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Dive into the research topics where Peter G. Stock is active.

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Featured researches published by Peter G. Stock.


Diabetes Care | 2012

Improvement in Outcomes of Clinical Islet Transplantation: 1999–2010

Franca B. Barton; Michael R. Rickels; Rodolfo Alejandro; Bernhard J. Hering; Stephen Wease; Bashoo Naziruddin; José Oberholzer; Jon S. Odorico; Marc R. Garfinkel; Marlon F. Levy; François Pattou; Thierry Berney; Antonio Secchi; Shari Messinger; Peter A. Senior; Paola Maffi; Andrew M. Posselt; Peter G. Stock; Dixon B. Kaufman; Xunrong Luo; Fouad Kandeel; Enrico Cagliero; Nicole A. Turgeon; Piotr Witkowski; Ali Naji; Philip J. O'Connell; Carla J. Greenbaum; Yogish C. Kudva; Kenneth L. Brayman; Meredith J. Aull

OBJECTIVE To describe trends of primary efficacy and safety outcomes of islet transplantation in type 1 diabetes recipients with severe hypoglycemia from the Collaborative Islet Transplant Registry (CITR) from 1999 to 2010. RESEARCH DESIGN AND METHODS A total of 677 islet transplant-alone or islet-after-kidney recipients with type 1 diabetes in the CITR were analyzed for five primary efficacy outcomes and overall safety to identify any differences by early (1999–2002), mid (2003–2006), or recent (2007–2010) transplant era based on annual follow-up to 5 years. RESULTS Insulin independence at 3 years after transplant improved from 27% in the early era (1999–2002, n = 214) to 37% in the mid (2003–2006, n = 255) and to 44% in the most recent era (2007–2010, n = 208; P = 0.006 for years-by-era; P = 0.01 for era alone). C-peptide ≥0.3 ng/mL, indicative of islet graft function, was retained longer in the most recent era (P < 0.001). Reduction of HbA1c and resolution of severe hypoglycemia exhibited enduring long-term effects. Fasting blood glucose stabilization also showed improvements in the most recent era. There were also modest reductions in the occurrence of adverse events. The islet reinfusion rate was lower: 48% by 1 year in 2007–2010 vs. 60–65% in 1999–2006 (P < 0.01). Recipients that ever achieved insulin-independence experienced longer duration of islet graft function (P < 0.001). CONCLUSIONS The CITR shows improvement in primary efficacy and safety outcomes of islet transplantation in recipients who received transplants in 2007–2010 compared with those in 1999–2006, with fewer islet infusions and adverse events per recipient.


Transplantation | 1995

The risk of transmission of hepatitis B from HBsAg(-), HBcAb(+), HBIgM(-) organ donors.

Michael Wachs; William Amend; Nancy L. Ascher; Peter N. Bretan; Jean C. Emond; John R. Lake; Juliet S. Melzer; John P. Roberts; S. Tomlanovich; Flavio Vincenti; Peter G. Stock

Liver allografts from HBcAb(+), IgM(-), HBsAg(-) donors can transmit HBV to uninfected recipients. We currently no longer accept these livers for transplantation while continuing to accept the kidneys. The purpose of this study is to determine the risk of donor-transmitted HBV infections from HBcAb(+), HBIgM(-), HBsAg(-) organ donors and determine if the risk of donor-transmitted HBV infections and their severity is dependent on the organ being transplanted. This study consists of a retrospective review of the posttransplant course of recipients of HBcAb(+), HBIgM(-), HBsAg(-) donors accepted at UCSF from 6/85 to 12/93. Transmitted HBV infection was defined as one in which the recipient changed from HBsAg(-) prior to transplantation to HBsAg(+) posttransplant, with no other source. There were 25 of 1190 donors who were HBcAb(+), HBIgM(-), HBsAg(-); 1/42 kidney, 3/6 liver, and 0/7 heart HBsAg(-) transplant recipients of organs from these donors became HBsAg(+) after transplantation. This difference in infection rate (liver vs. kidney and heart) is statistically significant. The clinical course of the liver recipients was also more severe. All of the patients who became infected were HBsAb(-) and HBcAb(-) prior to transplant. We conclude that (1) HBV can be transmitted from HBcAb(+), HBIgM(-), HBsAg(-) organ donors, (2) the rate of transmission is highest and severity of infection is worst in the liver recipients; and (3) we will continue to transplant kidneys from these donors, preferably into immunized recipients.


The New England Journal of Medicine | 2010

Outcomes of Kidney Transplantation in HIV-Infected Recipients

Peter G. Stock; Burc Barin; Barbara Murphy; Douglas W. Hanto; Jorge Diego; Jimmy A. Light; Charles E. L. B. Davis; Emily A. Blumberg; David K. Simon; Aruna K. Subramanian; J. Michael Millis; G. Marshall Lyon; Kenneth L. Brayman; Doug Slakey; Ron Shapiro; Joseph K. Melancon; Jeffrey M. Jacobson; Valentina Stosor; Jean L. Olson; Donald Stablein; Michelle E. Roland

BACKGROUND The outcomes of kidney transplantation and immunosuppression in people infected with human immunodeficiency virus (HIV) are incompletely understood. METHODS We undertook a prospective, nonrandomized trial of kidney transplantation in HIV-infected candidates who had CD4+ T-cell counts of at least 200 per cubic millimeter and undetectable plasma HIV type 1 (HIV-1) RNA levels while being treated with a stable antiretroviral regimen. Post-transplantation management was provided in accordance with study protocols that defined prophylaxis against opportunistic infection, indications for biopsy, and acceptable approaches to immunosuppression, management of rejection, and antiretroviral therapy. RESULTS Between November 2003 and June 2009, a total of 150 patients underwent kidney transplantation; survivors were followed for a median period of 1.7 years. Patient survival rates (±SD) at 1 year and 3 years were 94.6±2.0% and 88.2±3.8%, respectively, and the corresponding mean graft-survival rates were 90.4% and 73.7%. In general, these rates fall somewhere between those reported in the national database for older kidney-transplant recipients (≥65 years) and those reported for all kidney-transplant recipients. A multivariate proportional-hazards analysis showed that the risk of graft loss was increased among patients treated for rejection (hazard ratio, 2.8; 95% confidence interval [CI], 1.2 to 6.6; P=0.02) and those receiving antithymocyte globulin induction therapy (hazard ratio, 2.5; 95% CI, 1.1 to 5.6; P=0.03); living-donor transplants were protective (hazard ratio, 0.2; 95% CI, 0.04 to 0.8; P=0.02). A higher-than-expected rejection rate was observed, with 1-year and 3-year estimates of 31% (95% CI, 24 to 40) and 41% (95% CI, 32 to 52), respectively. HIV infection remained well controlled, with stable CD4+ T-cell counts and few HIV-associated complications. CONCLUSIONS In this cohort of carefully selected HIV-infected patients, both patient- and graft-survival rates were high at 1 and 3 years, with no increases in complications associated with HIV infection. The unexpectedly high rejection rates are of serious concern and indicate the need for better immunotherapy. (Funded by the National Institute of Allergy and Infectious Diseases; ClinicalTrials.gov number, NCT00074386.).


American Journal of Transplantation | 2008

HIV-infected liver and kidney transplant recipients: 1- and 3-year outcomes.

Michelle E. Roland; Burc Barin; Laurie Carlson; Lynda Frassetto; Norah A. Terrault; Ryutaro Hirose; Chris E. Freise; Leslie Z. Benet; Nancy L. Ascher; John P. Roberts; Barbara Murphy; M. J. Keller; Kim M. Olthoff; Emily A. Blumberg; Kenneth L. Brayman; S. T. Bartlett; Charles E. L. B. Davis; J. M. McCune; B. M. Bredt; Donald Stablein; Peter G. Stock

Improvements in human immunodeficiency virus (HIV)‐associated mortality make it difficult to deny transplantation based upon futility. Outcomes in the current management era are unknown. This is a prospective series of liver or kidney transplant recipients with stable HIV disease. Eleven liver and 18 kidney transplant recipients were followed for a median of 3.4 years (IQR [interquartile range] 2.9–4.9). One‐ and 3‐year liver recipients’ survival was 91% and 64%, respectively; kidney recipients’ survival was 94%. One‐ and 3‐year liver graft survival was 82% and 64%, respectively; kidney graft survival was 83%. Kidney patient and graft survival were similar to the general transplant population, while liver survival was similar to the older population, based on 1999–2004 transplants in the national database. CD4+ T‐cell counts and HIV RNA levels were stable; and there were two opportunistic infections (OI). The 1‐ and 3‐year cumulative incidence (95% confidence intervals [CI]) of rejection episodes for kidney recipients was 52% (28–75%) and 70% (48–92%), respectively. Two‐thirds of hepatitis C virus (HCV)‐infected patients, but no patient with hepatitis B virus (HBV) infection, recurred. Good transplant and HIV‐related outcomes among kidney transplant recipients, and reasonable outcomes among liver recipients suggest that transplantation is an option for selected HIV‐infected patients cared for at centers with adequate expertise.


Transplantation | 2003

Kidney and liver transplantation in human immunodeficiency virus-infected patients: a pilot safety and efficacy study.

Peter G. Stock; Michelle E. Roland; Laurie Carlson; Chris E. Freise; John P. Roberts; Ryutaro Hirose; Norah A. Terrault; Lynda Frassetto; Joel M. Palefsky; Stephen J. Tomlanovich; Nancy L. Ascher

Background. Human immunodeficiency virus (HIV)-infected patients have historically been excluded from consideration for transplantation out of concern for the effects of immunosuppression on the progression of HIV disease. Improvements in HIV-related morbidity and mortality with the use of highly active antiretroviral therapy (HAART) have prompted a reevaluation of transplantation as a treatment option for HIV-infected patients with end-stage kidney and liver disease. Methods. Eligible patients met standard transplant criteria. They had undetectable plasma HIV-1 RNA levels (viral load) for 3 months (kidney) or were predicted to achieve viral load suppression posttransplantation if unable to tolerate HAART (liver); a CD4+ T-cell count of more than 200 cells/&mgr;L (kidney) or more than 100 cells/&mgr;L (liver) for 6 months; and no history of opportunistic infections and neoplasm. Standard immunosuppression included prednisone, mycophenolate mofetil (CellCept, Roche Pharmaceuticals, Basel, Switzerland), and cyclosporine (Neoral, Novartis, East Hanover, NJ). Results. Fourteen patients received transplants (10 kidney transplants, mean follow-up 480 days; four liver transplants, mean follow-up 380 days). All of the kidney transplant recipients (100%) are alive and with functioning grafts, and three of four liver transplant patients (75%) are alive and well with functioning grafts (all liver transplant patients with normal liver function tests). The one death occurred 445 days posttransplantation in a liver recipient coinfected with hepatitis C virus, who died as the result of its rapid reoccurrence. Rejection occurred in 5 of 10 kidney transplant recipients but did not occur in any of the four liver transplant recipients. HIV viral loads have remained undetectable in all patients maintained with HAART. CD4 counts have remained stable in patients not treated for rejection. Patients receiving protease inhibitors require 25% of the dose of cyclosporine compared with patients receiving nonnucleoside reverse transcriptase inhibitors. Conclusions. There has been no evidence of significant HIV progression and no adverse effect of HIV on allograft function. Rejection is a concern in kidney transplant recipients, as is the possible poor outcome in hepatitis C virus-coinfected liver transplant recipients. Preliminary data are encouraging and indicate that transplantation should be a treatment option for individuals with well-controlled HIV disease.


Liver Transplantation | 2012

Outcomes of liver transplant recipients with hepatitis C and human immunodeficiency virus coinfection

Norah A. Terrault; Michelle E. Roland; Thomas D. Schiano; Lorna Dove; Michael T. Wong; Fred Poordad; Margaret V. Ragni; Burc Barin; David K. Simon; Kim M. Olthoff; Lynt B. Johnson; Valentina Stosor; Dushyantha Jayaweera; John J. Fung; Kenneth E. Sherman; Aruna K. Subramanian; J. Michael Millis; Douglas P. Slakey; Carl L. Berg; Laurie Carlson; Linda D. Ferrell; Donald Stablein; Jonah Odim; Lawrence Fox; Peter G. Stock

Hepatitis C virus (HCV) is a controversial indication for liver transplantation (LT) in human immunodeficiency virus (HIV)–infected patients because of reportedly poor outcomes. This prospective, multicenter US cohort study compared patient and graft survival for 89 HCV/HIV‐coinfected patients and 2 control groups: 235 HCV‐monoinfected LT controls and all US transplant recipients who were 65 years old or older. The 3‐year patient and graft survival rates were 60% [95% confidence interval (CI) = 47%‐71%] and 53% (95% CI = 40%‐64%) for the HCV/HIV patients and 79% (95% CI = 72%‐84%) and 74% (95% CI = 66%‐79%) for the HCV‐infected recipients (P < 0.001 for both), and HIV infection was the only factor significantly associated with reduced patient and graft survival. Among the HCV/HIV patients, older donor age [hazard ratio (HR) = 1.3 per decade], combined kidney‐liver transplantation (HR = 3.8), an anti‐HCV–positive donor (HR = 2.5), and a body mass index < 21 kg/m2 (HR = 3.2) were independent predictors of graft loss. For the patients without the last 3 factors, the patient and graft survival rates were similar to those for US LT recipients. The 3‐year incidence of treated acute rejection was 1.6‐fold higher for the HCV/HIV patients versus the HCV patients (39% versus 24%, log rank P = 0.02), but the cumulative rates of severe HCV disease at 3 years were not significantly different (29% versus 23%, P = 0.21). In conclusion, patient and graft survival rates are lower for HCV/HIV‐coinfected LT patients versus HCV‐monoinfected LT patients. Importantly, the rates of treated acute rejection (but not the rates of HCV disease severity) are significantly higher for HCV/HIV‐coinfected recipients versus HCV‐infected recipients. Our results indicate that HCV per se is not a contraindication to LT in HIV patients, but recipient and donor selection and the management of acute rejection strongly influence outcomes. Liver Transpl 18:716–726, 2012.


American Journal of Transplantation | 2007

Immunosuppressant pharmacokinetics and dosing modifications in HIV-1 infected liver and kidney transplant recipients

Lynda Frassetto; M. Browne; A. Cheng; Alan R. Wolfe; Michelle E. Roland; Peter G. Stock; Laurie Carlson; Leslie Z. Benet

Solid organ transplantation in human immunodeficiency virus (HIV)‐infected individuals requiring concomitant use of immunosuppressants (IS) (e.g. cyclosporine [CsA], sirolimus [SrL], tacrolimus [FK]) and antiretrovirals (ARVs) (e.g. protease inhibitors [PIs] and/or nonnucleoside reverse transcriptase inhibitors [NNRTIs]) is complicated by significant drug interactions. To assist in appropriate clinical management, we describe the pharmacokinetics and dosing modifications in 35 patients (20 kidney, 13 liver and two kidney‐liver HIV‐infected subjects with end‐stage kidney or liver disease), on both IS and NNRTIs, PIs, and combined NNRTIs + PIs, in studies done at weeks 2–4 and/or 12 weeks after transplantation or after a change in IS or ARV drug regimen (n = 97 studies). CsA, SrL and FK concentrations were measured in whole blood by LC/MS. HIV‐infected transplant recipients using PIs with IS had marked increases in CsA, FK or SrL trough levels compared to those on NNRTIs alone or to patients not on ARVs, necessitating either a reduction in dose or an increase in dosing interval. Subjects on efavirenz (EFV) and CsA required much higher doses of CsA than those using any other ARV. Changes in antiretroviral therapy should be carefully managed to avoid insufficient immunosuppression or toxicity due to drug interactions.


American Journal of Transplantation | 2005

Current status of kidney and pancreas transplantation in the United States, 1994-2003

Gabriel M. Danovitch; David J. Cohen; Matthew R. Weir; Peter G. Stock; William M. Bennett; Laura L. Christensen; Randall S. Sung

This article reviews the OPTN/SRTR data collected on kidney and pancreas transplantation during 2003 in the context of trends over the past decade. Overall, the transplant community continued to struggle to meet the increasing demand for kidney and pancreas transplantation. The number of new wait‐listed kidney registrants under the age of 50 has remained relatively stable since 1994, but the number of new registrants aged 50 to 64 has doubled. However, there was only a 2.3% increase in the total number of kidney transplants performed in 2003. Expanded criteria donor kidneys made up 20% of all recovered kidneys and 16% of all transplants performed, compared with 15% in the prior year. In May 2003, new rules were implemented to promote equity in kidney organ allocation. These changes seem to have improved access for historically disadvantaged groups, though they have reduced the quality of HLA matching. The effects on long‐term outcomes have yet to be measured. Although the majority of SPK recipients are white (82%), the percentage of simultaneous kidney‐pancreas recipients who are African‐American has increased from 9% in 2000 to 16% in 2003. The percentage of Hispanic/Latino recipients increased from 5% to 9% over the same period.


Transplantation | 2003

Review of solid-organ transplantation in HIV-infected patients.

Michelle E. Roland; Peter G. Stock

Patients with HIV infection are at risk for end-stage organ disease. Before the highly active antiretroviral therapy (HAART) era, such patients were often not considered for transplantation because of poor prognosis. HIV-infected patients have experienced significant improvements in morbidity and mortality with HAART (1). Thus, increasing numbers of HIV-infected patients with end-stage organ disease are potential candidates for transplantation (2). Data on the safety and efficacy of solid-organ transplantation in people with HIV infection are limited, and the results are mixed. Before the HAART era, some transplant centers reported good outcomes (3–7); other reports have been less favorable (8, 9). Encouraging preliminary data are increasingly available in the HAART era (10–12).


Clinical Infectious Diseases | 2014

Clinical Practice Guideline for the Management of Chronic Kidney Disease in Patients Infected With HIV: 2014 Update by the HIV Medicine Association of the Infectious Diseases Society of America

Gregory M. Lucas; Michael J. Ross; Peter G. Stock; Michael G. Shlipak; Christina M. Wyatt; Samir Gupta; Mohamed G. Atta; Kara Wools-Kaloustian; Paul Pham; Leslie A. Bruggeman; Jeffrey L. Lennox; Patricio E. Ray; Robert C. Kalayjian

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patients individual circumstances.

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Ryutaro Hirose

University of California

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Sang-Mo Kang

University of California

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Sandy Feng

University of California

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