Grading of acute liver damage
| Global assessment | Criteria |
| 0: None | No portal inflammation |
| I: Minimal/indeterminate | Portal inflammatory infiltrate is in a minority of the portal triads, which is minimal |
| II: Mild | Inflammatory infiltrate in 50% of the triads, which is generally mild, and confined within the portal spaces |
| III: Moderate | Inflammatory infiltrate, expanding most or all of the triads, and associated with mild interface and lobular activity |
| IV: Severe | As above for moderate, with spillover into periportal areas and moderate to severe perivenular inflammation that extends into the hepatic parenchyma and is associated with perivenular hepatocyte necrosis |
| Global assessment | Criteria |
| 0: None | No portal inflammation |
| I: Minimal/indeterminate | Portal inflammatory infiltrate is in a minority of the portal triads, which is minimal |
| II: Mild | Inflammatory infiltrate in 50% of the triads, which is generally mild, and confined within the portal spaces |
| III: Moderate | Inflammatory infiltrate, expanding most or all of the triads, and associated with mild interface and lobular activity |
| IV: Severe | As above for moderate, with spillover into periportal areas and moderate to severe perivenular inflammation that extends into the hepatic parenchyma and is associated with perivenular hepatocyte necrosis |