Serum YKL-40, a potential new marker of disease activity in patients with inflammatory bowel disease

Scand J Gastroenterol. 2003 Jun;38(6):599-605. doi: 10.1080/00365520310000537.


Background: YKL-40 is secreted by macrophages and neutrophils and is a growth factor for vascular endothelial cells and fibroblasts. Elevated serum concentrations of YKL-40 are found in patients with diseases characterized by inflammation or ongoing fibrosis. The aim of this study was to seek association between serum YKL-40 in patients with ulcerative colitis (UC) and Crohn disease (CD) and clinical disease activity.

Methods: One-hundred-and-sixty-four patients with UC and 173 patients with CD were studied. The Simple Clinical Colitis Activity Index (SCCAI) and the Harvey-Bradshaw (H-B) score were used to assess disease activity. Serum YKL-40 (determined by ELISA) was related to C-reactive protein (CRP) and disease activity.

Results: In patients with UC, the median serum YKL-40 rose with increasing disease activity, and patients with severe active disease had higher serum YKL-40 (median 59 microg/L (95% CI: 26-258 microg/L), P < 0.001) than patients with inactive UC (33 microg/L (19-163)) and age-matched controls (43 microg/L (20-124)). Patients with severe active CD had higher serum YKL-40 (59 microg/L (21-654), P < 0.001) than age-matched controls, but not higher than inactive CD patients (43 microg/L (17-306)). Serum YKL-40 was elevated in 41% of the patients with severe UC, in 10% with inactive UC, in 46% with severe CD and in 30% with inactive CD. Serum YKL-40 correlated with SCCAI in UC patients but not with H-B score in CD patients. In both patient groups, low correlations were found between serum YKL-40 and CRP, albumin and leucocytes.

Conclusions: Serum YKL-40 is elevated in patients with active IBD and may be complementary to inflammatory markers and clinical characteristics in the assessment of disease activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipokines
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Autoantigens / blood*
  • Biomarkers / blood*
  • C-Reactive Protein / analysis
  • C-Reactive Protein / biosynthesis*
  • C-Reactive Protein / immunology
  • Chitinase-3-Like Protein 1
  • Female
  • Glycoproteins / biosynthesis*
  • Glycoproteins / blood
  • Glycoproteins / immunology
  • Humans
  • Inflammatory Bowel Diseases / blood
  • Inflammatory Bowel Diseases / immunology*
  • Lectins
  • Male
  • Middle Aged
  • Severity of Illness Index


  • Adipokines
  • Autoantigens
  • Biomarkers
  • CHI3L1 protein, human
  • Chitinase-3-Like Protein 1
  • Glycoproteins
  • Lectins
  • C-Reactive Protein