The Use of Hematopoietic Growth Factors to Prevent Infectious Complications

Receptors for a variety of cytokines, including c-kit ligand, nterleukin-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF) and thrombopoietin are expressed on acute myeloid leukemia (AML) cells at physiological densities in most patients.(2) Th se receptors are of high affinity. When the ligands are added to cultures of AML cells, induction of metabolic and cell cycle activation appears. In some cases AML cells may mature towards terminally differentiated cells in response to cytokine stimulation. When AML cells stimulated with hematopoietic growth factors are subjected to chemotherapy in vitro, cell killing may be considerably enhanced.(1) These observations have been a reason for applying hematopoietic growth factors in the treatment of patients with AML. Thus, hematopoietic growth factors have been applied not only to accelerate hematopoietic regeneration following chemotherapy or hematopoietic stem cell transplantation to reduce morbidity and mortality, they have also been applied to prime AML cells for chemotherapy and to enhance the antileukemic efficacy of treatment. In selected conditions hematopoietic growth factors might also be applied to induce terminal maturation in leukemic blasts and overcome the maturation arrest. This may result in the extinction of the leukemic cell clone