Wireless capsule endoscopy and faecal biomarkers in small bowel Crohn's disease patients: Role in assessing clinical remissions and predicting future relapses

Abstract

Background: Conventional parameters, including Crohn's Disease Activity Index (CDAl) and colonoscopy are limited in assessing small bowel Crohn's disease (CD) remission. Recent studies suggest that CD patients in clinical but not endoscopic remission have worse long-term outcomes. Capsule endoscopy (CE) is the most sensitive test to diagnose small bowel CD, however, its role in assessing remission remains undetermined.

Aims and methods: The alms of this study were to report CE findings in small bowel CD patients In clinical remission and compare these findings and faecal biomarker levels with standard clinical assessment tools (CDAl and CAP} in determining remission. Subsequently we assessed whether CE and the faecal biomarkers, calprotectin and S100A12, offered prognostic information about future CD relapses. 44 adult small bowel CD patients in clinical remission (CDAl <150) were prospectively enrolled and followed for 12 months. CE studies were reported using a Capsule Endoscopy Scoring Index (CESI). CDAl and CAP were measured at baseline and at 3 monthly intervals. Faecal calprotectin and S100A121evels were obtained at baseline.

Results: As assessed by CESI, 61% of patients in clinical remission had persistent inflammation distributed In the small bowel. Faecal calprotectln and S100A12 levels at baseline were elevated in 52% and 36% of patients, respectively. Calprotectin levels were normal in all patients without inflammation and elevated In all those with moderate-severe inflammation. CESI and baseline calprotectin and S100A12 levels were significantly correlated, while there was no correlation between CESI and either CDAI or CAP. All patients who had a clinical flare during 12 months followup, had mucosal inflammation at baseline CE and 75% had elevated baseline calprotectin levels. Interestingly, 63% of patients who had CE evidence of mucosal inflammation remained in clinical remission during the 12-month followup period.

Conclusion: In conclusion, in small bowel CD patients assessed in clinical remission, a significant proportion have ongoing mucosal inflammation on CE. Mucosal Inflammation significantly correlates with faecal calprotectin and S100A12 levels. However, only a minority of these patients develop clinical relapse at least In the medium term. These findings may have important clinical and therapeutic implications in the way small bowel CD is managed in the future.