Assessment of Hepatic Fibrosis by Magnetic Resonance Elastography in Patients With Sclerosing Cholangitis

Abstract

Background and aims: PSC-IBD is reported to represent a distinct phenotype of IBD characterized by colitis, rectal sparing and backwash ileitis, but this has so far not been confirmed in large well-phenotyped cohorts. The aim of this study was to assess the IBD phenotype associated with PSC in a large Dutch PSC cohort using endoscopic and histopathological criteria. Methods: PSC cases were identified and ascertained, fulfilling well-established serological, histological and radiological criteria in 30 hospitals in The Netherlands. IBD location was recorded according to the Montreal classification. To assess the occurrence of backwash ileitis a subgroup analysis was performed in 40 cases and 80 ageand sex-matched IBD controls with at least one complete ileocolonoscopy including terminal ileum histology, reviewing 370 endoscopy and pathology reports written between 2001 and 2010. Results: 324 (64%) of a total of 506 PSC patients had coexistent IBD, mainly ulcerative colitis (UC, 72%). 147 (80%) of the PSC-UC patients had a pancolitis, 28 (15%) a left sided colitis and eight (4%) a proctitis. Sixty (95%) PSC-Crohn's disease (CD) patients had an (ileo)colitis and three ileitis only (5%). In the subgroup analysis of 40 PSC-IBD patients twenty-seven (68%) PSC-UC patients were identified, as well as twelve (30%) PSC-CD patients and one (2%) PSC-undetermined IBD patient. Twenty-five (93%) PSC-UC patients had a pancolitis, compared to thirty-three (61%) matched UC patients (p = 0.034). Left sided colitis was seen in seventeen (32%) UC controls and in none of the PSC-UC patients (p = 0.001). Backwash ileitis was seen in only one (4%) PSC-UC patient and in none of the UC controls. Conclusion: PSC-IBD represents a distinct IBD phenotype. The majority of Dutch PSC-UC patients have a pancolitis. In case of PSC-CD, colonic inflammation is involved in 95% of patients. Backwash ileitis is not a prominent finding in Dutch PSC-UC cases.