COVID-19 induces a hyperactive phenotype in circulating platelets

Abstract

AbstractBackgroundCoronavirus disease 2019 (COVID-19), caused by novel coronavirus SARS-CoV-2, has to date affected over 13.3 million globally. Although high rates of venous thromboembolism and evidence of COVID-19-induced endothelial dysfunction have been reported, the precise aetiology of the increased thrombotic risk associated with COVID-19 infection remains to be fully elucidated.ObjectivesHere, we assessed clinical platelet parameters and circulating platelet activity in patients with severe and non-severe COVID-19.MethodsAn assessment of clinical blood parameters in patients with severe COVID-19 disease (requiring intensive care), patients with non-severe disease (not requiring intensive care), general medical in-patients without COVID-19 and healthy donors was undertaken. Platelet function and activity were also assessed by secretion and specific marker analysis.ResultsWe show that routine clinical blood parameters including increased MPV and decreased platelet:neutrophil ratio are associated with disease severity in COVID-19 upon hospitalisation and intensive care unit admission. Strikingly, agonist-induced ADP release was dramatically higher in COVID-19 patients compared with non-COVID-19 hospitalized patients and circulating levels of PF4, sP-selectin and TPO were also significantly elevated in COVID-19.ConclusionDistinct differences exist in routine full blood count and other clinical laboratory parameters between patients with severe and non-severe COVID-19. Moreover, we have determined that COVID-19 patients possess hyperactive circulating platelets. These data suggest that abnormal platelet reactivity may contribute to hypercoagulability in COVID-19. Further investigation of platelet function in COVID-19 may provide additional insights into the aetiology of thrombotic risk in this disease and may contribute to the optimisation of thrombosis prevention and treatment strategies.EssentialsRoutine platelet-related clinical blood parameters (MPV, PNR) are associated with disease severity in COVID-19.Agonist-induced ADP release is dramatically higher in COVID-19 patients compared with non-COVID-19 hospitalized patients.Circulating levels of PF4, sP-selectin levels and TPO are significantly elevated in COVID-19.Identification of a hyperactive platelet phenotype may warrant re-evaluation of current thrombotic prevention strategies in COVID-19 treatment.