There is still a lack of comprehensive treatment methods for Covid-19. A research team in Sweden is following one approach and identifying a possible biomarker for a severe course. This is where diagnostics and treatment can start.
A research team from the Karolinska Institute in Sweden has detected elevated levels of the cytokine interleukin-26 (IL-26) in the blood of patients with acute Covid-19 disease. It is known from earlier research that high IL-26 levels are associated with an excessive inflammatory reaction, which often results in severe disease progression. The phenomenon became known under the name cytokine storm. From this they conclude that IL-26 is a potential biomarker for severe Covid-19. The researchers published their results in the journal Frontiers in Immunology.
To investigate how the IL-26 is involved in Covid-19, 49 patients who had been admitted with a Sars-CoV-2 infection were recruited at a hospital in Stockholm from June 2020 to January 2021. 44 of them had severe symptoms and required oxygen therapy. The control group consisted of 27 healthy people over the same period. Blood levels of IL-26 protein and other inflammatory compounds were measured in both groups.
“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. Edward Cardenas. The lead author of the study works at the Institute of Environmental Medicine at Karolinska Institutet.
It is already known from previous research that IL-26 “is involved in the mobilization of immune cells that fight bacterial infections in the lungs and also in chronic respiratory diseases in humans,” explains Anders Lindén, who was involved in the study. “In addition, IL-26 has an antiviral and antibacterial effect.”
In the current study, the scientists were able to prove that the increase in IL-26 was associated with the so-called cytokine storm. The excessive and dangerous inflammatory response points to severe cases of Covid-19. “Our discovery gives us a potential biomarker for severe Covid-19, but given the antiviral effects of IL-26, we may have also identified a new therapeutic target,” says Professor Lindén.
Because although the vaccines have proven effective in reducing the number of severe Covid cases, there are still few treatment options for the disease. “We need to better understand the underlying immunological mechanisms in order to find better treatments. There is also a need for improved diagnostics in Covid-19 patients,” says Cardenas. He is now preparing a study with a larger patient group to gather more information on the clinical value of measuring IL-26 in Covid patients. Then it may be possible to answer whether the values reflect the severity of the disease.