Summary of the Banff 1997 criteria for scoring acute cellular rejection in liver allografts
| Parameter scored | Criteria* | RAI score |
| Portal inflammation | Inflammation in minority of portal tracts, not expanding and mostly lymphocytic | 1 |
| Inflammation in and expanding majority or all portal tracts, mixed lymphocytic including occasional blast/activated lymphocytes and neutrophils, eosinophils | 2 | |
| Inflammation in and expanding majority or all portal tracts, mixed lymphocytic including numerous blast/activated forms and neutrophils, eosinophils, with spillover to interface/periportal hepatocytes | 3 | |
| Bile duct injury/inflammation | Inflammation affecting duct epithelium in minority of portal tracts with mild evidence of epithelial injury such as increased nucleocytoplasmic ratio, or irregular spacing in epithelium | 1 |
| Inflammation affecting duct epithelium in most portal tracts with marked evidence of epithelial injury in few ducts, such as increased nucleocytoplasmic ratio, cytoplasmic vacuolisation, disordered polarity and/or irregular spacing in epithelium | 2 | |
| Inflammation affecting duct epithelium in most portal tracts with marked evidence of epithelial injury in most ducts, such as increased nucleocytoplasmic ratio, cytoplasmic vacuolisation, disordered polarity and/or irregular spacing in epithelium; outright duct necrosis can be seen in some ducts | 3 | |
| Venous phlebitis | Subendothelial lymphocytes in some but not the majority of portal and/or hepatic venules | 1 |
| Subendothelial lymphocytes in most portal and/or hepatic venules | 2 |
The table is modified from the Banff schema for grading liver allograft rejection: an international consensus document.38
*Key features differentiating one score in each parameter from the next higher score are underlined.
RAI, Rejection Activity Index.