Incidence and prevalence of primary biliary cirrhosis, primary sclerosing cholangitis, and autoimmune hepatitis in a Norwegian population

Background: The relative frequencies of the autoimmune liver diseases primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), and autoimmune hepatitis (AIH) have not been studied. We therefore performed an epidemiologic investigation to describe the incidence and prevalence of the three diseases in a defined population. Methods: Patients with PBC, PSC, or AIH admitted to Aker University Hospital in Oslo were prospectively registered during the 10-year period 1986-95. This hospital serves a defined population of 130,000 inhabitants. The mean yearly incidence and the point prevalences at the end of each year were calculated. Results: During the 10-year period 21 patients with PBC, 17 with PSC, and 25 with AIH were diagnosed. The mean annual incidence per 100,000 was 1.6 for PBC, 1.3 for PSC, and 1.9 for AIH. The point prevalences per 100,000 on 31 December 1995 were 14.6, 8.5, and 16.9 for PBC, PSC, and AIH, respectively. Conclusions: The prevalences of PBC and AIH, are of the same order of magnitude and about twice as high as that of PSC. These epidemiologic data can be used to estimate the number of liver transplantations required due to autoimmune liver diseases.