COVID-19

=== Host cytokine response ===
[[File:Ijms-21-05932-g004.webp|thumb|Mild versus severe [[Immune system|immune response]] during [[Viral disease|virus infection]]]]

The severity of the inflammation can be attributed to the severity of what is known as the [[cytokine storm]].<ref name="pmid32474885">{{#invoke:cite journal || vauthors = Soy M, Keser G, Atagündüz P, Tabak F, Atagündüz I, Kayhan S | title = Cytokine storm in COVID-19: pathogenesis and overview of anti-inflammatory agents used in treatment | journal = Clinical Rheumatology | volume = 39 | issue = 7 | pages = 2085–2094 | date = July 2020 | pmid = 32474885 | pmc = 7260446 | doi = 10.1007/s10067-020-05190-5 }}</ref> Levels of [[Interleukin 1 beta|interleukin{{spaces}}1B]], [[Interferon gamma|interferon-gamma]], interferon-inducible protein 10, and monocyte chemoattractant protein{{spaces}}1 were all associated with COVID‑19 disease severity. Treatment has been proposed to combat the cytokine storm as it remains to be one of the leading causes of [[morbidity]] and mortality in COVID‑19 disease.<ref>{{#invoke:cite journal || vauthors = Quirch M, Lee J, Rehman S | title = Hazards of the Cytokine Storm and Cytokine-Targeted Therapy in Patients With COVID-19: Review | journal = Journal of Medical Internet Research | volume = 22 | issue = 8 | pages = e20193 | date = August 2020 | pmid = 32707537 | pmc = 7428145 | doi = 10.2196/20193 |doi-access=free}}</ref>

A cytokine storm is due to an acute hyperinflammatory response that is responsible for clinical illness in an array of diseases but in COVID‑19, it is related to worse prognosis and increased fatality. The storm causes acute respiratory distress syndrome, blood clotting events such as strokes, myocardial infarction, [[encephalitis]], [[acute kidney injury]], and [[vasculitis]]. The production of [[Interleukin 1|IL-1]], [[Interleukin 2|IL-2]], [[Interleukin 6|IL-6]], [[Tumor necrosis factor|TNF-alpha]], and [[Interferon gamma|interferon-gamma]], all crucial components of normal immune responses, inadvertently become the causes of a cytokine storm. The cells of the [[central nervous system]], the [[microglia]], [[neuron]]s, and [[astrocyte]]s, are also involved in the release of [[pro-inflammatory cytokine]]s affecting the nervous system, and effects of cytokine storms toward the [[Central nervous system|CNS]] are not uncommon.<ref>{{#invoke:cite journal || vauthors = Bhaskar S, Sinha A, Banach M, Mittoo S, Weissert R, Kass JS, Rajagopal S, Pai AR, Kutty S  | title = Cytokine Storm in COVID-19-Immunopathological Mechanisms, Clinical Considerations, and Therapeutic Approaches: The REPROGRAM Consortium Position Paper | journal = Frontiers in Immunology | volume = 11 | pages = 1648 | year = 2020 | pmid = 32754159 | pmc = 7365905 | doi = 10.3389/fimmu.2020.01648 | doi-access = free | title-link = doi }}</ref>