Autoimmune liver diseases.

Autoimmune liver diseases are characterized histologically by a dense mononuclear cell infiltrate in the portal tract and serologically by high levels of transaminases and immunoglobulin G (IgG) and positive autoantibodies, in the absence of a known etiology. In pediatrics, there are three liver disorders in which liver damage is likely to arise from an autoimmune attack: autoimmune hepatitis (AIH); autoimmune sclerosing cholangitis (ASC); and de novo autoimmune hepatitis after liver transplantation. The exact pathogenesis of AIH is still unknown, but it is known that unidentified environmental factors, and occasionally drugs, might trigger disease in genetically-susceptible individuals. The clinical spectrum of disease is very wide, ranging from asymptomatic individual with abnormal liver function test to fulminant liver failure. The diagnosis is based on the combination of biochemical and histological parameters, and exclusion of other liver diseases. It is a relatively rare but devastating disease, which progresses rapidly unless immunosuppressive treatment is started promptly. Standard therapy consists of a combination of corticosteroids and azathioprine, which is efficacious in 80% of patients. Alternative therapies are increasingly being explored in patients who do not respond to the standard treatment and/or have intolerable side effects. The purpose of this review was to provide an overview of the current knowledge on pediatric autoimmune liver disease.