Cytogenetic analysis of hemopoietic peripheral blood cells collected by leukapheresis after intensive chemotherapy in advanced phase Philadelphia-positive chronic myelogenous leukemia

Peripheral hemopoietic blood cells previously collected by leukapheresis were reinfused in advanced phase Philadelphia (Ph)-positive chronic myelogenous leukemic patients to promote the recovery of bone marrow function after intensive radiochemotherapy. Cytogenetlc analysis was performed on these cells, Induced to proliferate and to be mobilized by a first administration of marrow toxic drugs and collected when the white blood cell count was very low. In five patients only Ph-negative apparently normal cells were found. In five cases different proportions of Ph+/Ph- cells were observed and in the remaining five cases only Ph+ cells were present. Chromosomal abnormalities other than Ph, not detected in the cytogenetic analysis performed on bone marrow cells before chemotherapy treatment, were found in five cases. These findings confirm that Ph- cells can persist in the marrow of Ph+ patients in the advanced phase of disease and Indicate that a high percentage of leukemic cells retain karyotype evolution not detectable using standard drawing and culture techniques.