Dysfunction of the immune system can lead to serious consequences of COVID-19 (pictorial)
New York:
Scientists have found how immune system failures in some patients infected with the novel coronavirus can lead to serious consequences from COVID-19, a breakthrough that may help identify people at high risk of dying from the disease and suggest drugs for treat them.
Researchers at Yale University in the United States examined 113 patients admitted to Yale Hospital New Haven and analyzed the different immune system responses they exhibited during their stay in hospital, from admission on discharge or death.
The study, published in the journal Nature, found that all patients shared a common COVID-19 “signature” in immune system activity at the onset of illness.
However, those who only exhibited moderate symptoms had decreased immune system responses and levels of viral particles in their bodies over time, the researchers said.
“This study shows how people’s immune systems respond to SARS-CoV-2. It shows that the wrong types of immune responses are initiated in severe cases and how some of them are associated with mortality,” noted the lead study author Akiko Iwasaki from Yale University in a tweet.
According to the scientists, patients who developed severe cases of the disease showed no decrease in the levels of viral particles in their body, nor any reaction from the immune system.
They said many immune signals in these patients, including molecules called cytokines, were accelerated.
But even at the start of treatment, researchers found factors that predicted which patients were most at risk of developing severe forms of the disease.
“We were able to pull off disease risk signatures,” Akiko Iwasaki said.
While previous studies have identified that the immune system has triggered a massive and damaging “cytokine storm” in severe cases of COVID-19, scientists said the specific elements of this response were unknown.
The current study found that a risk factor was the presence of an immune system molecule called interferon alpha – a cytokine mobilized to fight viral pathogens such as the influenza virus.
However, the researchers said that patients with COVID-19 with high levels of alpha interferon performed worse than those with low levels.
“This virus just doesn’t seem to care about alpha interferon. The cytokine seems to hurt, not to help,” Akiko Iwasaki said.
Another early prognosis for poor outcome, according to the study, is the activation of a protein complex that detects pathogens and triggers an inflammatory response to an infection called an inflammasome.
The researchers said activation of the inflammasome was linked to poor outcomes and the death of several patients.
They found that people who respond better to infection tend to express high levels of growth factors – a type of immune system molecules that repairs tissue damage in the linings of blood vessels and lungs.
Taken together, the researchers believe the data can help predict patients at high risk for poor disease outcomes.
They added that drugs that specifically target the causes of inflammation identified in the study could help treat patients at risk of developing severe cases of COVID-19.
(This story was not edited by GalacticGaming staff and is auto-generated from a syndicated feed.)
