Human renal allograft and peripheral blood T lymphocyte subpopulations during the onset and treatment of rejection.

In order to study the changes in T lymphocyte subpopulations in both allografts and peripheral blood of patients following renal transplantation, we have examined 72 fine needle allograft aspirates and 56 peripheral blood samples from 24 patients during the first month following transplantation. The patients were studied before, during and after rejection episodes. Monoclonal antibodies directed against T helper (TH) and T cytotoxic/suppressor (TCS) cells were used to identify lymphocyte subpopulations in the allograft aspirates and peripheral blood. The ratio of TH:TCS cells in both the allograft aspirates and peripheral blood decreased significantly (p less than 0.01) during the three days before rejection became clinically manifest. During rejection, the aspirate TH:TCS ratios, but not the peripheral blood TH:TCS ratios, remained depressed. Following successful treatment for rejection, the aspirate TH:TCS ratios returned to levels found in non-rejecting allografts. However, in the allografts which were lost as a result of rejection or had persistent rejection despite treatment, the aspirate TH:TCS ratios, but not peripheral blood TH:TCS ratios, remained significantly low (p less than 0.01) when compared with the successfully treated allografts. Our study indicates that TH:TCS ratios, particularly in allograft aspirates, may be of value in predicting the onset and outcome of renal allograft rejection.