T-lymphocyte subsets when measured in steroid responsive nephrotic syndrome (SRNS) have demonstrated significant variance from normal values. T-cell subsets were studied by using two-color flow cytometric analysis in 32 children (9.2 +/- 5 years of age) with SRNS. The children were divided into four groups: a) SRNS in acute relapse, on prednisone; b) SRNS in acute relapse, off prednisone; c) SRNS in long-term remission, off prednisone (nephrotic controls); d) patients in remission on long-term prednisone therapy; and e) 15 age-matched normal controls. Children suffering an acute relapse of SRNS showed an increase in Leu2a+/DR+ (CD8) activated lymphocytes (P less than 0.05), a decrease in Leu4a+ total T-lymphocytes (P = 0.01) and a decrease in Leu3a+ (CD4) helper T-cells (P less than 0.05) when compared to normal controls and nephrotic controls. Though some subset changes may represent a prednisone effect and the functional role of these lymphocytes in the disease process is unknown, this study provides additional evidence to support a role for abnormal T-cell subsets in the etiology of SRNS.