Differential excretion of modified nucleosides in adult acute leukemia.

Excretion of modified nucleosides in urine was measured in 23 adults with acute leukemia to determine correlation of nucleoside excretion with disease activity. In addition, differences in excretion between patients with acute lymphoblastic leukemia (ALL) and patients with acute myeloid leukemia (AML) were established. Six modified nucleosides were resolved and quantitated by reversed-phase high-performance liquid chromatography (HPLC). Patients with ALL at initial diagnosis or in relapse had significantly higher concentrations of 1-methylinosine and N2,N2-dimethylguanosine in their urine compared to patients in remission (p less than 0.01, p less than 0.05, respectively). One patient with ALL was followed with serial nucleoside determinations over a period of 18 mo; nucleoside excretion correlated closely with disease activity. Nucleoside excretion in patients with AML did not change significantly with disease activity. Considering only those patients at initial diagnosis or in relapse, excretion of 1-methylinosine and N2,N2-dimethylguanosine was significantly higher in ALL than in AML (p less than 0.01, p less than 0.05, respectively). Thus, urinary excretion of 1-methylinosine and N2,N2-dimethylguanosine by adults with acute leukemia may prove to be valuable clinically in following disease activity in patients with ALL and in distinguishing patients with ALL from those with AML.