Study of serum YKL-40 in children with bronchial asthma

BackgroundSerum YKL-40 (chitinase-3-like-1) has recently been found to be either the cause or a biomarker for asthma. This study quantifies serum levels of YKL-40 in asthmatic children and evaluates the relationship between YKL-40 and asthma severity.MethodsWe quantified serum YKL-40 levels in two groups of asthmatic children (aged between 2 and 12 years). Group 1 (n: 30) in between the attack (stable group) and group 2 (n: 30) during the exacerbation (acute attack group). Serum YKL-40 was measured by enzyme-linked immunosorbent assay (ELIZA) Kits (WKEA MED SUPPLIES CORP). We measured blood eosinophils and peak expiratory flow rate for children >5 years.ResultsSerum levels of YKL-40 were significantly elevated in the acute asthma group and in the stable asthma group compared to the control group (673.92 ± 24.23 ng/ml, 552.73 ± 57.34 ng/ml, 136.17 ± 53.14) respectively, P < 0.001. YKL-40 levels were correlated positively with blood eosinophils in the stable group (ρ = 0.67, P < 0.001) and in the acute attack group (ρ = 0.76, P < 0.001). It is inversely correlated with PEFR in the stable asthma group (ρ = −0.83, P < 0.001) and in the acute asthma group (ρ = −0.88, P < 0.001).ConclusionsSerum YKL-40 protein was found in increased quantities in patients with asthma in whom the protein level correlated positively with the severity of disease so our data concluded that YKL-40 could be a valuable biomarker for asthma diagnosis and prognosis.