title: Serum YKL-40 concentrations in patients with early rheumatoid arthritis: relation to joint destruction.
abstract: OBJECTIVE
  YKL-40 is a secretory glycoprotein of chondrocytes, synovial cells, macrophages, and neutrophils. The aims were to determine serum YKL-40 in patients with early rheumatoid arthritis (RA) and seek associations with early joint erosions.
  
  
  METHODS
  YKL-40 was measured by ELISA in serum samples collected every three month for 36 months from patients with early RA. The patients were treated with DMARDs and some were allocated to additional prednisolone.
  
  
  RESULTS
  Serum YKL-40 was higher in RA patients compared with controls (98 vs. 42 microg/l, p<0.001). The mean serum YKL-40 during the study correlated with the progression in Larsen score (Pearson's test: p=0.004). Patients with a persistently high serum YKL-40 had larger progression in Larsen score compared with patients with normal serum YKL-40 (median progression: 7 vs. 0, p=0.003).
  
  
  CONCLUSIONS
  These data suggest that elevated serum YKL-40 is related to progression in joint destruction in early RA patients.
authors.affiliation: Department of Rheumatology, Hvidovre Hospital, University of Copenhagen, Denmark. julia.johansen@post3.tele.dk
authors.forename: J S
authors.initials: JS
authors.lastname: Johansen
authors.forename: J R
authors.initials: JR
authors.lastname: Kirwan
authors.forename: P A
authors.initials: PA
authors.lastname: Price
authors.forename: M
authors.initials: M
authors.lastname: Sharif
mesh_terms: D054392:Adipokines; D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000473:pathology*; D015415:Biomarkers / Q000097:blood*; D000071451:Chitinase-3-Like Protein 1; D018450:Disease Progression; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006133:Growth Substances / Q000097:blood*; D006801:Humans; D007596:Joints / Q000473:pathology; D037102:Lectins; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index
chemical_list: D054392:Adipokines; D015415:Biomarkers; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D006133:Growth Substances; D037102:Lectins