Autoimmune hepatitis from the paediatric perspective.

Autoimmune hepatitis (AIH) is an important entity within the broad spectrum of autoimmune hepatobiliary disease comprised of AIH, primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). Since the 1960s, AIH has been investigated with extensive clinical research aimed at effective therapeutic intervention. It was one of the first liver diseases where treatment was demonstrated to prolong survival. AIH occurs in children, as well as in adults. Its clinical manifestations in children may differ from classic adult AIH. These differences have elucidated certain aspects of AIH and hepatobiliary disease in general. There are two major patterns of AIH: type 1, with anti-smooth muscle antibodies and type 2, with anti-liver/kidney microsomal antibodies. The second type of AIH was first identified in children and is more common in younger patients. AIH often presents as acute disease in children and also in adults: the nomenclature has dropped the allusion to chronicity. Some children who have sclerosing cholangitis present with clinical disease closely resembling AIH; this AIH-like PSC, termed autoimmune sclerosing cholangitis (ASC), is also found in adults. Children with AIH may have identifiable monogenic disorders of immune regulation such as autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). Like adults with AIH, children with AIH usually respond very favourably to immunosuppressive treatment with corticosteroids ± azathioprine. True cures seem to be rare, although many children achieve a stable remission. Nonetheless children with AIH may develop cirrhosis and some require liver transplantation. Early diagnosis and improved treatment strategies may further improve the outlook for children with AIH.