Diagnostic value and utility of the simplified International Autoimmune Hepatitis Group criteria in acute‐onset autoimmune hepatitis

Background: The diagnosis of autoimmune hepatitis (AIH) is already difficult, and that of acute‐onset AIH with atypical features is even more challenging, even though the revised original diagnostic criteria created by an international AIH group were widely accepted and incorporated into clinical practice. Aims: Recently, simplified diagnostic criteria were proposed. We compared the performance parameters of the simplified scoring system in patients with acute‐onset AIH and examined its usefulness and limitations. Methods: Fifty‐five patients with acute‐onset AIH (29 non‐severe, 14 severe and 12 fulminant) were assessed according to the simplified scoring system and compared with the revised original one. Results: Of the 55 patients, 22 (40%) were diagnosed as ‘definite’ AIH, 28 (51%) as ‘probable’ and five (9%) as ‘non‐diagnostic’ based on the revised original scoring system. By the simplified scoring system, six (11%) were diagnosed as ‘definite’ AIH, 16 (29%) as ‘probable’ and 33 (60%) as ‘non‐diagnostic’. Anti‐nuclear antibody titres did not differ among the three groups. The immunoglobulin G level was higher in fulminant than in non‐severe patients (P=0.01). Sixty‐five per cent showed acute hepatitis (massive necrosis, submassive necrosis and severe acute hepatitis) and 35% showed chronic hepatitis. Conclusions: The revised original scoring system performed better in patients with acute‐onset AIH than the simplified scoring system.