ABSTRACT
Cytokine storms can be triggered by various infectious or noninfectious diseases and cause severe damages to multiple organs. Cytokine storm plays an important role in the pathogenesis of severe cases of coronavirus disease 2019 (COVID-19). The pathogenesis of COVID-19 involves a potent inflammatory response involving a complex group of mediators, including interleukin (IL)-6 and IL-10. In this study, the serum levels of IL-6 and IL-10 cytokines were evaluated in 79 COVID-19 infected patients from the National Hepatology and Tropical Medicine Research Institute, Cairo, Egypt. And 20 healthy individuals served as a control group. The patients were divided into moderate, severe, and critically ill. In this study, IL-6 and IL-10 levels were significantly elevated in COVID-19 patients compared with healthy controls. IL-6 levels were significantly higher in patients compared with controls (p = 0.001), although it was not varied within different severity groups except for moderate-critical ill cases (p < 0.033). IL-10 only showed a significant difference between critically ill and control cases (p < 0.002). Receiver operating characteristic curve analyses showed that IL-6 levels >120 pg/mL can predict moderate and critically ill patients with a sensitivity of 90.48% and a specificity of 62.50%, Area Under the Curve <0.0001. In conclusion, the serum levels of IL-6 cytokine are important noninvasive biomarkers to differentiate between moderate and critically ill COVID-19 infected patients.