Altered Expression of Human Leukocyte Antigen G (HLA‐G) on Extravillous Trophoblasts in Preeclampsia: Immunohistological Demonstration With Anti‐HLA‐G Specific Antibody “87G” and Anti‐cytokeratin Antibody “CAM5.2”

Abstract

PROBLEM: Human leukocyte antigen-G (HLA-G) is suggested to be at play in the materno-fetal immune relationship during pregnancy. In the light of current concept that disruption of the materno-fetal immune relationship could account for several complications of pregnancy, including preeclampsia, we asked whether the expression of HLA-G protein on the trophoblasts is altered in preeclampsia. METHOD: The presence of HLA-G protein in the extravillous trophoblasts in placenta obtained from five preeclamptic patients and seven uncomplicated pregnant women was determined by means of an immunohistochemical technique. RESULTS: All of the extravillous trophoblasts, which were stained for cytokeratin, were stained for HLA-G protein in every woman with an uncomplicated pregnancy. In contrast, clusters of extravillous trophoblasts were insularly devoid of the staining for HLA-G in all the preeclamptic patients. CONCLUSION: The attenuated expression of HLA-G protein on the extravillous trophoblasts could be at play in the pathophysiology of preeclampsia.