Analysis of HL-A incompatibility in human renal transplants.

The matching criteria of counting the number of HL-A incompatibilities, the number of compatible antigens, and of ratios (net histocompatibility ratio) were evaluated. In order to avoid bias, the data were analyzed with the aid of computers, taking many different cutoff points. The probability value of statistical significance can be shown to vary considerably depending on the time selected for evaluating the clinical ranks and the clinical ranks which are considered to be “successful” or “failure.” Overall, the data indicate that because of the large number of patients who do well in spite of incompatibility, a more suitable means by which successful transplants can be predicted will be required. Since HL-A antigens are still the primary transplantation antigens (as shown by the successful HL-A-identical sibling transplants), empiric knowledge on the types of incompatibilities which can result in good graft survival must be developed.