Beta 2 Adernergic receptor gene polymorphisms in Korean TDI-induced asthmatics

초록

Background: TDI is the most prevalent cause of occupational asthma, however, there has been no study for evaluation the association of beta 2 adrenergic receptor gene (ADRB2) polymorphisms with TDI-induced asthma. Objective: To identify ADRB2 polymorphisms and evaluate their association with clinical characteristics of TDI-induced asthma, 64 TDI-induced asthma patients (TDI), 47 asymptomatic exposed controls (AECs), and 72-unexposed healthy controls (NC) were enrolled. Method: SNPs of ADRB2 were genotyped using the direct sequencing method. We compared bronchial hyper-reactivity and serum specific IgE and IgG to TDI-HSA conjugate according to the genetype of ADRB2 in patiens with TDI-induced asthma. Result: Through a screening of ADRB2 from -231bp to 793 bp, six SNPs (-47T>C, -20T>C, 46A>G, 79C>G, 252G>A, 523G>T) were found. While no significant differences in allele and genotype frequencies of all six SNPs of ADRB2 were noted among the three groups (p>0.05, respectively), 6-SNP haplotype, ht1{TTACGC} was associated with increased disease risk among exposed subjects including TDI and AEC (OR=1.834, p=0.04). Moreover, both of 252G>A and 523 C>A showed significant association with bronchial hyper-reactivity to methacholine in a dominant analysis model (p<0.05). Conclusion: ADRB2 polymorphisms might contribute to determine airway hyperesponsiveness and the phenotype of TDI-induced asthma.