Defective B cell function in systemic lupus erythematosus.

The in vitro synthesis of specific anti-influenza virus antibody was measured in cultures of peripheral blood lymphocytes from 25 patients with systemic lupus erythematosus (SLE) and 23 control subjects. Whilst all cultures derived from normal individuals synthesized specific antibody, cultures from patients with SLE were consistently unable to produce anti-influenza antibody. This defect could not be corrected by manipulating the culture conditions or by in vivo immunization. Co-cultivation of separated SLE-B or control B cells, with SLE-T or control T cells showed that the immunodeficiency exhibited by the SLE peripheral blood lymphocytes resides in the B cells.