Thrombocytopenia and thrombosis in hospitalized patients with COVID-19.

As our understanding on coronavirus disease 2019 (COVID-19) deepens, it is increasingly recognized that COVID-19 is more than a respiratory condition. Thrombocytopenia and thromboembolic complications are a composite factor associated with critical COVID-19 and increased mortality. Immune-inflammation-mediated destruction, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection per se and increased consumption are proposed to be responsible for thrombocytopenia. Multiple concomitant conditions or results caused by SARS-CoV-2 infection are high risk factors for thrombosis. Recently, platelet activation and platelet-mediated immune inflammation induced by SARS-CoV-2 infection were also found to be the contributors to the thrombosis in COVID-19 patients. In addition to thrombus scoring system, D-dimer is an excellent indicator for monitoring thrombosis. COVID-19 patients with high risk for thrombosis should be subjected to early thromboprophylaxis, and prolonged activated partial-thromboplastin time should not be a barrier to the use of anticoagulation therapies in the control of thrombosis in COVID-19 patients.