A case of primary biliary cirrhosis and autoimmune hepatitis overlap showing acute presentation and transient seropositivity for immunoglobulin G and anti-nuclear antibody.

Autoimmune hepatitis (AIH) is generally regarded as a clinically and histologically "chronic" hepatitis. It often shows acute presentation like acute hepatitis without typical clinicopathological features of AIH, especially in a case of overlap with primary biliary cirrhosis (PBC). A 52-year-old man showed mild liver dysfunction for the first time at an annual medical check. Two months later, he showed jaundice, and laboratory tests revealed elevation of liver enzymes, hyperbilirubinemia and prolonged prothrombin time activity like acute liver failure. Anti-mitochondrial antibody was positive and other viral and autoimmune markers were negative. His liver function tests improved upon treatment with ursodeoxycholic acid and maximum intravenous glycyrrhizin (IVGL), but liver dysfunction was again exacerbated after the gradual reduction of IVGL. He showed transient elevation of immunoglobulin G (IgG) and anti-nuclear antibody (ANA) at only one point, and liver histology was compatible with PBC and AIH overlap syndrome. Corticosteroid was administered and his liver function tests returned to normal. It is important for the diagnosis of acute onset AIH to monitor IgG level and ANA titer, especially in patients without IgG and ANA elevations at first appearance.