title: IL-17 protein levels in both induced sputum and plasma are increased in stable but not acute asthma individuals with obesity.
abstract: Obesity worsens asthma control partly through enhanced airway neutrophilia, altered lung mechanics and comorbidities, including obstructive sleep apnea syndrome, gastroesophageal reflux disease and depression. Although controversial, obesity may also cause poorer outcomes in acute asthma. IL-17 is associated with neutrophilic inflammation, steroid resistance and severe asthma, but its importance in the association between asthma and obesity is unknown.
  
  
  
  To investigate the role of IL-17 in obese asthma in both acute and stable settings.
  
  
  
  Both stable (n = 177) and acute (n = 78) asthmatics were recruited and categorized into lean (n = 77 and 39 respectively), overweight (n = 41 and 17 respectively) and obese (n = 59 and 22 respectively) groups and compared for clinical characteristics, including sputum and plasma IL-17 protein concentrations, sputum cellularity, spirometry and comorbidities. Correlations of IL-17 expression with other measures were explored.
  
  
  
  In stable subjects, airway neutrophilia and IL-17 concentrations were most prominent in the obese, and correlated positively with each other. Significant increase in plasma IL-17 levels was also noted and associated with elevated depressive symptoms in obesity. In acute asthma, IL-17 expression, like most other clinical measures, was similar among lean, overweight and obese groups, but was higher in acute versus stable asthma subjects, with sputum IL-17 correlating positively with sputum neutrophils and negatively with FEV1and plasma IL-17 showing a positive connection to airway eosinophilia during exacerbation.
  
  
  
  IL-17 contributes to worse disease control in obese asthma through enhancing airway neutrophilia and depression, and may implicate in asthma exacerbations. Effects of adiposity on acute asthma remain uncertain.
authors.affiliation: Department of Respiratory Medicine, Xiangya Hospital of Central South University (Key Site of National Clinical Research Center for Respiratory Disease), Changsha 410008, Hunan Province, China; Department of Respiratory Medicine, Huai'an Second People's Hospital, Huai'an 223002, Jiangsu Province, China. Electronic address: 1284530031@qq.com.
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Chen
authors.affiliation: Department of Respiratory Medicine, Xiangya Hospital of Central South University (Key Site of National Clinical Research Center for Respiratory Disease), Changsha 410008, Hunan Province, China. Electronic address: 15152368813@163.com.
authors.forename: Ling
authors.initials: L
authors.lastname: Qin
authors.affiliation: Key Laboratory for Medicinal Exploitation of Huai'an Regional Resource, College of Chemical Engineering, Huaiyin Institute of Technology, Huai'an 223003, Jiangsu Province, China. Electronic address: shiyingying82012@163.com.
authors.forename: Ying-Ying
authors.initials: YY
authors.lastname: Shi
authors.affiliation: Department of Respiratory Medicine, Xiangya Hospital of Central South University (Key Site of National Clinical Research Center for Respiratory Disease), Changsha 410008, Hunan Province, China. Electronic address: 513204423@qq.com.
authors.forename: Jun-Tao
authors.initials: JT
authors.lastname: Feng
authors.affiliation: Department of Respiratory Medicine, Huai'an Second People's Hospital, Huai'an 223002, Jiangsu Province, China. Electronic address: ha183@163.com.
authors.forename: Yu-Long
authors.initials: YL
authors.lastname: Zheng
authors.affiliation: Department of Respiratory Medicine, Huai'an Second People's Hospital, Huai'an 223002, Jiangsu Province, China. Electronic address: ggwanyufeng@163.com.
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Wan
authors.affiliation: Department of Respiratory Medicine, Huai'an Second People's Hospital, Huai'an 223002, Jiangsu Province, China. Electronic address: 657442476@qq.com.
authors.forename: Chuan-Qin
authors.initials: CQ
authors.lastname: Xu
authors.affiliation: Department of Respiratory Medicine, Huai'an Second People's Hospital, Huai'an 223002, Jiangsu Province, China. Electronic address: ha315@163.com.
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: Yang
authors.affiliation: Department of Respiratory Medicine, Xiangya Hospital of Central South University (Key Site of National Clinical Research Center for Respiratory Disease), Changsha 410008, Hunan Province, China. Electronic address: cjh0517@sohu.com.
authors.forename: Cheng-Ping
authors.initials: CP
authors.lastname: Hu
mesh_terms: D000208:Acute Disease; D000328:Adult; D001249:Asthma / Q000150:complications / Q000276:immunology*; D015992:Body Mass Index; D003863:Depression / Q000276:immunology; D005260:Female; D006801:Humans; D020381:Interleukin-17 / Q000032:analysis* / Q000097:blood; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000473:pathology; D009765:Obesity / Q000150:complications / Q000276:immunology*; D050177:Overweight / Q000150:complications / Q000276:immunology; D013183:Sputum / Q000166:cytology / Q000276:immunology*; D013851:Thinness / Q000276:immunology
chemical_list: D020381:Interleukin-17
keywords: Asthma; Depression; Exacerbation; IL-17; Neutrophils; Obesity