Validation of Plasma Reduction in Hematopoietic Progenitor Cells for Cryopreservation: Impact on Cell Recovery and Product Safety
Year: 2026
Type: article
Abstract: Introduction Hematopoietic progenitor cell (HPC) transplantation often requires cryopreservation of the cellular product until the time of infusion. Dimethyl sulfoxide (DMSO) is widely used as a cryoprotective agent; however, its toxicity may pose risks, particularly in pediatric patients. Plasma reduction strategies prior to cryopreservation have been adopted to decrease the final product volume and the amount of infused DMSO while maintaining cellular quality and transfusional safety. This study aimed to validate a plasma reduction process for HPC products intended for cryopreservation in a cellular therapy service. Methods This concurrent validation study was conducted at the Cell Processing Center Laboratory between May and December 2025. A total of 41 HPC samples were evaluated, including 34 peripheral blood HPC products (PB-HPC) and seven bone marrow HPC products (BM-HPC). The protocol was based on a previously validated procedure from a partner institution and adapted to the institutional routine. Samples were evaluated at three stages: baseline, pre-procedure, and post-procedure. Parameters analyzed included volume, hematocrit, leukocyte count/µL, leukocytes × 10⁸/mL, leukocytes × 10⁸/bag, leukocytes × 10⁸/kg recipient, and percentage of cell recovery. The predefined acceptance criterion was ≥ 80% recovery in at least 90% of the analyzed samples. Results The mean cell recovery rate was 92.8%. Among the 41 evaluated samples, 97.6% achieved recovery ≥ 80%, meeting the predefined acceptance criteria. Only one sample showed recovery below the established threshold (69%). This sample corresponded to a BM-HPC product intended for a 6.9 kg pediatric patient. In this case, a more extensive plasma reduction was performed to achieve a final infusion volume considered safe, as requested by the attending medical team. Despite the lower recovery rate, the final cell count remained within clinically acceptable parameters for transplantation and was therefore considered a planned deviation. All patients who received processed products during the validation period were monitored by both the cellular therapy service team and the attending physicians, and no adverse events related to product quality or safety were observed. Conclusion The plasma reduction protocol for HPC cryopreservation proved to be safe, reproducible, and effective, demonstrating a high cell recovery rate and compliance with the predefined validation criteria. This strategy enabled volume reduction and potentially decreased DMSO exposure, which is particularly relevant for pediatric patients, without significant impairment of cellular quality. These findings support the definitive implementation of the protocol into the routine practice of the transfusion medicine service.
Language: English
Subfield: Hematology
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7223157565