Autoimmune hepatitis in a genetically susceptible patient: is it triggered by acute viral hepatitis A?

The pathogenic mechanisms for autoimmune hepatitis (AIH) are not completely known. Susceptibility to AIH is associated with the human leukocyte antigens (HLA) class II: DR3 and DR4. Nevertheless, AIH does not have a strong genetic predisposition, suggesting that other factors are involved. Perhaps the strongest evidence of a viral cause for AIH exists for hepatitis C virus. AIH has been reported to develop rarely after acute infection with hepatitis A virus. We report on a 55-year-old woman in whom AIH developed during the convalescence period of serologically proven acute viral hepatitis type A. HLA class II DRB1*0401, which was reported to be associated with AIH with a moderate coarse and late appearance in life, was found in this patient. Steroid therapy was followed by a complete clinical remission. Our case supports the possibility that acute hepatitis A may trigger the development of AIH in a genetically susceptible subject.