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CD79b: Difference between revisions

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!colspan="8"|<span style="font-size:100%">'''Expression in primitive cell types'''</font>
!colspan="8"|'''Expression in primitive cell types'''</font>
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! AML !! CMML !! B ALL !! Burkitt || T ALL !! ETP ALL <'''[[ETP ALL|I]]'''> !! MPAL <'''[[MPAL|I]]'''> || Hgns <'''[[Hgns|I]]'''>
!AML!!CMML !!B ALL !!BL ||T ALL !!ETP ALL !!MPAL ||Hgn</span>
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|-<span style="font-size:70%">
|style="width: 12.5%; background: #66e0ff; color:black"|5-20%*
|style="width: 12.5%; background: #66e0ff; color:black"|5-20%*
|style="width: 12.5%; background: #E6FAFF; color:wblack"|<5%
|style="width: 12.5%; background: #E6FAFF; color:wblack"|<5%
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!colspan="8"|'''Expression in mature B cell neoplasms'''
!colspan="8"|'''Expression in mature B cell neoplasms'''
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! CLL !! MCL !!FL!! MZL !! HCL !! DLBCL || LPL !! PCL
! CLL !! MCL !!FL!! MZL !! HCL !! DLBCL || LPL !! PCL
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|-<span style="font-size:70%">
|style="width: 12.5%; background: #004466; color:white"|80-100%*
|style="width: 12.5%; background: #004466; color:white"|80-100%*
|style="width: 12.5%; background: #004466; color:white"|80-100%
|style="width: 12.5%; background: #004466; color:white"|80-100%

Latest revision as of 21:45, 4 July 2023


Summary
CD79b is a pan-B-cell marker expressed from early commitment to B-cell lineage then becoming lost during plasma cell differentiation; CD79b may be used as marker of B-cel lineage, but its more variable expression make it less useful than CD79a or CD19 in this context
The major diagnostic value of CD79b is its characteristically weak-expression in CLL



Normal expression and function

The two forms of CD79 (CD79a and CD79b) each associate directly with the immunoglobulin chains to control signalling from the B-cell receptor. Expression of both CD79a and CD79b is therefore acquired at early B-lymphocyte formation (initially in cytoplasm then membrane) and persist until plasma cell differentiation. However, while both CD79a and CD79b may be considered pan B-cell antigens, expression of CD79b is acquired later and is lost earlier than for CD79a.



Diagnostic role

  • The most useful attribute of CD79b is its variable intensity of expression - in particular the characteristically weak intensity of expression of CD79b in CLL is often used as a diagnostic criterion




SUMMARY TABLES


Note The colour and % refer to the proportion of cases expressing the marker. Additional comments on strength, or site of expression (if relevant) are given below the table. For full details of key click here. For further information about a particular disease state click <I> adjacent to the condition name


Expression in primitive cell types
AML CMML B ALL BL T ALL ETP ALL MPAL Hgn
5-20%* <5% 80-100%** 80-100% <5% <5% 40-80% 80-100%

Notes: **While a good marker of B lineage it may not be expressed in more primitive phenotype ALL, there is also a recognised abberrant expression in AML (particularly cases with t)8;21)


Expression in mature B cell neoplasms
CLL MCL FL MZL HCL DLBCL LPL PCL
80-100%* 80-100% 80-100% 80-100%** 80-100%** 40-80% 80-100% 5-20%***

Notes: Level of expression is important: *low expression in CLL; **typically high expression in HCL; ***generally absent in PCs


Expression in mature T cell neoplasms*
ATLL CTCL/Sezary T-PLL T-LGL NK-LGL
<5% <5% <5% <5% <5%