Clinical and prognostic implications of acute onset of Autoimmune Hepatitis: An Italian multicentre study.

Autoimmune Hepatitis (AIH) can present under clinical profile as acute hepatitis of unexplained cause. We analyzed clinical, therapeutical and prognostic implications of AIH presenting as acute hepatitis in a cohort of patients admitted to 3 referral Centres in Italy. AIH onset was considered acute when transaminases were higher than 10 times the normal limit and/or bilirubin higher than 5 mg/ml (irrespectively from the histology, available only in 62% of cases). Among 479 patients diagnosed as AIH, 202 (43%) met the criteria of acute onset. This former group of patients on the basis of the histology has been subdivided in the "genuine" acute onset (83 pts) and acute "on chronic" onset (45 pts) At onset, clinical acute AIH showed significantly higher ALT, bilirubin and INR levels (p < 0.001 for all), lower albumin values (p = 0.001), similar IgG levels; Response to treatment was similar between the two groups. The progression to liver cirrhosis or its complications was significantly less frequent in acute onset AIH (13% vs. 22%, p = 0.02). The "genuine" acute patients showed a higher albumin serum levels (40 vs. 36, p = 0.001), lower INR levels (1.12 vs. 1.26, p = 0.002) and less tendency to the progression of liver disease (7% vs. 12%, p = NS) with respect to acute "on chronic" onset patients. Clinical acute hepatitis represents a common presentation of AIH, responds to standard immunosuppression regimen and would seem to be correlated with a better long-term prognosis.