For this purpose, (i) we determined the baseline level of serum vascular adhesion molecule-1 (VCAM-1), E-selectin, ACE2 and Lp-PLA2 in parallel to platelet-specific soluble P-selectin and CD40L concentrations in severe COVID-19; (ii) the levels of these biomarkers were correlated with each other and the routinely measured prognostic markers, such as ferritin and interleukin-6 (IL-6), as well as the disease severity evaluated according to the Horowitz index; and (iii) the predictive value of these vascular dysfunction-related markers was evaluated for mortality in severe SARS-CoV-2 infection. Here, IL6 is linked to COVID-19.