Immunopathogenetic and therapeutic aspects of autoimmune hepatitis

Autoimmune hepatitis is a chronic, progressive liver disease that responds well to immunosuppressive therapy, but has a poor prognosis if untreated. Possible triggering factors include viruses, other autoimmune disorders and drugs. The molecular mechanisms contributing to the pathogenesis include: reactions of autoantibodies against their corresponding autoantigens; aberrant expression of histocompatibility antigen class I and II molecules, cell adhesion molecules and cytokines; increased oxidative stress; and the occurrence of angiogenesis. The prevalence of the disease is highest in Caucasians, Europeans and women. The natural history of autoimmune hepatitis shows a poor prognosis, with frequent progression to cirrhosis and hepatic insufficiency in untreated patients. The occurrence of hepatocellular carcinoma is rare and is found only in long-standing cirrhosis. Corticosteroids as monotherapy or in combination with azathioprine are the treatments of choice; different therapeutic schedules and particularities of treatment for pregnant women and children have been established. To avoid treatment-associated adverse effects, alternative therapies have been proposed, including ciclosporin, budesonide, tacrolimus, mycophenolate mofetil, ursodeoxycholic acid, methotrexate, cyclophosphamide, mercaptopurine and free radical scavengers. Liver transplantation is indicated for patients refractory to or intolerant of immunosuppressive therapy.