Increased spontaneous activity of antibody‐forming cells in the peripheral blood of patients with active sle

Abstract
Thirty‐seven patients with criteria for systemic lupus erythematosus (SLE) and 18 normal controls were studied for their spontaneous background IgM antibody plaque‐forming cell number to specific chemical haptens. Active SLE patients had significantly more plaque‐forming cells in their peripheral blood to a total of five chemical determinants than did patients with inactive disease or controls. This increased number of plaque forming‐cells correlated with depressed serum C3 levels by Spearman rank‐order analysis. The finding of elevated numbers of spontaneous IgM plaque‐forming cells to defined chemical haptens supports the concept that active SLE demonstrates a generalized increase in B‐cell activity toward a variety of antigens.