Role of neutrophils, platelets and extracellular vesicles and their interactions in Covid-19-associated thrombopathy.

Caillon, Antoine; Trimaille, Antonin; Favre, Julie; Jesel, Laurence; Morel, Olivier; Kauffenstein, Gilles

COVID-19 pandemic extended all around the world causing millions of deaths. Beside the acute respiratory distress syndrome, a large number of severe COVID-19 patients develop thrombo-embolic complications associated to multi organ failure and death. Here, we review evidences for the contribution of neutrophils, platelets and extracellular vesicles (EV) to the thromboinflammatory process in COVID-19. We discuss how the immune system, influenced by pro-inflammatory molecules, EVs and neutrophil extra-cellular traps (NETs), can be caught out in patients with severe outcomes. We highlight how the deficient regulation of the innate immune system favors platelet activation and induces a vicious cycle amplifying an immuno-thrombogenic environment associated with platelet/NET interactions. In the light of these considerations, we discuss potential therapeutic strategies underlining the modulation of purinergic signaling as an interesting target.