David M Vock

Background The optimal age of kidney transplantation for infants and toddlers with kidney failure is unclear. We aimed to evaluate the patient survival associated with kidney transplantation before 2 years of age versus remaining on the waitlist until ≥2 years. Method We used the Scientific Registry of Transplant Recipients to identify all children added to the deceased‐donor waitlist before 2 years of age between 1/1/2000 and 4/30/2020. For each case aged <2 years at transplant, we created a control group comprising all candidates on the waitlist on the case's transplant date. Patient survival was evaluated using sequential Cox regression. Dialysis‐free time was defined as graft survival time for cases and the sum of dialysis‐free time on the waitlist and graft survival time for controls. Results We observed similar patient survival for posttransplant periods 0–3 and 4–12 months but higher survival for period >12 months for <2‐year decreased‐donor recipients (aHR: 0.32; 95% CI: 0.13–0.78; p = .01) compared with controls. Similarly, patient survival was higher for <2‐year living‐donor recipients for posttransplant period >12 months (aHR: 0.21; 95% CI: 0.06–0.73; p = .01). The 5‐year dialysis‐free survival was higher for <2‐year deceased‐ (difference: 0.59 years; 95% CI: 0.23–0.93) and living‐donor (difference: 1.84 years; 95% CI: 1.31–2.25) recipients. Conclusion Kidney transplantation in children <2 years of age is associated with improved patient survival and reduced dialysis exposure compared with remaining on the waitlist until ≥2 years.