Localization of Spike protein in platelets from patients with severe COVID-19. The intraplatelet localization of Spike protein was investigated by immunofluorescence and super-resolution confocal microscopy with the Airyscan module using a specific anti-Spike antibody. Its colocalization with LC3B, a marker of autophagosomes (A), EEA1, a marker of early endosomes (B), and Rab7, a marker of late endosomes (C), was analyzed. Representative images from 5 different patients with severe COVID-19 are shown (bar represents 1 µm). Quantification was performed from the analysis of 30 to 40 platelets from each of the 5 patients with severe COVID-19 analyzed. Pearson’s correlation coefficient and Manders’ coefficient calculations are shown (D). *P < .05; **P < .01; ****P < .0001 according to the nonparametric Mann-Whitney test.