Identification of key cytokines that predict intensive care unit admission and mortality in patients with severe COVID-19

The complete understanding of the pathogenesis of severe COVID-19 is still in progress, and many studies have pointed to the hyperstimulation of host immune response through uncontrolled expression of inflammatory soluble factors that become detrimental to the host as a major culprit. The cytokine release syndrome (CRS), which has been observed in patients with severe COVID-19, results from the production of excessive and disproportionate amounts of proinflammatory and anti-inflammatory cytokines and associated mediators by immune cells. This condition of hyperinflammation leads to tissue injuries, extensive lung damage, hypercoagulation, and thrombosis that further worsen the disease condition and ultimately lead to mortality. Identification of key cytokines that are involved in this observed exacerbation of immune response could provide potential targets for immunological therapy. This study analyzed an array of cytokines, chemokines, and growth factors in the sera of 100 patients with COVID-19 at the time of hospitalization, admission into the intensive care unit (ICU), as well as in deceased patients employing a multiplex bead assay. The results obtained identified elevated serum levels of IL-1RA, IL-6, IL-10, IL-17, IL-27, TNF-β, CCL2, and HGF, as well as decreased levels of IL-4, CCL-11, and PIGF-1, as not only predictors of ICU admission but also as potential signals of mortality-associated severity of COVID-19. These findings would facilitate the understanding of CRS mechanisms and their profile, which are crucial to developing effective therapeutic approaches against COVID-19.