Reduced levels of the CC16 protein in bronchoalveolar lavage and serum are associated with asthma susceptibility. Researchers, led by Xingnan Li, examined CC16 mRNA expression levels in non-ciliated bronchial epithelial cells (BEC) for any associations with asthma severity. The researchers concluded that CC16 mRNA expression levels in BEC were associated with asthma susceptibility, severity, and exacerbations via immunomodulation of T2 inflammation.
The study, published in the American Journal of Respiratory and Critical Care Medicine, enrolled 242 patients with asthma and 69 healthy controls. Researchers used a generalized linear model to assess associations between CC16 mRNA expression levels and asthma phenotypes in the Severe Asthma Research Program (SARP).
CC16 mRNA Expression and Asthma Susceptibility
According to the researchers, low CC16 mRNA expression in BEC was significantly associated with asthma susceptibility and severity, high use of systemic corticosteroids, high retrospective and prospective asthma exacerbations, and low pulmonary function.
Additionally, low expression of CC16 was significantly associated with high fractional exhaled nitric oxide and sputum eosinophils, both biomarkers for T2 inflammation. CC16 mRNA expression also negatively correlated with expression levels of Th2 genes and positive correlated with expression levels of Th1 and inflammation genes. Researchers noted that two non-T2 biomarkers, CC16 and IL-6, characterized four asthmatic endotypes with different features of T2 inflammation, obesity, and asthma severity.
In short, the study’s authors concluded that CC16 was associated with asthma severity, and they further suggested it was “a potential non-T2 biomarker for asthma development and progression.”