Proteomic analysis of peritoneal fluid in women with endometriosis.

This study aims to evaluate differences in the expression of proteins present in the peritoneal fluid (PF) of women with endometriosis and control subjects who underwent surgery for infertility or tubal sterilisation. PF samples were subjected to two-dimensional gel electrophoresis; protein spots of interest were identified by liquid chromatography tandem mass spectrometry. The mean number of PF protein spots per gel was similar in women with endometriosis and in the control group. No protein spot was consistently present in PF of women with endometriosis and absent in PF of control subjects. Similarly, no protein spot was uniquely present in PF of control subjects. 98 protein spots were consistently present in PF of women with and without endometriosis. Eleven protein spots had significantly higher expression in PF of women with endometriosis when compared with controls. These spots were identified as four isoforms of alpha2-Heremans Schmidt-glycoprotein, three isoforms of alpha1-antitrypsin, one isoform of protein S100-A8, one isoform of apolipoprotein A-1, one immunoglobulin (Ig) kappa chain C region, and one serum albumin precursor. Two protein spots had significantly lower expression in PF of women with endometriosis than in PF of controls; they were identified as alpha-1B-glycoprotein and pantophysin. Most of these molecules relate to immunological or inflammatory processes.