ADDITIVE EFFECTS OF SUBOPTIMAL DOSES OF ESTROGEN AND CORTISONE ON THESUPPRESSION OF T-LYMPHOCYTE DEPENDENT INFLAMMATORY RESPONSES IN MICE

Many immune-mediated inflammatory diseases are treated with corticoste roids. This type of treatment is, however, often afflicted with side-e ffects such as osteoporosis and atherosclerosis. During the last decad es also sex steroids, such as estrogens, have been shown to have immun oregulatory properties. In this report we studied the effect of combin ed 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 ho rmones display additive effects on suppression of DTH. In contrast, su ch additive effects were not observed in granulocyte-mediated inflamma tion. 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 res ults could indicate the potential to use combinations of corticosteroi ds and estrogen in the treatment of T lymphocyte dependent rheumatic d iseases such as rheumatoid arthritis (RA). In addition, the B lymphocy te stimulation by estrogen in cortisone exposed mice stimulate to futu re studies in humans if estrogen containing contraceptives or post men opausal hormone treatment could have triggering effects in patients wi th immune complex mediated diseases also when they are on corticostero id treatment.