Thrombosis and coagulopathy in COVID-19: An illustrated review.

This illustrated review discusses the haemostatic changes seen in patients with severe coronavirus disease 2019 (COVID-19) infection and their possible causes. We discuss the crosstalk between inflammation and coagulation resulting in high levels of acute-phase proteins, very high levels of D-dimers, and absence of disseminated intravascular coagulation seen in patients with severe COVID-19. There appear to be high rates of venous thromboembolism and also, what has been poorly described before in acute lung injury, a high rate of pulmonary immunothrombosis (thrombosis secondary to inflammation).

There are marked increases in coagulation proteins in patients with severe coronavirus disease 2019 (COVID‐19) infection, consistent with a profound acute‐phase response.

D‐dimer levels are extremely high and reflect activation of fibrinolysis systemically and also in the lungs.

Disseminated intravascular coagulation is rarely seen in severe COVID‐19 infection outside of preterminal multiorgan failure.

Thrombosis rates appear high due to venous thromboembolism and pulmonary immunothrombosis.