About cytokine storm
Cytokine storm or hypercytokinemia is a condition that consists of an immune reaction involving a positive feedback loop between immune cells and cytokines. Cytokines are cell-signaling molecules in the glial nervous system cells, which play the role of messengers. It is a potentially fatal reaction, associated with high death rates during pandemics of flu. The term “storm” is used because the system overacts to an intruder, for example a virus, and all the cells responsible for the immune reaction start working in an exaggerated manner. The reaction is so strong that it can seriously harm the entire system, potentially leading to fatal outcome.
Cytokine storms are more likely to occur in young, strong individuals, who have a stronger immune system. Fortunately, it is not a common condition and it is mainly seen in intensive care unit patients with severe sepsis.
The symptoms of cytokine storm are similar to those seen when the body is dealing with an infection- high fever, redness, swelling, inflammation, nausea, vomiting, extreme fatigue and such.
Causes of cytokine storm
When a pathogen, such as a virus, enters the body, cytokines signal the immune cells, for example T-cells and macrophages, to go to the infection site and fight the pathogen. Not only that- cytokines also activate those cells to more cytokines are produced. Normally, the immune system keeps this loop at a desired level.
In cytokine storm, which occurs for reasons that are not completely clear, the reaction blasts beyond control and too many immune cells get activated. This can cause significant damage to tissues and organs.
A cytokine storm can occur in many diseases, such as chickenpox, bird flu, sepsis, systemic inflammatory response disease, graft versus host disease and others.
Cytokine storms are today linked with high number of deaths in certain pandemics, such as the 1918 flu pandemic, when an unusually large number of healthy young adults died from influenza, or with the SARS epidemic in 2003.
Treatment for cytokine storms
There are several options for treating cytokine storms. One of them is OX40 immunoglobulin. ACE inhibitors and angiotensin II receptor blockers are being investigated as a potential therapy for this serious condition.
Corticosteroids and non-steroidal anti-inflammatory drugs have both been traditionally used for cytokine storms, but in clinical trials investigating their role on cytokine storms associated with acute respiratory distress syndrome they showed little or no positive effect.
Gemfibrozil, which is an agent that suppresses the production of pro-inflammatory cytokines, is currently being tested on lab animals. Other options include free radical scavengers and TNF-alpha blockers.