Urinary Excretion of β-Aminoisobutyrate and Pseudouridine in Acute and Chronic Myeloid Leukemia

End products of nucleic acid metabolism including βaminoisobutyrate (β-AIB) and pseudouridine (ψ-Urd) have been considered as potential biochemical markers for cancer. The urinary excretion of both metabolites was investigated in abnormal hematopoietic conditions including 26 patients with acute myeloid leukemia(AML)and chronic myeloidleukemia(CML) and was compared to that of 25 healthy controls. β-AIB excretion in CML was directly correlated to the leukocyte count, the indicator of tumor cell mass. β-AIB excretion was elevated in 27 and 75% of untreated AML and CML cases, respectively. Marrow blast cell content tended to correlate positively with ψ-Urd excretion in AML. ψUrd excretion was elevated in 82 and 87% of untreated AML and CML, respectively.Turnover of hematopoietic cells seemed to be a determinant for β-AIB excretion, indicating higher cell turnover in CML patients compared to that in AML patients and in controls. With cytostatic treatment, excretion levels of β-AIB and/or ψ-Urd decreased after a transient rise.