A panel of experts in liver transplantation related fields met in Banff, Canada in 1995. They agree on a common nomenclature and a set of histopathologic criteria for the grading of acute liver allograft rejection.
Histologic Criteria for Acute Rejection on core needle biopsies: 2 or more of the following:
(1) mixed but predominantly mononuclear portal inflammation, containing blastic (activated) lymphocytes, neutrophils and frequently eosinophils
(2) bile duct inflammation and damage
(3) subendothelial inflammation of portal veins or terminal hepatic venules
|
Histologic Findings |
Descriptive Term |
Numerical Term |
|
portal inflammatory infiltrate that fails to meet the criteria for the diagnosis of acute rejection |
indeterminate |
|
|
rejection infiltrate in a minority of the triads that is generally mild and confined within the portal spaces |
mild |
Grade I |
|
rejection infiltrate, expanding most or all of the triads |
moderate |
Grade II |
|
rejection infiltrate, expanding most or all of the triads, with spillover into periportal areas and moderate to severe perivenular inflammation that extends into the hepatic parenchyma and is associated with perivenular hepatocyte necrosis |
severe |
Grade III |
Indeterminate:
(1) restricted to cases that have a minor degree of cellular infiltration that could possibly represent low grade or early acute rejection but which fails to meet the minimal diagnostic criteria
(2) should not be used for cases in which one is unsure whether the inflammation is related some other condition such as chronic hepatitis C
Rejection Activity Index
|
Parameter |
Criteria |
Score |
|
portal inflammation |
mostly lymphocytic 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 blastic lymphocytes, neutrophils and eosinophils |
2 |
|
|
marked expansion of most or all of the triads by a mixed infiltrate containing numerous blastic lymphocytes 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-to-cytoplasmic ratio of the epithelial cells |
1 |
|
|
most or all of the ducts are infiltrated by inflammatory cells. More than an occasional duct shows degenerative changes, such as nuclear pleopmorphism, disordered polarity and cytoplasmic vacuolization of the epithelium |
2 |
|
|
as for 2, with most or all of the ducts showing degenerative changes or focal luminal 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 |
2 |
|
|
subendothelial infiltration involving most or all of the portal and/or hepatic venules, with moderate or severe perivenular inflammation that extends into the perivenular parenchyma and is associated with perivenular hepatocyte necrosis |
3 |
rejection activity index (RAI) =
= (points for portal inflammation) + (points for bile duct inflammation) + (points for venous endothelial inflammation)
Interpretation:
• minimum score: 0
• maximum score: 9
• A score of 0 indicates no rejection.
• A score <= 4 indicates mild acute rejection.
• The breakpoints for moderate and severe rejection were unclear in the paper.
Specialty: Gastroenterology
ICD-10: ,
