Urinary excretion of modified nucleosides in chronic myelogenous leukemia

Urinary excretion of modified nucleosides was measured in 15 patients with Philadelphia chromosome-positive CML to determine the correlation with activity of this disease. Resolution and quantitation of seven nucleosides were accomplished with reversed-phase HPLC. Patients in the stable phase of CML had excretion levels one to two times normal, whereas patients in the blastic phase showed elevations up to 12 times normal. The nucleosides showing the most significant differences in excretion between stable phase and blastic phase were 1-methylinosine, pseudouridine, and N²,N²-dimethylguanosine (p < 0.01, p < 0.001, and p < 0.01, respectively). Nucleoside excretion was also determined in patients with bacterial pneumonia and urinary tract infection for comparison. Serial nucleoside determinations were made in two patients with CML and found to correlate closely with disease activity. The degree of elevation and the correlation with disease activity suggest the potential value of urinary nucleoside quantitation in monitoring patients with CML; in particular, nucleoside excretion may be useful in detecting early blastic transformation.