In recent news, “cytokine storms” have been discussed fervently in the news. Whether the cytokine storm is linked to Covid, cancer treatment, or the body’s response to severe inflammation- these “storms” can have deadly consequences for many.
Using the term “cytokine storm” draws imagery of an immune system that has gone haywire, and the inflammation response has begun to spiral out of control. These storms are associated with numerous infectious and noninfectious diseases, autoimmune disorders and diseases, organ dysfunction, and many other medical issues. There have also been linked cases to viral diseases, like influenza.
What are Cytokines?
Cytokines are a mixed group of proteins that are secreted by cells for the purpose of intercellular signaling and internal body communication. Specific cytokines have paracrine, autocrine, or endocrine activities, and with receptor binding, can trigger a variety of responses- depending on the cytokine and the cell it is targeting. Cytokines help to control cell proliferation and differentiation, along with the regulation of angiogenesis, immune and inflammatory responses.
Cytokines can have multiple functions and other unrelated functions that depend solely on their targeted cell or the presence or absence of other cytokines. While some have limited sequence and interact with distinct receptors and transduce signals through common pathways. This happens because of the diversity of the cytokine structure and function, along with the classification and naming of cytokines- making fully understanding these storms exceedingly difficult.
The extremely complex network of what occurs during a cytokine storm is considered a series of overlapping networks, each with different degrees of redundancy with numerous alternate pathways. The combinations of these networks have important implications when identifying the key steps in the cytokine response to infection and in determining and targeting specific cytokines for therapeutic interventions.
What is a cytokine storm?
A severe immune reaction in which the body releases too many cytokines into the blood too quickly. Cytokines play an important role in normal immune responses but having a large amount of them released in the body all at once can be harmful. A cytokine storm can occur because of an infection, autoimmune condition, or other disease. It may also occur after treatment with some types of immunotherapies. Signs and symptoms include high fever, inflammation, severe fatigue and nausea. Sometimes, a cytokine storm may be severe or life threatening and lead to multiple organ failure.
Inflammation Responses with a Cytokine Storm
The inflammation that occurs with a cytokine storm begins at a local site or area in the body and spreads throughout the body due to our systemic circulation system. Redness, tumors (which can include swelling and/or edema, skin that is hot to the touch (or Calor), pain around the body (dolor), and loss of functions are the common hallmark signs of acute inflammation. When localized on the skin or other tissues, these responses increase blood flow, enable vascular leukocytes along with plasma proteins to reach the site of the injury, which increases the temperature, can generate pain, which signal your brain to have a local response.
These local responses most often occur at the expense of local organ function, especially when tissue swelling has triggered the rise in extravascular pressures and a reduction in tissue perfusion. The body then signals compensatory repair processes that are initiated after the inflammation began. When severe inflammation or the primary triggering agent damages these body tissues and structures, healing will occur with fibrosis, which results in persistent and permanent organ dysfunction.
Cytokine Storms & Covid
In today’s Covid centered world, the best example of a cytokine storm would be what happens to the lungs with this SARS-Covid infection. The lungs become increasingly inflamed due to the virus taking over, which hinders normal body functions, and the inflammation then spills into other organ functions, sometimes causing a massive organ system to shut down. In more controlled cases, the lungs may “heal,” but with heavy fibrosis from damage which makes the patient require oxygen for life and be forced to live a different life where activity is severely limited.
Citations:
National Institutes of Health and Human Services
World Health Organization