Fecal immunochemical test versus fecal calprotectin for prediction of mucosal healing in Crohn's Disease

Background: Mucosal healing (MH) has been proposed as a treatment goal of inflammatory bowel disease patients. We reported recently that not only fecal calprotectin (Fcal) but also the fecal immunochemical test (FIT) can predict MH in ulcerative colitis. However, the predictive power of the fecal markers for MH in Crohn's disease (CD), particularly with small bowel lesions, has not been reported in detail. The aim of this study was to evaluate the predictability of FIT versus Fcal for MH in CD. Methods: Consecutive CD patients underwent colonoscopy or balloon-assisted enteroscopy according to the disease location. FIT and Fcal were examined using stool samples collected the day before endoscopy. Results: Seventy-one CD patients were analyzed, of whom 42 (59%) underwent balloon-assisted enteroscopy because of the presence of affected lesions in the small intestine. Both the Fcal and the FIT results were significantly correlated with endoscopic activity (r 0.67 and 0.54, respectively). However, the FIT results did not correlate with the activity in patients with small bowel lesions alone, whereas Fcal did (r 0.42 versus 0.78). Fcal predicted MH in CD with 87% sensitivity and 71% specificity, whereas the values for FIT were 96% and 48%, respectively. The specificity for MH among patients with small bowel lesions alone was low for FIT (40%) compared with Fcal (80%). Conclusions: Both FIT and Fcal were correlated with the mucosal status of CD. However, the specificity of FIT was not satisfactory, particularly for small bowel lesions.