title: YKL-40 expression in chronic obstructive pulmonary disease: relation to acute exacerbations and airway remodeling.
abstract: BACKGROUND
  Recent studies suggest that YKL-40, also called chitinase-3-like-1 protein, has been implicated in the pathogenesis of various inflammatory diseases. It is currently unknown, however, whether YKL-40 plays a role in acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and airway remodeling.
  
  
  METHODS
  We evaluated serum YKL-40 levels in patients with AECOPD (n = 37) and stable COPD (n = 44), as well as in controls (n = 47). The association between YKL-40 expression and airway remodeling was analyzed. The effects of YKL-40 on collagen synthesis of primary human lung fibroblasts were also evaluated.
  
  
  RESULTS
  Serum YKL-40 levels were elevated at AECOPD onset as compared to stable disease (median [interquartile range], 78.6 [52.3-122.2] ng/ml versus 46.7 [31.2-75.5] ng/ml; p = 0.0005). The ideal cutoff point for distinguishing patients with AECOPD from those with stable COPD was 64.7 ng/ml (AUC: 0.71; 95%CI: 0.596 to 0.823). YKL-40 expression correlated with airflow obstruction, C-reactive protein, and collagen deposition. Stimulation with YKL-40 promoted collagen production in lung fibroblasts through ERK- and p38-dependent mechanisms.
  
  
  CONCLUSIONS
  YKL-40 expression is up-regulated in patients with COPD and correlates with exacerbation attacks and may contribute to airway remodeling by acting on lung fibroblasts. The current data may provide insight into the underlying pathogenesis of COPD, in which YKL-40 has an important pathogenic role.
  
  
  BACKGROUND
  ChiCTR-OCC-13003567.
authors.affiliation: Department of Respiratory and Critical Care Medicine, Affiliated Hospital, Institute of Respiratory Diseases, Guangdong Medical College, Zhanjiang, China.|Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital, Institute of Respiratory Diseases, Zhejiang University School of Medicine, Hangzhou, China.
authors.forename: Tianwen
authors.initials: T
authors.lastname: Lai
authors.affiliation: Department of Respiratory and Critical Care Medicine, Affiliated Hospital, Institute of Respiratory Diseases, Guangdong Medical College, Zhanjiang, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wu
authors.affiliation: Department of Respiratory and Critical Care Medicine, Affiliated Hospital, Institute of Respiratory Diseases, Guangdong Medical College, Zhanjiang, China.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Respiratory Medicine, Ningbo First Hospital, Ningbo, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Cao
authors.affiliation: Department of pathology, Affiliated Hospital, Guangdong Medical College, Zhanjiang, China.
authors.forename: Zhiliang
authors.initials: Z
authors.lastname: Jing
authors.affiliation: Department of pathology, Zhejiang University School of Medicine, Hangzhou, China.
authors.forename: Li
authors.initials: L
authors.lastname: Huang
authors.affiliation: Department of Respiratory and Critical Care Medicine, Affiliated Hospital, Institute of Respiratory Diseases, Guangdong Medical College, Zhanjiang, China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Lv
authors.affiliation: Department of Respiratory and Critical Care Medicine, Affiliated Hospital, Institute of Respiratory Diseases, Guangdong Medical College, Zhanjiang, China.
authors.forename: Xuanna
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Department of Respiratory and Critical Care Medicine, Affiliated Hospital, Institute of Respiratory Diseases, Guangdong Medical College, Zhanjiang, China.
authors.forename: Quanchao
authors.initials: Q
authors.lastname: Lv
authors.affiliation: Department of Respiratory and Critical Care Medicine, Affiliated Hospital, Institute of Respiratory Diseases, Guangdong Medical College, Zhanjiang, China.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Respiratory and Critical Care Medicine, Affiliated Hospital, Institute of Respiratory Diseases, Guangdong Medical College, Zhanjiang, China.
authors.forename: Dongming
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Respiratory and Critical Care Medicine, Affiliated Hospital, Institute of Respiratory Diseases, Guangdong Medical College, Zhanjiang, China. wubin621011@126.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Wu
authors.affiliation: Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital, Institute of Respiratory Diseases, Zhejiang University School of Medicine, Hangzhou, China. huahaoshen@163.com.
authors.forename: Huahao
authors.initials: H
authors.lastname: Shen
mesh_terms: D054392:Adipokines / Q000097:blood* / Q000276:immunology*; D056151:Airway Remodeling / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D000071451:Chitinase-3-Like Protein 1; D005260:Female; D005347:Fibroblasts / Q000276:immunology*; D006801:Humans; D037102:Lectins / Q000097:blood* / Q000276:immunology*; D008168:Lung / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000276:immunology*; D012008:Recurrence; D012720:Severity of Illness Index
chemical_list: D054392:Adipokines; D015415:Biomarkers; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D037102:Lectins
keywords: CHI3L1; Chronic obstructive pulmonary disease; Disease severity; Exacerbation; YKL-40