Transplantation of A2 kidneys into B and O recipients leads to reduction in waiting time: USRDS experience.

Introduction. Strategy of transplanting kidneys from A2 donors into patients with blood group B and O recipients has been used to alleviate the long waiting times. Materials and Methods. We used an inception cohort of US Renal Data System data base with patients older than 18 years who underwent renal transplantation between January 1995 and July 2006. The primary outcome variable was allograft loss (including death). Bivariate analysis of factors associated with receiving A2 or A2B kidneys was performed with chi-square testing for categorical variables (Fisher's exact test used for violations of Cochran's assumptions) and Student's t test for continuous variables (Mann-Whitney U test used for nonnormally distributed variables). Results. There were 150,118 first kidney transplants of whom 113 received kidney transplant from A2 to O, and 125 patients received A2 to B kidney transplant. Compared with other recipients from the same blood group, recipients of A2 kidneys had significantly shorter wait times. O recipients had a median wait time of 1.63 years (range 0.00-17.21 years), whereas O recipients who received A2 kidneys had a median wait time of 0.70 years (range 0.02-1.47 years; P < 0.001). B recipients had a median wait time of 1.90 years (range 0.00-17.52 years), whereas B recipients who received A2 kidneys had a median wait time of 0.74 years (range 0.10-5.21 years; P < 0.001). There was no significant difference in graft loss or death between A2 to O and B versus all other recipients. Conclusions. The results showed that comparatively few patients received A2 to B or O kidney transplant.