Acute leukaemia types
From haematologyetc.co.uk
1. Establishing the primitive nature of AML blast cells (CD45 gating and primitive markers) click to visit section 2. Basic AML phenotype (expected markers expressed by most AML cases) click to visit section
- Section 3: Additional valuable markers (confirming AML in difficult cases, or subtype identification)
- Section 4: Frequent abberent markers in AML (Abberrent makers that are frequently encountered)
- Section 6: Important additional notes (recognising difficult subtypes and clues suggesting MPAL or ETP-ALL)
MARKERS USEFUL TO CONFIRM PRIMITIVE NATURE OF BLAST CELLS | |
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Useful markers of primitive nature
(1) Typically AML blasts have low CD45 expression and cause low side scatter. This means that they form a relatively uniform and distinctive population that is clearly separate from that of lymphocytes on CD45/SSc plots (for further details see this section) also not all AML forms may fit this pattern - particularly APL and monocytic AML. | |
CD45 | A marker expressed by all leukocytes and their precursors. In AML expression is characteristically "weak" i.e. significantly less intense than normal lymphocytes or monocytes. In monocytic AML expression may be stronger. |
CD34 | Frequently expressed by AML blast cells (40-80% of cases) - most often in less differentiated forms of AML. Expression is also seein frequently (and often more strongly) in ALL |
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MARKERS USEFUL TO CONFIRM MYELOID LINEAGE OR DIFFERENTIATION | |
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Frequently expressed "general" markers of myeloid lineage
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MPO | A strong lineage marker for AML (expressed in around 80% of cases) but generally in those with granulocytic maturation. When detected by flow cytometry is diagnostic of myeloid differentiation (either AML or MPAL) |
CD117 | An early marker of myeloid lineage, seen in up to 80% of AML and vauable in recognising more primitive differentaiion forms (note that aberrant expression is seen in up to 20% of ALL cases) |
CD33 | A good marker for AML, particularly for those cases with granulocytic maturation, CD33 is often less strongly expressed in AML with monocytic dfferentiation and strongly expressed in APL. |
CD13 | A good lineage marker for AML that is acquired a little later in differentation than CD117 or CD33; expression of CD13 is often higher than CD33 in AML with monocytic differentiation. |
Confirmatory markers of AML or markers of subtype
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Granulocytic lineage markers | |
CD10 | One of tne of the first lineage-markers acquired in AML with good relative specificity |
CD11b | One of tne of the first lineage-markers acquired in AML with good relative specificity |
Monocytic lineage markers | |
CD11c | One of tne of the first lineage-markers acquired in AML with good relative specificity |
CD14 | A good marker for AML that is often less strongly expressed in monocytic forms |
CD64 | A good lineage marker for AML aquired a little later, higher than CD13 in monocytic forms |
Erythroid lineage markers | |
CD14 | A good marker for AML that is often less strongly expressed in monocytic forms |
CD64 | A good lineage marker for AML aquired a little later, higher than CD13 in monocytic forms |
Megakaryocytic lineage markers | |
CD14 | A good marker for AML that is often less strongly expressed in monocytic forms |
CD64 | A good lineage marker for AML aquired a little later, higher than CD13 in monocytic forms |
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NON MYELOID MARKERS FREQUENTLY "ABERENTLY" EXPRESSED IN AML | |
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Markers of lymphoid lineage indicating primitive dfferentiation in AML
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TDT | Expressed in some cases of AML (5-20%) particularly in less differentiated blast cells, often on a sub-population of cells. More typically associated with primitive ALL blast cells. |
CD7 | Predominantly seen as a T-cell antigen, CD7 tends may be expressed by AML blasts (20-40%) where it most often indicates a more primitive forms or MPAL. CD7 is most consistently a marker of T-lineage (including T-ALL and more mature froms). |
Markers of lymphoid differentation abererantly expressed in AML
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TDT | Expressed in some cases of AML (5-20%) particularly in less differentiated blast cells, often on a sub-population of cells. More typically associated with primitive ALL blast cells. |
CD7 | Predominantly seen as a T-cell antigen, CD7 tends may be expressed by AML blasts (20-40%) where it most often indicates a more primitive forms or MPAL. CD7 is most consistently a marker of T-lineage (including T-ALL and more mature froms). |
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IMPORTANT ADDITIONAL POINTS | |
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Useful markers of primitive nature
(1) Typically AML blasts have low CD45 expression and cause low side scatter. This means that they form a relatively uniform and distinctive population that is clearly separate from that of lymphocytes on CD45/SSc plots (for further details see this section) also not all AML forms may fit this pattern - particularly APL and monocytic AML. | |
CD45 | A marker expressed by all leukocytes and their precursors. In AML expression is characteristically "weak" i.e. significantly less intense than normal lymphocytes or monocytes. In monocytic AML expression may be stronger. |
CD34 | Frequently expressed by AML blast cells (40-80% of cases) - most often in less differentiated forms of AML. Expression is also seein frequently (and often more strongly) in ALL |