Platelet-monocyte complexes express TF in severe COVID-19 patients. (A-B) The percentage of TF surface expression on monocytes (A) or platelets (B) from SARS-CoV2⁻ control volunteers, SARS-Cov2⁺ asymptomatic subjects, or symptomatic patients presenting mild to severe COVID-19 syndrome. (C) The percentage of TF surface expression on monocytes that were complexed with platelets (CD14⁺CD41⁺) or circulating freely (CD14⁺CD41⁻) in severe COVID-19 patients. The horizontal lines in the box plots represent the median, the box edges represent the interquartile ranges, and the whiskers indicate the minimal and maximal value in each group. *P < .05 between selected groups.