Fecal calprotectin in predicting small bowel capsule endoscopy findings in pediatric patients with known Crohn’s disease

Fecal calprotectin (FC) has been proposed as a noninvasive surrogate marker of intestinal inflammation in inflammatory bowel disease. This study aimed to assess the capability of FC in predicting small bowel capsule endoscopy (SBCE) findings in pediatric patients with known Crohn’s disease (CD). We retrieved data of consecutive patients aged 2 to 17 years old with established CD who underwent SBCE from Janurary 2017 to April 2020 and had endoscopic remission on ileocolonoscopy. Sixty-eight patients were included in the analysis. There were 13 patients with a weighted pediatric CD activity index ≥ 12.5, 47 patients with FC ≥ 200 µg/g, and 45 patients with significant small bowel (SB) inflammation [Lewis score (LS) ≥ 135]. The LS correlated weakly with FC (R = 0.30, P < .05). The area under the curve of FC as a surrogate diagnostic test for LS ≥ 135 was 0.691, and the optimal FC cutoff values were 242 µg/g with the corresponding sensitivity and specificity of 78% and 65%, respectively. The area under the curve of FC for moderate-to-severe inflammatory activity in the SB was 0.718. In patients with FC level ≥ 670 µg/g, LS ≥ 790 was found in 33% (9/27) of patients, with the sensitivity and specificity of 69% and 67%, respectively. FC may be used to predict SB mucosal inflammation in pediatric patients with confirmed CD having endoscopic remission on ileocolonoscopy.