title: Type 1 autoimmune hepatitis: patterns of clinical presentation and differential diagnosis of the 'acute' type.
abstract: BACKGROUND
  Autoimmune hepatitis (AIH) has three different presentations: chronic, acute and asymptomatic.
  
  
  OBJECTIVE
  To evaluate AIH presentation in Italian patients and investigate criteria that differentiate between acute-type AIH and acute viral hepatitis.
  
  
  METHODS
  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, gamma-GT, albumin or gamma-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 gamma-globulin levels (26.9 vs. 13.4 g/l, p < 0.0001) and AST/ALT ratio (1.20 vs. 0.61, p < 0.0001).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Dipartimento di Medicina Interna, Alma Mater Studiorum, Università di Bologna, Policlinico S. Orsola-Malpighi, Bologna, Italy. dr.rofer@libero.it
authors.forename: R
authors.initials: R
authors.lastname: Ferrari
authors.forename: G
authors.initials: G
authors.lastname: Pappas
authors.forename: D
authors.initials: D
authors.lastname: Agostinelli
authors.forename: P
authors.initials: P
authors.lastname: Muratori
authors.forename: L
authors.initials: L
authors.lastname: Muratori
authors.forename: M
authors.initials: M
authors.lastname: Lenzi
authors.forename: G
authors.initials: G
authors.lastname: Verucchi
authors.forename: F
authors.initials: F
authors.lastname: Cassani
authors.forename: F
authors.initials: F
authors.lastname: Chiodo
authors.forename: F B
authors.initials: FB
authors.lastname: Bianchi
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002908:Chronic Disease; D003937:Diagnosis, Differential; D005260:Female; D019693:Hepatitis, Autoimmune / Q000175:diagnosis*; D006525:Hepatitis, Viral, Human / Q000175:diagnosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D000637:Transaminases / Q000097:blood; D005719:gamma-Globulins / Q000032:analysis
chemical_list: D015415:Biomarkers; D005719:gamma-Globulins; D000637:Transaminases