Association between Serum Concentrations of IL-6 And IL-10 and COVID-19 Severity

COVID-19 is a viral respiratory infection caused by SARS-CoV-2. The immune system plays a piv¬otal role in disease resolution but can also be detrimental to the clinical outcome in case of unbalanced immune activation. In this study, we have focused on the parallel expression of IL-6, a potent pro-inflam¬matory cytokine, and IL-10, an important regulator of the immune response, in COVID-19 patients. Using bead-based multiplex immunoassay technology we compared the serum levels of IL-6 and IL-10 in 47 COVID-19 patients with mild, moderate, or severe disease. The serum concentrations of both cytokines were significantly elevated in patients with severe COVID-19, and there was a significant positive correla¬tion between IL-6 and IL-10 in the moderate and severe groups (R=0.6; p<0.001). Our observations support that IL-6 is one of the driving forces for the cytokine release syndrome in COVID-19 while the immuno¬suppressive properties of IL-10 in severe disease act as a hindrance to viral clearance.