Table 5.

Proposed criteria for the histologic scoring of autoimmune hepatitis by Balitzer et al. [28].

Histology score 0	Features not observed in autoimmune hepatitis: florid duct lesion (primary biliary cholangitis), bile duct loss, or copper/CK7 positivity (latter applicable only in cases without any bridging fibrosis)
Histologic score 1 *	(1) Hepatitis with mild or moderate necroinflammatory activity with any one of the following: (a) Ishak A2 (mild/moderate interface activity) (b) Ishak B1 (focal confluent necrosis) (c) Ishak C2 (2–4 foci of lobular activity per 10×) (2) CK7 and negative copper stains (applicable only for cases with Ishak fibrosis score less than 3, this feature is not applicable to acute cases)
Histologic score 2	Hepatitic picture with any one of the following: (1) Numerous plasma cells or in clusters (2) High necroinflammatory activity featuring at least one of the following: (a) Ishak score A3 or higher (at least moderate interface activity) (b) Ishak B2 or higher (confluent necrosis in zone 3 or beyond) (c) Ishak C3 or higher (5 or more foci of lobular activity per × 10)

Adapted from Balitzer et al. [28] * Both (1) and (2) are necessary for a histologic score of 1, except in cases with acute presentation when biliary disease is not a consideration and these stains are not relevant.