JUL 29, 2020 2:50 PM PDT

Immune Variation Explains Different COVID-19 Outcomes

WRITTEN BY: Kara Marker

Immune systems respond differently to coronavirus infection. People experience the disease causes by coronavirus, COVID-19, in different intensities, from moderate to severe. The two are connected, and the intricate details of one may help scientists predict the other.

From Yale University, scientists have uncovered specific indicators of how a positive COVID-19 case is likely to turn out: moderate or severe. One of the many mysteries of the COVID-19 pandemic has been how the virus affects people on such a wide spectrum of severity. With these indicators, researchers may provide a way to harness predictive power, thus guiding therapeutic regimens for high-risk patients.

The Yale study consisted of 113 patients with confirmed COVID-19, monitoring and measuring each participant’s unique and changing immune response to the infection for the entire duration of their stay in the hospital. When patients are in the beginning stages of COVID-19, many share the same immune “signature,” even though these patients may have very different outcomes as the disease runs its course.

In general, a moderate case of COVID-19 is characterized by an immune response and viral load that ultimately decreases over time as the infection is cleared by the body. But in severe disease, immune activity and viral load do not decrease. In some cases, it’s quite the opposite.

In the most severe cases of COVID-19, researchers have seen an excessive immune response to infection that leads to what is essentially “friendly fire.” This phenomenon of the body’s own inflammatory immune response wreaking havoc during infection has been called the “cytokine storm.” Cytokines are small cell signaling proteins with a wide array of functionalities, many with inflammatory associations.

With the onslaught of cytokine storms occurring in patients struggling with COVID-19, scientists have been asking: at what point do immune response levels blast past the threshold into dangerous, detrimental territory that has been characteristic of severe COVID-19 cases?

From their observations, Yale scientists identified severity risk indicators early on, when COVID-19 patients shared many characteristics, when a case that would ultimately end up in a long hospital stay looked just like one that would be recovered after not too long.

They found that high levels of a cytokine called alpha interferon were indicative of a risk for severe COVID-19. This cytokine is common in the immune response to viral pathogens, like the flu. Unlike other viral pathogens, coronavirus is not inhibited by alpha interferon, so the cytokine ends up doing more harm than good.

Another indicator is the activation of the inflammasome, a protein complex that mounts an inflammatory response in the presence of pathogenic infection.

There were also indicators of a COVID-19 case that was likely to be mild: high levels of growth factors, for tissue repair in the linings of blood vessels and lungs.

Sources: Yale University, Nature, International Anesthesiology Clinics

About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
APR 16, 2020
Health & Medicine
Structural Basis of Receptor Recognition by SARS-CoV-2
APR 16, 2020
Structural Basis of Receptor Recognition by SARS-CoV-2
As mortality and infection rates rise globally, it appears that SARS-CoV-2, the virus responsible for the COVID-19 pande ...
APR 22, 2020
Immunology
Scientists Engineer Custom Antiviral Receptors to Fight COVID-19
APR 22, 2020
Scientists Engineer Custom Antiviral Receptors to Fight COVID-19
The best offense may be a good defense in the fight against COVID-19. Researchers from the Duke-NUS Medical School are e ...
MAY 19, 2020
Drug Discovery & Development
COVID-19 Vaccine On Track for Late 2020
MAY 19, 2020
COVID-19 Vaccine On Track for Late 2020
Moderna, a biotechnology company based in Massachusetts, has released information on its vaccine against COVID-19 from i ...
MAY 19, 2020
Drug Discovery & Development
Can Chinese Drug Cure COVID-19 Without Vaccine?
MAY 19, 2020
Can Chinese Drug Cure COVID-19 Without Vaccine?
Researchers at China’s Peking University have announced that they are developing a treatment capable of blocking C ...
JUN 20, 2020
Cell & Molecular Biology
Antibodies Isolated From COVID-19 Patients Show Therapeutic Potential
JUN 20, 2020
Antibodies Isolated From COVID-19 Patients Show Therapeutic Potential
Communities worldwide are emerging from lockdowns due to the SARS-CoV-2 pandemic virus, and cases are rising.
AUG 11, 2020
Drug Discovery & Development
Scientists Discover Key Gene Behind Antibiotic Resistance
AUG 11, 2020
Scientists Discover Key Gene Behind Antibiotic Resistance
Scientists from Oxford University have shown that a single gene can make some strains of Staphylococcus aureus (the bact ...
Loading Comments...