Baseline data were available in 37 and 31 AIH and 40 and 26 non-AIH subjects to calculate 1999 and 2008 criteria, respectively. Sensitivity and specificity of the simplified criteria were calculated using 1999 criteria as the standard for subjects with available data for both criteria.
The 1999 standard designated 29 of 31 subjects (94 % ) as definite AIH and 2 of 31 subjects (6 % ) as probable AIH. The simplified criteria identified 25 of 31 subjects (81 % ) as definite AIH, 2 of 31 subjects (6 % ) as probable AIH. Only 1 of 5 patients with AIH who presented with fulminant hepatic failure (FHF) was identified by the simplified criteria as having AIH. The 2008 diagnostic criteria had a sensitivity of 87 % and a specificity of 89 % (area under the receiver operating characteristic curve, 0.98). After removing data from patients with FHF from the analysis, the sensitivity increased to 100 % . Modifying the 2008 diagnostic criteria to include either level of globulin or immunoglobulin G resulted in a similar sensitivity (92 % ) and specificity (95 % ) values (area under the receiver operating characteristic curve, 0.99).
The 2008 criteria diagnose AIH in children with high levels of sensitivity and specificity, and are easier to use in the clinic. Diagnosis of AIH in patients who present in FHF requires the 1999 criteria. Levels of globulin and immunoglobulin G can be used interchangeably in the simplified diagnostic criteria.