RECOMBINANT HUMAN GRANULOCYTE-COLONY-STIMULATING FACTOR IN COMBINATION WITH CONTINUOUS-INFUSION OF CYTOSINE-ARABINOSIDE FOR THE TREATMENT OF REFRACTORY ACUTE MYELOGENOUS LEUKEMIA

Because recombinant human granulocyte colony-stimulating factor (G-CSF ) has been reported to increase the sensitivity of acute myelogenous l eukemia (AML) blast cells to cytosine arabinoside (Ara-C) in vitro, we treated a patient with refractory AML with an Ara-C-based regimen in combination with G-CSF (G-CSF/Ara-C therapy). G-CSF (50 mug/m2/day, su bcutaneous injection) was administered simultaneously with a continuou s intravenous infusion of Ara-C (70 mg/m2/day). Complete remission was achieved, however, severe neutropenia, documented infection, stomatit is, and diarrhea were observed. In vitro studies using H-3-thymidine u ptake and dual parameter flow-cytometric analysis of DNA and prolifera ting cell nuclear antigen showed that leukemic blast cells in S phase were increased after incubation with G-CSF. G-CSF also enhanced expres sion of the transferrin receptor (CD71) on blast cells in vitro. These observations suggest that G-CSF/Ara-C therapy may be useful in the tr eatment of high-risk AML.