Increased immunoglobulin response to γ-interferon by lymphocytes from patients with systemic lupus erythematosus

Abstract The factors responsible for abnormal B-cell activation in systemic lupus erythematosus (SLE) are incompletely understood. This study tested the hypothesis that the abnormal B-cell activation observed in human SLE may be due to an augmented response to a helper signal. We demonstrated that non-T cells from 10 of 19 SLE patients increased IgG production in response to interferon-γ (IFN-γ) by a mean factor of 20.9 ± 3.9 over resting levels, while controls stimulated a mean factor of 3.0 ± 0.5 ( P