The effect of HLA–A, –B matching on cadaver renal allograft rejection comparing public and private specificities

Data collected prospectively on 3811 cadaver renal transplants performed between June 1977 and July 1982 by the 42 member institutions of the South-Eastern Organ Procurement Foundation (SEOPF) were analyzed to determine whether donor-recipient compatibility based on public rather than private HLA-A,-B specificities influenced the beneficial effect of HLA matching on outcome. HLA compatibility was calculated considering match and mismatch based on common private or various public (crossreactive group, [CREG]) specificities. Donor-recipient compatibility using certain CREG assignments provided an equivalent means of stratifying graft outcome by the degree of HLA-A,-B match or mismatch, and other CREGs assignments did not. Multivariate Cox regression analysis of donor-recipient compatibility based on certain public antigens showed as high an association (P <10^-5) between good matching and decreased graft rejection as did matching for private antigens alone. Patient stratification by HLA match provided a stronger association with graft outcome than by HLA mismatch, irrespective of whether private or public antigens were considered. The likelihood of finding a better match was significantly increased using CREG assignments, and patients with at least one matched private antigen had equivalent or better graft survival when additional public antigens were matched.These findings indicate that with conventional immunosuppressive therapy: (1) matching of private or public HLA-A,-B antigens plays a highly significant role in decreasing renal allograft rejection; (2) matching based on certain public antigens can provide the same or a better association with outcome as private antigens; and (3) the association (crossreactivity) of various HLA specificities can be defined on a functional basis in terms of graft survival.