base-line concentrations of plasma HIV RNA, less suppression of plasma HIV RNA by treatment, and the presence of the syncytium-inducing phenotype were significantly associated with an increased risk of progression to the acquired immunodeficiency syndrome and death. After adjustment for these measures of viral replication and for the viral phenotype, CD4 cell counts were not significant predictors of clinical outcome.Both the risk of the progression of HIV disease and the efficacy of antiretroviral therapy are strongly associated with the plasma level of HIV RNA and with the viral phenotype. The changes in the plasma concentration of HIV RNA predict the changes in CD4 cell counts and survival after treatment with reverse-transcriptase inhibitors.

    View details for Web of Science ID A1996VN39900002

    View details for PubMedID 8813039

  • A trial comparing nucleoside monotherapy with combination therapy in HIV-infected adults with CD4 cell counts from 200 to 500 per cubic millimeter NEW ENGLAND JOURNAL OF MEDICINE Hammer, S. M., Katzenstein, D. A., Hughes, M. D., Gundacker, H., Schooley, R. T., Haubrich, R. H., Henry, W. K., Lederman, M. M., Phair, J. P., Niu, M., Hirsch, M. S., Merigan, T. C., Blaschke, T. F., Simpson, D., McLaren, C., ROONEY, J., Salgo, M. 1996; 335 (15): 1081-1090
  • Human immunodeficiency virus in plasma and genital secretions during the menstrual cycle JOURNAL OF INFECTIOUS DISEASES Goulston, C., Stevens, E., Gallo, D., Mullins, J. I., Hanson, C. V., KATZENSTEIN, D. 1996; 174 (4): 858-861

    Abstract

    Six human immunodeficiency virus (HIV)-positive women were studied weekly over 8 weeks to detect HIV RNA in plasma and cervical secretions and proviral DNA in cervical, vaginal, and cervicovaginal lavage samples by polymerase chain reaction (PCR) amplification techniques. In cervical swab samples, cell-free HIV RNA was detected more frequently than cell-associated HIV proviral DNA (22/48 vs. 7/48, respectively). Cervical HIV RNA was consistently detected in 2 women with plasma HIV RNA > 100,000 copies/mL but was not detected in 2 women with plasma HIV RNA < 10,000 copies/mL, regardless of menstruation status. HIV-specific IgA was detected in the plasma of 2 women and in at least 1 cervicovaginal lavage sample from all 6 women. Thus, quantitation of cervical HIV RNA can be accomplished by PCR techniques and may be useful in evaluation genital viral shedding.

    View details for Web of Science ID A1996VK04500028

    View details for PubMedID 8843230

  • Polyethylene glycol-modified interleukin-2 and thymosin alpha(1) in human immunodeficiency virus type 1 infection JOURNAL OF INFECTIOUS DISEASES Ramachandran, R., Katzenstein, D. A., Winters, M. A., Kundu, S. K., Merigan, T. C. 1996; 173 (4): 1005-1008

    Abstract

    The safety and antiviral effects of polyethylene glycolated interleukin-2 (PEG-IL-2) and thymosin alpha 1 in addition to zidovudine were studied in 12 human immunodeficiency virus (HIV)-infected subjects with 50-250 CD4 T cells/mm3. PEG-IL-2 was administered by intravenous infusions every 2 weeks at 10(6) IU/m2 for 20 weeks. Thymosin alpha 1 was administered subcutaneously at 400 microgram/m2 after four doses of PEG-IL-2, escalating to 1600 microgram/m2 weekly for an additional 2 months. Significant elevations of CD4 T cell numbers of 30%-40% were seen after PEG-IL-2 infusions, but no additional increase in CD4 cell count was observed with thymosin alpha 1. Virologic monitoring by polymerase chain reaction quantitation of proviral DNA and plasma RNA and p24 antigen assays showed no evidence of increased HIV activation during PEG-IL-2 or thymosin alpha 1 therapy. Patients tolerated both PEG-IL-2 and thymosin alpha 1 without significant toxicities.

    View details for Web of Science ID A1996UB27400032

    View details for PubMedID 8603940

  • DRUG-RESISTANCE AND HETEROGENEOUS LONG-TERM VIROLOGICAL RESPONSES OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE 1-INFECTED SUBJECTS TO ZIDOVUDINE AND DIDANOSINE COMBINATION THERAPY JOURNAL OF INFECTIOUS DISEASES Shafer, R. W., Iversen, A. K., Winters, M. A., Aguiniga, E., Katzenstein, D. A., Merigan, T. C. 1995; 172 (1): 70-78

    Abstract

    Plasma human immunodeficiency virus (HIV) type 1 RNA levels, CD4 lymphocyte changes, and drug resistance were studied in HIV-infected patients with 200-500 CD4 lymphocytes/microL who received zidovudine and didanosine combination therapy for 2 years. Among 35 patients, 10 had sustained and 16 had transient > 10-fold reductions in HIV RNA: 9 did not have 10-fold HIV RNA reductions. Only patients with sustained HIV suppression maintained increased CD4 cell counts for 2 years (370 to 501 cells/microL; P = .006). Patients with transient HIV suppression were more likely to develop drug-resistant HIV strains (12/16 vs. 5/19, P = .01) and reverse transcriptase (RT) mutations (4.5 vs. 2.5/strain; P = .02) than were patients with sustained or no HIV suppression. Zidovudine resistance occurred with RT mutations at codons 41, 67, 70, 215, and 219. Multidrug resistance occurred with mutations at codons 62, 75, 77, 116, and 151. Mutations occurred at codons 60, 68, 118, 210, and 228 in > or = 4 patients each. Heterogeneity exists among individual virologic responses to zidovudine and didanosine combination therapy. HIV resistance mechanisms during combination therapy appear more complex than reported with monotherapy.

    View details for Web of Science ID A1995RF04100010

    View details for PubMedID 7541064

  • HIV viral load quantification, HIV resistance, and antiretroviral therapy. AIDS clinical review Katzenstein, D. A., Holodniy, M. 1995: 277-303

    Abstract

    We are moving rapidly beyond a "black box" understanding of the pathogenesis of HIV. The sites of virus replication, the molecular regulation of virus production in the host, and the dynamics between productive virus infection and immunological and clinical events are areas of intense study using powerful new tools. The quantitation of virus load and genetic characterization of replicating virus has important implications for the development and evaluation of drugs and treatment strategies for HIV. As new compounds are introduced, their ability to reduce virus load in vivo has become a primary consideration in the decision to initiate large efficacy trials and may soon be used, in combination with other markers, in the licensing of new agents. In parallel, rapid molecular evaluation of virus from patients, targeting those who break through drug-induced suppression, provides an explanation for the failure of drugs to sustain an effect on virus load. This approach has compressed the process of drug evaluation and set the stage for the evaluation of complex combinations and sequences of drugs to maintain suppression of virus and prevent the development of drug resistance. The most controversial question for the next few years is whether the measurement of virus load or detection of drug resistance can be incorporated into the practice of medicine and the management of individual patients. There is evidence that changes in virus load are the most proximate markers of drug response and that detection of resistance mutations can predict clinical and immunological decline. However, the window of time between a change in load or the development of drug resistance and a decline in CD4 cells is relatively short. With dideoxynucleoside therapies, a CD4 cell decline follows a rise in virus load or development of resistance within 3-6 months. In early studies with protease inhibitors and nonnucleoside reverse transcriptase inhibitors, the development of resistance and a return to baseline of virus load may occur within 2-3 months, mirrored by a fall in CD4 cells. The challenge to investigators is how to best use these new tools to determine whether changes or additions in therapy, initiated on the basis of virological measurements, result in more effective management of disease.

    View details for PubMedID 7488557

  • VIRAL PHENOTYPE AND GENOTYPE AS MARKERS IN CLINICAL-TRIALS 1st Annual Symposium on Surrogate Markers of HIV - Strategies and Issues for Selection and Use Katzenstein, D. A. LIPPINCOTT WILLIAMS & WILKINS. 1995: S25?S34

    Abstract

    Treatment of AIDS and HIV infection is increasingly dependent on the use of surrogate markers to assess the efficacy of drug and biologic therapies in individual patients and in the clinical trials. Recent developments in laboratory techniques have resulted in new assays to measure circulating viral RNA in HIV-infected individuals, standardized methods to assess genotypic changes in virus associated with drug resistance and biologic assays for syncytia-inducing phenotype, a viral characteristic associated with rapid clinical progression. Studies from our laboratory have examined the relationship between surrogate markers of drug efficacy, CD4 cell changes, quantitative HIV plasma RNA and cell dilution cultures, genotypic changes associated with drug resistance and the syncytia-inducing phenotype. The results of these studies suggest that drug-resistance genotype and syncytia-inducing phenotype are independent factors that contribute to disease progression in patients receiving zidovudine. The design of studies of drugs and biologics for the treatment of HIV should include assessment of genotypic and phenotypic characteristics of HIV in addition to CD4 cell numbers and virus load.

    View details for Web of Science ID A1995TD18600005

    View details for PubMedID 7552510

  • FAILURE OF SHORT-TERM CD4-PE40 INFUSIONS TO REDUCE VIRUS LOAD IN HUMAN IMMUNODEFICIENCY VIRUS-INFECTED PERSONS JOURNAL OF INFECTIOUS DISEASES Ramachandran, R. V., Katzenstein, D. A., Wood, R., Batts, D. H., Merigan, T. C. 1994; 170 (4): 1009-1013

    Abstract

    The safety, immunologic, and antiviral effects of a recombinant biologic product that combines the second and third domains of the CD4 molecule and Pseudomonas exotoxin A (PE40) were evaluated in 21 human immunodeficiency virus (HIV)-infected subjects in a phase III open-label dose-ranging study. Subjects with CD4+ lymphocyte counts of 100-500/mm3 received CD4-PE40 at 40, 80, or 160 micrograms/m2 by infusion three to seven times over 10 days. At the maximum tolerated dose (80 micrograms/m2), peak CD4-PE40 levels were 65-130 ng/mL with a serum half-life of 3.6 +/- 1.5 h. Toxicity, primarily increased hepatic transaminases, was dose-related and reversible. HIV DNA proviral levels in peripheral blood mononuclear cells and plasma HIV RNA remained stable during and after CD4-PE40 infusions. The relative resistance of clinical isolates of HIV, limits of the tolerated dose, and the immunogenicity and short half-life of the protein may explain the lack of in vivo antiviral effect of CD4-PE40.

    View details for Web of Science ID A1994PJ69400041

    View details for PubMedID 7930696

  • DIDANOSINE RESISTANCE IN HIV-INFECTED PATIENTS SWITCHED FROM ZIDOVUDINE TO DIDANOSINE MONOTHERAPY ANNALS OF INTERNAL MEDICINE Kozal, M. J., Kroodsma, K., Winters, M. A., Shafer, R. W., Efron, B., Katzenstein, D. A., Merigan, T. C. 1994; 121 (4): 263-268

    Abstract

    To determine the frequency and pattern of development of specific drug resistance mutations for human immunodeficiency virus (HIV) reverse transcriptase in patients switched from zidovudine to didanosine therapy and to examine the relation of the didanosine resistance mutation at codon 74 of the HIV reverse-transcriptase gene to CD4+ T-cell changes and virus burden.Retrospective analysis of all patients enrolled at Stanford University in protocols where patients were switched from zidovudine to didanosine monotherapy.A university hospital.64 patients infected with HIV who were switched from zidovudine to didanosine monotherapy. Patients had the acquired immunodeficiency syndrome (AIDS), AIDS-related complex, or were asymptomatic (mean [+/- SD] starting CD4+ T-cell count of 129 +/- 88 cells/mm3).Serial serum specimens were tested for the didanosine resistance mutation at codon 74 of the HIV reverse-transcriptase gene and for a zidovudine resistance mutation at codon 215 using selective polymerase chain reactions (PCR). Serum HIV RNA levels were determined by quantitative PCR. CD4+ T-cell counts were determined at serial time points.By 24 weeks of didanosine therapy, the proportion of patients with the didanosine resistance mutation at codon 74 increased from 0% to 56% (36 of 64). In contrast, the proportion of patients with the zidovudine resistance mutation at codon 215 decreased from 84% at the start to 59% after 24 weeks of didanosine therapy (a 25% decrease, 95% lower CI, 15%; P < 0.0001). Patients who developed the codon 74 mutation had a greater decrease in CD4+ T cells after the development of the mutation than did patients without the mutation (P < 0.001). In addition, after 24 weeks of didanosine, patients who developed the codon 74 mutation had a greater serum HIV RNA burden than patients who remained wild type (did not have the mutation) at codon 74 (225,000 compared with 82,400 HIV RNA copies/mL serum; P = 0.01).Among patients infected with HIV who had advanced disease and were switched from zidovudine to didanosine therapy, more than one half developed the didanosine resistance mutation at codon 74 by 24 weeks of didanosine therapy. Patients who developed the codon 74 mutation had a greater decline in CD4+ T cells after the development of the mutation and had a greater serum virus burden than did patients without the codon 74 mutation.

    View details for Web of Science ID A1994PB10200005

    View details for PubMedID 7518658

  • HIV-1 SYNCYTIUM-INDUCING PHENOTYPE, VIRUS BURDEN CODON-215 REVERSE-TRANSCRIPTASE MUTATION AND CD4 CELL DECLINE IN ZIDOVUDINE-TREATED PATIENTS JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES AND HUMAN RETROVIROLOGY Kozal, M. J., Shafer, R. W., Winters, M. A., Katzenstein, D. A., Aguiniga, E., Halpern, J., Merigan, T. C. 1994; 7 (8): 832-838

    Abstract

    The variable rate of disease progression in HIV-1-infected patients treated with zidovudine may be related to certain viral characteristics, such as, antiviral drug resistance, virus burden, and viral syncytium-inducing (SI) capacity. Thirty-two HIV-1-infected patients treated with zidovudine (mean of 34 months) were studied to determine the relationship of SI phenotype and the codon 215 pol gene mutation (a marker of zidovudine resistance) to virus burden and CD4 cell decline. Patients with SI strains and the codon 215 mutation in their proviral DNA had a 54% decline in CD4 cells and a virus burden of 21,480 proviral DNA copies/10(6) CD4 cells. In contrast, patients with non-SI (NSI) strains and wild-type at codon 215 had a 10% increase in CD4 cells and had a viral burden 1/46 that of patients with SI and the 215 mutation. Among patients with NSI strains, changes in CD4 cells depended on the presence of the codon 215 mutation (-160 CD4 cells/microliters), compared with those wild-type at codon 215 (+28 CD4 cells/microliters) (p < 0.01). There was a concordant rise in virus burden between proviral DNA and plasma HIV RNA depending on HIV phenotype and genotype. Using multiple linear regression, SI phenotype and the codon 215 mutation were found to independently predict CD4 cell decline and increased virus burden in zidovudine-treated patients.

    View details for Web of Science ID A1994NX17100007

    View details for PubMedID 7517448

  • COMBINATION THERAPY WITH ZIDOVUDINE AND DIDANOSINE SELECTS FOR DRUG-RESISTANT HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 STRAINS WITH UNIQUE PATTERNS OF POL GENE-MUTATIONS JOURNAL OF INFECTIOUS DISEASES Shafer, R. W., Kozal, M. J., Winters, M. A., Iversen, A. K., Katzenstein, D. A., Ragni, M. V., Meyer, W. A., Gupta, P., Rasheed, S., COOMBS, R., Katzman, M., Fiscus, S., Merigan, T. C. 1994; 169 (4): 722-729

    Abstract

    Drug resistance conferred by specific human immunodeficiency virus type 1 (HIV-1) pol gene mutations has been associated with clinical progression in HIV-infected patients receiving anti-retroviral therapy. This study examined drug susceptibilities and pol mutations of HIV-1 strains from patients treated for 1 year with zidovudine, didanosine (ddI), or zidovudine and ddI. Ten (42%) of 24 patients receiving combination therapy versus 8/26 (31%) receiving only zidovudine had HIV-1 strains with phenotypic zidovudine resistance or a zidovudine resistance pol mutation at codon 215 (P = .6). In contrast, a ddI resistance mutation at codon 74 was less common among patients receiving combination therapy (2/24) than among those receiving ddI only (17/26; P < .001). Two patients receiving combination therapy developed resistance to zidovudine and ddI; they had HIV strains with amino acid mutations at codons 62, 75, 77, 116, and 151. Combination therapy with zidovudine and ddI selects for zidovudine-resistant HIV-1 strains lacking a ddI resistance mutation and for multidrug-resistant strains containing novel pol mutations.

    View details for Web of Science ID A1994NP11100002

    View details for PubMedID 8133086

  • QUANTITATION OF HUMAN-IMMUNODEFICIENCY-VIRUS BY CULTURE AND POLYMERASE CHAIN-REACTION IN RESPONSE TO DIDANOSINE AFTER LONG-TERM THERAPY WITH ZIDOVUDINE JOURNAL OF INFECTIOUS DISEASES Katzenstein, D. A., Winters, M., BUBP, J., Israelski, D., Winger, E., Merigan, T. C. 1994; 169 (2): 416-419

    Abstract

    Measurements of human immunodeficiency virus by quantitative RNA and DNA polymerase chain reaction (PCR), cell and plasma infectivity dilution cultures, and immune complex-disassociated p24 antigen-capture ELISA were made repeatedly in 10 subjects receiving long-term zidovudine treatment before and after therapy was changed to didanosine. Comparison of baseline assays showed that quantitative cell cultures, plasma RNA, and proviral DNA were measurable in all subjects and that cell culture results were significantly correlated with measures of nucleic acids. Plasma viremia (as indicated by culture) and p24 antigen were detected in three measurements in 3 of 8 and 6 of 10 subjects, respectively. Significant decreases in plasma RNA and cell dilution cultures from baseline were maintained for up to 6 months after initiation of didanosine therapy. These findings demonstrate a decrease in virus burden with the use of didanosine; however, continued detection of plasma RNA suggests that additional antiviral therapy will be required to suppress viral replication.

    View details for Web of Science ID A1994MV82900028

    View details for PubMedID 7906292

  • BIOLOGICAL VARIATION AND QUALITY-CONTROL OF PLASMA HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 RNA QUANTITATION BY REVERSE-TRANSCRIPTASE POLYMERASE CHAIN-REACTION JOURNAL OF CLINICAL MICROBIOLOGY Winters, M. A., Tan, L. B., Katzenstein, D. A., Merigan, T. C. 1993; 31 (11): 2960-2966

    Abstract

    Quantitation of human immunodeficiency virus type 1 (HIV-1) RNA in the plasma of seropositive individuals was performed by using an external control assay with techniques to standardize and control each measurement. Rigorous study of the variability of the assay showed that the median intraassay reproducibility was log10 0.15 RNA copies per ml of plasma, while the median interassay reproducibility on replicate plasma samples was log10 0.25 copies perml. Specimen stability studies showed reproducible recovery of RNA from plasma stored at -70 degrees C for up to 12 months. In clinically stable patients who were either untreated or taking zidovudine, the average week-to-week variation in plasma RNA levels, measured in real time, was log10 0.30 RNA copies per ml. In contrast, patients either initiating or changing antiretroviral therapy showed a fall of log10 0.8 to log10 2.0 copies per ml in plasma RNA levels. Overall, 105 of 110 (96%) HIV-1-seropositive individuals with CD4 counts of 36 to 868 cells per mm3 had quantifiable HIV-1 RNA over a range of log10 2.70 to log10 6.23 RNA copies per ml, including 81% (13 of 16) of the individuals with greater than 500 CD4 cells per mm3. Accurate and reproducible quantitation of plasma viremia in real time by reverse transcriptase polymerase chain reaction, particularly in asymptomatic HIV-1-infected individuals with high CD4 counts, provides a basis for the use of this virologic measure to monitor the short- and long-term effects of early intervention therapeutic strategies on viral burden.

    View details for Web of Science ID A1993MC28900022

    View details for PubMedID 7903317

  • PERIPHERAL-BLOOD MONONUCLEAR CELL HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 PROVIRAL DNA QUANTIFICATION BY POLYMERASE CHAIN-REACTION - RELATIONSHIP TO IMMUNODEFICIENCY AND DRUG EFFECT JOURNAL OF CLINICAL MICROBIOLOGY Montoya, J. G., Wood, R., KATZENSTEIN, D., HOLODNY, M., Merigan, T. C. 1993; 31 (10): 2692-2696

    Abstract

    Human immunodeficiency virus type 1 (HIV-1) proviral DNA from peripheral blood mononuclear cells (PBMCs) was quantitated in 61 HIV-1-seropositive individuals by a nonisotopic polymerase chain reaction assay. Primers from the gag region (SK38, SK39) were used to determine the log10 HIV-1 proviral copy number per 10(6) CD4+ T lymphocytes (peripheral blood proviral load). A standard curve was generated for each assay by using ACH-2 cell DNA. The peripheral blood proviral load was followed in 15 individuals in a longitudinal study and was measured in 45 individuals in a cross-sectional analysis. Three of four untreated patients who were followed for 14 months had stable PBMC proviral loads and CD4+ T lymphocyte counts; one untreated patient had a sustained increase in PBMC proviral load followed 5 months later by a significant decline in the CD4+ T lymphocyte count. Eleven previously untreated individuals were monitored for 1 year following initiation of zidovudine and/or 2',3'-dideoxyinosine therapy. The mean log10 number of proviral HIV-1 copies per 10(6) CD4+ T cells decreased from 4.3 +/- 0.4 at the baseline to 3.5 +/- 0.6 after 2 to 4 months of therapy (P < 0.01). This initial 0.8 log10 fall in the PBMC proviral load after the initiation of therapy was followed by a rise in the PBMC proviral load by the sixth month of therapy. The PBMC proviral load in 45 subjects, both treated (n = 25) and untreated (n = 20), correlated inversely with the CD4+ T lymphocyte count (P < 0.01, R = 0.49). PBMC proviral DNA quantification by a nonisotopic polymerase chain reaction assay correlates with HIV-1 disease progression and could be used to monitor the effect of antiretroviral therapy.

    View details for PubMedID 7902845

  • MEASUREMENT OF HIV VIRUS LOAD AND GENOTYPIC RESISTANCE BY GENE AMPLIFICATION IN ASYMPTOMATIC SUBJECTS TREATED WITH COMBINATION THERAPY JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Holodniy, M., KATZENSTEIN, D., Winters, M., Montoya, J., Shafer, R., Kozal, M., Ragni, M., Merigan, T. C. 1993; 6 (4): 366-369

    Abstract

    Quantification of viral load in HIV disease has become increasingly important as a marker of antiviral efficacy. We applied gene amplification techniques in vivo to asses antiretroviral activity of combination therapy. Five HIV-infected subjects, four of whom were drug naive, were administered combination therapy with zidovudine (ZDV) and didanosine (ddI). Plasma and peripheral blood mononuclear cells (PBMC) were obtained twice at baseline and then at 1, 3, 6, 9, and 12 months after the initiation of therapy. Results show that plasma HIV RNA copy number fell from 2,170 +/- 660/ml to undetectable at 1 month, with continued suppression at 12 months. HIV proviral DNA copy number decreased from 3.9 to 3.0 log10/10(6) CD4+ T cells at 12 months. Cell dilution cultures were positive in 4 of 5 subjects at baseline and in only 1 of 5 after 12 months. CD4+ T-cell count increased from 390 +/- 30/mm3 pretherapy, to 505 +/- 66/mm3 after 6 months of therapy, but returned to baseline levels after 12 months of therapy. No mutations were detected from PBMC DNA for codon 215 and 74 in the HIV pol gene from the drug-naive subjects. These findings suggest that gene amplification techniques can be used to study changes in viral load or genotype and can be applied in real time to samples from patients involved in clinical trials.

    View details for Web of Science ID A1993KU22100007

    View details for PubMedID 8095981

  • DETECTION OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 IN SEMEN - EFFECTS OF DISEASE STAGE AND NUCLEOSIDE THERAPY JOURNAL OF INFECTIOUS DISEASES Hamed, K. A., Winters, M. A., Holodniy, M., Katzenstein, D. A., Merigan, T. C. 1993; 167 (4): 798-802

    Abstract

    The effects of clinical stage of infection and antiviral therapy on the detection of human immunodeficiency virus type 1 (HIV-1) nucleic acids in semen were investigated by the polymerase chain reaction. HIV-1 was detected in 45 (87%) of 52 semen specimens from 29 (81%) of 36 men. Seventeen (77%) of 22 stage II or III subjects and 12 (86%) of 14 stage IV subjects had positive specimens. The CD4+ lymphocyte count was not significantly different comparing subjects with positive and negative semen. Moreover, 6 (67%) of 9 untreated men had positive specimens compared with 23 (85%) of 27 men treated with zidovudine, 2',3'-dideoxyinosine, or both for a mean of 20 months. Thus, the detection of HIV-1 in semen was independent of both stage of infection and long-term treatment. In a semiquantitative analysis of 6 men followed for 8 weeks after the start of nucleoside therapy, a decrease in HIV-1 RNA in seminal plasma was demonstrated in 2.

    View details for Web of Science ID A1993KU08600002

    View details for PubMedID 8450243

  • A MUTATION IN HUMAN-IMMUNODEFICIENCY-VIRUS REVERSE-TRANSCRIPTASE AND DECLINE IN LYMPHOCYTE-CD4 NUMBERS IN LONG-TERM ZIDOVUDINE RECIPIENTS JOURNAL OF INFECTIOUS DISEASES Kozal, M. J., Shafer, R. W., Winters, M. A., Katzenstein, D. A., Merigan, T. C. 1993; 167 (3): 526-532

    Abstract

    A nested polymerase chain reaction assay was used to define the sequence of a specific codon, amino acid 215, of the human immunodeficiency virus (HIV) pol gene in DNA from peripheral blood mononuclear cells (PBMC) and viral RNA from serum from 38 patients treated with zidovudine for > or = 2 years. After treatment for a mean of 34 months, 17 patients with sequences with a codon 215 mutation had a mean 50% decrease in CD4 cells, compared with 21 patients with sequences wild-type at codon 215, who had a mean 11% increase in CD4 cells (P < .0001). Patients with a mutation at 215 had a ninefold higher provirus burden in PBMC. Detection of the codon 215 mutation in plasma viral RNA preceded detection of the mutation in DNA from PBMC and decline in CD4 cells. The appearance of a mutation at codon 215 in the HIV reverse transcriptase gene in patients receiving zidovudine may be a marker for impending immunologic decline.

    View details for Web of Science ID A1993KN15200002

    View details for PubMedID 7680058

  • ZIDOVUDINE SUSCEPTIBILITY TESTING OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 (HIV) CLINICAL ISOLATES JOURNAL OF VIROLOGICAL METHODS Shafer, R. W., Kozal, M. J., Katzenstein, D. A., LIPIL, W. H., JOHNSTONE, I. F., Merigan, T. C. 1993; 41 (3): 297-310

    Abstract

    Traditional antiviral susceptibility testing methods using cell lines can be applied to no more than about 30% of clinical HIV isolates (Larder et al., 1989a; Fenyo et al., 1989). We tested the cell-free supernatant from low passage clinical HIV isolates using donor peripheral blood mononuclear cells (PBMC). Drug susceptibility was assessed by measuring the effect of increasing zidovudine (ZDV) concentrations on HIV P24 antigen production. Susceptibility results were obtained on 24/27 consecutive clinical isolates and 6/6 laboratory isolates. The mean IC90 of isolates from untreated patients was 0.008 microM ZDV (range: 0.002-0.038). The IC90s of isolates from ZDV-treated patients ranged from 0.007 to greater than 10 microM ZDV. All isolates with an IC90 < 0.1 microM ZDV had a wild type sequence at codon 215 of the HIV pol gene; 11/12 isolates with an IC90 > 0.1 microM ZDV had a mutation at codon 215 (P < 0.001). Among 16 ZDV-treated patients, there was a modest correlation between the change in CD4 count from the start of ZDV treatment and the IC90 of the patient's isolate following treatment (r = 0.51). Susceptibility testing using donor PBMC can be a sensitive means of testing a broad range of clinical HIV isolates.

    View details for Web of Science ID A1993KR99500004

    View details for PubMedID 8097199

  • QUANTIFICATION AND COMPARISON OF HIV-1 PROVIRAL LOAD IN PERIPHERAL-BLOOD MONONUCLEAR-CELLS AND ISOLATED CD4+ T-CELLS JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES Wood, R., Dong, H. L., Katzenstein, D. A., Merigan, T. C. 1993; 6 (3): 237-240

    Abstract

    HIV proviral load was determined by quantitative DNA polymerase chain reaction (PCR) in peripheral blood mononuclear cells (PBMC) and lymphocyte subsets isolated by cell sorter. Provirus measured in PBMC, when expressed as HIV copy number per million CD4+ cells, resulted in values which approximated those obtained from sorted CD4+ T lymphocytes. A cross sectional analysis of HIV proviral load in CD4+ T cells from 25 previously untreated and 30 zidovudine-treated seropositive patients with CD4+ T-cell counts between 25 and 802/mm3 demonstrated HIV copy numbers ranging from 1 copy per 10,000 cells in early disease to 1 copy per 10 cells in advanced disease. HIV proviral load can be rapidly assayed by PCR to give a reproducible value which varies over a 1,000-fold range and is positively correlated with cell infectivity as measured by a quantitative micrococulture assay. A less technically demanding assay using PBMC as substrate can give similar results to those obtained with sorted CD4+ T cells.

    View details for Web of Science ID A1993KN54200004

    View details for PubMedID 8450397

  • ENHANCEMENT OF HUMAN-IMMUNODEFICIENCY-VIRUS (HIV)-SPECIFIC CD4+ AND CD8+ CYTOTOXIC LYMPHOCYTE-T ACTIVITIES IN HIV-INFECTED ASYMPTOMATIC PATIENTS GIVEN RECOMBINANT GP160 VACCINE PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Kundu, S. K., KATZENSTEIN, D., Moses, L. E., Merigan, T. C. 1992; 89 (23): 11204-11208

    Abstract

    Twenty-six human immunodeficiency virus (HIV)-infected asymptomatic patients with CD4+ lymphocytes > 400 per mm3 were randomly allocated to a range of doses of recombinant gp160 or a control (recombinant hepatitis B vaccine) on a double-blind basis. Each patient received an injection at 0, 4, 12, 24, 36, and 48 weeks. Treatment assignments were decoded when all patients reached 28 weeks of the study period. HIV-1-specific CD4+ and CD8+ cytotoxic T lymphocyte (CTL) activities were assessed in vitro before vaccination and 2 weeks after each injection. There were significant increases in major histocompatibility complex-restricted HIV-1 Env-specific CD4+ and CD8+ CTL activities in 18 of 21 gp160 vaccinees. No control-injected patients showed a significant change. Neither gp160 nor control recipients showed significant changes in HIV-1 Gag- and Pol-specific CTL activities. HIV-1 Env-specific CD4+ and CD8+ CTL precursor frequencies were also measured in three vaccinees before and at 24 weeks after vaccine was started. CTL precursor frequencies also increased in both CD4+ and CD8+ populations. This study shows that this gp160 vaccine is immunogenic in enhancing HIV-1 Env-specific cytotoxic T-cell-mediated immunity in HIV-seropositive individuals.

    View details for Web of Science ID A1992KA90300022

    View details for PubMedID 1360665

  • Quantitative RNA and DNA gene amplification can rapidly monitor HIV infection and antiviral activity in cell cultures. PCR methods and applications Winters, M. A., Holodniy, M., Katzenstein, D. A., Merigan, T. C. 1992; 1 (4): 257-262

    Abstract

    We have developed a quantitative gene amplification procedure to assess the replication of human immunodeficiency virus (HIV) in cell cultures and evaluate the effect of drugs on viral replication. Increases in HIV gag RNA and DNA in phytohemagglutinin-stimulated normal peri-pheral blood mononuclear cells (PBMC) infected with HIV at very low multiplicity of infection paralleled the production of HIV p24 antigen in culture supernatants. Quantitative gene amplification was able to monitor the accumulation of viral nucleic acids in control cultures and demonstrate the effect of various concentrations of azidothymidine (AZT) on the replication of both AZT-sensitive and -resistant strains of HIV. The sensitivity of patient-derived virus strains to AZT could also be successfully measured by these procedures. The results of our studies suggest that quantitative measurement of HIV gag RNA and DNA can be used to monitor the kinetics of viral replication, antiviral activity, viral drug resistance, and mechanism of drug action.

    View details for PubMedID 1477661

  • PLASMA VIREMIA IN HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION - RELATIONSHIP TO STAGE OF DISEASE AND ANTIVIRAL TREATMENT JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES AND HUMAN RETROVIROLOGY Katzenstein, D. A., Holodniy, M., Israelski, D. M., Sengupta, S., Mole, L. A., BUBP, J. L., Merigan, T. C. 1992; 5 (2): 107-112

    Abstract

    Quantitative culture of human immunodeficiency virus (HIV) was performed on 121 plasma samples from 76 HIV-infected individuals to determine the sensitivity of the assay at different stages of disease and to measure the effect of antiviral therapy on plasma viremia. Plasma virus was detected in 49 of 76 (64%) of patients, primarily those with AIDS and AIDS-related complex (36 of 38) versus asymptomatic subjects (13 of 38) (p less than 0.001, chi 2). Similarly, plasma cultures were more often positive in patients with less than 250 CD4+ T cells per microliter (38 of 40) than in those with greater than 250 CD4+ T cells per microliter (11 of 36) (p less than 0.001, chi 2). Plasma virus cultures were also more likely to be positive in patients with detectable serum p24 antigen (24 of 26) than in those without detectable p24 antigen (25 of 50) (p = 0.0023, chi 2). An effect of zidovudine (ZDV) treatment on plasma viremia was seen in a comparison of treated and untreated patients with less than 250 CD4+ T cells per microliter. Geometric mean titers of plasma viremia from 16 patients treated with ZDV for more than 3 months were significantly lower than titers from 24 untreated patients (10(1.3) versus 10(2.1), p less than 0.05, Student's t test. A comparison of pre- and posttherapy titers in 33 patients receiving antiviral treatment showed that plasma virus was not detectable at either time in 17 patients; there was a fall in plasma virus titer in 12; and titers were unchanged or increased in 4. In patients with advanced disease, plasma viremia is a potential marker of antiviral drug activity.

    View details for Web of Science ID A1992GZ90200001

    View details for PubMedID 1732501

  • DECREASE IN HIV PROVIRUS IN PERIPHERAL-BLOOD MONONUCLEAR-CELLS DURING ZIDOVUDINE AND HUMAN RIL-2 ADMINISTRATION JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES AND HUMAN RETROVIROLOGY Clark, A. G., Holodniy, M., Schwartz, D. H., Katzenstein, D. A., Merigan, T. C. 1992; 5 (1): 52-59

    Abstract

    Quantification of human immunodeficiency virus (HIV) proviral DNA in peripheral blood mononuclear cells (PBMC) was performed in 13 HIV-seropositive asymptomatic individuals during 10-24 months by polymerase chain reaction amplification of multiple half-log dilutions of cellular DNA. At enrollment, subjects had a geometric mean titer of 100 copies of HIV provirus per 10(6) PBMC (mean +/- SD, 2 +/- 0.9 log10). In four untreated individuals there was no significant change in provirus levels during a mean period of 13.3 months. In eight patients treated with zidovudine (ZDV) and human recombinant interleukin 2 (rIL-2), HIV provirus copies declined to 13 per 10(6) cells (1.1 +/- 0.8 log10) at the end of the first course of ZDV and rIL-2 at week 20 (p less than 0.01), and to 40 per 10(6) cells (1.6 +/- 0.9 log10) after 12 months of treatment (p less than 0.04). Subsequent courses, which included 12 weeks of ZDV alone or 4 weeks of IL-2 alone, did not significantly change the already depressed provirus copy numbers. Proviral copy number also remained depressed during drug-free "washout periods" between courses. Finally, we observed a return to a geometric mean of 400 copies per 10(6) cells (2.6 +/- 0.3 log10) a mean of 7.9 months after discontinuation of therapy. Measurement of changes in HIV provirus should provide a direct marker for defining antiviral activity of drugs, biologics, and combination therapy.

    View details for Web of Science ID A1992GW91300009

    View details for PubMedID 1738087

  • Quantitative virological measures of antiretroviral therapy. AIDS clinical review Katzenstein, D. A., Holodniy, M. 1992: 41-67

    View details for PubMedID 1376615

  • REDUCTION IN PLASMA HUMAN-IMMUNODEFICIENCY-VIRUS RIBONUCLEIC-ACID AFTER DIDEOXYNUCLEOSIDE THERAPY AS DETERMINED BY THE POLYMERASE CHAIN-REACTION JOURNAL OF CLINICAL INVESTIGATION Holodniy, M., Katzenstein, D. A., Israelski, D. M., Merigan, T. C. 1991; 88 (5): 1755-1759

    Abstract

    Cell-free HIV RNA in plasma was detected and quantitated after antiviral therapy by the polymerase chain reaction. RNA was extracted from plasma, reverse transcribed to cDNA, amplified by polymerase chain reaction, and quantitated by absorbance based on an enzyme-linked affinity assay. 72 HIV antibody-positive subjects had one plasma sample taken. 39 who were not receiving antiretroviral therapy at the time had a mean plasma HIV RNA copy number of 690 +/- 360 (mean +/- SEM) per 200 microliters of plasma, while 33 subjects who had been receiving zidovudine therapy for a minimum of 3 mo had a mean copy number of 134 +/- 219 (P less than 0.05). 27 additional HIV antibody-positive patients had two plasma samples taken before and 1 mo after initiating dideoxynucleoside therapy. Plasma HIV RNA copy number fell from 540 +/- 175 to 77 +/- 35 (P less than 0.05). Finally, nine of these subjects had two baseline samples obtained before initiating therapy and two posttreatment samples 1 and 2 mo after therapy was begun. Mean plasma RNA copy number declined from 794 +/- 274 to less than 40 (below the lower limit of sensitivity) after 1 mo of therapy, with suppression maintained after 2 mo of therapy. These results suggest that gene amplification can be used to detect and quantitate changes in plasma HIV RNA after dideoxynucleoside therapy. Plasma HIV polymerase chain reaction may be a more sensitive marker to monitor antiviral therapy, particularly in asymptomatic patients where measurement of p24 antigen or quantitative plasma cultures are negative.

    View details for Web of Science ID A1991GN72700044

    View details for PubMedID 1682345

  • DETECTION OF HUMAN-IMMUNODEFICIENCY-VIRUS DNA AND RNA IN SEMEN BY THE POLYMERASE CHAIN-REACTION JOURNAL OF INFECTIOUS DISEASES Mermin, J. H., Holodniy, M., Katzenstein, D. A., Merigan, T. C. 1991; 164 (4): 769-772

    Abstract

    Peripheral blood mononuclear cells (PBMC) and semen of 23 men infected with human immunodeficiency virus (HIV) were examined for the presence of HIV DNA and RNA using the polymerase chain reaction (PCR) and a nonisotopic detection assay. None of the men was receiving antiretroviral therapy at the time of collection. Semen samples were separated into cell-free seminal fluid, nonspermatozoal mononuclear cells (NSMC), and spermatozoa. All of the PBMC samples, 17 (74%) of 23 NSMC samples, and none of the spermatozoal samples were positive for HIV gag gene DNA. Of 23 cell-free seminal fluid samples, 15 (65%) were positive for HIV gag gene RNA by PCR. Cell-free HIV RNA was more likely to be present in the semen of men with less than 400 than in those with greater than or equal to 400 cells/mm3 (P less than .04) and was present in all patient with p24 antigen in serum. The presence of HIV DNA in NSMC samples was not related to CD4 cell count, disease status, or the presence of p24 antigen in the serum. This study shows that HIV nucleic acid can be detected by PCR in either the cell-free seminal fluid or NSMC of 87% of semen samples but not in the DNA of spermatozoa from HIV-infected men.

    View details for Web of Science ID A1991GF80500022

    View details for PubMedID 1680138

  • INHIBITION OF HUMAN-IMMUNODEFICIENCY-VIRUS GENE AMPLIFICATION BY HEPARIN JOURNAL OF CLINICAL MICROBIOLOGY Holodniy, M., Kim, S., KATZENSTEIN, D., Konrad, M., Groves, E., Merigan, T. C. 1991; 29 (4): 676-679

    Abstract

    Gene amplification of virus-specific sequences is widely used as a method to detect or confirm human immunodeficiency virus (HIV) infection. In this study we used an enzyme-linked affinity assay to quantify polymerase chain reaction products from whole blood, plasma, and separated mononuclear cells collected in the presence of four common anticoagulants: acid citrate dextrose, sodium EDTA, potassium oxalate, and sodium heparin. Attenuation of the product signal was observed after amplification of nucleic acid extraction from whole blood, washed mononuclear cells, and plasma from specimens collected in sodium heparin. These inhibitory effects on gene amplification could be reversed with heparinase. The addition of as little as 0.05 U of heparin completely inhibited amplification of an HLA-DQa sequence from placental DNA. We conclude that heparin can cause attenuation or inhibition of gene amplification. Acid citrate dextrose and EDTA, which lack inhibitory activity, are the most appropriate anticoagulants for clinical blood samples when polymerase chain reaction amplification is anticipated.

    View details for PubMedID 1909709

  • DETECTION AND QUANTIFICATION OF HUMAN-IMMUNODEFICIENCY-VIRUS RNA IN PATIENT SERUM BY USE OF THE POLYMERASE CHAIN-REACTION JOURNAL OF INFECTIOUS DISEASES Holodniy, M., Katzenstein, D. A., Sengupta, S., Wang, A. M., CASIPIT, C., Schwartz, D. H., Konrad, M., Groves, E., Merigan, T. C. 1991; 163 (4): 862-866

    Abstract

    Human immunodeficiency virus (HIV) RNA was detected and quantified in the serum of HIV-seropositive individuals using the polymerase chain reaction (PCR) and a nonisotopic enzyme-linked affinity assay. Of 55 HIV-infected patients who were not receiving therapy, serum HIV RNA was detected in 9 of 19 who were asymptomatic, 11 of 16 with AIDS-related complex (ARC), and 18 of 20 with AIDS, with copy numbers ranging from 10(2) to greater than or equal to 5 x 10(4) 200 microliters of serum based on a relationship between absorbance and known copy number of gag gene RNA. Linear regression analysis demonstrated a correlation between infectious titer in 42 patient sera cocultured with donor peripheral blood mononuclear cells (PBMC) and PCR product absorbance (r = .70, P less than .01). Serum HIV RNA detected by PCR also correlated with serum p24 antigen positivity, CD4 counts less than 400/mm3, and the presence of HIV-related symptoms or disease. Quantification of infectious HIV RNA in cell-free serum by PCR may be useful as a marker for for disease progression or in monitoring antiviral therapy.

    View details for Web of Science ID A1991FD93900031

    View details for PubMedID 2010639

  • RELATION OF THE PATHOGENESIS OF HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION TO VARIOUS STRATEGIES FOR ITS CONTROL REVIEWS OF INFECTIOUS DISEASES Merigan, T. C., Katzenstein, D. A. 1991; 13 (2): 292-302

    Abstract

    This paper reviews functionally important insights into the pathogenesis of human immunodeficiency virus (HIV) infection. The major sequela of this infection is early and progressive involvement of the immune system, with widespread immune dysfunction. This pathogenetic feature has a major impact on strategies for control of the infection. The immunosuppression caused by the virus leads to higher levels of viral replication and enhanced potential for development or selection of variant viruses, including forms that are more virulent or even drug resistant. Therefore, control of HIV infection and disease may require antiviral agents and CD4 receptor competitors as well as recombinant DNA-derived lymphokines and subunit vaccine immunotherapies. To be successful, such therapies must work to counter infection in monocytes and nonlymphoid cells as well as in T4 lymphocytes. Because many limbs of the immune system are affected by HIV infection, the complexities of this pathogen can be unraveled only by the careful study of immune functions during the disease and of effective interventions to control infection and disease and to restore immune functions.

    View details for Web of Science ID A1991FD04700018

    View details for PubMedID 2041962

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