Autoimmune hepatitis

Autoimmune hepatitis is an idiopathic inflammation of the liver attributed to immune responses against self-antigens presumed to be of hepatocyte origin. It is typically a relapsing and remitting corticosteroid-responsive condition associated with hepatitic serum liver tests, elevated gammaglobulins, and positive immune serology. Histological features are not specific but often include expanded portal tracts with a lymphoplasmacytic infiltrate. Epidemiology: predominantly affects women, may occur throughout life, has some heritable component, and 60% of patients have other autoimmune diseases. Clinical features: many patients are asymptomatic and identified through investigation of abnormal serum liver tests. Presentation may be with anorexia, nausea, hepatic discomfort, and jaundice, but others may have nonspecific malaise or extrahepatic manifestations such as arthralgia, arthritis, or fever. Clinical signs vary greatly, ranging from none to jaundice and tender hepatomegaly to fulminant hepatic failure. One-third of patients present as cirrhotic. Diagnosis: characteristic laboratory findings include elevated serum transaminase activities, hypergammaglobulinaemia (as IgG), and circulating autoantibodies (e.g. antismooth muscle antibodies, anti-liver–kidney microsomal antibodies, and antinuclear antibodies). Diagnosis depends on the combination of clinical features and biochemical, immunological, and liver biopsy abnormalities, with exclusion of viral and other aetiologies. There may be overlap features with other autoimmune liver diseases (primary sclerosing cholangitis or primary biliary cholangitis). Treatment and prognosis: the condition tends to progress to hepatic fibrosis and cirrhosis. Most cases should be treated with an immunosuppressive regimen, typically prednisolone with azathioprine in the first instance, and most require long-term immunosuppression. Crude 10-year survival rate is 65% for those presenting with cirrhosis and greater than 95% for those presenting without. End-stage decompensated cirrhosis and acute nonresponsive autoimmune hepatitis with liver failure can be indications for liver transplantation.