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- Forsberg, B, et al.
(författare)
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The platelet-specific alloantigen PlA1 (HPA-1a): a comparison of flow cytometric immunophenotyping and genotyping using polymerase chain reaction and restriction fragment length polymorphism in a Swedish blood donor population.
- 1995
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Ingår i: Transfusion. - 0041-1132. ; 35:3, s. 241-6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There is an increasing interest in the development of rapid and reliable techniques for platelet alloantigen typing. STUDY DESIGN AND METHODS: By use of standardized flow cytometry and a specific human alloantiserum, 236 Swedish blood donors were immunophenotyped for the platelet-specific alloantigen, PlA1 (HPA-1a). RESULTS: Ten individuals (4.2%) had low fluorescence intensities and were considered PlA1-negative (HPA-1a-negative); all of them also demonstrated a PlA2/PlA2 (HPA-1b/1b) genotype in a polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) assay of the underlying DNA polymorphism. The remaining population had clear positive fluorescence and was regarded as PlA1-positive (HPA-1a-positive). The fluorescence distribution histogram among PlA1-positive (HPA-1a-positive) individuals was dome-shaped, and those individuals who were homozygous for PlA1 (HPA-1a) could not be distinguished from those who were heterozygous. This finding was further substantiated by PCR-RFLP analysis of the PlA1/PlA2 (HPA-1a/1b) genotype; a heterozygous genotype was found among those having a medium fluorescence intensity as well as among those having a strong fluorescence intensity. CONCLUSION: Flow cytometry is a valuable tool for large-scale detection of PlA1 (HPA-1a). However, flow cytometry based on only one antiserum cannot distinguish between homozygous and heterozygous carriers of PlA1 (HPA-1a). For zygosity testing and when platelets are difficult to obtain, the PCR-RFLP technique is the assay of choice.
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- 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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- 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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- Lee, Samuel, et al.
(författare)
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Perceptions and preferences of autologous blood donors
- 1998
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Ingår i: Transfusion (Philadelphia, Pa.). - : Blackwell Publishing. - 1537-2995 .- 0041-1132. ; 38:8, s. 757-763
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The public's perception of autologous blood donation and transfusion as a worthwhile alternative to allogeneic blood transfusion increased dramatically with discovery of the human immunodeficiency virus. However, new concerns are being raised about the health outcomes and cost-effectiveness of the procedure. As more restrictive guidelines for autologous blood donation evolve, opposition from patients concerned about exposure to allogeneic blood may arise. Physicians' ability to reassure patients and garner their support for more restrictive policies requires an understanding of patients' concerns. The motivations, perceptions, and preferences of patients currently participating in autologous blood donation programs were investigated in this study. STUDY DESIGN AND METHODS: Results from two questionnaire studies of 647 autologous blood donors are presented. The questionnaires assessed demographics, risk perceptions, preferences, willingness to pay, and reactions to different interventions designed to decrease patient preference for autologous blood donation. RESULTS: Patients expressed a strong preference for the availability of autologous blood and indicated that they would be willing to pay substantial amounts of money even ii the procedure were not covered by insurance. Despite education about the low risks of complications from allogeneic transfusions, an aversion to allogeneic transfusion and a willingness to pay for autologous blood donation persisted. Patients were not reassured by information on better infectious disease testing or physician recommendation against autologous blood donation. CONCLUSION: Patients currently participating in autologous blood donor programs strongly prefer continued access to this procedure, primarily because they remain concerned about the complications of allogeneic transfusions. They may not be significantly reassured despite increasingly rigorous and costly improvements in donor and component screening.
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- Olsson, Martin L, et al.
(författare)
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Polymorphisms at the ABO locus in subgroup A individuals
- 1996
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 36:4, s. 309-313
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The common ABO allele sequences are known, but little or no genetic information is available on the rare but important A subgroups. STUDY DESIGN AND METHODS: Blood group ABO polymorphism was analyzed in genomic DNA from 45 rare subgroup A individuals by sequence-specific primer polymerase chain reaction and amplified fragment length polymorphism investigating exons VI and VII in the ABO genes. These methods are used to detect specific mutations only, and not all changes that might be present can be detected. ABO genotypes discriminating six alleles (A1, A2, B, O1, O1var, and O2) were determined. RESULTS: The C-->T substitution at nucleotide position 467 (C467T) is not restricted to A2 and cis-AB individuals, but was found also in some A subgroups. Detection of the functionally more relevant C1060-single-point deletion in A2 was accomplished by a novel sequence-specific primer polymerase chain reaction approach. A 100-percent correlation between the C467T and the C1060-mutations was found. Fifteen of 17 samples showing the T646A mutation (described earlier in one case of Ax) showed a positive correlation with the C771T mutation in a frequently occurring O1var allele. The two exceptions were defined serologically as Ax. CONCLUSION: Indications have been found of an evolutionary relationship between A1 alleles and Ael and A3 subgroups as well as between A2 alleles and Aend and Aweak subgroups. Genetic heterogeneity within the Ax and Aint subgroups was also seen.
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