Human leukocyte antigen in the allocation of kidneys from cadaveric donors in the United States

Minorities wait longer for a cadaveric donor kidney transplant than whites. For example, the median waiting time to transplant for candidates listed from 1997 to 1998 was 874 days for whites, 1,493 days for blacks, 1,281 days for Hispanics, 1,491 days for Asians, and 1,466 days for others. The current allocation algorithm has been criticized as contributing to decreased access to transplants for racial minorities. There are two levels in the current algorithm: The first is mandatory national sharing between donors and patients with zero human leukocyte antigen (HLA)-A, B, and DR mismatches. The second occurs if there are no candidates and local placement is accomplished based on an algorithm with an HLA component that assigns seven, five, and two points to zero, one, and two HLA-B and DR mismatches, respectively. An analysis of the data shows that a higher percentage of white recipients (21%) received zero antigen mismatched kidneys compared with other races: blacks (7%), Hispanics (14%), and Asians (7%). Whites also received the highest percentage of kidneys with zero B and DR mismatches and one B and DR mismatch compared with the other races. These data indicate that the current algorithm favors whites over minorities, and it is most likely that giving points for HLA-B matching is a strong contributory factor. To address this inequity, the Organ Procurement and Transplantation Network and United Network for Organ Sharing Board of Directors approved a recommendation in November 2002 to change the HLA points to award two points for zero DR mismatches and one point for one DR mismatch. Obviously it will take some time to gather sufficient data to allow meaningful analysis of the effect of the policy change.