Amino acid metabolism in patients with acute leukemia

It has been shown that the free phenylalanine and tyrosine levels in plasma of patients with acute leukemia are significantly higher than in normal patients. Tyrosine and tyrosine metabolites in the urine are apparently normal, and the hyperpigmentation that has been observed in patients receiving folic acid antagonists cannot be directly related to tyrosine excretion in the urine or to the elevated melanin precursors in the blood. Isoleucine values were higher in the plasma of leukemia patients than in normal individuals. Several leukemia patients showed unusually elevated valine and methionine values. Creatine and creatinine excretion were normal in patients with acute leukemia.