Background: In SARS-CoV-2 infection there is an urgent need to identify patients that will progress to severe COVID-19 and may benefit from targeted treatment.
Objectives: Analyze plasma cytokines in COVID-19 patients and investigate their association with respiratory failure (RF) and treatment in Intensive Care Unit (ICU).
Method: Hospitalized patients (n=34) with confirmed COVID-19 were recruited into a prospective cohort study. Clinical data and blood samples were collected at inclusion and after 2-5 and 7-10 days. RF was defined as PaO2/FiO2 ratio (P/F) <40kPa. Plasma cytokines were analyzed by a Human Cytokine 27-plex assay.
Measurements and Results: COVID-19 patients with RF and/or treated in ICU showed overall increased systemic cytokine levels. Plasma IL-6, IL-8, G-CSF, MCP-1, MIP-1α levels were negatively correlated with P/F, whereas combinations of IL-6, IP-10, IL-1ra and MCP-1 showed the best association with RF in ROC analysis (AUC 0.79-0.80, p<0.05). During hospitalization the decline was most significant for IP-10 (P<0.001).
Conclusion: Elevated levels of pro-inflammatory cytokines were present in patients with severe COVID-19. IL-6 and MCP-1 were inversely correlated with P/F with the largest AUC in ROC analyses and should be further explored as biomarkers to identify patients at risk for severe RF and as targets for improved treatment strategies.