Immunocytochemistry (ICC)

Determining the immunophenotype (T vs. B cell) of canine lymphoma cases has become the standard of care because it can help to guide therapy and prognosis. Methods for determining the immunophenotype of lymphoma include flow cytometry, PCR for analysis of antigen receptor rearrangement (PARR), ICC, and immunohistochemistry (IHC).

 

The sample required for ICC submission is simply 4 adequately cellular, unstained, air-dried glass slides prepared the same way as those for standard cytologic evaluation. ICC analysis does not require overnight shipping of cells in a fluid medium (as with flow cytometric analysis) or an incisional biopsy (as with IHC). See below for examples of ICC stains with interpretations.

 

We routinely use antibodies for CD3 (T cell marker) and CD21 (B cell marker).  For cases that are negative for these routine markers, we also use antibodies for Pax5 (B cell marker) and CD18 (a leukocyte marker that is strongly expressed by histiocytic cells).


Wright Stain


CD21


CD3

The immunostained cells have intense positive membrane staining (brown) for CD21, but are negative for CD3 –
results consistent with B-cell lymphoma.

Wright Stain

CD21

CD3

The immunostained cells have intense positive membrane staining (brown) for CD3, but are negative for CD21 –
results consistent with T-cell lymphoma.