Serum Biomarker for Diagnosis of Endometriosis

Endometriosis is estimated to affect 10% of women during the reproductive years. The lack of a non-invasive diagnostic test significantly contributes to the long delay between onset of the symptoms and definitive diagnosis of endometriosis. This case-control study was conducted to identify specific endometriosis antigens using 2D gel analysis in women with endometriosis (n=5) and without endometriosis (n=5). Differentially expresses spots were analyzed using matrix-assisted laser desorption/ionization-time-of-flight/mass spectrometry (nanoLC-ESI-MS/MS) with MASCOT analysis, in order to identify the corresponding proteins. ELISAs were performed on a different cohort of endometriosis (n=120) and healthy patients (n=20) in order to confirm the differential expression of the identified proteins. ROC analysis of ELISA results confirmed the statistical significance of the differential expression for one of these proteins: Zn-alpha2-glycoprotein (P=0.019). We propose the analysis of the expression level of this protein in the serum as a new non-invasive diagnostic test for endometriosis. J. Cell. Physiol. 229: 1731-1735, 2014. © 2014 Wiley Periodicals, Inc.