Uterus and endometrium: Immunohistochemical localization of extracellular matrix proteins in luteal phase endometrium of fertile and infertile patients

The lack of expression of certain components involved in celladhesion and migration is believed to contribute to endometrialdysfunction and implantation failure. The purpose of this studywas to investigate whether luteal phase endometrium in womenwith unexplained infertility differs, with respect to specificextracellular matrix (ECM) proteins, from endometrium of normalfertile women. A panel of monoclonal antibodies to collagentype IV, fibronectin and laminin was used to characterize thelocalization of ECM components in the different endometrialcompartments. Precisely timed endometrial biopsies obtainedat 4, 7, 10 and 13 days following the luteinizing hormone surgewere obtained from 22 normal fertile women (group 1) and 24women suffering from unexplained infertility (group 2). Paraffin-embeddedsections were labelled using the streptavidin-biotin alkalinephosphatase technique. In group 1, collagen type IV, fibronectinand laminin were absent from the luminal epithelium but presentin stromal cells and the basement membrane of glands and bloodvessels. In group 2, these components were absent from all endometrialregions using equivalent titres of antibody to those used ingroup 1. This suggests that the endometrium of women with unexplainedinfertility demonstrates defects in the distribution of certainECM glycoproteins. A possible consequence of this defect maybe implantation failure.