Background: Noninvasive biomarkers of intestinal inflammation can reduce the number of endoscopies in children with inflammatory bowel disease (IBD). This study aimed to prospectively investigate the usefulness of fecal calprotectin (FCP) and fecal immunochemical test (FIT) in pediatric IBD.
Methods: Patients aged 6-17 years who underwent ileocolonoscopy for established or suspected IBD were eligible for this study. Fecal samples for FCP and FIT were collected before colonoscopy.
Results: A total of 251 samples were analyzed: 88 from ulcerative colitis (UC), 74 from Crohn's disease (CD), 75 from healthy controls (HC), and 14 from children with functional gastrointestinal disorders and normal colonoscopy (NC). At IBD diagnosis, both FCP and FIT were significantly higher in the newly diagnosed UC/CD group than in the HC/NC group (P < 0.001). The optimal cutoffs of FCP and FIT to predict IBD diagnosis were 217 mg/kg and 87 ng/mL, respectively. Patients without mucosal healing (MH) showed higher FCP and FIT than those with MH in both UC and CD (P < 0.001). The FCP increased exponentially as the endoscopic activity score increased. The optimal cutoff values of FCP and FIT for predicting MH were 161 mg/kg and 106 ng/mL for UC and 367 mg/kg and 57 ng/mL for CD, respectively. FCP showed better specificity than the FIT. Patients with CD and normal ileocolonoscopy had elevated FCP during active small intestinal inflammation.
Conclusions: Both FCP and FIT correlate well with endoscopic activity in pediatric patients with IBD. The FCP is a superior marker for predicting MH.
Keywords: Crohn’s disease; Fecal calprotectin; Fecal immunochemical test; Inflammatory bowel disease; Ulcerative colitis.
© 2022. Japanese Society of Gastroenterology.