DOP23 The role of histology for the prediction of clinical relapse in Crohn’s Disease: A substudy of the STORI cohort

Abstract

Abstract Background Deep remission has become the target in the management of Crohn’s disease (CD). The role of histology in the management of CD has not yet been established. The aim of this work was to study the impact of histological inflammation on the risk of clinical relapse in patients with CD in clinical and endoscopic remission and to study the correlation between histology and endoscopic scores and biomarkers. Methods All patients included in STORI (1) were eligible for inclusion. Fecal calproptectin and colonoscopy with CDEIS calculation were performed at inclusion. Two biopsies, taken either from the most inflammed macroscopic area or from an area with previous inflammation in case of mucosal healing (MH) were prospectively performed. MH was defined by the absence of ulcers. Different histological scores were calculated by 2 independent pathologists: Robart, Geboes, modified Geboes, Nancy, and DCA-IBD scores. Histological remission was defined by Nancy=0 ; Geboes ≤2 ; modified Geboes of grade 0 ; Robarts ≤3, IBD-DCA of C≤1 and A=0. Clinical relapse was prospectively evaluated in the STORI trial as CDAI>250 or CDAI between 150 and 250 with an increase of 70 points during 2 successive weeks compared to the inclusion visit. (1) Louis E et al .Gastroenterology 2012 Results Eighty biopsies (22 ileal and 58 colonic) were available from 76/115 patients included in STORI. Among the 45 patients with MH, 30 had colonic biopsies, 11 had ileal biopsies and 4 had biopsies in both locations. Among colonic biopsies 68% had histological remission according to Nancy and modified Geboes scores, 65% according to DCA-IBD and Geboes scores and 71% according to Robarts score. Among ileal biopsies 53% had histological remission according to Nancy score, 47% according to Modified Geboes, Geboes and DCA-IBD scores, and 67% according to the Robarts score. Thirty-five patients (46%) experienced a clinical relapse during the follow-up including 16/45 (36%) and 19/31 (61%) in the group with MH and without MH respectively. Histological characteristics and histological scores were not predictive of clinical relapse. In the total cohort (n=76), the CDEIS score was correlated to Nancy (p<0,001, r=0,43), Geboes (p<0,001, r=0,47) and Robarts (p<0,001, r=0,45) scores. Fecal calprotectin was correlated to Nancy (p<0,001, r=0,48), Geboes (p<0,001, r=0,45) and Robarts (p<0,001, r=0,46) scores. The histological scores of Nancy, Robarts and Geboes were highly correlated (p<0,0001 ; r > 0,9). Conclusion Although correlated with endoscopy and biomarkers, histology was not predictive of clinical relapse in CD patients in clinical and endoscopic remission. These findings do not support the use of histology to predict clinical relapse in CD in clinical practice.