Fecal calprotectin predicts endoscopic activity and mucosal healing of small bowel Crohn's disease evaluated by double-balloon endoscopy.

Abstract

Fecal calprotectin (FC) levels can reflect the level of intestinal inflammation. Crohn's disease (CD), which affects the small bowel, has not been linked to FC levels. We determined if FC levels and endoscopic activity were related by performing double-balloon endoscopy (DBE). Herein, patients with small bowel CD diagnosed by DBE between January 2020 and January 2022 were prospectively observed. Feces and blood samples of patients were collected before performing DBE and checked for the levels of FC and serological biomarkers. The endoscopic activity and mucosal healing (MH) were evaluated using the partial simple endoscopic score (pSES-CD). In all 254 CD patients, FC levels were correlated with pSES-CD (r = 0.775, P < 0.001). Even in patients with isolated small bowel CD, FC levels were strongly correlated with pSES-CD (r = 0.753, P < 0.001). In all patients, FC as an endoscopic remission indicator was found to have an area under the curve (AUC) of 0.872, with a cut-off value of 156.09 µg/g. In patients with isolated small bowel CD, FC yielded a high AUC of 0.865 for predicting endoscopic remission, with a cut-off value of 211.48 µg/g, sensitivity of 73.95%, and specificity of 91.30%. FC was optimally cut-off at 76.99 µg/g to predict MH in accordance with the AUC of 0.877. Using DBE findings, FC was found to be significantly correlated with pSES-CD. Even in isolated small bowel CD, FC may be a more reliable marker of accurately predicting endoscopic remission and MH.