Peritoneal fluid proteome in women with different ASRM stages of endometriosis

Objective. Endometriosis has a wide range of severity but molecular factors associated with variable extension of the disease have not been widely investigated. The present study compares the peritoneal fluid (PF) proteome of 109 women with endometriosis and different disease stage as defined by the American Society for Reproductive Medicine (ASRM). Methods. PF samples were subjected to two-dimensional gel electrophoresis; protein spots of interest were identified by liquid chromatography tandem mass spectrometry. Results. Over 470 protein spots were analyzed. One isoform of haptoglobin α chain, α-1b-glycoprotein and one unknown protein had higher expression in PF of women with ASRM stage I-II endometriosis. Four isoforms of α1-antitrypsin, three isoforms of α-1b-glycoprotein, one isoform of S100-A8 and serotransferrin had higher expression in PF of women with ASRM stage III-IV disease. Conclusions. Several protein isoforms have different expression in PF of women with ASRM stage I-II endometriosis than in those with ASRM stage III-IV disease; most of these molecules are involved in inflammation and immune response.