Immunohistochemical detection of heparanase-1 expression in eutopic and ectopic endometrium from women with endometriosis

ObjectiveTo investigate the expression of heparanase-1, an endoglycosidase that degrades heparan sulfate proteoglycans, in eutopic and ectopic endometrial tissues from women with endometriosis.DesignAn immunohistochemical study.SettingAcademic research laboratory and a private infertility clinic affiliated with a university medical center.Patient(s)Premenopausal women undergoing laparoscopy for endometriosis.Intervention(s)None.Main Outcome Measure(s)Expression of heparanase-1 analyzed by immunohistochemical staining in 91 eutopic and 14 ectopic endometrial specimens.Result(s)We found that 17% (4/24) of the eutopic endometrial specimens in the early proliferative phase and 32% (9/28) of the samples in the midproliferative phase were heparanase-1 positive. However, ≥80% of eutopic endometrial specimens at late proliferate phase and at luteal phase were heparanase-1 positive. Twelve of 14 ectopic endometriotic specimens stained heparanase-1 positive. Comparison of heparanase-1 expression in paired eutopic and ectopic endometrial tissues revealed that 5 of 6 ectopic specimens in the early proliferative phase were heparanase-1 positive, whereas only 1 eutopic specimen was heparanase-1 positive. In comparison with our recent study of heparanase-1 expression in normal endometrium, we found that there was no significant difference in heparanase-1 expression in the eutopic endometrium from women with or without endometriosis.Conclusion(s)Heparanase-1 was differentially expressed in the eutopic endometrium in the different menstrual phases. Heparanase-1 was highly expressed in the ectopic endometriotic lesions regardless of their menstrual phases, suggesting that the local environment is responsible for increased heparanase-1 expression.