Autoimmune hepatitis in children

Abstract

Autoimmune hepatitis (AIH) is a disease of unknown aetiology, in which a progressive destruction of the hepatic parenchyma occurs. This disease follows a chronic, but fluctuating course. AIH spontaneously progresses towards cirrhosis and liver failure, but often shows a relatively good response to immunosuppressive treatment¹. It is characterized by a female preponderance, marked hyper-gammaglobulinaemia, circulating autoantibodies, low levels of complement factor 4 and a high prevalence of HLA B8 and DR3 and DR4 haplotypes¹. Other autoimmune disorders are frequently found in patients with AIH as well as in first-degree relatives^1-3. These clinical and laboratory observations led to the hypothesis that AIH is a multifactorial disease. Autoimmune associated disorders are of B and T lymphocyte origin, and other anomalies of the immune system, such as low levels of circulating IgA, are not uncommon. Two types of AIH are currently recognized according to the nature of the autoantibody detected in children at the time of diagnosis. Patients with AIH type 1 display anti-smooth muscle antibodies (SMA) and/or anti-nuclear antibodies (ANA) in their sera. AIH type 2 is characterized by anti-liver kidney microsome (LKM1) and/or anti-liver cytosol type 1 antibodies (LCl)^2,3.