The Maternal-Fetal Interface Fibrin Deposition and Expression of FGL2 in the Placenta of Preeclampsia and Fetal Growth Restriction

Abstract

We aimed to assess fibrin deposition in placentas of patients with preeclampsia (PE) with fetal growth restriction (FGR) and the relationship with fibrinogen-like protein 2 (FGL2). In this case-control study, pregnant women with PE (n=48), PE with FGR (n=44), FGR (n=43), and healthy pregnant women (n=43) at term gestation were recruited. We compared the baseline characteristics, blood coagulation parameters, and placenta characteristics. Masson's trichrome staining was used to categorize 2 types of fibrinoid. FGL2 expression was examined by immunohistochemical staining. The PE+FGR placentas showed more obvious fetal and maternal vascular malperfusion and maternal-fetal interface fibrin deposition when compared with the others. Increased fibrin-type and matrix-type fibrinoids were found in the placenta of the PE+FGR group when compared with the controls. FGL2 was localized in the junction of these 2 types of fibrinoid, as well as extravillous trophoblastic layers and decidual stromal cells. The PE+FGR group had significantly lower FGL2 expression levels. Placental vascular malperfusion with massive maternal-fetal interface fibrin deposition was found in PE with FGR. We report the characteristic colocalization of 2 types of placental fibrinoid deposition and FGL2 immunoreactivity and, therefore, help in elucidating the mechanisms in the pathology of PE with FGR.