Characterization of clonogenic cells in refractory anemia with excess of blasts (RAEB-CFU): Response to recombinant hematopoietic growth factors and maturation phenotypes (original) (raw)

Maturation of human acute myeloid leukaemia in vitro; the response to five recombinant haematopoietic factors in a serum-free system

British Journal of Haematology, 2008

Summary The abilities of human recombinant IL-3, GMCSF, G-CSF, M-CSF and Epo to induce maturation in human AML cells in vitro were investigated using cell specimens from 25 AML patients. The experiments were carried out under exactly defined serum-free culture conditions. In the absence of CSFs, monocytic and/or granulocytic maturation was detected in 14/25 cases. IL-3, GM-CSF, G-CSF and M-CSF elevated the proportions of monocyte/macrophages in 3/25, 2/25, 1/25 and 6/25 cases respectively, and increased the percentages of mature granulocytes in 2/25, 1/25, 1/25 and 0/25 cases, and if so only to a limited extent (values below 50%). The 3H-thymidine (3H-TdR) uptake studies revealed that IL-3, GM-CSF, G-CSF and M-CSF were efficient stimulators of DNA synthesis of AML cells in 19, 15, 13 and four of those cases, respectively. Thus, although the cells in most cases responded to CSFs by activation of DNA synthesis, they were unable to give rise to terminally differentiated stages. Provision of CSFs in combination was more frequently effective in enhancing maturation and also increased the magnitude of maturation response. Monocytic versus granulocytic maturation of AML cells after culture did not correlate with the FAB cytology nor with the type of CSF presented; but generally granulocytic maturation was an infrequent phenomenon. Epo stimulated erythroid differentiation and DNA synthesis only in the case of erythroleukaemia, but it had no effect on the cells of 10 other AML cases. Extrapolation of these in vitro findings would suggest that CSFs would have a limited therapeutic utility to induce AML cell maturation in vivo and that hazards of stimulating blast cell proliferation with these factors may be anticipated.

Both early and committed haemopoietic progenitors are more frequent in peripheral blood than in bone marrow during mobilization induced by high-dose chemotherapy + G-CSF

British Journal of Haematology, 1995

Summary. Haemopoietic growth factor administration following high-dose chemotherapy markedly amplifies progenitor cell pool in the peripheral blood (PB). Collection and reinfusion of these cells enable rapid haemopoietic recon-stitution following autograft. Less is known on engraftment potentiality of bone marrow (BM) cells taken under analogous conditions. To investigate this tissue, PB and BM were evaluated simultaneously during maximal mobilization in a series of 14 patients undergoing the HDS chemotherapy programme. A significantly higher growth of committed progenitors was found from PB rather than from BM (663 ± 123 v 267±40CFU-GM/105 MNC, respectively). Also, significantly more CFU-GM could be collected by a median of three leukaphereses, compared to those harvested from BM (158 ± 31 v 16 ± 4 ± 104 CFU-GM/kg, respectively). Most mobilized CFU-GM were phenotypically immature (CD15−); in addition, circulating cells included primitive progenitors, as assessed by LTC-IC assay, or by evaluation of non-proliferating pre-CFU-GM, selected by an anti-CD71 immunotoxin. The amount of pre-CFU-GM determined by both techniques was consistently higher in PB than in BM. Moreover, a direct correlation could be established between circulating CFU-GM and primitive precursors. Thus, during optimally induced mobilization, PB contains many more haemopoietic progenitors, of both committed and primitive stages, than does BM. Under such conditions, PB is probably the best source of material for graft purposes.