It is, and some researchers have been apprehensive about the use of corticosteroids because they might inhibit the immune response.
However, sometimes the body’s inflammatory response to disease and infection is exaggerated and becomes counterproductive.
For example, people who become very sick from COVID-19 can develop severe viral pneumonia, which is inflammation of the lungs. The parts of the lungs that are vulnerable to inflammation are the alveoli, tiny air sacs where the exchange of oxygen and carbon dioxide takes place.
This inflammation should be helpful as the fluid entering the alveoli is full of white blood cells and disease-fighting components, but too much fluid build-up makes breathing difficult. Some people with COVID-19 need oxygen therapy, or a mechanical ventilator, to help them breathe because of the amount of fluid in their lungs.
There is a delicate balance between reducing inflammation and shutting off the immune system altogether, which is why the use of corticosteroids has been approached carefully.
Doctors and researchers are also trying to prevent another type of inflammation. Coronaviruses (including those that cause COVID-19, SARS and MERS) are associated with an immune response called a ‘cytokine storm’. A cytokine is a small protein produced by the body that acts like a messenger between the immune system and immune cells.
When SARS-CoV-2 (the virus that causes COVID-19) enters the body, the immune system reacts by producing cells that will attack the region infected with the virus. These cells are ‘directed by’ cytokines, which trigger inflammation when they are released.
Certain people infected with SARS-CoV-2 release more cytokines than necessary, attracting an oversupply of white blood cells to the area. These white blood cells, in turn, produce more cytokines resulting in a dangerous cycle of inflammation; a cytokine storm. When unchecked, this can result in organ damage, organ failure and possibly death. It is also not yet known why some people have this exaggerated immune response to COVID-19, but research is underway.
A corticosteroid like dexamethasone, that reduces inflammation, could be promising in reducing the effect of this type of event.