Impact of Autologous Blood Transfusion after Bone Marrow Harvest on Donor Health and Outcome

Abstract

Background Autologous (Auto) blood collection from healthy adult bone marrow (BM) donors is commonly performed before BM harvest to meet potential peri-operative transfusion needs and avoid necessity of allogeneic (Allo) blood exposure. Although Auto blood transfusion has been associated with advantages, it is not without risk. Bacterial contamination of blood product, misidentification of the blood unit and transfusion associated circulatory overload have been seen as commonly with Auto blood as with Allo blood transfusion. In addition, many collected units remain unused and discarded leading to wastage of resources. This study examines donor and collection variables associated with Auto blood transfusion with an aim to evaluate the impact of Auto blood transfusion on donor health after BM harvest. Method The primary outcome was incidence of highest toxicity level across selected body symptoms associated with BM harvest. The secondary outcomes were incidence of skeletal pain at 2 days, 1 and 6 months after harvest. The population studied was domestic unrelated BM donors reported to the NMDP/CIBMTR between 2006 and 2017. The NMDP donor form does not capture whether the donor had storage of Auto blood. It only asks whether the donor received blood transfusion. Thus, analysis was focused on whether the donor received Auto blood transfusion. Donors who received Allo blood were excluded (n=25). Logistic regression was used to compare pain and toxicities of those receiving and not receiving Auto units, after adjusting for donor characteristics. Stepwise variable selection with significance level of 0.01 was used. Results Examination of 7024 BM donors revealed 60% (n=4211) received at least 1 unit of Auto blood. The donors who had Auto blood tended to be male, younger, overweight, had lower hemoglobin pre-harvest, received longer duration of anesthesia and underwent higher volume BM harvest (Table 1). Before 2016, donor centers were advised by NMDP to collect 1 or more Auto blood units based on expected BM volume collection. In 2016 Auto blood collection was made discretionary as a center choice resulting in a significant decline in Auto blood transfusion in more recent years. Based on the multivariate analysis, there was no significant difference in grade 2 to 4 highest toxicity level 2 days after harvest between cohorts with or without Auto blood transfusion. Donors who received Auto blood were more likely to experience grade 2 to 4 skeletal pain 2 days post BM donation. However, grade 2 to 4 skeletal pain at 1 and 6 months after BM harvest were comparable between the two cohorts (Table 2). Time to recovery of symptoms was significantly longer in transfusion cohort (Figure 1). Conclusion Based on our data there is no evidence of clinical benefit in donors receiving Auto blood transfusion compared to those who do not. Thus, Auto blood transfusion may not be justified as a routine practice in healthy BM donors.