Limitation of the simplified scoring system for the diagnosis of autoimmune Hepatitis with acute onset.

Autoimmune Hepatitis (AIH) is a chronic inflammatory liver disease of unknown aetiology characterized by the presence of autoantibodies, hypergammaglobulinaemia with specific IgG increase and interface hepatitis on liver histology. The clinical course of AIH is classically characterized by fluctuating periods of decreased or increased disease activity and therefore its clinical spectrum is variable ranging from no symptoms to severe acute hepatitis and even fulminant hepatic failure. Acute presentation may not differ from acute hepatitis of other causes and diagnosis can be difficult. We describe our experience on diagnostic performance of the two AIH scoring systems in acute onset of AIH and found that revised version of the original criteria (1999) achieves the diagnosis in about 30% of patients who presented with normal IgG serum levels and lower frequency of autoantibody positivity in whom the simplified score did not allow the diagnosis.