Acute leukaemia types

Marker patterns in typical 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 pimitive cell type expected in AML AML cells often have markers that reflect this primitive nature. They are not required to identify blast cells if other features (weak CD45 and/or morphology fit) but detecting them can imcrease diagnostic confidence. In AML they are most frequently expressed by less differentiated types. Although these markers are not specific for any given lineage, some are more frequently associated with particular lineages (see notes).
Marker	Expectation	Comment
CD34		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