Background: Waitlisting before 18 years old (yo) confers significant allocation advantages in waiting time and organ priority. This study evaluates the association between race/ethnicity and waitlisting outcomes for young adults (YA) who initiate dialysis as pediatric recipients but were not listed until after 18, thereby missing the “Pediatric Advantage”.
Methods: The OPTN Standard Transplant Analysis and Research file was evaluated for all pediatric (11-17yo) and young adults (YA, 18-25yo) patients waitlisted for KTx alone from 2002-2023. Patients were excluded if they were YA and not yet on dialysis (NYOD) or started dialysis after 18yo. Three cohorts based on age and dialysis status at listing were identified: Peds+NYOD, Peds+OD (on dialysis) at time of listing, and YA+OD<18, indicating those who missed the pediatric listing window. Groups were compared across primary race/ethnicities for patient characteristics, waiting and dialysis time, and transplant characteristics. P-values <0.05 were considered significant.
Results: There were 14,899 patients identified, of which there were 6,087 (40.9%) White, 3,630 (24.4%) Black, 4,260 (28.6%) Hispanic, and 539 (3.6%) Asian patients, with 383 (2.6%) grouped together as Other. There were significant differences in racial make-up of each waitlist/dialysis cohort, with 40.7% of White patients listed as Peds+NYOD and 16.5% listed as YA+OD<18, compared to 21.0% and 26.4% of Black and 28.4% and 19.6% of Hispanic patients, respectively (Fig 1A, p<0.001). Outcomes of listing varied significantly by race, with Black patients most frequently being not transplanted (p<0.001). Black patients spent the longest median time on dialysis prior to waitlisting (301 days in Ped+OD and 1,142d in YA+OD<18) as well as overall (271 days for Peds-NYOD, 672d for Peds+OD, and 2,220d for YA+OD<18, p<0.001, Fig 1C/D). For patients receiving a deceased donor, median kidney donor profile index (KDPI) was highest for Black YA+OD<18 patients (23%) and lowest for Hispanic Peds-NYOD patients (10%). 1-year graft survival was worst for Black patients overall, as well as within each listing cohort (p<0.001).
Conclusions: This study found Black patients were proportionally more likely to be listed as YA+OD<18 while White patients were more likely to be listed as Peds-NYOD. Black and Hispanic patients had longer times on the waitlist and on dialysis prior to transplant and overall Black patients had the worst kidney graft survival. While it is unclear what underlying factors may further exacerbate racial disparities, there are clear differences in waitlisting and outcomes by race in adolescent kidney transplantation.