N-acetyl-beta-D-glucosaminidase enzymuria in leukaemia and myelomatosis: effect of treatment in acute myeloblastic leukaemia and myelomatosis in adults.

The activity of the lysosomal hydrolase N-acetyl-beta-D-glucosaminidase (NAG) was measured in the urine of patients with leukaemia or myeloma. Elevated pre-treatment enzymuria was noted in all patient groups with acute myeloblastic leukaemias (AML) FAB type M4 or 5 displaying higher activities than AML patients FAB types M1-3, which in turn were higher than those found in patients with myelomatosis and chronic lymphocytic leukaemia. The ratio of the major isoenzymes of NAG, A/B was reduced significantly only in patients with AML. Following treatment, AML patients who entered remission demonstrated NAG levels which approached normal values. In those AML patients who were either in relapse, in the terminal phase of their illness or treated with aminoglycoside antibiotics, NAG enzymuria was similar to pre-treatment values. A reduction in urinary NAG levels and both serum and urine beta 2 microglobulin concentrations was also observed following treatment in myeloma patients. The use of enzymuria both as a guide to progress towards remission in AML patients and for assessing prognosis and progress in myeloma patients is discussed.