Association of beta2-adrenoreceptor polymorphisms with nocturnal cough among atopic subjects but not with atopy and nonspecific bronchial hyperresponsiveness.

BACKGROUND

The reports from in vitro studies that beta(2)-adre-nergic receptor (B2AR) polymorphisms are associated with agonist-promoted downregulation have evoked considerable research interest for the roles of these polymorphisms to the pathogenesis of asthma.

OBJECTIVE

We sought to evaluate the association between asthma phenotypes and B2AR polymorphisms at 2 sites (Arg16 --> Gly16 and Gln27 --> Glu27) in the general population.

METHODS

Four hundred forty unrelated Korean adults were randomly selected, and asthma phenotypes were determined with a questionnaire, immunoassay, skin prick testing, and methacholine bronchial provocation testing. Genotypes of B2AR polymorphisms were determined with PCR-based methods.

RESULTS

No significant association was found between B2AR alleles and haplotypes and total IgE levels, skin test responses to aeroallergens, and bronchial responsiveness to methacholine. Among the atopic subjects, however, numbers of both Arg16 alleles and Arg16-Gln27 haplotypes were negatively associated with nocturnal cough, and in contrast, Gly16-Gln27 was positively associated with it.

CONCLUSION

B2AR polymorphisms may play an important role in the expression of nocturnal cough in atopic subjects but not in the expression of atopy and bronchial hyperresponsiveness in a general population.