title: Segmental allergen challenge enhances chitinase activity and levels of CCL18 in mild atopic asthma.
abstract: BACKGROUND
  Allergic airway inflammation contributes to the airway remodelling that has been linked to increased obstruction and morbidity in asthma. However, the mechanisms by which allergens contribute to airway remodelling in humans are not fully established. CCL18, chitotriosidase (CHIT1) and YKL-40 are readily detectable in the lungs and contribute to remodelling in other fibrotic diseases, but their involvement in allergic asthma is unclear.
  
  
  OBJECTIVE
  We hypothesized that CCL18, YKL-40 and CHIT1 bioactivity are enhanced in allergic asthma subjects after segmental allergen challenge and are related to increased pro-fibrotic and Th2-associated mediators in the lungs.
  
  
  METHODS
  Levels of CCL18 and YKL-40 protein and chitotriosidase (CHIT1) bioactivity in bronchoalveolar lavage (BAL) fluid, as well as CCL18, YKL-40 and CHIT1 mRNA levels in BAL cells were evaluated in patients with asthma at baseline and 48 h after segmental allergen challenge. We also examined the correlation between CCL18 and YKL-40 levels and CHIT1 activity with the levels of other pro-fibrotic factors and chemokines previously shown to be up-regulated after allergen challenge.
  
  
  RESULTS
  Chitotriosidase activity and YKL-40 and CCL18 levels were elevated after segmental allergen challenge and these levels correlated with those of other pro-fibrotic factors, T cell chemokines, and inflammatory cells after allergen challenge. CCL18 and YKL-40 mRNA levels also increased in BAL cells after allergen challenge.
  
  
  CONCLUSIONS
  Our results suggest that CCL18 and YKL-40 levels and CHIT1 activity are enhanced in allergic airway inflammation and thus may contribute to airway remodelling in asthma.
authors: Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792-9988, USA.
authors: M L
authors: ML
authors: Gavala
authors: E A B
authors: EA
authors: Kelly
authors: S
authors: S
authors: Esnault
authors: S
authors: S
authors: Kukreja
authors: M D
authors: MD
authors: Evans
authors: P J
authors: PJ
authors: Bertics
authors: G L
authors: GL
authors: Chupp
authors: N N
authors: NN
authors: Jarjour
mesh_terms: D054392:Adipokines / Q000378:metabolism; D000328:Adult; D056151:Airway Remodeling; D000485:Allergens / Q000008:administration & dosage / Q000276:immunology*; D001249:Asthma / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D001985:Bronchial Provocation Tests; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology; D019742:Chemokines, CC / Q000378:metabolism*; D000071451:Chitinase-3-Like Protein 1; D002688:Chitinases / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism; D004789:Enzyme Activation; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D037102:Lectins / Q000378:metabolism; D008297:Male; D013997:Time Factors; D055815:Young Adult
chemical_list: D054392:Adipokines; D000485:Allergens; C111792:CCL18 protein, human; C084533:CHI3L1 protein, human; D019742:Chemokines, CC; D000071451:Chitinase-3-Like Protein 1; D016207:Cytokines; D018836:Inflammation Mediators; D037102:Lectins; D002688:Chitinases