Evaluation of an automated cell processing device to reduce the dimethyl sulfoxide from hematopoietic grafts after thawing.

Background: The direct transfusion of thawed hematopoietic progenitor cells (HPCs) is associated to transfusion-related side effects that are thought to be dose-dependent on the infused dimethyl sulfoxide (DMSO). Both the effectiveness of a fully automated cell processing device to washing out DMSO and the effects of DMSO elimination over the recovered cells were evaluated.

Study Design And Methods: Twenty cryopre-served peripheral blood HPC bags (HPC apheresis [HPC-A]) were thawed and processed for washing with an automated cell-processing device. Viability, colony-forming units (CFUs), and absolute count of recovered cells were evaluated by flow cytometry immediately after washing as well as at different times after washing and compared with a sample taken just after thawing (control) but maintained at 4 degrees C. DMSO content was measured by high-performance liquid chromatography and the osmolarity with an osmometer.

Results: The median recovery of viable total nucleated cells, viable CD34+ cells, and CFU colonies was 89 (range, 74-115), 103 (range, 62-126), and 91 percent (range, 46%-196%), respectively, in the washing group. Recovery of viable CD3+ cells was 97 percent (range, 42%-131%) and CD14+ cells was 82 percent (54%-119%). The percentages of DMSO elimination and osmolarity reduction were 98 (range, 96-99) and 90 percent (range 86%-95%), respectively. Moreover, elimination of the cryoprotectant improved CFU count, viability, and cell recoveries along the time when compared with the control group.

Conclusion: Washing out DMSO in thawed HPC-A by use of this approach is safe and efficient in terms of recovery and viability of nucleated and progenitor cells. Additionally, the removal degree of DMSO is very high and therefore might ameliorate the transfusion-related side effects.