A randomized, double-blinded comparison of thymoglobulin versus atgam for induction immunosuppressive therapy in adult renal transplant recipients

TLDR: Brief (7-day) induction with Thymoglobulin resulted in less frequent and less severe rejection, a better event-free survival, less cytomegalovirus disease, fewer serious adverse events, but more frequent early leukopenia than induction with Atgam.

Abstract: Background The aim of this study was to compare the efficacy and safety of Thymoglobulin (a rabbit-derived polyclonal antibody) to Atgam (a horse-derived polyclonal antibody) for induction in adult renal transplant recipients Methods Transplant recipients (n=72) were ran domized 2:1 in a double-blinded fashion to receive Thymoglobulin (n=48) at 15 mg/kg intravenously or Atgam (n=24) at 15 mg/kg intravenously, intraopera tively, then daily for at least 6 days Recipients were observed for at least 1 year of follow-up Results By 1 year after transplantation, 4% of Thymoglobulin-treated patients experienced acute rejection compared with 25% of Atgam-treated patients (P=0014) The rate of acute rejection was lower with Thymoglobulin than Atgam (relative risk=009; P=0009) Rejection was less severe with Thymoglobulin than Atgam (P=002) No recurrent rejection occurred with Thymoglobulin compared with 33% with Atgam (P=NS) Patient survival was not different, but the composite end point of freedom from death, graft loss, or rejection, the event-free survival, was superior with Thymoglobulin (94%) compared with Atgam (63%; P=00005) Fewer adverse events occurred with Thymoglobulin (P=0013) Leukopenia was more common with Thymoglobulin than Atgam (56% vs 4%; P<00001) during induction The mean absolute lymphocyte count remained below baseline with Thymoglobulin throughout the study (P<0007), but with Atgam, significant lymphocyte reductions occurred only at day 7 The incidence of cytomegalovirus disease was less with Thymoglobulin than Atgam at 6 months (10% vs 33%; P=0025) Conclusions Brief (7-day) induction with Thymoglobulin resulted in less frequent and less severe rejection, a better event-free survival, less cytomegalovirus disease, fewer serious adverse events, but more frequent early leukopenia than induction with Atgam These results may in fact be explained by a more profound and durable beneficial lymphopenia