Sputum Neurturin Potential Marker for Airway Inflammation in Asthma

The findings of the study published in Journal of Asthma and Allergy indicate that sputum Neurturin (NRTN) could potentially serve as a novel marker for Type 2 airway inflammation in asthma. Neurturin (NRTN), a neurotrophic factor primarily associated with neural cell development and maintenance, has shown unexpected anti-inflammatory properties in allergic airway conditions, according to recent studies involving NRTN knockout mice.

A group of researchers set out to answer this question, embarking on a study with a dual purpose: first, to confirm the presence of NRTN in human airways, and second, to delve into its clinical and pathogenetic implications in the context of asthma.

The team's methodology involved measuring NRTN levels in induced sputum samples using enzyme-linked immunosorbent assay (ELISA). They then examined the correlations between NRTN and various clinical parameters, including asthma control status and airway inflammation.

Their results, based on 64 asthmatic subjects, were nothing short of remarkable. The study found that all asthmatic participants had detectable levels of NRTN in their sputum, with an average concentration of 2.03 ng/mL. Even more intriguing, sputum NRTN levels exhibited significant positive associations with sputum eosinophil and exhaled nitric oxide levels, pointing towards a role in allergic inflammation. Notably, atopic subjects had significantly higher NRTN levels than their non-atopic counterparts.

However, no significant differences in sputum NRTN levels were observed in relation to asthma control status or asthma exacerbation, suggesting that NRTN's influence might be more closely tied to underlying inflammation rather than acute symptoms.

In an in-depth analysis of sputum inflammation, the study revealed that sputum NRTN levels correlated positively with interleukin (IL)-5 and IL-13 levels, both of which are associated with Type 2 airway inflammation, a hallmark of asthma. Intriguingly, NRTN levels showed a negative correlation with matrix metalloproteinase (MMP)-9, an enzyme linked to airway remodeling.

In summary, this study provides exciting insights into the enigmatic role of NRTN in asthma and may ultimately lead to more effective treatments and improved quality of life for millions of asthma sufferers worldwide.

Source:

Sato, S., Suzuki, Y., Kikuchi, M., Rikimaru, M., Saito, J., & Shibata, Y. (2023). Sputum Neurturin Levels in Adult Asthmatic Subjects. In Journal of Asthma and Allergy: Vol. Volume 16 (pp. 889–901). Informa UK Limited. https://doi.org/10.2147/jaa.s421742