De novo synthesis of purine nucleotides and metabolic availability of phosphoribosylpyrophosphate in leukemic leukocytes.

Among normal peripheral blood leukocytes, lymphocytes were found to contain most of the de novo purine synthesizing capacity. The rate of purine synthesis de novo was accelerated in leukocytes from patients with acute and chronic myelocytic leukemias, chronic monocytic leukemia, myelofibrosis and plasma cell leukemia, but was normal in most patients with chronic lymphocytic leukemia. The rate of de novo purine synthesis exhibited positive correlation with the percentage of immature cells in the leukocyte population. The metabolic availability of phosphoribosylpyrophosphate (PRPP) exhibited positive correlation with the state of de novo purine synthesis. These finding suggest that the accelerated rate of de novo purine synthesis and the increased metabolic availability of PRPP are characteristic properties of the immature leukemic granulocyte.