Autologous Transplantation with Peripheral Blood Stem Cells in Children and Young Adults After Myeloablative Treatment: Nonrandomized Comparison Between GM-CSF and G-CSF for Mobilization

Recombinant human granulocyte-monocyte colony-stimulating factor (rhGM-CSF) was compared with recombinant granulocyte colony-stimulating factor (rhG-CSF) in 34 patients for mobilization of peripheral blood stem cells (PBSC) and for posttransplantation use. Peripheral blood stem cell mobilization was initiated by a single 1 h infusion of cyclophosphamide (4 g/m²) in all patients, followed by either a continuous infusion of rhGM-CSF (250 μg/m²/day) in 17 patients (group A) or a daily subcutaneous injection of rhG-CSF (10 μg/kg/day) in 17 patients (group B). PBSC were collected using a Fenwal CS 3000 continuous flow blood cell separator in one to three sessions. All patients suffered from various childhood malignancies. No difference in the number of collected cells among both groups was found. A mean of 2.7 x 10⁸/kg mononuclear cells (MNC) and of 7.9 x 10⁴/kg CFU-GM (colony-forming unit-granulocyte-macrophage) were collected in group A. In group B, 2.3 x 10⁸/kg MNC and 11.8 x 10⁴/kg CFU-GM were collected. In 33 patients, PBSC were reinfused after myeloablative therapy. Patients of group A (n = 17) were treated with rhGM-CSF (250 μg/m²/day) starting day +1, and patients in group B (n = 16) were treated with rhG-CSF (10 μg/kg/day) i.v. All patients showed a rapid and complete hematopoietic recovery without significant differences in both groups. Time to achieve 0.5 x 10⁹/L granulocytes was 10.9 days in group A and 11 days in group B. The median day to achieve platelet independence (i.e., platelet count > 20,000/μL) was 18 in group A and 17 in group B. No severe side effects and no death within 60 days occurred in either group.