Bio

Clinical Focus


  • Anatomic Pathology
  • Renal Pathology
  • Medical Liver Pathology

Academic Appointments


Administrative Appointments


  • Associate Chair for Residency Training, Pathology (2012 - Present)
  • Program Director for Anatomic & Clinical Pathology, Pathology (2012 - Present)
  • Associate Program Director, Anatomic Pathology (2010 - 2012)
  • Co-Director, Renal Pathology & Electron Microscopy Lab (2008 - Present)

Honors & Awards


  • Resident Teaching Award, Department of Pathology (2009)
  • Excellence in Teaching, Stanford Medical Student Education (2008)
  • Teaching Award, Nephrology Division, Department of Medicine (2007)

Professional Education


  • Residency:Columbia University (2000) NY
  • Residency:Stanford University School of Medicine (2001) CA
  • Board Certification: Anatomic Pathology, American Board of Pathology (1999)
  • Internship:Maricopa Medical Center (1995) AZ
  • Medical Education:Osmania General Hospital (1992) India
  • -, Stanford University, Surgical Pathology Fellowship (2001)
  • -, Columbia University, NY, Renal Pathology Fellowship (2000)
  • -, Columbia University, NY, Anatomic Pathology Residency (1999)

Research & Scholarship

Current Research and Scholarly Interests


Research interests primarily involve medical diseases and transplantation pathology of the kidney and liver.

Teaching

2013-14 Courses


Publications

Journal Articles


  • Acute transplant glomerulopathy with monocyte rich infiltrate. Transplant immunology Lenihan, C. R., Tan, J. C., Kambham, N. 2013; 29 (1-4): 114-117

    Abstract

    Acute transplant glomerulopathy refers to alloimmune mediated endothelial injury and glomerular inflammation that typically occurs early post-kidney transplantation. We report a case of a 48-year old woman with end stage renal disease from lupus nephritis who developed an unexplained rise in serum creatinine 2months after renal transplant. As immunosuppression, she received alemtuzumab induction followed by a tacrolimus, mycophenolate mofetil and prednisone maintenance regimen. Her biopsy revealed severe glomerular endothelial injury associated with monocyte/macrophage-rich infiltrate in addition to mild acute tubulointerstitial cellular rejection. We briefly discuss acute transplant glomerulitis, its pathology and association with chronic/overt transplant glomerulopathy, C4d negative antibody-mediated rejection and the significance of monocytes in rejection. We also postulate that alemtuzumab induction may have contributed to the unusual pattern of monocyte-rich transplant glomerulitis.

    View details for DOI 10.1016/j.trim.2013.09.004

    View details for PubMedID 24056179

  • BK Polyomavirus Subtype III in a Pediatric Renal Transplant Patient with Nephropathy. Journal of clinical microbiology Kapusinszky, B., Chen, S. F., Sahoo, M. K., Lefterova, M. I., Kjelson, L., Grimm, P. C., Kambham, N., Concepcion, W., Pinsky, B. A. 2013; 51 (12): 4255-4258

    Abstract

    BK polyomavirus (BKV) is an emerging pathogen in immunocompromised individuals. BKV subtype III is rarely identified and has not previously been associated with disease. Here we provide the whole-genome sequence of a subtype III BKV from a pediatric kidney transplant patient with polyomavirus-associated nephropathy.

    View details for DOI 10.1128/JCM.01801-13

    View details for PubMedID 24048534

  • A study of interobserver reproducibility of morphologic lesions of focal segmental glomerulosclerosis VIRCHOWS ARCHIV Meehan, S. M., Chang, A., Gibson, I. W., Kim, L., Kambham, N., Laszik, Z. 2013; 462 (2): 229-237

    Abstract

    The morphology of focal segmental glomerulosclerosis (FSGS) includes collapsing, cellular, and sclerosing forms. The Columbia Working Classification of FSGS divides these into collapsing (COLL), cellular (CELL), tip lesion (TIP), perihilar (PH), and not otherwise specified (NOS) morphologic forms. This study examined the ability of renal pathologists to classify FSGS using single light microscopic images of glomeruli as a uniform data set. Sixty-one digital images of individual glomeruli with FSGS, stained by periodic acid-Schiff or Jones methenamine silver methods, were classified independently by six specialist renal pathologists. Diagnostic consistency was quantified using the kappa statistic for nominal categories. Agreement for 366 diagnoses by six observers was 75.2 % with a kappa value of 0.676. Six of six observers agreed in 31 of 61 cases (50.8 %) and four or more in 53 cases (86.9 %). Respective kappa values ranged from moderate to good: COLL 0.77, CELL 0.53, TIP 0.76, PH 0.84, and NOS 0.60. Capillary retraction with lobular expansion, hypercellularity, and sclerosis in the same glomerular segments, and the location of segmental lesions were sources of diagnostic inconsistency. The morphologic forms of FSGS defined by the Columbia system are reproducible between observers and have a low probability of confusion between forms. Individual glomeruli may have overlapping features of more than one form of FSGS.

    View details for DOI 10.1007/s00428-012-1355-3

    View details for Web of Science ID 000314724300012

    View details for PubMedID 23262784

  • Fibronectin Glomerulopathy: An Unusual Cause of Adult-Onset Nephrotic Syndrome AMERICAN JOURNAL OF KIDNEY DISEASES Nadamuni, M., Piras, R., Mazbar, S., Higgins, J. P., Kambham, N. 2012; 60 (5): 839-842

    Abstract

    We report the case of a 50-year-old woman with nephrotic-range proteinuria and lobular glomerulopathy on kidney biopsy. Homogenous glomerular deposits were non-immune reactive, but immunofluorescence microscopy for fibronectin was strongly positive. Ultrastructurally, the deposits were granular with focal fibril formation, leading to a diagnosis of fibronectin glomerulopathy. Mutational analysis revealed a heterozygous missense mutation in fibronectin (leading to the tyrosine at amino acid 973 being replaced by cysteine [Y973C]), confirming the diagnosis. This mutation affects Hep-III, one of the heparin-binding domains of fibronectin, and results in functional abnormalities.

    View details for DOI 10.1053/j.ajkd.2012.04.029

    View details for Web of Science ID 000310508100037

    View details for PubMedID 22721928

  • Postinfectious Glomerulonephritis ADVANCES IN ANATOMIC PATHOLOGY Kambham, N. 2012; 19 (5): 338-347

    Abstract

    Postinfectious glomerulonephritis (PIGN) is an immunologically mediated glomerular injury triggered by an infection. Poststreptococcal glomerulonephritis (PSGN) is a classic example of PIGN with diffuse proliferative and exudative glomerular histology, dominant C3 staining and subepithelial "humps." Only the nephritogenic streptococcal infections cause PSGN and susceptibility to develop PSGN depends on both host and microbial factors. Over the last decade, two nephritogenic antigens, "nephritis-associated plasmin receptor" and "streptococcal pyrogenic exotoxin B" have been identified. PSGN is a self-limited disease, especially in children, but long-term follow-up studies indicate persistent low-grade renal abnormalities in a significant proportion of patients. PSGN continues to be a serious public health concern in third world countries, but the incidence of streptococcal infections has steadily declined in industrialized nations. PIGN in the western world is now primarily because of nonstreptococcal infections, often affecting older individuals with comorbidities such as diabetes mellitus or alcoholism, and is associated with poor outcomes. Although the acute PIGN has diffuse proliferative, focal segmental proliferative or mesangioproliferative patterns of glomerular injury, chronic or subacute infection-associated glomerulonephritis typically results in membranoproliferative appearance. PIGN has dominant C3 staining with frequent occurrence of subepithelial "humps" as well as subendothelial deposits. The immunoglobulin staining on immunofluorescence is typically weak, but immunoglobulin A-dominant PIGN is a recently defined entity often associated with staphylococcal infections. The wide spectrum of morphologic changes seen in PIGN poses a diagnostic challenge, especially if adequate clinical and serological data are lacking.

    View details for DOI 10.1097/PAP.0b013e31826663d9

    View details for Web of Science ID 000307875800006

    View details for PubMedID 22885383

  • Rituximab treatment for recurrence of nephrotic syndrome in a pediatric patient after renal transplantation for congenital nephrotic syndrome of Finnish type PEDIATRIC TRANSPLANTATION Chaudhuri, A., Kambham, N., Sutherland, S., Grimm, P., Alexander, S., Concepcion, W., Sarwal, M., Wong, C. 2012; 16 (5): E183-E187

    Abstract

    Congenital nephrotic syndrome (CNS) of the Finnish type due to mutation in the NPHS-1 gene results in massive proteinuria due to structural abnormality in the glomerular slit diaphragm, and is usually refractory to immunosuppressive therapy. Patients eventually require bilateral nephrectomy and renal replacement therapy, with transplantation being the ultimate goal. Post-transplant recurrence of nephrotic syndrome occurs in about 25% of children and is thought to be immune-mediated secondary to antibodies formed against the nephrin protein in renal allograft. Conventional therapy with calcineurin inhibitors (CNI), cyclophosphamide and corticosteroids with or without plasmapheresis often fails to achieve remission resulting in graft loss in 12-16%. There is limited experience with use of rituximab (RTX) in pediatric organ transplant recipients. We report the first case of post-transplant recurrence of nephrotic syndrome in a 4-yr-old child with CNS due to NPHS-1 mutation in whom CNI, corticosteroid and cyclophosphamide therapy was unsuccessful, but who achieved remission after depletion of B cells with RTX, associated with a decrease in the level of anti-nephrin antibodies. The child remains in remission 5 yr following treatment. Our experience suggests that activated B cells may play a pivotal role in the recurrence of nephrosis after renal transplantation in children with CNS.

    View details for DOI 10.1111/j.1399-3046.2011.01519.x

    View details for Web of Science ID 000306131700011

    View details for PubMedID 21672106

  • Crescentic Glomerulonephritis: An Update on Pauci-immune and Anti-GBM Diseases ADVANCES IN ANATOMIC PATHOLOGY Kambham, N. 2012; 19 (2): 111-124

    Abstract

    Crescentic glomerulonephritis (GN) in a renal biopsy is a widely accepted "critical diagnosis" in Anatomic Pathology practice. Prompt biopsy evaluation and notification of the referring physician is essential to facilitate rapid therapeutic intervention. The differential diagnostic categories of crescentic GN include pauci-immune GN, anti-glomerular basement membrane (GBM) nephritis and immune complex-mediated GN, distinguished from one another by immunofluorescence and electron microscopic study of the renal biopsy. Immune complex-mediated GN is characterized by abundant glomerular deposits and encompasses several diseases including but not limited to lupus nephritis, cryoglobulinemic GN and immunoglobulin A nephropathy. Pauci-immune GN, with paucity of deposits, correlates closely with antineutrophil cytoplasmic antibody disease due to the identifiable circulating pathogenic antineutrophil cytoplasmic antibody in most patients. Recent studies have identified other antibodies in pauci-immune GN and implicated infectious organisms in triggering autoimmunity in a susceptible host by molecular mimicry of host antigens. Anti-GBM nephritis is a rare but potentially life-threatening autoimmune disease with circulating antibodies against GBM epitopes in ?3 chain of type IV collagen. It is characterized by a linear immunoglobulin G deposition along GBM on immunofluorescence microscopy. Environmental triggers including infections and solvent exposure seem to change the tertiary structure of the type IV collagen ?345 hexamer in GBM, expose neoepitopes, and initiate autoimmunity. Even in light of advances in understanding of pathophysiology and serologic testing, renal biopsy remains the mainstay of diagnosis of crescentic GN.

    View details for DOI 10.1097/PAP.0b013e318248b7a1

    View details for Web of Science ID 000300399600005

    View details for PubMedID 22313839

  • CD8(+)CD44(hi) but not CD4(+)CD44(hi) memory T cells mediate potent graft antilymphoma activity without GVHD BLOOD Dutt, S., Baker, J., Kohrt, H. E., Kambham, N., Sanyal, M., Negrin, R. S., Strober, S. 2011; 117 (11): 3230-3239

    Abstract

    Allogeneic hematopoietic cell transplantation can be curative in patients with leukemia and lymphoma. However, progressive growth of malignant cells, relapse after transplantation, and graft-versus-host disease (GVHD) remain important problems. The goal of the current murine study was to select a freshly isolated donor T-cell subset for infusion that separates antilymphoma activity from GVHD, and to determine whether the selected subset could effectively prevent or treat progressive growth of a naturally occurring B-cell lymphoma (BCL(1)) without GVHD after recipients were given T cell-depleted bone marrow transplantations from major histocompatibility complex-mismatched donors. Lethal GVHD was observed when total T cells, naive CD4(+) T cells, or naive CD8(+) T cells were used. Memory CD4(+)CD44(hi) and CD8(+)CD44(hi) T cells containing both central and effector memory cells did not induce lethal GVHD, but only memory CD8(+) T cells had potent antilymphoma activity and promoted complete chimerism. Infusion of CD8(+) memory T cells after transplantation was able to eradicate the BCL(1) lymphoma even after progressive growth without inducing severe GVHD. In conclusion, the memory CD8(+) T-cell subset separated graft antilymphoma activity from GVHD more effectively than naive T cells, memory CD4(+) T cells, or memory total T cells.

    View details for DOI 10.1182/blood-2010-10-312751

    View details for Web of Science ID 000288496300035

    View details for PubMedID 21239702

  • Toll-Like Receptor 4 Contributes to Small Intestine Allograft Rejection TRANSPLANTATION Krams, S. M., Wang, M., Castillo, R. O., Ito, T., Phillips, L., Higgins, J., Kambham, N., Esquivel, C. O., Martinez, O. M. 2010; 90 (12): 1272-1277

    Abstract

    Although outcomes for small intestine transplantation (SIT) have improved in recent years, allograft rejection rates remain among the highest of solid organ grafts. The high load of commensal bacteria in the small intestine may contribute through activation of the toll-like receptor (TLR) pathway. In this study, we examine the participation of TLR4 in acute allograft rejection in an orthotopic mouse model of SIT.Wild-type C57Bl/6 (H-2b) or TLR49(-/-) (H-2b) mice were transplanted with syngeneic (C57Bl/6), allogeneic (BALB/c; H-2d), or F1 (BALB/cxC57Bl/6; H-2d/b) vascularized, orthotopic small intestine grafts. Graft recipients were killed on days 2 to 6 posttransplant. Serum cytokines were measured by Luminex, and tissue was obtained for histology and quantitative real-time polymerase chain reaction.BALB/c grafts transplanted into C57Bl/6 recipients exhibited mixed inflammatory infiltrates, destruction of the mucosa, and significant apoptosis. TLR2 and TLR4 transcripts were modestly increased in syngeneic grafts on days 2 and 6 compared with native bowel, whereas TLR2 and TLR4 were significantly increased on days 2 and 6 in allogeneic grafts. Although fully mismatched and F1 grafts were rejected by C57Bl/6 recipients (mean survival time=8.2 and 9.3 days, respectively), graft survival was significantly prolonged in TLR4(-/-) recipients (mean survival time=10.6 and 14.3 days, respectively). Proinflammatory cytokines were markedly reduced in TLR4(-/-) graft recipients.Small intestine graft survival is prolonged in the absence of TLR4, suggesting that gut flora associated with the graft may augment alloimmune responses through TLR4. Thus, the TLR pathway may be a novel therapeutic target for improving SIT allograft survival.

    View details for DOI 10.1097/TP.0b013e3181fdda0d

    View details for Web of Science ID 000285377100006

    View details for PubMedID 21197709

  • Graft-versus-host disease is enhanced by extracellular ATP activating P2X(7)R NATURE MEDICINE Wilhelm, K., Ganesan, J., Mueller, T., Duerr, C., Grimm, M., Beilhack, A., Krempl, C. D., Sorichter, S., Gerlach, U. V., Juettner, E., Zerweck, A., Gaertner, F., Pellegatti, P., Di Virgilio, F., Ferrari, D., Kambham, N., Fisch, P., Finke, J., Idzko, M., Zeiser, R. 2010; 16 (12): 1434-U117

    Abstract

    Danger signals released upon cell damage can cause excessive immune-mediated tissue destruction such as that found in acute graft-versus-host disease (GVHD), allograft rejection and systemic inflammatory response syndrome. Given that ATP is found in small concentrations in the extracellular space under physiological conditions, and its receptor P2X(7)R is expressed on several immune cell types, ATP could function as a danger signal when released from dying cells. We observed increased ATP concentrations in the peritoneal fluid after total body irradiation, and during the development of GVHD in mice and in humans. Stimulation of antigen-presenting cells (APCs) with ATP led to increased expression of CD80 and CD86 in vitro and in vivo and actuated a cascade of proinflammatory events, including signal transducer and activator of transcription-1 (STAT1) phosphorylation, interferon-γ (IFN-γ) production and donor T cell expansion, whereas regulatory T cell numbers were reduced. P2X(7)R expression increased when GVHD evolved, rendering APCs more responsive to the detrimental effects of ATP, thereby providing positive feedback signals. ATP neutralization, early P2X(7)R blockade or genetic deficiency of P2X(7)R during GVHD development improved survival without immune paralysis. These data have major implications for transplantation medicine, as pharmacological interference with danger signals that act via P2X(7)R could lead to the development of tolerance without the need for intensive immunosuppression.

    View details for DOI 10.1038/nm.2242

    View details for Web of Science ID 000285048900038

    View details for PubMedID 21102458

  • Differentially Expressed RNA from Public Microarray Data Identifies Serum Protein Biomarkers for Cross-Organ Transplant Rejection and Other Conditions PLOS COMPUTATIONAL BIOLOGY Chen, R., Sigdel, T. K., Li, L., Kambham, N., Dudley, J. T., Hsieh, S., Klassen, R. B., Chen, A., Caohuu, T., Morgan, A. A., Valantine, H. A., Khush, K. K., Sarwal, M. M., Butte, A. J. 2010; 6 (9)

    Abstract

    Serum proteins are routinely used to diagnose diseases, but are hard to find due to low sensitivity in screening the serum proteome. Public repositories of microarray data, such as the Gene Expression Omnibus (GEO), contain RNA expression profiles for more than 16,000 biological conditions, covering more than 30% of United States mortality. We hypothesized that genes coding for serum- and urine-detectable proteins, and showing differential expression of RNA in disease-damaged tissues would make ideal diagnostic protein biomarkers for those diseases. We showed that predicted protein biomarkers are significantly enriched for known diagnostic protein biomarkers in 22 diseases, with enrichment significantly higher in diseases for which at least three datasets are available. We then used this strategy to search for new biomarkers indicating acute rejection (AR) across different types of transplanted solid organs. We integrated three biopsy-based microarray studies of AR from pediatric renal, adult renal and adult cardiac transplantation and identified 45 genes upregulated in all three. From this set, we chose 10 proteins for serum ELISA assays in 39 renal transplant patients, and discovered three that were significantly higher in AR. Interestingly, all three proteins were also significantly higher during AR in the 63 cardiac transplant recipients studied. Our best marker, serum PECAM1, identified renal AR with 89% sensitivity and 75% specificity, and also showed increased expression in AR by immunohistochemistry in renal, hepatic and cardiac transplant biopsies. Our results demonstrate that integrating gene expression microarray measurements from disease samples and even publicly-available data sets can be a powerful, fast, and cost-effective strategy for the discovery of new diagnostic serum protein biomarkers.

    View details for DOI 10.1371/journal.pcbi.1000940

    View details for Web of Science ID 000282372600010

    View details for PubMedID 20885780

  • A 30-month-old Child With Acute Renal Failure Due to Primary Renal Cytotoxic T-cell Lymphoma AMERICAN JOURNAL OF SURGICAL PATHOLOGY Paladugu, S., Garro, R., Schrijver, I., Kambham, N., Higgins, J. P. 2010; 34 (7): 1066-1070

    Abstract

    We present a case of a 30-month-old child who presented with anemia and acute renal failure, and was found to have bilateral renal involvement by primary cytotoxic T-cell lymphoma. This was characterized by a monotonous interstitial lymphoid infiltrate with extensive necrosis. The tumor cells showed a CD8, granzyme, and TIA1-positive phenotype with no evidence of Epstein-Barr virus by in situ hybridization. The differential diagnosis based on the biopsy findings included a reactive interstitial nephritis; however, molecular studies confirmed T-cell clonality. She was started on induction chemotherapy and subsequently received maintenance therapy with methotrexate and 6-mercaptopurine. The patient had a complete response after chemotherapy and at 21 months of follow-up, she has no evidence of residual lymphoma; however, she has developed a dilated cardiomyopathy and she remains in renal failure. We discuss the morphologic, immunophenotypic, and molecular features of our case and describe the clinical course of our patient. We review the literature on primary renal lymphoma with an emphasis on T-lineage lymphomas and those that occur in children.

    View details for DOI 10.1097/PAS.0b013e3181de693c

    View details for Web of Science ID 000279167400021

    View details for PubMedID 20495447

  • BK virus nephropathy in the native kidneys of a pediatric heart transplant recipient PEDIATRIC TRANSPLANTATION Sahney, S., Yorgin, P., Zuppan, C., Cutler, D., Kambham, N., Chinnock, R. 2010; 14 (3): E11-E15

    Abstract

    BK virus is a human polyoma virus that may cause nephropathy in immunosuppressed patients. It is a well-recognized cause of renal allograft dysfunction and allograft loss in renal transplant recipients, but it is an infrequent cause of nephropathy outside this setting. There are a few case reports of BK virus nephropathy in the native kidneys of immunosuppressed adult patients with non-renal transplants, but so far it has not been reported in pediatric non-renal solid organ transplant recipients. We report a case of a seven-yr-old heart transplant patient who was diagnosed with BK virus nephropathy, eight months after his second heart transplant. Despite intervention, his renal dysfunction progressed to renal failure. He is currently receiving maintenance hemodialysis and awaiting renal transplantation. It is important to recognize BK virus infection as a possible cause of renal dysfunction in immunosuppressed children who are non-renal transplant recipients.

    View details for DOI 10.1111/j.1399-3046.2008.01122.x

    View details for Web of Science ID 000276495900002

    View details for PubMedID 19175515

  • Compartmental Localization and Clinical Relevance of MICA Antibodies After Renal Transplantation TRANSPLANTATION Li, L., Chen, A., Chaudhuri, A., Kambham, N., Sigdel, T., Chen, R., Sarwal, M. M. 2010; 89 (3): 312-319

    Abstract

    Antibodies (Ab) responses to major and minor human leukocyte antigen loci may impact graft survival after organ transplantation.A ProtoArray platform was used to study 37 serum samples from 15 renal transplant patients with (n=10) and without (n=5) acute rejection (AR) and seven normal controls, and the clinical relevance of major histocompatibility complex class I chain-related gene-A (MICA)-Ab measurements were investigated. Biopsy immunohistochemistry was conducted for localization of the MICA antigen.De novo MICA-Ab were detected in 11 of the 15 transplant patients in this study, irrespective of interval acute graft rejection. Mean MICA-Ab signal intensity was higher in transplant patients with C4d+AR (121.4) versus C4d-AR (4.3), correlated with donor-specific Ab to human leukocyte antigens (r=0.66, P=0.0078), was not elevated in cellular rejections, and correlated with decline in graft function over the subsequent year (r=0.73, P=0.0022). Integrative genomics accurately predicted localization of the MICA antigen to the glomerulus in the normal kidney (Li et al. Proc Natl Acad Sci USA 2009; 106: 4148), because this was confirmed subsequently by immunohistochemistry.Integrative genomics analysis of ProtoArray data is a powerful tool to ascertain de novo antibody responses after renal transplantation and to accurately predict the anatomical location of the target renal antigens. This proof-of-concept study on MICA measurements by ProtoArray demonstrates that antibody responses modulated to MICA after transplantation in patients, irrespective of graft rejection, may be high at the time of humoral rejection and may not be elevated in cellular rejection. Understanding that MICA is preferentially localized to the glomerulus may explain both immunoregulatory and pathogenic roles for MICA after transplantation.

    View details for DOI 10.1097/TP.0b013e3181bbbe4c

    View details for Web of Science ID 000274589200009

    View details for PubMedID 20145522

  • Caspase-4 may play a role in loss of proximal tubules and renal injury in nephropathic cystinosis PEDIATRIC NEPHROLOGY Sansanwal, P., Kambham, N., Sarwal, M. M. 2010; 25 (1): 105-109

    Abstract

    Nephropathic cystinosis is characterized clinically by generalized proximal renal tubular dysfunction, renal Fanconi Syndrome and progressive renal failure. Glomerular-proximal tubule disconnection has been noted in renal biopsies from patients with nephropathic cystinosis. In vitro studies performed in cystinotic fibroblasts and renal proximal tubular cells support a role for apoptosis of the glomerulotubular junction, and we have further extended these studies to human native cystinotic kidney specimens. We performed semi-quantitative analysis of tubular density in kidney biopsies from patients with nephropathic cystinosis and demonstrated a significant reduction (p=0.0003) in the number of proximal tubules in the kidney tissue of patients with cystinosis compared to normal kidneys and kidneys with other causes of renal injury; this reduction appears to be associated with the over-expression of caspase-4. This study provides the first quantitative evidence of a loss of proximal tubules in nephropathic cystinosis and suggests a possible role of caspase-4 in the apoptotic loss of proximal tubular cells. Further work is needed to elucidate if this injury mechanism may be causative for the progression of renal functional decline in nephropathic cystinosis.

    View details for DOI 10.1007/s00467-009-1289-4

    View details for Web of Science ID 000271961000012

    View details for PubMedID 19705160

  • beta-galactosylceramide alters invariant natural killer T cell function and is effective treatment for lupus CLINICAL IMMUNOLOGY Morshed, S. R., Takahashi, T., Savage, P. B., Kambham, N., Strober, S. 2009; 132 (3): 321-333

    Abstract

    NZB/W female mice spontaneously develop systemic lupus, an autoantibody mediated disease associated with immune complex glomerulonephritis. Natural killer (NK) T cells augment anti-dsDNA antibody secretion by NZB/W B cells in vitro, and blocking NKT cell activation in vivo with anti-CD1 mAb ameliorates lupus disease activity. In the current study, we show that beta-galactosylceramide reduces the in vivo induction of serum IFN-gamma and/or IL-4 by the potent NKT cell agonist alpha-galactosylceramide and reduces NKT cell helper activity for IgG secretion. Treatment of NZB/W mice with the beta-galactosylceramide ameliorated lupus disease activity as judged by improvement in proteinuria, renal histopathology, IgG anti-dsDNA antibody formation, and survival. In conclusion, beta-galactosylceramide, a glycolipid that reduces the cytokine secretion induced by a potent NKT cell agonist ameliorates lupus in NZB/W mice.

    View details for DOI 10.1016/j.clim.2009.05.018

    View details for Web of Science ID 000268783900004

    View details for PubMedID 19564135

  • Crescentic Glomerulonephritis With Ribbon-like Immunofluorescence Pattern AMERICAN JOURNAL OF KIDNEY DISEASES Chirunomula, V., Kondle, V., Vaddey, B., Colvin, R. B., Kambham, N. 2009; 54 (2): 381-384

    View details for DOI 10.1053/j.ajkd.2008.11.011

    View details for Web of Science ID 000269640200024

    View details for PubMedID 19121555

  • Expression of Complement Components Differs Between Kidney Allografts from Living and Deceased Donors JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY Naesens, M., Li, L., Ying, L., Sansanwal, P., Sigdel, T. K., Hsieh, S., Kambham, N., Lerut, E., Salvatierra, O., Butte, A. J., Sarwal, M. M. 2009; 20 (8): 1839-1851

    Abstract

    A disparity remains between graft survival of renal allografts from deceased donors and from living donors. A better understanding of the molecular mechanisms that underlie this disparity may allow the development of targeted therapies to enhance graft survival. Here, we used microarrays to examine whole genome expression profiles using tissue from 53 human renal allograft protocol biopsies obtained both at implantation and after transplantation. The gene expression profiles of living-donor kidneys and pristine deceased-donor kidneys (normal histology, young age) were significantly different before reperfusion at implantation. Deceased-donor kidneys exhibited a significant increase in renal expression of complement genes; posttransplantation biopsies from well-functioning, nonrejecting kidneys, regardless of donor source, also demonstrated a significant increase in complement expression. Peritransplantation phenomena, such as donor death and possibly cold ischemia time, contributed to differences in complement pathway gene expression. In addition, complement gene expression at the time of implantation was associated with both early and late graft function. These data suggest that complement-modulating therapy may improve graft outcomes in renal transplantation.

    View details for DOI 10.1681/ASN.2008111145

    View details for Web of Science ID 000268903200028

    View details for PubMedID 19443638

  • Steroid-Free Immunosuppression Since 1999: 129 Pediatric Renal Transplants with Sustained Graft and Patient Benefits AMERICAN JOURNAL OF TRANSPLANTATION Li, L., Chang, A., Naesens, M., Kambham, N., Waskerwitz, J., Martin, J., Wong, C., Alexander, S., Grimm, P., Concepcion, W., Salvatierra, O., Sarwal, M. M. 2009; 9 (6): 1362-1372

    Abstract

    Despite early promising patient and graft outcomes with steroid-free (SF) immunosuppression in pediatric kidney transplant recipients, data on long-term safety and efficacy results are lacking. We present our single-center experience with 129 consecutive pediatric kidney transplant recipients on SF immunosuppression, with a mean follow-up of 5 years. Outcomes are compared against a matched cohort of 57 concurrent recipients treated with steroid-based (SB) immunosuppression. In the SF group, 87% of kidney recipients with functioning grafts remain corticosteroid-free. Actual intent-to-treat SF (ITT-SF) and still-on-protocol SF patient survivals are 96% and 96%, respectively, actual graft survivals for both groups are 93% and 96%, respectively and actual death-censored graft survivals for both groups are 97% and 99%, respectively. Unprecedented catch-up growth is observed in SF recipients below 12 years of age. Continued low rates of acute rejection, posttransplant diabetes mellitus (PTDM), hypertension and hyperlipidemia are seen in SF patients, with sustained benefits for graft function. In conclusion, extended enrollment and longer experience with SF immunosuppression for renal transplantation in low-risk children confirms protocol safety, continued benefits for growth and graft function, low acute rejection rates and reduced cardiovascular morbidity.

    View details for DOI 10.1111/j.1600-6143.2009.02640.x

    View details for Web of Science ID 000266448900017

    View details for PubMedID 19459814

  • Identifying compartment-specific non-HLA targets after renal transplantation by integrating transcriptome and "antibodyome'' measures PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Li, L., Wadia, P., Chen, R., Kambham, N., Naesens, M., Sigdel, T. K., Miklos, D. B., Sarwal, M. M., Butte, A. J. 2009; 106 (11): 4148-4153

    Abstract

    We have conducted an integrative genomics analysis of serological responses to non-HLA targets after renal transplantation, with the aim of identifying the tissue specificity and types of immunogenic non-HLA antigenic targets after transplantation. Posttransplant antibody responses were measured by paired comparative analysis of pretransplant and posttransplant serum samples from 18 pediatric renal transplant recipients, measured against 5,056 unique protein targets on the ProtoArray platform. The specificity of antibody responses were measured against gene expression levels specific to the kidney, and 2 other randomly selected organs (heart and pancreas), by integrated genomics, employing the mapping of transcription and ProtoArray platform measures, using AILUN. The likelihood of posttransplant non-HLA targets being recognized preferentially in any of 7 microdissected kidney compartments was also examined. In addition to HLA targets, non-HLA immune responses, including anti-MICA antibodies, were detected against kidney compartment-specific antigens, with highest posttransplant recognition for renal pelvis and cortex specific antigens. The compartment specificity of selected antibodies was confirmed by IHC. In conclusion, this study provides an immunogenic and anatomic roadmap of the most likely non-HLA antigens that can generate serological responses after renal transplantation. Correlation of the most significant non-HLA antibody responses with transplant health and dysfunction are currently underway.

    View details for DOI 10.1073/pnas.0900563106

    View details for Web of Science ID 000264278800020

    View details for PubMedID 19251643

  • X box-binding protein 1 regulates angiogenesis in human pancreatic adenocarcinomas. Translational oncology Romero-Ramirez, L., Cao, H., Regalado, M. P., Kambham, N., Siemann, D., Kim, J. J., Le, Q. T., Koong, A. C. 2009; 2 (1): 31-38

    Abstract

    Tumors encounter endoplasmic reticulum stress during tumor growth and activate an adaptive pathway known as the unfolded protein response (UPR). Because this pathway is induced by the tumor microenvironment, it is a promising target for cancer therapy. We have previously demonstrated that X-box binding protein 1 (XBP-1), a key regulator of the UPR, was required for survival under hypoxia and critical for tumor growth in tumor xenografts. In this study, we investigated the role of XBP-1 in regulating tumor angiogenesis.We used an intradermal angiogenesis model to quantify the effect of XBP-1 on angiogenesis. We also used a human tumor xenograft model to assay for tumor growth delay. We determined vascular endothelial growth factor (VEGF) expression by quantitative polymerase chain reaction and ELISA. Finally, we stained human pancreatic adenocarcinoma specimens for XBP-1 expression and correlated the expression pattern of XBP-1 with CD31 (endothelial cell marker) expression.We demonstrated that XBP-1 is essential for angiogenesis during early tumor growth. Inhibiting XBP-1 expression by short-hairpin RNA sequence specific for XBP-1 reduced blood vessel formation in tumors from mouse embryonic fibroblast cells and human fibrosarcoma tumor cells (HT1080). Expressing a dominant-negative form of IRE1alpha also reduced blood vessel formation in tumors. Moreover, expression of spliced XBP-1 (XBP-1s) restored angiogenesis in IRE1alpha dominant-negative expressing cells. We further demonstrated that XBP-1-mediated angiogenesis does not depend on VEGF.We propose that the IRE1alpha-XBP-1 branch of the UPR modulates a complex proangiogenic, VEGF-independent response that depends on signals received from the tumor microenvironment.

    View details for PubMedID 19252749

  • XBP-1 regulates angiogenesis in human pancreatic adenocarcinomas TRANSLATIONAL ONCOLOGY Romero-Ramirez, L., Cao, H., Regalado, M. P., Kambham, N., Siemann, D., Kim, J. J., Le, Q. T., Koong, A. C. 2009; 2 (1): 31-U42

    View details for DOI 10.1593/tlo.08211

    View details for Web of Science ID 000272550900004

  • The Role of Tumor Cell-Derived Connective Tissue Growth Factor (CTGF/CCN2) in Pancreatic Tumor Growth CANCER RESEARCH Bennewith, K. L., Huang, X., Ham, C. M., Graves, E. E., Erler, J. T., Kambham, N., Feazell, J., Yang, G. P., Koong, A., Giaccia, A. J. 2009; 69 (3): 775-784

    Abstract

    Pancreatic cancer is highly aggressive and refractory to existing therapies. Connective tissue growth factor (CTGF/CCN2) is a fibrosis-related gene that is thought to play a role in pancreatic tumor progression. However, CCN2 can be expressed in a variety of cell types, and the contribution of CCN2 derived from either tumor cells or stromal cells as it affects the growth of pancreatic tumors is unknown. Using genetic inhibition of CCN2, we have discovered that CCN2 derived from tumor cells is a critical regulator of pancreatic tumor growth. Pancreatic tumor cells derived from CCN2 shRNA-expressing clones showed dramatically reduced growth in soft agar and when implanted s.c. We also observed a role for CCN2 in the growth of pancreatic tumors implanted orthotopically, with tumor volume measurements obtained by positron emission tomography imaging. Mechanistically, CCN2 protects cells from hypoxia-mediated apoptosis, providing an in vivo selection for tumor cells that express high levels of CCN2. We found that CCN2 expression and secretion was increased in hypoxic pancreatic tumor cells in vitro, and we observed colocalization of CCN2 and hypoxia in pancreatic tumor xenografts and clinical pancreatic adenocarcinomas. Furthermore, we found increased CCN2 staining in clinical pancreatic tumor tissue relative to stromal cells surrounding the tumor, supporting our assertion that tumor cell-derived CCN2 is important for pancreatic tumor growth. Taken together, these data improve our understanding of the mechanisms responsible for pancreatic tumor growth and progression, and also indicate that CCN2 produced by tumor cells represents a viable therapeutic target for the treatment of pancreatic cancer.

    View details for DOI 10.1158/0008-5472.CAN-08-0987

    View details for Web of Science ID 000263048700010

    View details for PubMedID 19179545

  • Decreases in circulating CD4(+)CD25(hi)FOXP3(+) cells and increases in intragraft FOXP3(+) cells accompany allograft rejection in pediatric liver allograft recipients PEDIATRIC TRANSPLANTATION Stenard, F., Nguyen, C., Cox, K., Kambham, N., Umetsu, D. T., Krams, S. M., Esquivel, C. O., Martinez, O. M. 2009; 13 (1): 70-80

    Abstract

    We examined CD4(+)CD25(hi)FOXP3(+) cells Treg in children following liver transplantation and determined the relationship between Treg cell levels in the blood and in the graft. Peripheral blood was obtained from pediatric liver transplant patients at sequential time points: pre-transplant, one month, 3-4 months, 6-7 months, and 11-12 months post-transplant. PBMC were isolated, labeled for CD4, CD25 and FOXP3 expression and analyzed by flow cytometry for CD4(+)CD25(hi)FOXP3(+) cells. Sorted CD4(+)CD25(hi) cells were assessed for functional activity. Pretransplant blood levels of CD4(+)CD25(hi)FOXP3(+) Treg cells were not significantly different from post-transplant blood levels of CD4(+)CD25(hi)FOXP3(+) Treg cells. However, the blood levels of CD4(+)CD25(hi)FOXP3(+) Treg cells were significantly decreased during acute rejection compared with levels when graft function was stable. Immunohistochemistry revealed that FOXP3(+) cells were increased in the portal region of livers with histopathologic evidence of acute graft rejection compared with livers without evidence of rejection and were localized primarily within the inflammatory infiltrate. These data indicate that Treg cells are found at the site of allograft rejection and may play a role in regulation of alloreactivity. Moreover, monitoring peripheral CD4(+)CD25(hi)FOXP3(+) Treg cell levels may be useful in improving the post-transplant management of pediatric liver allograft recipients.

    View details for DOI 10.1111/j.1399-3046.2008.00917.x

    View details for Web of Science ID 000262285400012

    View details for PubMedID 18331536

  • Choroidopathy and kidney disease: a case report and review of the literature. Cases journal Kamdar, N. V., Erko, A., Ehrlich, J. S., Kim, J. W., Kambham, N., Chertow, G. M. 2009; 2: 7425-?

    Abstract

    The patient was a 41 year-old Mexican American women who presented with a decrease in visual acuity along with periorbital and peripheral edema. She was diagnosed with bilateral serous retinal detachment and diffuse proliferative lupus nephritis. She improved considerably in hospital after treatment with corticosteroids.

    View details for DOI 10.1186/1757-1626-2-7425

    View details for PubMedID 19829960

  • A Randomized, Prospective Trial of Rituximab for Acute Rejection in Pediatric Renal Transplantation AMERICAN JOURNAL OF TRANSPLANTATION Zarkhin, V., Li, L., Kambham, N., Sigdel, T., Salvatierra, O., Sarwal, M. M. 2008; 8 (12): 2607-2617

    Abstract

    We report 1-year outcomes of a randomized study of Rituximab versus standard-of-care immunosuppression (Thymoglobulin and/or pulse steroids) for treatment of biopsy confirmed, acute transplant rejection with B-cell infiltrates, in 20 consecutive recipients (2-23 years). Graft biopsies, with Banff and CADI scores, CD20 and C4d stains, were performed at rejection and 1 and 6 months later. Peripheral blood CMV, EBV and BK viral loads, graft function, DSA, immunoglobulins, serum humanized antichimeric antibody (HACA) and Rituximab, and lymphocyte counts were monitored until 1 year posttreatment. Rituximab infusions were given with a high index of safety without HACA development and increased infections complications. Rituximab therapy resulted in complete tissue B-cell depletion and rapid peripheral B-cell depletion. Peripheral CD19 cells recovered at a mean time of approximately 12 months. There were some benefits for the recovery of graft function (p = 0.026) and improvement of biopsy rejection scores at both the 1- (p = 0.0003) and 6-month (p < 0.0001) follow-up biopsies. Reappearance of C4d deposition was not seen on follow-up biopsies after Rituximab therapy, but was seen in 30% of control patients. There was no change in DSA in either group, independent of rejection resolution. This study reports safety and suggests further investigation of Rituximab as an adjunctive treatment for B-cell-mediated graft rejection.

    View details for DOI 10.1111/j.1600-6143.2008.02411.x

    View details for Web of Science ID 000261053600021

    View details for PubMedID 18808404

  • Characterization of intra-graft B cells during renal allograft rejection KIDNEY INTERNATIONAL Zarkhin, V., Kambham, N., Li, L., Kwok, S., Hsieh, S., Salvatierra, O., Sarwal, M. M. 2008; 74 (5): 664-673

    Abstract

    Intra-graft CD20(+) B-cell clusters are found during acute rejection of renal allografts and correlate with graft recovery following rejection injury. Here using archived kidney tissue we conducted immunohistochemical studies to measure specific subsets of pathogenic B cells during graft rejection. Cluster-forming CD20(+) B cells in the rejected graft are likely derived from the recipient and are composed of mature B cells. These cells are activated (CD79a(+)), and present MHC Class II antigen (HLADR(+)) to CD4(+) T cells. Some of these clusters contained memory B cells (CD27(+)) and they did not correlate with intra-graft C4d deposition or with detection of donor-specific antibody. Further, several non-cluster forming CD20(-) B-lineage CD38(+) plasmablasts and plasma cells were found to infiltrate the rejected grafts and these cells strongly correlated with circulating donor-specific antibody, and to a lesser extent with intra-graft C4d. Both CD20(+) B cells and CD38(+) cells correlated with poor response of the rejection to steroids. Reduced graft survival was associated with the presence of CD20 cells in the graft. In conclusion, a specific subset of early lineage B cells appears to be an antigen-presenting cell and which when present in the rejected graft may support a steroid-resistant T-cell-mediated cellular rejection. Late lineage interstitial plasmablasts and plasma cells may also support humoral rejection. These studies suggest that detailed analysis of interstitial cellular infiltrates may allow better use of B-cell lineage specific treatments to improve graft outcomes.

    View details for DOI 10.1038/ki.2008.249

    View details for Web of Science ID 000258531800019

    View details for PubMedID 18547992

  • Patient selection critical for calcineurin inhibitor withdrawal in pediatric kidney transplantation PEDIATRIC TRANSPLANTATION Weintraub, L., Li, L., Kambham, N., Alexander, S., Concepcion, W., Miller, K., Wong, C., Salvatierra, O., Sarwal, M. 2008; 12 (5): 541-549

    Abstract

    CNI withdrawal may be employed as a "rescue" strategy for patients with established renal allograft injury and/or declining allograft function, with the aim at eliminating CNI-associated nephrotoxic effects. This analysis reviews outcomes in a pediatric population and identifies risk factors for adverse events post-CNI withdrawal. We performed a retrospective analysis of 17 pediatric renal transplants who underwent CNI withdrawal, with conversion to sirolimus and MMF. Mean CrCl decreased from 64.3 +/- 22 to 59.38 +/- 28.6 mL/min/1.73 m(2) (p = 0.04) at six months and 57.46 +/- 31.1 mL/min/1.73 m(2) (p = 0.02) at 12 months post-withdrawal. Forty-one percent of patients experienced AR. Increased risk for AR was associated with prior AR history, lower sirolimus trough levels, and lower CNIT biopsy scores. Graft loss (24%) was associated with worse CrCl, proteinuria, and histologic chronicity. Proteinuria (spot protein/creatinine ratio) increased from 0.75 +/- 1.0 to 1.71 +/- 2.0 (p = 0.03), unrelated to de novo sirolimus use. Four patients returned to CNI-based immunosuppression due to AR (n = 3) and gastrointestinal side effects (n = 1). Careful selection of pediatric candidates for CNI withdrawal is recommended. Worsening graft function and graft loss may be minimized by selecting patients with high CNIT scores and low biopsy chronicity and excluding patients with prior AR history.

    View details for DOI 10.1111/j.1399-3046.2007.00847.x

    View details for Web of Science ID 000257700900013

    View details for PubMedID 18564305

  • H-Y antibody development associates with acute rejection in female patients with male kidney transplants TRANSPLANTATION Tan, J. C., Wadia, P. P., Coram, M., Grumet, F. C., Kambham, N., Miller, K., Pereira, S., Vayntrub, T., Miklos, D. B. 2008; 86 (1): 75-81

    Abstract

    Human minor histocompatibility antigens (mHA) and clinically relevant immune responses to them have not been well defined in organ transplantation. We hypothesized that women with male kidney transplants would develop antibodies against H-Y, the mHA encoded on the Y-chromosome, in association with graft rejection.We tested sera from 118 consecutive transplant recipients with kidney biopsies. Antibodies that specifically recognized the recombinant H-Y antigens RPS4Y1 or DDX3Y were detected by IgG enzyme-linked immunosorbent assay and western blotting. Immunogenic epitopes were further identified using overlapping H-Y antigen peptides for both the H-Y proteins.In the 26 female recipients of male kidneys, H-Y antibody development posttransplant (1) was more frequent (46%) than in other gender combinations (P<0.001), (2) showed strong correlation with acute rejection (P=0.00048), (3) correlated with plasma cell infiltrates in biopsied kidneys (P=0.04), and (4) did not correlate with C4d deposition or donor-specific anti-human leukocyte antigen (HLA) antibodies. Of the two H-Y antigens, RPS4Y1 was more frequently recognized (P=0.005).This first demonstration of a strong association between H-Y antibody development and acute rejection in kidney transplant recipients shows that in solid organ allografts, humoral immune responses against well defined mHA have clear clinical correlates, can be easily monitored, and warrant study for possible effects on long-term graft function.

    View details for DOI 10.1097/TP.0b013e31817352b9

    View details for Web of Science ID 000257790400014

    View details for PubMedID 18622281

  • Maturation of dose-corrected tacrolimus predose trough levels in pediatric kidney allograft recipients TRANSPLANTATION Naesens, M., Salvatierra, O., Li, L., Kambham, N., Concepcion, W., Sarwal, M. 2008; 85 (8): 1139-1145

    Abstract

    In contrast to adult kidney recipients, in whom the long-term evolution and clinical determinants of tacrolimus pharmacokinetics are well studied, less is known about the long-term evolution of tacrolimus pharmacokinetics in pediatric kidney transplant recipients.One-hundred and five pediatric recipients of a kidney allograft, all treated with a corticosteroid-free immunosuppressive protocol, were included. The evolution of tacrolimus doses and predose trough (C0) levels was recorded at 3, 6, 9, 12, 18, and 24 months after transplantation, as well as all C0 levels obtained in the first 2 years after transplantation. The evolution and clinical determinants of tacrolimus exposure parameters were analyzed.Dose-corrected tacrolimus C0 levels (C0/dose/kg) increased in the first 2 years after kidney transplantation in pediatric recipients (P=0.001). This decrease in dose requirement by time was only significant in children older than 5 years at the time of transplantation (P=0.38, 0.03, and 0.001 for age groups <5, 5-12, and >12 years, respectively). In addition, the younger patients had significantly higher dose requirements (dose/kg) compared with older recipients (P=0.0002).Pediatric kidney transplant recipients exhibit maturation of dose-corrected tacrolimus predose trough levels with time after transplantation. This cannot be explained by differences in corticosteroid use, because all patients were treated with a corticosteroid-free protocol. The higher dose requirements for younger recipients and the absence of tacrolimus maturation in the youngest recipients suggest that age-dependent changes in tacrolimus intestinal first-pass effect, metabolism, or distribution play a role. Whether age-specific tacrolimus dosing algorithms will improve outcome needs further study.

    View details for DOI 10.1097/TP.001361816431a

    View details for Web of Science ID 000255318200014

    View details for PubMedID 18431234

  • Renal pathology in hematopoietic cell transplantation recipients MODERN PATHOLOGY Troxell, M. L., Pilapil, M., Miklos, D. B., Higgins, J. P., Kambham, N. 2008; 21 (4): 396-406

    Abstract

    Hematopoietic cell transplantation-associated renal injury may be related to a combination of factors including chemotherapy, radiation, infection, immunosuppressive agents, ischemia, and graft-versus-host disease. Renal biopsy specimens from hematopoietic cell transplant recipients at two institutions (Stanford University Medical Center and Oregon Health & Science University) were reviewed in correlation with clinical data. Fifteen cases were identified (post hematopoietic cell transplant time 0.7-14.5 years), including six with autologous hematopoietic cell transplant. Indications for renal biopsy included proteinuria (n=13; nephrotic range in 8), increased serum creatinine (n=10), or both (n=6). Many patients had multiple pathologic findings on renal biopsy. Membranous glomerulonephritis was the most common diagnosis (n=7), including two patients with autologous hematopoietic cell transplant and five with evidence of chronic graft-versus-host disease elsewhere. Four membranous glomerulonephritis patients achieved sustained remission with rituximab therapy. Other glomerular pathology included focal segmental glomerulosclerosis (n=1) and minimal change disease (n=1). Evidence of thrombotic microangiopathy was common (in isolation or combined with other pathology), as was acute tubular necrosis and tubulointerstitial nephritis. Of 14 patients with follow-up (2-64 months, mean 19 months), 6 had chronic renal insufficiency (serum creatinine >1.5 mg/dl), 2 had end stage renal disease, and 6 had essentially normal renal function. Our retrospective study shows that renal dysfunction in hematopoietic cell transplant recipients is often multifactorial, and biopsy may reveal treatable causes. Membranous glomerulonephritis is seen in autologous and allogeneic hematopoietic cell transplant recipients, and may respond to anti-B-cell therapy, which has implications regarding pathogenesis and relationship to graft-versus-host disease.

    View details for DOI 10.1038/modpathol.3801011

    View details for Web of Science ID 000254288500005

    View details for PubMedID 18223556

  • The impact of regulatory T cells on T-cell immunity following hematopoietic cell transplantation BLOOD Nguyen, V. H., Shashidhar, S., Chang, D. S., Ho, L., Kambham, N., Bachmann, M., Brown, J. M., Negrin, R. S. 2008; 111 (2): 945-953

    Abstract

    Regulatory T cells (Tregs) prevent graft-versus-host disease (GvHD) by inhibiting the proliferation and function of conventional T cells (Tcons). However, the impact of Tregs on T-cell development and immunity following hematopoietic cell transplantation (HCT) is unknown. Using a murine GvHD model induced by Tcons, we demonstrate that adoptive transfer of Tregs leads to (1) abrogration of GvHD, (2) preservation of thymic and peripheral lymph node architecture, and (3) an accelerated donor lymphoid reconstitution of a diverse TCR-Vbeta repertoire. The resultant enhanced lymphoid reconstitution in Treg recipients protects them from lethal cytomegalovirus (MCMV) infection. By contrast, mice that receive Tcons alone have disrupted lymphoid organs from GvHD and remain lymphopenic with a restricted TCR-Vbeta repertoire and rapid death on MCMV challenge. Lymphocytes from previously infected Treg recipients generate secondary response specific to MCMV, indicating long-term protective immunity with transferred Tregs. Thymectomy significantly reduces survival after MCMV challenge in Treg recipients compared with euthymic controls. Our results indicate that Tregs enhance immune reconstitution by preventing GvHD-induced damage of the thymic and secondary lymphoid microenvironment. These findings provide new insights into the role of Tregs in affording protection to lymphoid stromal elements important for T-cell immunity.

    View details for DOI 10.1182/blood-2007-07-103895

    View details for Web of Science ID 000252458700071

    View details for PubMedID 17916743

  • Differential impact of mammalian target of rapamycin inhibition on CD4(+)CD25(+)Foxp3(+) regulatory T cells compared with conventional CD4(+) T cells BLOOD Zeiser, R., Leveson-Gower, D. B., Zambricki, E. A., Kambham, N., Beilhack, A., Loh, J., Hou, J., Negrin, R. S. 2008; 111 (1): 453-462

    Abstract

    Based on their ability to control T-cell homeostasis, Foxp3(+)CD4(+)CD25(+) regulatory T cells (Tregs) are being considered for treatment of autoimmune disorders and acute graft-versus-host disease (aGVHD). When combining Tregs with the immunosuppressant rapamycin (RAPA), we observed reduced alloreactive conventional T-cell (Tconv) expansion and aGVHD lethality compared with each treatment alone. This synergistic in vivo protection was paralleled by intact expansion of polyclonal Tregs with conserved high FoxP3 expression. In contrast to Tconv, activation of Tregs with alloantigen and interleukin-2 preferentially led to signal transducer and activator of transcription 5 (STAT5) phosphorylation and not phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway activity. Expression of phosphatase and tensin homolog deleted on chromosome 10 (PTEN), a negative regulator of the PI3K/Akt/mTOR pathway, remained high in Tregs but not Tconv during stimulation. Conversely, targeted deletion of PTEN increased susceptibility of Tregs to mTOR inhibition by RAPA. Differential impact of RAPA as a result of reduced usage of the mTOR pathway in Tregs compared with conventional T cells explains the synergistic effect of RAPA and Tregs in aGVHD protection, which has important implications for clinical trials using Tregs.

    View details for DOI 10.1182/blood-2007-06-094482

    View details for Web of Science ID 000252002000063

    View details for PubMedID 17967941

  • Preemptive HMG-CoA reductase inhibition provides graft-versus-host disease protection by Th-2 polarization while sparing graft-versus-leukemia activity BLOOD Zeiser, R., Youssef, S., Baker, J., Kambham, N., Steinman, L., Negrin, R. S. 2007; 110 (13): 4588-4598

    Abstract

    We investigated whether atorvastatin (AT) was capable of protecting animals from acute graft-versus-host disease (aGVHD) across major histocompatibility complex (MHC) mismatch barriers. AT treatment of the donor induced a Th-2 cytokine profile in the adoptively transferred T cells and reduced their in vivo expansion, which translated into significantly reduced aGVHD lethality. Host treatment down-regulated costimulatory molecules and MHC class II expression on recipient antigen-presenting cells (APCs) and enhanced the protective statin effect, without impacting graft-versus-leukemia (GVL) activity. The AT effect was partially reversed in STAT6(-/-) donors and abrogated by L-mevalonate, indicating the relevance of STAT6 signaling and the L-mevalonate pathway for AT-mediated aGVHD protection. AT reduced prenylation levels of GTPases, abolished T-bet expression, and increased c-MAF and GATA-3 protein in vivo. Thus, AT has significant protective impact on aGVHD lethality by Th-2 polarization and inhibition of an uncontrolled Th-1 response while maintaining GVL activity, which is of great clinical relevance given the modest toxicity profile of AT.

    View details for DOI 10.1182/blood-2007-08-106005

    View details for Web of Science ID 000252001200068

    View details for PubMedID 17827390

  • Host-derived interleukin-18 differentially impacts regulatory and conventional T cell expansion during acute graft-versus-host disease BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION Zeiser, R., Zambricki, E. A., Leveson-Gower, D., Kambham, N., Beilhack, A., Negrin, R. S. 2007; 13 (12): 1427-1438

    Abstract

    Interleukin (IL)-18 stimulates T helper 1 (Th1) and Th2-mediated immune responses, and has been shown to modulate acute graft-versus-host disease (aGVHD). It is still unknown whether increased IL-18 levels during aGVHD are of host or donor origin, and how the absence of IL-18 has an impact on migration and expansion of conventional CD4(+)CD25(-)(Tconv) and CD4(+)CD25(+) regulatory (Treg) T cells in vivo. By utilizing IL-18 gene-deficient donor versus recipient animals we found that the major cytokine production during the early phase of aGVHD induction was recipient derived, whereas donor hematopoietic cells contributed significantly less. By generating IL-18(-/-) luciferase transgenic mice we were able to investigate the impact of IL-18 on Tconv and Treg expansion and trafficking with in vivo bioluminescence imaging. Although migration to secondary lymphoid organs did not have a significantly impact from the absence of host IL-18, Tconv but not Treg expansion increased significantly. Absence of host IL-18 production translated into lower IFN-gamma levels in the early phase after transplantation. We conclude that host-derived IL-18 is a major factor for IFN-gamma production that may have a protective effect on CD4(+)-mediated aGVHD, but is nonessential for Treg expansion in an allogeneic environment.

    View details for DOI 10.1016/j.bbmt.2007.08.041

    View details for Web of Science ID 000251495900004

    View details for PubMedID 18022572

  • The evolution of nonimmune histological injury and its clinical relevance in adult-sized kidney grafts in pediatric recipients AMERICAN JOURNAL OF TRANSPLANTATION Naesens, M., Kambham, N., Concepcion, W., Salvatierra, O., Sarwal, M. 2007; 7 (11): 2504-2514

    Abstract

    To describe the evolution, risk factors and impact of nonimmune histological injury after pediatric kidney transplantation, we analyzed 245 renal allograft protocol biopsies taken regularly from the time of transplantation to 2 years thereafter in 81 consecutive rejection-free pediatric recipients of an adult-sized kidney. Isometric tubular vacuolization was present early after transplantation was not progressive, and was associated with higher tacrolimus pre-dose trough levels. Chronic tubulo-interstitial damage and tubular microcalcifications were already noted at 3 months, were progressive and had a greater association with small recipient size, male donor gender, higher donor age and female recipient gender, but not with tacrolimus exposure. Renal function assessment showed that older recipients had a significant increase in absolute glomerular filtration rate with time after transplantation, which differed from small recipients who showed no increase. It is concluded that progressive, functionally relevant, nonimmune injury is detected early after adult-sized kidney transplantation in pediatric recipients. Renal graft ischemia associated with the donor-recipient size discrepancy appears to be a greater risk factor for this chronic histological injury, suggesting that the exploration of additional therapeutic approaches to increase allograft perfusion could further extend the graft survival benefit of adult-sized kidneys transplanted into small children.

    View details for DOI 10.1111/j.1600-6143.2007.01949.x

    View details for Web of Science ID 000250077600010

    View details for PubMedID 17725681

  • Liver allografts are toleragenic in rats conditioned with posttransplant total lymphoid irradiation TRANSPLANTATION Nagasaki, K., Obara, H., Xiong, A., Kambham, N., Strober, S., Esquivel, C. O., Millan, M. T. 2007; 84 (5): 619-628

    Abstract

    Posttransplant total lymphoid irradiation (TLI) treatment has been applied to tolerance induction protocols in heart and kidney transplantation models.We examined the efficacy and mechanism of posttransplant TLI treatment in the induction and maintenance of tolerance in a rat orthotopic liver transplantation model.Posttransplant TLI prolonged ACI (RT1(a)) liver allograft survival in Lewis (RT1(b)) hosts, with 50% long-term engraftment without immunosuppression and without evidence of chronic rejection. Injection of donor-type liver mononuclear cells (LMCs) facilitated the prolongation of graft survival, with more than 70% of grafts in LMC recipients surviving more than 100 days without chronic rejection. Recipients with long-term liver allograft survival accepted ACI but not PVG skin grafts. In TLI-conditioned recipients with accepted grafts, apoptosis occurred predominantly in graft-infiltrating leukocytes. In contrast, there were few apoptotic leukocytes in rejecting grafts. Recipients with long-term graft acceptance (>100 days of survival) demonstrated evidence of immune deviation; mixed lymphocyte reaction to ACI stimulator cells was vigorous, but secretion of interferon-gamma and interleukin-2 was reduced. In tolerant recipients, the number of Foxp3(+) CD25(+) CD4(+) regulatory T cells was increased in the liver allograft as well as in the peripheral blood.We conclude that posttransplant TLI induces tolerance to liver allografts via a mechanism involving apoptotic cell-deletion and immunoregulation.

    View details for DOI 10.1097/01.tp.0000278104.15002.64

    View details for Web of Science ID 000249574900009

    View details for PubMedID 17876275

  • CD101 surface expression discriminates potency among murine FoxP3(+) regulatory T cells JOURNAL OF IMMUNOLOGY Fernandez, I., Zeiser, R., Karsunky, H., Kambham, N., Beilhack, A., Soderstrom, K., Negrin, R. S., Engleman, E. 2007; 179 (5): 2808-2814

    Abstract

    CD4+CD25+FoxP3+ regulatory T cells (Treg) have been shown to be protective in animal models of autoimmunity and acute graft-vs-host disease. However, owing to the functional heterogeneity among CD4+CD25+ T cells, surface markers expressed selectively on functionally active Treg would be useful for purposes of identifying and isolating such cells. We generated a rabbit mAb against murine CD101, a transmembrane glycoprotein involved in T cell activation. Among freshly isolated T cells, CD101 was detected on 25-30% of CD4+CD25+ Treg and approximately 20% of conventional memory T cells. CD101(high) Treg displayed greater in vitro suppression of alloantigen-driven T cell proliferation as compared with CD101(low) Treg. In a model of graft-vs-host disease induced by allogeneic bone marrow transplantation in vivo bioluminescence imaging demonstrated reduced expansion of donor-derived luciferase-labeled conventional T cells in mice treated with CD101(high) Treg, compared with CD101(low) Treg. Moreover, treatment with CD101(high) Treg resulted in improved survival, reduced proinflammatory cytokine levels and reduced end organ damage. Among the CD101(high) Treg all of the in vivo suppressor activity was contained within the CD62L(high) subpopulation. We conclude that CD101 expression distinguishes murine Treg with potent suppressor activity.

    View details for Web of Science ID 000248991800020

    View details for PubMedID 17709494

  • A novel bioluminescent tumor model of human renal cancer cell lines: An in vitro and in vivo characterization JOURNAL OF UROLOGY Peter, C., Kielstein, J. T., Clarke-Katzenberg, R., Adams, M. C., Pitsiouni, M., Kambham, N., Karimi, M. A., Kengatharan, K. M., Cooke, J. P. 2007; 177 (6): 2342-2346

    Abstract

    Bioluminescent imaging permits sensitive in vivo detection and quantification of cells engineered to emit light. We developed a bioluminescent human renal cancer cell line for in vitro and in vivo studies.The 2 human renal cell carcinoma cell lines SN12-C and SN12-L1 were stably transfected to constitutively express luciferase using a retroviral shuttle. The bioluminescent signal was correlated with tumor cell numbers in vitro. Parental and transfected cells were compared by growth kinetics and histology. Tumor burden after heterotopic injection in immune deficient mice was monitored up to 39 days. The kinetics of the bioluminescent signal was evaluated for 1 to 60 minutes following luciferin injection.Bioengineered renal cancer cell lines stably expressed luciferase. The growth kinetics of the cells in vitro and the histology of tumors resulting from implantation of these cells were unaffected by retroviral transfection with the luciferase gene. As few as 1,000 cells could be reliably detected. The intensity of the bioluminescent signal correlated with the number of tumor cells in vitro. Photon emission in vivo and ex vivo correlated significantly with tumor weight at sacrifice. After intraperitoneal injection of luciferin there was a time dependent change in the intensity of the bioluminescent signal with maximum photon emission at 20 minutes (optimal 17 to 25).Luciferase transfected human renal cancer lines allow reliable, rapid, noninvasive and longitudinal monitoring of tumor growth in vivo. The ability to assess tumor development in vivo with time is economical and effective compared to end point data experiments.

    View details for Web of Science ID 000246635800082

    View details for PubMedID 17509355

  • A novel, semi quantitative, clinically correlated calcineurin inhibitor toxicity score for renal allograft biopsies CLINICAL JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY Kambham, N., Nagarajan, S., Shah, S., Li, L., Salvatierra, O., Sarwal, M. M. 2007; 2 (1): 135-142

    Abstract

    Calcineurin inhibitor toxicity (CNIT) is an important cause of chronic allograft nephropathy (CAN), but clinically relevant, diagnostic pathologic criteria remain to be defined. A semiquantitative, clinically correlative CNIT scoring system was developed and validated by pathologic analyses of 254 renal transplant biopsies that were obtained from 50 consecutive pediatric renal transplant recipients. Differentially weighted pathologic criteria (glomerulosclerosis, tubular atrophy, arteriolar medial hyaline, and tubular isometric vacuolization) contributed to the composite CNIT model score. Unlike other established pathology chronicity scores, such as the chronic allograft damage index, Banff, and modified Banff, the CNIT score was highly correlated with future graft function. The 3-mo CNIT score correlated significantly with 12 mo (P = 0.021) and 24 mo (P = 0.03) calculated creatinine clearance. Arteriolar medial hyalinosis seems to be the most important factor contributing to the clinical impact of the CNIT score.

    View details for DOI 10.2215/CJN.01320406

    View details for Web of Science ID 000243324500022

    View details for PubMedID 17699397

  • Evaluation of C4d staining in liver and small intestine allografts ARCHIVES OF PATHOLOGY & LABORATORY MEDICINE Troxell, M. L., Higgins, J. P., Kambham, N. 2006; 130 (10): 1489-1496

    Abstract

    Antibody-mediated humoral rejection in kidney and heart allografts is well recognized and is often associated with poor outcome. C4d deposition in allograft biopsy specimens occurs at sites of antibody-mediated complement activation and has become one of the histopathologic criteria for diagnosis of humoral rejection in the kidney and the heart.To study immunohistochemical C4d staining as a potential diagnostic marker in liver and small intestine allograft biopsy specimens.Thirty-six small intestine and 71 liver specimens, including native specimens, allografts with and without histologic features of acute cellular rejection, and explants, were stained with antisera to C4d using an immunohistochemical method on formalin-fixed, paraffin-embedded tissue.In small intestine, C4d labeled capillaries in 27% of cases with no evidence of rejection, 36% of cases with evidence of acute rejection, and 2 (28%) of 7 specimens of native normal small intestine. In liver allograft biopsy specimens, C4d stained endothelium of veins, arteries, and/or sinusoids in 2 (8%) of 25 cases of acute rejection with central vein involvement; C4d staining was negative in biopsy specimens with no evidence of rejection. C4d stained the endothelium in a subset of explanted liver allografts with ductopenic rejection or chronic vascular rejection and strongly stained 1 explant with features of hyperacute rejection.The clinical utility of C4d staining in solid organ transplantation may vary by organ. Our data show C4d is unlikely to have utility in small intestine allograft biopsy specimens; however, further study in liver allografts, in conjunction with donor-specific antibody testing, is warranted.

    View details for Web of Science ID 000241049200013

    View details for PubMedID 17090190

  • Concurrent anti-glomerular basement membrane disease and membranous glomerulonephritis: a case report and literature review CLINICAL NEPHROLOGY Troxell, M. L., Saxena, A. B., Kambham, N. 2006; 66 (2): 120-127

    Abstract

    Anti-glomerular basement membrane disease (anti-GBM) is a relatively rare entity characterized by antibodies to collagen type IV of glomerular and alveolar basement membranes. The sequential or simultaneous presentation of anti-glomerular basement membrane disease with membranous glomerulonephritis has been infrequently described.We present the case of a 49-year-old man who had fatigue, flank pain, hematuria and renal failure. Serology was positive for anti-GBM antibodies; crescentic glomerulonephritis was seen on renal biopsy. Immunofluorescence and electron microscopy demonstrated evidence of both anti-GBM glomerulonephritis and membranous deposits.Simultaneous anti-GBM disease and membranous glomerulonephritis is the most common temporal presentation of this rare entity. However, cases of membranous glomerulonephritis preceding or following recovery from anti-GBM disease have been described. Study of such cases provides insight into pathophysiologic mechanisms, including the possibility of increased antigen synthesis, exposure of cryptic epitopes, and/or capping and shedding of antigen-antibody complexes, in analogy to Heymann nephritis.

    View details for Web of Science ID 000239600200007

    View details for PubMedID 16939068

  • Connective tissue growth factor-specific monoclonal antibody therapy inhibits pancreatic tumor growth and metastasis CANCER RESEARCH Dornhoefer, N., Spong, S., Bennewith, K., Salim, A., Klaus, S., Kambham, N., Wong, C., Kaper, F., Sutphin, P., Nacalumi, R., Hoeckel, M., Le, Q., Longaker, M., Yang, G., Koong, A., Giaccia, A. 2006; 66 (11): 5816-5827

    Abstract

    Pancreatic cancer is highly aggressive and refractory to most existing therapies. Past studies have shown that connective tissue growth factor (CTGF) expression is elevated in human pancreatic adenocarcinomas and some pancreatic cancer cell lines. To address whether and how CTGF influences tumor growth, we generated pancreatic tumor cell lines that overexpress different levels of human CTGF. The effect of CTGF overexpression on cell proliferation was measured in vitro in monolayer culture, suspension culture, or soft agar, and in vivo in tumor xenografts. Although there was no effect of CTGF expression on proliferation in two-dimensional cultures, anchorage-independent growth (AIG) was enhanced. The capacity of CTGF to enhance AIG in vitro was linked to enhanced pancreatic tumor growth in vivo when these cells were implanted s.c. in nude mice. Administration of a neutralizing CTGF-specific monoclonal antibody, FG-3019, had no effect on monolayer cell proliferation, but blocked AIG in soft agar. Consistent with this observation, anti-CTGF treatment of mice bearing established CTGF-expressing tumors abrogated CTGF-dependent tumor growth and inhibited lymph node metastases without any toxicity observed in normal tissue. Together, these studies implicate CTGF as a new target in pancreatic cancer and suggest that inhibition of CTGF with a human monoclonal antibody may control primary and metastatic tumor growth.

    View details for DOI 10.1158/0008-5472.CAN-06-0081

    View details for Web of Science ID 000238003100038

    View details for PubMedID 16740721

  • Comparison of C4d immunostaining methods in renal allograft biopsies CLINICAL JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY Troxell, M. L., Weintraub, L. A., Higgins, J. P., Kambham, N. 2006; 1 (3): 583-591

    Abstract

    Immunostaining of renal allograft biopsies for C4d deposition has become an important diagnostic tool in the recognition of humoral-mediated graft rejection. The majority of studies have been performed on frozen tissue sections with one of several commercially available antibody reagents. However, only a single small series that compared reagents or methods, including staining of formalin-fixed, paraffin-embedded tissue, has been published. Two different staining methods in 138 renal allograft biopsies were compared directly: A mAb (Quidel, San Diego, CA) on frozen tissue sections with indirect immunofluorescence (IF) and a polyclonal antibody (Biomedica Gruppe, distributed by ALPCO, Windham, NH) applied to formalin-fixed, paraffin-embedded tissue with immunohistochemical (IHC) detection. An initial data set of 107 consecutive cases showed complete agreement between staining methods in 104 (97%) cases. Overall, nine of 107 cases were positive with one or both methods, representing 8.4% of all allograft biopsies tested, 15% of clinically indicated biopsies, and 24% of biopsies with a histologic diagnosis of acute cellular rejection. A second set of 31 cases included 17 cases that were positive by either method, with concordance in 29 of 31 cases. Combining the two data sets, the overall specificity of the IHC method compared with IF was 98%, and sensitivity was 87.5%. Direct comparison demonstrates that IHC staining of formalin-fixed, paraffin-embedded tissue with anti-C4d polyclonal antibody has acceptable sensitivity and specificity, as compared with IF staining of frozen tissue with the Quidel mAb.

    View details for Web of Science ID 000242172900035

    View details for PubMedID 17699262

  • Utility of syndecan-1 (CD138) expression in the diagnosis of undifferentiated malignant neoplasms - A tissue microarray study of 1,754 cases APPLIED IMMUNOHISTOCHEMISTRY & MOLECULAR MORPHOLOGY Kambham, N., Kong, C., Longacre, T. A., Natkunam, Y. 2005; 13 (4): 304-310

    Abstract

    Syndecan-1, a heparan sulfate-rich membrane glycoprotein, is expressed in plasma cells and is considered a reliable marker of plasmacytic differentiation. However, it has not been widely tested in non-hematolymphoid tissues, and thus its utility in the setting of an undifferentiated malignant neoplasm has not been evaluated. The authors conducted an extensive study of CD138 staining in over 1,700 normal, benign, and malignant non-hematolymphoid tissues, using five tissue microarrays. Immunohistochemical staining was performed with two commercially available CD138 monoclonal antibodies directed against syndecan-1 (Serotec, Oxford, UK, and DAKO, Carpenteria, CA). In addition to the specific membrane staining, many normal tissues and epithelial tumors showed strong cytoplasmic immunoreactivity. A small subset of mesenchymal neoplasms also showed membrane and cytoplasmic immunoreactivity. In squamous cell carcinoma of the head and neck, renal cell carcinoma, and prostate adenocarcinoma, the intensity of CD138 staining inversely correlated with the histologic grade of the carcinoma. However, statistically significant staining differences and their correlation with histologic grades differed depending on whether the Serotec or the DAKO antibody was used. These results indicate that CD138 immunoreactivity is widespread in normal and neoplastic epithelial tissues, as well as a variety of undifferentiated epithelial and mesenchymal processes. The authors conclude that the expression of syndecan-1, although relatively specific to plasma cells within the hematolymphoid system, should be interpreted with extreme caution in the setting of an undifferentiated neoplasm. Furthermore, the two commercially available monoclonal CD138 antibodies tested in this study showed significant differences in their immunoreactivity in different tumor types.

    View details for Web of Science ID 000233572700002

    View details for PubMedID 16280658

  • Multinucleated epithelial giant cells in colorectal polyps - A potential mimic of viropathic and/or dysplastic changes AMERICAN JOURNAL OF SURGICAL PATHOLOGY Kambham, N., Troxell, M., Longacre, T. A. 2005; 29 (7): 912-919

    Abstract

    Multinucleated epithelial giant cells (MEG) simulating viral cytopathic effect and/or dysplasia have been reported in the esophagus in association with inflammation, but the occurrence of similar cells in the colon has not been documented. Twenty-three colon specimens (22 biopsies and 1 partial colectomy) featuring MEG from 21 patients were evaluated for a variety of histologic features and correlated with clinical, endoscopic, and follow-up data. Patients included 9 males and 12 females (mean age, 64.9 years; range, 45-86 years). Eleven cases were obtained from 10 asymptomatic patients undergoing surveillance biopsies. Presenting symptoms in the remaining patients were dyspepsia, anemia, abdominal pain, and hematochezia. Over half (13 of 23) of the specimens were from descending and rectosigmoid colon, and almost all were visualized as polyps on endoscopy. Microscopically, all but 1 of the cases featured multiple MEG (range, 6 to >50 cells per biopsy) in the base and mid crypt zones of inflamed polyps with serrated architecture. Immunohistochemical stains for CMV, HSV, adenovirus, EBV, and polyoma virus were negative and no viral particles were identified on ultrastructural examination. Nuclear staining for hMLH1 and hMSH2, markers of microsatellite instability, was similar in distribution to adjacent serrated crypts, but reduced staining intensity was noted in occasional multinucleated cells. Expression of Ki-67 and cleaved caspase 3 was consistent with a quiescent or low proliferative state. Clinical follow-up was available for 9 patients (mean duration, 22.7 months). One patient died of heart failure; all others were well at last follow-up. Bizarre MEG may occasionally be seen within the crypts of inflamed polyps with serrated architecture, raising concern for dysplasia or viral infection. Immunohistochemical and ultrastructural studies fail to establish a viral etiology, and follow-up does not indicate clinically aggressive disease. These changes appear to represent a nonspecific, possibly degenerative response to inflammation and injury, and should be distinguished from dysplasia.

    View details for Web of Science ID 000230102600009

    View details for PubMedID 15958856

  • Gastrointestinal leukocytoclastic vasculitis: An adverse effect of sirolimus PEDIATRIC TRANSPLANTATION Nagarajan, S., Friedrich, T., Garcia, M., Kambham, N., Sarwal, M. M. 2005; 9 (1): 97-100

    Abstract

    An 18-yr-old Hispanic female with end-stage renal disease secondary to chronic glomerulonephritis of unknown etiology underwent cadaveric renal transplantation. She was placed on a steroid-free protocol with tacrolimus and mycophenolate mofetil (MMF) for maintenance immunosuppression. Approximately 8 months post-transplantation, MMF was replaced by sirolimus (SRL) because of persistent leukopenia. Four months after the initiation of SRL, the patient began to experience chronic, constant periumbilical abdominal pain in the absence of vomiting, diarrhea or melena. Esophagogastroduodenoscopy and CT scans revealed significant diffuse mucosal thickening of the antrum, duodenum, and jejunum; leukocytoclastic vasculitis was identified on antral biopsy. A repeat biopsy after reduction of sirolimus dose by 50% over 6 months showed mild chronic inflammation of stomach and duodenum with some improvement in abdominal pain. Discontinuation of SRL and replacement with low dose MMF resulted in complete resolution of pain and normalization of gastrointestinal anatomy by imaging studies within 2 months. In light of this report, drug-induced leukocytoclastic vasculitis caused by SRL should be considered in the differential diagnosis of chronic abdominal pain in a patient with organ transplantation.

    View details for DOI 10.1111/j.1399-3046.2005.00245.x

    View details for Web of Science ID 000226511800019

    View details for PubMedID 15667620

  • Cytomegalovirus infection in steroid-refractory ulcerative colitis - A case-control study AMERICAN JOURNAL OF SURGICAL PATHOLOGY Kambham, N., Vij, R., Cartwright, C. A., Longacre, T. 2004; 28 (3): 365-373

    Abstract

    Cytomegalovirus (CMV) infection is reported to be a cause of steroid-refractory ulcerative colitis (UC), but the strength of this association has not been tested in a case control study. Controlled studies have also not been performed to determine the sensitivity of available immunohistochemical techniques to detect CMV in this setting. The pathology database at Stanford Hospital was searched for UC patients with a diagnosis of "severe colitis" between the years 1992 and 2002 and medical records were reviewed. Forty patients were identified with refractory UC, defined as poor response to highdose systemic steroids for >2 weeks. Another group of 40 patients with severe, but nonrefractory, UC was case-matched for age and year of biopsy. A series of 40 patients who underwent colectomy for reasons other than inflammatory bowel disease with representative sections of "normal" colon were selected as noncolitis controls. CMV inclusions were detected on hematoxylin and eosin (H&E) in 2 of 40 patients with refractory UC, but not in other patients. Immunohistochemistry (IHC) detected CMV in 10 of 40 (25%) patients with refractory UC and 1 of 40 (2.5%) patients with nonrefractory UC (P = 0.007). The CMV-positive cases initially identified on IHC but not on H&E were re-reviewed for viral inclusions on H&E: 3 had rare, but typical, inclusions; 3 had atypical inclusions; and 3 had no inclusions. CMV was not detected by H&E or IHC in 40 noncolitis controls. Of 10 steroid-refractory UC patients with CMV detected, 7 were refractory to cyclosporin or 6-mercaptopurine/azathioprine (70%) and 6 had undergone proctocolectomy (60%) prior to detection of the CMV. Two patients with recognized CMV infection were treated with gancyclovir, improved, and were able to taper off steroids and avoid proctocolectomy. This study provides evidence that unrecognized and therefore untreated CMV infection is significantly associated with steroid-refractory UC. Moreover, IHC is more sensitive than H&E for detection of CMV and should be considered as part of the routine evaluation of steroid-refractory UC patients, before proceeding with other medical or surgical therapy that may be unnecessary once the CMV is treated.

    View details for Web of Science ID 000189316500009

    View details for PubMedID 15104299

  • Gene expression in the normal adult human kidney assessed by complementary DNA microarray MOLECULAR BIOLOGY OF THE CELL Higgins, J. P., Wang, L. L., Kambham, N., Montgomery, K., Mason, V., Vogelmann, S. U., Lemley, K. V., Brown, P. O., Brooks, J. D., van de Rijn, M. 2004; 15 (2): 649-656

    Abstract

    The kidney is a highly specialized organ with a complex, stereotyped architecture and a great diversity of functions and cell types. Because the microscopic organization of the nephron, the functional unit of the kidney, has a consistent relationship to the macroscopic anatomy of the kidney, knowledge of the characteristic patterns of gene expression in different compartments of the kidney could provide insight into the functions and functional organization of the normal nephron. We studied gene expression in dissected renal lobes of five adult human kidneys using cDNA microarrays representing approximately 30,000 different human genes. Total RNA was isolated from sections of the inner and outer cortex, inner and outer medulla, papillary tips, and renal pelvis and from glomeruli isolated by sieving. The results revealed unique and highly distinctive patterns of gene expression for glomeruli, cortex, medulla, papillary tips, and pelvic samples. Immunohistochemical staining using selected antisera confirmed differential expression of several cognate proteins and provided histological localization of expression within the nephron. The distinctive patterns of gene expression in discrete portions of the kidney may serve as a resource for further understanding of renal physiology and the molecular and cellular organization of the nephron.

    View details for DOI 10.1091/mbc.E03-06-0432

    View details for Web of Science ID 000188718900024

    View details for PubMedID 14657249

  • A randomized, placebo-controlled trial of IGF-1 for delayed graft function: A human model to study postischemic ARF KIDNEY INTERNATIONAL Hladunewich, M. A., Corrigan, G., Derby, G. C., Ramaswamy, D., Kambham, N., Scandling, J. D., Myers, B. D. 2003; 64 (2): 593-602

    Abstract

    Insulin-like growth factor (IGF-1) has been shown in animal models to accelerate recovery from acute renal failure (ARF). However, a therapeutic trial of recombinant human (rh) IGF-1 in patients with ARF in the intensive care unit (ICU) failed to demonstrate efficacy [1]. Such patients often had multiple organ failure, recurrent renal injury, and a delay of several days before commencing treatment.To circumvent these confounding factors, we randomized recipients of cadaveric renal allografts to immediate (<5 hours) rhIGF-1 versus placebo therapy (100 mg/kg subcutaneously twice a day for 6 days). Preliminary observations 3 hours posttransplantation in an additional 44 patients revealed a creatinine clearance < or = 20 mL/min to predict protracted ARF. Thus, this value was used to determine study eligibility.Creatinine clearance prior to commencing treatment was not significantly different between the two groups (8 +/- 5 mL/min for IGF-1 and 7 +/- 6 mL/min for placebo; P = 0.39). Inulin clearance on day 7, the primary outcome measure, was 21 +/- 22 mL/min and 19 +/- 19 mL/min in the IGF-1 (N = 19) and placebo (N = 24) groups, respectively (P = 0.67). Secondary outcome measures, including nadir serum creatinines after 6 weeks and need for dialysis, also did not differ between the two groups. We performed an analysis of statistical power using the placebo arm of the trial. Defining a twofold increase above placebo in day 7 glomerular filtration rate (GFR) as of meaningful biologic significance, we determined that the modest sample size used in the present study is adequate.We, thus, conclude that (1) IGF-1 treatment is unlikely to benefit ARF and (2) the transplanted kidney is a good model to screen new agents for ARF that have demonstrated promise in animal trials.

    View details for Web of Science ID 000183966500022

    View details for PubMedID 12846755

  • Molecular heterogeneity in acute renal allograft rejection identified by DNA microarray profiling NEW ENGLAND JOURNAL OF MEDICINE Sarwal, M., Chua, M. S., Kambham, N., Hsieh, S. C., Satterwhite, T., Masek, M., Salvatierra, O. 2003; 349 (2): 125-138

    Abstract

    The causes and clinical course of acute rejection vary, and it is not possible to predict graft outcome reliably on the basis of available clinical, pathological, and genetic markers. We hypothesized that previously unrecognized molecular heterogeneity might underlie some of the variability in the clinical course of acute renal allograft rejection and in its response to treatment.We used DNA microarrays in a systematic study of gene-expression patterns in biopsy samples from normal and dysfunctional renal allografts. A combination of exploratory and supervised bioinformatic methods was used to analyze these profiles.We found consistent differences among the gene-expression patterns associated with acute rejection, nephrotoxic effects of drugs, chronic allograft nephropathy, and normal kidneys. The gene-expression patterns associated with acute rejection suggested at least three possible distinct subtypes of acute rejection that, although indistinguishable by light microscopy, were marked by differences in immune activation and cellular proliferation. Since the gene-expression patterns pointed to substantial variation in the composition of immune infiltrates, we used immunohistochemical staining to define these subtypes further. This analysis revealed a striking association between dense CD20+ B-cell infiltrates and both clinical glucocorticoid resistance (P=0.01) and graft loss (P<0.001).Systematic analysis of gene-expression patterns provides a window on the biology and pathogenesis of renal allograft rejection. Biopsy samples from patients with acute rejection that are indistinguishable on conventional histologic analysis reveal extensive differences in gene expression, which are associated with differences in immunologic and cellular features and clinical course. The presence of dense clusters of B cells in a biopsy sample was strongly associated with severe graft rejection, suggesting a pivotal role of infiltrating B cells in acute rejection.

    View details for Web of Science ID 000184024400005

    View details for PubMedID 12853585

  • Surgical robotic applications in otolaryngology LARYNGOSCOPE Haus, B. M., Kambham, N., Le, D., Moll, F. M., Gourin, C., Terris, D. J. 2003; 113 (7): 1139-1144

    Abstract

    To explore the feasibility of performing endo-robotic neck surgery in a porcine model and to compare the results of robotically enhanced endoscopic surgery with those from a conventional endoscopic technique.Prospective, nonrandomized experimental investigation in a porcine model.We performed a consecutive series of endoscopic neck surgeries using the daVinci surgical system (Intuitive Surgical Inc.). The length of time required to establish the operative pocket and to assemble the robotic components, as well as the total duration of each operation, was recorded. The animals were continuously monitored for heart rate, blood pressure, and end-tidal CO(2) pressure, and evaluation for presence of pneumothorax and subcutaneous emphysema was undertaken postoperatively. The specimens were examined histologically.Four different types of neck surgery were successfully performed on both sides of the neck of four animals using the daVinci surgical system. Creation of the operative pocket took, on average (+/-SD), 18.1 +/- 11.9 minutes, and assembly of the robot required 12.5 +/- 9.9 minutes, resulting in a mean preparation time for all procedures of 30.6 +/- 21.0 minutes. The mean operative time for submandibular resection (n = 3) was 19.0 +/- 6.6 minutes, with a total procedure time of 39.0 +/- 10.2 minutes. Selective neck dissections (n = 3) required a mean operative time of 66.0 +/- 18.5 minutes and a total procedure time of 85.7 +/- 16.7 minutes. One partial parotidectomy and one thymectomy were also performed. The median estimated blood loss was 0 mL (range, 0-10 mL). The end-tidal CO(2) pressure fell from the start to the end of the procedures by a mean of 4.4 +/- 7.9 mm Hg. The blood pressure fell by a mean of 1.9 +/- 7.5 mm Hg. There was one case of modest subcutaneous emphysema, and there were no cases of pneumothorax or air embolism. No conversions to open resection were necessary.Robotically enhanced endoscopic surgery in the neck is feasible and offers a number of compelling advantages over conventional endoscopic neck surgery. Clinical trials will be necessary to determine whether these advantages can be achieved in clinical practice.

    View details for Web of Science ID 000184139500008

    View details for PubMedID 12838011

  • Endoscopic selective neck dissection in a porcine model ARCHIVES OF OTOLARYNGOLOGY-HEAD & NECK SURGERY Terris, D. J., Monfared, A., Thomas, A., Kambham, N., Saenz, Y. 2003; 129 (6): 613-617

    Abstract

    To investigate the feasibility of accomplishing a selective neck dissection (SND) endoscopically.Prospective, nonrandomized experimental investigation in a porcine model.Unilateral endoscopic SNDs were performed in Yorkshire pigs. A spacious operative pocket was developed using a combination of hernia balloon expansion followed by low-pressure (4 mm Hg) carbon dioxide insufflation. The sternomastoid muscle, thymus, submandibular gland, lymph nodes, and fibrofatty tissue were removed in a procedure approximating a human SND. Data (operative time, blood loss, arterial blood gas values, weight of the specimen, and complications) were prospectively recorded. The specimens were analyzed by a pathologist, and the number and size of lymph nodes were recorded.Fourteen endoscopic SNDs were successfully performed. No conversions to open surgery were necessary. The median operative time was 131 minutes (range, 95-235 minutes). The median estimated blood loss was 4 mL (range, 0-150 mL). The mean +/- SD specimen weight was 42.9 +/- 8.3 g; the mean number +/- SD of nodes retrieved from the neck specimen was 4.8 +/- 2.2, and the mean +/- SD maximal nodal dimension was 2.4 +/- 0.5 cm. The arterial PCO2 increased by an average of only 3.9 mm Hg from the beginning to the end of the surgery; correspondingly, the pH fell by only 0.02. There were no major complications, and no animals had to be euthanized prior to the completion of the procedure.Endoscopic neck dissection in a porcine model can be accomplished with a combination of strategies to overcome the dilemma of creating and maintaining an operative pocket. The merger of SND with endoscopic technology offers the promise of truly minimally invasive surgery for the node-negative neck.

    View details for Web of Science ID 000183409600003

    View details for PubMedID 12810462

  • Adefovir nephrotoxicity: Possible role of mitochondrial DNA depletion HUMAN PATHOLOGY Tanji, N., Tanji, K., Kambham, N., Markowitz, G. S., Bell, A., D'Agati, V. D. 2001; 32 (7): 734-740

    Abstract

    This report investigates the pathomechanism of acute renal failure caused by toxic acute tubular necrosis after treatment with the antiretroviral agent adefovir. A 38-year-old white homosexual man with human immunodeficiency virus infection and no history of opportunistic infections was maintained on highly active antiretroviral therapy (HAART), including hydroxyurea, stavudine, indinavir, ritonavir, and adefovir dipivoxil. Histologic examination of the renal biopsy showed severe acute tubular degenerative changes primarily affecting the proximal tubules. On ultrastructural examination, proximal tubular mitochondria were extremely enlarged and dysmorphic with loss and disorientation of their cristae. Functional histochemical stains for mitochondrial enzymes revealed focal tubular deficiency of cytochrome C oxidase (COX), a respiratory chain enzyme partially encoded by mitochondrial DNA (mtDNA), with preservation of succinate dehydrogenase, a respiratory chain enzyme entirely encoded by nuclear DNA (nDNA). Immunoreactivity for COX subunit I (encoded by mtDNA) was weak to undetectable in most tubular epithelial cells, although immunoreactivities for COX subunit IV and iron sulfur subunit of respiratory complex III (both encoded by nDNA) were well preserved in all renal tubular cells. Single-renal tubule polymerase chain reaction revealed marked reduction of mtDNA in COX-immunodeficient renal tubules. We conclude that adefovir-induced nephrotoxicity is mediated by depletion of mtDNA from proximal tubular cells through inhibition of mtDNA replication. This novel form of nephrotoxicity may serve as a prototype for other forms of renal toxicity caused by reverse transcriptase inhibitors.

    View details for DOI 10.1053/hupa.2001.25586

    View details for Web of Science ID 000170159100010

    View details for PubMedID 11486172

  • Renal monoclonal immunoglobulin deposition disease: The disease spectrum JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY Lin, J., Markowitz, G. S., Valeri, A. M., Kambham, N., Sherman, W. H., Appel, G. B., D'Agati, V. D. 2001; 12 (7): 1482-1492

    Abstract

    This study reports the clinicopathologic findings and outcome in 34 patients with renal monoclonal immunoglobulin deposition disease (MIDD), which included 23 light-chain DD (LCDD), 5 light- and heavy-chain DD (LHCDD), and 6 heavy-chain DD (HCDD). A total of 23 patients had pure MIDD, whereas 11 patients had LCDD with coexistent myeloma cast nephropathy (LCDD & MCN). Renal biopsy diagnosis preceded clinical evidence of dysproteinemia in 68% of all cases. By immunofluorescence, the composition of deposits included 11kappa/1lambda (LCDD), 3IgGkappa/2IgGlambda (LHCDD), 5gamma/1alpha (HCDD), and 10kappa/1lambda (LCDD & MCN). Patients with pure MIDD presented with mean serum creatinine of 4.2 mg/dl, nephrotic proteinuria, and hypertension. Cases of HCDD were associated with a CH1 deletion and frequently had hypocomplementemia and a positive hepatitis C virus antibody but negative hepatitis C virus PCR. LCDD & MCN is a morphologically and clinically distinct entity from pure MIDD, presenting with higher creatinine (mean, 7.8 mg/dl; P = 0.01), greater dialysis dependence (64 versus 26%; P = 0.053), subnephrotic proteinuria, and less nodular glomerulopathy (18 versus 100%; P < 0.0001). Multiple myeloma was more frequently diagnosed in LCDD & MCN than in pure MIDD (91 versus 31%; P = 0.025). Renal and patient survivals were significantly worse in patients with LCDD & MCN (mean, 4 and 22 mo, respectively), compared with patients with pure MIDD (mean, 22 and 54 mo). Chemotherapy stabilized or improved renal function in 10 of 15 patients (67%) with pure MIDD who presented with creatinine of <5.0 mg/dl, emphasizing the importance of early detection. On multivariate analysis, initial creatinine was the only predictor of renal and patient survival in pure MIDD, underscoring the prognostic significance of the renal involvement.

    View details for Web of Science ID 000169539800017

    View details for PubMedID 11423577

  • Obesity-related glomerulopathy: An emerging epidemic KIDNEY INTERNATIONAL Kambham, N., Markowitz, G. S., Valeri, A. M., Lin, J., D'Agati, V. D. 2001; 59 (4): 1498-1509

    Abstract

    We report the first large renal biopsy-based clinicopathologic study on obesity-related glomerulopathy.Obesity was defined as body mass index (BMI)> 30 kg/m2. Obesity-related glomerulopathy (ORG) was defined morphologically as focal segmental glomerulosclerosis and glomerulomegaly (O-FSGS; N = 57) or glomerulomegaly alone (O-GM; N = 14).Review of 6818 native renal biopsies received from 1986 to 2000 revealed a progressive increase in biopsy incidence of ORG from 0.2% in 1986-1990 to 2.0% in 1996-2000 (P = 0.0001). Mean BMI in ORG was 41.7 (range 30.9 to 62.7). Indications for renal biopsy included proteinuria (N = 40) or proteinuria and renal insufficiency (N = 31). Seventy-one patients with ORG were compared to 50 patients with idiopathic FSGS (I-FSGS). Patients with ORG were older (mean 42.9 vs. 32.6 years, P < 0.001) and more often Caucasian (75% vs. 52%; P = 0.003). ORG patients had a lower incidence of nephrotic range proteinuria (48% vs. 66%; P = 0.007) and nephrotic syndrome (5.6% vs. 54%; P < 0.001), with higher serum albumin (3.9 vs. 2.9 g/dL; P < 0.001), lower serum cholesterol (229 vs. 335 mg/dL; P < 0.001), and less edema (35% vs. 68%; P = 0.003). On renal biopsy, patients with ORG had fewer lesions of segmental sclerosis (10 vs. 39%; P < 0.001), more glomerulomegaly (100% vs. 10%; P < 0.001), and less extensive foot process effacement (40 vs. 75%; P < 0.001). Glomerular diameter in ORG (mean 226 mu) was significantly larger than age- and sex-matched normal controls (mean 168 mu; P < 0.001). Follow-up was available in 56 ORG patients (mean 27 months) and 50 idiopathic FSGS controls (mean 38 months). A total of 75% of ORG patients received angiotensin-converting enzyme (ACE) inhibition or A2 blockade while 78% of the I-FSGS patients received immunosuppressive therapy. ORG patients had less frequent doubling of serum creatinine (14.3% vs. 50%; P < 0.001) and progression to ESRD (3.6% vs. 42%; P < 0.001). On multivariate analysis, presenting serum creatinine and severity of proteinuria were the only predictors of poor outcome in ORG.ORG is distinct from idiopathic FSGS, with a lower incidence of nephrotic syndrome, more indolent course, consistent presence of glomerulomegaly, and milder foot process fusion. The ten-fold increase in incidence over 15 years suggests a newly emerging epidemic. Heightened physician awareness of this entity is needed to ensure accurate diagnosis and appropriate therapy.

    View details for Web of Science ID 000167737200034

    View details for PubMedID 11260414

  • A 51-year-old female with nephrotic syndrome, renal failure, and hepatitis C virus infection AMERICAN JOURNAL OF KIDNEY DISEASES Markowitz, G. S., Kaur, P., Orazi, A., Kambham, N., Cheng, J. T., Prial, M. M., Pogue, V. A., D'Agati, V. D. 2001; 37 (2): 442-447

    View details for Web of Science ID 000166647400029

    View details for PubMedID 11157391

  • Idiopathic hypocomplementemic interstitial nephritis with extensive tubulointerstitial deposits AMERICAN JOURNAL OF KIDNEY DISEASES Kambham, N., Markowitz, G. S., Tanji, N., Mansukhani, M. M., Orazi, A., D'Agati, V. D. 2001; 37 (2): 388-399

    Abstract

    Most forms of interstitial nephritis are cell mediated and lack tubulointerstitial immune deposits. These forms include allergic, infectious, and idiopathic interstitial nephritis. Immune complex deposits in the tubular basement membranes and interstitium most commonly are encountered in conjunction with glomerular diseases. Predominantly tubulointerstitial immune deposits without significant glomerular involvement can occur in Sjögren's syndrome and in a small subset of lupus nephritis. We report eight unusual cases of tubulointerstitial nephritis with massive tubulointerstitial immune deposits occurring in adults with hypocomplementemia and no evidence of systemic lupus erythematosus or Sjögren's disease. Most patients were older men. The renal biopsy specimens manifested a spectrum of changes ranging from tubulointerstitial nephritis to atypical lymphoid hyperplasia to changes suggestive of marginal zone B-cell lymphoma. Chronic local antigenic stimulation may predispose to lymphoma in these cases, analogous to what is postulated to occur in cases of mucosa-associated lymphoid tissue (MALT) lymphomas in extranodal sites, such as salivary gland, stomach, and thyroid. The preferential tubulointerstitial immune deposition and significant interstitial plasma cell component suggest pathomechanisms that involve local immune complex formation.

    View details for Web of Science ID 000166647400019

    View details for PubMedID 11157382

  • Membranous glomerulopathy with Bowman's capsular and tubular basement membrane deposits CLINICAL NEPHROLOGY Markowitz, G. S., Kambham, N., Maruyama, S., Appel, G. B., Cohen, D. J., Kim, R. C., Andres, G. A., D'Agati, V. D. 2000; 54 (6): 478-486

    Abstract

    Bowman's capsular and tubular basement membrane (TBM) deposits are an extremely unusual finding in non-lupus membranous glomerulopathy (MGN). We report three atypical cases of MGN with abundant Bowman's capsular and TBM deposits. In two cases, MGN was idiopathic; in the third case, MGN occurred in the renal allograft in the setting of HCV seropositivity. In addition to the usual glomerular capillary wall deposits, immunofluorescence and electron microscopy revealed extensive immune deposits within Bowman's capsule and TBMs, predominantly at the base of parietal and tubular epithelial cells. These cases suggest a potential pathomechanism of autoantibody to secreted epithelial antigens shared by visceral, parietal, and tubular epithelial cells. In all three cases, indirect immunofluorescence was unable to detect autoantibody to normal renal epithelial or matrix constituents. Furthermore, ELISA was unable to demonstrate circulating antibody to major extracellular matrix components. The implications of these findings for the pathogenesis of MGN are explored.

    View details for Web of Science ID 000165801100007

    View details for PubMedID 11140809

  • Should a Gleason score be assigned to a minute focus of carcinoma on prostate biopsy? AMERICAN JOURNAL OF SURGICAL PATHOLOGY Rubin, M. A., Dunn, R., Kambham, N., Misick, C. P., O'Toole, K. M. 2000; 24 (12): 1634-1640

    Abstract

    The grading system for prostate carcinoma devised by Gleason is a strong prognostic indicator. The primary and secondary patterns are combined to give a tumor score, referred to as Gleason score or sum. Gleason scores on biopsy correlate with the prostatectomy Gleason scores, and in combination with pretreatment serum prostate-specific antigen and digital rectal examination results, predict tumor stage and lymph node status. However, when only a minute focus of tumor is present on biopsy, the Gleason score is assigned by doubling the Gleason pattern. The goal of this study was to determine if a Gleason score assigned to a minimal focus of adenocarcinoma had predictive value. Paired biopsies and prostatectomy specimens from 963 cases of men with clinically localized prostate cancer were examined. Minimal tumor on biopsy was defined as less than 1 mm or 5% involvement of one biopsy core; excluded from this definition were biopsies where two Gleason patterns could be identified and/or tumor was seen on more than one biopsy core. Terms often used to describe these lesions include "single minute focus of carcinoma" or "adenocarcinoma, too small to give a Gleason grade." One hundred five cases (10.9%) met the above criteria for minimal carcinoma. The correlation of Gleason scores between biopsies and prostatectomy specimens overall was good with exact agreement for 57% of cases and a difference of +/-1 unit in 92% of cases. The correlation for the minimal tumors on biopsy and prostatectomy was slightly worse with exact agreement in 52.4% (55 of 105) and a difference of +/-1 unit in 87.6% (92 of 105). The majority of minimal tumors (83.8% or 88 of 105) were assigned a Gleason score of 6. A total of 31.8% of these 88 cases were upgraded and 5.7% were downgraded. Multivariate analysis on all cases looking for predictors of tumor stage found biopsy Gleason score, perineural invasion, pretreatment prostatic-specific antigen, and digital rectal examination all predicted higher tumor stage with odds ratios of 1.86 (95% confidence interval [CI], 1.53-2.27; p = 0.0001), 2.06 (95% CI, 1.43-2.95; p = 0.0001), 1.08 (95% CI, 1.05-1.11; p = 0.0001), and 1.41 (95% CI, 1.04-1.91; p = 0.0289), respectively. In a model restricted to the 105 cases with minimal carcinoma, pretreatment prostatic-specific antigen was the only independent predictor of higher tumor stage with an odds ratio of 1.15 (95% CI, 1.01-1.31; p = 0.0380); Gleason score was not found to significantly predict higher tumor stage (odds ratio, 1.156; p = 0.6680). The results of this study confirm that biopsy Gleason score in most cases predicts prostatectomy Gleason score and tumor stage. However, for cases with minimal tumor on biopsy, the assigned Gleason score did not predict tumor stage. To properly convey this uncertainty to clinicians, a cautionary note should accompany Gleason scores derived from a minimal focus of carcinoma.

    View details for Web of Science ID 000165590400007

    View details for PubMedID 11117784

  • An 18-year-old female with acute onset of nephrotic syndrome AMERICAN JOURNAL OF KIDNEY DISEASES Kambham, N., Markowitz, G. S., Slater, L. M., D'Agati, V. D. 2000; 36 (2): 441-446

    View details for Web of Science ID 000089227100029

    View details for PubMedID 10922326

  • Lithium nephrotoxicity: A progressive combined glomerular and tubulointerstitial nephropathy JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY Markowitz, G. S., Radhakrishnan, J., Kambham, N., Valeri, A. M., Hines, W. H., D'Agati, V. D. 2000; 11 (8): 1439-1448

    Abstract

    This study examines the clinical features, pathologic findings, and outcome of 24 patients with biopsy-proven lithium toxicity. The patient population was 50% male, 87.5% Caucasian, and had a mean age of 42.5 yr (range, 26 to 57). Mean duration of lithium therapy for bipolar disorder was 13.6 yr (range, 2 to 25). All patients were biopsied for renal insufficiency (mean serum creatinine 2.8 mg/dl; range, 1.3 to 8.0), with associated proteinuria >1.0 g/d in 41.7%. Nephrotic proteinuria (>3.0 g/d) was present in 25%. Other features included nephrogenic diabetes insipidus in 87% and hypertension in 33.3%. Renal biopsy revealed a chronic tubulointerstitial nephropathy in 100%, with associated cortical and medullary tubular cysts (62.5%) or dilatation (33.3%). All of the renal cysts stained for epithelial membrane antigen, while 51.4% stained with lectin Arachis hypogaea, and only 3.8% stained with Tetragonolobus purpureas, indicating they originated from distal and collecting tubules. The degree of tubular atrophy and interstitial fibrosis was graded as severe in 58.3%, moderate in 37.5%, and mild in 4.2% of cases. There was a surprisingly high prevalence of focal segmental glomerulosclerosis (50%) and global glomerulosclerosis (100%), sometimes of equivalent severity to the chronic tubulointerstitial disease. The significant degree of foot process effacement (mean 34%, five of 14 cases with >50%) suggests a potential direct glomerular toxicity. Focal segmental glomerulosclerosis correlated with proteinuria >1.0 g/d (P = 0.0014, Fisher exact test). Despite discontinuation of lithium, seven of nine patients with initial serum creatinine values >2.5 mg/dl progressed to end-stage renal disease (ESRD). Only three patients, all with initial serum creatinine <2.1 mg/dl, had subsequent improvement in renal function. By Kaplan-Meier survival analysis, the only significant predictor of progression to ESRD was serum creatinine >2.5 mg/dl at biopsy (P = 0. 008). In conclusion, lithium nephrotoxicity primarily targets distal and collecting tubules, with a higher incidence of proteinuria and associated glomerular pathology than recognized previously. Renal dysfunction is often irreversible despite lithium withdrawal, and early detection is essential to prevent progression to ESRD.

    View details for Web of Science ID 000088340900008

    View details for PubMedID 10906157

  • Congenital focal segmental glomerulosclerosis associated with beta 4 integrin mutation and epidermolysis bullosa AMERICAN JOURNAL OF KIDNEY DISEASES Kambham, N., Tanji, N., Seigle, R. L., Markowitz, G. S., Pulkkinen, L., UITTO, J., D'Agati, V. D. 2000; 36 (1): 190-196

    Abstract

    We report the occurrence of congenital nephrotic-range proteinuria secondary to focal segmental glomerulosclerosis in an infant with epidermolysis bullosa and pyloric atresia. A homozygous missense mutation, R1281W, in exon 31 of the beta4 integrin gene, ITGB4, was identified. By immunofluorescence, beta4 integrin expression was reduced in both dermal keratinocytes and glomerular podocytes. This is the first demonstration of beta4 integrin expression in human glomeruli. We postulate a role for altered beta4 integrin function in the mediation of the glomerular permeability defect.

    View details for Web of Science ID 000088007700026

    View details for PubMedID 10873890

  • Fanconi syndrome with free kappa light chains in the urine AMERICAN JOURNAL OF KIDNEY DISEASES Markowitz, G. S., Flis, R. S., Kambham, N., D'Agati, V. D. 2000; 35 (4): 777-781

    View details for Web of Science ID 000086223700033

    View details for PubMedID 10739805

  • RAGE mediates a novel proinflammatory axis: A central cell surface receptor for S100/calgranulin polypeptides CELL Hofmann, M. A., Drury, S., Fu, C. F., Qu, W., Taguchi, A., Lu, Y., Avila, C., Kambham, N., Bierhaus, A., Nawroth, P., Neurath, M. F., Slattery, T., Beach, D., McClary, J., Nagashima, M., MORSER, J., Stern, D., Schmidt, A. M. 1999; 97 (7): 889-901

    Abstract

    S100/calgranulin polypeptides are present at sites of inflammation, likely released by inflammatory cells targeted to such loci by a range of environmental cues. We report here that receptor for AGE (RAGE) is a central cell surface receptor for EN-RAGE (extracellular newly identified RAGE-binding protein) and related members of the S100/calgranulin superfamily. Interaction of EN-RAGEs with cellular RAGE on endothelium, mononuclear phagocytes, and lymphocytes triggers cellular activation, with generation of key proinflammatory mediators. Blockade of EN-RAGE/RAGE quenches delayed-type hypersensitivity and inflammatory colitis in murine models by arresting activation of central signaling pathways and expression of inflammatory gene mediators. These data highlight a novel paradigm in inflammation and identify roles for EN-RAGEs and RAGE in chronic cellular activation and tissue injury.

    View details for Web of Science ID 000081162800010

    View details for PubMedID 10399917

  • Heavy chain deposition disease: The disease spectrum AMERICAN JOURNAL OF KIDNEY DISEASES Kambham, N., Markowitz, G. S., Appel, G. B., Kleiner, M. J., Aucouturier, P., D'Agati, V. D. 1999; 33 (5): 954-962

    Abstract

    A 45-year-old white woman was found to have microscopic hematuria during her annual physical examination. After a negative urologic workup, she returned 5 months later with nephrotic syndrome, renal insufficiency, and hypocomplementemia. Renal biopsy showed a nodular sclerosing glomerulopathy that could not be further characterized because of inadequate tissue for immunofluorescence. The patient returned 8 months later with chronic renal failure. A repeat renal biopsy showed deposits composed of immunoglobulin G (IgG) heavy chain and complement components C3 and C1 along glomerular, tubular, and vascular basement membranes, with negativity for kappa and lambda light chains, findings consistent with heavy chain deposition disease (HCDD). The heavy chain subclass was exclusively IgG3. Staining with monoclonal antibodies to epitopes of the constant domains of IgG heavy chain showed a CH1 deletion, indicating a truncated heavy chain. On review of the previously reported cases of HCDD, common clinical presentations include nephrotic syndrome, renal insufficiency, hematuria, and, in some cases, hypocomplementemia. In most patients, the hematologic disorder is mild, without overt myeloma. Light microscopy shows a nodular sclerosing glomerulopathy, and heavy chain deposits are detectable within basement membranes throughout the kidney by immunofluorescence and electron microscopy. There is no effective treatment for this condition, and virtually all patients progress to chronic renal failure.

    View details for Web of Science ID 000079919900021

    View details for PubMedID 10213655

  • Recurrence of gynecologic malignancy at the vaginal vault after hysterectomy INTERNATIONAL JOURNAL OF GYNECOLOGY & OBSTETRICS Heller, D. S., Kambham, N., Smith, D., Cracchiolo, B. 1999; 64 (2): 159-162

    Abstract

    Vaginal vault recurrences of genital tract malignancy are not uncommon, and may be the first sign of recurrent disease. This paper reviews the experience at Columbia Presbyterian Medical Center.The tumor lists from 1993 to 1996 of the Division of Ob/Gyn Pathology at Columbia Presbyterian Medical Center were reviewed, and correlated with retrospective chart review.Of 36 cases, 13 were from uterine primaries, seven were cervical in origin, eight were ovarian primaries, and in eight cases, the exact primary was not known at the time of biopsy. For the cases where the primary diagnosis and disease free interval were known, the time interval from hysterectomy to vault recurrence ranged from 1.5 months to 84 months, with a mean of 25.6 months.Vaginal vault recurrences are often the site of recurrent female genital tract malignancies. Patients treated for gynecological cancer must have regular pelvic examinations including cytologic examination as part of their oncologic surveillance.

    View details for Web of Science ID 000078736700009

    View details for PubMedID 10189025

  • Atypical small acinar proliferation in prostate needle biopsies J Urol Pathol Kambham N, Taylor JA, Troxel A, Rubin MA 1999; 10: 177
  • Primary low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) arising in dura CLINICAL NEUROPATHOLOGY Kambham, N., Chang, Y., Matsushima, A. Y. 1998; 17 (6): 311-317

    Abstract

    We report 2 cases of low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type presenting as primary lesions in the intracranial dura. Both patients are female, and, prior to biopsy were felt to have subdural hematoma and meningioma based on preoperative MRI scans. Histologically, both cases showed a diffuse proliferation of small centrocyte-like cells or monocytoid B cells admixed with a moderate number of large transformed cells. Reactive germinal center formation was present, as was plasmacytoid differentiation in one case. These histologic features are identical to those associated with low-grade MALT lymphomas arising at other more typical sites. Clinically, both patients were found to have stage IE disease at diagnosis without evidence of lymphoma outside of the central nervous system. Immunophenotypically, the lymphomas expressed B-cell-associated antigens CD20 and CD79a without coexpression of CD5, CD10, or CD23, and 1 of the 2 cases tested showed monoclonal rearrangement of the immunoglobulin heavy chain gene without rearrangement of bcl-1 or bcl-2. MALT lymphomas have recently been described in the dura and are postulated to arise in association with meningoepithelial cells. It is important that this entity be recognized and distinguished from other small B-cell non-Hodgkin's lymphomas such as mantle cell lymphoma, small lymphocytic lymphoma, or follicular small cleaved cell lymphomas, since localized low grade MALT lymphomas are usually clinically indolent proliferations which may require only minimally aggressive therapy.

    View details for Web of Science ID 000076821500004

    View details for PubMedID 9832258

  • Incidental finding of Zygomyceteslike hyphae in the placenta - A case report JOURNAL OF REPRODUCTIVE MEDICINE Kambham, N., Heller, D. S., Weitzman, I. 1998; 43 (3): 230-232

    Abstract

    Zygomycetes is a class of saprophytic fungi causing opportunistic infections. These fungi can cause six distinct clinical manifestations, which can be fatal without rapid diagnosis and treatment. The fungi have a predilection for blood vessel invasion, causing thrombosis, infarction and necrosis of the tissue.A 25-year-old black woman, a drug abuser, delivered a female infant and the placenta en route to the hospital. The estimated gestational age of the infant was 35 weeks. The infant and mother had an unremarkable hospital course. Evaluation of the placenta revealed extensive involvement of the membranes, umbilical cord and chorionic plate by fungal hyphae without any surrounding inflammation. These hyphae were seen invading blood vessels, but there was no evidence of thrombosis or necrosis. The morphology of the hyphae was consistent with Zygomycetes. The mother was contacted and claimed to be well.Only one case of placental involvement by Mucor has been published since 1966. Despite the observation of Zygomyceteslike hyphae in the placenta, both the mother and infant were reported to be doing well.

    View details for Web of Science ID 000072958700016

    View details for PubMedID 9564653

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