[High-dose chemoradiotherapy combined with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) followed by autologous peripheral blood stem cell transplantation (PBSCT) in a case of refractory acute myelogenous leukemia (AML)].

Recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) stimulates the growth of myeloid leukemic cells and increases their susceptibility to cell-cycle specific agents. We treated a patient with acute myelogenous leukemia (AML) in a state of second resistant relapse, with high-dose chemoradiotherapy combined with rhGM-CSF (total body irradiation: TBI 3Gy x 4, on days -8 & -7; cytosine arabinoside: Ara-C 3g/m2, iv, q12h, on days -5-2; rhGM-CSF 250 micrograms/m2/day, cont.iv, on days -5-2) followed by autologous peripheral blood stem cell transplantation (PBSCT). In this case, rhGM-CSF enhanced the proliferation of leukemic cells in vitro. The test dose of rhGM-CSF (84 micrograms/m2 over 8 hours) also promoted leukemic cell proliferation in vivo, resulting in an increase in the percentage of leukemic cells in the peripheral blood and reappearance of chromosomal aberrations in the bone marrow. The toxicity of rhGM-CSF-combined conditioning regimen included fever and mild liver damage. The patient achieved a complete remission lasting for 2 months, then relapsed. The rhGM-CSF-combined conditioning regimen was tolerated by this patient, but further studies will be required to confirm not only its safety but also its effectiveness in the treatment of refractory AML.