Figure 1.

Experimental approach, clinical characteristics, and identification of the main immune cell types in COVID-19 patients based on mass cytometry

(A) Schematic of the study design of the cohort.

(B) Boxplots showing the age distribution, selected clinical parameters at admission, and the NK cell counts in the patient cohort split by disease severity (n = 22 healthy controls, 28 mild COVID-19 patients, and 38 severe COVID-19 patients).

(C) Correlation map of the indicated parameters and clinical features grouped by a hierarchical clustering on the COVID-19 patients. The circle color reflects the magnitude of the Pearson’s correlation coefficient (red indicates positive correlation, blue indicates negative correlation). Asterisks represent the statistically significant correlations (∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001).

(D) t-SNE plot of a random subset of 1,000 immune cells of the mass cytometry analysis from each sample (n = 78 individuals) colored by main cell types as identified based on a random forest cell classification.

(E) Heatmap of the normalized marker expression in the main cell types. Relative abundances of each cell type are plotted to the right of the heatmap.

(F) Boxplots comparing the frequencies of the indicated cell types in healthy controls and patients with mild and severe disease.

Statistical analyses were performed with a Mann-Whitney-Wilcoxon test corrected for multiple testing using the Holm method, and p values are shown if the results were significant (p < 0.05).