Abstract
The major histocompatibility complex (MHC) was discovered and so named because of its association with allograft rejection in animals. Thus, when kidney transplantation in humans became a reality it was not surprising that the degree of matching of organ donors and recipients for the antigens of the human MHC (HLA antigens) strongly predicted the probability of graft acceptance. The initial experience with kidney transplantation, which involved living related donors, demonstrated that the number of shared HLA chromosomal segments (haplotypes) predicted the outcome and the degree of immunosuppressive therapy required. Likewise, in 1966 Terasaki and coworkers reported an association between HLA . . .