IMMUNOLOGICAL AND PATHOMORPHOLOGICAL ASPECTS OF EARLY AND LATE PREECLAMPSIA

Abstract

Preeclampsia (PE) is one of the most common complications of pregnancy, and it can be after 20 weeks of gestation. It ends only with a complete dissection of afterbirth. Traditionally, PE is subdivided into the early one, taking place through 34 weeks of pregnancy (EOPE) and the late one, which is after 34 weeks of gestation (LOPE). Clinical manifestations are similar in both cases however, risk factors and the severity of PE are different . It has been established that EOPE is determined by impaired trophoblast invasion and transformation of the spiral arteries of the uterus in early pregnancy, and late onset of PE is associated with oxidative stress of syncytiotrophoblast, which occurs secondarily, with limited gas exchange and insufficient intake of nutrients. Numerous studies have noted a significant contribution of immune responses to the pathogenesis of preeclampsia, however, the state of B-lymphocytes in EOPE and LOPE has not been studied. A comprehensive assessment of the condition of women with early (up to 34 weeks of pregnancy inclusive) and late (after 34 weeks) development of preeclampsia was carried out, taking into account clinical and anamnestic characteristics, the peculiarities of the formation of the structural components of the placenta, as well as determining the nature of differentiation and functional activity of B-lymphocytes. In peripheral venous blood, the content of CD19+, CD20+, CD19+CD27+IgD±, CD19+CD20- CD38+, CD20+CD5+-cells and serum levels of IL-5, IL-9, IL-13 were examined. Morphological examination included gross description, organometry, survey histology, and transmission electron microscopy. In the group of women with early preeclampsia in history, there were more often perinatal losses, premature births and medical abortions, and in the current pregnancy, intrauterine infection, oligohydramnios, placental insufficiency and fetal growth retardation. With late preeclampsia, metabolic syndrome, anemia, and a history of arterial hypertension were more often observed. In the peripheral blood of all women with preeclampsia, there was an increase in the content of CD20+CD5+-cells in comparison with those in uncomplicated pregnancy, more pronounced in the late onset of preeclampsia. Only in women with early preeclampsia blood levels of CD19+CD20- CD38+ and CD19+CD27+IgD±-cells, IL-5, IL-9 and IL-13 increased. Studies of the placenta in early preeclampsia indicated impaired implantation and pathological placentation with the development of primary placental insufficiency, which becomes chronic. In late preeclampsia, the development of placental insufficiency was determined by chronic disorders of maternal and fetal hemocirculation with increased deposition of fibrin and fibrinoid in the basal lamina and in the zones of villous epithelium necrosis. The study showed that the timing of the manifestation of preeclampsia is determined by the action of factors of the clinical history, structural rearrangements in the placenta and immune responses of B-lymphocytes are closely interrelated.

Keywords

• early and late preeclampsia
• placenta
• peripheral blood
• b-lymphocytes