Clinical collection and use of peripheral blood stem cells in pediatric patients

Peripheral blood stem cells have been used in lieu of marrow as autologous cellular support after marrow-ablative radio/chemotherapy. Autologous marrow support allows the use of higher, more effective doses of therapy. Peripheral blood stem cells (PBSC) offer the potential for this form of "transplant" in patients with marrow involved with disease. PBSC use also allows the avoidance of marrow harvest under general anesthesia. Previous reports of PBSC use have been limited to adults. This article describes peripheral blood stem cell collection in children, and documents the successful use of such cells in a 21/2-year-old boy and a 3-year-old girl with progressive stage IV neuroblastoma involving the marrow. Collections were performed using a Fenwal CS3000 blood cell processor primed with fresh frozen plasma and red cells, using a low flow rate to avoid citrate toxicity. The transplant was performed using collections that were negative or low in neuroblastoma cells (as detected by anti-neuron-specific enolase and antineuroblastoma monoclonal antibodies) after preparation with high-dose cyclophosphamide, etoposide, and cisplatin. Posttransplant recovery was uneventful, and engraftment was comparable to that in 4 patients treated with a similar preparative regimen followed by infusion of autologous marrow. Using careful technique, PBSC support in lieu of marrow may be a viable treatment modality in pediatric neuroblastoma or other solid tumors, particularly when the marrow is involved with disease.