Interleukin-6, a major player of cytokine storm in COVID-19 and its alleviation by therapeutic antibodies

Interleukin-6 (IL-6) is an important cytokine that plays a vital role in immune response and inflamma-tion. Here, the signalling functions of IL-6 through its receptors, physiological and pathological roles, espe-cially its contribution to various autoimmune diseases, cancers and severe COVID-19/SARS-CoV2 infections are described. It is reported that in severe COVID-19 infection and auto-immune diseases, the patients expe-rience cytokine storms due to hyper-activation of the IL-6 receptor pathway leading to detrimental effects. Blocking IL-6 receptor action by therapeutic antibodies has been considered an attractive strategy of treat-ment. The latest findings on the application of anti-IL-6 therapeutic antibodies in COVID-19 patients are also discussed.