Initial clinical experience with interleukin-2 receptor antagonist induction in combination with tacrolimus, mycophenolate mofetil and steroids in simultaneous kidney-pancreas transplantation

Since 1996, our standard immunosuppressive protocol for simultaneous kidney-pancreas transplantation (SKPT) has been tacrolimus (TAC), mycophenolate mofetil (MMF) and steroids without antibody induction. When basiliximab and daclizumab, monoclonal antibodies directed against the interleukin-2 receptor (IL-2R), became available, we selectively added these agents to our standard protocol. The purpose of this prospective, open-label study was to evaluate the safety and efficacy of IL-2 receptor antagonists in SKPT. From April 1998 to August 1999, 35 SKPTS were performed. One patient with delayed graft function received Thymoglobulin and was excluded; 17 received no induction, and 17 received IL-2R antagonists (9 basiliximab, 8 daclizumab) as induction. Demographic- and transplant characteristics were similar between the two groups. At 6 months, patient survival was 88% (15/17) in the induction arm compared to 100% (17/17) in the no-induction arm, P = NS. The 2 causes of death were sepsis and hemolytic uremic syndrome, and both patients died with functioning grafts. Death-censored pancreas and kidney graft survival rates in the induction and the no-induction groups were 88% vs. 100% respectively, in both groups. The incidence of acute rejection (kidney or pancreas) at 6 months did not differ between the two groups (35% in both groups). Biopsy proven pancreas and kidney acute rejections were 35% vs. 24% and 12% vs. 12% in the induction-and no-induction groups, respectively. The incidences of major infection and readmission did not differ between groups. TAC trough levels and mean daily doses of TAC, MMF and steroids did not differ between the two groups at 1, 3, and 6 months. The incidence of event-free survival (no death, rejection, or graft loss) at 6 months was 59% (10/17) in the induction and 65% (11/17) in the no-induction group. Basiliximab and daclizumab appear to be safe in SKPT. However, the preliminary results of this study do not demonstrate a significant benefit in either reducing the incidence of acute rejection or improving outcomes at 6 months. Larger studies with longer follow-up are needed to confirm these findings.