Immunocytochemical markerprofile of endometriotic epithelial, endometrial epithelial, and mesothelial cells: a comparative study.

A comparative immunocytochemical study was performed on endometriotic epithelial versus endometrial epithelial and normal mesothelial cells in order to obtain further evidence for either the endometrial implantation or mesothelial metaplasia theory. The three cell types could not be distinguished by keratin subtyping, using monoclonal antibodies (MAbs) to keratins 5, 7, 8, 14, 18, and 19. The epithelial markers HMFG-2 and BW 495/36, and a newly developed MAb NEND-3 (against endometrial cells) discriminated between generally negatively reacting mesothelial cells and positively reacting endometrial and endometriotic epithelial cells. The MAb NEND-3 appeared to be specific for endometrial (and endometriotic) epithelial cells since no reactivity with other epithelial cell types was found. Typing with MAbs against ovarian carcinoma related antigens (OV-TL 3, OV-TL 10 and OC 125) did not permit sufficient distinction. The marker profile of cultured endometrial, endometriotic and mesothelial cells confirmed the immunocytochemical findings on frozen sections. Although the data are consistent with the endometrial implantation theory, mesothelial metaplasia can not be excluded with regard to the histogenesis of endometriosis since metaplastic mesothelium may express different antigen markers.