CD 45 or LCA is a very commonly used antibody in IHC. CD45 is very useful in immunohistochemistry as it is a useful in aiding diagnosis of undifferentiated neoplams. This is useful as a positive result almost certainly means that the tumour is of lymphoid or plasma origin.

CD45 is found on all cells of hematopoetic origin bar erythocytes. The staining pattern of CD45 is membraneous as shown below.

Picture 1 – CD45 positivity in Lymph nodes

 

CD45 has several different applications. Below are a few examples.

Tumour or cell type	CD 45 + or -
B cell lympohomas	Positive
T cell Lymphomas	Positive
Erythrocytes	Negative
Hodgkin Lymphoma	Negative

There are several different types of T Cell Lymphomas, Below are a few examples of the most common.

Tumour	Most useful IHC antibodies to ID them
Angioimmunoblastic	CD 45, CD2, CD3, Cd4, Cd5, CD7
Lymphoblastic	CD 45, CD3, CD5, CD7
Cutaneous	CD 45, CD2, CD3, Cd4, CD7
Myocosis Fungoiodes	CD 45, CD2, CD3, Cd4, Cd5

There are several different types of B Cell Lymphomas, Below are a few examples of the most common.

Tumour	Most useful IHC antibodies to ID them
Follicular	CD 45, CD20, Bcl-2, Bcl-6, CD10
Mantle Cell	CD 45, CyclinD1, CD20, CD5, Bcl-2
Burkitt	CD 45, CD20, Bcl-6, CD10
Lymphoplasmacytic	CD 45, CD20, Mum1, Bcl-2
Marginal Zone	CD 45, CD20, Mum1, Bcl-2
Diffuse Large Cell	CD 45, CD20, Mum1, Bcl-2, Bcl-6
Hairy Cell leukaemia	CD 45, CD20, Bcl-2, CD11c
Chronic lymphocytic leukaemia	CD 45, CD20, Bcl-2, CD5, CD23