COVID-19 induces a hyperactive phenotype in circulating platelets

ABSTRACT

BackgroundCoronavirus 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 plateletneutrophil 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. EssentialsO_LIRoutine platelet-related clinical blood parameters (MPV, PNR) are associated with disease severity in COVID-19. C_LIO_LIAgonist-induced ADP release is dramatically higher in COVID-19 patients compared with non-COVID-19 hospitalized patients. C_LIO_LICirculating levels of PF4, sP-selectin levels and TPO are significantly elevated in COVID-19. C_LIO_LIIdentification of a hyperactive platelet phenotype may warrant re-evaluation of current thrombotic prevention strategies in COVID-19 treatment. C_LI