Flow cytometric detection of cytomegalovirus antigen in peripheral blood cells after bone marrow transplantation

We report 13 normal peripheral blood stem cell (PBSC) donors who had a second PBSC collection for allogeneic transplantation performed after the first. The median interval between the first and second collection was 5 months. Mobilization was achieved with filgrastim (12 μg/kg/d). No significant difference was found in the median pre-apheresis leucocyte count (×10⁹/l) between the two donations (40.2 v 38.5; P  = 0.91). The median apheresis yield (×10⁶ CD34⁺ cells/litre blood processed, first apheresis) was also similar (28 v 27.3; P  = 0.91). Filgrastim-related adverse events were comparable. These data suggest that second PBSC collections are feasible, similarly tolerated and provide comparable apheresis yields.