Cytokine Storm and COVID-19

Garnering mass attention due to the COVID-19 pandemic caused by the SARS-CoV-2 virus, the “cytokine storm” has been observed for decades. Cytokine storm refers to the overproduction of cytokines by the body in response to an infection. The production of cytokines is a normal part of the body’s immune response, but in some cases, the body tries to clear the infection so much so that the collateral damage done to the body is life-threatening.

While initial symptoms may vary, nearly all patients have a fever, and many experience headache, fatigue, diarrhea, rash, respiratory symptoms such as cough, and even neuropsychiatric symptoms when experiencing this phenomenon. This may be due in part to cytokine-induced organ damage.

The exact mechanisms of organ injury caused by the SARS-CoV-2 virus are still under investigation, but there have been reports of elevated cytokine levels as well as inhibition of viral replication with the use of immunosuppressants. For example, Interleukin-6 or IL-6 blood levels increase, which has been correlated with disease mortality. Other chemokines and cytokines that increase during COVID-19 include CXCL10, IL-2, IL-7, IL-10, G-CSF, MCP1, MIP1α, and TNF.

IL-6 or interleukin-6 has a variety of functions, including immunity, metabolism, and tissue regeneration. CXCL10 is a pro-inflammatory cytokine involved in processes such as chemotaxis, differentiation, peripheral immune cell activation, cell growth regulation, and apoptosis. IL-2 or interleukin-2 is required for T-cell proliferation, and can stimulate B-cells, lymphokine-activated killer cells, monocytes, natural killer cells, and glioma cells. IL-7 or interleukin-7 is a hematopoietic growth factor stimulating lymphoid progenitors during B-cell maturation. IL-10 or interleukin-10 is an anti-inflammatory protein regulating the inflammation response. G-CSF or granulocyte colony-stimulating factor is a hematopoietic growth factor controlling the production, differentiation, and function of granulocytes. MCP1 or CCL2 induces a chemotactic response in basophils and monocytes to sites of inflammation. MIP1α or CCL3 induces a chemotactic response in polymorphonuclear leukocytes to sites of inflammation and induces fever. TNF or tumor necrosis factor mediates inflammation and induces fever.

The cytokine storm is still a relatively new discovery, scientifically speaking, and is actively being studied. ProSci enhances this research through supplying high performance cytokine and chemokine antibodies and recombinant proteins.

References:

N Engl J Med. 2020 Dec 3;383(23):2255-2273. doi: 10.1056/NEJMra2026131.

Inflamm Regen. 2020 Oct 1;40:37. doi: 10.1186/s41232-020-00146-3.