N-acetyl-beta-glucosaminidase activity in normal and acute leukemia blood cells

N-acetyl-beta-glucosaminidase activity was studied by cytochemical means in blood cells of 20 normal controls and in blast cells of 21 cases of acute leukemia. All normal granulocytes and monocytes showed finely granular positivity, whereas the lymphocytes were unreactive or showed various granular positivity patterns. The intensity of enzymic activity was not significantly different in the various subtypes of acute leukemia. However the lymphoblasts showed a characteristic positivity pattern with activity being present both in coarse and fine granules located at one pole of the cell. This allowed them to be distinguished from the other leukemic blasts showing fine granules scattered throughout cytoplasm.