The significance of mixed lymphocyte culture in related renal transplantation.

Eighty-one donor-recipient pairs were evaluated prior to renal transplantation to obtain histocompatibility profiles. Standard tissue typing was used to detect serologically defined A and B locus antigens, and mixed lymphocyte cultures were employed to detect lymphocyte defined antigens. Results of both tests were correlated with each other and with allograft rejection. It was shown that as serologically defined histocompatibility at the A and B loci decreases, both the rate of graft rejection and the percentage of high mixed lymphocyte culture stimulation increase. Within each serologically defined category were found patients with a high and a low stimulation index in mixed lymphocyte culture. Regardless of the degree of serologically defined histocompatibility, patients with a high stimulation index had a statistically significant higher graft rejection rate than did patients with a low stimulation index. It appears that the mixed lymphocyte culture assay is a method superior to standard tissue typing in predicting renal allograft rejection with related donors, and therefore all potential donors for renal transplantation should be screened, utilizing the mixed lymphocyte culture technique.