SARS-CoV-2 vaccines have been successful in lowering the number of severe COVID-19 cases. However, the emergence of new virus strains, the vaccine’s limited availability, and waning immunity are issues that motivate researchers to discover more effective treatments for the illness.
In this new study, researchers from Sweden’s Karolinska Institutet found that patients suffering from acute COVID-19 infection have higher amounts of the cytokine IL-26 in their blood.
In addition, increased IL-26 levels correlate with an increased inflammatory response, which is indicative of illness severity.
The findings suggest that IL-26 may be a biomarker for severe COVID-19 and are published in Frontiers in Immunology.
SARS-CoV-2 vaccines have been successful in lowering the number of severe COVID-19 cases. However, the emergence of new virus strains, the vaccine’s limited availability, and waning immunity are issues that motivate researchers to discover more effective treatments for the illness.
For the first time, the researchers attempted to determine if immunological signaling via the cytokine interleukin-26 (IL-26) is involved in severe COVID-19.
“We already know,” as explained by author Anders Lindén, “that IL-26 is engaged in mobilising immune cells that combat bacterial infections in the lungs and also in chronic respiratory disease in humans. What’s more, IL-26 has antiviral and antibacterial effects.”
To investigate the role of the molecule in COVID-19, the researchers recruited 49 patients hospitalized for SARS-CoV-2 infection, 44 of whom had severe symptoms and required oxygen therapy.
From June 2020 to January 2021, the patients were picked up at a hospital in Stockholm. During the same time frame, a control group of 27 healthy people was also recruited.
The researchers then looked at how much IL-26 protein and other chemicals that cause inflammation were 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,” points out principal author Dr. Eduardo Cardenas.
The rise was also seen to be related to the so-called cytokine storm, an exaggerated and potentially deadly inflammatory response that marks severe COVID-19 instances, according to the researchers.
The results give “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,” adds Professor Lindén.
Dr. Cardenas says that the results are promising, but they are still early and need to be studied more with a larger group of patients.
“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.”
Source: 10.3389/fimmu.2022.1016991
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