Defective cell-mediated immunity in lipoid nephrosis.

Cell-mediated immunity (CMI) was studied in 28 patients with biopsy-proven lipoid nephrosis (LN). The LN patients with nephrotic syndrome (NS) had a significant depression in CMI, characterized by impaired delayed hypersensitivity skin reactivity to purified protein derivative (PPD), depressed local graft-versus-host reaction (GVHR), decreased proportion of T lymphocytes and diminished lymphocyte transformation to phytohemagglutinin (PHA). Concanavalin A (Con A)-induced suppressor cell activity (SCA) was found to be significantly increased in LN patients with NS compared to that in normal individuals. In contrast, the mean levels of CMI and SCA studied in LN patients in remission and in patients with chronic mesangial proliferative glomerulonephritis (CGN) did not differ from normal subjects. Our findings support the notion that at least in some LN patients with the NS, activated suppressor cells are present and possibly account for their decreased CMI.