Bio

Clinical Focus


  • Gastroenterology/Nutrition/Hepatology, Pediatric
  • Pediatric Gastroenterology

Academic Appointments


Professional Education


  • Medical Education:Tufts University (06/97) MA
  • Residency:Mattel Children's Hospital at UCLA (06/00) CA
  • Internship:Mattel Children's Hospital at UCLA (07/98) CA
  • Fellowship:Lucile Packard Children's Hospital (06/04) CA
  • Board Certification: Pediatric Gastroenterology, American Board of Pediatrics (2007)

Teaching

2013-14 Courses


Publications

Journal Articles


  • Evaluation of ethanol lock therapy in pediatric patients on long-term parenteral nutrition. Nutrition in clinical practice Pieroni, K. P., Nespor, C., Ng, M., Garcia, M., Hurwitz, M., Berquist, W. E., Kerner, J. A. 2013; 28 (2): 226-231

    Abstract

    Pediatric home parenteral nutrition (PN) patients present a unique challenge with risks of catheter-associated bloodstream infections (CABSIs), sometimes requiring subsequent catheter removal. Recurrent infections can lead to line removal and potential loss of venous access in the future.Demonstrate that weekly ethanol lock therapy decreases CABSIs in long-term home PN patients and decreases line removals due to infections.Beginning August 2007, patients receiving PN with a history of multiple previous CABSIs were started on ethanol lock therapy. Seventy percent ethanol solution was instilled into the central venous catheter (CVC) for 2 hours weekly. Episodes of CABSIs and catheter removal due to infection were documented in patients prior to and after ethanol lock therapy.Fourteen patients were followed for an average of 690 days after ethanol lock therapy was initiated. These patients were found to average 9.8 CABSIs per 1000 catheter days prior to starting ethanol lock therapy and only 2.7 CABSIs per 1000 catheter days after ethanol lock therapy (P < .001). Prior to ethanol lock therapy, the group averaged 4.3 catheter removals per 1000 catheter days but only 1.0 catheter removal per 1000 catheter days after ethanol lock therapy.Our group of patients showed a 73% reduction in CABSIs and a 77% reduction in catheter removal due to infection after ethanol lock therapy. In our patient population, weekly ethanol lock therapy for 2 hours is an effective technique to reduce CABSIs and catheter removal in long-term home PN patients.

    View details for DOI 10.1177/0884533612468009

    View details for PubMedID 23232749

  • Intermediate-term outcomes after combined heart-liver transplantation in children with a univentricular heart JOURNAL OF HEART AND LUNG TRANSPLANTATION Hollander, S. A., Reinhartz, O., Maeda, K., Hurwitz, M., Rosenthal, D. N., Bernstein, D. 2013; 32 (3): 368-370

    Abstract

    For patients with end-stage hepatic failure secondary to failing hemodynamics, combined heart-liver transplant (H-LT) remains the only option for long-term survival. We report a series of three pediatric patients who successfully underwent orthotopic H-LT for failed single-ventricle palliation. All three patients are currently living, now two, three, and five years post-transplant, and remain completely free of cardiac cellular allograft rejection despite reduced immunosuppression protocols. One patient, however, did develop acute antibody-mediated rejection in the immediate post-transplant period, suggesting that this protective effect may be less effective in attenuating humoral mechanisms of rejection.

    View details for DOI 10.1016/j.healun.2012.11.023

    View details for Web of Science ID 000315664600014

    View details for PubMedID 23415318

  • Impact of Immunosuppression on the Development of Epstein-Barr Virus (EBV) Viremia After Pediatric Liver Transplantation TRANSPLANTATION PROCEEDINGS Lu, B. R., Park, K. T., Hurwitz, M., Cox, K. L., Berquist, W. E. 2013; 45 (1): 301-304

    Abstract

    Pediatric liver transplant (OLT) patients are at risk of posttransplant lymphoproliferative disease (PTLD) from Epstein-Barr virus (EBV). This study examined the impact of induction and immunosuppression on EBV viremia.A retrospective chart review was performed on 197 pediatric patients and induction regimen, immunosuppression levels, and EBV viremia were documented for 1 year post-OLT. Logistic regression models determined associations between induction, immunosuppression, and EBV.Fifty six percent of patients developed EBV viremia. Incidence of EBV viremia was 73% with antithymocyte globulin (ATG), 63% with daclizumab, and 39% for neither, though the trend was not significant [ATG: odds ratio (OR) 0.19; 95% confidence interval (CI) 0.024-1.58; P = .125; daclizumab OR; 1.07; 95% CI 0.270-4.23; P = .925]. Tacrolimus immunosuppression levels were supratherapeutic 28.7% of the time; however, only supratherapeutic tacrolimus levels between 0 and 2 weeks increased EBV viremia at 2 to 4 weeks post-OLT (OR 1.80; 95% CI 1.10-2.94; P = .02). Three patients developed PTLD.The use of ATG and daclizumab induction likely does not play a role in the development of EBV viremia. Supratherapeutic tacrolimus levels 0 to 2 weeks post-OLT impact the development of EBV viremia at 2 to 4 weeks. The incidence of PTLD was low, suggesting better EBV and immunosuppression monitoring plays an important role in reducing PTLD.

    View details for DOI 10.1016/j.transproceed.2012.04.035

    View details for Web of Science ID 000315007200060

    View details for PubMedID 23267800

  • Acute Liver Failure in a Pediatric Patient with Disseminated Tuberculosis DIGESTIVE DISEASES AND SCIENCES Whitney, J., Hurwitz, M., Mojtahed, A., Hwang, C., Gallo, A. 2011; 56 (10): 2780-2783

    View details for DOI 10.1007/s10620-011-1776-x

    View details for Web of Science ID 000295164600020

    View details for PubMedID 21695402

  • Analysis of clinical variables associated with tolerance in pediatric liver transplant recipients PEDIATRIC TRANSPLANTATION Talisetti, A., Hurwitz, M., Sarwal, M., Berquist, W., Castillo, R., Bass, D., Concepcion, W., Esquivel, C. O., Cox, K. 2010; 14 (8): 976-979

    Abstract

    Tolerance has been defined as stable graft function off IMS. We reviewed the data of 369 pediatric liver transplant patients to examine demographic differences that may have a PV of pediatric LT tolerance. Of the 369 patients, 280 patients were stable with detectable blood levels of IMS agents and with good graft function without biopsy proven REJ > 1 yr posttransplantation, 18 patients were noted to be TOL off IMS, 27 patients were taking MIS with drug levels below detectable range by standard laboratory parameters, and 44 patients developed one or more episodes of biopsy proven acute or chronic REJ > 1 yr post-transplantation. Variables, including percentage of biliary atresia, type of transplanted organ, history of EBV infection, patient and donor gender, and ABO blood type mismatch between recipient and donor did not have PV of tolerance. Average age in years was 1.37 ▒ 1.53 (0.3-4.9) for TOL, 1.14 ▒ 0.89 (0.4-3.1) for MIS and 3.35 ▒ 4.45 (0.3-16) for REJ. Age difference of TOL/MIS vs. REJ was significant (p =0.002) and TOL vs. REJ was significant (0.01). Age at the time of transplantation is an important predictor in the development of pediatric LT tolerance.

    View details for DOI 10.1111/j.1399-3046.2010.01360.x

    View details for Web of Science ID 000285229500007

    View details for PubMedID 21108705

  • Increased Number of Regulatory T Cells in Children With Eosinophilic Esophagitis JOURNAL OF PEDIATRIC GASTROENTEROLOGY AND NUTRITION Fuentebella, J., Patel, A., Nguyen, T., Sanjanwala, B., Berquist, W., Kerner, J. A., Bass, D., Cox, K., Hurwitz, M., Huang, J., Nguyen, C., Quiros, J. a., Nadeau, K. 2010; 51 (3): 283-289

    Abstract

    There are limited data on the role of regulatory T cells (Treg) in the disease pathology of eosinophilic esophagitis (EoE). We tested the differences in Treg in subjects with EoE compared with those with gastroesophageal reflux disease (GERD) and healthy controls (HC).Pediatric patients evaluated by endoscopy were recruited for our study. Participants were categorized into 3 groups: EoE, GERD, and HC. RNA purified from esophageal biopsies were used for real-time quantitative polymerase chain reaction assays and tested for forkhead box P3 (FoxP3) mRNA expression. Treg were identified as CD4+CD25hiCD127lo cells in peripheral blood and as CD3+/FoxP3+cells in esophageal tissue.Forty-eight subjects were analyzed by real-time quantitative polymerase chain reaction: EoE (n = 33), GERD (n = 7), and HC (n = 8). FoxP3 expression was higher by up to 1.5-fold in the EoE group compared with the GERD and HC groups (P < 0.05). Protein levels of FoxP3 in blood and tissue were then investigated in 21 subjects: EoE (n = 10), GERD (n = 6), and HC (n = 5). The percentage of Treg and their subsets in peripheral blood were not significant between groups (P > 0.05). The amount of Treg in esophageal tissue was significantly greater in the EoE group (mean 10.7 CD3+/FoxP3+cells/high power field [HPF]) compared with the other groups (GERD, mean 1.7 CD3+/FoxP3+cells/HPF and HC, mean 1.6 CD3+/FoxP3+cells/HPF) (P < 0.05).We show that Treg are increased in esophageal tissue of EoE subjects compared with GERD and HC subjects. The present study illustrates another possible mechanism involved in EoE that implicates impairment of immune homeostasis.

    View details for DOI 10.1097/MPG.0b013e3181e0817b

    View details for Web of Science ID 000281453500007

    View details for PubMedID 20639775

  • Complete immunosuppressive withdrawal as a uniform approach to post-transplant lymphoproliferative disease in pediatric liver transplantation PEDIATRIC TRANSPLANTATION Hurwitz, M., Desai, D. M., Cox, K. L., Berquist, W. E., Esquivel, C. O., Millan, M. T. 2004; 8 (3): 267-272

    Abstract

    Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disease (PTLD) in pediatric liver transplant recipients is associated with a high mortality (up to 60%) and the younger age groups, who are predominantly EBV-na´ve, are at highest risk for development of this disease. The aim of this study is to assess, in this high-risk group, patient outcome and graft loss to rejection when complete withdrawal of immunosuppressive agents (IMS) is instituted as the mainstay of treatment in addition to the use of standard therapy. A retrospective analysis of 335 pediatric patients whose liver transplants were performed by our team between September 1988 and September 2002, was carried out through review of computer records, database and patient charts. Fifty patients developed either EBV or PTLD; 80% were < or =2 yr of age. Of these 50 patients, 19 had a positive tissue diagnosis for PTLD and 31 were diagnosed with EBV infection, 14 of whom had positive tissue for EBV. Fifty-eight percent of patients who developed PTLD and 51.6% of patients with EBV received antibody for induction or treatment of rejection prior to onset of disease. Forty-six patients (92%) received post-transplant antiviral prophylaxis with ganciclovir or acyclovir. Antiviral treatment included ganciclovir in 76%, acyclovir in 20% and Cytogam (in addition to one of the former agents) in 44%. In those with PTLD, treatment included chemotherapy (n = 1), Rituximab (n = 2), and ocular radiation (n = 1). IMS was stopped in all patients with PTLD and in 19 with EBV infection and was held as long as there was no allograft rejection. Eight patients have remained off IMS for a mean of 1535.5 +/- 623 days. Of the 21 patients who were restarted on IMS for acute rejection, 18 responded to steroids and/or reinstitution of low-dose calcineurin inhibitors. The mean time to rejection while off IMS in this group was 107.43 +/- 140 days (range: 7-476). Two patients were re-transplanted for chronic rejection; one had chronic rejection that existed prior to discontinuing IMS. The mortality rate in our series was 31.6% in those with PTLD and 6% in those with EBV disease. The cause of death was related to PTLD or sepsis in all cases; no deaths were due to graft loss from acute or chronic rejection. PTLD is associated with high mortality in the pediatric population. Based on this report, we advocate aggressive management of PTLD that is composed of early cessation of IMS, the use of antiviral therapy, and chemotherapy when indicated. Episodes of rejection that occur after stopping IMS can be successfully treated with standard therapy without graft loss to acute rejection.

    View details for Web of Science ID 000221693200014

    View details for PubMedID 15176965

  • Copper deficiency during parenteral nutrition: a report of four pediatric cases. Nutrition in clinical practice Hurwitz, M., Garcia, M. G., Poole, R. L., Kerner, J. A. 2004; 19 (3): 305-308

    Abstract

    The standard of care for patients with cholestasis (direct bilirubin >or=2 mg/dL) while receiving parenteral nutrition (PN) solutions is to reduce or discontinue the copper and manganese. The repercussions of this action have not been studied. Two adult case reports document low serum copper levels associated with clinical symptoms of copper deficiency after the removal of copper from their PN solutions. We now describe the first known series of pediatric patients to develop copper deficiency after copper was removed from their PN solutions.

    View details for PubMedID 16215119

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