ABSTRACT
Background: Sterility and safety assurance of hematopoietic stem cell (HSC) products is critical in transplantation. Microbial contamination can lead to product disposal and increases the risk of unsuccessful clinical outcomes. Therefore, it is important to implement and maintain good practice guidelines and regulations for the HSC collection and processing unit in each hospital. We aimed to share our experiences and suggest strategies to improve the quality assurance of HSC processing. Methods: We retrospectively analyzed microbial culture results of 11,743 HSC products processed over a 25-year period (January 1996 to May 2021). Because of reorganization of the HSC management system in 2008, the 25-year period was divided into periods 1 (January 1996 to December 2007) and 2 (January 2008 to May 2021). We reviewed all culture results of the HSC products and stored aliquot samples and collected culture results for peripheral blood and catheter samples. Results: Of the 11,743 products in total, 35 (0.3%) were contaminated by microorganisms, including 19 (0.5%) of 3,861 products during period 1 and 16 (0.2%) of 7,882 products during period 2. Penicillium was the most commonly identified microorganism (15.8%) during period 1 and coagulase-negative Staphylococcus was the most commonly identified (31.3%) during period 2. HSC product contamination occurred most often during HSC collection and processing. Conclusions: The contamination rate decreased significantly during period 2, when the HSC management system was reorganized. Our results imply that handling HSC products by trained personnel and adopting established protocols, including quality assurance programs, aid in decreasing the contamination risk.
Subject(s)
Hematopoietic Stem Cell Transplantation , Humans , Hematopoietic Stem Cells , Retrospective Studies , Quality Improvement , StaphylococcusABSTRACT
BACKGROUND: This study was conducted to evaluate the performance of the COM.TEC cell separator (Fresenius HemoCare GmbH) for collecting CD34+ cells in pediatric patients who were intended to have autologous peripheral blood progenitor cell transplantation, with respect to collection variables, prediction power of CD34+ cell yield, and influence on donors. STUDY DESIGN AND METHODS: A total of 26 pediatric solid tumor patients who received mobilization chemotherapy and granulocyte-colony-stimulating factor underwent CD34+ cell collection (n = 96) using the COM.TEC auto mononuclear cell (MNC) program. Patients were divided into a neuroblastoma (NBL) group and a brain tumor group according to the intensity of prior chemotherapy regimens. The collection variables, cellular variables of leukapheresis products, and the peripheral blood cell counts of patients were compared with those acquired using the COBE Spectra (GambroBCT). The CD34+ cell collection efficiency (CE) and the percentage ratios of actual to predicted CD34+ cell yield indicating prediction power were analyzed. RESULTS: Using the COM.TEC auto MNC program, the processing rate was higher and the product volume was smaller (p < 0.05) than those of the COBE Spectra. Platelet (PLT) reduction in peripheral blood and PLT contamination of the products were significantly lower (p < 0.01). The median CE was less than 60% in both patient groups (50.0 and 48.4%, respectively). The actual collected CD34+ cell yields were medians of 66.9 and 76.1% of the predicted values in NBL group and brain tumor group, respectively. CONCLUSION: PBPC collections by the COM.TEC cell separator had advantages of high processing rate, low product volume, and low contamination by PLTs of product. Low PLT loss was observed in pediatric patients who need to collect autologous PBPCs. However, applying CD34+ cell yield prediction was not practical for prospective scheduling of the next collection. More specified data need to be accumulated for more accurate prediction of CD34+ cell yield in pediatric patients.
