Traffic‐related air pollution induces non‐allergic eosinophilic airway inflammation and cough hypersensitivity in guinea‐pigs

• Published in: Clinical and experimental allergy 2019-03, Vol.49 (3), p.366-377
• Main Authors: Fang, Zhangfu, Huang, Chuqin, Zhang, Junfeng (Jim), Xie, Jiaxing, Dai, Shouhui, Ge, Erjia, Xiang, Juan, Yao, Hongmei, Huang, Rongquan, Bi, Xinhui, Wang, Boguang, Zhong, Nanshan, Lai, Kefang
• Format: Article
• Language: English
• Subjects: Air pollution; Air Pollution - adverse effects; Air pollution measurements; airway inflammation; Allyl isothiocyanate; Alveoli; Animals; Asthma; Bronchi - immunology; Bronchi - pathology; Bronchitis; Bronchoalveolar Lavage Fluid; Bronchus; Citric acid; Cough; Cough - chemically induced; Cough - immunology; Cough - pathology; cough hypersensitivity; Counting; Dexamethasone; Environmental Exposure - adverse effects; eosinophil; Eosinophilia; Eosinophilia - chemically induced; Eosinophilia - immunology; Eosinophilia - pathology; Eosinophils - immunology; Eosinophils - pathology; Exposure; Female; Guinea Pigs; Histopathology; Hypersensitivity; Hypersensitivity - immunology; Hypersensitivity - pathology; Inflammation; Isothiocyanate; Leukocytes (eosinophilic); Leukocytes (neutrophilic); Lungs; Male; Pollution; Respiratory tract; Respiratory tract diseases; Swine; Trachea; Traffic; Traffic-Related Pollution - adverse effects; traffic‐related air pollution
• ISSN: 0954-7894; 1365-2222
• DOI: 10.1111/cea.13308

Background The pathogenesis and pathophysiology of eosinophilia‐related chronic cough such as non‐asthmatic eosinophilic bronchitis and cough variant asthma are still not clear. Objective This study is to examine the potential role of traffic‐related air pollution (TRAP) in eosinophilic inflammation and cough responses. Methods Non‐sensitized guinea‐pigs were exposed to TRAP in an urban traffic tunnel or kept in a filtered air environment for 7 or 14 days. Reflexive cough was measured using citric acid and allyl isothiocyanate (AITC) challenges, respectively. Spontaneous cough counting was determined using audio recording and a waveform analysis. Airway inflammation was evaluated using differential cells in bronchoalveolar lavage fluid (BALF) and lung histopathology. To further elucidate the relationship between airway inflammation and cough hypersensitivity, a subgroup of those exposed for 14 days received a dexamethasone treatment. Results Compared to reflexive cough count (mean (95% confidence interval) in 10 minutes) provoked by the AITC challenge for the unexposed animals (3.1 (1.7‐4.5)), those were increased significantly following both the 7‐day (12.0 (6.8‐17.2), P