Background and study aims: The aim of the study was to assess the usefulness of serum concentrations of YKL-40/ CHI3L1 (a 40-kilodalton glycoprotein also referred to as chitinase 3 like- 1 - CHI3L1) and PIIINP (N-terminal propeptide of type III procollagen), markers of fibrosis, in the monitoring of inflammatory processes and fibrosis in children with inflammatory bowel disease (IBD).
Patients and methods: In 60 patients (41 with Crohn's disease (CD), 19 with ulcerative colitis (UC)) concentrations of investigated parameters were measured at baseline (day 0), after 3 and after 6-8 weeks of pharmacological treatment.
Results: PIIINP concentrations were significantly higher in CD patients compared to UC (baseline results: median concentrations 1013.73 vs 78.30 ng/mL; P = 0.06 for the Kruskall-Wallis test; results at 6-8 weeks: 1076.48 vs 53.10 ng/mL, P = 0.01). Fibrosis was clearly present in patients with CD and its severity increased (reflected by both YKL-40/ CHI3L1 and PIIINP concentrations) in 6-8 weeks of follow up, regardless of the treatment used during that time. In patients with UC the levels of YKL-40/CHI3L1 and PIIINP were lower at baseline and further decreased after 6-8 weeks (median concentrations were respectively: 39.5 ng/mL vs 24.7 ng/mL and 78.3 ng/mL vs 53.1 ng/mL).
Conclusion: Fibrosis was more severe in CD than in UC patients. The marker that more accurately reflected these differences was PIIINP.
Keywords: Crohn’s disease; PIIINP; YKL-40/CHI3L1; ulcerative colitis.