Extracellular vesicle‐mediated endothelial apoptosis and EV‐associated proteins correlate with COVID‐19 disease severity

Coronavirus disease‐2019 (COVID‐19), caused by the novel severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2), has lead to a global pandemic with a rising toll in infections and deaths. Better understanding of its pathogenesis will greatly improve the outcomes and treatment of affected patients. Here we compared the inflammatory and cardiovascular disease‐related protein cargo of circulating large and small extracellular vesicles (EVs) from 84 hospitalized patients infected with SARS‐CoV‐2 with different stages of disease severity. Our findings reveal significant enrichment of proinflammatory, procoagulation, immunoregulatory and tissue‐remodelling protein signatures in EVs, which remarkably distinguished symptomatic COVID‐19 patients from uninfected controls with matched comorbidities and delineated those with moderate disease from those who were critically ill. Specifically, EN‐RAGE, followed by TF and IL‐18R1, showed the strongest correlation with disease severity and length of hospitalization. Importantly, EVs from COVID‐19 patients induced apoptosis of pulmonary microvascular endothelial cells in the order of disease severity. In conclusion, our findings support a role for EVs in the pathogenesis of COVID‐19 disease and underpin the development of EV‐based approaches to predicting disease severity, determining need for patient hospitalization and identifying new therapeutic targets.