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Difference between revisions of "CD200"

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*The main value of CD200 is to aid distinction between CLL (consistent expression) and MCL (rare expression)  
 
*The main value of CD200 is to aid distinction between CLL (consistent expression) and MCL (rare expression)  
*It is important to realise that CD200 is not a CLL-specific marker and is also expressed on a wide range of other cell types
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*It is important to realise that CD200 is not a CLL-specific marker and is also expressed on a wide range of other B cell types
  
  
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<span style="color:navy">'''Diagnostic role'''</span>  
 
<span style="color:navy">'''Diagnostic role'''</span>  
  
*CD200 is expressed in chronic lymphocytic leukemia (CLL) including on CLL cells with atypical morphology or atypical expression of other surface markers.
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*CD200 is expressed in chronic lymphocytic leukemia (CLL) including on CLL cells with atypical morphology or atypical expression of other surface markers  
*CD200 is usually absent in mantle cell lymphoma (MCL), making CD200 a particularly useful marker for discrimination between CLL and MCL (note, that expression has been reported in a small number of MCL cases (<5%) so the distinction is not absolute)
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*CD200 is usually absent in mantle cell lymphoma (MCL), making CD200 a particularly useful marker for discrimination between CLL and MCL (note that expression has been reported in a small number of MCL cases (<5%) so the distinction is not absolute)
*CD200 is overexpressed by many different types and is not a lineage- or stage-specifi: CD200 is expressed by B-cell progenitors and nearly all precursor B lymphoblastic leukemias. It is expressed by over 70% of myeloma, and hairy cell leukemia also exhibits a high level of staining in comparison to other B-cell lymphoproliferative disorders (including hairy cell leukemia-variant (HCL-V), marginal zone lymphoma, and lymphoplasmacytic lymphoma).
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*CD200 is overexpressed by many different types and is not a lineage- or stage-specific - CD200 is expressed by B-cell progenitors and nearly all precursor B lymphoblastic leukemias. It is expressed by over 70% of myelomas, and hairy cell leukemia also exhibits a high level of staining in comparison to other B-cell lymphoproliferative disorders (including hairy cell leukemia-variant (HCL-V), marginal zone lymphoma, and lymphoplasmacytic lymphoma)  
*Expression by AML is also recorded and may predict adverse outcome.
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*Expression in AML is also recorded and may predict adverse outcome
  
 
   
 
   

Latest revision as of 15:19, 10 October 2019


CD200 is not lineage specific, it has a particular role in diagnosis of CLL
  • The main value of CD200 is to aid distinction between CLL (consistent expression) and MCL (rare expression)
  • It is important to realise that CD200 is not a CLL-specific marker and is also expressed on a wide range of other B cell types




Normal expression and function

The CD200 molecule (OX-2) is a membrane glycoprotein, broadly the interaction between CD200 and its ligand delivers an inhibitory signal for inflammation in diverse tissues. It is commonly expressed on cells of hematopoietic lineage; specifically macrophages, dendritic cells, neutrophils, mast cells, and eosinophils, but also B cells, and activated T cells.


Diagnostic role

  • CD200 is expressed in chronic lymphocytic leukemia (CLL) including on CLL cells with atypical morphology or atypical expression of other surface markers
  • CD200 is usually absent in mantle cell lymphoma (MCL), making CD200 a particularly useful marker for discrimination between CLL and MCL (note that expression has been reported in a small number of MCL cases (<5%) so the distinction is not absolute)
  • CD200 is overexpressed by many different types and is not a lineage- or stage-specific - CD200 is expressed by B-cell progenitors and nearly all precursor B lymphoblastic leukemias. It is expressed by over 70% of myelomas, and hairy cell leukemia also exhibits a high level of staining in comparison to other B-cell lymphoproliferative disorders (including hairy cell leukemia-variant (HCL-V), marginal zone lymphoma, and lymphoplasmacytic lymphoma)
  • Expression in AML is also recorded and may predict adverse outcome


Other relevant information:


CD200 is also expressed on endothelial neuronal cells and cells of the reproductive organs (ovaries and placental trophoblasts).



SUMMARY TABLES


Expression by acute leukaemias and by haematogones

Notes

In AML there is a correlation with less mature forms


Expression by B-lymphoproliferative disorders

The fairly consistent low level expression in MCL and FCL is useful in diagnosis

Although expressed in HCLv, CD200 is expressed at lower intensity on HCLv compared with HCL



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: