Primary sclerosing cholangitis in the Swiss Inflammatory Bowel Disease Cohort Study: prevalence, risk factors, and long-term follow-up.

BACKGROUND AND AIM: Primary sclerosing cholangitis (PSC) represents the most common hepatobiliary extraintestinal manifestation of inflammatory bowel disease (IBD). We aimed to assess the prevalence of PSC in the Swiss Inflammatory Bowel Disease Cohort Study, to identify associated risk factors, and to describe the long-term evolution.

PATIENTS AND METHODS: Data of patients enrolled into the Swiss Inflammatory Bowel Disease Cohort Study were analyzed. Logistic regression modeling was performed to identify risk factors for PSC.

RESULTS: Among 2744 patients [1188 ulcerative colitis (UC); 1556 Crohn's disease (CD)], 57 had PSC (48 UC-PSC, nine CD-PSC). The prevalence of PSC was higher in UC compared with CD (4.04 vs. 0.58%, P<0.001). We identified the following significant independent risk factors for PSC in patients with UC: male sex [odds ratio (OR) 2.771, P=0.022], pancolitis (OR 2.855, P=0.011), nonsmoker at diagnosis (OR 9.253, P=0.030), and a history of appendicectomy (OR 4.114, P=0.019). During a median follow-up time of 74.8 months, four (7.0%) of PSC patients developed cholangiocarcinoma, six (10.5%) underwent liver transplantation, and five (8.8%) died. Survival of IBD-PSC patients was significantly worse compared with IBD patients without PSC (P=0.001). UC-PSC patients developed significantly more frequently colorectal cancer compared with UC patients without PSC (2/48 vs. 9/1440, P=0.017).

CONCLUSION: Approximately 4% of UC patients and 0.6% of CD patients had PSC. Male sex, pancolitis, nonsmoker status, and a history of appendicectomy were significantly associated with PSC. PSC is associated with considerable morbidity and mortality in the long term.