title: YKL-40 in induced sputum after allergen bronchial provocation in atopic asthma.
abstract: BACKGROUND
  Serum chitinase-like proteins such as YKL-40 in asthmatic patients are known to positively correlate with disease severity but controversy remains regarding their role. The allergen bronchial provocation test (ABPT) can induce allergic airway inflammation in individuals with atopic asthma.
  
  
  OBJECTIVE
  To evaluate the induction and kinetics of YKL-40 during allergen-induced airway inflammation in atopic asthmatics.
  
  
  METHODS
  Thirteen patients were enrolled from May to November 2008. They all underwent ABPT with Dermatophagoides farinae crude extract. Induced sputums (IS) and serum were collected 3 times: 7 days before ABPT (baseline), 7 hours after ABPT, and 24 hours after ABPT. We examined the cytology of induced sputum (IS) and measured levels of YKL-40, interleukin (IL) 4, IL-5, IL-13, IL-33, tumor necrosis factor (TNF) alpha, and eosinophilic cationic protein (ECP) in IS and/or serum.
  
  
  RESULTS
  Following ABPT, total inflammatory cells, eosinophils, and neutrophils increased in a time-dependent manner in IS. YKL-40 levels were increased in IS but not in serum at 7 or 24 hours after ABPT (P=.011 and P=.006, respectively). Similarly to YKL-40, IL-5 and ECP levels were also increased in IS at 7 and 24 hours after ABPT (P=.011 for IL-5 and P=.006 for ECP). Overall, YKL-40 levels were well correlated with ECP levels in IS (p=0.576, P<.001).
  
  
  CONCLUSIONS
  YKL-40 levels increased immediately in IS but not in the serum of atopic asthmatics. The correlation between YKL-40 levels and ECP in IS suggests that YKL-40 may play a pathophysiologic role in human atopic asthma.
authors: Division of Allergy and Immunology, Department of Internal Medicine, Institute of Allergy, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors: J H
authors: JH
authors: Lee
authors: K H
authors: KH
authors: Park
authors: J W
authors: JW
authors: Park
authors: C S
authors: CS
authors: Hong
mesh_terms: D054392:Adipokines / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D000293:Adolescent; D000485:Allergens / Q000276:immunology; D001249:Asthma / Q000276:immunology / Q000378:metabolism*; D001985:Bronchial Provocation Tests; D000071451:Chitinase-3-Like Protein 1; D004797:Enzyme-Linked Immunosorbent Assay; D047150:Eosinophil Cationic Protein / Q000032:analysis / Q000276:immunology / Q000378:metabolism; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology / Q000378:metabolism*; D037102:Lectins / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D008297:Male; D013183:Sputum / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D055815:Young Adult
chemical_list: D054392:Adipokines; D000485:Allergens; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D037102:Lectins; D047150:Eosinophil Cationic Protein