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Acute leukaemia types: Difference between revisions

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|colspan="1" style = "font-size:90%; color:black;" |'''[[CD34]]'''
|colspan="1" style = "font-size:90%; color:black;" |'''[[CD34]]'''
|colspan="1" style = "background:#006699; color:white;"|>70% of cases
|colspan="1" style = "background:#006699; color:white; font-size:80%;"|>70% of cases
|colspan="1" style = "font-size:84%;"|Frequently expressed, most often in less differentiated forms of AML. Expression '''often less intense than in lymphoid leukaemias'''
|colspan="1" style = "font-size:84%;"|Frequently expressed, most often in less differentiated forms of AML. Expression '''often less intense than in lymphoid leukaemias'''
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Revision as of 10:29, 18 July 2023

Expression guide: acute myeloid leukaemia
Expected expression of CD45 in AML
CD45 expression in AML is "weak" i.e. significantly less intense than normal T cells, B cells or monocytes. The typically low side scatter of most blast cells means that myeloid blast cells tend to form a relatively uniform population that is clearly separated from that of lymphocytes on CD45/SSc plots.


Atypical expression may be seen in APL and monocytic AML and occasionally other types

Markers of primitive cell type frequently expressed in AML


AML cells often have markers that reflect thier primitive nature. They are absent in many cases, so are not required to identify blast cells if other features fit (weak CD45 and/or blast cell morphology), but detecting them can increase diagnostic confidence. In AML these markers are most frequently expressed by less differentiated types.

*Note while not fully specific for any given lineage, some are more frequently associated with particular lineages so may contribute to lineage assignment in difficult cases (see comments).

Marker Expectation Comment
CD34 >70% of cases Frequently expressed, most often in less differentiated forms of AML. Expression often less intense than in lymphoid leukaemias
TDT Expressed particularly in less differentiated forms of AML. Often on a sub-population of cells; expression usually less intense than in lymphoid leukaemias.
CD7 Similar to TdT, CD7 expression is recognised on a proportion of AML, usually those with less differentiated phenotype. Most consistently expressed in T-ALL.

Markers with very strong lineage specificity in AML
While not expressed by all cases, when detected by flow cytomwtry MPO can be considered to be lineage-defining marker in AML (or establishing myeloid lineage in MPAL).
Marker Expectation Comment
MPO A strong lineage marker for AML when detected by flow cytometry (though potentially less so by immunocytochemistry)
Lineage markers in AML that with relatively high speificity
These markers are each expressed by many cases (around 80% for each marker), they have high specificity although abberrent expression in ALL is feequent (overall 10-20% for any individual marker)).
Marker Expectation Comment
CD117 One of tne of the first lineage-markers acquired in AML with good relative specificity
CD33 A good marker for AML that is often less strongly expressed in monocytic forms
CD13 A good lineage marker for AML aquired a little later, higher than CD13 in monocytic forms
Other markers helpful in detecting myeloid lineage (often in AML subtypes)
These markers have less general value in diagnosis, but can be useful in subtype selection or in cases whwere lineage is ambiguous.
Marker Expectation Comment
CD10 Gran One of tne of the first lineage-markers acquired in AML with good relative specificity
CD11b Gran One of tne of the first lineage-markers acquired in AML with good relative specificity
CD11c Mono One of tne of the first lineage-markers acquired in AML with good relative specificity
CD14 Mono A good marker for AML that is often less strongly expressed in monocytic forms
CD64 Mono A good lineage marker for AML aquired a little later, higher than CD13 in monocytic forms