Transitions between variant forms of primary biliary cirrhosis during long-term follow-up.

BACKGROUND: Conditions exhibiting features of two different autoimmune liver diseases are designated overlap syndromes. Variant forms display some, but not all, characteristics of a distinct autoimmune liver disease. We describe transitions over time between variant forms of PBC, i.e. AMA-negative PBC, autoimmune hepatitis (AIH)-PBC overlap and autoimmune cholangitis (AIC) in a large cohort of PBC patients in Sweden. METHODS: We retrieved all patients with variant forms of PBC in six university hospitals in Sweden, covering 60% of the Swedish population. The diagnosis of PBC and its variants was based on laboratory findings and compatible histological features. The revised autoimmune hepatitis scoring system proposed by the International Autoimmune Hepatitis Group was used to establish the diagnosis of AIH. RESULTS: In a population of 800 patients with PBC, we identified 35 (5%) variant forms; 25 patients with AIH-PBC overlap, 8 with AIC and 2 with AMA-negative PBC at the time of our study. The initial diagnoses were PBC (3 patients), AIH (3), AIH-PBC overlap (16), AIC (8) and AMA-negative PBC with (1) or without (4) concomitant AIH. The median follow-up was 125 (41-360) months. Immunosuppression and ursodeoxycholic acid induced a complete or good regression of increased aminotransferases in about half of the patients who were given one or both of these treatments. CONCLUSIONS: Variant forms of PBC are seen in approximately 5% of PBC patients in Sweden. Transition between different forms may occur, emphasizing the value of repeat biopsies, but established overlapping AIH-PBC seems to be stable over time.

High prevalence of small duct primary sclerosing cholangitis among patients with overlapping autoimmune hepatitis and primary sclerosing cholangitis.

BACKGROUND: Overlap syndrome is a term used for overlapping features of autoimmune hepatitis and primary sclerosing cholangitis or primary biliary cirrhosis and for autoimmune cholangitis. We describe a high prevalence of small duct primary sclerosing cholangitis among patients with overlapping autoimmune hepatitis and primary sclerosing cholangitis. METHODS: We sought to retrieve all patients with overlap syndrome between primary sclerosing cholangitis and autoimmune hepatitis in six university hospitals in Sweden. The revised autoimmune hepatitis scoring system proposed by the International Autoimmune Hepatitis Group was used to establish the diagnosis autoimmune hepatitis. Endoscopic retrograde cholangiography and/or magnetic resonance cholangiography were used to separate the primary sclerosing cholangitis cases diagnosed through liver biopsy into small and large primary sclerosing cholangitis. A histological diagnosis compatible with both autoimmune hepatitis and primary sclerosing cholangitis was required for inclusion. RESULTS: 26 patients fulfilled our criteria for histological overlap of autoimmune hepatitis and primary sclerosing cholangitis, 7 (27%) of which had small duct primary sclerosing cholangitis. The reliability of the diagnosis small duct primary sclerosing cholangitis was supported by a very close similarity between small and large duct primary sclerosing cholangitis patients in clinical and laboratory data, and by a poor response to immunosuppressive therapy in the small duct primary sclerosing cholangitis patients. Patients with large duct overlap syndrome had a good response to immunosuppressive therapy. In both groups, our limited experience from ursodeoxycholic acid was largely poor. CONCLUSIONS: Small duct primary sclerosing cholangitis is prevalent in the overlap syndrome between autoimmune hepatitis and primary sclerosing cholangitis.