Low Dose Anti-Thymocyte Globulin Has no Disadvantages to Standard Higher Dose in Pediatric Kidney Transplant Recipients

Abstract Introduction Rabbit anti-thymocyte globulin (rATG) dosing strategies for induction in pediatric kidney transplantation vary between centers. It is not known whether a lower rATG induction dose provides safe and effective immunosuppression compared to a “standard” higher dose. Methods Retrospective multi-center study of all isolated first-time kidney transplant recipients 4.5 mg/kg) exposure groups. Outcomes examined included 12 months post-transplant graft function (eGFR), and the occurrence of acute rejection, donor specific antibody (DSA), neutropenia, and viral infection (CMV, EBV, BKV), and 24-month outcomes of PTLD occurrence, patient and graft survival. Results 235 patients were included. Baseline features of the low and standard rATG dose groups were similar. By 12 months, rATG dose group had no significant impact on the occurrence of neutropenia, positive DSA or viral PCR. Graft function was similar. Acute rejection rates were similar at 17% (low dose) vs. 19% (standard dose), p-value 0.13. By 24 months, graft survival (96.4% vs. 94.6%), and patient survival (100% vs. 99.3%) were similar between the low and standard dose groups (p-values 0.54, and 0.46), while occurrence of PTLD trended higher in standard dose group (0% vs. 2.6%, p-value 0.07). Conclusions Low rATG induction dose ≤4.5 mg/kg provided safe and effective outcomes in this multi-center low immunologic risk pediatric cohort. Prospective studies are warranted to define the optimal rATG induction dose in pediatric kidney transplantation.