Researchers may have discovered a new biomarker of acute COVID-19

Researchers at the Karolinska Institute in Sweden found increased levels of the cytokine IL-26 in the blood of patients with acute COVID-19 infection
.
In addition, high IL-26 levels were associated with an exaggerated inflammatory response, suggesting severe cases of
the disease.
The findings, published in the journal Frontiers in Immunology, suggest that IL-26 is a potential biomarker for severe COVID-19
.

SARS-CoV-2 vaccines have been shown to be effective
in reducing the number of severe COVID-19 cases.
However, the emergence of new virus variants, limited distribution of vaccines, and declining immunity are issues
that drive scientists to find more effective treatments.

"To find better treatments, we need to learn more about the underlying immune mechanisms
.
In addition, there is a need to improve diagnostic methods for COVID-19 patients," said
Eduardo Cardenas, a postdoctoral researcher at the Institute of Environmental Medicine at the Karolinska Institutet and lead author of the new pilot study.

For the first time, researchers have attempted to determine whether immune signals delivered through the cytokine interleukin-26 (IL-26) are associated
with severe COVID-19.

"We already know that IL-26 is involved in mobilizing immune cells to fight bacterial infections in the lungs and also against chronic respiratory diseases in humans," said
Anders Lindén, the study's last author and a consultant and professor at the Institute of Environmental Medicine at Karolinska.
In addition, IL-26 has antiviral and antibacterial effects
.
”

To study how this molecule is involved in COVID-19, the scientists recruited 49 patients hospitalized with SARS-CoV-2 infection, 44 of whom were severely symptomatic and required oxygen therapy
.
The patients were recruited
at a hospital in Stockholm between June 2020 and January 2021.
Twenty-seven healthy individuals were also recruited as a control group
during the same period.
The researchers then measured levels of
the IL-26 protein and other inflammatory compounds in the blood.

Dr Cardenas said: "For the first time, we can show that the level of cytokine IL-26 in the blood of COVID-19 patients is much higher than in healthy controls
.

The researchers also found that this increase was associated with so-called cytokine storms, an excessive and dangerous inflammatory response that marks severe cases
of COVID-19.

Professor Lindén said: "Our findings provide us with a potential biomarker for severe COVID-19, but given the antiviral effects of IL-26, we may also have identified a new therapeutic target
.
"

According to Dr.
Cardenas, the results are promising, but this is preliminary and further research
in a larger patient cohort is needed.

"Such studies are ongoing, and it could provide more information about the clinical value of measuring IL-26 in COVID-19 patients, such as whether its levels reflect the severity of
the disease.
"

Increased IL26 associates with markers of hyperinflammation and tissue damage in patients with acute COVID19