Between inflammation and thrombosis - endothelial cells in COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing the current coronavirus disease (COVID-19) pandemic [1]. Over the last months, a plethora of novel research articles has been published, dealing with multiple aspects and manifestations of the disease. Increasing evidence points to a central role of endothelial cells (ECs) in SARS-CoV-2 infection [–5]. Early studies have already indicated increased expression of vascular and inflammatory factors (such as VCAM-1, IL-8 or MCP-1) in COVID-19 lung tissue [2]. Such markers of endothelial dysfunction and altered endothelial cell integrity are important predictors of a poor outcome in SARS-CoV-2 infections [6], and they are associated with pulmonary edema, intravascular thrombosis and acute respiratory distress syndrome (ARDS)