Change in platelet indices in patients with Coronavirus disease-2019 (COVID-19): A reflection of platelet activation and contribution to immunothrombosis?

Mezgebe, Michael; Jacobson, Barry Frank; Mayne, Elizabeth Sarah; Louw, Susan

In December 2019, several cases of pneumonia of unknown aetiology were reported in Wuhan, China. The causative Coronavirus was subsequently isolated and named the Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) and the disease, Coronavirus disease-2019 (COVID-19).1 COVID-19 related coagulopathy is a poor prognostic feature and reflects an underlying pathological process termed immunothrombosis.2 This process differs from infection-related disseminated intravascular coagulation (DIC) as it manifests primarily with thrombosis while thrombocytopenia and bleeding remain modest.3 The coagulation activation in COVID-19 relates to endothelial dysfunction, complement activation and ensuing cytokine storm with contributions from secondary infections and organ dysfunction.1,2 D-dimer values above 0.5 mg/L signifies poor patient outcomes.