The impact of nonidentical ABO deceased donor kidney transplant on kidney utilization

Blood type AB kidney transplant candidates have the shortest waiting times, yet the current allocation system allows allocation of type A donor kidneys to type AB recipients.

United Network for Organ Sharing/Organ Procurement and Transplantation Network data between 1995 and 2004, retrospective observational study.

189,773 candidates listed for kidney-only transplant; 93,604 kidneys transplanted, 15,580 kidneys discarded.

Blood type and demographic/clinical variables.

The extent of disparities in waiting times and concurrent differences in recovery, discard, live donor, and deceased donor transplant rates.

Blood type O, A, B, and AB candidates constituted 48%, 34%, 14%, and 4% of the list, respectively. Live donor transplant rates were lowest for type AB candidates (13.4% vs 15.5%, 16.8%, and 15.2%; P < 0.001). On multivariate analysis, type AB candidates had a 1.5-fold greater chance of receiving deceased donor kidney transplants than blood group A candidates (95% CI, 1.45-1.55). Recovery rates of type AB kidneys were similar to those for other blood types, whereas discard rates of type AB kidneys were significantly higher (adjusted OR [aOR], 1.71; 95% CI, 1.56-1.89) for both expanded criteria (aOR, 1.78; 95% CI, 1.52-2.09) and standard criteria donors (aOR, 1.67; 95% CI, 1.48-1.89).

Observational data. Potential confounding from unmeasured covariates.

Allocation of type A kidneys to type AB recipients not only increases disparities in waiting times between these 2 groups; but concurrent with the shorter waiting times for type AB candidates, there is suboptimal use of type AB deceased donor and living donor kidneys.