Serum chitinase‐like protein YKL‐40 is linked to small airway function in children with asthmatic symptoms

Abstract

Background: Lung function impairment among asthmatic children begins in early life, and biomarkers for identifying this impairment are needed. The chitinase-like protein YKL-40 has been associated with asthma and lung function in adults, but studies in children have yielded conflicting results. We evaluated the potential of YKL-40 and other systemic biomarkers for identifying lung function deficits in children with asthmatic symptoms. Methods:We determined the levels of serum YKL-40, periostin, and high-sensitivity C-reactive protein (hs-CRP) from the blood samples of 49 children with asthmatic symptoms. Lung function was assessed with impulse oscillometry (IOS) and spirometry, combined with an exercise challenge and a bronchodilator test. Fractional exhaled nitric oxide was measured at multiple flow rates.Results: Serum levels of YKL-40 showed significant correlations with most IOS indices at baseline (P = .008-.039), but there was no association between YKL-40 and spirometry parameters. Neither periostin nor hs-CRP were associated with baseline lung function. Children with a significant response in either the exercise challenge or the bronchodilator test had increased serum levels of YKL-40 (P = .003) and periostin (P = .035). YKL-40 correlated significantly with the blood neutrophil count (r s = .397, P = .005) but was not associated with biomarkers of eosinophilic inflammation. Conclusion:Serum YKL-40 is a potential biomarker for lung function deficits in children with asthmatic symptoms. These deficits appear to be focused on small airways and may remain undetected with spirometry.

Chitinase 3-like-1 protects airway function despite promoting type 2 inflammation during fungal-associated allergic airway inflammation

“…Thus, it is somewhat surprising that, in contrast to the findings in the OVA and HDM models described above, our experiment revealed a contrasting, protective/beneficial role for BRP-39 during fungal asthma. YKL-40 generally correlates with worse disease in human asthma (15,47,52,53). Indeed, we show that YKL-40 levels were elevated in fungal-sensitized asthmatics (Fig.…”

Association of serum periostin levels with clinical features in children with asthma

“…Similarly, Cho et al 20 found significantly higher periostin levels in children with positive exercise and mannitol tests when compared to children with asthma and negative results. Recently, the findings of Knihtilä et al 21 have demonstrated a significant correlation between serum periostin levels, airway hyper‐reactivity, and bronchodilator responsiveness in 49 children with asthmatic symptoms. In our study, we found a significant and independent correlation between asthma severity and serum periostin levels.…”

Chitinase-Induced Airway Hyperreactivity and Inflammation in a Mouse Model of Nonallergic Asthma

“…Lee et al [29] elegantly demonstrated in vitro that the chitinase-like molecule, Chi3l1, binds to the IL-13-receptor α2 and mediates biological responses, including the regulation of cellular apoptosis, oxidative tissue injury, and airway inflammation, thus linking this molecule with Th2-mediated allergic immune responses. Accordingly, serum levels of the chitinase-like protein YKL-40 showed significant correlations with the baseline lung function and were increased in children with a significant response in either the exercise challenge or the bronchodilator test [30]. Consequently, strategies to inhibit the induction of airway inflammation by blocking of chitinases would include attempts to obstruct upstream IL-13 production.…”