Abnormal peritoneal regulation of chemokine activation-The role of IL-8 in pathogenesis of endometriosis

Problem: Endometriosis is a chronic inflammatory disease associated with an impairment in immune response. Disorders in the peritoneal fluid and ectopic endometrium macrophage populations and their secretory products create a specific microenvironment inducing the development of the disease. The important factors involved in inflammation associated with endometriosis are chemokines, especially interleukin (IL)-8. For this reason, the current study briefly reviews the role of IL-8 in the pathogenesis of endometriosis. Method of study: A systematic review was done on all published studies that compared IL-8 expression and concentration in patients with and without endometriosis to evaluate their potential as biomarkers for the disease. Results: IL-8 induces chemotaxis of neutrophils and other immune cells; also, it is a potent angiogenic agent. Most researchers pointed to the increased peritoneal and serum IL-8 levels and showed correlation with the severity of the disease, size and number of the active lesions. IL-8 takes part in all processes during the development of the disease: adhesion, invasion, and implantation of ectopic tissue. Additionally, the chemokine plays a role in growth and maintenance of ectopic endometrial tissue directly affecting endometrial cell proliferation. IL-8 might also protect ectopic cells against death by apoptosis. Conclusion: It may act as an autocrine growth factor in the endometrium and promotes the vicious circle of endometrial cell attachment and, in consequence, may lead to a transformation from acute to chronic inflammation stage.