Abstract

Inflammatory storm, or cytokine storm, is an overactivation of the immune system caused by infection, drugs, or certain diseases that can rapidly lead to single or multiple organ failure, eventually threatening life. Cytokine storms have been an important cause of death in COVID-19, SARS, MERS and influenza. Cytokines mainly include interferon (IFN), interleukin (IL), chemokines, colony stimulating factors (CSFs), tumor necrosis factor (TNF) and so on. These cytokines are secreted by certain immune cells, and some of their functions are to promote inflammation, some are to inhibit inflammation, to maintain a state of equilibrium in the normal human body. When the immune system is over-activated due to infection, drugs, autoimmune diseases and other factors, it may secrete a large number of pro-inflammatory factors, leading to a positive feedback loop, which breaks through a certain threshold and becomes uncontrollable and over-amplified, finally forming cytokine storm.