Indomethacin inhibits in vitro immunoglobulin production by human B-lymphocytes.

Immunoglobulin production from human B-lymphocytes stimulated in vitro with pokeweed mitogen (PWM) was measured after 11 days of cell culture. IgM and IgG levels in culture supernatants were quantified using ELISA techniques. Addition of the prostaglandin cyclooxygenase inhibitor indomethacin (10(-7) M) to cell cultures concurrently with PWM, inhibited both IgM and IgG synthesis by 80-90% in the four individuals studied. Reduction of immunoglobulin production was apparently concentration-related over the range studied (10(-6)-10(-8) M) and was not associated with cytotoxicity. If this action of indomethacin results from inhibition of cyclooxygenase, then prostaglandins or other arachidonic acid products could be involved in the regulation of human B-lymphocyte immunoglobulin production.