Protein in the nose provides information about COPD

Chronic obstructive pulmonary disease (COPD) affects ten percent of the world population and is the fourth leading cause of death globally. It is primarily caused by biomass smoke, produced for instance by burning wood or animal dung for heat. Patients exhibit diverse symptoms and prognoses, necessitating individualized and simple diagnostic methods.

Researchers at CMM, Karolinska Institutet and Karolinska University Hospital have discovered that elevated levels of interleukin-26 (IL-26) in the noses of smokers, both with and without COPD, can help assess early-stage COPD. IL-26 is a cytokine crucial for immune cell communication and has direct inhibitory effects on bacteria and viruses. It has been linked to various inflammatory diseases, including COPD, where its levels are elevated in the lower respiratory tract.

The study, published in the Journal of Allergy and Clinical Immunology, focused on IL-26 production in the noses of smokers and its implications for individual COPD patients.

“We have discovered that IL-26 is produced in greater amounts in the nose of smokers with COPD compared to non-smokers, while smokers without COPD showed a tendency towards increased levels. This suggests that IL-26 may be an important factor in the inflammatory process underlying COPD,” says the study’s first author Julia Arebro, researcher at the Department of Clinical Science, Intervention and Technology, Karolinska Institutet, and physician at Karolinska University Hospital.

The study involved 50 participants: habitual smokers with and without COPD, and healthy non-smokers, excluding those with other lung diseases. Participants underwent nasal lavage to measure IL-26 levels in the nose. Among other things, the study participants underwent a simple nasal lavage so that the researchers could analyse the presence of IL-26 in the nose.

The measured levels were found to reflect inflammation of the lower respiratory tract but also symptoms and other clinical findings in COPD.

This method offers a simpler way to characterize COPD patients without invasive, resource-intensive procedures. The study also found that T cells in the nose produce IL-26.

“Our results support that IL-26 contributes to the chronic inflammation that is typical for COPD. This may open up for new treatment strategies that target IL-26 to reduce inflammation and improve the quality of life for patients with COPD,” says Anders Lindén, CMM Group Leader, professor at the Institute of Environmental Medicine, Karolinska Institutet, and senior physician at Karolinska University Hospital who has led the research team behind the study.

The study was conducted on patients with mild to moderate COPD. Future research will focus on later stages of COPD to confirm these findings and potentially implement this diagnostic method within a few years.

The study was funded by the Swedish Heart-Lung Foundation, the Swedish Research Council, Region Stockholm (ALF funding), the Swedish Society for Respiratory Medicine, and AstraZeneca. The researchers report no conflicts of interest.