Surface marker analysis and flow cytometric studies of acute nonlymphocytic leukemias in children and young adults

Bone marrow cells from eight children and young adults with acute nonlymphocytic leukemia (ANLL) were classified by morphological and cytochemical criteria. The expression of receptors for complement (C3) and IgG Fc, the binding of immunoglobulin to the surface of leukemic blasts, and the phagocytic ability were investigated and compared with the differentiation/maturation of cells of normal myeloid and monocytic lineages. Cells from two patients with monocytic leukemia exhibited IgG Fc receptors in high proportions. The stage of maturation or differentiation as evaluated by the expression of surface markers did not correlate morphologically with the determined state of maturation in the remaining cases. Simultaneous measurements of cellular RNA and DNA, using flow cytometry, were performed on five patients. An increase in RNA content of leukemic cells was detected in all patients and evidence of aneuploidy was observed in three patients. The cellular RNA content of ANLL was higher than that of ALL. This technique, therefore, appears to be useful as an additional tool for the discrimination of ALL from ANLL and for the rapid detection of aneuploidy.