Simultaneous administration of adjuvant donor bone marrow in pancreas transplant recipients

Objective The effect of donor bone marrow was evaluated for its potentially favorable effect in the authors' simultaneous pancreas/kidney transplant program. Methods From July 1994 to January 1999, 177 pancreas transplants were performed, 15 1 of which were simultaneous pancreas/kidney transplants. Ail patients rece ived tacrolimus, mycophenolate mofetil, and steroids for immunosuppression (azathioprine was used in the first year of the program). Fifty-three simul taneous pancreas/kidney transplant recipients received perioperative unmodi fied donor bone marrow, 3 to 6 x 10(8) cells/kg. Results Overall actuarial survival rates at 1 and 3 years were 98% and 95% (patient ), 95% and 87% (kidney), and 86% and 80% (pancreas), respectively. In the a djuvant bone marrow group, 1- and 3-year survival rates were 96% and 91% (p atient), 95% and 87% (kidney), and 83% and 83% (pancreas), respectively. Fo r 98 recipients who did not receive bone marrow, survival rates at 1 and 3 years were 100% and 98% (patient), 96% and 86% (kidney), and 87% and 79% (p ancreas), respectively. No pancreas allografts were lost after 3 months in bone marrow recipients, and seven in the non-bone marrow recipients were lo st to rejection at 0.7, 6.7, 8.8, 14.6, 24.1, 24.3, and 25.5 months. Twenty-two percent of bone marrow patients were steroid-free at 1 year, 45% at 2 years, and 67% at 3 years, Nineteen percent of the non-bone marrow re cipients were steroid-free at 1 year, 38% at 2 years, and 45% (p = 0.02) at 3 years. The mean acute cellular rejection rate was 0.94 +/- 1.1 in the bo ne marrow group and 1.57 +/- 1.3 (p = 0.003) in the non-bone marrow group ( includes borderline rejection and multiple rejections). The level of donor cell chimerism in the peripheral blood of bone marrow patients was at least two logs higher than in controls. Conclusion In this series, which represents the largest experience with adjuvant bone marrow infusion in pancreas recipients, there was a higher steroid withdraw al rate (p = 0.02), fewer rejection episodes, and no pancreas graft loss af ter 3 months in bone marrow recipients compared with contemporaneous contro ls. All pancreas allografts lost to chronic rejection (n = 6) were in the n on-bone marrow group. Donor bone marrow administered around the time of sur gery may have a protective effect in pancreas transplantation.