MORPHOLOGICAL AND IMMUNOHISTOCHEMICAL FEATURES OF PLACENTAL DAMAGE DUE TO THE INCORPORATION OF 137Cs

Abstract

Objective: to investigate the morphological and immunohistochemical features of placental damage due to the incorporation of 137Cs depending on the scenario of pregnancy completion. Materials and methods. The study material consisted of placentas from 60 women with reproductive losses in anamnesis and signs of termination of the current pregnancy (first group) and placental samples from 30 women with an uncomplicated gestation and an unencumbered anamnesis (control group). The detailed study required the distribution of placental samples from the first group into subgroups. Subgroup 1a included 38 placentas from women who gave birth at 37–40 weeks, despite signs of termination of the current pregnancy. Subgroup 1b – placentas of 13 women who gave birth at a gestation period of 28–36 weeks + 6 days. Subgroup 1c – 9 placental samples from women who gave birth at a gestation period of 22–27 weeks + 6 days. The volumetric activity of the 137Cs in the placentas was measured using β-spectrometer. The histology of the placenta was studied using a standard technique. The following expressions were studied in placenta: CD31 / PECAM-1, CD45 / T200 / LCA, CD56 / NCAM-1, CEA / CD66e Ab-2, Vimentin, using indirect streptavidin peroxidase detection method. Results. Placentas accumulate 137Cs. The different volumetric activity of the isotope correlates with scenarios of pregnancy. Due to the action of incorporated 137Cs with a specific mass of more than 1.1 Bq/kg, placental dysfunction develops. The consequences of placental dysfunction depend on the volumetric activity of the 137Cs and the preservation of adaptive and compensatory reactions in the placenta. Morphological and immunohistochemical features of placental damage to incorporated 137Cs were established, depending on the scenario of completion of pregnancy. A marker of unfavorable completion of pregnancy is the expression of a carcinoembryonic antigen (CEA) in the placenta. Conclusions. Premature termination of pregnancy (PTP) is a multifactorial pathology associated with pathological changes in immune and neuroendocrine regulation and hereditary, infectious, and environmental factors that disrupt the adaptation mechanisms in the mother-placenta-fetus system. Intraplacental irradiation of 137Cs is one of the factors in the multifactorial nature of reproductive losses. As a result of intraplacental irradiation of 137Cs, the architecture of the placenta is disturbed, the activity of pro-inflammatory cytokines CD45 and CD56 increases, and the coagulation cascade is activated. Extreme effects depend on the volumetric activity of the isotope incorporated in the placenta and the organ’s compensatory capacity. Accumulation of up to 1.0 Bq/kg 137Cs does not affect the course of gestation. Internal irradiation with an activity of 4.5–10.4 Bq/kg 137Cs triggers late preterm labor. The nature of the damages corresponds to the category of «lesion of the maternal stroma» of the placenta. The volumetric activity of 137Cs over 10.4 Bq/kg is a probable cause of early preterm labor and antenatal fetal death. At the same time, the maternal and fetal structures of the placenta suffer damage. Expression of vimentin is a marker of placental destruction due to internal irradiation of 137Cs with a specific gravity of more than 4.5 Bq/kg. Expression of CEA in the structures of the placenta of women with PTP is a unique find and marker of premature birth and antenatal fetal death with intraplacental irradiation of 137Cs with an activity of more than 4.5 Bq/kg. Key words: pregnancy, placenta, reproductive losses, 137Cs, CD45 / T200 / LCA, CD56 / NCAM-1, CD31 / PECAM-1, Vimentin, CEA / CD66e Ab-2.

Features Functioning of the Detoxification System at the Threat Termination of Pregnancy as a Consequence of Accumulation of 137cs

“…The most common cause of reproductive losses is placental dysfunction [7,21], which in pregnant women of the fi rst group was formed under the infl uence of internal irradiation 137 Cs [8,9]. Of course, the decisive factor was the absorbed dose of radiation.…”

“…The risk of pregnancy loss after fi rst miscarriage is 13-17 %, second to 24 %, third to 30 %, and fourth to 40 % [4]. The factors of pregnancy failure are various [1][2][3][4][5][6][7][8][9]. In almost 80 % of women, termination of pregnancy occurs due to a violation of adaptation in the «mother-placenta-fetus» system under the influence of immune and endocrine deregulation [1-3, 6, 7].…”

“…Despite a wide range of known factors, it is not always possible to establish the reason for termination of pregnancy in 41.2 % of women [1,2,5]. There is no doubt about the connection between miscarriage and environmental and social factors of modern life [2,[6][7][8][9].…”

“…Internal radiation is one cause of reproductive losses [8,9]. Internal radiation suppresses cell division and tissue diff erentiation in the pre-implantation and implantation period, as well as during placentation, increasing the risk of death of the embryo and fetus.…”

“…An excess of free radicals affects reproduction. Internal irradiation 137 Cs disrupts the placental architecture, synthesis of hormones, and uteroplacental and placental-fetal microcirculation [8,9]. Pregnancy scenarios depend on the activity and speed removal of 137 Cs from the body, preservation of compensatory capabilities of the placenta, and proper functioning of the antioxidant system.…”