title: YKL-40 protein is a marker of asthma.
abstract: BACKGROUND
  Gaining asthma control is still a challenge in a large number of patients. It could be facilitated by using biomarkers indicating the grade of inflammation and correlating with clinical picture. Chitinases and chitinase-like proteins play a role in Th2-type inflammation. Thus, they may be useful in diagnosing and monitoring of asthma.
  
  
  OBJECTIVE
  The aim of the study was to investigate the relevance of YKL-40 as a good biomarker of asthma, its control, and severity.
  
  
  METHODS
  Level of YKL-40 was determined by means of immunoassay in sera of 59 asthmatics (39 women, 20 men, aged 23-76 years) and 29 healthy controls (18 women, 11 men, aged 20-80 years). Asthma severity and control were assessed according to GINA guidelines. Differences between groups were compared with the use of Mann-Whitney's U-test. Correlations between variables were assessed with Pearson's test.
  
  
  RESULTS
  Symptoms of asthma were found to be controlled in 12 (20%), partly controlled in 17 (29%), and uncontrolled in 30 (51%) patients. YKL-40 levels were significantly higher, on average, in asthmatics compared to control group (median levels: 125.3 U and 84.1 U, respectively, p < .001). YKL-40 correlated with the number of blood eosinophils (r = 0.376, p = 0.05). However, no relations have been found between YKL-40 level and asthma severity, control, or total serum IgE (r = -0.05, p = .05).
  
  
  CONCLUSIONS
  YKL-40 seems to be a good marker of asthma. However, its level may not correlate with clinical outcome.
authors: Department of Allergology, Medical University of Gdansk, Poland. specjalski@poczta.onet.pl
authors: Krzysztof
authors: K
authors: Specjalski
authors: Ewa
authors: E
authors: Jassem
mesh_terms: D054392:Adipokines / Q000097:blood*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000097:blood / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D000071451:Chitinase-3-Like Protein 1; D004802:Eosinophilia / Q000097:blood; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D037102:Lectins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric; D055815:Young Adult
chemical_list: D054392:Adipokines; D015415:Biomarkers; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D037102:Lectins; D007073:Immunoglobulin E