TH1/TH2 cytokine profile in serum and peritoneal fluid and role in the pathogenesis of Endometriosis

Abstract. Objective. Endometriosis is a disorder characterised by presence and growth of endometrial tissue outside the uterus. The peritoneal fluid (PF) of women with endometriosis undergoes a local inflammatory-reparative phenomena with involvement of a number of activated cells as peripheral blood mononuclear cells, peritoneal macrophages, endometriotic cells and their soluble products. They all realise a favourable microenvironment for the implantation of the endometriotic tissue and the progression of the disease. In the present study we evaluated the levels of TH1 cytokines, as IL-12, IFN-gamma and TNF-alpha, TH2 cytokines, as IL-10 and TGF-beta, and of chemokines, as IL-8 and MCP-1, in PF and in Serum (S) of women with endometriosis at minimal, mild and severe stages to compare their behaviour and role in both biological fluids. Design and method. 40 patients attending our observation for infertility were examined. S samples were obtained from peripheral blood before anaesthesia and PF samples were collected at the time of laparoscopy. Both biological fluids were examined for cytokines and chemokines by ELISA assays. Statistical analysis was performed according to Fisher’s exact test (ANOVA). Results. Our results showed that S and PF levels of IL-12, IFN-gamma and TNF-alpha were very high at the minimal stage and decreased significantly (p<0.001) with the severity of the disease. IL-10 and TGF-beta levels significantly (p<0.001) increased with the severity of the disease, particularly in the PF. S levels of IL-8 and MCP-1 were significantly (p<0.001) higher at minimal endometriosis and decreased with the severity of the disease, whereas in PF they enhanced significantly (p<0.001) from minimal to severe stage. Conclusion. These results showed a prevalence of TH1-cytokines and then of inflammatory phenomena in S and PF of patients with minimal endometriosis; on the contrary, S and PF TH2-cytokines increased with the severity of the disease, when triggering reparative phases. The chemokines behaved in a different way in S and PF, indicating the role of exaggerated autocrine secretion by peritoneal macrophages as well as endometriotic cells in the pathogenesis of endometriosis.