Do six-antigen-matched cadaver donor kidneys provide better graft survival to children compared with one-haploidentical living-related donor transplants? A report of the North American Pediatric Renal Transplant Cooperative Study.

Since 1991, more than 50% of pediatric transplant recipients have received a living donor (LD) kidney, and approximately equals 85% of these allografts were one-haploidentical parental kidneys. Short-term (1 yr) and long-term (5 yr) graft survival of LD kidneys are 10% and 15% better, respectively, than that of cadaver donor (CD) kidneys. Because of these results, children are frequently not placed on a cadaver waiting list until the possibility of a LD is excluded--a process that may take up to 1 yr. The hypothesis for this study was that the graft outcome of a six-antigen-matched CD kidney is superior to that of a one-haploidentical LD kidney, and that children are at a disadvantage by not being placed on a CD list whilst waiting for a LD. The database of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) for 11 yrs (1987-98), was reviewed to identify children who were recipients of a six-antigen-matched CD kidney (primary and repeat transplants), and those who were recipients of a one-haploidentical LD kidney (primary and repeat transplants). Using standard statistical methods, the morbidity, rejection episodes, post-transplant hospitalizations, renal function, long- and short-term graft survival, and half-life of primary recipients were compared in the two groups. Unlike adult patients, only 2.7% (87/3313) of CD recipients in the pediatric age range received a six-antigen-matched kidney, and the annual accrual rate over 11 yrs was never higher than 4%. Comparison of 57 primary six-antigen-CD kidneys (PCD) with 2,472 primary LD (PLD) kidneys revealed that morbidity, rejection rates, and ratios were identical in the two groups. Renal function and subsequent hospitalizations were also identical in the two groups. Five-year graft survival of the PCD group was 90% compared with 80% for the PLD group, and the half-life of the PCD group was 25 +/- 12.9 yrs compared with 19.6 +/- 1.3 yrs. Our data suggest that the six-antigen-matched CD kidney may have less graft loss as a result of chronic rejection and would therefore confer a better long-term outcome. Based on these findings we recommend that all children, whilst waiting for a LD work-up, be listed with the United Network for Organ Sharing (UNOS) registry for a CD kidney.