The parameters of cellular proliferation in acute (immature-cell) leukemias.

In 20 patients with acute leukemia the 3H-thymidine labelling index and the mitotic index were determined in the population of leukemic blast cells and the degree of bone marrow infiltration was evaluated. Determinations were carried out in acute stage of the disease and in 4 cases additionally during improvement or remission and then during subsequent exacerbations. In the acute phase of the disease both indices were low in comparison with the indices obtained in normal granulocytopoiesis. In acute leukemia in 15 cases the bone marrow contained high or moderate number of cells, while in 5 remaining cases it was low. The 3H-thymidine labelling index and the mitotic index were lower in acute period of the disease in patients with bone marrow infiltration as compared with patients with hypoplastic bone marrow. During improvement both proliferation indices increased.