Imbalance in the ribonucleotide pools of lymphoid cells from acute lymphoblastic leukemia patients

The intracellular purine and pyrimidine ribonucleotide concentrations were determined in the lymphoid cells from peripheral blood and/or bone-marrow of 29 patients with acute lymphoblastic leukemia (ALL), as well as in the mononuclear cells from peripheral blood of 12 patients with ALL in remission. The lymphoid cells of ALL patients showed an imbalance in the nucleotide pool compared with normal lymphocytes, whereas the nucleotide pool of mononuclear cells from patients with ALL in remission had normal values. The imbalance in the lymphoid cells from ALL patients involved decreased ratios of purine:pyrimidine, adenine:guanine and uracil:cytosine nucleotides, and an increased amount, together with a changed composition, of the UDP sugars. When compared with tonsil-derived B lymphocytes and thymocytes, ALL lymphoid cells have an increased amount (absolute and relative) and a change composition of the UDP sugars. Significant differences were found between the mean values for the immunologically defined subgroups of ALL and between the mean values for patients with a high or a low percentage of blast cells. However, individual patients cannot be classified according to their nucleotide pattern, because of the overlapping ranges. The results of this study may be useful for the design of new therapeutic regimens.