The 48th Annual Meeting of the European Society for Blood and Marrow Transplantation: Physicians – Poster Session (P001 – P578)

Background: Bone marrow donation is a procedure that takes place in a hospital operating room. In many hospitals, autologous red cell units are collected from donor before the harvest and reinfused immediately after the donation to reduce the risk of anemia. The blood donation stimulates hematopoiesis, so it's possible that autotransfusion has an impact on number of collected cells. The aim of this study is to assess whether blood donation before the harvest has an impact on the total number of nucleated cells in the product. Methods: Study design: Most of the donors undergo preharvest autologous blood collection. The procedure was not carried out if the weight difference is greater than 30kg in favor of the donor. Until March 2020, due to COVID-19, routine blood donations for autotransfusion were suspended. This situation gave an opportunity to assess, if the donation of blood has an impact on the efficiency of BM collection and hemoglobin level in donors' blood after harvest. Bone marrow was aspirated under general anesthesia, from both pelvic bones. According to the local protocol the volume of marrow and WBC was measured during donation;if the total number of nucleated cells was sufficient, the donation was finished. The collection was also completed, if the total volume of BM reached 15 ml per kg of donor's body weight. Laboratory analyses: The blood samples for morphology analyses were taken in the day of qualification, one day before and one day after harvest. The samples of BM were taken during donation to measure number of lymphocytes. Statistics: TheMann-Whitney U-test was used to determine the significance between the cohorts. Differences with p values <0.05 were considered as statistically significant. Results: Between March and October 2020, 15 BM donations from 15 healthy donors (10 men and 5 women, median age: 35 years, range 20-49 years) were performed;these donors were not referred for autotransfusion. The control group consisted of 34 donors, who underwent harvest between January 2019 and March 2020 (23 men and 11 women, median age 25 years, range 18-41 years). Total volume collected BM was comparable in both groups (median: 1182 ml in first vs 1277 ml in control group). The level of hemoglobin on the day of qualification was similar in both group: median 15.2 g/dL for donors who had blood donation;and 15.4 g/dL, for donors not referred to autotransfusion. One day before harvest, the first group had statistically lower level of hemoglobin (median 14.1 g/dL vs 14.8 g/dL, p < 0.001), however one day after BM collection both groups were comparable (median 11.1 g/dL vs 11.5 g/dL). Total number of nucleated cells in the product was comparable in both groups: median 204 × 108 in donors referred for autotransfusion vs 219 × 108 in control group. Conclusions: Autologous blood transfusion had no impact on Hb levels in blood after BM donation and had no impact on the efficiency of BM harvest. This does not support the routine use of autologous blood transfusion for unrelated BM donors.