Kidney Transplantation in ≤15 kg Children: Outcomes and Prognostic Indicators-A Review of the Organ Procurement and Transplantation Database

Background: Approximately 2500 pediatric patients are awaiting kidney transplantation in the United States, with <5% comprising those <= 15 kg. Transplant in this cohort is often delayed by center-based growth parameters, often necessitating transplantation after the initiation of dialysis. Furthermore, prognostication remains somewhat ambiguous. In this report, we scrutinize the Organ Procurement and Transplantation Network (OPTN) data from 2001 to 2021 to help better understand specific variables impacting graft and patient outcomes in these children. Methods: The OPTN kidney transplant dataset from 2001 to 2021 was analyzed. Inclusion criteria included age <18 years, weight <= 15 kg, and recipient of primary living donor kidney transplantation (LDKT) or deceased donor kidney transplantation (DDKT). Patient and graft survival probabilities were calculated using the Kaplan-Meier method. The Cox proportional hazards model was used to calculate hazard ratio (HR) and identify variables significantly associated with patient and graft survival. Results: Two thousand one hundred sixty-eight pediatric transplant recipients met inclusion criteria. Patient survival at 1 and 3 years was 98% and 97%, respectively. Graft survival at 1 and 3 years was 95% and 92%, respectively. Dialysis was the sole significant variable impacting both patient and graft survival. Graft survival was further impacted by transplant era, recipient gender and ethnicity, and donor type. Infants transplanted at Age 1 had better graft survival compared with older children, and nephrotic syndrome was likewise associated with a better prognosis. Conclusion: Pediatric kidney transplantation is highly successful. The balance between preemptive transplantation, medical optimization, and satisfactory technical parameters seems to suggest a "Goldilocks zone" for many children, favoring transplantation between 1 and 2 years of age.