Background : The selective depletion of erythrocytes from aspirated bone marrow is
one of the important procedure for transplantation of ABO-incompatible or autologous
bone marrow. Therefore many trials to deplet erythrocytes from aspirated bone marrow
have been done. Especially, automated processing of aspirated bone marrow has been
known as one of the ideal methods with the benefit of no risk of contamination and
high efficacy to remove erythrocytes with a minimal loss of stem cells. And so, we
tried to deplet erythrocytes from large volumes of bone marrow with a automated
method using a Spectra without employing density gradient materials.
Methods : We compared the volume of bone marrow, hematocrit, mononuclear
cell(MNQ counts, CFU-GM colony counts, and CD34) cell counts before and after
processing with a Spectra at 10 samples of bone marrow aspirated from posterior
superior iliad crest. Among them, 8 samples were from healthy bone marrow donors at
ABO-incompatible allogeneic transplantation and 2 samples were from patients
underwent autologous peripheral stem cell transplantation. And the clinical findings of 8
patients who were transplantated with processed bone marrow were reviewed for the
evaluation of acute side reactions after transplantation with processed bone marrow,
neutrophil recovery, platelet recovery, and bone marrow engraftment.
Results :
1) Volume and hematocrit: After processing, the median bone marrow volume was
decreased from 1,600m1 to 173mL, and the median hematocrit was decreased from 42.5%
to 2.1%.
2) MNC counts: After processing, median MNC counts were decreased from 1.7×
10⁸ to 1.2×10⁸/kg. So, the recovery rate of MNC was 70%.
3) CFU-GM colony counts: After processing, median CFU-GM colony counts were
decreased from 1.7×10 4 to 1.3×10 4 /kg. So, the recovery rate
of CFU-GM was 76%.
4) CD34+cell counts: After processing, median CD34+ cell
counts were decreased from 1.6×10 6 to 1.2×106/㎏. So, the
recovery rate of CD34+ cell was 75%.
5) Clinical findings: We could not find an) acute side reactions after transplantation
with processed bone marrow, and confirm bone marrow engraftment in all patients with
bone marrow biopsy which was done at day 21 after bone marrow transplantation.
Median neutrophil recovery( > 500/μL) and platelet recovery(>20,000/μL) days were 18
and 24 days, respectively.
Conclusion: These data suggested that automated bone marrow processing with a
Spectra was practically applicapable at bone marrow transplantation to deplet selectively
erythrocytes from aspirated bone marrow.

Keywords: Bone marrow transplantation, Erythrocyte depletion,
Automated processing