Clinical Correlates and Outcomes of Dual Basiliximab and Antithymocyte Globulin Induction in Kidney Transplant Recipients: A National Study

Background. The unplanned use of dual induction therapy with interleukin-2 receptor-blocking antibodies (IL2rAb) and antithymocyte globulin (ATG) may portend adverse outcomes. Methods. We used national transplant registry data to study clinical correlates and outcomes of single versus dual induction therapy in adult kidney-only transplant recipients in the United States (2005-2018). The risk of death and graft loss at 1 and 5 y, according to induction therapy type, was assessed using multivariate Cox regression analysis (adjusted hazard ratio with 95% upper and lower confidence limits [LCLaHRUCL]). Results. Of the 157 351 recipients included in the study, 67% were treated with ATG alone, 29% were treated with IL2rAb alone, and 5% were treated with both. Compared with IL2rAb alone, the strongest correlates of dual induction included Black race, calculated panel reactive antibody ≥80%, prednisone-sparing maintenance immunosuppression, more recent transplant eras, longer cold ischemia time, and delayed graft function. Compared with ATG alone, dual induction was associated with an increased 5-y risk of death (aHR1.071.151.23; P < 0.0001), death-censored graft failure (aHR1.051.131.22; P < 0.05), and all-cause graft failure (aHR1.061.121.18; P < 0.0001). Conclusions. Further research is needed to develop risk-prediction tools to further inform optimal, individualized induction protocols for kidney transplant recipients.