[Autoimmune hepatitis: present knowledge].

Autoimmune hepatitis (AIH) is a rare and chronic disease which may lead to liver cirrhosis if not correctly treated. Its etiology is unknown, but some progresses have been obtained in the knowledge of damage pathogenesis, its immune mechanisms and genetic predisposition (female gender, presence of HLA DR3 and HLA DR4). It seems that such predisposition favours some agents (e.g. drugs or viruses) to trigger the pathological process. Patients present with variable, often few and unspecific symptoms. Diagnosis is made on the basis of anamnestic (absence of other causes, such as virus infections or alcohol abuse), serological (autoantibodies, high levels of aminotransferases, hypergammaglobulinemia), and histological data (piecemeal necrosis further to bridging necrosis, panlobular and multilobular necrosis); these data are processed by a scoring system which is helpful for the diagnostic definition. Therapy is founded in immunosuppressor drugs, mainly steroids and azathioprine, but a lot of other drugs have been studies for cases of recurrence and of intolerance to the standard treatment.