Q J Med 2004; 97: 407-412
QJM vol. 97 no. 7 © Association of Physicians 2004; all rights reserved.
Type 1 autoimmune hepatitis: patterns of clinical presentation and differential diagnosis of the ‘acute’ type
From the 1Dipartimento di Medicina Interna, Cardioangiologia, Epatologia and 2Dipartimento di Malattie dell’Apparato Digerente, del Metabolismo, delle Malattie Infettive, Alma Mater Studiorum, Università di Bologna, Policlinico S. Orsola-Malpighi, Bologna, Italy
Received 17 November 2003 and in revised form 16 March 2004
Background: Autoimmune hepatitis (AIH) has three different presentations: chronic, acute and asymptomatic.
Aim: To evaluate AIH presentation in Italian patients and investigate criteria that differentiate between acute-type AIH and acute viral hepatitis.
Design: Prospective observational study.
Methods: Eighty-six consecutive patients with type 1 AIH and 41 with acute viral hepatitis (controls) were studied. ‘Acute’ AIH was defined as recent-onset (<30 days) symptoms (jaundice and/or fatigue and/or fever) with marked alterations in serum liver tests; the ‘asymptomatic’ pattern as the occasional detection of liver abnormalities, and the ‘chronic’ pattern as the presence of signs and/or symptoms of long-lasting liver disease.
Results: Of 86 AIH patients, 59 (68%) presented with the chronic pattern, 22 (26%) with the acute pattern, and 5 (6%) were asymptomatic. ‘Acute’ patients had higher AST, ALT and bilirubin serum levels (p < 0.0001). No differences were detected with respect to age and serum levels of alkaline phosphatase, 
-GT, albumin or -globulin. All three groups had similar prevalences of moderate/severe (vs. mild) histological findings and liver cirrhosis. When compared with controls with acute viral hepatitis, ‘acute’ AIH patients were more often female (82% vs. 24%, p < 0.0001) and had higher serum -globulin levels (26.9 vs. 13.4 g/l, p < 0.0001) and AST/ALT ratio (1.20 vs. 0.61, p < 0.0001).
Discussion: Although in Italy type 1 AIH patients usually present with a chronic pattern, some 25% have an acute presentation resembling that of viral hepatitis. ‘Acute’ AIH and viral hepatitis can be reliably differentiated by simple parameters such as gender, gamma-globulin serum levels and AST/ALT ratio.
Address correspondence to Dr R. Ferrari, Dipartimento di Medicina Interna, Cardioangiologia, Epatologia, Alma Mater Studiorum, Università di Bologna, Policlinico S. Orsola-Malpighi, Via Massarenti 9, 40138 Bologna, Italy. e-mail: dr.rofer{at}libero.it