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

Area of Science:

• Pediatric Pulmonology
• Biomarkers in Respiratory Disease
• Asthma Research

Background:

• Lung function impairment in asthmatic children starts early, necessitating reliable biomarkers.
• Previous studies on YKL-40 in pediatric asthma and lung function have shown inconsistent results.
• This study investigates YKL-40 and other systemic markers for detecting lung function deficits in children with asthma symptoms.

Purpose of the Study:

• To evaluate serum YKL-40 as a potential biomarker for lung function deficits in children with asthmatic symptoms.
• To explore the association of YKL-40, periostin, and hs-CRP with lung function parameters in pediatric asthma.
• To determine if YKL-40 can identify deficits in small airways that spirometry might miss.

Main Methods:

• Serum levels of YKL-40, periostin, and high-sensitivity C-reactive protein (hs-CRP) were measured in 49 children with asthmatic symptoms.
• Lung function was assessed using impulse oscillometry (IOS) and spirometry, alongside exercise and bronchodilator challenges.
• Fractional exhaled nitric oxide was measured at various flow rates.

Main Results:

• Serum YKL-40 levels correlated significantly with most baseline IOS indices (P=.008-.039) but not with spirometry parameters.
• Periostin and hs-CRP showed no association with baseline lung function.
• Children exhibiting significant responses to exercise or bronchodilator challenges had elevated serum YKL-40 (P=.003) and periostin (P=.035) levels.
• YKL-40 correlated with neutrophil count (rs=.397, P=.005) but not with eosinophilic inflammation markers.

Conclusions:

• Serum YKL-40 shows promise as a biomarker for detecting lung function deficits in children with asthmatic symptoms.
• These identified deficits appear to primarily affect small airways.
• YKL-40 may help identify lung function impairments that are not detectable by standard spirometry.