HLA matching

INTRODUCTION — The evidence that antigens of the HLA system provide the major barrier to acceptance of renal transplants was first obtained with living-related donor transplants. Graft survival was superior in sibling pairs having both the same serologically defined HLA antigens and a nonreactive in vitro mixed lymphocyte proliferative response when compared to randomly matched cadaveric donors treated with the same immunosuppressive drugs, principally azathioprine and prednisone. (The mixed lymphocyte response [MLR] is an in vitro estimate of incompatibility in which the degree of proliferation of the recipient lymphocytes to donor lymphocytes is measured.) There was an intermediate level of graft survival in haploidentical parent to child or sibling to sibling transplants, in which one but not both of the haplotypes matched.