Suppressor cells assayed by numerical and functional tests in chronic renal failure.

Suppressor cells were assayed by numerical and functional tests in adults on chronic hemodialysis. Peripheral blood mononuclears (PBM) were classified as total T-cells by E-rosettes and by the monoclonal antibody OKT3, as T-cell subsets by OKT4 (inducer/helper T-cells) and OKT8 (cytotoxic/suppressor T-cells) and as B-cells by the presence of surface immunoglobulin. The suppressive effect of PBM pretreated with either Concanavalin A (Con A), sodium periodate, or serum rich in immune complexes, on normal homologous phytohemagglutinin (PHA) lymphocyte transformation, was determined. Usual tests of T-cell function were not done. T lymphopenia was due to significant diminution (P less than 0.002) in numbers of OKT4+ cells in patients (516 +/- 44 cells/mm3, mean +/- sem) as compared to controls (906 +/- 96 cells/mm3). The number of OKT8+ cells in patients was not different from normal although their percentage (45 +/- 4%) was slightly higher than controls (36 +/- 5%) (P less than 0.10). Suppressor activity using only a suboptimal dose of Con A (5 micrograms/ml), was significantly lower (P less than 0.002) in uremic patients (36 +/- 12%) than in controls (67 +/- 7%). An important finding was that no significant correlations were detected between the numerical and functional assays of suppression used or between any of these immunological tests and biochemical parameters studied. The implications of these results for immunoparesis in uremia are discussed with particular reference to the discordance between marker and functional assays of suppressor cells.