Fig. 1

Increased platelet activation in patients with SARS-CoV-2 infection. a–f Dot plot showing the correlation between platelet count and PT (a), platelet count and PTA (b), platelet count and INR (c), platelet count and APTT (d), platelet count and d-dimer (e), as well as platelet count and FDPs (F) in COVID-19 patients (n = 241). Each circle represents a different patient. g Dynamics of platelet count in COVID-19 patients with critically severe illness after hospital admission. The platelet counts values were obtained from 22 independent patients. Different colors were used for different patients. h Increased expression of platelet integrin αIIbβ3 activation (PAC-1 binding) and P-selectin (CD62P) expression in COVID-19 patients compared with healthy 11 donors and non-COVID-19 patients. Each circle represents a different individual from healthy donors (n = 166), non-COVID-19 cases (n = 60), the mild and moderate COVID-19 cases (n = 184) or the severe and critically severe COVID-19 cases (n = 57). I, PAC-1 binding and CD62P expression are correlated with platelet count in COVID- 19 patients (n = 241). Each solid circle represents a different individual. j PAC-1binding and CD62P expression in severe and critically severe type COVID-19 patients with detectable blood virus RNA (detectable, n = 12) and with undetectable blood virus RNA (undetectable, n = 45). Statistical analyses were performed using Kruskal-Wallis test with Bonferroni correction in (h), Pearson’s correlation analysis in (i) and nonparametric Mann-Whitney U test in (j). NS no significance; **P < 0.01. PT prothrombin time, PTA prothrombin time activity, INR international normalized ratio, APTT activated partial thromboplastin time, FDPs fibrinogen degradation products, undetectable: severe and critically severe type COVID-19 patients with undetectable blood virus RNA, detectable: severe and critically severe type COVID-19 patients with detectable blood virus RNA