Researchers may have found a new biomarker for COVID-19 after discovering that acute patients have increased levels of the cytokine IL-26 in their blood
Researchers at Karolinska Institutet in Sweden have found a possible new biomarker for COVID-19 after finding increased levels of the cytokine IL-26 in patients with acute COVID-19 infection.
Moreover, high IL-26 levels correlate with an exaggerated inflammatory response that signifies severe disease cases. The findings, which are presented in Frontiers in Immunology, indicate that IL-26 is a potential biomarker for severe COVID-19.
Vaccines for SARS-CoV-2 have been proven effective at reducing the number of cases of severe COVID-19. However, with the emergence of new viral variants, limited vaccine distribution and declining immunity, scientists must find more efficacious treatments for the disease. And this is why the possible discovery of a new biomarker for COVID-19 is such welcome news to the research community.
Groundbreaking research on cytokine interleukin-26 (IL-26) in severe COVID-19
Researchers have tried, for the first time, to ascertain whether immune signalling via the cytokine interleukin-26 (IL-26) is involved in severe COVID-19.
“We need to understand more about underlying immunological mechanisms in order to find better treatments. There is also a need for improved diagnostics in COVID 19-patients,” explains Eduardo Cardenas, postdoc researcher at the Institute of Environmental Medicine, Karolinska Institutet, and principal author of the new pilot study.
“We already know that IL-26 is engaged in mobilising immune cells that combat bacterial infections in the lungs and also in chronic respiratory disease in humans,” adds the study’s last author Anders Lindén, consultant and professor at the Institute of Environmental Medicine, Karolinska Institutet. “What’s more, IL-26 has antiviral and antibacterial effects.”
How was the study conducted?
To study how the molecule is involved in COVID-19, the scientists recruited 49 patients who had been hospitalised with SARS-CoV-2-infection.
The patients were recruited at a hospital in Stockholm from June 2020 to January 2021, and 44 of the study participants had severe symptoms and needed oxygen therapy.
A control group of 27 healthy individuals was also recruited during the same period. The researchers then measured levels of IL-26 protein and other inflammatory compounds in the blood.
“We can show for the first time that blood levels of the cytokine IL-26 are much higher in patients with COVID-19 than in healthy controls,” says Dr Cardenas.
The researchers could also see that the increase was associated with the so-called cytokine storm – an excessive and dangerous inflammatory response that signifies severe cases of COVID-19.
A new potential biomarker and therapeutic target?
“Our discovery gives us a potential biomarker for severe COVID-19, but given the antiviral effects of IL-26, we may also have identified a new therapeutic target,” concludes Professor Lindén.
“Such a study is on the way and can give more information on the clinical value of measuring IL-26 in COVID-patients, such as whether the levels reflect the severity of the disease.”
Dr Cardenas believes that though the results are promising, they are still in the preliminary stages and need further study with a larger patient cohort.
The study was financed by the Swedish Research Council and the Swedish Heart-Lung Foundation.
