Paracrine changes in the peritoneal environment of women with endometriosis

During the past decade, macrophage-derived substances such as prostanoids, cytokines, growth factors and angiogenic factors have been detected in the peritoneal fluid of women with endometriosis. In particular, growth-promoti ng and angiogenic factors are considered to be substantially involved in th e pathogenesis of endometriosis. In this study, vascular endothelial growth factor (VEGF), transforming growth factor beta (TGF-beta) and intercellula r adhesion molecule 1 (ICAM-1), substances recently detected in the periton eal fluid of women with endometriosis, were assessed with regard to their c oncentrations in different stages of endometriosis and changes of the perit oneal paracrine activity after medical treatment with a gonadotrophin relea sing hormone agonist (GnRHa). Peritoneal fluid was obtained from patients w ith endometriosis during laparoscopy before and after a 4-month treatment w ith a GnRHa. VEGF; TGF-P and ICAM-1 could be detected in all women presenti ng with various stages of active endometriosis. After GnRHa therapy, all pa tients showed significant decreases in mean concentrations of VEGF (194 +/- 77 pg/ml), TGF-beta (902 +/- 273 pg/ml) and ICAM-1 (157 +/- 52 ng/ml). Pat ients with stage III and IV endometriosis (according to the rAFS score) had much higher concentrations of VEGF and TGF-beta before treatment compared with those patients with mild endometriosis (rAFS stages I and II). The mos t striking decrease in concentration was for TGF-beta, from 902 pg/ml befor e to 273 pg/ml after therapy, These results indicate an important role for paracrine activity in the establishment and maintenance of endometriosis, I ndeed, treatment with a GnRHa may reduce paracrine activity in the peritone al cavity via hypo-oestrogenism and provide proof of successful therapy.