Histological Study of Human Placenta in Preeclampsia and the Role of Decidual Natural Killer Cells and Macrophages in its Pathogenesis

Abstract

Background: Preeclampsia (PE) is a hazardous pregnancy condition, if untreated can result in serious complications to the mother and the fetus.Aim of work: Investigating the histological changes of human placenta in PE and the involvement of natural killer (NK) cells and macrophages in its pathogenesis.Subjects and Methods: Forty pregnant women were included; 20 were normal clinically and considered the control (group I) and the other 20 were included in PE (group II). Blood samples were taken just before delivery to assess serum interleukins (IL)-10 and -12 and transforming growth factor (TGF)-β1. Placental sections were stained with H&E, Mallory's trichrome and immunohistochemically with Bcl-2, vascular endothelial growth factor (VEGF), CD56 and CD68. Then morphometric and statistical studies were done.Results: Group II (PE) showed significantly decreased IL-10 and significantly increased IL-12 and TGF-β1 compared to group I. It also presented different histological alterations in placental sections mainly in the chorionic plates and villi. There was significant increase in area percent of collagen fibers and VEGF, and in the number of syncytial knots, CD56 positive decidual NK cells and CD68 positive decidual macrophages. But there was significant decrease in the area percent of Bcl-2 immunoexpression.Conclusion: Preeclampsia is associated with marked inflammatory and immune responses, and decidual NK cells and macrophages are highly imperative cells in its pathogenesis