EFFECTS OF GLYCOSYLATED AND NONGLYCOSYLATED G-CSFS, ALONE AND IN COMBINATION WITH OTHER CYTOKINES, ON THE GROWTH OF HUMAN PROGENITOR CELLS

Two recombinant human granulocyte colony-stimulating factors (rHu G-CS F) are clinically available, a glycosylated (lenograstim) and a nongly cosylated form (filgrastim). Since there is accumulating evidence that glycosylation plays a role in the in vitro activity of the G-CSF mole cule, we compared the biological potency of lenograstim and filgrastim on human hematopoietic progenitor cells by colony assay in semisolid medium and ex vivo expansion experiments. Leukapheretic products witho ut further processing and CD34-positive purified cells were used as so urce of human progenitors. Lenograstim demonstrated greater capacity, to stimulate the colony growth of both, purified and CD34+ peripheral blood cells. This effect, which is evident especially at low doses of growth factor, seems not to be mediated by accessory cells. Whether th ese observations may have clinical relevance is still to be clearly as sessed and further investigations are needed.