[Impulse cytophotometry studies of bone marrow and blood cells in children with acute lymphoblastic leukemia (ALL). 2. Lymphatic cells in blood].

The DNA-content of mononuclear cells of the peripheral blood of infantile and juvenile ALL patients was investigated using Pulse Cytophotometry. The fraction of cells in S- and G2 + M-phase is significantly increased in comparison with samples of healthy probands. The fraction of DNA-synthesising cells (S-phase) of both peripheral blood (mononuclear cells) and bone marrow of leukemia patients cannot be significantly distinguished by mathematical methods. On the other hand, the fraction of cells in later phases of cell cycle (G2 + M-phase) is significant enhanced in the bone marrow in comparison with the peripheral blood. A high correlation was found between the number of leukocytes and fraction of G2 + M-phase cells in the peripheral blood of SR- and MR-patients. No correlation was found between the number of leukocytes and S-phase-fraction. The occurrence of aneuploid cell populations in the mononuclear fraction of peripheral blood in the acute state of ALL could be of importance for prognosis and regime of therapy.