Rejection profile of recent pediatric renal transplant recipients compared with historical controls: a report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS).

Historically, higher acute rejection rates, earlier first rejection, and an inability to reverse the rejection characterize pediatric renal transplantation. In recent years, short-term (1-year) graft survival of pediatric renal transplants has steadily improved. To test the hypothesis that these improvements were mediated by changes in acute rejection, we considered the rejection profile of patients who received a renal allograft between 1987 and 1989 (cohort A) and compared it with recipients transplanted between 1997 and 1999 (Cohort B). Cohort A comprised 1469 transplants and cohort B comprised 1189 transplants. Restricting the data to the first year of follow-up, rejection ratios were 1.6 and 0.7, respectively (p < 0.001). Sixty per cent of the later cohort (B) were rejection free at 1 year, compared with 29% for the earlier cohort (A) (p < 0.001). Controlling for donor source, the rejection reversal rate for the later cohort was significantly better than that of the early cohort (p < 0.001). Cumulative distribution of times to first rejection was significantly better for cohort B (p < 0.001). One-year graft survival for cohort B at 94% was significantly better than 80% for cohort A (p < 0.001). We conclude that the improved short-term graft survival is mediated by improvements in the rejection profile in more recently transplanted patients and that this may translate into a better half-life for pediatric renal transplant recipients who received an allograft in the years 1997-99.