Use of FK 506 in pancreas transplantation

Until recently, FK 506 was used only for rescue therapy after pancreas transplantation. We report our initial experience with FK 506 for 67 pancreas recipients (treated between 1 May 1993 and 30 April 1995). Of these recipients, 49 (73%) received FK 506 for induction and maintenance therapy, 12 (18%) for rescue or antirejection therapy, and 6 (9%) for reasons other than rescue or antirejection therapy. In our induction and maintenance therapy group, 32 recipients (65%) underwent a simultaneous pancreas-kidney transplant (SPK), 8 (16%) a pancreas transplant alone (PTA), and 9 (19%) a pancreas after previous kidney transplant (PAK). Quadruple immunosuppression was used for induction; the median FK 506 starting dose was 4 mg/day p.o. and target levels were 10-20 ng/ml. The most common side effects were nephrotoxicity (16%) and neurotoxicity (14%); transient episodes of hyperglycemia were also noted (12%), in particular in the presence of concurrent rejection and infection episodes. A matched-pair analysis was done to compare graft outcome with FK 506 versus cyclosporin A (CsA). For SPK recipients, pancreas graft survival at 6 months was 79% with FK 506 versus 65% with CsA (P = 0.04), for PTA, 100% versus 63% (P > 0.35), and for PAK, 88% versus 33% (P > 0.01). Pancreas graft loss due to rejection at 6 months posttransplant was lower with FK 506 versus CsA. Two FK 506 recipients died from B-cell lymphomas (Epstein-Barr virus positive) at 6 and 7 months posttransplant. In our rescue or anti-rejection group, 5 recipients underwent SPK, 3 PTA, and 4 PAK. The mean average FK 506 dose was 10 mg/day p.o. and the mean average FK 506 blood level was 11 ng/ml. The most common side effects were nephrotoxicity (33%) and neurotoxicity (16%). Two recipients developed hyperglycemic episodes, of whom 1 has remained on insulin with good exocrine pancreas graft function. Graft survival at 6 months after conversion was 75% for SPK, 67% for PTA, and 50% for PAK. Only one graft was lost due to chronic rejection. Our single-center experience shows that FK 506 after pancreas transplantation is associated with: (1) a low rate of graft loss due to rejection when used for induction, in particular for solitary pancreas transplants, (2) a high rate of graft salvage when used for rescue, (3) a 1% rate of new-onset insulin-dependent diabetes mellitus, and (4) a 3% rate of posttransplant lymphoma. Further studies are necessary to analyze the long-term impact of FK 506 on pancreas transplant outcome.