Evaluation of erythrocyte band 3 phosphotyrosine level, glutathione content, CA-125, and human epididymal secretory protein E4 as combined parameters in endometriosis

Objective: To investigate the biochemical parameters of the erythrocyte response to diamide-induced oxidative stress, alone or as adjuncts to serum values of CA-125 and human epididymal secretory protein E4 (HE4), in the diagnosis and study of endometriosis. Setting: University of Padova. Design: Prospective study. Patient(s): Forty-five patients of reproductive age undergoing laparoscopy. Intervention(s): All women were studied for endometriotic foci during laparoscopic surgery. Forty-one had laparoscopically and histologically confirmed endometriosis, and four did not. Twenty women with confirmed endometriosis were reassessed 1-4 months later. Main Outcome Measure(s): CA-125 and HE4 and two new parameters evaluated in erythrocytes after diamide-induced stress, that is, band 3 tyrosine phosphorylation (Tyr-P) level and decrease in total glutathione content (Delta GSH), were assessed in all patients. Result(s): In association with serum CA-125 levels but not with HE4, diamide-related erythrocyte band 3 Tyr-P and DGSH were significantly higher in patients with endometriosis and were able to discriminate with high sensitivity and specificity between patients before and after surgery. Conclusion(s): Endometriosis is associated with an increase in systemic oxidative stress, affecting the antioxidative defenses of circulating erythrocytes. All related implications, including evaluation of other oxidative stress-related changes, warrant further study. (Fertil Steril (R) 2010;94:1616-21. (C) 2010 by American Society for Reproductive Medicine.)