Effect of Variation in CHI3L1 on Serum YKL-40 Level, Risk of Asthma, and Lung Function

The chitinase-like protein YKL-40 is known to be involved in inflammation and tissue remodeling and is a biomarker of asthma severity and pulmonary function. This study shows an association between markers in the gene encoding YKL-40 and asthma, indicating that YKL-40 levels not only serve as a biomarker but also contribute to disease susceptibility. This study shows an association between markers in the gene encoding YKL-40 and asthma, indicating that YKL-40 levels not only serve as a biomarker but also contribute to disease susceptibility. Chitinases are evolutionarily conserved proteins that mediate airway inflammation in mouse models of asthma. 1 The chitinase-like protein YKL-40 lacks chitinase activity but binds ubiquitously expressed chitin and has been implicated in inflammation and tissue remodeling. 2 – 6 We recently demonstrated that serum YKL-40 levels are elevated in patients with asthma and that circulating YKL-40 levels are correlated with asthma severity, thickness of the subepithelial basement membrane, and pulmonary function, 7 suggesting that circulating YKL-40 levels are a biomarker for asthma. The YKL-40 protein is encoded by the chitinase 3–like 1 gene CHI3L1, and single-nucleotide polymorphisms (SNPs) in the CHI3L1 promoter have been . . .