Association of beta2-Adrenergic Receptor Polymorphism with Work-Related Symptoms in Workers Exposed to Wheat Flour

PURPOSE: 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 beta2-adrenergic receptors and wheat-specific antibodies in association with the clinical parameters of baker's asthma. MATERIALS AND 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 beta2-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 (pG 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). CONCLUSION: 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.

Association of beta2-Adrenergic Receptor Polymorphism with the Phenotype of Aspirin-Intolerant Acute Urticaria

The genetic mechanism of aspirin intolerant acute urticaria (AIAU) is unknown. To demonstrate an association between the beta2 adrenergic receptor (ADRB2) polymorphism and the phenotype of AIAU, one hundred fourteen patients with AIAU, 110 patients with aspirin intolerant chronic urticaria (AICU), and 498 normal healthy controls (NC) based on a Korean population were enrolled. The genotype of ADRB2 at 46 A > G was analyzed using a direct sequencing method. The ADRB2 polymorphism at 46 A > G showed a significant difference between AIAU and NC; the frequency of the major genotype was significantly higher in the AIAU group (p= 0.017 in recessive model), while no differences were noted in allele and genotype frequencies between AICU and NC. In conclusion, the ADRB2 (46 A > G) gene polymorphism may contribute to the development of the phenotype of AIAU.