Diagnostic significance of lysosomal enzymes in different types of leukemias.

The activities of seven different leukocyte hydrolases were studied in 19 patients and ten controls. There was a strong positive correlation between the monocyte count and the activities of the lysosomal enzymes (N-acetyl-beta-glucosaminidase, alpha-fucosidase, beta-galactosidase, and alpha-mannosidase). High alpha-fucosidase and alpha-mannosidase activities were also found in the eosinophilic granulocytes. Using simple commercially available synthetic substrates, it is possible to study the activities of the lysosomal enzymes in different types of leukemias and to recognize the monocytic leukemias even when they present with very immature precursor cells in the peripheral blood.