THE PERITONEAL ENVIRONMENT IN ENDOMETRIOSIS

The local environment of peritoneal fluid (PF) surrounding the endomet riotic implant is immunologically dynamic and links the reproductive a nd immune systems, Peritoneal fluid contains a variety of free floatin g cells, including macrophages, mesothelial cells, lymphocytes, eosino phils and ma,st cells, Macrophages are attracted to the peritoneal env ironment more abundantly than any other cell type, These scavengers pr omote cellular growth and viability through secretion of growth factor s and cytokines, It is now becoming evident that cytokines pla:ii an i mportant role in reproduction at various levels, including gamete func tion, fertilization and embryo development, implantation and postimpla ntation survival of the conceptus, Peritoneal fluid has been shown to affect negatively ovum capture by the fimbria, sperm survival, spermat ozoon-oocyte interaction and embryonic development, We have recently i dentified the presence of two pro-inflammatory chemoattractant cytokin es for monocyte/macrophages (MCP-I) and for granulocytes (interleukin- 8, IL-8) in the PF, Concentrations of both IL-8 and MCP-1 are not only elevated in PF of women with endometriosis compared to those without endometriosis, but they are related to the severity of the disease, Ov er the past 70 years, at least a dozen theories have been proposed to explain the histogenesis and aetiology of endometriosis, It appears th at the aetiology is multifactorial, and today a composite theory of re trograde menstruation with implantation of endometrial fragments in co njunction with peritoneal factors to stimulate cell growth is the most widely accepted explanation for peritoneal endometriosis.