F2 and blood coagulation disease: International Society on Thrombosis and Haemostasis interim guidance on recognition and management of coagulopathy in COVID-19 defined the condition of coagulopathy in COVID-19 patients as prothrombin time (PT) prolongation above laboratory reference values (may vary depending on the reagent used), D-dimer ≥ 1.5 mg/L, fibrinogen < 2 g/L, or platelet count less than 100,000/μL [50].