Effects of Hematopoietic Growth Factors on the Bone Marrow and Mobilized Peripheral Progenitors from the Same Person

Kwon, Ki Young

Abstract

BACKGROUND: Peripheral blood progenitor cell (PBPC) is now widely used as alternate source to bone marrow for transplantation. The objectives of this study are to compare the clonogenic potential of marrow and mobilized peripheral progenitors obtained from the same person. To examine the activity and effectiveness of G-CSF in different concentration, and to compare the influence of different peroid of exposure with growth factors, mononuclear cells from the bone marrow and peripheral blood were enriched in RPMI media containing different sets of growth factors for various durations. MATERIAL AND METHOD: Bone marrow cells were obtained from 5 lymphoma patients with normal marrow function. PBPCs mobilized by cyclophosphamide plus 10microgram/kg of G-CSF or daily 10microgram/kg of G-CSF alone for 4 days and harvested by leukapheresis with Cobe-Spectra apheresis unit. After Ficoll-Hypaque separation, viable 2x106 mononuclear cells were innoculated in RPMI media containing 10% autologous serum, and 6 sets of different combination of cytokines. Each set of media contains 100ng/mL of stem cell factor, 1,000U/mL of G-CSF, 5,000U/mL of G-CSF, 100ng/mL stem cell factor+1,000U/mL G-CSF, 100ng/mL stem cell factor+5,000U/mL G-CSF and control group which didn't add any growth factor. After 1, 7, 10 days of culture in liquid media, test for viability with trypan blue were done and 1x105 cells were seeded in methylcellulose media and were cultured in duplicate. After 14 days incubation, CFU-GM count were done under inverted microscopy.
RESULTS
CFU-GM were generally increased even in 1 day exposure with growth factors than control in both bone marrow and PBPC group. Prominent increase were noted in the combination of 2 cytokines. Seven and 10 days of exposure with growth factors, there showed similar findings but the bone marrow derived mononuclear cells had a tendency of peak level in 1 day exposure but the highest level of CFU-GM in PBPC group was noted in 7 days exposure with growth factors. Assessment of clonogenic activity of marrow and mobilized PBPC, both group yield similar number of CFU-GM.
CONCLUSION
These results indicated the bone marrow and PBPC can be enriched exvivo with G-CSF and stem cell factor. The degree of expansion of PBPC and marrow CFU-GM were significantly increased with combination of cytokines. Compare to their clonogenic potential of mononuclear cells from the bone marrow and peripheral blood failed to demonstrate any significant difference.