Intestinal Barrier healing is superior to transmural healing to prevent disease progession in clinical remittent patients with IBD

Background Achieving endoscopic remission is a key therapeutic goal in IBD that is associated with improved disease outcome. Transmural and intestinal barrier healing represent emerging targets, as they have similarily been associated with favourable disease behaviour. To date, no study has compared these novel endpoints and their impact on avoiding deleterious disease outcome. Methods Clinically remittent IBD patients underwent ileocolonoscopy with assessment of intestinal barrier function by endomicroscopy. Transmural healing was assessed by magnetic resonance imaging (MRI) or intestinal ultrasonography (IUS). Endoscopic and histologic disease activity were prospectively assessed along established scores. During subsequent follow-up (FU), patients were closely monitored for disease activity and major adverse outcomes (MAO): Disease flares, IBD-related hospitalization/surgery, initiation or escalation of systemic steroid, immunosuppressive or targeted advanced therapy. Results 80 patients (47 CD, 33 UC) were included. During a mean FU of 34 (CD) and 18 (UC) months, 72% of CD and 85% of UC patients experienced MAO. Intesinal barrier healing exhibited the highest accuracy for predicting MAO-free survival in UC and CD patients and outcompeted transmural healing for predicting the further disease course. Both, barrier healing and transmural healing showed higher diagnostic accuracy in forecasting the future course of disease when compared to endoscopic and histologic remission. Conclusion Intestinal barrier healing is superior to transmural healing to prevent disease progession in clinical remittent IBD patients while both barrier and transmural healing showed superiority over endoscopic and histologic remission. Hence, barrier and transmural healing are emerging endpoints potentially refining disease monitoring and outcome prediction.