Biography
In addition to caring for patients, Posselt conducts research on pancreatic islet cell transplantation, a procedure that can allow people with type 1 diabetes to discontinue insulin therapy. He also investigates mechanisms by which a transplant recipient's body rejects or tolerates tissue from a donor who isn't genetically identical, and he studies the metabolic and biochemical consequences of bariatric surgery.
Posselt earned his medical degree and a doctorate in immunology from the University of Pennsylvania. He completed residencies in internal medicine and general surgery as well as a transplant fellowship at UCSF, before joining the staff in 2003.
Posselt is a member of several professional and honorary societies, and has given presentations on transplant issues related to patient care and research. At UCSF, he supervises residents and fellows in transplant services and general surgery.
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Education
Institution | Degree | Dept or School | End Date |
---|---|---|---|
University of Pennsylvania | PhD | Immunology | 1993 |
University of Pennsylvania | M.D. | School of Medicine | 1993 |
University of California, San Francisco | Residency | Internal Medicine |
Board Certifications
- American Board of Internal Medicine, 1996
- American Board of Surgery, 2002
Clinical Expertise
Bariatric Surgery (Laparoscopic and Open)
Bile Duct Injuries
Bile Duct Strictures
Choledochal Cyst Disease
End-Stage Kidney Disease
Fulminant Hepatic Failure
Hepatitis B
Hepatitis C
Hepatocellular Carcinoma (Primary Liver Cancer)
Kidney Transplantation
Laparoscopic Donor Nephrectomy
Liver Cysts
Liver Transplantation
Nonalcoholic Fatty Liver Disease
Pancreas Transplantation
Pediatric Liver Transplantation
Pediatric Kidney Transplantation
Portal Hypertension
Islet Cell Transplantation
Autologous Islet Cell Transplantation
Program Affiliations
Pancreatic Islet Transplantation Program
Bariatric Surgery Center
ABO-Incompatible Kidney Transplant Program
In the News
Grants and Funding
- Vertical Sleeve Gastrectomy for Treatment of NASH: a pilot randomized control | NIH | 2021-07-14 - 2024-05-31 | Role: Co-Principal Investigator
- Treatment of Type I Diabetes by Islet Transplantation into the Gastric Submucosa | NIH | 2014-05-01 - 2021-04-30 | Role: Principal Investigator
- "Advancing Islet Transplant for Type 1 Diabetes Care" | NIH | 2009-09-30 - 2013-07-31 | Role: Principal Investigator
- Effect of Obesity on Long-Term Clinical Outcomes after Kidney Donation | NIH | 2009-09-21 - 2012-06-30 | Role: Principal Investigator
Research Interests
- Transplantation of pancreatic islets as treatment for type 1 diabetes mellitus
- Assessment of long-term clinical outcomes in kidney donors
- Metabolic and biochemical consequences of bariatric surgery
- Clinical outcomes of bariatric surgery in patients with end-stage kidney or liver disease
Publications
- Skeletal effects of sleeve gastrectomy, by sex and menopausal status and compared to Roux-en-Y gastric bypass surgery.| | PubMed
- Islet Isolation Outcomes in Patients Undergoing Total Pancreatectomy With Islet Autotransplantation in the POST Consortium.| | PubMed
- Skeletal effects of sleeve gastrectomy, by sex and menopausal status and in comparison to Roux-en-Y gastric bypass surgery.| | PubMed
- Alteration in the gut microbiome is associated with changes in bone metabolism after laparoscopic sleeve gastrectomy.| | PubMed
- Nutritional Risks in Patients Undergoing Total Pancreatectomy Islet AutoTransplantation in the POST Consortium.| | PubMed
- A Multi-Modal Approach to Islet and Pancreas Transplantation With Calcineurin-Sparing Immunosuppression Maintains Long-Term Insulin Independence in Patients With Type I Diabetes.| | PubMed
- Intestinal Calcium Absorption Decreases After Laparoscopic Sleeve Gastrectomy Despite Optimization of Vitamin D Status.| | PubMed
- Characterization of human islet function in a convection-driven intravascular bioartificial pancreas.| | PubMed
- Prebiotic to Improve Calcium Absorption in Postmenopausal Women After Gastric Bypass: A Randomized Controlled Trial.| | PubMed
- Islets Transplantation at a Crossroads - Need for Urgent Regulatory Update in the United States: Perspective Presented During the Scientific Sessions 2021 at the American Diabetes Association Congress.| | PubMed
- Advantages and Limitations of Clinical Scores for Donation After Circulatory Death Liver Transplantation.| | PubMed
- Surgical approach and short-term outcomes in adults and children undergoing total pancreatectomy with islet autotransplantation: A report from the Prospective Observational Study of TPIAT.| | PubMed
- Bariatric surgery prior to transplantation and risk of early hospital re-admission, graft failure, or death following kidney transplantation.| | PubMed
- The Association of Smoking and Alcohol Abuse on Anxiety and Depression in Patients With Recurrent Acute or Chronic Pancreatitis Undergoing Total Pancreatectomy and Islet Autotransplantation: A Report From the Prospective Observational Study of TPIAT Cohor| | PubMed
- Arguments against the Requirement of a Biological License Application for Human Pancreatic Islets: The Position Statement of the Islets for US Collaborative Presented during the FDA Advisory Committee Meeting.| | PubMed
- Targeting CXCR1/2 in the first multicenter, double-blinded, randomized trial in autologous islet transplant recipients.| | PubMed
- Sleeve gastrectomy prior to liver transplantation is superior to medical weight loss in reducing posttransplant metabolic complications.| | PubMed
- Anticoagulation practices in total pancreatectomy with autologous islet cell transplant patients: an international survey of clinical programs.| | PubMed
- Circulating miRNA in Patients Undergoing Total Pancreatectomy and Islet Autotransplantation.| | PubMed
- Preoperative ERCP has no impact on islet yield following total pancreatectomy and islet autotransplantation (TPIAT): Results from the Prospective Observational Study of TPIAT (POST) cohort.| | PubMed
- COVID-19 and Abdominal Transplant: A Stepwise Approach to Practice During Pandemic Conditions.| | PubMed
- Phase 3 trial of human islet-after-kidney transplantation in type 1 diabetes.| | PubMed
- Ampullary stenosis and choledocholithiasis post Roux-En-Y gastric bypass: challenges of biliary access and intervention.| | PubMed
- Long-term follow-up of beta cell replacement therapy in 10 HIV-infected patients with renal failure secondary to type 1 diabetes mellitus.| | PubMed
- Obesity, transplantation, and bariatric surgery: An evolving solution for a growing epidemic.| | PubMed
- Increases in PYY and uncoupling of bone turnover are associated with loss of bone mass after gastric bypass surgery.| | PubMed
- A Study on the Effect of Patient Characteristics, Geographical Utilization, and Patient Outcomes for Total Pancreatectomy Alone and Total Pancreatectomy With Islet Autotransplantation in Patients With Pancreatitis in the United States.| | PubMed
- Outcomes of Sleeve Gastrectomy in Obese Liver Transplant Candidates.| | PubMed
- Changes in Lean Mass, Absolute and Relative Muscle Strength, and Physical Performance After Gastric Bypass Surgery.| | PubMed
- Oxygen Perfusion (Persufflation) of Human Pancreata Enhances Insulin Secretion and Attenuates Islet Proinflammatory Signaling.| | PubMed
- Effects of Gastric Bypass Surgery on Bone Mass and Microarchitecture Occur Early and Particularly Impact Postmenopausal Women.| | PubMed
- Splenic Vein Thrombosis Following Pancreas Transplantation: Identification of Factors That Support Conservative Management.| | PubMed
- Bone Marrow Fat Changes After Gastric Bypass Surgery Are Associated With Loss of Bone Mass.| | PubMed
- Erratum. National Institutes of Health-Sponsored Clinical Islet Transplantation Consortium Phase 3 Trial: Manufacture of a Complex Cellular Product at Eight Processing Facilities. Diabetes 2016;65:3418-3428.| | PubMed
- Correction: An intravascular bioartificial pancreas device (iBAP) with silicon nanopore membranes (SNM) for islet encapsulation under convective mass transport.| | PubMed
- Pancreas-After-Islet Transplantation in Nonuremic Type 1 Diabetes: A Strategy for Restoring Durable Insulin Independence.| | PubMed
- Purified Human Pancreatic Islets, CIT Culture Media with Lisofylline or Exenatide.| | PubMed
- An intravascular bioartificial pancreas device (iBAP) with silicon nanopore membranes (SNM) for islet encapsulation under convective mass transport.| | PubMed
- Glucose-Stimulated Insulin Response of Silicon Nanopore-Immunoprotected Islets under Convective Transport.| | PubMed
- A Single Perioperative Injection of Dexamethasone Decreases Nausea, Vomiting, and Pain after Laparoscopic Donor Nephrectomy.| | PubMed
- National Institutes of Health-Sponsored Clinical Islet Transplantation Consortium Phase 3 Trial: Manufacture of a Complex Cellular Product at Eight Processing Facilities.| | PubMed
- Abnormalities in biomarkers of mineral and bone metabolism in kidney donors.| | PubMed
- Phase 3 Trial of Transplantation of Human Islets in Type 1 Diabetes Complicated by Severe Hypoglycemia.| | PubMed
- Silicon nanopore membrane (SNM) for islet encapsulation and immunoisolation under convective transport.| | PubMed
- Effect of Immigration Status on Outcomes in Pediatric Kidney Transplant Recipients.| | PubMed
- A Multicenter Study: North American Islet Donor Score in Donor Pancreas Selection for Human Islet Isolation for Transplantation.| | PubMed
- Under Utilization of Pancreas Transplants in Cystic Fibrosis Recipients in the United Network Organ Sharing (UNOS) Data 1987-2014.| | PubMed
- A Comparative Analysis of the Safety, Efficacy, and Cost of Islet Versus Pancreas Transplantation in Nonuremic Patients With Type 1 Diabetes.| | PubMed
- Expanded indications for bariatric surgery: should patients on chronic steroids be offered bariatric procedures?| | PubMed
- Intestinal Calcium Absorption Decreases Dramatically After Gastric Bypass Surgery Despite Optimization of Vitamin D Status.| | PubMed
- Autologous islet transplantation with remote islet isolation after pancreas resection for chronic pancreatitis.| | PubMed
- Changes in vertebral bone marrow fat and bone mass after gastric bypass surgery: A pilot study.| | PubMed
- Islet transplantation for Type 1 diabetes: where are we now?| | PubMed
- Islet product characteristics and factors related to successful human islet transplantation from the Collaborative Islet Transplant Registry (CITR) 1999-2010.| | PubMed
- Human islet viability and function is maintained during high-density shipment in silicone rubber membrane vessels.| | PubMed
- Predictors of hospital stay following laparoscopic gastric bypass: analysis of 9,593 patients from the National Surgical Quality Improvement Program.| | PubMed
- Combined pancreatic islet and kidney transplantation in a child with unstable type 1 diabetes and end-stage renal disease.| | PubMed
- Laparoscopic sleeve gastrectomy is safe and efficacious for pretransplant candidates.| | PubMed
- Improvement in outcomes of clinical islet transplantation: 1999-2010.| | PubMed
- Safety and feasibility of sleeve gastrectomy in morbidly obese patients following liver transplantation.| | PubMed
- Islet Transplantation & β-Cell Replacement Therapies for Diabetes.| | PubMed
- Experience with laparoscopic donor nephrectomy among more than 1000 cases: low complication rates, despite more challenging cases.| | PubMed
- Early and late abdominal bleeding after Roux-en-Y gastric bypass: sources and tailored therapeutic strategies.| | PubMed
- Islet transplantation in type 1 diabetic patients using calcineurin inhibitor-free immunosuppressive protocols based on T-cell adhesion or costimulation blockade.| | PubMed
- Islet transplantation in type 1 diabetics using an immunosuppressive protocol based on the anti-LFA-1 antibody efalizumab.| | PubMed
- Clinical islet transplantation at the University of California, San Francisco.| | PubMed
- Successful clinical islet isolation using a GMP-manufactured collagenase and neutral protease.| | PubMed
- Portomesenteric venous thrombosis after laparoscopic surgery: a systematic literature review.| | PubMed
- Long-term renal function and cardiovascular disease risk in obese kidney donors.| | PubMed
- Factors associated with weight loss after gastric bypass.| | PubMed
- A clinical scoring system for predicting nonalcoholic steatohepatitis in morbidly obese patients.| | PubMed
- Laparoscopic bariatric surgery improves candidacy in morbidly obese patients awaiting transplantation.| | PubMed
- Human albumin preserves islet mass and function better than whole serum during pretransplantation islet culture.| | PubMed
- The impact of roux limb length on weight loss after gastric bypass.| | PubMed
- Catheter-directed therapy for DVT after pancreas transplantation.| | PubMed
- Spectrum and risk factors of complications after gastric bypass.| | PubMed
- Predictors, treatment, and outcomes of gastrojejunostomy stricture after gastric bypass for morbid obesity.| | PubMed
- Routine upper GI series after gastric bypass does not reliably identify anastomotic leaks or predict stricture formation.| | PubMed
- Propylthiouracil-associated liver failure presenting as probable autoimmune hepatitis in a child with Graves' disease.| | PubMed
- Antibody-mediated rejection of a pancreas allograft.| | PubMed
- Pretransplant islet culture: a comparison of four serum-free media using a murine model of islet transplantation.| | PubMed
- More than 500 consecutive laparoscopic donor nephrectomies without conversion or repeated surgery.| | PubMed
- Laparoscopic procurement of kidneys with multiple renal arteries is associated with increased ureteral complications in the recipient.| | PubMed
- BKV in simultaneous pancreas-kidney transplant recipients: a leading cause of renal graft loss in first 2 years post-transplant.| | PubMed
- Laparoscopic right donor nephrectomy: a large single-center experience.| | PubMed
- Experience with steroid-free maintenance immunosuppression in simultaneous pancreas-kidney transplantation.| | PubMed
- Congenital cleft spleen with CT scan appearance of high-grade splenic laceration after blunt abdominal trauma.| | PubMed
- CD69 expression on peripheral CD8 T cells correlates with acute rejection in renal transplant recipients.| | PubMed
- Longevity of 2328 chairside Cerec inlays and onlays.| | PubMed
- Intraportal delivery of immunosuppression to intrahepatic islet allograft recipients.| | PubMed
- Prolongation of survival of donor-strain islet xenografts (rat-->mouse) by intrathymic inoculation of xenogeneic islet and bone marrow cells.| | PubMed
- Intrathymic transplantation promotes survival of islet xenografts (rat-->mouse).| | PubMed
- The failure of intrathymic transplantation of nonimmunogenic islet allografts to promote induction of donor-specific unresponsiveness.| | PubMed
- Examination of the mechanisms responsible for tolerance induction after intrathymic inoculation of allogeneic bone marrow.| | PubMed
- Promotion of rat cardiac allograft survival by intrathymic inoculation of donor splenocytes.| | PubMed
- Prolonged survival of rat orthotopic liver allografts after intrathymic inoculation of donor-strain cells.| | PubMed
- Intrathymic inoculation of donor cells promotes survival of rat orthotopic liver allografts.| | PubMed
- Intrathymic inoculation of islets at birth prevents autoimmune diabetes and pancreatic insulitis in the BB rat.| | PubMed
- Prolonged survival of rat cardiac allografts after intrathymic inoculation of donor thymocytes.| | PubMed
- Intrathymic transplantation as a model for tolerance.| | PubMed
- Prolongation of rat pancreatic islet allograft survival by anti-CD2 monoclonal antibody treatment.| | PubMed
- Pioneering work in immune tolerance.| | PubMed
- Microchimerism of the thymus and graft acceptance.| | PubMed
- Induction of donor-specific tolerance to rat cardiac allografts by intrathymic inoculation of bone marrow.| | PubMed
- Promotion of pancreatic islet allograft survival by intrathymic transplantation of bone marrow.| | PubMed
- Successful islet transplantation in the thymus of spontaneously diabetic BB rats.| | PubMed
- Prevention of autoimmune diabetes in the BB rat by intrathymic islet transplantation at birth.| | PubMed
- Intraportal FK 506 improves intrahepatic islet allograft survival.| | PubMed
- Intrathymic islet transplantation in the spontaneously diabetic BB rat.| | PubMed
- Major-histocompatibility-complex restricted and nonrestricted autoimmune effector mechanisms in BB rats.| | PubMed
- Studies of privileged sites and islet transplantation.| | PubMed
- Selective T-cell depletion of recipients in allogeneic small bowel transplantation (SBT) in the rat.| | PubMed
- Induction of donor-specific unresponsiveness by intrathymic islet transplantation.| | PubMed
- Immunologic consequences of islet MHC antigen modulation in autoimmune diabetes.| | PubMed
- The effect of islet cell culture in vitro at 24 degrees C on graft survival and MHC antigen expression.| | PubMed
- Suppression of carbon monoxide excretion rate by tin protoporphyrin.| | PubMed
- Effect of tin protoporphyrin on the excretion rate of carbon monoxide in newborn rats after hematoma formation.| | PubMed