Sequential Changes in Stem Cell Markers in Peripheral Blood and Leukapheresis Samples after Injections of Recombinant Human Granulocyte Colony-stimulating Factor in Patients with Urogenital Malignant Solid Tumors: A Preliminary Study

Abstract

In order to evaluate the mobilization effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on peripheral blood stem cells (PBSCs), rhG-CSF was given to patients with urogenital malignancy before chemotherapy. Markers for the stem cells, such as colony forming unit-granulocyte/macrophage (CFU-GM) and burst forming unit-erythrocyte (BFU-E), were sequentially monitored in peripheral blood and leukapheresis samples. Five patients, including a 13-year-old boy, were given 5 micrograms/kg rhG-CSF subcutaneously: the pediatric case for four consecutive days and the adult cases for six consecutive days (53-72 years of age). None of the patients had received chemotherapy within the four weeks prior to the start of the rhG-CSF series. PBSC collections were performed on the fifth day in the pediatric case and on the fifth and seventh days in the adult cases. Progenitor cells were monitored by methyl-cellulose cell culture techniques. CFU-GM on day 5 of the rhG-CSF series in peripheral blood increased 14- to 53-fold compared with samples taken immediately before the series. CFU-GM in the leukapheresis products on day 5 was greatest (70 x 10(3)/kg) in the pediatric case and least (14 x 10(3)/kg) in the oldest patient's case. The totals of the CFU-GM collected by two phereses in the adult cases were 21-73 x 10(3)/kg and the totals of CD34 positive cells were 0.6 to 1.4 x 10(6)/kg. The data suggest rhG-CSF to induce sufficient PBSCs for bone marrow rescue into the peripheral blood without any preceding chemotherapy. The patient's age may, however, be a contributory factor in using this method.