The COVID-19 cytokine storm and its immunomodulatory treatment

Dysregulation of the immune system mounting to a “cytokine storm (CS)” was early recognized as a turning detrimental point in the course of the coronavirus disease (COVID-19). Extensive research and clinical trials evaluated key biomarkers and potential medications to prevent or treat CS. The unprecedented pandemic has mandated the immediate search for potential drug candidates. In response to the quickly evolving situation, it was early recognized that repurposing of available immunomodulators could save lives in a timely manner by skipping the lengthy phases of preclinical and initial safety studies. Accordingly, a number of immunomodulators were repurposed based on previously used medications for CS associated with other conditions with immune dysregulation. In this chapter, we discuss the pathogenesis of COVID-19 cytokine storm, highlighting the therapeutic targets with immunomodulatory effects. Then, we reflect on the immunomodulators recommended in the guidelines of the National Institute of Health and their supportive clinical trials.