Influence of steroid hormones on proliferation of peripheral blood mononuclear cells in patients with rheumatoid arthritis.

Sex steroids are believed to modulate the immune system in rheumatoid arthritis (RA). Since receptors for sex steroids are present on T-lymphocytes, which are thought to play a major role in the pathogenesis of RA, it is suggested that gonadal steroids can mediate their immunomodulating effect directly on T-lymphocytes. Recently a specific method for activating T-lymphocytes with immobilized anti-CD3 monoclonal antibodies was described. We investigated the influence of oestradiol, progesterone, testosterone and cortisol on lymphocytes stimulated by anti-CD3 mAb and PHA of postmenopausal women, comparing female patients with rheumatoid arthritis and age-matched control patients. The results show that oestradiol, progesterone and testosterone do not influence lymphocyte proliferation when stimulated with anti-CD3 mAb or phytohaemagglutinin (PHA). Cortisol, however, can suppress lymphocyte proliferation even at physiological concentrations in both patients with RA and controls. Inhibition of proliferation by cortisol is dose-related and has no significant correlation with RA disease activity. This inhibition differs individually and might explain the often variable response to corticosteroids in vivo.