PURINE DEGRADATIVE ENZYMES AND TERMINAL TRANSFERASE IN ACUTE MYELOGENOUS LEUKEMIA - CLINICAL RELEVANCE

Intracellular adenosine deaminase (ADA), purine nucleoside phosphoryla se (PNP) and terminal deoxynucleotidyl transferase (TdT) activities we re investigated in adult patients with acute myelogenous leukemia (AML ) in order to relate these enzymatic activities to the stage of differ entiation and maturation and to the clinical outcome of AML. Both ADA and PNP were measured spectrophotometrically using the method of Hopki nson et al.,25 and TdT was investigated using liquid scintillation tec hnique15,16 with slight modification. The level of ADA was above norma l in patients with AML whereas the level of PNP and the PNP/ADA ratio were below normal. Short survival was observed in the majority of the patients with markedly increased levels of ADA and decreased levels of PNP and PNP/ADA. Normal patients and patients with AML had no signifi cant differences in TdT activity. Significant differences in ADA, PNP and TdT among AML subtypes were not observed. The levels of ADA and PN P seemed to reflect the clinical severity of this disease.