title: Association of β₂-adrenergic receptor polymorphism with work-related symptoms in workers exposed to wheat flour.
abstract: OBJECTIVE
  Our previous study indicated that the presence of wheat-specific IgG1 and IgG4 antibodies was associated with work-related symptoms in workers exposed to wheat flour. We performed this study to investigate the genetic polymorphisms of β₂-adrenergic receptors and wheat-specific antibodies in association with the clinical parameters of baker's asthma.
  
  
  METHODS
  In total, 379 subjects working in a single industrial bakery were enrolled in this study. The skin prick test was performed with common inhalant allergens and wheat flour extract. The presence of serum- specific IgE, IgG1, and IgG4 antibodies to wheat flour were determined by ELISA. Whole blood samples were obtained for genotype analysis. Subjects were genotyped with regard to five candidate single nucleotide polymorphisms (SNPs) of the β₂-adrenergic receptor gene (ADRB2; -47 T>C, 46 A>G, 79 C>G, 252 G>A, and 523 C>A) using a single-base extension method.
  
  
  RESULTS
  No significant associations were observed between the genotype/allele frequencies of any of the SNPs tested and any clinical parameters. The haplotype of ADRB2 (GAA composed of 46 A>G, 252 G>A, and 523 C>A) was significantly associated with work-related symptoms (p<0.05). Moreover, in subjects with the AG or GG genotype at 46 A>G and haplotype [GAA] of ADRB2, the prevalence rates of wheat-specific IgG1 antibodies and lower respiratory symptoms increased significantly with exposure intensity (both p<0.05).
  
  
  CONCLUSIONS
  The findings of the present study suggest that ADRB2 genetic polymorphism may contribute to the development of work-related symptoms in workers exposed to wheat flour, which can lead to baker's asthma.
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Gyu-Young
authors.initials: GY
authors.lastname: Hur
authors.forename: Han-Jung
authors.initials: HJ
authors.lastname: Park
authors.forename: Hyun-Young
authors.initials: HY
authors.lastname: Lee
authors.forename: Dong-Hee
authors.initials: DH
authors.lastname: Koh
authors.forename: Byung-Jae
authors.initials: BJ
authors.lastname: Lee
authors.forename: Gil-Soon
authors.initials: GS
authors.lastname: Choi
authors.forename: Seung-Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Ye
authors.forename: Hae-Sim
authors.initials: HS
authors.lastname: Park
mesh_terms: D000328:Adult; D000485:Allergens / Q000276:immunology*; D001249:Asthma / Q000235:genetics / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005433:Flour; D006239:Haplotypes; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D019570:Inhalation Exposure / Q000032:analysis; D008297:Male; D016273:Occupational Exposure / Q000032:analysis; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics*; D012882:Skin Tests; D014908:Triticum / Q000276:immunology*
chemical_list: D000485:Allergens; D007074:Immunoglobulin G; D018343:Receptors, Adrenergic, beta-2