Changes in endoscopic activity and classification of lesions with panenteric capsule endoscopy in patients treated for Crohn's disease - a prospective blinded comparison with ileocolonoscopy, faecal calprotectin and C-reactive protein.

Background and aims: Panenteric capsule endoscopy (PCE) is a minimally invasive modality that may replace ileocolonoscopy (IC) in selected patients with Crohn's disease (CD). This study aimed to evaluate the dynamics of repeated assessment with PCE in patients receiving medical treatment for ileocolonic CD.

Methods: This prospective, blinded, multicentre study included patients with endoscopically active CD. Patients were scheduled for IC, PCE, faecal calprotectin and C-reactive protein before and 12 weeks after treatment with corticosteroids or biological therapy. The endoscopic disease activity was assessed with the Simple Endoscopic Score for Crohn's Disease (SES-CD).

Results: 31 patients entered the study, and PCE visualized 148 (95.5%) and 128 (82.6%) ileocolonic bowel segments before and after medical treatment, respectively. The median SES-CD decreased from 14 (IQR 8-17) to 5 (IQR 0-14) (P < 0.001) and 14 (IQR 10-17) to 6 (IQR 3-12) (P < 0.001) with IC and PCE, respectively. The repeated measurement correlation between PCE and IC was very strong (r = 0.77, P < 0.001), strong compared to faecal calprotectin (r = 0.42, P = 0.003) and moderate compared to C-reactive protein (r = 0.36, P = 0.005). The mean score for ulcer size, ulcerated surface and affected surface was equal to that of IC before and after treatment. PCE had a sensitivity and specificity of 80.6% (CI 62.5-92.5) and 93.8% (CI 79.2-99.2) for ulcer healing compared to IC.

Conclusion: PCE is responsive in patients treated for CD and may serve as a minimally invasive alternative to IC in selected patients.