Outcomes of autologous blood collection prior to bone marrow harvest for matched unrelated donors.

Abstract

e18535 Background: Autologous (auto) blood collection prior to bone marrow (BM) harvest is a common procedure however there is little data to say whether this is beneficial. Methods: This is a retrospective study evaluating the efficacy of pre-op auto blood collection in healthy unrelated donors who underwent BM harvesting at our institution between 9/2009 and 8/2017. Unrelated donors aged 18 or older who underwent their first BM harvest were included. Comparisons were made using two sample t-tests. Results: Among the 73 BM donors, 54 (74%) underwent auto blood collection resulting in 78 units collected. The cohorts with and without auto blood collected were similar in age and gender (mean age 31.0 vs 30.2; female 59% vs 41%). Those with auto blood collected donated larger volumes of marrow (mean 1395 mL vs 799 mL, p = 0.0002). Baseline hemoglobin (Hb) was similar between the cohorts (mean 14.1 g/dL vs 14.0 g/dL, p = 0.87). However, those with auto blood collected had lower pre-harvest (mean 13.1 g/dL vs 13.8 g/dL, p = 0.0430) and post-harvest Hb (mean 10.0 g/dL vs 11.3 g/dL, p = 0.0120). Of the 78 auto blood units collected, 45 units (58%) were used with 92% of women and 56% of men receiving their auto blood post-op. 33 (42%) auto blood units were discarded. Donors who were given back their auto blood were more likely to be female and have lower pre- and post-harvest Hb. Reasons for auto blood transfusion were blood availability (31%), donor post-op symptoms (i.e. hypotension, dizziness, syncope, and bleeding; 23%), intra-operative transient hypotension (26%), post-op anemia (11%) and patient request (9%). None of the patients who were transfused auto blood, or donors without auto blood collection, required allogeneic blood. Conclusions: Based on our results, collection of auto blood prior to bone marrow harvest leads to lower pre-op Hb and increases the likelihood of post-op blood transfusion. In addition, availability of auto blood can lead to over transfusion which may be detrimental to donor health. Although there may be a subset of donors who might benefit, routine auto blood collection prior to bone marrow harvesting is unnecessary and can be potentially hazardous to donors.