Human bone marrow processing using a new continuous-flow cell separation device

Processing of bone marrow (BM) is often required to remove incompatible red blood cells (RBCs) or to reduce the volume before transplantation or cryopreservation. We have evaluated the Spectra Optia apheresis system to determine its effectiveness in volume reduction and RBC depletion of human BM before transplantation.

BM from 30 donations (28 allogeneic and two autologous) were processed using the Spectra Optia over a 12-month period. The mean BM collection volume was 1094 ± 337 mL and RBC volume was 374 ± 148 mL. Processing using the Spectra Optia was as described by the manufacturer.

Volume reduction achieved was 93.0 ± 1.2%; RBC depletion was 98.8 ± 0.4%; and mononuclear, CD34+, and CD3+ cell recoveries were 79.12 ± 14.03, 88.36 ± 13.76, and 79.84 ± 16.27%, respectively. In total 26 of 28 processed allografts were transplanted; 24 achieved neutrophil engraftment in 20.7 ± 5.9 days and 18 achieved platelet engraftment in 19.6 ± 8.9 days. Time in transit significantly affected the Spectra Optia's ability to recover mononuclear, CD34+, and CD3+ cells, and the overall age of the BM at the time of processing significantly affected the recovery of mononuclear and CD3+ cells, but not CD34+ cells. Time in storage at 2 to 6°C had no adverse effect on processing.

This study demonstrates that the Spectra Optia can effectively volume reduce and RBC deplete human BM before transplantation. Time in transit should be as short as possible but may be extended up to 24 hours if the donation is refrigerated during transit.