EXPRESSION OF NK AND LYMPHOID-ASSOCIATED ANTIGENS IN BLAST CELLS OF ACUTE MYELOBLASTIC-LEUKEMIA

In the present study, the expression of two NK-associated antigens (CD 56 and CD16) together with six 'classically' considered lymphoid-relat ed markers (TDT,CD19,CD10,CD7,CD2, CD4) has been analyzed by appropria te dual combinations in 265 acute myelogenous leukemia (AML) patients. Among the lymphoid markers, CD4 and CD7 were those most frequently ex pressed by AML blast calls (58% and 21.6%, respectively) while the inc idence of positivity for the other markers was lower: CD19 (7.8%), CD1 0 (10.9 %) CD2 (11.4%) and TDT (11.3%). Regarding NK-associated antige ns, CD56 was present in 41% of AML cases analyzed whereas CD16 was det ected in only 23%. All but one of the CD16 + cases coexpressed the CD5 6 antigen. The expression of these antigens was not associated with th e degree of cell differentiation assessed either by morphological or i mmunophenotypical criteria, with the exception of the correlation obse rved between monocytic leukaemias and the expression of the CD4, CD56, and CD16 antigens. Regarding the prognostic value of the markers inve stigated, CD56 expression was associated with a tendency for a better outcome whereas CD7 was the only antigen that had an adverse influence on the survival of AML patients.