Abstract
Background: IL33 is an important cytokine in the pathogenesis of asthma, and associations of IL33 gene polymorphisms with asthma have been suggested by several genome-wide analyses. However there are no studies regarding the association of IL33 with adult-onset asthma.
Objective: To investigate if IL33 single-nucleotide polymorphisms (SNPs) associate with the risk of developing adult-onset asthma.
Methods: This was a population-based incident case-control study of clinically defined adult-onset asthma and randomly drawn controls, conducted among adults 21 to 63 years old, from a geographically defined area in South Finland. Altogether 521 cases of asthma and 1,016 randomly selected controls participated (response rates 86% and 80%, respectively). A total of 16 tagging SNPs in IL33 locus were genotyped for 467 new adult-onset asthma cases and 613 disease-free controls to whom a DNA sample was available. Additive genetic association with adult-onset asthma was tested using PLINK v1.07.
Results: Four IL33 SNPs associated with adult-onset asthma in additive genetic model adjusted for age, sex, education, pets, smoking, and second-hand smoke. Adjusted ORs (95% CIs) were: 1.995 (1.194-3.333, p=0.008) for rs996029 A allele, 1.296 (1.045-1.607, P=0.018) for rs2006682 G allele, 1.682 (1.126-2.513, p=0.011) for rs7037276 G allele, and 2.073 (1.192-3.605, p=0.010) for rs1412420 A allele. Further adjusting for atopy strengthened the associations (p-values 0.003, 0.011, 0.004, and 0.006, respectively).
Conclusions: This is the first study to show association of IL33 polymorphisms with adult-onset asthma. These associations may be modified by atopic status of the individuals.
- Copyright ©ERS 2015
