Additive effects of suboptimal doses of estrogen and cortisone on the suppression of T lymphocyte dependent inflammatory responses in mice.

Many immune-mediated inflammatory diseases are treated with corticosteroids. This type of treatment is, however, often afflicted with side-effects such as osteoporosis and atherosclerosis. During the last decades also sex steroids, such as estrogens, have been shown to have immunoregulatory properties. In this report we studied the effect of combined treatment with suboptimal doses of dexamethasone and estradiol on T lymphocyte mediated delayed type hypersensitivity (DTH), granulocyte-mediated inflammatory responses, immunoglobulin production and antigen specific antibody responses in mice. The results show that the two hormones display additive effects on suppression of DTH. In contrast, such additive effects were not observed in granulocyte-mediated inflammation. B lymphocyte activity, measured by immunoglobulin production and antigen-specific antibody responses, were increased after exposure to estradiol and suppressed by dexamethasone. In mice treated with both hormones the up regulation of B lymphocytes was still evident. The results could indicate the potential to use combinations of corticosteroids and estrogen in the treatment of T lymphocyte dependent rheumatic diseases such as rheumatoid arthritis (RA). In addition, the B lymphocyte stimulation by estrogen in cortisone exposed mice stimulate to future studies in humans if estrogen containing contraceptives or post menopausal hormone treatment could have triggering effects in patients with immune complex mediated diseases also when they are on corticosteroid treatment.