Clinical significance of autologous blood transfusions in bone marrow harvest from unrelated donors

In the Japan Marrow Donor Program (JMDP), autologous blood is collected from most unrelated bone marrow (BM) donors. We retrospectively evaluated 5772 donors who underwent BM harvest between 2010 and 2015 through the JMDP. Autologous blood was collected in 96.8% of the donors; the wastage rate was 0.6%. Allogeneic blood transfusion was not required. The mean hemoglobin (Hb) levels were 12.1 g/dL after the BM harvest (mean 891 mL) together with autologous blood transfusion (mean 596 mL). Propensity-score matching was used to adjust the backgrounds. Among donors with harvested BM of 100–400 mL, autologous blood transfusion had no impact on Hb levels or complications after BM harvest. Among donors with harvested BM of > 400 mL, more autologous blood transfusion followed by a bleeding volume of ≤ 100 mL did not confer clinical benefit to donors compared with less autologous blood transfusion followed by a bleeding volume of > 300 mL. The findings of the present study suggest that autologous blood transfusion to BM donors is excessive in terms of Hb changes and post-harvest outcomes.