Ex vivo expansion and characterisation of CD34(+) cells derived from chronic myeloid leukaemia bone marrow and peripheral blood, and from normal bonemarrow and mobilised peripheral blood

Ex vivo culture of CD34(+) has the potential to provide large numbers of ce lls for clinical use in autologous and allogeneic transplantation and for e xperimental research involving genetic manipulation We evaluated the ex viv o expansion of CD34(+) cells obtained from bone marrow (BM) and peripheral blood (PB) of untreated patients with chronic myeloid leukaemia (CML) in th e chronic phase and compared these results with those obtained from BM from normal volunteers (NBM) and peripheral blood after mobilising chemotherapy from patients with non-haematological disorders (MPB). Selected CD34(+) ce lls were stimulated with interleukin 1(beta), interleukin IL-3, interleukin IL-6 and stem cell factor. The proliferation observed in patients with CML was similar to that seen in normal donors. CD34(+) cells derived from pati ents with CML are more differentiated than their normal counterparts, as sh own by the coexpression of CD34 and CD33 antigens on day 0 (85.6% for CML-B M and 76.8% for CML-PB). The culture conditions allowed a significant expan sion of granulocyte-macrophage colony-forming units (CFU-GM) from NBM (33-f old increase) and MPB (22-fold increase), in contrast with CML-derived BM a nd PB CD34(+) cells (2.3-fold increase). These results indicate that the op timal time to harvest ex vivo expanded cells is dependent on a critical com promise between cell numbers and successful retention of their repopulating potential.