Association between antibiotic exposure, bronchiolitis, and TLR4 (rs1927911) polymorphisms in childhood asthma

• Main Authors: Eun Lee, Ji Won Kwon, Hyo Bin Kim, Ho Sung Yu, Mi Jin Kang, Kyungmo Hong, Song I. Yang, Young Ho Jung, Seung Hwa Lee, Kil Young Choi, Hye Lim Shin, Seo Ah Hong, Hyung Young Kim, Ju Hee Seo, Byoung Ju Kim, So Yeon Lee, Dae Jin Song, Woo Kyung Kim, Gwang Cheon Jang, Jung Yeon Shim, Soo Jong Hong
• Other Authors: University of Ulsan, College of Medicine
• Format: Article
• Published: 2018
• Subjects: Immunology and Microbiology; Medicine
• Online Access: https://repository.li.mahidol.ac.th/handle/123456789/34112
• Institution: Mahidol University

© Copyright The Korean Academy of Asthma, Allergy and Clinical Immunology. The complex interplay between environmental and genetic factors plays an important role in the development of asthma. Several studies have yielded conflicting results regarding the 2 asthma-related risk factors: antibiotic usage during infancy and/or a history of bronchiolitis during early life and the development of asthma. In addition to these risk factors, we also explored the effects of Toll-like receptor 4 (TLR4) polymorphism on the development of childhood asthma. Methods: This cross-sectional study involved 7,389 middle school students who were from 8 areas of Seoul, Korea, and completed the International Study of Asthma and Allergies in Childhood questionnaire. The TLR4 polymorphism rs1927911 was genotyped in 1,395 middle school students from two areas using the TaqMan assay. Results: Bronchiolitis in the first 2 years of life, antibiotic exposure during the first year of life, and parental history of asthma were independent risk factors for the development of asthma. When combined, antibiotic use and a history of bronchiolitis increased the risk of asthma (adjusted odds ratio [aOR]: 4.64, 95% confidence interval [CI]: 3.09-6.97, P value for interaction=0.02). In subjects with CC genotype of TLR4, antibiotic exposure and a history of bronchiolitis during infancy, the risk of asthma was increased, compared to subjects without these risk factors (aOR: 5.72, 95% CI: 1.74-18.87). Conclusions: Early-life antibiotic exposures and a history of bronchiolitis are risk factors for asthma in young adolescents. Polymorphisms of TLR4 modified the influence of these environmental factors. Reducing antibiotic exposure and preventing bronchiolitis during infancy may prevent the development of asthma, especially in genetically susceptible subjects.