Cytokines are a broad category of small proteins, important in cell signaling. They are produced by a broad range of cells, including immune cells and are especially important in triggering and controlling the immune system’s response to threats. Cytokines modulate the balance between humoral immunity, the aspect of immunity mediated by macromolecules found in extracellular fluids such as secreted antibodies, complement proteins, and certain antimicrobial peptides, and cell-based immune responses. They regulate the maturation, growth, and responsiveness of particular cell populations. They are normal compounds produced in response to any kind of inflammation or infection. Once the danger is contained, their production and action decreases. With certain types of infection or insults, if too many cytokines are released and there is too much of an inflammatory response, our own tissues become damaged. This can occur because of an inappropriately robust response or in response to a very large attack.
Any organ or organ system can become overwhelmed by too much inflammation. The Covid-19 virus binds to a receptor, known as the ACE-2 receptor, which is located on the cells of the lining of the lungs called pneumocytes. The inflammatory response overwhelms these delicate pulmonocytes which are responsible for protection of the lung tissue but more importantly, gas exchange and thus oxygenation of all of our tissues.
The inflammation causes cells to become damaged leading to the release of fluids which in turn decrease oxygenation leading to difficulty breathing. This condition in general is called ARDS or Acute Respiratory Distress Syndrome. It can happen with any infection, like bacterial pneumonia or the common flu but is particularly prominent in some people with Covid-19. This is also what happened with SARS-1 and MERS, which is still present in some parts of the world, is much more lethal but much less infectious than SARS-2CoV-19.
As oxygen delivery is impaired and as a direct result of increased inflammation, other organs like the kidneys, which also contain ACE-2 receptors and are directly targeted by Covid-19, the liver and intestines start to become damaged and fail. This ultimately leads to “multi-system organ failure” and eventually people die.
With proper support, like mechanical ventilation and dialysis, patients can be supported while their immune system and resulting inflammation is dampened down and organs can recover, but not if the healthcare system is overwhelmed and supplies and ventilators are used up.
This is exactly why we have to slow down the spread of this virus.
I’ll post something separately on the issue of “flattening the curve” which will result in a longer course of all this but will also save many more lives.
Stay safe and be well.
AC 😎✌️🌱❤🐖🏃🏻🧘🏻♂️🌎