New-onset autoimmune hepatitis in young patients with preexisting liver disease.

Autoimmune hepatitis (AIH) is thought to be a primary liver disease, occurring in the absence of any known etiology. We present three unusual cases of new-onset AIH in young female patients with longstanding preexisting liver disease (Alagille's syndrome, cystic fibrosis liver disease and sickle cell hepatopathy). All patients developed an insidious onset of abdominal pain, fatigue, jaundice and hepatitis after many years of their primary diagnosis and had negative serology for hepatitis A, B, C, cytomegalovirus and Epstein-Barr virus. The occurrence of AIH in these patients may be due to a complex interaction between the underlying liver disease, chronic medication use and genetic predisposition resulting in altered immunoregulatory mechanisms.