Clinical applications of flow karyotyping in myelocytic leukemia by stimulation of different subpopulations of cells in blood or bone marrow samples

Examples are presented in which normal as well as abnormal chromosome distributions could be obtained from the same individual by means of bivariate flow karyotyping. Selective stimulation of T-lymphocytes obtained by E-rosetting from the blood of a patient with acute myelocytic leukemia resulted in a normal flow karyogram. The specific stimulation of myelocytic leukemia cells with granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin 3 (IL-3) yielded flow karyograms displaying the leukemia-associated chromosome abnormalities. The resulting flow karyograms could be used to discriminate between homolog differences, which appear normally in virtually every individual, and leukemia-associated chromosomal aberrations. In the case of a female chronic myelocytic leukemia patient who received bone marrow form an HLA-identical male donor, specific stimulation of various subsets of cells enabled to discriminate between leukemic host cells and non-leukemic donor cells. Both the leukemia-specific translocations and sex chromosomes were used as markers to analyse the flow karyograms obtained from the same sample.