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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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| 5. |
- 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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| 6. |
- 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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| 8. |
- Widell, Anders, et al.
(författare)
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At least three hepatitis C virus strains implicated in Swedish and Danish patients with intravenous immunoglobulin-associated hepatitis C
- 1997
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Ingår i: Transfusion. - : Wiley. - 0041-1132 .- 1537-2995. ; 37:3, s. 313-20
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Three reported Swedish cases of hepatitis C in patients receiving an intravenous immunoglobulin (Gammagard, Baxter Healthcare, Deerfield, IL) were among the first to bring to light a worldwide outbreak of hepatitis C associated with non-solvent/detergent (SD)-treated Gammagard. In February 1994, all implicated batches of Gammagard were recalled and exposed patients traced. STUDY DESIGN AND METHODS: Sera from all identified and hepatitis C-viremic Swedish and Danish patients (n = 14) exposed to the implicated batches underwent hepatitis C virus genotyping and sequencing of the core region and hypervariable region 1 of E2. Genomic amplification was also done on 15 non-SD-treated batches of Gammagard. RESULTS: Twelve patients were infected with subtype 1a and surprisingly, two with subtype 2b. Analysis of the core region showed identical sequences in four patients and the only consistently positive batch. Five patients shared another sequence, whereas three other subtype 1a patients each manifested unique sequences. The two subtype 2b isolates were identical. Genomic fingerprinting of the hypervariable region confirmed identity within each group with great stringency. Amplification with isolate-specific primers showed mixed infection in one patient whose exposure was confined to a single batch. CONCLUSION: The few batches implicated presumably were contaminated with several strains.
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| 9. |
- Björkman, Per, et al.
(författare)
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Hepatitis C virus and GB virus C/hepatitis G virus viremia in Swedish blood donors with different alanine aminotransferase levels
- 1998
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Ingår i: Transfusion. - 1537-2995. ; 38:4, s. 378-384
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Hepatitis C virus (HCV) is a known blood-borne hepatotropic virus for which antibody screening of blood donors is universally practiced. The newly identified GB virus C (GBV-C) and its strain variant hepatitis G virus (HGV) are of unknown pathogenic significance, and screening of blood donors for this agent has not yet been implemented. Polymerase chain reaction (PCR) is the most sensitive method for detecting HCV viremia and is the only method presently available for the diagnosis of GBV-C/HGV infection. STUDY DESIGN AND METHODS: RNA extracts of sera from 577 anti-HCV-negative blood donors (393 with elevated alanine aminotransferase [ALT] levels, 184 with normal ALT levels) were tested with nested PCR for HCV and GBV-C/HGV directed at the 5'-noncoding regions of the two viruses. RESULTS: One donor with elevated ALT was HCV PCR positive. This donor was anti-HCV negative when recruited to the study but subsequently developed anti-HCV. Of the 19 donors with GBV-C/HGV viremia in the series as a whole, 16 belonged to the group with elevated ALT levels and 3 to the group with normal ALT levels; the group difference in prevalence was nonsignificant (4.1% [16/393] vs. 1.6% [3/184; p = 0.20]). Phylogenetic analysis showed 16 of the GBV-C/HGV isolates to be classifiable as subtype 2a and three as subtype 2b. At follow-up 3 to 5 years later, 11 of 18 donors were still viremic. CONCLUSION: There was no significant difference in GBV-C/HGV viremia in the group with elevated ALT levels and the group with normal ALT levels. The frequency and subtype distribution in the present series were similar to those in other Western countries.
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| 10. |
- Olsson, Martin L, et al.
(författare)
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A clinically applicable method for determining the three major alleles at the Duffy (FY) blood group locus using polymerase chain reaction with allele-specific primers
- 1998
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Ingår i: Transfusion. - 1537-2995. ; 38:2, s. 168-173
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The clinically significant antigens of the Duffy (Fy [FY]) blood group system are expressed on the red cell form of the FY glycoprotein, a promiscuous chemokine receptor and also a receptor for malarial parasites. After the cloning of cDNA coding for FY glycoprotein, the molecular basis of the three major alleles (Fya/Fyb/Fy) has been established. Because of the mistyping of the silent Fy allele as Fyb, the error rate of current genotyping methods is high in black populations. STUDY DESIGN AND METHODS: Two hundred blood donors (European whites and African Blacks) and some amniotic DNA samples were investigated by a new allele-specific primer polymerase chain reaction technique. Sense primers corresponding to normal and GATA-1-mutated FY gene promoter region sequences were combined with antisense primers discriminating the Fya/Fyb polymorphism. RESULTS: Complete correlation between FY phenotypes and genotypes was obtained in all samples studied, although, in two whites and one black, serology showed weak Fyb expression while polymerase chain reaction indicated a Fyb allele. Gene frequencies were calculated. CONCLUSION: This simple and rapid polymerase chain reaction method was shown to detect the three common alleles at the FY locus in two representative ethnic populations. Its future use as an independent technique in red cell FY investigations and for fetal genotyping in hemolytic disease of the newborn is predicted.
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