Inflammatory pathway in eutopic endometrium of women with endometriosis

Endometriosis is a complex disorder among women of reproductive age associated with chronic pelvic pain, debilitating dysmenorrhoea and infertility . These symptoms are thought to be the consequence of an inflammatory environment within the pelvis. Recently, a growing body of evidence indicates that abnormal inflammation is not only present in the pelvic endometriotic lesions but also in the eutopic endometrium of these patients leading to a proinflammatory environment unsuitable for implantation. Hence the aim of this study was to analyze by immunoblotting and by polymerase chain reaction the expression of inflammatory cytokines known to be involved in chronic endometritis (CE), in the eutopic endometrium of women affected by endometriosis. MATERIALS AND METHODS Endometrial samples were obtained from 12 patients 6 women affected by endometriosis and 6 controls. Histological and immunoistochemical study: An immunohistochemical investigation of tissue samples was performed utilizing antibodies anti-TNF, anti-IL-1, anti-IL-6, anti-IL-8, anti-IL-10, anti-MCP-1, and CD 138. Western blot (WB): Approximately 50 mg of endometrium tissue collected were prepared for Western blot. The image was analysed by Uvitec, which detects the chemiluminescent blots of proteins staining (TNF, IL-1, IL-6, IL-8, IL-10, MCP-1). PCR analysis: In 6 out of 12 patients PCR analysis was also performed in order to confirm immunoistochemical and WB analysis RESULTS Histological and immunohistochemical study and Western blotting The examination of endometrium specimens revealed the negative reaction for the antibodies anti-IL-6 and IL-10 in patients and controls; a strong positive reaction for the antibodies anti-IL-1β, IL-8, MCP1, an intermediate positive reaction for the antibodies anti- TNF and CD138 in the endometriosic group. The control group revealed a negative reaction for all immunohistochemical dye. The immunohistochemical results were confirmed by Western blotting and real time PCR CONCLUSIONS Results demonstrated, in the eutopic endometrium from women with endometriosis, an increased expression of cytokines known to be involved in subclinical chronic endometritis. The presence of a chronic pro inflammatory endometrial environment could concur to explain the poor reproductive potential and the other symptoms associated to this complex disorder.