Structural organization of the umbilical cord vascular connective tissue in cytomegalovirus infection in the third trimester of pregnancy

Abstract

Aim. To study the structural organization of the connective tissue of the vein wall of the umbilical cord vessels from seropositive to cytomegalovirus (CMV) women with an exacerbation of infection in the third trimester of pregnancy. Materials and methods . There was done the study of the activity of glycosaminoglycans in the connective tissue of the vascular wall of the vein and the content of elastase in the umbilical cord homogenate obtained during childbirth at 38-39 weeks of pregnancy from 35 CMV-seropositive women with an exacerbation of infection in the third trimester of pregnancy (the main group), and from 32 CMV-seronegative women (the control group). The material for the histo-chemical study was the sections of the venous wall of the umbilical cord vessels adjacent to the placenta. The activity of glycosaminoglycans was studied by Steedman, the content of elastase was studied by enzyme immunoassay. Results. The study of umbilical cord tissue extracts revealed a 1.3-fold increase in immune enzyme elastase indices (p<0.001) in the group of CMV-seropositive women with an exacerbation of infection in the third trimester of pregnancy. Histochemical examination of the same umbilical cords revealed an increase in the intensity of the reaction to acidic glycosaminoglycans located in the subendothelial layer, in the intermuscular layers of connective tissue, in the cytoplasm of fibroblasts and in the smooth muscle cells of the inner layer of the umbilical vein muscles. The most pronounced reaction to glycosaminoglycans was detected in the collagen fibers of the subendothelial layer of the umbilical vein. In addition, areas of pronounced destruction and desquamation of endothelial cells were detected. The connective tissue of the subendothelial layer was characterized by the disappearance of the tortuosity of collagen fibers with signs of atrophy and a decrease in the number of cell elements in the vascular wall. Conclusion. Based on the results of the study, it was shown that the exacerbation of CMV infection in the third trimester of pregnancy is characterized by an increase in the enzymatic activity of elastase and the production of acid glycosaminoglycans in the connective tissue of Wharton’s jelly, which leads to the destruction of collagen fibers and disturbance of the framework and elasticity of the vascular wall of the umbilical vein.