title: A polymorphism in the promoter region of the human interleukin-16 gene is not associated with asthma or atopy in an Australian population.
abstract: BACKGROUND
  IL-16 is an immunomodulatory cytokine whose expression is increased in the bronchial mucosa, bronchoalveolar lavage fluid and induced sputum of asthmatic patients. It has been suggested that IL-16 has a regulatory role in the pathophysiology of asthma. A single-nucleotide polymorphism (T(-295)C) has been described in the promoter region of the gene and it has been hypothesized that this polymorphism may be associated with altered levels of IL-16 expression, and account for the increased levels of IL-16 seen in the asthmatic airway.
  
  
  OBJECTIVE
  To determine the association between the T(-295)C promoter polymorphism and asthma, disease severity and atopy in a large Australian Caucasian population.
  
  
  METHODS
  We used PCR and restriction fragment length polymorphism analysis to establish the allele frequency of the T(-295)C promoter polymorphism in a random Australian Caucasian population (n=176) and to characterize the polymorphism in a large Australian Caucasian population of mild (n=273), moderate (n=230) and severe (n=77) asthmatic patients, and non-asthmatic controls (n=455). Genotype association analyses were performed using chi(2) tests.
  
  
  RESULTS
  The polymorphic C allele was present in 19% of the asthmatic population and 21% of the non-asthmatic population. There was no association between the polymorphism and asthma (P=0.153) nor with asthma severity (P=0.417) or atopy (P=0.157) in this population.
  
  
  CONCLUSIONS
  Although it has been hypothesized that the T(-295)C promoter polymorphism may be associated with increased IL-16 gene expression, it is not associated with asthma, disease severity or atopy in this Australian population.
authors.affiliation: The Asthma and Allergy Research Institute Inc., Nedlands, WA, Australia.
authors.forename: L S
authors.initials: LS
authors.lastname: Akesson
authors.forename: D L
authors.initials: DL
authors.lastname: Duffy
authors.forename: S C
authors.initials: SC
authors.lastname: Phelps
authors.forename: P J
authors.initials: PJ
authors.lastname: Thompson
authors.forename: M-A
authors.initials: MA
authors.lastname: Kedda
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D001249:Asthma / Q000208:ethnology / Q000235:genetics*; D001315:Australia; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D006801:Humans; D006967:Hypersensitivity / Q000235:genetics*; D019410:Interleukin-16 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D044465:White People
chemical_list: D019410:Interleukin-16