Background: Only a few studies have attempted to determined the prevalence of long-standing abnormal liver function and primary sclerosing cholangitis (PSC) in patients with Crohn's disease (CD). The aim of the study was to determine the prevalence of long-standing abnormal liver function test results and to describe the clinical, biochemical, and histologic findings in patients with large-duct classic PSC and small-duct PSC (that is, normal cholangiogram) in patients with CD during a 15-year period.
Methods: Patients with CD and long-standing abnormal liver function results were investigated individually with endoscopic retrograde cholangiography and liver biopsy.
Results: Of 262 consecutive patients with CD, 38 (15%) had long-standing increased alkaline phosphatase (ALP) values (mean, 1065 U/l; range, 321-4165 U/l). Of these, 10 patients were classified as having hepatic disease (4%), of which 9 had PSC and 1 had a non-specific reactive hepatitis. Of nine patients with PSC (3.4%), three were classified as having large-duct PSC; five, small-duct PSC; and one, unclassified. In patients with large-bowel CD (n = 102) the prevalence of PSC was 9%. Mean age at diagnosis of PSC was 35 years (22-46 years), and the female to male ratio, 7:2. All PSC patients had large-bowel involvement (P < 0.00015), and two of them developed colonic carcinoma of the large bowel (P < 0.01). All cases of small-duct PSC were stage 1, whereas large-duct PSC were stage 2-3. During the observation period (mean, 5.4 years) no PSC patients died.
Conclusions: The results of our study indicate that PSC is the major hepatic disease in patients with CD and long-standing abnormal liver function tests and is approximately as prevalent as in ulcerative colitis. Patients with PSC and CD may have a milder liver disease than patients with PSC and ulcerative colitis, perhaps because large-duct PSC is less common in patients with CD. Cholangiograms and liver biopsies are both needed to evaluate the extent of the disease.