Effect of post-storage filters vs. pre-storage filters for leukoreduction of blood components on clinical outcomes: a systematic review and meta-analysis.

BACKGROUND: Leukoreduction has been used to limit the risk of adverse events. The most commonly used methodology is filtration (pre- or post-storage). However, whether pre-storage filtration is better than post-storage filtration needs to be clearly defined, particularly for countries that still use post-storage filtration. This study aimed to synthesize the best available evidence on the effectiveness of pre-storage filters compared with post-storage filters for transfusion reactions, for the occurrence of infections, for the length of hospital stay, and for the death of patients undergoing leukoreduced transfusion. METHODS: We searched the MEDLINE (PubMed), CINAHL (EBSCO), PsycINFO (APA), Scopus (Elsevier), The Cochrane Library (J. Wiley), Web of Science Core Collection (Clarivate Analytics), Embase (Elsevier), and LILACS (VHL) databases and gray literature for eligible studies in August 2020 and updated the search in October 2023. The Joanna Briggs Institute critical assessment tools were applied to analyze the quality appraisal of the studies. GRADE was used to determine the certainty of the evidence. RESULTS: The meta-analysis showed that pre-storage filtration was a protective factor for the occurrence of febrile non-hemolytic transfusion reaction in red blood cells (RR 0.49, 95% CI 0.41-0.59) and platelet concentrate transfusions (RR 0.16, 95% CI 0.12-0.22). The same did not occur for post-surgical infection after platelet concentrate transfusions (RR 0.82, 95% CI 0.65-1.04). Only one study analyzed the length of hospital stay and showed no significant difference between patients who received leukoreduced transfusions according to the type of filter used. According to the GRADE criteria, the certainty of the evidence for febrile non-hemolytic transfusion reactions was low for red blood cells and very low for platelet concentrate due to the high risk of bias. Infection was a low risk due to imprecision. CONCLUSIONS: The results of this review showed that the certainty of recommending the best type of filter (pre- or post-storage) for the benefit of the outcomes analyzed is still fragile; therefore, more robust evidence is needed. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020192202.

Optimizing the recovery of peripheral blood mononuclear cells trapped in leukoreduction filters - A comparison study

Abstract Introduction The isolation of captured peripheral blood mononuclear cells (PBMNCs) from leukoreduction filters (LRFs) can be of great importance in terms of bringing the lost cells back into use. Objective The aim of this study was to evaluate various methods based on their potential to recover the peripheral blood cells from LRFs with a focus on mononuclear cells (MNCs). Method For cell isolation from LRFs, three distinct methods (back-flushing, direct and vacuum pump) were compared through the calculation of the yield of isolated MNCs. The viability of extracted cells was determined by the flow cytometry technique. Moreover, the recovered MNCs were characterized regarding the presence of blood stem cell purification. The cell culture, microscopic observation, and immunophenotyping were employed to characterize the blood stem cells (hematopoietic, mesenchymal and progenitor endothelial stem cells). Results The yield of isolation obtained in the back-flushing, direct and vacuum pump methods were 17.7 ± 1.28, 17.3 ± 0.96 and 21.2 ± 0.90 percent, respectively. Although the highest potential for total blood cell recovery belonged to the vacuum pump method, the lowest cell viability (85.73 ± 4.84%) was observed in this method. However, the isolation process of the back-flushing and direct methods had less effect on cell viability. The characterization of the isolated MNCs displayed that the dominant positive phenotype was for CD34/CD45, indicating hematopoietic stem cells. In addition, the endothelial stem/progenitor cells were significantly detected as CD31/CD133 positive cells. Conclusion According to our results and considering the safety and efficiency potential of each of the applied methods, the back-flushing in comparison with the other methods can be considered a suitable procedure for MNC isolation from LRFs.

Optimizing the recovery of peripheral blood mononuclear cells trapped in leukoreduction filters - A comparison study.

INTRODUCTION: The isolation of captured peripheral blood mononuclear cells (PBMNCs) from leukoreduction filters (LRFs) can be of great importance in terms of bringing the lost cells back into use. OBJECTIVE: The aim of this study was to evaluate various methods based on their potential to recover the peripheral blood cells from LRFs with a focus on mononuclear cells (MNCs). METHOD: For cell isolation from LRFs, three distinct methods (back-flushing, direct and vacuum pump) were compared through the calculation of the yield of isolated MNCs. The viability of extracted cells was determined by the flow cytometry technique. Moreover, the recovered MNCs were characterized regarding the presence of blood stem cell purification. The cell culture, microscopic observation, and immunophenotyping were employed to characterize the blood stem cells (hematopoietic, mesenchymal and progenitor endothelial stem cells). RESULTS: The yield of isolation obtained in the back-flushing, direct and vacuum pump methods were 17.7 ±â€¯1.28, 17.3 ±â€¯0.96 and 21.2 ±â€¯0.90 percent, respectively. Although the highest potential for total blood cell recovery belonged to the vacuum pump method, the lowest cell viability (85.73 ±â€¯4.84%) was observed in this method. However, the isolation process of the back-flushing and direct methods had less effect on cell viability. The characterization of the isolated MNCs displayed that the dominant positive phenotype was for CD34/CD45, indicating hematopoietic stem cells. In addition, the endothelial stem/progenitor cells were significantly detected as CD31/CD133 positive cells. CONCLUSION: According to our results and considering the safety and efficiency potential of each of the applied methods, the back-flushing in comparison with the other methods can be considered a suitable procedure for MNC isolation from LRFs.