04/04/2020 - S & T

KEY POINTS

Cytokine storm

·         Cytokine storms are a common complication not only of covid-19 and flu but of other respiratory diseases caused by coronaviruses such as SARS and MERS. They are also associated with non-infectious diseases such as multiple sclerosis and pancreatitis.

·         The release of inflammatory mediators increases the blood flow to the area, which allows larger numbers of immune system cells to be carried to the injured tissue, thereby aiding the repairing process.

·         However, if this inflammatory response is not regulated, very dangerous consequences can follow. This is when a ‘cytokine storm’ can be triggered. The damage to the surrounding cells can be catastrophic, leading to sepsis and potentially, death.

What then, is the role of cytokines in the immune system?

·         Cytokines are signalling proteins that are released by cells at local high concentrations — a cytokine storm or CSS is characterised by the overproduction of immune cells and the cytokines themselves because of a dysregulation in the process.

·         A severe immune reaction, leading to the secretion of too many cytokines in the bloodstream, can be harmful since an excess of immune cells can attack healthy tissue as well.

How does CSS impact a COVID-19 patient?

·         In the case of any flu infection, a cytokine storm is associated with a surge of activated immune cells into the lungs, which, instead of fighting off the antigen, leads to lung inflammation and fluid build-up, and respiratory distress.

·         Increased pro-inflammatory cytokine responses against human coronaviruses such as SARS-CoV-1 (which caused SARS), SARS-CoV-2 (which is responsible for the current COVID-19 pandemic), and MERS can result in acute lung injury and acute respiratory distress syndrome (ARDS).

·         If the clinical features of CSS are not recognised and adequate treatment is not promptly instituted, multiple organ failure can result. Researchers writing in The Lancet have suggested that all severe COVID-19 patients should be screened for hyper inflammation.

Cytokines are a class of immunoregulatory proteins that are secreted by the cells especially of the immune system.Cytokine Storm Syndrome is a form of Systematic Inflammatory Response Syndrome that can be triggered by a variety of factors such as infections and certain drugs.It occurs when large number of white blood cells are activated and release inflammatory cytokines which in turn activate yet more white blood cells.

Role of Cytokine storm in the human immune system : 

When a pathogen enters a body which the body does not recognize on its own results in the activation of white blood cells releasing Cytokines.If it is a normal antigen then cytokine release can be regulated,but if the pathogen entered the system is of super antigen in nature then WBC releases more number of cytokines which results in Cytokine Storm Syndrome.This process when not regulated can result in Hyper Inflammation and Multiple Organ failure.Cytokine Storm Syndrome is classified into five grades where grade 1 is a normal one and grade 5 leads to death showing that regulated release of Cytokines will help in healing.

Impact on a Covid 19 Patient :

In case of any flu infection ,a cytokine storm is associated with a surge of activated immune cells into lungs which results in the excess release of cytokines.These cytokines while fighting with the antigens,because of excess in number will attack the healthy cells too which results in lung inflammation eventually leads to the respiratory distress.

Researchers have stated that the Corona virus infected patients should be screened for hyper inflammation for complete recovery of the patient.

Cytokines are signaling  proteins that are released  by cells at local high concentrations, a cytokine strom or CSS is characterized by the overproduction of immune cells and the cytokine themselves because of  dysregulation  in the process.   

·      Some point understands by this explanation that in our immune system in our bodies protect us from bacteria, viruses and parasites by removing them from our systems. The immune system gets activated when on our body attacked by antigen(bacteria, fungi and viruses).

·      An effective immune system response involves inflammation, an important and indispensable part of the process. This is visible when, for example, you hurt your knee or anke the are of this external injury becomes red and swollen and the immune system in response deploy white blood cells to the injured area to began work on recoveries.  Without such an immune response, injuries would not heal and infections would become deadly.

·      Inflammation has an Important protective function. The release of inflammatory mediators increses the blood flow to the area, which allows larger number of immune system cell to be carried to the injured tissue, there by adding the recovery process. Many time inflammatory response is not regulate properly. Due to cytokine strome can be triggered.

Cytokine Strome impact a COVID-19 patient

·      In the case of any flu infaction, a cytokine strome is associated with a surge of activated immune cells in lungs, which instead of fighting off antigen, leads to lung inmmatio and fluied buld up and repiratory distress.

Cytokin is seen as a likely major cause of mortality in both 1918-20 spanish flue that killed more than 50 million people worldwide. And H1N1(swine flue) and H5N1 (bird flu) outbreaks in recent years.