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CD4 & CD8
The contribution of CD23 in diagnosis is to help distinguish between cll consistent expression and mcl expression infrequent
*CD23 is not cll-specific and is also expressed on haematological and lymphoma cell types. 


In systemic disease these two co-stimulatory molecules define different functional types of T cell; therefore an altered ratio between CD4 and CD8 cells can indicate systemic disease or immune dysfunction  
normal expression and function  


In neoplasia an expanded populations of CD4 or CD8 cells or T cells with unusual expression patterns of these molecules may represent a malignant clone and the CD4 or CD8 expression may help identify the disease subtype.  
CD23 is the membrane-expressed low-affinity receptor for ige involved in antigen capture and presentation. it affects b-cell growth and differentiation and the activation of monocytes. CD23 is expressed on activated b cells but also platelets eosinophils activated macrophages and follicular dendritic cells.


However restricted CD4 or CD8 expression cannot substitute for molecular clonality analysis.
other relevant information  CD23 is not u8e2809ccll-specificu8e2809d; it may be expressed in lymphoplasmacytic lymphoma marginal zone lymphoma or follicular lymphoma. when CD23 is expressed by mcl the cases may have a more indolent course and an improved outcome.  


Function  
diagnostic role 
   
*CD23 is most frequently used in the distinction between cll and mcl but this difference is not absolute CD23 is expressed by the vast majority 90 of typical cll patients and is generally absent in mcl although it is detected in around 10 of cases where its expression may be bright .
*CD23 may also be expressed by other b-lymphoproliferative disorders although at lower frequency.


CD4 and CD8 are transmembrane-glycoproteins that amplify signal generation by the T-cell receptor. T cells acquire simultaneous expression of both CD4 and CD8 during their early the thymic stage of development, however when the mature t cells enter the circulation they express either CD4 or CD8 only.
summary tables 


CD4 is linked to T-helper cell function interacting with mhc class II expressed for example on dendritic cells or B lymphocytes but is also expressed by immune-presenting cells including monocytes macrophages and dendritic cells.
1. expression by acute leukaemias and by haematogones file rareu82epng  pro-b all  link flow cytometry key file rareu82epng  early pre-b all  link flow cytometry key file rareu82epng  pre-b all  link flow cytometry key file rareu82epng  early b all  link flow cytometry key file rareu82epng  pro-t all  link flow cytometry key file rareu82epng  mature-t all  link flow cytometry key file possu82epng  aml  link flow cytometry key file rareu82epng  haemato-gones  link flow cytometry key  *may be expressed in aml with monocytic differentiation 


CD8 is particularly expressed by cytotoxic cells and interacts with MHC class I expressed on all nucleated cells and is also expressed by natural killer cells and dendritic cells.  
2. expression by b-lymphoproliferative disorders file hiu82epng frame  cll  link flow cytometry key file rareu82epng  pll  link flow cytometry key file possu82epng  mcl  link flow cytometry key file modu82epng  fl  link flow cytometry key file possu82epng  hcl  link flow cytometry key file possu82epng  hclv  link flow cytometry key file rareu82epng  mzl  link flow cytometry key file rareu82epng lpl link flow cytometry key file rareu82epng pcs link flow cytometry
 
CD4 CD8 in health  
*CD4:CD8 ratio for healthy individuals the ratio in blood lies between 1u82e5 and 2u82e5. an inverted ratio is considered an cimmune riskd phenotype occurring in just less than 10 of 20- to 59-year-olds but increasing with age . however there be quite wide variation depending on a range of factors including infection with the hiv virus. * absolute counts these may be more informative than CD4 CD8 ratios the normal CD4 count should be greater than 400 u8cebcl reference range 500-1 500 ; CD8 lymphocyte counts should lie in the range to 200-800 u8cebcl CD4 CD8 in mature t cell neoplasia * CD4 proliferations particularly characterise cutaneous lymphomas and t-pll although t-pll may express both CD4 and CD8 or rarely only CD8 * CD8 proliferation typifies atll although simultaneous CD4 expression may occur and t-lgl ---- '),

Revision as of 15:25, 12 May 2023

The contribution of CD23 in diagnosis is to help distinguish between cll consistent expression and mcl expression infrequent

  • CD23 is not cll-specific and is also expressed on haematological and lymphoma cell types.

normal expression and function

CD23 is the membrane-expressed low-affinity receptor for ige involved in antigen capture and presentation. it affects b-cell growth and differentiation and the activation of monocytes. CD23 is expressed on activated b cells but also platelets eosinophils activated macrophages and follicular dendritic cells.

other relevant information CD23 is not u8e2809ccll-specificu8e2809d; it may be expressed in lymphoplasmacytic lymphoma marginal zone lymphoma or follicular lymphoma. when CD23 is expressed by mcl the cases may have a more indolent course and an improved outcome.

diagnostic role

  • CD23 is most frequently used in the distinction between cll and mcl but this difference is not absolute CD23 is expressed by the vast majority 90 of typical cll patients and is generally absent in mcl although it is detected in around 10 of cases where its expression may be bright .
  • CD23 may also be expressed by other b-lymphoproliferative disorders although at lower frequency.

summary tables

1. expression by acute leukaemias and by haematogones file rareu82epng pro-b all link flow cytometry key file rareu82epng early pre-b all link flow cytometry key file rareu82epng pre-b all link flow cytometry key file rareu82epng early b all link flow cytometry key file rareu82epng pro-t all link flow cytometry key file rareu82epng mature-t all link flow cytometry key file possu82epng aml link flow cytometry key file rareu82epng haemato-gones link flow cytometry key *may be expressed in aml with monocytic differentiation

2. expression by b-lymphoproliferative disorders file hiu82epng frame cll link flow cytometry key file rareu82epng pll link flow cytometry key file possu82epng mcl link flow cytometry key file modu82epng fl link flow cytometry key file possu82epng hcl link flow cytometry key file possu82epng hclv link flow cytometry key file rareu82epng mzl link flow cytometry key file rareu82epng lpl link flow cytometry key file rareu82epng pcs link flow cytometry

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