Peripheral Blood Progenitor Cell Collection in Low-Weight Infants (36 patients; 69 Large Volume Leukapheresis Procedures)

• Published in: Blood 2008-11, Vol.112 (11), p.4133-4133
• Main Authors: Chacim, Sergio Pereira, Roncon, Susana, Barbosa, Isabel, Pinto, Bernardo Bollen, Avila, Alcina, Ferreira, Sara, Leal, Helena, Machado, Sergio, Carvalhais, Alzira
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V112.11.4133.4133

Peripheral blood progenitor cells (PBPC) have increasingly become the preferred source of stem cells for autologous transplantation due to their easier accessibility, rapid engraftment and higher safety. The harvest of PBPC in paediatric patients assumes critical importance, particularly in low-weight infants, in whom optimizing the procedure allows the collection of sufficient number of cells, with a reduced number of leukapheresis. The published data of these low-weight patients are scarce, and very likely the accumulation of cases will contribute to optimize the procedure. In this single centre study we retrospectively analyzed data of 69 large volume leukapheresis (LVL) from 36 low weight (< 20Kg) paediatric patients between January 1998 and April 2008. Primary diagnosis included several malignancies: neuroblastomas (21 cases), meduloblastomas (4 cases), acute leukaemia (4 cases), retinoblastoma (2 cases) and other 5 cases with various solid tumours. All the LVL procedures underwent with a continuous flow blood separator (COBE Spectra) after priming the extracorporeal line with red blood cells and acid-citrate-dextrose (ACD) was used as the anticoagulant. Mean body weight was 15,78kg (ranging 9–19Kg), and a median age of 44 months (ranging 7–88 months). Blood withdrawn at a mean rate of 33,8 mL/min (standard deviation [SD] 8,0), through central vein catheters and using 4 volemias (one case with 3), lasting a mean 133,43 minutes/procedure (ranging 212–101 min). A mean of 4881,78 ml of blood was processed (ranging 2101–7327mL). Leukapheresis was performed on the fifth day of G-CSF stimulation in most of the procedures (66,7%), while 21 patients were submitted to stimulation for a longer period (18,8% with 6 days, 7,2% with 7 days and 4,3% with eight). The mean G-CSF dose used was 203,06 μg/d (ranging 105–400 μg/d). The mean number of CD34+ cells in peripherical blood, before leukapheresis, was 20,4 ×106 cells (ranging 1–216 ×106 cells), while the PBPC collection yielded 2,73 ×106 CD34+/Kg (ranging 0,1–28,94 ×106 CD34+/Kg). The majority of LVL procedures (53,6%) were initiated with a peripherical blood CD34+ count inferior to 15×106 cells. Only 33,3% of each LVL procedure harvest sufficient PBPC (> 2,5 ×106 CD34+/Kg), most of which from patients with peripherical blood CD34+ count superior to 15×106 cells (59,4%). There is a significant correlation between peripherical blood CD34+ count, before leukapheresis, and collected PBPC CD34+ (Pearson chi-square 1