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

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.

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.

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 _0.690.79_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.

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.