Processing of major ABO-incompatible bone marrow for transplantation by using dextran sedimentation

Area of Science:

• Hematology
• Transplantation Medicine
• Cellular Biology

Background:

• Current methods for red blood cell (RBC) depletion and hematopoietic progenitor cell (HPC) enrichment from bone marrow (BM) have variable efficacy.
• A novel, simple, efficient, and safe method utilizing dextran 110k was developed for this purpose.

Purpose of the Study:

• To evaluate the efficacy of dextran sedimentation (DS) for RBC depletion and HPC enrichment in major ABO-incompatible bone marrow allografts.
• To assess the impact of DS on the recovery and function of hematopoietic progenitor cells.

Main Methods:

• Bone marrow (BM) allografts were treated with a 4.5% dextran solution followed by 30 minutes of sedimentation.
• Quantification of RBCs, nucleated cells (NCs), and mononuclear cells (MNCs) before and after DS.
• Flow cytometry and various cell cultures (short-term, long-term) were used to assess CD34+ cell, colony-forming unit (CFU), and long-term culture-initiating cell (LTC-IC) recovery.

Main Results:

• DS achieved 96.5% RBC depletion with high recovery rates for CD34+ cells (92.4%) and CFUs (100.8%).
• Long-term culture-initiating cell (LTC-IC) numbers were comparable between pre-DS and post-DS samples (p=0.91).
• Engraftment times were similar to those observed with ficoll-treated or unprocessed BM allografts, with no post-transplant hemolysis.

Conclusions:

• Dextran sedimentation (DS) is an effective method for depleting RBCs in major ABO-incompatible BM allografts.
• The DS method demonstrates minimal loss of vital hematopoietic progenitor cells (HPCs).
• This technique offers a safe and efficient approach for preparing BM for transplantation.