Quantitation by flow cytometry of anthracycline drug uptake by peripheral blood and bone marrow cells in human leukemias.

The inherent fluorescence of the anthracycline drugs can be combined with flow cytometry to obtain a convenient and rapid method for the quantitation of anthracycline drug uptake by human leukemic cells. A good correlation exists between the average cellular fluorescence intensity and the amount of drug associated with the cell as measured by extraction. Cellular incorporation of adriamycin and daunomycin was determined in peripheral blood and bone marrow cells of human leukemic patients after standardized in vitro exposures. Differences in uptake were found between the different cell types, with cells of lymphatic origin incorporating less of the drugs than nonlymphatic cells. Preliminary observations made in two patients with nonlymphatic leukemia showed a correlation between the in vitro uptake of adriamycin and the clinical response.