Rejection Activity Index
Liver Transplantation

Indeterminate Portal and/or perivenular inflammation related to alloreactivity but without sufficient injury to qualify for mild acute rejection
Mild Generally mild rejection type inflammation in a minority of portal or perivenular areas; Portal inflamation mostly confined to portal spaces and no hepatocyte dropout or confluent necrosis present in perivenular areas
Moderate Rejection type inflammation expanding most or all portal tracts and/or perivenular areas; hepatocyte necrosis/confluent necrosis limited to a minority of perivenular areas
Severe Similar to moderate rejection with additional features of spillover into periportal areas and/or moderate to severe perivenular inflammation extending into hepatic parenchyma with hepatocyte necrosis/confluent necrosis involving a majority of perivenular areas
Category Criteria Score
Portal Inflammation Mostly lymphocytic inflammation involving, but not noticeably expanding, a minority of the triads 1
Expansion of most or all of the triads, by a mixed infiltrate containing lymphocytes with occasional blasts, neutrophils and eosinophils (If eosinophils are conspicuous and accompanied by edema and prominent microvascular endothelial cell hypertrophy consider possibility of acute antibody-mediated rejection) 2
Marked expansion of most or all of the triads by a mixed infiltrate containing blasts and eosinophils with inflammatory spillover into the periportal parenchyma 3
Bile Duct Inflammation Damage A minority of the ducts are cuffed and infiltrated by inflammatory cells and show only mild reactive changes such as increased nuclear:cytoplasmic ratio of the epithelial cells 1
Most or all of the ducts infiltrated by inflammatory cells. More than an occasional duct shows degenerative changes such as nuclear pleomorphism, disordered polarity and cytoplasmic vacuolization of the epithelium 2
As above for 2, with most or all of the ducts showing degenerative changes or focal lumenal disruption 3
Venous Endothelial Inflammation Subendothelial lymphocytic infiltration involving some, but not a majority of the portal and/or hepatic venules 1
Subendothelial infiltration involving most or all of the portal and/or hepatic venules with or without confluent hepatocyte necrosis/dropout in a minority of perivenular regions 2
As above for 2, with moderate or severe perivenular inflammation that extends into the perivenular parenchyma and is associated with perivenular hepatocyte necrosis involving a majority of perivenular regions 3
Total RAI Score = _/9
Reference: Demetris AJ et al. 2016 Comprehensive Update of the Banff Working Group on Liver Allograft Pathology: Introduction of antibody-mediated rejection. Am J Transplant 2016;16:2816-28335.

Please mail comments, corrections or suggestions to the TPIS administration at the UPMC.

Last Modified: Thu Jun 18 10:14:08 EDT 2009