THE NATIONAL MARROW DONOR PROGRAM

As the number of successful marrow transplants has increased, the lack of HLA-identical sibling donors for 60 to 70 percent of transplant ca ndidates has become a serious problem. Pilot studies established that marrow transplantation between phenotypically HLA-identical, unrelated individuals can be accomplished successfully. Therefore, the National Marrow Donor Program was established to develop a large file of volun teer marrow donors and to serve as a center for the coordination of th e donor search and donor-recipient matching processes. By November 199 1, 63 months after the program was established, 457,205 potential marr ow donors typed for HLA-A and -B antigens had agreed to be listed in t he marrow donor registry. A donor search had been initiated for 8481 p atients. At least one potential donor matched for at least three of th e four HLA-A and -B antigens was located for 99.8 percent of patients. Among the 3156 searches that were completed, 940 (29.8%) resulted in a transplant. The median time in which to locate a matched donor, comp lete all predonation evaluations, and obtain donor consent was 208 day s. The most common diagnosis in patients who underwent transplantation was chronic myelogenous leukemia (42.0%). When this analysis was comp leted in November 1991, the National Marrow Donor Program was operatin g a national network of 99 donor centers and 53 transplant centers. Th e donor file was increasing rapidly, and a follow-up system was in pla ce to determine the effects of donation on the donors and the outcome in the patients who underwent transplantation. This national network o f donor and transplant centers exists and is now facilitating unrelate d-donor marrow transplants. The National Marrow Donor Program made it possible to locate donors for many patients in need of a transplant an d helped to determine the role of unrelated-donor marrow transplants i n the treatment of many diseases.