[The mechanism of cell proliferation in acute (immature-cell) leukemia]

In 40 patients with acute leukaemias the 3H-thymidine and mitosis indices were determined in the population of blast cells in bone marrow and the cellularity of bone marrow was determined. The studies were carried out in the first episode of the disease before treatment and in some patients (13) they were repeated during relapse after remission or improvement. The results showed that proliferative activity of blast cells was reduced in relation to precursors of normal granulopoiesis in all forms of acute leukaemia. Myeloblastic leukaemias showed a greater scater of values of both proliferation parameters in relation to lymphoblastic leukaemias. It was found, moreover, that in highly cellular bone marrow the proliferative activity of blast cell population was significantly lower than in patients with low bone marrow cellularity. On the ground of this observation the authors put forward the view that in acute leukaemias the intrinsic mechanism controlling the proliferation of cells is disturbed.