COLLECTION AND TRANSPLANTATION OF PERIPHERAL BLOOD PROGENITOR CELLS MOBILIzED BY G‐CSF ALONE IN CHILDREN WITH MALIGNANCIES

Results of collection and transplantation of peripheral blood progenitor cells (PBPC) mobilized by G‐CSF in 31 children with different malignancies were analysed. A total of 43 aphereses were performed, following administration of granulocyte colony‐stimulating factor (G‐CSF), using a continuous flow blood cell separator (Cobe Spectra) through a central venous catheter. For patients weighing ≤25 kg the extracorporeal line was primed with red blood cells. The mean blood flow rate was 33.2ml/min (range 12–56ml/min). The mean number of mononuclear cells (MNC), granulocyte‐macrophage colony‐forming units (CFU‐GM) and CD34+ cells collected were 7.22×108/kg body weight (b.w.), 15.9×104/kg and 5.44×106/kg respectively. The morbidity related to PBPC collection was low and the mean apheresis time was 302.7min (range 115–492). The volume of processed blood for apheresis (per kilogram body weight) ranged from 117 to 539.6 (mean 309.13ml/kg). 20 patients required only one apheresis to collect the minimum requirement of 5–7×108/kg of MNC. All patients subsequently underwent autografting with PBPC after myeloablative therapy. Days to achieve an absolute count of neutrophils (ANC) <0.5×109/l and a platelet count of 20×1092/l without platelet support were 9.5 and 18, respectively. The number of CD34+ cells infused correlated highly with engraftment kinetics. The extramedullary toxicity was low and manageable.