High-dose melphalan followed by autograft employing non-cryopreserved peripheral blood progenitor cells in children.

Abstract

High-dose chemotherapy followed by autologous bone marrow transplantation (ABMT) enables dose escalation in the treatment of childhood malignancies. Here we report our experience of using peripheral blood progenitor cells (PBPC) to restore haematopoiesis in five children using a simple cell mobilising regime and non-cryopreservation of the harvests. Cells were mobilised using cyclophosphamide and granulocyte colony stimulating factor. Each patient underwent only two leukaphereses, the product being stored before use at 4 degrees C. Successful autologous PBPC transplantation was achieved with melphalan conditioning chemotherapy and re-infusion of the total progenitor cell product. No colony stimulating factors were administered after transplantation. The median numbers of mononuclear cells collected per patient was 10.0 x 10(8)/kg (range 8.13-19.44) and CFU-GM 57.6 x 10(4)/kg (range 10.4-178.85). All patients subsequently engrafted with the median number of days to a neutrophil count > 0.5 x 10(9)/l being 11 (range 10-16), and to a platelet count > 50 x 10(9)/l being 14 (range 12-31). The median number of in-patient days was only 20 (range 19-30). The median demand for blood was 2 units (range 1-2), and platelets 4 units (range 2-28). Usage of systemic antimicrobials and intravenous feeding was also low. Using this simple strategy, collection and transplantation of autologous progenitor cells can be a straightforward procedure in children. It is possible that this could enable dose escalation in some poor prognosis paediatric tumours.