Clinical Feature Score
ANA or SMA  
≥ 1:40 +1
≥ 1:80 +2
LKM-1 ≥ 1:40 +2
SLA positive +2
Antibodies absent 0
Serum globulin or IgG  
Above upper normal limit +1
>1.1 upper normal limit +2
Normal 0
Hepatitis viral markers  
Positive 0
Negative +2
Liver histology (evidence of hepatitis is a necessary condition)  
Compatible with AIH +1
Typical AIH +2
Incompatible with AIH 0
Interpretation of aggregate scores*:  
Probable AIH ≥ 6
Definite AIH ≥ 7
*Addition of all antibodies, maximum +2 points.
IgG: Immunoglobulin G; ANA: Anti-nuclear Antibodies; SMA: Smooth Muscle Antibodies; LKM-1: Type 1 Liver-kidney Microsomal Antibodies; SLA: Soluble Liver Antigen antibodies
Table 3: Simplified Scoring System for the diagnosis of AIH.