ENHANCED EXPRESSION OF RESIDENT LEUKOCYTE INTERFERON-GAMMA MESSENGER-RNA IN ENDOMETRIOSIS

PROBLEM: Previous studies have shown that the endometrial epithelial/s tromal cell proliferative activity of endometriosis is significantly l ess than that of normal endometrium and that the concentration of resi dent stromal leukocytes is significantly greater in ectopic than in eu topic endometrium. Other work has shown that interferon gamma (IFN-gam ma), secreted by resident leukocytes, inhibits endometrial cell prolif eration in vitro. Accordingly, we hypothesized that the lower prolifer ative activity of endometriosis may be related to enhanced resident le ukocyte IFN-gamma production. This study was designed to assess whethe r resident leukocytes in endometriosis express IFN-gamma mRNA and to c ompare this expression to that of normal endometrium. METHODS: Biopsie s of ectopic endometrium (N = 16) from women in the follicular phase a nd normal proliferative (N = 9) and secretory (N = 8) endometria were examined for IFN-gamma expression. Using monoclonal antibodies specifi c for CD45 (leukocyte common antigen), CD3 (a T-cell marker) and CD11c (a macrophage marker), leukocyte types were identified immunocytochem ically, followed by in situ hybridization to examine expression of IFN gamma mRNA. RESULTS: Results demonstrated that (1) the overall concent ration of T cells and macrophages expressing IFNgamma mRNA is signific antly greater in endometriosis as compared to eutopic endometrium, and (2) the percent of each leukocyte type expressing IFNgamma mRNA is gr eater in endometriosis than in normal endometrium. CONCLUSIONS: These findings support a possible paracrine role for resident leukocytes in regulating cell proliferation in endometriosis.