The Correlation between G-CSF Dosage and the Number of Collected CD34+ Cells in Pediatric Patients Undergoing Peripheral Blood Stem Cell Mobilization

ABSTRACT

BACKGROUND: In high risk malignancies of pediatric patients, many investigators have explored the use of stronger myeloablative regimens with autologous peripheral blood stem cell rescue such as the Tandem protocol. As the collection of peripheral blood stem cells in children have many risks, it is important to achieve the maximum number of CD34+ cells per leukapheresis. We analyzed the use of different doses of granulocyte-colony stimulating factor during a mobilization for an increased number of CD34+ cells. METHODS: A retrospective chart review was performed for 31 patients undergoing autologous peripheral blood stem cell mobilization. All patients had received specific chemotherapies. At the nadir, each patient was injected with 5 microgram/kg/day G-CSF. When the level of white blood cells reached more than 1,000/microliter, patients were divided according to the different dose of G-CSF that was given per day Group I, 5 microgram/kg, Group II, 10 microgram/kg, Group III, 15 microgram/kg. After 2~3 days, leukapheresis was performed, and then the number of CD34+ cells and other cells were counted. RESULTS: In group III, the number of collected CD34+ cells was 19.86+/-14.45x10(6)/kg and significantly higher than in the other two groups. Also, group III had significantly higher numbers of total nucleated cell, mononucleated cells, white blood cells, though the absolute neutrophil count compared with the other groups. There were no serious adverse effects associated with the higher G-CSF doses employed. CONCLUSION: At nadir, a pediatric patient received 5 microgram/kg G-CSF daily until the WBC count reached more than 1,000/ microliter. If the patient is injected with 15 microgram/kg/day of G-CSF, we can achieve a more sufficient CD34+ cell yield with one leukapheresis, safely.