[Autologous peripheral blood stem cells mobilization with etoposide plus rhG-CSF versus cyclophosphamide plus rhG-CSF].

BACKGROUND & OBJECTIVE: It is important to get high quality autologous peripheral blood stem cell (APBSC) for successful peripheral blood stem cell transplantation. Cyclophosphamide (CTX) plus recombined human granulocyte colony-stimulating factor (rhG-CSF) is standard regimen for APBSC mobilization. Etoposide plus rhG-CSF is another regimen for mobilization in recent years. The purpose of this study was to observe and compare the effects of these two regimens in APBSC mobilization for the patients with malignant lymphoma and germ cell tumors.

METHODS: Fifty-two patients were divided into two groups according to the regimen of mobilization. In CTX group, 26 patients were injected CTX 3.5 g/m(2) intravenously. The other 26 patients in VP-16 group, VP-16 1000 mg/m(2) or 1500 mg/m(2) were given intravenously at random. All patients received rhG-CSF once daily as subcutaneous injection at the dose of 5 microg x kg(-1) x day(-1) from the day of the nadir of white blood cell (WBC) till the day before the last APBSC harvest in both groups. APBSC harvest was performed daily when WBC recovered more than 2.5x10(9)/L in CTX group and 5.0x10(9)/L in VP-16 group. APBSC harvest finished when accumulated mononuclear cells (MNCs) were more than 5x10(8)/kg or CD34(+) cells were more than 2x10(6)/kg. Collected APBSC was infused following condition regimen. Blood parameters, account of harvested cells, the time of hematopoietic reconstitute, and adverse effects were compared between two groups.

RESULTS: Following administration of CTX or VP-16, the nadirs of WBC and PLT in CTX group appeared significantly earlier than that in VP-16 group. The doses and times of rhG-CSF administration were not significantly different between the two groups. The start was later and the times of APBSC apheresis were less significantly in VP-16 group. The processed blood volume in single apheresis was more in VP-16 group. Speed and duration of single apheresis were similar in the two groups. Total MNCs were similar in the two groups, but the numbers of MNCs and CD34(+) cells collected in the first harvest and total number of CD34(+) cells collected were significantly more in VP-16 group. With equal quantity infusion of MNCs and CD34(+) cells infusion, hematopoietic reconstitution was achieved in both groups and the time of reconstitution was similar. Nausea and vomiting were more frequent in CTX group. Obvious PLT decrease was observed in VP-16 group. Other adverse effects were similar.

CONCLUSION: CTX or VP-16 plus rhG-CSF both were safe and effective regimens for APBSC mobilization. More CD34(+) cells can be harvested by mobilization with VP-16 plus rhG-CSF than mobilization with CTX plus rhG-CSF. And the APBSC mobilized with VP-16 plus rhG-CSF can assure successful hematopoietic reconstitution.