The medical community continues to learn more about how SARS-CoV-2, the virus responsible for the COVID-19 disease, affects humans, as well as how the immune system responds to it.
One of the most alarming aspects of the disease is when healthy, young adults succumb to the virus, and how mild symptoms can suddenly escalate into severe, life-threatening problems. The virus itself may not be entirely to blame for such turn of events, but rather an overreaction by the body’s immune system.
When a foreign agent — like a virus — invades the body, immune cells immediately communicate with one another to attack the virus. The cells secrete cytokines, which are “messenger” molecules that they use to “talk” with one another to initiate an immune response.
In some instances, immune cells continue to secrete cytokines even after a sufficient immune response has been mounted. Known as a “cytokine storm,” this overproduction of messenger molecules causes an excessive and destructive inflammatory response in the body.
The first published studies about cytokine storms were in the early 2000s, when researchers reported occurrences in both infectious and noninfectious diseases. Some evidence points to genetic mutations in immune cells that could make some people more susceptible to cytokine storms.
In the case of COVID-19, cytokine storms may be the reason why patients without underlying conditions or those who seem to be recovering suddenly experience severe respiratory distress syndrome.
“The battle with COVID-19 is focused on the second phase of the illness, which is mainly due to this immunologic disruption,” says Dr. Fadi Haddad, an infectious disease specialist affiliated with Sharp Grossmont Hospital.
“The disease occurs in two phases,” he says. "First, it manifests with minor symptoms, and then it progresses to a cytokine storm. In the case of COVID-19, the lungs become seriously inflamed and scarred, which can lead to difficulty breathing. In these severe cases, patients are placed on ventilators to help them breathe.”
Calming the storm
Researchers are investigating ways to calm the overactive immune response through treatments that reduce inflammation. However, developing and using the right treatment is a complex balancing act.
“There are times when the immune response needs a boost and times where it needs to be scaled back while fighting a virus,” says Dr. Haddad. “The key is to know what appropriate anti-inflammatory treatment to give and at what point in the immune response to give it. Our body’s immune system is very important for destroying foreign invaders and healing from infections. So we don’t want to prematurely stop it from working or reduce its efficiency.”
One type of treatment being explored is hydroxychloroquine, which is an antiviral and immunosuppressant drug prescribed to treat malaria and autoimmune diseases. It is being tested in COVID-19 clinical trials for its anti-inflammatory effect. Researchers are also testing a class of drugs known as immunomudulators, which regulate and normalize the immune system to reduce inflammation and resolve symptoms.
“It is unclear whether using hydroxychloroquine initially would halt progression of COVID-19,” says Dr. Haddad. “Trials are also ongoing and being planned to test the theory the immunomodulators, such as tocilizumab (Actemra), may affect the progression of the disease.”
Along with pharmaceutical therapies, some researchers have speculated that a certain ingredient in our spice pantry might help quell a cytokine storm. Curcumin, a compound found in turmeric, has long been touted as a beneficial antioxidant and anti-inflammatory against various diseases.
A study published in 2015 documented the effects that curcumin had in reducing the amount of cytokines released during a cytokine storm. In laboratory experiments, researchers found that curcumin blocked the release of cytokines specifically responsible for inflammation.
Still, doctors advise that prevention is the best treatment. Protecting oneself against COVID-19, let alone other foreign agents, means maintaining a healthy diet and lifestyle and practicing good hygiene. This includes proper hand-washing with soap and water, avoiding close contact with others, covering a cough and disinfecting touched surfaces daily.