CHI3L1 polymorphisms, cord blood YKL-40 levels and later asthma development

BMC Pulm Med. 2016 May 18;16(1):81. doi: 10.1186/s12890-016-0239-8.


Background: Single nucleotide polymorphisms (SNPs) in chitinase 3-like 1 (CHI3L1), the gene encoding YKL-40, and increased serum YKL-40 levels are associated with severe forms of asthma. It has never been addressed whether SNPs in CHI3L1 and cord blood YKL-40 levels could already serve as potential biomarkers for milder forms of asthma. We assessed in an unselected population whether SNPs in CHI3L1 and cord blood YKL-40 levels at birth are associated with respiratory symptoms, lung function changes, asthma, and atopy.

Methods: In a prospective birth cohort of healthy term-born neonates (n = 260), we studied CHI3L1 polymorphisms, and measured cord blood YKL-40 levels by ELISA in (n = 170) infants. Lung function was performed at 5 weeks and 6 years. Respiratory health during the first year of life was assessed weekly by telephone interviews. Diagnosis of asthma and allergic sensitisation was assessed at 6 years (n = 142).

Results: The SNP rs10399805 was significantly associated with asthma at 6 years. The odds ratio for asthma was 4.5 (95 % CI 1.59-12.94) per T-allele. This finding was unchanged when adjusting for cord blood YKL-40 levels. There was no significant association for cord blood YKL-40 levels and asthma. SNPs in CHI3L1 and cord blood YKL-40 were not associated with lung function measurements at 5 weeks and 6 years, respiratory symptoms in the first year, and allergic sensitisation at 6 years.

Conclusion: Genetic variation in CHI3L1 might be related to the development of milder forms of asthma. Larger studies are warranted to establish the role of YKL-40 in that pathway.

Keywords: Asthma; CHI3L1 protein; Children; Cohort study; Cord blood; Genetic association study; Genetic variation; Infants; YKL-40 protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Asthma / blood*
  • Asthma / genetics*
  • Biomarkers / blood
  • Child
  • Chitinase-3-Like Protein 1 / blood*
  • Chitinase-3-Like Protein 1 / genetics
  • Female
  • Fetal Blood / metabolism
  • Genetic Predisposition to Disease
  • Humans
  • Hypersensitivity, Immediate
  • Infant, Newborn
  • Linear Models
  • Male
  • Polymorphism, Single Nucleotide
  • Promoter Regions, Genetic
  • Prospective Studies
  • Respiratory Function Tests
  • Risk Factors
  • Switzerland


  • Biomarkers
  • CHI3L1 protein, human
  • Chitinase-3-Like Protein 1