title: IL-33 promotes airway remodeling and is a marker of asthma disease severity.
abstract: OBJECTIVE
  To investigate the function of interleukin-33 (IL-33) in the asthmatic airway remodeling and the relationship between IL-33 and asthma severity.
  
  
  METHODS
  IL-33 levels, sputum eosinophils percentage (EOS%), pulmonary function and total immunoglobulin (IgE) were measured for 45 patients with asthma and 40 non-allergic controls. Asthma severity was assessed. The expressions of IL-33 and reticular basement membrane (RBM) on bronchial biopsy specimens from eight asthma patients and eight non-allergic controls were observed after hematoxylin-eosin staining (HE) and immunohistochemical staining. In vitro experiments, real-time polymerase chain reactions and western blotting analysis were used to identify the specific effects of IL-33 administration.
  
  
  RESULTS
  Serum IL-33 levels in patients with asthma were higher than those in non-allergic controls. Moreover, in asthmatic patients, serum IL-33 levels were negatively correlated to forced expiratory volume in one second (FEV1, % predicted), and positively correlated to asthma severity. Increased expression of IL-33 and RBM thickening were observed on bronchial biopsy specimens obtained from patients with asthma. Serum IL-33 levels were positively correlated to basement membrane thickness. The production of fibronectin1 and type I collagen in human lung fibroblasts (HLF-1) increased at 24 h after IL-33 treatment in vitro. Pre-treatment with anti-ST2 antibody or fluticasone propionate (FP) suppressed the production of fibronectin1 and types I collagen induced by IL-33.
  
  
  CONCLUSIONS
  IL-33 is a marker of asthma severity, and may contribute to airway remodeling in asthma by acting on human lung fibroblasts.
authors.affiliation: Department of Pulmonary Medicine, Qilu Hospital of Shandong University , Jinan , China .
authors.forename: Zhi
authors.initials: Z
authors.lastname: Guo
authors.forename: Jinxiang
authors.initials: J
authors.lastname: Wu
authors.forename: Jiping
authors.initials: J
authors.lastname: Zhao
authors.forename: Fen
authors.initials: F
authors.lastname: Liu
authors.forename: Yingjian
authors.initials: Y
authors.lastname: Chen
authors.forename: Liquan
authors.initials: L
authors.lastname: Bi
authors.forename: Shuying
authors.initials: S
authors.lastname: Liu
authors.forename: Liang
authors.initials: L
authors.lastname: Dong
mesh_terms: D000328:Adult; D056151:Airway Remodeling / Q000502:physiology*; D001249:Asthma / Q000097:blood* / Q000503:physiopathology*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D000067596:Interleukin-33; D007378:Interleukins / Q000097:blood* / Q000502:physiology*; D008297:Male; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; C506536:IL33 protein, human; D000067596:Interleukin-33; D007378:Interleukins
keywords: Airway remodeling; HLF-1; IL-33; ST2; asthma