The involvement of multifunctional TGF-β and related cytokines in pathogenesis of endometriosis

Purpose: Transforming growth factor beta (TGF-beta) is one of the major immune and inflammation factors responsible for regulating cell proliferation, differentiation, angiogenesis, and immune responses. Deregulated TGF-beta activity, especially its influence in peritoneal cytokine cross-talk, has been implicated in pathologies of endometriosis. The aim of this study was to determine whether TGF-beta could be involved in the pathogenesis of endometriosis. For this purpose, we evaluated concentrations of TGF beta 1, TGF-beta 2, TGF-beta 3 and interleukin (IL)-1 beta, IL-6, IL-10, IL-17, IL-21 and IL-22 in peritoneal fluid (PF) and serum of women with endometriosis. Methods: A total of 66 women of reproductive age were involved in the study, 51 endometriosis patients, and 15 women from the control group. PF and serum levels of all cytokines were measured with ELISA in women with or without endometriosis. Results: Higher PF and serum levels of TGF-beta 1, TGF-beta 2, TGF-beta 3, presented also as a total TGF-beta in women with endometriosis compared to control were observed. The biggest increase was measured in the case of TGF-beta 1. The higher levels of IL-1 beta, IL-6, IL-10, and IL-17 in PF and serum of endometriosis women than control was observed. Higher PF levels of studied parameters in comparison with serum levels were found. Conclusions: In endometriosis, TGF-beta could affect differentiation of T helper (Th) cells, hence produce more IL-17 and IL-10 to PF and might have an indirect influence on inflammation, which is associated with higher IL-1 beta and IL-6 levels. In consequent, TGF-beta in peritoneal fluid may promote an environment favorable to ectopic lesion formation.