Thrombotic storm, hemostasis disorders and thromboinflammation in COVID-19

The rate of thrombosis and disseminated intravascular coagulation (DIC) has been increasing in COVID-19 patients. Key features related to such condition include minimal or no risk of bleeding, moderate thrombocytopenia, high plasma fibrinogen as well as complement components level in the areas of thrombotic microangiopathy. The clinical picture is not typical for classic DIC. This review systematizes the pathogenetic mechanisms of hypercoagulation in sepsis and its extreme forms in patients with COVID-19. The latter consist of the thrombosis-related immune mechanisms, the complement activation, the macrophage activation syndrome, the formation of antiphospholipid antibodies, the hyperferritinemia, and the dysregulation of the renin-angiotensin system. Taking into consideration the pathogenetic mechanisms, the biomarkers had been identified related to the prognosis of the disease development. Patients with pre-existing cardiovascular disease and other risk factors, including obesity, diabetes, hypertension, and aging pose the peak risk of dying from COVID-19. We also summarize new data on platelet and endothelial dysfunction, immunothrombosis, and, as a result, thrombotic storm as essential components of COVID-19 severe features

Thrombotic microangiopathy, DIC-syndrome and COVID-19: link with pregnancy prothrombotic state

International audienceFor last months, humanity has faced a formidable unknown enemy, which is presented as a new coronavirus infection. Despite the fact that the causative agents of new diseases appear at a certain frequency and that the virus SARS-CoV-2 has certain common properties with its predecessors, at the moment we are dealing with a new unknown pathogenesis of the development of severe complications in patients with risk factors. A final understanding of pathological process mechanisms is the goal of the scientific community. Summarizing research data from different countries, it became obvious that in severe cases of viral infection, we are dealing with a combination of the systemic inflammatory response syndrome, disseminated intravascular coagulation and thrombotic microangiopathy (TMA). Thrombotic microangiopathy is represented by a group of different conditions in which thrombocytopenia, hemolytic anemia, and multiple organ failure occur. The article reflects the main types of TMA, pathogenesis and principles of therapy. The main participants in the process are described in detail, including the von Willebrand factor and ADAMTS-13. Based on the knowledge available, as well as new data obtained from patients with COVID-19, we proposed possible models for the implementation of conditions such as sepsis, TMA, and DIC in patients with severe new coronavirus infection. Through a deeper understanding of pathogenesis, it will be possible to develop more effective diagnosis and therapy

Laboratory monitoring of COVID-19 patients and importance of coagulopathy markers

The pandemic of a novel coronavirus infection COVID-19 has become a real challenge to the mankind and medical community and has raised a number of medical and social issues. Based on the currently available information on COVID-19 clinical cases, it follows that COVID-19 patients in critical condition exhibit a clinical picture of disseminated intravascular coagulation (DIC), septic shock with developing multiple organ failure, which justifies use of anticoagulant therapy in COVID-19 patients. In addition to isolating virus RNA from biological material and polymerase chain reaction diagnostics, use of simple and easily accessible laboratory blood markers is necessary for management of COVID-19 patients. If the activation of coagulation processes is sufficient enough, consumption of platelets and blood clotting factors can be diagnosed by laboratory methods as prolongation of routine blood clotting tests and increasing thrombocytopenia. Hyperfibrinogenemia, increased D-dimer level, prolonged prothrombin time, thrombocytopenia, lymphopenia, leukocytopenia, increased concentration of interleukin-6 and ferritin are observed in most COVID19 patients. The degree of increase in these changes correlates with severity of the inflammatory process and serves as a prognostically unfavorable sign. Here we discuss value of laboratory monitoring playing an essential role in such pathological crisis that contributes to patient screening, diagnosis as well as further monitoring, treatment and rehabilitation

Vaccine-induced immune thrombotic thrombocytopenia: definition, risks with different vaccines, and regulatory responses

After the vaccination campaign initiation in Europe and the UK, reports of rare cases of atypical thrombosis, including sinus vein thrombosis and splanchnic venous thrombosis, began to appear in association with the use of vector vaccines AstraZeneca (ChAdOx1) and Johnson & Johnson/Janssen. The syndrome called VITT (vaccine-induced immune thrombotic thrombocytopenia) manifested as thrombosis simultaneously with a decrease in platelet count, a significant increase in D-dimer levels and a detection of factor 4 platelet (PF4) antibodies. We present a detailed review of the epidemiology, pathogenesis, clinical presentation, diagnostics and treatment of VITT, which is by its nature an immune complication, similar to the processes occurring in heparin-induced thrombocytopenia (HIT). All international and national organizations and regulatory authorities, including experts in the field of thrombosis and hemostasis and the VITT expert council recommend continuing the prompt mass vaccination against COVID-19 as the only method that can reduce the incidence of severe cases, stop the spread of COVID-19 infection and the emergence of new dangerous mutations in the viral genome. Failure to vaccinate poses an incomparably greater risk of fatal thrombotic and inflammatory complications associated with infections, compared with the risks of extremely rare adverse events that can occur after vaccination. It should be noted that information on VITT, described as a sporadic phenomenon of an abnormal immune response to some variants of vaccines against COVID-19, cannot be translated to other vaccines (including registered in the Russian Federation) and even more cannot be a reason for refusal to use them