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Difference between revisions of "CD25"

From www.haemtologyetc.co.uk

 
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CD25 may be expressed by a range of malignant cells (including for example many cases of CLL). It does however have value in specific circumstances:
 
CD25 may be expressed by a range of malignant cells (including for example many cases of CLL). It does however have value in specific circumstances:
  
CD25 is expressed by most cases of hairy cell leukemia and is not generally expressed by variant hairy cell leukemia or splenic marginal zone lymphoma
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* CD25 is expressed by most cases of hairy cell leukemia and is not generally expressed by variant hairy cell leukemia or splenic marginal zone lymphoma
 
   
 
   
The malignant mast cells of systemic mastocytosis express CD25 (normal mast cells generally do not)
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* The malignant mast cells of systemic mastocytosis express CD25 (normal mast cells generally do not)
  
CD25 is strongly expressed by the neoplastic T cells in adult T cell leukemia/lymphoma (ATLL) (although it is expressed also in other T cell disorders, notably T-PLL and Sézary syndrome)
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* CD25 is strongly expressed by the neoplastic T cells in adult T cell leukemia/lymphoma (ATLL) (although it is expressed also in other T cell disorders, notably T-PLL and Sézary syndrome)
 
   
 
   
 
* CD25 should not be considered as lineage or stage-specific, for example expression is seen in AML (possibly 10%) and ALL in 30% (particularly in cases expressing ''BCR-ABL1'').
 
* CD25 should not be considered as lineage or stage-specific, for example expression is seen in AML (possibly 10%) and ALL in 30% (particularly in cases expressing ''BCR-ABL1'').
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File:Rare.png|''Pro-T ALL''|link=Flow cytometry key
 
File:Rare.png|''Pro-T ALL''|link=Flow cytometry key
 
File:Rare.png|''Mature-T ALL''|link=Flow cytometry key
 
File:Rare.png|''Mature-T ALL''|link=Flow cytometry key
File:Poss.png|''AML''|link=Flow cytometry key
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File:Poss.png|''AML*''|link=Flow cytometry key
 
File:Rare.png|''Haemato-gones''|link=Flow cytometry key
 
File:Rare.png|''Haemato-gones''|link=Flow cytometry key
 
</gallery>
 
</gallery>
  
<span style="font-size:80%">''Expression is reported to be associated with ''BCR-ABL1'' expression''</span>
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<span style="font-size:80%">''* Expression is reported to be associated with ''BCR-ABL1'' expression''</span>
  
  

Latest revision as of 15:00, 10 October 2019


Principally a marker of cell activation in different haematopoietic lineages, CD25 has value in several disorders – though in each case be aware that it is not absolutely specific
  • CD25 has recognised value in the diagnosis of hairy cell leukaemia
  • CD25 recognises malignant mast cells
  • It may be valuable to identify the malignant cells of adult T cell leukaemia/lymphoma



Normal expression and function


CD25 is the alpha subunit of the interleukin 2 receptor. When associated with its beta subunit (memory T cells or NK cells) or with beta and gamma subunits (activated T cells or regulatory T cells) the receptor affinity for IL-2 is progressively increased and the receptor activates intracellular signals causing cellular activation. CD25 has a broad expression in the immune system – most frequently following cell activation.


Other relevant information:


In a histological context the marker has a wider diagnostic use: in tissue lymphoma sections staining is seen in anaplastic large cell lymphoma with high frequency and Hodgkin Disease.


Diagnostic role?

CD25 may be expressed by a range of malignant cells (including for example many cases of CLL). It does however have value in specific circumstances:


  • CD25 is expressed by most cases of hairy cell leukemia and is not generally expressed by variant hairy cell leukemia or splenic marginal zone lymphoma
  • The malignant mast cells of systemic mastocytosis express CD25 (normal mast cells generally do not)
  • CD25 is strongly expressed by the neoplastic T cells in adult T cell leukemia/lymphoma (ATLL) (although it is expressed also in other T cell disorders, notably T-PLL and Sézary syndrome)
  • CD25 should not be considered as lineage or stage-specific, for example expression is seen in AML (possibly 10%) and ALL in 30% (particularly in cases expressing BCR-ABL1).

SUMMARY TABLES


1. Expression by acute leukaemias and by haematogones

* Expression is reported to be associated with BCR-ABL1 expression


2. Expression by B-lymphoproliferative disorders

Considered a strong indicator of HCL allowing discrimination from HCLv and MZL


KEY


The indicated expression frequency, indicates the approximate frequency of occurrence in each particular disease type.


Rare.png

rare (<5%)

Poss.png

possible (5-20%)

Mod.png

likely (20-40%)

Freq.png

frequent (40-80%)

Hi.png

expected (>80%)


Where expression level is unusual or characteristic of a disorder this is indicated by text: