Inflammation and Cytokine Storm Assays in COVID-19 patients
Measure biomarkers of inflammation with ProcartaPlex multiplex immunoassay panels. Simultaneously quantitate up to 65 soluble immune biomarkers from a single sample. Use preconfigured chemokine and cytokine panels or select from single targets to create your own custom panel to detect and quantitate the inflammatory response.
Inflammation & hyper-inflammation
As part of the immune response, inflammation plays an important role in defending the body against pathogens, such as viruses, bacteria, fungi, and other parasites. However, the inappropriate activation of inflammatory processes is an underlying contributor to many common pathological conditions. For example, autoimmune conditions arise when our immune system mistakes our cells or tissues for pathogens and attacks them. In addition, studies show that tumor proliferation and metastasis may occur when inflammatory cytokines create a microenvironment conducive to cancer progression.
Acute versus chronic inflammation
Acute inflammation is a short-lived response that is characterized by extravasation of leukocytes, erythrocytes, and plasma components into the injured tissue. If left unchecked, the acute inflammatory process can lead to chronic inflammation. Unlike acute inflammation, chronic inflammation is characterized primarily by tissue infiltration by lymphocytes and macrophages. Chronic inflammation is closely associated with allergy, atherosclerosis, cancer, arthritis, and Alzheimer’s disease, as well as autoimmune diseases. The process of acute inflammation is well defined, but the causes of chronic inflammation and its associated molecular and cellular pathways are still not well understood.
The critical balance between pro- and anti-inflammatory mediators
The overall effect of an inflammatory response is dictated by the balance between pro- and anti-inflammatory mediators. Pro-inflammatory cytokines such as IL-1 beta, IL-6, and TNF alpha are responsible for early responses and amplify inflammatory reactions, whereas anti-inflammatory cytokines, which include IL-4, IL-10, and IL-13, have the opposite effect in that they limit the inflammatory reactions. The increasing complexity of pro- and anti-inflammatory cytokine and chemokine networks has made it crucial to examine them in relevant functional groups rather than individually.
Hyper-inflammation and cytokine storm
A typical immune response involves production of cytokines that orchestrate the differentiation of lymphocytes based on the type of pathogen being cleared. Ultimately the immune system self-regulates and shuts down once the infection is resolved. In some cases, however, the immune response does not shut down, and there is an overproduction of inflammatory cytokines that causes systemic damage to host cells.
The so-called cytokine storm or cytokine release syndrome (CRS) is characterized by an aggressive pro-inflammatory response in combination with an insufficient an anti-inflammatory response, which results in the loss of homeostasis of the immune response. The key factors identified in the pathology of a cytokine storm are TNF alpha, Interferons, IL-1 beta, MCP-1 (CCL2), and most importantly IL-6.
Activation of mainly T cells or lysis of immune cells induces a release of IFN gamma or TNF alpha. This leads to the activation of macrophages, dendritic cells, other immune cells, and endothelial cells. After activation, these cells further release proinflammatory cytokines. Large amounts of Interleukin 6 (IL-6) are produced by macrophages and endothelial cells, activating T cells and other immune cells and creating a positive feedback-loop that results in a cytokine storm, inducing the release of many more cytokines and chemokines but also upregulating acute phase proteins. The resulting cytokine storm syndromes are heterogeneous but have the described immune dysregulation in common, leading to hyperinflammation, fever, cytopenia, splenomegaly, hepatitis, coagulopathy, and may result in fatal multisystem organ dysfunction.
Infectious diseases associated with a hyperreactive immune system may be caused by different pathogens, such as bacteria (e.g. toxic shock syndrome (TSS)) and viruses (e.g. Influenza, Epstein-Barr Virus, SARS and SARS COV-2)). In addition, the cytokine storm has been described in therapeutic environments such as immunotherapy and CAR-T cell therapy in cancer. Treatment of patients with therapeutic monoclonal antibodies may stimulate a massive cytokine release syndrome leading to life threatening side effects of immunotherapy. Recently described by Cheng et al., exposure to organic pollutants could elicit a hyper reactive immune response. Exposure to polycyclic aromatic hydrocarbons was linked to increased serum levels of cytokines associated with a cytokine storm.
Protein biomarkers for Cytokine Storm or Cytokine Release Syndrome in the ProcartaPlex Multiplex Cytokine Assay
|Target||Type||Role associated with COVID-19|
|G-CSF (CSF-3)||Cytokine (Colony-Stimulating Factors)||CRS, cytokine profile associated with sHLH and severe COVID-19.|
|GM-CSF||Cytokine (Colony-Stimulating Factors)||Inflammatory cytokine released during CRS, stimulates IL-6.|
|IFN alpha||Cytokine (Interferon), pro-inflammatory||Key player in CRS, innate immunity to viruses.|
|IFN gamma||Cytokine (Interferon), pro-inflammatory||Key mediator of CRS, described in SARS patients, potential marker to predict COVID-19 outcome, potential therapeutic target.|
|IL-1 beta||Cytokine, pro-inflammatory||Plays a central role in CRS, is considered a potential target for COVID-19|
|IL-2||Cytokine, pro-inflammatory||Released during CRS, stimulates IL-6.|
|IL-4||Cytokine, anti-inflammatory||Important for homeostasis in the immune response, stimulates IL-6.|
|IL-5||Cytokine||Main biomarker for sepsis, involved in CRS and has a role in influenza infection induced CRS.|
|IL-6||Cytokine, pro-inflammatory||Key mediator of CRS, potential therapeutic target, blocking IL-6 potentially beneficial for patients with severe inflammation in the lungs due to CRS, increased plasma levels in ICU vs. non-ICU patients for COVID19.|
|IL-8 (CXCL8)||Chemokine (CXC type), pro-inflammatory||CRS in SARS patients, chemoattractant for various immune cells.|
|IL-10||Cytokine, anti-inflammatory||Important for homeostasis in the immune response, stimulates IL-6.|
|IL-12p70||Cytokine, pro-inflammatory||Plays a role in CRS.|
|IL-13||Cytokine, immunoregulatory||Secreted by NK cells, plays a role in MAS.|
|IL-17A (CTLA-8)||Cytokine, pro-inflammatory||Plays a role in CRS provoked by TSS, increased level in PAH exposure associated cytokine storm.|
|IL-18||Cytokine, pro-inflammatory||Involved in CRS in SARS patients.|
|IP-10 (CXCL10)||Chemokine (CXC type)||CRS associated with sHLH, and severity of COVID-19, increased plasma levels in ICU vs. non-ICU patients.|
|MCP-1 (CCL2)||Chemokine (CC type)||Central role in CRS, associated with sHLH; CRS in SARS patients and severity of COVID-19, increased plasma levels in ICU vs. non-ICU patients|
|MIP-1 alpha (CCL3)||Chemokine (CC type)||Cytokine profile associated with sHLH and severity of COVID-19; increased plasma levels in ICU vs. non-ICU patients, potential marker to predict COVID-19 disease severity/outcome.|
|MIP-1 beta (CCL4)||Chemokine (CC type)||Biomarker for sepsis and CRS in general.|
|TNF alpha||Tumor necrosis factor||Central role in CRS, blocking TNF alpha potentially beneficial for patients with severe inflammation in the lung due to CRS, increased plasma levels in ICU vs. non-ICU patients.|
|TNF beta||Tumor necrosis factor||CRS in SARS patients, plays a role in the TNF-dominated response to superantigens leading to STSS.|