DIAGNOSTIC-VALUE OF BLAST CELL IMMUNOPHEN OTYPING IN ADULT ACUTE MYELOID LEUKEMIAS

The expression of myeloid- and lymphoid-associated cell surface antige ns was determined on the blast cells from 27 adult patients with acute myeloid leukemias (AML) classified according to the FAB system. A pan el of 18 monoclonal antibodies (MoAb) was tested in indirect immunoflu orescence. Distinctive patterns of the markers expression reffering to morphologically and cytochemically defined FAB subgroups were establi shed. 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 bla sts constantly expressed HLA-Dr, CD14, seldom CD34. in M4 cases they w ere positive for CD13, CD15 and MoAb BCA-09. FAB M6 was char-acterized by reactivity with MoAb HAE9. Immu-nophenotyping is useful for recogn ition of myeloid lineage commitment and particularly in determina-tion of maturation level of the malignant cells in AML.