Safe and Efficient Peripheral Blood Stem Cell Collection in the Smallest of Children

: To clarify the factors that may affect the peripheral blood stem cell (PBSC) collection in children weighing ≤ 15 kg, a consecutive registry of 109 leukapheresis procedures was analyzed. Collections were performed on a COBE Spectra separator. In 65.1% of the procedures, the peripheral vein, together with a central catheter inserted routinely at diagnosis, or 2 peripheral veins were used to access/return. For 84.4% of the procedures, the extracorporeal line was primed with red blood cells. The median granulocyte-macrophage colony forming unit (CFU-GM) number derived from 1 patient's blood volume processed was 13.8 times 104/kg. Six times, a collection series failed, al ways in children treated for ≥ 26 weeks and 4 of those times in children weighing ≤ 11 kg. The patient's age, diagnosis, duration of preleukapheresis treatment, and mobilization regimens did not significantly affect the collection yield. Twenty-four transplantations were performed. The median times to neutrophils > 0.5× 109/L and platelets > 20 × 109/L were 13 and 20 days, respectively. We conclude that even in very small children, leukapheresis can be performed safely, allowing adequate PBSC collection for transplantation and/or in vitro manipulations.