Pediatric Kidney Transplant Outcomes After Kidney Donor Profile Index‐Based Organ Prioritization

ABSTRACT Introduction Following implementation of the U.S. Kidney Allocation System (KAS) in 2014, deceased donor kidneys with a kidney donor profile index (KDPI) < 35% are prioritized for allocation to pediatric candidates. Early post‐KAS data suggested this prioritization may have led to more frequent delayed graft function compared to pre‐KAS, when pediatric allocation priority was based on donor age < 35 years. We sought to understand the impact of this allocation change on longer‐term pediatric kidney transplant outcomes. Methods We used SRTR data to identify all deceased donor kidney transplants with pediatric recipients during two eras: “Pre‐KAS” (12/1/2009–11/30/2014) and “KAS” (12/1/2015–11/30/2020). We used Cox proportional hazards models to calculate the association between study era and all‐cause graft failure (graft failure or death) after adjusting for recipient characteristics. Results Among 4502 included transplants, 2175 (48%) were in the pre‐KAS era and 2327 (52%) in the KAS era. KAS‐era donors were older (median age 23 years, 13% age ≥ 35 years vs. median age 21, 1% age ≥ 35 years), less likely to have diabetes and hypertension, and had lower serum creatinine. Transplantation during the KAS era was associated with a lower hazard of graft failure after adjusting for recipient characteristics (adjusted HR 0.69 0.79 0.91 , p = 0.001). Results were similar in sensitivity analyses limited to recipients < 10 years old and recipients alive with a functioning graft 90 days post‐transplant. Conclusions KDPI‐based prioritization of kidneys for pediatric allocation was associated with a lower risk of graft failure compared to donor age‐based prioritization. Further refining donor risk scores may enable additional improvements in graft survival.