It is well known that aspirin-exacerbated respiratory disease (AERD) is more common in women than in men, however, whether gene polymorphisms of the thromboxane A2 receptor (TBXA2R) and chemoattractant receptor-homologous molecules expressed on Th2 cells (CRTH2) are associated with the susceptibility of AERD remains unknown. In this study, we examined the gene polymorphisms in a Japanese population. DNA specimens were obtained from the following three groups: 96 patients with AERD, 500 patients with aspirin-tolerant asthma (ATA) and 100 normal controls. The target DNA sequence of each gene was amplified, and an allelic discrimination assay for single nucleotide polymorphisms relating to expression of each gene was carried out. The frequencies of the CC/CT genotype of TBXA2R +795T>C were higher than those of the TT genotype in AERD patients compared to ATA patients (P=0.015). In female AERD patients, but not in males, frequencies of the CC/CT genotype were higher than those of the TT genotype of TBXA2R +795T>C compared to female ATA patients (P=0.013). Also, frequencies of the TT genotype of CRTH2 -466T>C were higher than those of the CC/CT genotype in AERD patients compared to ATA patients (P=0.034). In female AERD patients, but not in male, frequencies of the TT genotype were higher than those of the CC/CT genotype of CRTH2 -466T>C in AERD patients compared to female ATA patients (P=0.046). Based on our investigations, no significant relationship was found between the genotype and the clinical characteristics according to these gene polymorphisms in AERD patients. Our results suggest that an association between the TBXA2R and CRTH2 gene polymorphisms with AERD may exist in the Japanese population.
Keywords: aspirin-exacerbated respiratory disease; aspirin-tolerant asthma; chemoattractant receptor molecule expressed on Th2 cells; gene polymorphism; thromboxane A2 receptor.