Criteria for Determination of the Rejection Activity Index	
			
Category	Criteria	Score	
Portal Inflammation	Mostly lymphocytic inflammation involving, but not noticeably  expanding, a minority of the triads.
Expansion of most or all of the triads by a mixed infiltrate containing lymphocytes with occasional blasts, neutrophils and eosinophils.
Marked expansion of most or all of the triads by a mixed infiltrate containing numerous blasts and eosinophils with inflammatory spillover into the periportal parenchyma	1
2
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/cytoplasmatic ratio of the epithelial cells
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 cytoplasmatic vacuolization of the epithelium
As above for 2, with most or all of the ducts showing degenerative changes or focal lumenal disruption	1
2
3	
Venous Endothelial Inflammation	Subendothelial lymphocytic infiltration involving some, but not a majority of the portal and/or hepatic venules
Subendothelial infiltration involving most or all of the portal and/or hepatic venules
As above for 2, with moderate or severe perivenular inflammation that extends into the perivenular parenchyma and is associated with perivenular hepatocyte necrosis	1
2
3