Cytokines and COVID-19: friends or foes?

The cytokine storm following sepsis has been proven to be an important mechanism for triggering acute respiratory distress syndrome, which is a fatal uncontrolled systemic inflammation characterized by high concentrations of pro-inflammatory cytokines and chemokines, secreted by immune effector cells. The cytokine storm also occurs in the recently emerged novel coronavirus disease (COVID-19). Therefore, cytokines which usually help the immune system to fight infections are potentially harmful in the course of COVID-19 infections. Therefore, avoiding or mitigating the cytokine storm may be a key treatment for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).