title: Effect modification of immunoglobulin E-mediated atopy and rhinitis by glutathione S-transferase genotypes in passive smokers.
abstract: BACKGROUND
  Experimental studies suggest that glutathione S-transferase (GST) genotypes modify nasal allergen responses induced by secondhand smoke (SHS) exposure.
  
  
  OBJECTIVE
  We aimed to investigate whether GSTs affected systemic IgE and allergic rhinitis (AR) in SHS-exposed individuals from a population-based cohort.
  
  
  METHODS
  Analyses comprised 2309 never-smokers from the Swiss study on air pollution and health in adults cohort, reporting SHS status at baseline and 11 years later. Outcomes were defined by total serum IgE≥100 kU/L, specific serum IgE determined by Phadiatop® ≥0.35 kU/L and self-reported AR. GSTP1 Ile105Val, GSTM1 and GSTT1 gene deletion genotypes were identified at the follow-up survey.
  
  
  RESULTS
  After adjustment for relevant covariates, the homozygous GSTP1 105-Val genotype was negatively associated with high total IgE and high-specific IgE by Phadiatop®, notably in subjects persistently exposed to SHS (OR: 0.20, 95% CI 0.05-0.75; P=0.02, for high total IgE and OR: 0.29, 95% CI 0.10-0.89; P=0.03, for high specific IgE by Phadiatop®). Carrying at least one copy of the GSTM1 gene (non-null) showed a similar association for high specific IgE by Phadiatop® (OR: 0.41, 95% CI 0.22-0.76; P=0.004). No significant associations were found between GSTs and rhinitis.
  
  
  CONCLUSIONS
  In this large cohort, homozygosity for GSTP1 105-Val or carrying the GSTM1 non-null genotype decreased the risk of high total IgE or high specific IgE using Phadiatop® by nearly half in subjects exposed to SHS, as compared with subjects carrying opposite alleles. These findings underline the value of genetic susceptibility when evaluating the effects of environmental exposure on allergic illness. The potential long-term effects of persistent SHS exposure in genetically vulnerable individuals may be of public health relevance.
authors: Division of Pulmonary Medicine, University Hospitals of Geneva, Geneva, Switzerland. margaret.gerbase@hcuge.ch
authors: M W
authors: MW
authors: Gerbase
authors: D
authors: D
authors: Keidel
authors: M
authors: M
authors: Imboden
authors: A
authors: A
authors: Gemperli
authors: A
authors: A
authors: Bircher
authors: P
authors: P
authors: Schmid-Grendelmeier
authors: P-O
authors: PO
authors: Bridevaux
authors: W
authors: W
authors: Berger
authors: C
authors: C
authors: Schindler
authors: T
authors: T
authors: Rochat
authors: N
authors: N
authors: Probst-Hensch
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000209:etiology / Q000235:genetics*; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012220:Rhinitis / Q000209:etiology / Q000235:genetics*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution; D007073:Immunoglobulin E; D005982:Glutathione Transferase