Comparison of clinical features and liver histology in acute and chronic autoimmune hepatitis

Aim: We investigated the clinical and morphological features between acute and chronic autoimmune hepatitis (AIH) with or without acute exacerbation. Methods & Results: Serum total bilirubin on average was elevated to 12 mg/dL in acute AIH, alanine aminotransferase and aspartate aminotransferase peaked to more than 1000 U/L, and serum gamma-glutamyl transpeptidase was higher in the acute type compared with the chronic type without exacerbation. Serum immunoglobulin G was lowest in all other types of AIH. A liver biopsy showed interface or lobular hepatitis with lympho-plasmacytic infiltration, and rosette formations were frequently seen in acute AIH. There were morphological changes of central necrosis with plasmacytic infiltration and giant cell hepatitis. CK19-positive cholangiolar cells had proliferated in the periportal area with massive necrosis, and bile duct injuries were seen in acute AIH more frequently than in the chronic type. Conclusion: Laboratory data and liver histology in acute AIH differed from those of chronic AIH and were clarified for the diagnosis of acute AIH.