Pathomorphological and Molecular Biological Aspects of Blood Vessel Injury in COVID-19

Abstract

The coronavirus infection, COVID-19, caused by SARS-CoV-2 is associated not only with a wide range of respiratory syndromes, but also with a pronounced destructive effect on the blood vessels of the whole body. Age and concomitant pathology predispose to a more severe course of the disease. Endothelial damage, widespread vasculitis and thrombosis can be distinguished as general nonspecific pathomorphological changes developing in blood vessels under the influence of SARS-CoV-2. For the blood vessels of the lungs, in addition to alteration of the endothelium and thrombosis, angiogenesis of the cleaving (invagination) type was typical. The general mechanism of alteration of blood vessels and the development of vasculopathy is the direct cytopathic effect of the virus on endotheliocytes and immune-mediated damage to the endothelium, manifested by the development of endotheliitis, destruction of intercellular contacts of endothelial cells, their swelling and separation from the basement membrane, accompanied by endo- and perivascular inflammation. Molecular biological mechanisms of virus invasion involve various ways of its penetration into the cell and various forms of development of the inflammatory response with the participation of innate and acquired immunity reactions.