STEM-CELL MOBILIZATION, COLLECTION AND TRANSPLANTATION IN PATIENTS WITH PEDIATRIC TUMORS

Peripheral stem cells (PBSC) were collected in 13 patients with various malignancies. All patients had disseminated disease at the time of diagnosis. The age of the patients ranged from 2.1 to 21 years and the body weight from 10.7 to 65 kg. In order to mobilize stem cells from the bone marrow into the peripheral blood, 13 patients were treated with a single dose of cyctophosphamide (4 g/m2) followed by the continuous infusion of Granulocyte-Macrophage Colony-stimulating Factor (250 mug/m2/day). PBSC were collected during the haematopoietic recovery phase. The number of apheresis ranged from 1 to 3, the number of collected mononuclear cells was 2.8 +/- 1.0 x 10(4)/kg body weight (range 1.8 to 6.0 x 10(8)/kg, n = 13), the number of collected CFU-GM was 17.6 +/- 19.2 x 10(4)/kg (range 3.1 to 62.4 X 10(4) /kg, n = 12) and the number of collected CD34+ progenitor cells was 8.8 +/- 7.4 x 10(6)/kg (n = 9). Ten patients were autografted with the PBSC's. In all autografted patients, a rapid reconstitution occurred within 14.6 +/- 6.6 days. These data show that stem cells can be mobilized to the peripheral blood following treatment of the patients with cyclophosphamide and GM-CSF. Stem cells may be collected and preserved successfully for autotransplantation.