title: Probable role of Beta 2-adrenergic receptor gene haplotype in toluene diisocyanate-induced asthma.
abstract: OBJECTIVE
  A genetic polymorphism of the beta 2-adrenergic receptor is a major factor associated with the asthmatic phenotype. The association of this polymorphism with toluene diisocyanate (TDI)-induced asthma has not been investigated. We examined 103 TDI-induced asthma patients (TDI-OA), 60 asymptomatic exposed controls (AEC), and 263 unexposed healthy controls (NC) in order to identify beta 2-adrenergic receptor gene (ADRB2) polymorphisms and the possible association with TDI-induced asthma.
  
  
  METHODS
  Single nucleotide polymorphisms (SNPs) of ADRB2 were genotyped by direct sequencing. Serum-specific IgE and IgG levels were measured using an enzyme-linked immunosorbent assay. Phenotypes and clinical patient parameters were compared.
  
  
  RESULTS
  SNPs were identified (-47 T>C, -20 T>C, Arg16Gly A>G, Gln27Glu C>G, Leu134Leu G>A, Arg175Arg C>A) during ADRB2 screening (from -231 to 793 bp). No significant differences in allelic and genotypic frequencies were noted for any of the six ADRB2 SNPs. The Arg16Gly A>G, Leu134Leu G>A, and Arg175Arg C>A SNPs and haplotype 1 [TTACGC] were significantly associated with specific IgE antibodies to the TDI-human serum albumin (HSA) conjugate in TDI-exposed subjects (P<0.05). Exposed workers with the ADRB2 ht1/ht1 homozygote had a significantly higher TDI-HSA conjugate-specific IgE sensitization rate than did those with the null ht1 haplotype (odds ratio, 15.40; 95% confidence interval, 1.81-131.06).
  
  
  CONCLUSIONS
  ADRB2 polymorphisms may affect IgE-specific sensitization to TDI-HSA conjugate in TDI-exposed workers.
authors.affiliation: Department of Allergy & Rheumatology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Ye
authors.forename: Young-Mi
authors.initials: YM
authors.lastname: Kang
authors.forename: Seung-Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Hyun-Young
authors.initials: HY
authors.lastname: Lee
authors.forename: Cheol Woo
authors.initials: CW
authors.lastname: Kim
authors.forename: Choon-Sik
authors.initials: CS
authors.lastname: Park
authors.forename: Chein-Soo
authors.initials: CS
authors.lastname: Hong
authors.forename: Hae-Sim
authors.initials: HS
authors.lastname: Park