Persisting signs of disease activity at Magnetic Resonance Enterocolonography predict clinical relapse and disease progression in quiescent Crohn's disease

Introduction : Deep remission including clinical remission and tissue healing has been advocated as the therapeutic target in Crohn's disease. Yet, the definition of deep remission remains un- clear. The aim of this study was to assess the persisting lesions at mag- netic resonance enterocolonography (MREC) in clinically quies- cent Crohn's disease as well as their relapse predictive value. Methods : we performed a prospective monocentre cohort study. We included patients with clinical remission. At baseline, these pa- tients had blood tests, the measurement of fecal calprotectin and underwent a MREC. They were then followed up clinically for a minimum of 1 year. A relapse was defined by a HBI > 4 with an increase of at least 3 points. Correlations between clinical, demo- graphic, biological parameters and MREC signs were assessed as well as the time-to-relapse predictive value of the studied variables. Results : Twenty seven patients were recruited. Fourteen out of 27 had persisting disease activity at MREC. MREC signs only part- ly correlated with biomarkers. Ten out of 27 patients relapsed over a median follow up of 25 months. In univariate analysis, relative contrast enhancement of the most affected segment (HR : 2.56 ; P=0.046), ulcers (HR: 12.5; P=0.039), fistulas (HR: 14.1; P = 0.009) and target sign (HR : 3.63 ; P = 0.049) were associated with relapse. In multivariate analysis, fistula was the only one. Conclusions: Half of the patients with clinically quiescent Crohn's disease had persisting signs of disease activity at MREC. These signs predicted time-to-relapse. (Acta gastroenterol. belg., 2015, 78, 274-281).