Eric Weimer

Introduction In kidney transplant recipients (KTRs), steroid‐free maintenance regimens are used to minimize the negative impact of steroid use. Studies comparing alemtuzumab (ALZ) and anti‐thymocyte globulin (ATG) with rapid steroid withdrawal are limited. The aim of this study was to assess a composite outcome of incidence of de novo donor specific antibodies (dnDSAs), biopsy proven rejection (BPAR), graft failure, or death in KTRs receiving ALZ or ATG with a steroid‐free maintenance regimen. Methods A single‐center, retrospective cohort study was conducted in adult KTRs who underwent rapid steroid withdrawal. There were two cohorts, KTRs who received induction with ALZ compared to ATG. The primary composite outcome was incidence of dnDSAs, BPAR, graft failure, or death. Secondary outcomes included renal function, cytomegalovirus (CMV) and BK viremia, and leukopenia. Results Two hundred twenty‐five KTRs were included where 146 received ALZ and 79 received ATG. The Cox proportional hazard of the primary composite outcome in the ALZ compared to ATG group was not significant (unadjusted model HR 1.37, 95% CI .74–2.55). Individual incidences of composite outcome were similar. There was a difference in estimated glomerular filtration rate at 12 months post‐transplant (55.7 vs. 62.3 mL/min/1.73m 2 , p = .03) and leukopenia at 3 months (3.7 vs. 4.2 × 10 9 /L, p = .03). Other secondary outcomes were similar. Conclusions There was no difference in composite outcome for dnDSAs, BPAR, graft failure, and death.