| 1. |
- Ledent, Elisabeth, et al.
(författare)
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Factors influencing white cell removal from red cell concentrates by filtration
- 1996
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Ingår i: Transfusion. - : Wiley. - 0041-1132 .- 1537-2995. ; 36:8, s. 714-718
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The preparation of blood components by hard centrifugation results in red cell concentrates with a small amount of plasma. The influence of various plasma factors, temperature, and storage time on white cell reduction by filtration was studied. STUDYDESIGN AND METHODS: Red cell concentrates were suspended in 100 mL of saline- adenine-glucose-mannitol (SAGMAN) solution or in SAGMAN solution in which 5 or 10 mL had been replaced with an equal amount of fresh plasma, albumin (4%), or heat-inactivated plasma. After overnight storage at 4 degrees C, filtration at a slow flow rate (2 hours) was performed. The effect of temperature was studied by filtration at 4 degrees C and 37 degrees C. To study the influence of storage time, red cell concentrates were stored for 4 to 8 hours or 14 to 20 hours at 4 degrees C and filtered through another model of filter. The number of white cells was counted microscopically or by flow cytometry.RESULTS: When 5 or 10 mL of plasma was added, a significantly smaller number of white cells were found after filtration than were found in the SAGMAN control (the median difference between pairs: 23.6 × 10(6) for 5 mL [p = 0.006] and 14.9 × 10(6) for 10 mL [p = 0.003]). The number of white cells was significantly higher with 10 mL of albumin than with 10 mL of plasma (difference, 15.0 × 10(6); p = 0.006). When heat-inactivated plasma was used, the number of white cells was significantly lower than when fresh plasma was used (difference, 0.3 × 10(6); p = 0.009). Filtration at 37 degrees C resulted in a 64-percent reduction in white cells and that at 4 degrees C led to a 99.7-percent reduction (p = 0.006). When the second filter was used, a slight but significantly lower number of white cells was found in the red cell concentrate stored for 14 to 20 hours than in that stored for 4 to 8 hours (difference, 0.03 × 10(6); p < 0.001).CONCLUSION: The amount of plasma in the red cell concentrate and the storage time and temperature are important factors in the outcome of white cell reduction by filtration. The effect of plasma does not seem to be due to a general influence of protein or to the activity of complement or fibrinogen.
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| 2. |
- Ledent, Elisabeth, et al.
(författare)
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Growth Factor Release during Preparation and Storage of Platelet Concentrates
- 1995
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Ingår i: Vox Sanguinis. - : Wiley. - 0042-9007 .- 1423-0410. ; 68:4, s. 205-209
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Tidskriftsartikel (refereegranskat)abstract
- The platelet content of platelet-derived growth factor (PDGF), a mitogen stored in the alpha-granules, was studied during preparation and storage of platelet concentrates (PC) and compared to the growth-promoting activity of platelets, β-thromboglobulin (β-TG) and lactate dehydrogenase (LD). We compared PC prepared from platelet-rich plasma (PRP-PC; n= 10) and from buffy coat. Two different pre-preparation storage periods of the buffy coat were used: 4h (BC-PC:4h; n = 10) and 24 h (BC-PC: 24h; n = 5). The platelet content of PDGF and β-TG was measured by a RIA technique and the growth-promoting activity by incorporation of 3H-thymidine in stimulated fibroblasts. The platelet content of PDGF, β-TG and the growth-promoting activity of the platelets decreased in a similar way during preparation and storage of PRP-PC (31 ±2, 35±2 and 33±7%, respectively, at day 5 of storage; mean ± SEM). The release of LD was minor (3.9 ±0.5% at day 5). At day 1 of storage the platelet content of PDGF was significantly better preserved in BC-PC:4h than in BD-PC:24h (88±2 and 81 ±3%, respectively; p = 0.03). Comparing BC-PC:4h and PRP-PC we found a significantly better preservation of PDGF in BC-PC:4h until day 3 of storage (80±2 and 75±1%, respectively at day 3; p = 0.046). In conclusion the preparation of PC according to the PRP method initially induces a higher loss of PDGF, and hence of the growth-promoting activity, than the BC method.
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| 3. |
- Ledent, Elisabeth, et al.
(författare)
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Inadequate white cell reduction by bedside filtration of red cell concentrates
- 1994
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Ingår i: Transfusion. - : Wiley. - 0041-1132 .- 1537-2995. ; 34:9, s. 765-768
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Tidskriftsartikel (refereegranskat)abstract
- Background: White cell filtration of red cell concentrates is often performed at the bedside, in the ward, with the filter inserted in the blood administration line. The aim of this study was to evaluate the efficiency of this filtration method and compare it to filtration in the blood bank.Study Design and Methods: One-day-old, buffy coat-reduced, hard-packed red cell concentrates in saline-adenine-glucose-mannitol solution were filtered through different filters designed for bedside or laboratory use. With filters designed for bedside use, filtration of red cells was performed under laboratory conditions at fast flow (10 min) or under bedside conditions at slow flow (2 hours). The remaining white cells were counted microscopically. Filters designed for laboratory use were evaluated at fast flow, and the number of contaminating white cells was counted by flow cytometry.Results: With bedside fllters, a significantly higher contamination of white cells was found In the units filtered at slow flow than at fast flow, regardless of the filter used. The number of units with >5 x 106 white cells was 52 (78%) of 67 filtered at slow flow compared to 11 (23%) of 47 at fast flow, all filters taken together. This difference in white cell contamination was mainly due to an increase of polymorphonuclear cells in the red cell concentrates filtered at slow flow. With filters designed for laboratory use, 0 to 2 percent of units (n = 1448) were contaminated with >5 x 106 white cells.Conclusion: Bedside filtration for white cell reduction at slow flow is inefficient for 1-day-old, buffy coat-reduced red cell concentrates.
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| 4. |
- Ledent, Elisabeth, et al.
(författare)
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White Blood Cell Subsets in Buffy Coat-Derived Platelet Concentrates : The Effect of Pre- and Poststorage Filtration
- 2000
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Ingår i: Vox Sanguinis. - 0042-9007 .- 1423-0410. ; 79:4, s. 235-241
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objectives: Our objective was to study the effect of storage time on the filtration of platelet concentrates (PCs). We compared the total number of white blood cells (WBC), as well as the distribution of WBC subsets, in units filtered before and after storage.Materials and Methods: Buffy coat-derived PCs were filtered either fresh or after 5 days of storage, and total WBC were enumerated by flow cytometry. WBC subsets were analyzed by flow cytometry with three-color fluorescence.Results: The total number of white cells before filtration was significantly higher in fresh units compared with stored units, whereas in postfiltration samples the number of white cells was significantly lower in the fresh compared with the stored units. Although absolute numbers were significantly reduced, filtration also induced significant changes in the proportions of subsets in both fresh and stored units; the percentage of T cells was decreased, whereas the percentage of B cells and monocytes was increased after filtration.Conclusion: Our results suggest that prestorage WBC filtration of platelet concentrates is superior in reducing the absolute numbers of WBC. However, both pre- and poststorage WBC filtration significantly affect the proportions of WBC in the final product, decreasing the number of T cells while apparently increasing the proportion of MHC class II-positive cell populations.
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| 5. |
- Ledent-Semple, Elisabeth
(författare)
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A study of factors influencing the quality of blood products during preparation, storage and filtration
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The quality of a cell concentrate to be transfused is dependent on the method of preparation and the storage conditions of the blood products. The aim of this study was to determine, compare and evaluate factors influencing the quality of platelet and erythrocyte concentrates. The influence of the method of preparation on platelet concentrates from whole blood and on leukocyte depletion by filtration of erythrocyte concentrates was studied. In addition, the influence of storage on leukocyte depletion by filtration of platelet and erythrocyte concentrates was investigated.The method of preparation of platelet concentrates from whole blood influenced the release from the platelet α-granules. A significant increase in the release was found in the concentrates prepared from platelet-rich plasma compared with buffy coat. If the buffy coat was allowed to rest for <4 hours before centrifugation, this difference was significant until day 3 of storage. The ability of platelets to stimulate the growth of fibroblasts followed a similar course and decreased during preparation and storage.The method of preparation of erythrocyte concentrates was shown to influence the outcome of leukocyte depletion by filtration. When hard spun, buffy coat depleted, concentrates were used, the number of leukocytes found in the filtrate was significantly higher compared with units that had been supplemented with an additional 5 or 10 ml of plasma. The flow rate during filtration and temperature of the unit was also shown to have an influence on the outcome on the number of leukocytes post filtration.The storage time of both erythrocyte and platelet concentrates resulted in significant differences in the number ofleukocytes found after leukocyte depletion by filtration. A short storage time of erythrocyte concentrates was found to give a higher number of leukocytes after filtration compared with a longer storage time. This was in contrast to platelet concentrates where a filtration just after preparation, i.e. no storage time, gave better leukocyte depletion compared with 5 days of storage.The distribution ofleukocyte subsets was also changed significantly by filtration. Comparing the pre- and post-filtration percentages of subsets in platelet concentrates, we found a lower percentage of T-lymphocytes and a higher percentage of B-lymphocytes and monocytes post filtration. In conclusion, the method of preparation of cell concentrates and the storage time have a substantial impact on the properties of the final product. Standardized and controlled procedures are of great importance in making optimal blood products.
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