Actions

Extra: Difference between revisions

From haematologyetc.co.uk

No edit summary
No edit summary
Line 1: Line 1:
FMC7


The FMC7 antibody recognises an epitope of CD20 that has a more restricted pattern of expression than the parent molecule. FMC7 has high expression on late-stage b-cell neoplasms such as hairy-cell leukaemia or MZL and can be used to indicate their possible presence; however low level of FMC7 expression is frequent on other B-cell disorders so care is required in interpretation.
<div style="background-color: #E0EEEE; {{round corners}} padding: 2em 2em;  margin-right: 5px;">


What is its normal function and expression 


The identity of the FMC7 antigen was unclear for many years before being identified as an epitope of the CD20 molecule. FMC7 never received a CD classification number and retains the initials of the laboratory where it was raised: the  Flinder  Medical  Centre. The particular function of FMC7 is not known, but like the CD20 molecule the FMC7 antigen is expressed by normal B-lymphocytes from the late pre-B-cell stage of development until their terminal differentiation and so is effectively a pan b-cell antigen that is particularly associated with late B cells that have features of activation. 
:<span style="color:navy">'''Summary'''</span>


What is its diagnostic role  
:Although CD15 is expressed in a range of haematological cell types, the main practical use for the marker is in the recognition of cells that have granulocytic or monocytic features. For this reason CD15 has a role in lineage distinction in AML. CD15 was originally described as the Lewis blood group antigen: Sialyl Lewis X. Deficiency of CD15 causes the clinical disorder Leukocyte Adhesion Deficiency Type 2.


*FMC7 is widely expressed in B-NHL particularly where there is strong CD20 expression.
*CD20 tends to have low expression on CLL but higher expression on other B-cell types particularly HCL, MCL and MZL
*FMC7 therefore is most often used as an alert to draw attention to such disorders


Summary tables 
</div>


1. expression by acute leukaemias and by haematogones
rare  pro-b all 
rare  early pre-b all 
rare  pre-b all 
hi  b-all 
rare  pro-t all 
rare  mature-t all 
rare  aml 
poss  haemato-gones


2. expression by b-lymphoproliferative disorders
:<span style="color:navy">'''Background'''</span>


poss
:CD15 is a carbohydrate important in the initial phases of cell-to-cell adhesion known in this context as e-selectin .
cll * 
 
hi  pll** 
 
hi  mcl 
:<span style="color:navy">'''Diagnostic Use'''</span>
freq  fl 
 
hi  hcl**
*xxxxx
hi  hclv ** 
 
hi  mzl 
 
hi  lpl 
 
poss  pcs
-----

Revision as of 09:48, 30 May 2023


Summary
Although CD15 is expressed in a range of haematological cell types, the main practical use for the marker is in the recognition of cells that have granulocytic or monocytic features. For this reason CD15 has a role in lineage distinction in AML. CD15 was originally described as the Lewis blood group antigen: Sialyl Lewis X. Deficiency of CD15 causes the clinical disorder Leukocyte Adhesion Deficiency Type 2.



Background
CD15 is a carbohydrate important in the initial phases of cell-to-cell adhesion known in this context as e-selectin .


Diagnostic Use
  • xxxxx


Retrieved from ‘https://haematologyetc.co.uk/index.php?title=Extra&oldid=1459’