Role of capsule endoscopy and fecal biomarkers in small-bowel Crohn's disease to assess remission and predict relapse

Background and Aims: Capsule endoscopy (CE) is themost sensitive test to diagnose small-bowel Crohn's disease (CD). Conventional parameters poorly assess CD remission, and although fecal biomarkers assess colonic activity, their role in assessing remission is uncertain. We report CE findings in small-bowel CD patients in clinical remission compared with fecal biomarkers and standard clinical tools to determine mucosal remission and predict relapses. Methods: Forty-three adult small-bowel CD patients in clinical remission (Crohn's Disease Activity Index [CDAI] <150) were prospectively enrolled at 4 academic centers and followed clinically for 12 months. Baseline CE studies were scored using the Capsule Endoscopy Scoring Index (CESI or Lewis score). Baseline and endpoint fecal biomarkers were assayed. Results: CE findings were normal in 17 patients (40%), mild inflammation in 19 (44%), and moderate to severe inflammation in 7 (16%). Of the 26 patients (60%) with mucosal inflammation on CE, 85% had elevated baseline fecal calprotectin and 77% elevated lactoferrin level. Calprotectin and lactoferrin were normal in all patients without inflammation and elevated in all with moderate to severe inflammation. CESI correlated significantly with calprotectin, lactoferrin, and S100A12 levels but not either CDAI or C-reactive protein. During follow-up, 14% of patients exhibited a clinical flare; all had mucosal inflammation at CE and 83% had elevated baseline calprotectin and lactoferrin levels. Conclusions: In small-bowel CD patients in clinical remission, many had ongoing mucosal inflammation assessed by CE and fecal biomarkers. Only some developed a clinical flare during medium-term follow-up. These findings suggest CE and fecal biomarkers are useful in monitoring small-bowel CD progress.