FLOW CYTOMETRIC ANALYSIS OF CELLULAR DNA IN HUMAN ACUTE NON-LYMPHATIC LEUKEMIAS AND DYSMYELOPOIETIC SYNDROMES

The proliferation patterns of bone marrow cells from 16 cases of acute nonlymphatic leukemia (ANLL) and 13 of dysmyelopoietic syndromes were analyzed with DNA-flow cytometry. In order to reduce the contamination by nonproliferating peripheral blood cells, all aspirates were submitted to a density centrifugation step. DNA content measurements were performed with a PHYWEICP 22 flow system apparatus. The distribution of cells in te cell cycle phases was calculated by means of an automated fitting procedure. No significant difference between the cell cycle distribution in ANLL and dysmyelopoietic syndromes was detectable. No relationship was observed between the size of the S phase compartment and the percentage of blasts in the original samples. Aspirates from ANLL were also cultured in vitro in liquid phase on dialysis membranes. A clear relationship was observed between the size of the phase compartment and in vitro cell growth since, with the exception of one case, all samples with less than 11% cells in S phase failed to proliferate in vitro. The proliferation profile of ANLL cells after 10 days in culture was similar to that of the original samples.