PATHOGENETIC ASPECTS OF POST-COVID-19 COMPLICATIONS IN THE BLOOD COAGULATION SYSTEM

Disorders in the blood coagulation system play an important role in the pathogenesis and clinical manifestations of COVID-19 both during the acute phase of the disease and in the post-infectious period. The coronavirus disease is associated with a high risk of thrombotic and thromboembolic complications due to a prolonged state of hypercoagulation, which can occur even after recovery. Despite the extremely large amount of scientific data, the pathophysiological aspects of SARS-CoV-2 infection remain uncertain. The presented review summarizes the results of modern scientific research on pathological changes in the hemostasis system that can occur against the background of the transferred coronavirus disease, and considers the main mechanisms of the development of COVID-19-associated coagulopathies. From scientometric databases PubMed, Scopus, Web of science, ScienceDirect, Google Scholar, etc. the latest publications devoted to this issue were selected and analyzed. Hemostasis is a dynamic, tightly regulated process which is provided by three closely interrelated links: coagulation, anticoagulation, and fibrinolytic. Activation of the coagulation cascade and the platelet link of hemostasis, which causes a prothrombotic state in convalescent patients with COVID-19, is primarily associated with dysregulation of the renin-angiotensin system, a long-term local and systemic inflammatory reaction, an increase in the immune response due to the release of pro-inflammatory mediators that interact with platelets, stimulate the expression of tissue factor, suppress the fibrinolytic system and lead to dysfunction of the endothelial cells of blood vessels, triggering thrombogenesis. Understanding the pathogenetic mechanisms of post-COVID-19 complications and monitoring the main markers of hemostasis (level of D-dimer, fibrinogen, prothrombin time, platelet count, etc.) are important for the timely detection of disorders in the blood coagulation system, and make it possible, depending on the clinical situation, to take timely measures for their correction at various stages of pathology development.