Increased access to transplantation for blood group B cadaveric waiting list candidates by using A2 kidneys: time for a new national system?

Since blood group B end-stage renal disease (ESRD) patients have less access to donor kidneys and a higher minority composition than any other blood group, the United Network for Organ Sharing (UNOS) approved a voluntary national kidney allocation variance to allow organ procurement organizations (OPOs) to preferentially allocate A2 and A2B kidneys to B candidates. The Midwest Transplant Network OPO has preferentially allocated and transplanted kidneys from blood group A2 and A2B donors to our blood group B waiting list candidates for more than 7 years to increase access to kidneys for the B candidates on our OPO-wide waiting list. Between 1994 and 2000, a total of 121 blood group B ESRD patients from our OPO-wide cadaveric kidney waiting list were transplanted. Thirty-four per cent (41/121) of those B candidates received either an A2 or an A2B kidney. One- and 5-year graft survival rates for the group of B recipients of A2 or A2B kidneys were 91 and 85% (died with functioning graft [DWFG] censored), respectively, which were not significantly different from those of 91 and 80% for the 80 B recipients of B or O kidneys (Wilcoxon = 0.48; log-rank = 0.55). These data support the national trial for additional OPOs to voluntarily allocate A2 and A2B kidneys preferentially to B waiting list candidates, thus increasing access of blood group B patients to renal transplantation.