ICU COVID-19 IgG-induced formation of procoagulant PLTs is FcγRIIA dependent. (A) ICU COVID-19 patient serum-induced changes of Δψ as well as ICU COVID-19 IgG-induced formation (B) of procoagulant PLTs were analyzed in the presence or absence of moAb IV.3 via FC. Data are presented as mean percentage of (A) Δψ depolarized PLTs and (B) CD62p/PS-positive PLTs ± SEM. The number of patients and healthy donors tested is reported in each graph. See Figure 1 for P values and abbreviation definitions.