Differences between graft product and donor side effects following bone marrow or stem cell donation

We report graft product stem cell yields and donor safety results of a randomized multicenter study comparing allogeneic peripheral blood stem cell (PBSC) PBSC transplantation with BM transplantation. Matched HLA-identical sibling donors (n = 329) were randomized to filgrastim-mobilized PBSC or bone marrow (BM) donation groups. Median yields per kg recipient weight of CD34⁺ cells, T cells, and natural killer (NK) cells, respectively, were approximately two-fold, eight-fold, and greater than eight-fold in the PBSC group than in the BM group (CD34⁺ cells, 5.8 × 10⁶/kg vs 2.7 × 10⁶/kg; T cells, 300.1 × 10⁶/kg vs 35.7 × 10⁶/kg; NK cells, 28.2 × 10⁶/kg vs 3.6 × 10⁶ /kg; P<0.001 for each). In connection with the cell collection procedures, PBSC donors spent a shorter median time in hospital than BM donors (0 vs 2 days; median difference -2 days, 95% CI -2 to 2) and had fewer median days of restricted activity (2 vs 6 days; median difference -3 days, 95% CI -4 to 2). Overall, 65% of PBSC donors and 57% of BM donors reported at least one adverse event (AE), most of which were transient, mild-moderate in severity, and without clinical sequelae. PBSC donors experienced predominantly filgrastim-related AEs, while BM donors experienced predominantly harvest-related AEs.