SARS-CoV-2 infection alters the platelet transcriptome. RNA-seq was performed on RNA isolated from highly purified platelets from 6 non-ICU and 4 ICU SARS-CoV-2 patients and 5 matched healthy donors (HD) as described in “Methods”. (A) Hierarchical clustering of samples according to global gene expression demonstrates non-ICU SARS-CoV-2–infected patients (red numbers) and ICU (blue numbers) cluster together whereas healthy donors (gray numbers) segregate together. (B) Heat map of significantly differentially expressed platelet transcripts from SARS-CoV-2–infected ICU and non-ICU patients and healthy control donors. Red indicates increased relative expression, and blue indicates decreased relative expression. Only coding mRNAs were examined in this analysis. (C-D) Volcano plot with significantly increased (red) and decreased (blue) transcripts from non-ICU and ICU COVID-19 patients.