HEMOSTATIC ABNORMALITIES IN COVID-19: UNDERLYING MECHANISMS AND CLUES TO TREATMENT Do we Really See a “Storm” Never Seen Before?

Despite relatively short time since Covid-19 infection has appeared in the world, enormous amount of literature data (more than 20 000 articles currently (mid-June)) is available on PubMed. Those data, together with our own experience at Karolinska University Hospital point towards hemostatic abnormalities in significant number of severe patients. Majority of those patients experience persistent hypercoagulation with massively increased D-dimer and fibrinogen. As a consequence, clinical thrombotic events, including venous thromboembolism (VTE) are common in Covid-19 patients and it seems that increased anticoagulant prophylaxis may be beneficial for severe (ICU/mechanical ventilation) patients. The lungs are most severely injured by the virus and that the potential underlying mechanism is a crosstalk between inflammation/complement and hemostasis. It is important to emphasize that the importance of hemostatic abnormalities in Covid-19 patients should not be overestimated since thromboembolic phenomena are, to a similar extent, present in other influenza and severely ill patients