Objectives: Severe coronavirus disease 2019 (COVID-19) is associated with a dysregulated immune state . While research has focused on the hyperinflammation, little research has been performed on the compensatory anti-inflammatory response . The aim of this study was to evaluate the anti-inflammatory cytokine response to COVID-19, by assessing interleukin-10 (IL-10) and IL-10/lymphocyte count ratio and their association with outcomes .
Methods: Adult patients presenting to the emergency department (ED) with laboratory-confirmed COVID-19 were recruited . The primary endpoint was maximum COVID-19 severity within 30 days of index ED visit .
Results: A total of 52 COVID-19 patients were enrolled . IL-10 and IL-10/lymphocyte count were significantly higher in patients with severe disease (p <0.05), as well as in those who developed severe acute kidney injury (AKI) and new positive bacterial cultures (all p & #8804; 0.01). In multivariable analysis, a one-unit increase in IL-10 and IL-10/lymphocyte count were associated with 42% (p=0.031) and 32% (p=0.013) increased odds, respectively, of severe COVID-19 . When standardized to a one-unit standard deviations scale, an increase in the IL-10 was a stronger predictor of maximum 30-day severity and severe AKI than increases in IL-6 or IL-8 .
Conclusions: The hyperinflammatory response to COVID-19 is accompanied by a simultaneous anti-inflammatory response, which is associated with poor outcomes and may increase the risk of new positive bacterial cultures . IL-10 and IL-10/lymphocyte count at ED presentation were independent predictors of COVID-19 severity . Moreover, elevated IL-10 was more strongly associated with outcomes than pro-inflammatory IL-6 or IL-8 . The anti-inflammatory response in COVID-19 requires further investigation to enable more precise immunomodulatory therapy against SARS-CoV-2.