Evidence for local production of inhibin A and activin A in patients with ovarian endometriosis

OBJECTIVE: To evaluate the expression of inhibin A and activin A in ovarian endometriosis. DESIGN: Uncontrolled cross-sectional study and controlled prospective in vitro study. SETTING: Academic health centers in Siena, Udine, Sassari, and Milan, Italy. PATIENT(S): A group of women (n = 19) who underwent laparoscopic excision of ovarian endometriotic cysts. INTERVENTION(S): Specimens of serum, peritoneal fluid, and cystic fluid, ovarian tissue for immunohistochemistry, and endometriotic cells for primary culture were collected. Cell cultures were also prepared from proliferative endometrium of women without endometriosis. MAIN OUTCOME MEASURES: Dimeric inhibin A and activin A concentrations in biological fluids; immunostaining of alpha and betaA subunits in ovarian endometrioma; alpha and betaA gene expression in cultured endometriotic cells compared with normal endometrium. RESULT(S): Inhibin A and activin A concentrations in the cystic fluid were slightly higher than in peritoneal fluid and significantly higher than in serum (P<.05). Immunoreactive alpha and betaA subunits were strongly expressed both in the epithelial and stromal components of ovarian endometrioma. The relative abundance of betaA mRNA was significantly decreased in endometriotic cells compared with eutopic stromal cells. CONCLUSION(S): The results of the present study provide evidence for a local production and secretion of inhibin A and activin A in ovarian endometriotic cysts.