Human T‐Lymphocyte Subpopulations: Alterations in Systemic Lupus Erythematosus

Abstract

Sharply reduced proportions of T cells with Fc receptors for IgG (T_G cells) were observed in blood samples from patients with systemic lupus erythematosus (SLE), mainly with active disease. This T-cell subset has previously heen shown to be a suppressor in the pokeweed mitogen (PWM)-dependent B-cell differentiation. In contrast, the percentages of T cells with Fc receptors for IgM (T_M cells), which have been shown to help inimunoglobulin production, were not different from those of normals. T_G cells present in the circulation of SLE patients were analysed for their functional capacities in antibody-dependent cell-mediated cytotoxicity and in the suppression of a PWM-induced B-cell differentiation. In both these assays T_G cells from SLE patients had normal effector cell activity. This suggests that the T-cell defects present in SLE patients are mainly of a quantitative rather than a qualitative type.