Markers used to demonstrate primitive nature in AML
From haematologyetc.co.uk
Table: Markers primarily used to confirm primitive nature in AML
(click on marker name for more details)
| Main markers of primitivity in AML The expression of some markers is typically associated with primitive cells and can help recognise the primitive nature of AML blast cells. Note that these markers may also have some lineage specificity but are not generally used to assign lineage | |
| 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, particular in mare mature monocytic forms where expression may resemble normal monocytes. |
| CD34 | Frequently expressed by AML blast cells (40-80% of cases) - most often in less differentiated forms of AML. Expression is also seen frequently (and often more strongly) in ALL |
| CD117 | Frequently expressed by AML blast cells (70-80% of cases) - where it can support myeloid differentiation, CD117 also has some value in establishing primitive differentiation as it is lost as cells mature |
| Other markers of primitive phenotype: In the context of a proven AML diagnosis a number of markers may be expressed that reflect the primitive nature of the cells. Some of these are more frequently associated with lymphoid disorders, but providing other criteria for AML are met they should simply be considered to show "primitivness". | |
| CD38 | Variable expression in AML cases (around 20%) compared with higher expression on lymphoid blasts (particularly T-ALL). CD38 may identify leukaemia initiating cells and is a potential therapeutic target. |
| HLA-DR | Expressed in around 70-80% of AML cases, but also frequently expressed in ALL. The most valuable aspect of HLA-DR is the absent or weak expression in APL when compared with reactive myeloid cells. |
| TDT | TdT is more often associated with ALL, but the expression by around 20% of AML cases is well recognised, particularly in more primitive forms of the disease. |
| CD7 | Regarded as a pan-T-cell marker expressed throughout T cell development, CD7 is also expressed frequently as an "aberrant" marker in AML where it is best regarded as a marker of their primitive nature |