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.