Steroid maintenance in repeat kidney transplantation: Influence of induction agents on outcomes

Abstract

The influence of steroid maintenance on the outcomes of repeat kidney transplant (RKT) recipients with respect to induction type is unclear. Using the Organ Procurement and Transplant Network/United Network of Organ Sharing (OPTN/UNOS) database, we identified patients (≥18 years) who underwent deceased donor RKT from January 2000 to December 2008 after receiving induction with rabbit-antithymocyte globulin (r-ATG), alemtuzumab or an IL-2 receptor blocker (IL-2B) and were discharged on a calcineurin inhibitor/mycophenolate mofetil regimen with or without steroids. Of 5634 patients, 3643 received r-ATG (steroid = 3157, no-steroid = 486), 448 alemtuzumab (steroid = 196, no-steroid = 252) and 1543 an IL-2B (steroid = 1465, no-steroid = 78). Unadjusted graft survivals were similar for the no-steroid versus steroid groups for induction with r-ATG [hazard ratio (HR) 0.85 and 95% confidence interval (95% CI) 0.70-1.03, P = 0.10], alemtuzumab (HR 0.76, 95% CI 0.51-1.14, P = 0.18) and IL-2B (HR 0.77, 95% CI 0.56-1.70, P = 0.23). In the adjusted model, steroid use improved graft survival in alem-tuzumab (HR 0.44, 95% CI 0.25-0.76, P = 0.003) but not in the r-ATG (HR 0.86, 95% CI 0.68-1.09, P = 0.21) or IL-2B (HR 0.98, 95% CI 0.56-1.70, P = 0.94) groups. Steroid use was asso-ciated with inferior patient survival in unadjusted (HR 1.30, 95% CI 1.17-1.44, P <0.001) and adjusted (HR 1.29, 95% CI 1.14-1.45, P <0.001) models for r-ATG induction, whereas this was not observed with alemtuzumab (unadjusted HR 1.11, 95% CI 0.89-1.37, P = 0.36; adjusted HR 0.90, 95% CI 0.68-1.20, P = 0.49) or IL-2B (unadjusted HR 1.01, 95% CI 0.87-1.18, P = 0.87; adjusted HR 1.15, 95% CI 0.97-1.38, P = 0.12) inductions. Our study showed a graft survival benefit in the alemtuzumab- and patient death risk in the r-ATG-induced RKT recipients discharged on steroids.