Table 3

Descriptive criteria for diagnosis of autoimmune hepatitis (AIH): adapted from the revised International Autoimmune Hepatitis Group (IAIHG) criteria, 1999103

FeaturesDefinite AIHProbable AIH
Liver histologyInterface hepatitis of moderate or severe activity with or without lobular hepatitis or bridging necrosis. No biliary lesions, granulomas or other prominent changes suggestive of a different aetiologySame as for definite AIH
Laboratory features

  • Any serum aminotransferase abnormality, especially if alkaline phosphatase activity normal.

  • Normal levels of alpha-1-anti-trypsin, copper and caeruloplasmin

As for definite AIH but patients with abnormal levels of copper and caeruloplasmin may be included contingent on the exlusion of Wilson's disease by appropriate other investigations
Serum immunoglobulinsGlobulin, γ-globulin or IgG concentrations >1.5× upper normal limit.Any elevation in globulin, γ-globulin or IgG concentrations above the upper normal limit
Serum autoantibodies

  • ANA, SMA or anti-LKM-1 antibodies at titres ≥1:80.

  • Lower titres acceptable for children, especially anti-LKM-1.

  • Negative AMA.

As for definite AIH but at titres ≥1:40, or presence of other specified autantibodies
Viral markersNo markers of current infection with hepatitis A, B and C virusesSame as for definite AIH
Other exposuresAverage alcohol consumption <25 g/day. No recent use of known hepatotoxic drugs

  • Average alcohol consumption <50 g/day and no recent use of known hepatotoxic drugs.

  • Patients who have consumed larger amounts of alcohol or have had exposure to known hepatotoxic drugs may be considered if ongoing damage after abstinence/withdrawal

  • AMA, antimitochondrial antibodies; ANA, antinuclear antibody; SMA, smooth muscle antibody; LKM-1, liver kidney microsomal-1 antibody.