Relationship of urinary excretion of modified nucleosides to disease status in childhood acute lymphoblastic leukemia.

The levels of urinary excretion of five modified nucleosides were quantitated by high-performance liquid chromatography for 15 normal children and 24 children with acute lymphoblastic leukemia (ALL). Excretion of each nucleoside decreased linearly with age when quantitation was based on urine creatinine content. Patients with childhood ALL at initial diagnosis or in relapse had significantly higher concentrations of 1-methylinosine, N2,N2-dimethylguanosine, 1-methylguanosine, and pseudouridine in their urine when compared to the concentrations in either patients in remission (P less than 0.001, P less than 0.001, P less than 0.01, and P less than 0.05, respectively) or normal controls (P less than 0.001, P less than 0.02, P less than 0.01, and P less than 0.001, respectively). Excretion of 2-pyridone-5-carboxamide-N'-ribofuranoside did not show significant differences. Urinary excretion of 1-methylinosine demonstrated a positive linear relationship with the percentage of blast cells in the bone marrow [correlation coefficient (r) = 0.90]; the other nucleosides had lower degrees of correlation. In comparison, the absolute blast cell count in the peripheral blood showed less correlation to the percentage of blast cells in the bone marrow (r = 0.47) than did four of the five nucleosides. The data demonstrate that excretion of modified nucleosides reflects disease activity in childhood ALL and that the urinary nucleosides could be useful clinical markers for this disease.