Diagnostic value of blast cell immunophenotyping in adult acute myeloid leukemias

The expression of myeloid- and lymphoid-associated cell surface antigens was determined on the blast cells from 27 adult patients with acute myeloid leukemias (AML) classified according to the FAB system. A panel of 18 monoclonal antibodies (MoAb) was tested in indirect immunofluorescence. Distinctive patterns of the markers expression reffering to morphologically and cytochemically defined FAB subgroups were established. The blast cells in FAB M1 and M2 were HLA-Dr(+), CD13(+), CD14(-) and distin-guished by CD34 and CD15 expression. In FAB M4 and M5 blasts constantly expressed HLA-Dr, CD14, seldom CD34. in M4 cases they were positive for CD13, CD15 and MoAb BCA-09. FAB M6 was char-acterized by reactivity with MoAb HAE9. Immu-nophenotyping is useful for recognition of myeloid lineage commitment and particularly in determina-tion of maturation level of the malignant cells in AML.