Mononuclear cells in renal allografts. Correlation with peripheral blood T lymphocyte subpopulations and graft prognosis.

Cellular infiltrates in 20 renal allograft biopsies taken at the time of acute rejection episodes were analyzed with antibodies reactive with monocytes (BRL antihuman monocyte monoclonal antibody), T lymphocyte subpopulations (OKT- and Leu-series of monoclonal antibodies), and B lymphocytes (heterologous antihuman IgM antibodies). For demonstration of the various mononuclear cells, an indirect immunoperoxidase technique was used. The number of monocytes in the infiltrates varied from 10-20%; the number of B lymphocytes was always below 10%. The T lymphocytes accounted for 50-90% of the total number of mononuclear cells. The OKT4/OKT8 ratios for the T lymphocytes in the graft infiltrates were correlated with the peripheral blood OKT4/OKT8 ratios measured by indirect fluorescence and flow cytometry. The OKT4/OKT8 ratios for perivascular infiltrates correlated far better with peripheral blood OKT4/OKT8 ratios (r = 0.72) than did the OKT4/OKT8 ratios for interstitial infiltrates (r = 0.58). Low or inverted OKT4/OKT8 ratios and low or inverted Leu 3a/Leu 2a ratios were associated with a high risk of irreversible graft rejection (P less than 0.001 for perivascular infiltrates).