Figure 4.

Dexamethasone treatment diminishes circulating inflammatory proteins in hospitalized COVID-19 patients. (A) PCA plot of normalized protein expression (NPX) values of circulating plasma proteins (inflammatory Olink panel) before (Pre-Dex) and 3-4 days after starting dexamethasone treatment (Post-Dex). The ellipses indicate the 95% CIs (n=9 COVID-19 patients). (B) Volcano plot depicting the distribution of the FDR and Log₂ fold change in normalized protein expression values of inflammatory plasma proteins (inflammatory OLINK panel) in COVID-19 patients before versus after dexamethasone treatment. Significantly altered proteins (FDR < 0.05) are plotted in red (n=9, Wilcoxon signed-rank test). (C) Plasma concentrations of selected cytokines in COVID-19 patients before and after dexamethasone treatment as determined by Luminex multiplex assay (n=8-9). *: P value < 0.05, **: P value < 0.01, Wilcoxon signed-rank test. (D) Plasma concentrations of ISG15 in healthy individuals and in COVID-19 patients before and after dexamethasone treatment as determined by ELISA (n=8 healthy volunteers, n=9 patient samples before and after treatment). *: P value < 0.05, **: P value < 0.01, Mann-Whitney U test (healthy vs COVID-19 patients); Wilcoxon signed-rank test (pre-Dex vs post-Dex).