Objective The diagnostic criteria of autoimmune hepatitis (AIH) were recently modified by the International Autoimmune Hepatitis Group. This study was performed to assess the impact of the revised scoring system on the diagnosis of AIH.
Patients and Methods We re-analyzed the clinical features of 89 patients diagnosed as AIH in Nagasaki Prefecture, Japan, using the revised scoring system, and compared the scores and final diagnosis with our previously published results using the original system.
Results Of the 89 patients with AIH, 40 (45%) were classified using the new system as "definite" AIH, 41 (46%) as "probable" AIH, and 8 (9%) patients were categorized as "others". Of these, 37 (42%), 35 (39%), and 4 (4%) patients who were classified as "definite", "probable", and "others" by the original system remained in the same category by the revised system, respectively. However, 3, 4, and 6 patients were re-categorized as "definite" from "probable", "others" from "probable", and "probable" from "definite", respectively. The difference in aggregate scores between the above two systems ranged from -5 to +2. The main contributing factors to the changes in aggregate AIH score were "other autoimmune disease(s)" and "interface hepatitis without lobular involvement and bridging necrosis on liver histology". However, the main contributing factors to the demotions from "definite" to "probable" and form "probable" to "others" were those related to the characteristics of biliary diseases, i.e., antimitochondrial antibody positive, biliary changes in liver histology, and alkaline phosphatase: aspartate aminotransferase ratio between 1.5 and 3.0. Moreover, two patients who had no histological evidence of AIH were both re-categorized as "others" from "probable" AIH.
Conclusion Our results indicated that the diagnosis, whether based on the revised or original system, was the same in the majority of AIH patients, but the revised scoring system excluded cases who had features suggestive of biliary diseases from "definite" AIH, and also confirmed that a diagnosis of "definite" AIH should not be made without liver histology.
(Internal Medicine 39: 1008-1012, 2000)