A polyclonal antibody is now available that works on paraffin sections2. This antibody was raised against a synthetic peptide sequence corresponding to the cytoplasmic region of CD19.
Immunohistochemical expression
This protein is expressed through B lineage development, although downregulated in the terminal differentiation of plasma cells. Using the polyclonal antibody, B-cells of germinal centres and mantle zones stain strongly, with scattered cells staining in the interfollicular areas2. In the spleen, B-cells of marginal zone, germinal centres and mantle zones stain2. Plasma cells also stain, although sometimes weakly. Most plasma cells in the bone marrow are negative2. T-cells and macrophages are reliably negative.
It is reliably expressed by B lineage neoplastic cells, including leukaemias (B-ALL/B-LBL).
|
|
weakly positive |
positive |
||
|
0/22 |
2/22 |
|||
|
0/52 |
5/52 |
|||
|
1/62 |
5/62 |
|||
|
33/692 |
32/692 |
|||
|
4/122 |
7/122 |
|||
|
1/132 |
12/132 |
|||
|
18/562 |
30/562 |
|||
|
4/102 |
3/102 |
|||
|
0/32 |
3/32 |
|||
|
1/42 |
0/42 |
|||
|
0/32 |
2/32 |
|||
|
2/52 |
2/52 |
|||
|
0/62 |
0/62 |
|||
|
Total |
64/1942 |
103/1942 |
||
|
|
|
|
||
|
1/102 |
0/102 |
|||
|
2/72 |
0/72 |
|||
|
|
|
|
||
|
1/62 |
0/62 |
|||
|
0/182 |
0/182 |
|||
|
0/102 |
0/102 |
|||
|
0/32 |
0/32 |
|||
|
0/12 |
0/12 |
|||
|
0/12 |
0/12 |
|||
|
Total |
1/392 |
0/392 |
||
Negativity may be useful as a marker of neoplasia in plasma cells2, in conjunction with positivity for CD56 and light chain restriction.
References
Last updated 18.2.06
SMUHT/PW Bishop