Neutral maltase: a marker of cell differentiation in human myeloid leukaemias?

S ummary . The neutral maltase activity was determined in granulocytes from normal subjects and patients with chronic or acute myeloid leukaemias. Whereas the enzyme activity is present in normal granulocytes, in chronic or acute leukaemias these cells have markedly decreased and no detectable activity respectively. These data suggest that the variations of the neutral maltase activity observed in myeloid leukaemic cells may be related either to enzymatic modifications occurring in the course of leukaemogenesis or conversely to the stage of cell differentiation reached by the neoplastic granulocytes.