Isolation and characterization of the cd34+hematopoietic progenitor cells from the peripheral blood of patients with chronic myeloid leukemia

Abstract

A modified version of the original reported panning technique was used to separate CD34⁺ cells from the peripheral blood of patients with chronic myeloid leukemia (CML). In I3 out of 23 separations, populations of cells were obtained in which CD34⁺ cells constituted > 50% of the cells present. The best recovery and enrichment of the CD34⁺ cells was achieved when cells were obtained from patients in the accelerated phase of CML, when the cells were processed on the same day they were obtained from patients, and when adherence to soybean agglutinin flasks was used as a pre-enrichment step. In suspension culture, the CD34⁺ cells were capable of extensive proliferation and differentiation. In semisolid culture, the number of colony-forming units (CFUs) directly correlated with CD34 positivity. The number of clonogenic cells/CD34* cells was highest at the time of initial diagnosis of CML, fell during the chronic phase (CP) of the disease, and rose at the time of disease acceleration. This observation suggests that therapy during the CP of the disease produces a greater reduction in clonogenic cells than in the number of CD34⁺ cells. This effect disappears at the time of disease acceleration, presumably because of the development of drug resistance in the clonogenic cells.