Bone Marrow Fractionation by the Haemonetics System: Reduction of Red Cell Mass before Marrow Freezing, with Special Reference to Pediatric Marrow Volumes

Abstract

For purposes of freezing autologous marrow or transplants of allogeneic marrow with major ABO blood group incompatibility, 54 freshly harvested bone marrows from children of 7-65 kg of weight were depleted of their red cells with the Haemonetics V50 system. The marrow volumes ranged from 230 to 1,145 ml, with 17 small (200-399 ml), 18 intermediate (400-799 ml) and 19 large (800-1,200 ml) volumes. After processing, the median recoveries were: volume 24%, red cell mass 18%, and nucleated cells 75%. In the small marrow volume group, a good nucleated cell recovery was achieved at the expense of red cell depletion. The colony-forming units, granulocytes-macrophages (CFU-GM) were normal after thawing of processed, cryopreserved marrows, and good engraftment of both allogeneic and autologous marrows were achieved. We conclude that marrow processing with the Haemonetics V50 system results in adequate red cell depletion and good nucleated cell recovery without open-air contact of marrow or excessive time consumption. For small marrow volumes, however, the red cell depletion was suboptimal, and a bowl size smaller than 125 ml is desirable for pediatric use.

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

“…In the RBC depletion of BM allografts, the additional risk is the hazard of transfusing small quantities of ABO‐incompatible RBCs that would initiate a hemolytic transfusion reaction 2,7 . Earlier methods of albumin fractionation, 1 BC preparation, 2–4 repeated dilutions with third‐party RBCs, 5 gravity sedimentation in HES or gelatin, 6–9, 16,17 and density gradient centrifugation in ficoll‐hypaque or percoll 12–15 were separately developed by other study groups to deplete RBCs, enrich HPCs, and reduce the volume of BM allografts. However, significant cell loss was encountered, with NC recovery varying from 52 to 75 percent 17 …”

“…Various methods, in either open or semi‐closed systems, were developed to deplete RBCs and simultaneously to reduce the volume of BM allografts; these methods include the use of albumin, 1 buffy coat (BC) preparation, 2–4 repeated dilutions with third‐party RBCs, 5 hydroxyethyl starch (HES), 6–9 dextran, 10,11 ficoll‐hypaque, 12,13 percoll, 14,15 gelatin, 16,17 and automated cell separators 18–20 . However, the processing efficacy differs in terms of cell viability, nucleated cell (NC) and colony‐forming unit (CFU) recovery, residual RBCs, and the final component volume, not to mention the complexity of procedures and the processing time required.…”