Motohiro Kurosawa, Eijin Sutoh and Yujin Sutoh
Background: Chronic obstructive pulmonary disease (COPD) and bronchial asthma might have common genetic factors. Interleukin 13 (IL-13) gene polymorphism has been suggested to be one of the candidates; however inconsistent results have been reported. Studies of the gene polymorphisms in IL-17A gene and mast cell chymase gene (CMA1) in COPD and bronchial asthma have not been reported. Methods: The single nucleotide polymorphisms in IL-13 -1111C>T, IL-13 Arg130Gln, IL-17A -737C>T, and CAM1 -1903G>A genes were examined in 100 COPD patients, 250 asthmatics and 100 normal control. All patients were Japanese who were in a stable condition. Results: The frequency of TT/CT genotype of the IL-13 -1111C>T was higher than that of CC genotype in COPD patients compared with asthmatics. Subgroup analyses with gender showed that in female COPD patients the frequency of TT/CT genotype of the IL-13 -1111C>T was higher than that of CC genotype compared with female asthmatics. The frequency of TT/CT genotype of the IL-17A -737C>T was lower than that of CC genotype in COPD patients compared with asthmatics. Subgroup analyses with gender showed that in male COPD patients the frequency of TT/CT genotype of the IL-17A -737C>T was lower than that of CC genotype compared with male asthmatics. The frequency of AA/GA and GG genotypes of the CMA1 -1903G>A in COPD patients did not differ from that of asthmatics. Asthmatics with CC genotype of the IL-13 Arg130Gln showed higher levels of total serum IgE than that of the patients with TT/CT genotype. Conclusion: This study suggested the IL-13 -1111C>T and IL-17A -737C>T gene sequence variations might have a role in COPD and asthma in a Japanese population.