Ks. Tsang et al., Processing of major ABO-incompatible bone marrow for transplantation by using dextran sedimentation, TRANSFUSION, 39(11-12), 1999, pp. 1212-1219
BACKGROUND: Various open and semi-closed methods are used for red cell (RBC
) depletion and hematopoietic progenitor cell (HPC) enrichment of bone marr
ow (BM) in vitro, but with variable efficacy. A simple, efficient, and safe
method using dextran 110k was developed.
STUDY DESIGN AND METHODS: An equal volume of 4.5-percent dextran was applie
d to major ABO-incompatible BM in transfer bags and sedimentation was allow
ed for 30 minutes. RBCs, nucleated cells (NCs), and mononuclear cells (MNCs
) from BM allografts before and after dextran sedimentation (DS) were count
ed. Flow cytometry, short-term cultures, and long-term cultures were perfor
med to assay the respective recovery of CD34+ cells, colony-forming units (
CFUs), and longterm culture-initiating cells (LTC-ICs).
RESULTS: Sixteen BM collections were processed. The mean volume was 666 mL
(range, 189-1355 mL).The mean II SD post-DS NC, MNC, CD34+ cell, and CFU co
unts per kg of the recipient's body weight were 4.11 +/- 1.74 x 10(8), 8.98
+/- 3.68 x 10(7), 2.90 +/- 1.95 x 10(6), and 2.03 +/- 2.01 x 10(5), respec
tively, with the corresponding post-DS recovery being 90.6 percent, 90 perc
ent, 92.4 percent, and 100.8 percent. The numbers of LTC-ICs in cultures (u
p to 12 weeks) of pre-DS and post-DS samples of five BM allografts were com
parable (p = 0.91). Residual RBCs were 5.1 +/- 4.6 (0.1-14) mt with depleti
on of 96.5 +/- 3.2 percent. There was no significant difference in the mean
absolute RBC count in post-DS BM allografts and in four ficoll-treated BM
allografts (8.09 x 10(10) vs. 4.9 x 10(9); p = 0.206) and in eight major AB
O-incompatible peripheral blood HPC collections (8.09 x 10(10) vs. 9.81 x 1
0(10); p = 0.87). No posttransplant hemolysis was encountered. Engraftment
occurred at 22 +/- 7 days, which is similar to that of four transplants wit
h ficoll-treated BM allografts (22 +/- 9; p = 0.611) and 54 unprocessed BM
allografts (19 +/- 6; p = 0.129).
CONCLUSION: DS is an efficient method of depleting RBCs in major ABO-incomp
atible BM allografts without significant loss of HPCs.