Comparison of transplanted islets in patients with functioning versus nonfunctioning allografts

INCE 1985,27 transplants have occurred at Washington University School of Medicine (WUMS) in St. Louis and 4 transplants in conjunction with the University of Western Ontario, London, Ontario. The majority of suc- cessful transplants have occurred since 1989 when we entered into the era of better immunosuppression, early intensive insulin therapy, purer preparations, immunoalter- ation by 24°C culture, and cryopreservation resulting in larger transplanted islet preparations. The two groups of patients most extensively followed at WUMS were patients with established kidney grafts followed by islet transplant (EKI, n = 8) and those receiving simultaneously trans- planted kidney and islet transplant (SKI, n = 9). Several controversies concerning islet transplantation still exist. For example, should islet transplantation occur simultaneous with or following renal transplant? Does cryopreservation and/or islet culture make a difference in islet function? What is the role of human leukocyte antigen (HLA) matching? Does islet mass improve or hamper long-term islet function? Presented here are the results of a retrospec- tive study addressing these questions in regard to our EKI and SKI patients.