Fig. 2. Cytokine correlation to age, HT, and DS in the COVID-19 patient cohort.

Correlation matrix between cytokines and age, DS, and HT (A). The upward slope of the ellipses shows positive correlations in blue whereas downward ones show negative correlations in red. Color intensities and sizes of ellipses are proportional to the absolute value of the corresponding Pearson correlation coefficients (legend at the bottom side). The analytes are clustered according to the similarity of their correlation coefficients (horizontal black lines) using the “hclust” function of the R package “stats” according to the “ward.D2” method applied to ‘manhattan’ distances. Figure generated with the R package corrplot³². Individual cytokine details of Pearson’s correlation (95% confidence interval) of the indicated analytes with age (B, gray and horizontal lines), DS (C, orange and vertical lines 0 = mild, 1 = moderate, 2 = severe, 3 = critical) and HT (D, green and diagonal pattern) are indicated within each graph together with the two-tailed p-value analysis (boxed). *p < 0.05, **p < 0.01, ****p < 0.0001.