Background: Studies evaluating the correlation between endoscopic disease activity and noninvasive markers are scarce in inflammatory bowel disease (IBD).
Aim: The aim of this study is to evaluate the accuracy of the fecal calprotectin (FC) assay as a marker of disease activity of IBD, as determined by an extensive endoscopic scoring system.
Methods: Thirty-five children and adolescents with IBD [17 with ulcerative colitis (UC) and 18 with Crohn's disease (CD)] and 28 healthy volunteers were enrolled. FC levels were determined by ELISA. The sum of Matts' score for UC and the simple endoscopic score for Crohn's disease (SES-CD) were used. The ileal lesions were evaluated by ultrasonography.
Results: In UC patients, there was a strong correlation between FC levels and the sum of Matts' score (r=0.838, p<0.01). FC levels were significantly elevated in endoscopically active patients (median 1,562.5 μg/g) as compared to patients in endoscopic remission (median 38.9 μg/g) or healthy controls (median 19.9 μg/g). In CD patients, there was a strong correlation between FC levels and the SES-CD score (r=0.760, p<0.01). The FC levels were significantly higher in endoscopically active patients (median 2,037.5 μg/g) than in endoscopically inactive patients (median 172.5 μg/g) or healthy controls (median 19.9 μg/g), respectively. The FC levels of patients with ileal wall thickening (median 2,225.0 μg/g) were significantly higher than healthy controls (median 19.9 μg/g) and patients lacking ileal wall thickening (median 17.5 μg/g), respectively.
Conclusions: The FC assay is a useful marker for the detection of mucosal inflammation in pediatric IBD patients.