Cellular and molecular mechanisms in COVID-19 coagulopathy: role of inflammation and endotheliopathy

INTRODUCTION: Coronavirus 2 (CoV-2) infection or coronavirus disease 2019 (COVID-19) is frequently associated with microvascular thrombosis.The microthrombosis in COVID-19 is the result of the interplay between inflammation and endotheliopathy. Elevated interleukin-6 (IL-6) characterizes COVID-19 inflammation resulting in endotheliopathy and coagulopathy marked by elevated D-dimer (DD). Aim of this study is to identify and to describe the coagulation changes in 100 moderate COVID-19 patients having lung involvement and to determine the association of coagulopathy with the severity and prognosis. METHODS: Inflammation, endothelial and coagulation molecules were measured in moderate and mild disease. RESULTS: IL-6 and tumor necrosis factor-α (TNF-α) and tissue factor (TF), von Willebrand factor (VWF), and tissue factor pathway inhibitor (TFPI) significantly increased in moderate disease as well as D-dimer, thrombin antithrombin complex (TAT), Fibrinogen (Fib), platelet factor-4 (PF4), β-thromboglobulin (β-TG), P-selectin, and platelet adhesion. Shortened clotting time (CT) and clot formation time (CFT), high maximum clot firmness (MCF) and low LY at 30 min were present in 100% of moderate COVID-19 patients compared with mild COVID-19 patients. CONCLUSIONS: These findings demonstrate that moderate COVID-19 has a profound inflammation associated with severee ndotheliopathy and intense coagulation activation uncontrolled by TFPI. Attention should be paid to coagulopathy in COVID-19. Closely monitoring of coagulation and application of appropriate anticoagulation may improve the prognosis of moderate COVID-19 and to prevent the progression to severe COVID-19 disease.