Determinants of long-term survival of pediatric kidney grafts reported to the United Network for Organ Sharing kidney transplant registry

Abstract

Pediatric 1-yr kidney graft survival rates have steadily improved in the US so that, by 1998, over 90% of hospital-discharged young recipients had survived the first year post-transplantation (Tx). However, 25% of the early surviving kidney grafts failed at 5 yr, yielding a projected half-life of 10 yr. Given a median age at transplant of 13 yr (range 0-20 yr), 50% of all current pediatric kidney recipients will need a second graft before the age of 25 years. We examined 8,422 pediatric renal transplants reported to the United Network for Organ Sharing (UNOS) Kidney Transplant Registry and, by using a log-linear multifactorial analysis, determined the relative influence of 26 major transplant factors on long-term graft survival. Results are reported as percentages of assignable variation (totaling 100% for all 26 factors combined) in pediatric outcomes beyond 1 yr and as adjusted graft survival rates. Transplant center, recipient race and age, transplant year, and panel-reactive antibody (PRA) had assignable variation percentages of 25, 24, 16, 12, and 4, respectively. When combined, they accounted for 81% of changes in long-term survival. Besides center effects, Blacks, teenagers, and transplants performed before 1994 exhibited significantly (p <0.0001) lower adjusted 5-yr graft survival rates as did the few sensitized (PRA>40%) pediatric patients (p = 0.02). Patients transplanted with a living donor kidney demonstrated a 5% point advantage at 5 yr post-Tx over cadaver donor kidneys (p = 0.001). Although the survival rate of pediatric kidney transplants has improved steadily, the long-term outcomes for teenagers and for Black recipients lag significantly behind those of younger patients and non-Blacks.