Pancreas
Transplant Grading

Information from Transplant Pathology Internet Services

Grade I: Inflammation of Undetermined Significance

 

Characterized by:
    - sparse, mononuclear inflammation in the fibrous septa
    - infiltrates are usually composed of small lymphocytes or rarely
        a mixture of lymphocytes and plasma cells.
    - eosinophils are not identified.
    - veins, arteries and acini are free of inflammation
    - mild ductal inflammation by itself is not significant without
        - an acinar component or venous endotheliitis.

 

Grade II: Minimal Rejection

 

Characterized by:
    - perivenular inflammatory infiltrates composed of small and large "activated"
        appearing lymphocytes
    - inflammatory cells attach to the endothelium and cause endothelial damage
        with lifting of the endothelial cells from the basement membrane
    - Perivascular infiltrates not associated with endotheliitis are not specific for rejection
        - commonly seen in chronic pancreatitis
        - mild venous endotheliitis may be seen in other situations such as CMV pancreatitis

Rejection should be diagnosed and graded after other possible causes of graft inflammation have been ruled out.

Due to sampling variations and to increase the sensitivity for the diagnosis of rejection, in the absence of venous endotheliitis minimal rejection is diagnosed in the presence of 3 of the following 4 features:

• Septal inflammation composed of "activated" lymphocytes
• Eosinophils
• Focal acinar inflammation
• Ductal inflammation

Grade III: Mild Rejection

 

Characterized by:
    - preferential involvement of the acinar parenchyma by the inflammation with
        associated acinar cell damage
        - not observed in non-specific chronic inflammation or in other
            conditions such as post-transplant lymphoproliferative disorders
        - CMV-related inflammation involving the acinar tissue may resemble the
            changes seen in mild rejection.

    - multiple foci of acinar inflammation

        - composed predominantly of lymphocytes and eosinophils

            with mild evidence of acinar cell damage

                - manifested as drop-out of acinar cells, vacuolization and often apoptosis

    - If there is significant acinar damage

        - admixed neutrophilic infiltrates and microabscesses are not unusual

    - In most cases the acinar inflammation is accompanied by some degree of

        septal inflammation and features described in Grade II.

Grade IV: Moderate Rejection

 

Characterized by:

    - arterial involvement manifested as endotheliitis and/or arteritis
        -occasionally the predominant feature

    - in most cases the morphological features described for Grades II and III

        are also present

Grade V: Severe Rejection

 

Characterized by:
    - presence of areas of multicellular parenchymal necrosis
    - associated with mixed inflammation including numerous neutrophils
    - often has all of the features described described for grades II, III and IV

Rarely:
    - extensive coagulation necrosis
        - differential diagnosis should include:
            - post-transplant lymphoproliferative disorders
            - ischemia
                - manifested in the acinar parenchyma as
                    pale patches of coagulation necrosis that occasionally involve
                    clusters of only few cells
                - often associated some fat necrosis

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Last modified: 03/05/06