Autologous peripheral blood stem cells (PBSC) are now routinely used as haematopoietic support after high-dose chemotherapy even in small children with various malignancies. Harvesting PBSC does not involve the risk of general anaesthesia or multiple invasive marrow aspirations and the use of PBSC results in a rapid and durable trilineage haematopoietic recovery after myeloablative chemotherapy. The authors present their experience with PBSC harvests in children (n = 33) with malignancies between January 1998 and April 2001. Patients, aged 1.8 - 11.6 years, with a median weight of 17 kg, were mobilized using either a combination of chemotherapy and G-CSF (granulocyte colony-stimulating factor) or G-CSF alone. PBSC harvest were performed using a COBE Spectra cell separator and started when CD34+ cell blood count after nadir reached at least 5x106/l in heavily pretreated children and 15x106/l in others. The extracorporeal line was primed with irradiated red blood cells and heparin as an anticoagulant therapy was used instead of citrate solution in most of patients with a weight < 18 kg. A total of 104 aphereses was performed with a median of 3 aphereses (1 - 6) per patient. A combination of permanent tunelised catheter and peripheral catheter was the most frequently used venous access (n = 24). A median of 3.5 total blood volumes 2.4 - 5.2) was processed during one leukapheresis with a median inlet flow of 25 ml/min (19 - 40) and 1.4 (0.5 - 2.4) ml/kg/min. A median of 7.8x106 CD34+ cells/kg (1.3 - 108.9), and 118.9x104 CFU-GM/kg (18.4 - 525.9) were collected. No hypotensive, hypothermic or bleeding complication nor signs of complication due to citrate toxicity were observed and the overall tolerance was very good. Authors conclude that leukaphereses using COBE Spectra could be safely performed even in very small children.

        Key words: PBSC, mobilisation, high-dose chemotherapy, leukapheresis