Cytokine Storm
Further, in order to activate macrophages, the virus releases certain inflammatory mediators that cause the production of cytokines (IL-1, IL-6, and TNF) (12) and chemokines (CCL2 and CXCL10) into the bloodstream. Thus, plasma will leak into the interstitial spaces of the alveolar cells, noticeably lowering the amounts of surfactant in AT2, and compressing alveoli cells. The implications of releasing such molecules are to promote both vasodilation and capillary permeability (13-17). Alveolar collapse and reduced gas exchange are the final results of the cascade processes. Inflammatory cytokine (cytokine storm) production is also visible simultaneously (18); inflammatory mediators increase the production and recruitment of neutrophils and macrophages, which produce and utilize IL-21, IL-22, and IL-17 (13). All of these phases result in coughing, hypoxemia, and breathing difficulties in the later stages of the illness.