| 1. |
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| 2. |
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| 3. |
- Dykes, Josefina, et al.
(författare)
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Rapid and effective CD3 T-cell depletion with a magnetic cell sorting program to produce peripheral blood progenitor cell products for haploidentical transplantation in children and adults.
- 2007
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 47:11, s. 2134-2142
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Effective T-cell depletion is a prerequisite for haploidentical peripheral blood progenitor cell (PBPC) transplantation. This study was performed to investigate the performance of magnetic cell sorting–based direct large-scale T-cell depletion, which is an attractive alternative to standard PBPC enrichment procedures. STUDY DESIGN AND METHODS: PBPCs were harvested from 11 human leukocyte antigen (HLA)-haploidentical donors. T cells labeled with anti-CD3–coated beads were depleted with a commercially available magnetic separation unit (CliniMACS, Miltenyi Biotec) with either the Depletion 2.1 (D2.1, n = 11) or the novel Depletion 3.1 (D3.1, n = 12) program. If indicated, additional CD34+ selections were performed (n = 6). Eleven patients received T-cell-depleted grafts after reduced-intensity conditioning. RESULTS: The median log T-cell depletion was better with the D2.1 compared to the D3.1 (log 3.6 vs. log 2.3, p < 0.05) and was further improved by introducing an immunoglobulin G (IgG)-blocking step (log 4.5 and log 3.4, respectively). The D3.1 was superior to the D2.1 (p < 0.05) in median recovery of CD34+ cells (90% vs. 78%) and in median recovery of CD3– cells (87% vs. 76%). The median processing times per 1010 total cells were 0.90 hours (D2.1) and 0.35 hours (D3.1). The transplanted grafts (directly T-cell–depleted products with or without positively selected CD34+ cells) contained a median of 10.5 × 106 per kg CD34+, 0.93 × 105 per kg CD3+, and 11.6 × 106 per kg CD56+. Rapid engraftment was achieved in 10 patients. The incidences of acute graft-versus-host disease were less than 10 percent (Grade I/II) and 0 percent (Grade III/IV). CONCLUSION: The novel D3.1 program with IgG blocking enables highly effective, time-saving large-scale T-cell depletion. Combining direct depletion techniques with standard CD34+ selection enables the composition of grafts optimized to the specific requirements of the patients.
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| 4. |
- Halverson, Gregory R, et al.
(författare)
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Murine monoclonal anti-s and other anti-glycophorin B antibodies resulting from immunizations with a GPB.s peptide.
- 2009
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 49, s. 485-494
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The blood group antigens S and s are defined by amino acids Met or Thr at position 29, respectively, on glycophorin B (GPB). Commercial anti-s reagents are expensive to produce because of the scarcity of human anti-s serum. Our aim was to develop hybridoma cell lines that secrete reagent-grade anti-s monoclonal antibodies (MoAbs) to supplement the supply of human anti-s reagents. STUDY DESIGN AND METHODS: Mice were immunized with the GPB(s) peptide sequence TKSTISSQTNGETGQLVHRF. Hybridomas were produced by fusing mouse splenocytes with mouse myeloma cells (X63.Ag8.653). Screening for antibody production was done on microtiter plates by hemagglutination. Characterization of the MoAbs was done by hemagglutination, immunoblotting, and epitope mapping. RESULTS: Eight immunoglobulin G MoAbs were identified. Five antibodies are specific by hemagglutination for s and two MoAbs, when diluted, are anti-S-like, but additional analyses shows a broad range of reactivity for GPB. Typing red blood cells (RBCs) for s from 35 donors was concordant with molecular analyses as were tests on RBCs with a positive direct antiglobulin test (DAT) from 15 patients. The anti-s MoAbs are most reactive with peptides containing the (31)QLVHRF(36) motif, with (29)Thr. By Pepscan analyses, the anti-S-like MoAbs reacted within the same regions as did anti-s, but independently of (29)Met. One antibody was defined serologically as anti-U; however, its epitope was identified as (21)ISSQT(25), a sequence common for both GPA and GPB. CONCLUSION: In addition to their value as typing reagents, these MoAbs can be used to phenotype RBCs with a positive DAT without pre-test chemical modification.
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| 5. |
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| 6. |
- Hellberg, Åsa, et al.
(författare)
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Expression of a novel missense mutation found in the A4GALT gene of Amish individuals with the p phenotype.
- 2008
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 48:3, s. 479-487
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The rare p phenotype is found at a higher frequency in Amish people than in other populations. Different mutations in the 4-alpha-galactosyltransferase gene (A4GALT), responsible for synthesis of P(k) (Gb(3)) antigen, have been found to cause the P(k)-deficient p phenotype. The aim of this study was to explore the molecular background of the p phenotype in people of Amish origin. STUDY DESIGN AND METHODS: Twenty blood samples with the p phenotype, 19 of them from Amish individuals and 1 Pakistani, were investigated. Amplification of genomic DNA by polymerase chain reaction (PCR) and sequencing by capillary electrophoresis were performed. Blood donors of different geographic origin were screened with PCR-allele-specific primer to investigate whether the novel mutation occurs among individuals with common phenotypes. The mutation was also cloned into an expression vector and transfected to Namalwa cells, which do not normally express P(k). P(k) expression on the transfected cells and P/P(k) on red blood cells (RBCs), both with p and with common phenotypes, were analyzed by flow cytometry. RESULTS: All 20 samples were homozygous for 299C>T changing serine to leucine in a region that is highly conserved in homologous genes across species borders. The mutation was not found in any of the 500 alleles of blood donors investigated. P(k) expression was neither observed by serology and flow cytometry on p RBCs from Amish individuals nor following transfection of cells with constructs containing the novel missense mutation. CONCLUSION: A novel A4GALT missense mutation causes the p phenotype in Amish individuals.
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| 7. |
- Hosseini Maaf, Bahram, et al.
(författare)
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An extensive polymerase chain reaction-allele-specific polymorphism strategy for clinical ABO blood group genotyping that avoids potential errors caused by null, subgroup, and hybrid alleles
- 2007
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 47:11, s. 2110-2125
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Tidskriftsartikel (refereegranskat)abstract
- Background: ABO genotyping is complicated by the remarkable diversity at the ABO locus. Recombination or gene conversion between common alleles may lead to hybrids resulting in unexpected ABO phenotypes. Furthermore, numerous mutations associated with weak subgroups and nondeletional null alleles should be considered. All known ABO genotyping methods, however, risk incorrect phenotype predictions if any such alleles are present. Study Design and Methods: An extensive set of allele-specific primers was designed to accomplish hybrid-proof multiplex polymerase chain reaction (PCR) amplification of DNA fragments for detection of ABO alleles. Results were compared with serologic findings and ABO genotypes defined by previously published PCR-restriction fragment length polymorphism/PCR-allele-specific polymorphism (ASP) methods or DNA sequencing. Results: Phenotypically well-characterized samples from blood donors with common blood groups and rare-subgroup families were analyzed. In addition to the commonly encountered alleles (A(1), A(1(467C > T)), A(2), B, O-1, O-1v, and O-2), the new method can detect hybrid alleles thanks to long-range amplification across intron 6. Four of 12 PCR-ASP procedures are used to screen for multiple infrequent subgroup and null alleles. This concept allows for a low-resolution typing format in which the presence of, for example, a weak subgroup or cis-AB/B(A) is indicated but not further defined. In an optional high-resolution step, more detailed genotype information is obtained. Conclusion: A new genotyping approach has been developed and evaluated that can correctly identify ABO alleles including nondeletional null alleles, subgroups, and hybrids resulting from recombinational crossing-over events between exons 6 and 7. This approach is clinically applicable and decreases the risk for erroneous ABO phenotype prediction compared to previously published methods.
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| 8. |
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| 9. |
- Hosseini Maaf, Bahram, et al.
(författare)
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Structural basis for red cell phenotypic changes in newly identified, naturally occurring subgroup mutants of the human blood group B glycosyltransferase.
- 2007
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 47:5, s. 864-875
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Four amino-acid-changing polymorphisms differentiate the blood group A and B alleles. Multiple missense mutations are associated with weak expression of A and B antigens but the structural changes causing subgroups have not been studied. STUDY DESIGN AND METHODS: Individuals or families having serologically weak B antigen on their red cells were studied. Alleles were characterized by sequencing of exons 1 through 7 in the ABO gene. Single crystal X-ray diffraction, three-dimensional-structure molecular modeling, and enzyme kinetics showed the effects of the B allele mutations on the glycosyltransferases. RESULTS: Seven unrelated individuals with weak B phenotypes possessed seven different B alleles, five of which are new and result in substitution of highly conserved amino acids: M189V, I192T, F216I, D262N, and A268T. One of these (F216I) was due to a hybrid allele resulting from recombination between B and O-1v alleles. The two other alleles were recently described in other ethnic groups and result in V175M and L232P. The first crystal-structure determination (A268T) of a subgroup glycosyltransferase and molecular modeling (F216I, D262N, L232P) indicated conformational changes in the enzyme that could explain the diminished enzyme activity. The effect of three mutations could not be visualized since they occur in a disordered loop. CONCLUSION: The genetic background for B-w phenotypes is very heterogeneous but usually arises through seemingly random missense mutations throughout the last ABO exon. The targeted amino acid residues, however, are well conserved during evolution. Based on analysis of the resulting structural changes in the glycosyltransferase, the mutations are likely to disrupt molecular bonds of importance for enzymatic function.
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| 10. |
- Hult, Annika, et al.
(författare)
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Flow cytometry evaluation of red blood cells mimicking naturally occurring ABO subgroups after modification with variable amounts of function-spacer-lipid A and B constructs.
- 2012
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 52, s. 247-251
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Kodecytes bearing synthetic blood group A and B antigens are increasingly being used in transfusion laboratories as serologic mimics of red blood cell (RBC) A(weak) and B(weak) subtypes. The aim of this study was to compare the flow cytometry profile of kodecytes with native ABO subgroups. STUDY DESIGN AND METHODS: A series of A/B kodecytes, each with decreasing A or B antigen expression, were prepared from group O RBCs that were modified with dilutions of function-spacer-lipid KODE technology (FSL) constructs representing a wide serologic range. Using an established flow cytometry method designed for the detection of low levels of A/B antigens, kodecyte profiles were compared with those of native subgroup cells. RESULTS: Kodecytes with positive tube serology from 4+ to 1+ were created with 15 to 2 µg/mL FSL-A or 78 to 10 µg/mL FSL-B transformation solutions. The kodecytes created with higher concentrations of FSL constructs revealed a uniform and/or even distribution of antigens as seen by a single flow cytometry peak more narrow than the broader peaks produced with lower FSL concentrations similar to those found in native A(x) and most B(weak) subgroups. CONCLUSIONS: Although kodecytes are created artificially, they can be designed to mimic the serologic and flow cytometric profiles of native ABO subgroup RBCs.
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| 11. |
- Hult, Annika, et al.
(författare)
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Many genetically defined ABO subgroups exhibit characteristic flow cytometric patterns.
- 2010
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 50, s. 308-323
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A flow cytometric method for detection of low levels of A/B antigen had been developed previously in our laboratory. The aim of this study was to investigate if this approach could be utilized to characterize different ABO subgroups and constitute a useful tool in a reference laboratory. STUDY DESIGN AND METHODS: Blood samples causing ABO discrepancies (n = 94) by routine serology were further analyzed by ABO genotyping and flow cytometry. To verify the specificity of the monoclonal anti-A and -B reagents and to establish normal flow cytometric patterns, samples from 80 blood donors with common phenotypes were also assessed. RESULTS: Distinguishable flow cytometric patterns were detected for several subgroups but were more apparent for A(weak) (n = 80) samples than B(weak) (n = 14). Two subgroups, A(finn) (n = 11) and A(3) (n = 10) displayed diagnostic features and were used to establish reproduciblity over time and between donors. In general, the consistency within subgroups was remarkable. The allelic enhancement phenomenon was clearly visualized among A(x) samples (n = 10) where different alleles in trans resulted in high, low, or no A antigen expression. Nonsubgroup samples including O/A and O/B chimeras or A(h) and B(h) para-Bombay phenotypes displayed clearly distinguishable histograms. Samples from pregnant women (n = 10) displayed acquired A antigen loss, apparently accentuated during the third trimester. CONCLUSIONS: Genetically defined ABO subgroups and other anomalous phenotypes displayed flow cytometric profiles that may contribute valuable information to the investigation of ABO discrepancies. We conclude that the presented assay may complement traditional serology and genetic analysis in the reference laboratory setting.
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| 12. |
- Hult, Annika, et al.
(författare)
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Weak A phenotypes associated with novel ABO alleles carrying the A(2)-related 1061C deletion and various missense substitutions.
- 2010
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 50, s. 1471-1486
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The 1061delC single-nucleotide polymorphism (SNP) has been reported mostly in the context of the common A(2)[A201] allele and typically produces an A(2) phenotype. This study evaluated new A(weak) alleles, each containing 1061delC. STUDY DESIGN AND METHODS: Twenty samples were referred to our laboratory for analysis due to suspected A(weak) phenotypes originally detected at the referring centers. ABO Exons 1 through 7 and flanking intronic regions were sequenced. A antigen expression on red blood cells was analyzed by flow cytometry. Plasma enzyme activity was studied in one case. Molecular three-dimensional modeling techniques studied the potential effects of amino acid changes on the resulting glycosyltransferases (GTs). RESULTS: Thirteen alleles were discovered, each featuring 1061delC with at least 1 of 12 additional SNPs in the coding region. One of these SNPs disrupts the translation initiation codon. Another constitutes the first reported change in the DVD motif. One SNP found in three alleles causes a substitution of one of the four amino acids that differentiates the wild-type A and B enzymes but plasma enzyme analysis by two methods showed only slightly decreased or normal A(2) activity. Flow cytometric analysis semiquantified the A antigen levels in 16 cases featuring 10 of the alleles and ranged from very weak to nearly A(2) levels. However, the majority of the samples displayed A(x)-like patterns. Molecular modeling of some of the GT variants indicated conformational changes that may explain the diminished A expression observed. CONCLUSION: Missense SNPs were identified in 13 novel A(2)-like alleles, which produced a variety of A subgroup phenotypes.
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| 13. |
- Irshaid, N M, et al.
(författare)
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Genomic characterization of the kidd blood group gene:different molecular basis of the Jk(a-b-) phenotype in Polynesians and Finns
- 2000
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 40:1, s. 69-74
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The clinically important Kidd (JK) blood group antigens are carried by the urea transporter in red cells. The rare Jk(a-b-) phenotype can be caused by homozygosity at the JK locus for a silent allele, JK: This phenotype has been recorded in many ethnic groups, but it is most abundant among people originating from the Polynesian Islands and Finland. The molecular basis for Jk(a-b-) is unknown in these populations. STUDY DESIGN AND METHODS: Blood samples from individuals of Swedish, Polynesian, and Finnish origin were collected and characterized by routine JK blood group serology and JK genotyping. Genomic DNA covering the exons and intervening introns of the JK gene coding region was amplified by polymerase chain reaction, and fragments were directly sequenced. RESULTS: Exon and partial intron sequences in the coding region of the JK gene were determined. Finnish and Polynesian Jk alleles were analyzed; the only deviations from consensus were a splice-site mutation (G-->A) in Polynesians, causing skipping of exon 6, and a T871C substitution predicted to disrupt a potential N-glyco-sylation motif (NSS-->NSP) in Finns. Methods for rapid detection of silent Jk alleles were developed for clinical application. CONCLUSION: Polynesians and Finns have two different molecular alterations in their Jk alleles, both of which can now be determined by polymerase chain reaction.
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| 14. |
- Karlsson, Martin, 1978, et al.
(författare)
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Plasma fibrinogen level, bleeding and transfusion after on-pump coronary artery bypass grafting surgery: a prospective observational study
- 2008
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 48:10, s. 2152-2158
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Early identification of patients with increased risk of excessive bleeding and transfusion after cardiac surgery offers the possibility to initiate countermeasures. Fibrinogen is a key protein in the coagulation cascade and thus a potential biomarker for bleeding. We investigated the relationship between preoperative fibrinogen plasma concentration and postoperative bleeding and transfusion after coronary artery bypass grafting (CABG). STUDY DESIGN AND METHODS: A total of 170 patients (mean age, 67 ± 9 years; 75% men) undergoing isolated CABG were included in a prospective observational study. Patient variables (age, sex, operation time, anticoagulation therapy), preoperative laboratory variables (platelet [PLT] count, activated partial thromboplastin time, prothrombin time, and fibrinogen), postoperative bleeding volume, and transfusions during hospital stay were registered. Independent predictors of bleeding volume and transfusion were identified with multiple regression models. RESULTS: Postoperative bleeding volume correlated univariately with preoperative fibrinogen concentration (r = −0.53, p < 0.001) and PLT count (r = −0.26, p = 0.001) but only preoperative fibrinogen concentration was an independent predictor of postoperative bleeding volume. Twenty-nine of the 170 patients (17%) received transfusions with blood products. Independent predictors of transfusion were preoperative fibrinogen concentration (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.1-3.7 per 1-unit decrease; p = 0.027), female sex (OR, 5.0; 95% CI, 1.8-14.7; p = 0.002), and aortic cross-clamp time (OR, 1.03; 95% CI, 1.01-1.06 per minute; p = 0.013). CONCLUSION: The results indicate that preoperative fibrinogen concentration (even within the normal range) is a limiting factor for postoperative hemostasis. Preoperative measurement of fibrinogen concentration provides information about bleeding volume and transfusion requirements after CABG.
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| 15. |
- Love, A, et al.
(författare)
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TT virus infections among blood donors in Iceland: prevalence, genotypes, and lack of relationship to serum ALT levels
- 2000
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 40:3, s. 306-309
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The TT virus (TTV) is a newly identified blood-borne virus. Its association with disease is still unknown, and screening of blood donors has not been implemented. Several genotypes of the TTV have been identified. STUDY DESIGN AND METHODS: Three hundred seventy healthy blood donors were randomly selected and tested for TTV by the PCR method. Sequencing of a part of the genome was performed to identify various genotypes of the virus. ALT levels were determined in both infected and uninfected individuals. RESULTS: The TT virus (TTV), was detected in the sera of 23 (6.2%) of 370 healthy Icelandic blood donors; this prevalence is lower than that reported in Japan but higher than that in Scotland. The virus was found in all groups over the age of 19. Sequencing and phylogenetic analysis of 202 bp from open reading frame 1 demonstrated genotypes 1b and 2b 2c and genotype 4 isolates, with the latter bearing 89-percent nucleotide homology with other genotype 4 sequences deposited at GenBank. One sample showed a mixed genotype 1b/2c infection. Serum ALT levels were within normal limits in all infected individuals. CONCLUSION: The TTV carrier state does not cause significant liver injury.
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| 16. |
- 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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| 17. |
- Scofield, TL, et al.
(författare)
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Evidence that Hy-RBCs express weak Jo(a) antigen
- 2004
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 44:2, s. 170-172
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: RBCs of the Hy- phenotype have, in the past, been typed as Gy(a+(w)), Hy-, Jo(a-), and RBCs with the Jo(a-) phenotype type Gy(a+), Hy-(w), and Jo(a-). Anti-Hy and anti-Jo(a) are difficult to identify mainly because appropriate reagent R6Cs are poorly characterized. Historically, anti-Jo(a) has not reacted with RBCs with either phenotype. This report describes a case of an anti-Jo(a) that shows Hy- RBCs express some Jo(a) antigen, albeit weakly. CASE REPORT: Anti-Jo(a) was identified in a serum sample of a 71-year-old woman. The antibody reacted 1+ to 2+ by the IAT with all untreated and ficin-treated panel RBCs and did not react with Gy(a-) RBCs and Jo(a-) RBCs. Unexpectedly, the serum sample reacted weakly with six of eight RBC samples with the Hy- phenotype. The anti_Jo(a) was adsorbed onto and eluted from Hy- RBCs, indicating the presence of weak Jo(a) antigen. The patient's RBCs typed Gy(a+), Hy+, Jo(a-). DNA studies using PCR-RFLP analysis showed the patient to be homozygous for the JO allele, which is consistent with the serologically determined Jo(a-) status. CONCLUSION: The DNA and serologic evidence of this case show that Hy- RBCs may express low levels of Jo(a) antigen, which contradicts previously published data concerning the Jo(a) type of Hy- RBCs.
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| 18. |
- Sjöberg Wester, Elisabet, et al.
(författare)
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Characterization of Jk(a+(weak) ): a new blood group phenotype associated with an altered JK*01 allele.
- 2011
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 51:2, s. 380-392
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Tidskriftsartikel (refereegranskat)abstract
- The clinically important Kidd (JK) blood group system is considered to be relatively uncomplicated, both serologically and genetically. The JK*01 and JK*02 alleles give rise to Jk(a) and Jk(b) antigens, respectively, and silenced alleles result in Jk(a-b-). Other inherited variants analogous to Fy(x) and weak D phenotypes have not been characterized for JK, although recent abstracts indicate their presence.
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| 19. |
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| 20. |
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| 21. |
- Thuresson, Britt, et al.
(författare)
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ABO transcript levels in peripheral blood and erythropoietic culture show different allele-related patterns independent of the CBF/NF-Y enhancer motif and multiple novel allele-specific variations in the 5'- and 3'-noncoding regions.
- 2008
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 48:3, s. 493-504
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Mechanisms regulating the ABO gene are unclear, especially in the hematopoietic compartment. The number of 43-bp repeats in the CBF/NF-Y-binding enhancer region is considered to have a major influence on transcription. STUDY DESIGN AND METHODS: Transcript levels in peripheral blood and in erythropoietic culture of CD34+ cells from marrow donors were measured with TaqMan assays. The 5'-regulatory region and 3'-downstream sequences were investigated to determine if allelic variations occur. RESULTS: Surprisingly, transcripts from A(1) and A(2) alleles could not be detected in peripheral blood, although transcripts from B/O(1)/O(1v)/O(2) alleles were readily observed. Sequencing of approximately 4 kb upstream and 1.8 kb downstream of the coding region showed multiple novel allele-specific and allele-related motifs. No correlation between these sequence variations and transcript levels was found, however. Contradictory to the results with peripheral blood, in erythropoietic culture of CD34+ cells from healthy marrow donors transcripts from A(1) and A(2) alleles were found at higher levels than transcripts from B/O(1)/O(1v) alleles. CONCLUSION: These data do not support previous suggestions that nonsense-mutated O(1)/O(1v) transcripts are eliminated first. Furthermore, our results contradict the notion that the number of repeats in the upstream CBF/NF-Y-binding enhancer region, which contains four 43-bp repeats in A(2)/B/O(1)/O(1v) but only one 43-bp unit in A(1)/O(2) alleles, determines the transcription rate. The reason for the remarkable discrepancy between blood and marrow remains to be elucidated.
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| 22. |
- Wester, Elisabet S, et al.
(författare)
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Erythroid urea transporter deficiency due to novel JK(null) alleles
- 2008
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 48:2, s. 365-372
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The Kidd blood group antigens Jk(a) and Jk(b) are encoded by the red blood cell (RBC) urea transporter gene. Homozygosity for silent JK alleles results in the rare Jk(a-b-) phenotype. To date, seven JK(null) alleles have been identified, and of these, two are more frequent in the Polynesians and Finns. This study reports the identification of other JK(null) alleles in Jk(a-b-) individuals of different ethnic or geographic origins. STUDY DESIGN AND METHODS: Nine Jk(a-b-) samples and a sample from a Jk(a-b+) mother of a Jk(a+b-) baby were investigated. Polymerase chain reaction amplification and sequence analysis of the JK gene was performed. Western blotting and urea lysis were used to confirm Jk(a-b-) RBCs. RESULTS: Four novel alleles were identified: two different nonsense mutations, 202C > T (Gln68Stop) and 723delA (Ile262Stop) were identified on otherwise consensus JK*1 and JK*2 alleles, respectively. A missense mutation, 956C > T (Thr319Met), was identified in a JK*1 allele from an African-American and a JK*2 allele in two people of subcontinental Indian descent. Immunoblotting and urea lysis confirmed absence of JK glycoprotein in RBC membranes from a sample carrying the 956C > T mutation. Other previously described JK(null) mutations were found in samples of origins other than in which they were first identified. CONCLUSION: The molecular bases of the Jk(a-b-) phenotype are diverse and this is the first report of JK(null) alleles in individuals of African and subcontinental Indian descent. Although rare, these alleles should be taken into consideration when planning genotyping strategies for blood donors and patients.
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| 23. |
- Yazer, Mark H., et al.
(författare)
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Investigation into A antigen expression on O-2 heterozygous group O-labeled red blood cell units
- 2008
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 48:8, s. 1650-1657
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There are two principal types of group O alleles; deletional alleles feature 261delG leading to nonfunctional truncated protein. Nondeletional alleles have the consensus guanosine at residue 261. The major nondeletional allele, O-2, encodes full-length protein with Gly268Arg. While reports vary, O-2 has been proposed to encode weakly functional A-glycosyltransferase (GTA). The main objective of this study was to evaluate if GTA activity is detectable in O-2 donors. STUDY DESIGN AND METHODS: Donor samples from Pittsburgh and Lund were ABO typed by automated methods. DNA was extracted from 779 group O donors whose red blood cells (RBCs) were available for transfusion. ABO genotyping identified those with O-2 alleles. The following tests were performed on randomly selected O-2 samples (number): adsorption-elution with anti-A (3), flow cytometry (15), plasma enzyme activity (4), and attempts to convert group O RBCs to A (2) with O-2 plasma and titration of plasma anti-A/-A(1) (3). RESULTS: Forty O-2-heterozygous donors were identified (5.1%). Adsorption-elution and sensitive flow cytometry did not reveal A antigens on O-2 RBCs. Plasma enzyme analysis failed to show GTA activity above baseline; O-2 plasma was unable to add measurable A antigens to O RBCs. Titers of anti-A/-A(1) appeared reduced in O-2 plasma but did not cause ABO typing discrepancies. No immediate hemolysis or adverse reactions were reported following transfusion of O-2 RBCs to six evaluable group O recipients. CONCLUSIONS: Other than lower plasma anti-A titers, GTA activity was not found in these O-2 samples. Neither automated blood grouping discrepancies nor clinical problems related to transfusing these O-2 units were observed.
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| 24. |
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| 27. |
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| 29. |
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| 30. |
- Edgren, Gustaf, et al.
(författare)
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Improving health profile of blood donors as a consequence of transfusion safety efforts
- 2007
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Ingår i: Transfusion. - : Wiley. - 0041-1132 .- 1537-2995. ; 47:11, s. 2017-2024
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Tidskriftsartikel (refereegranskat)abstract
- Background: Transfusion safety rests heavily on the health of blood donors. Although they are perceived as being healthier than average, little is known about their long-term disease patterns and to which extent the blood banks' continuous efforts to optimize donor selection has resulted in improvements. Mortality and cancer incidence among blood donors in Sweden and Denmark was investigated. Study Design and Methods: All computerized blood bank databases were compiled into one database, which was linked to national population and health data registers. With a retrospective cohort study design, 1,110,329 blood donors were followed for up to 35 years from first computer-registered blood donation to death, emigration, or December 31, 2002. Standardized mortality and incidence ratios expressed relative risk of death and cancer comparing blood donors to the general population. Results: Blood donors had an overall mortality 30 percent lower (99% confidence interval [CI] 29%-31%) and cancer incidence 4 percent lower (99% CI 2%-5%) than the background population. Mortality rates and cancer incidence were lowest for outcomes that are recognized as being related to lifestyle factors such as smoking or to the selection criteria for blood donation. Blood donors recruited in more recent years exhibited a lower relative mortality than those who started earlier. Conclusion: Blood donors enjoy better than average health. Explicit and informal requirements for blood donation in Scandinavia, although mostly of a simple nature, have successfully refined the selection of a particularly healthy subpopulation.
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| 31. |
- Flegel, Willy A, et al.
(författare)
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D variants at the RhD vestibule in the weak D type 4 and Eurasian D clusters
- 2009
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Ingår i: Transfusion. - : Wiley. - 0041-1132 .- 1537-2995. ; 49:6, s. 1059-1069
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: One branch of the RHD phylogenetic tree is represented by the weak D type 4 cluster of alleles with F223V as the primordial amino acid substitution. F223V as well as a large number of further substitutions causing D variants are located at the extracellular RhD protein vestibule, which represents the entrance to the transmembraneous channel of the RhD protein. STUDY DESIGN AND METHODS: RHD and RHCE nucleotide sequences were determined from genomic DNA and cDNA. D epitope patterns were established with commercial monoclonal anti-D panels. RESULTS: The RHD alleles DOL-1 and DOL-2 had the two amino acid substitutions M170T (509T>C) and F223V (667T>G) in common. DOL-2 harbored the additional substitution L378V (1132C>G). Both alleles were observed in Africans and are probably evolutionary related. DMI carried M170I (510G>A), which differed from the DOL-typical substitution. DFW and DFL harbored the substitutions H166P (497A>C) and Y165C (494A>G). The antigen densities of DOL-1, DFL, and DFW were only moderately reduced. CONCLUSION: DOL-1 and DOL-2 belong to the weak D type 4 cluster of RHD alleles. Together with DMI, DFL, and DFW they represent D variants with amino acid substitutions located at extracellular loops 3 or 4 lining the RhD protein vestibule. These substitutions were of minor influence on antigen density while adjacent substitutions in the transmembraneous section caused weak D antigen expression. All these D variants were partial D and alloanti-D immunizations have been observed in DOL-1, DMI, and DFL carriers. The substitution at position 170 causes partial D although located deep in the vestibule.
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| 32. |
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| 33. |
- Hult, Andreas, et al.
(författare)
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Transfusion of cryopreserved human red blood cells into healthy humans is associated with rapid extravascular hemolysis without a proinflammatory cytokine response
- 2013
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Ingår i: Transfusion. - : John Wiley & Sons. - 0041-1132 .- 1537-2995. ; 53:1, s. 28-33
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Transfusion of stored red blood cells (RBCs) can be associated with adverse side effects. Recent studies in mice transfused with stored RBCs showed that a strong proinflammatory cytokine storm was induced due to extravascular hemolysis already at 2 hours after transfusion. Therefore, we here investigated if transfusion of 2 units of cryopreserved autologous RBCs induced a proinflammatory response in healthy human volunteers.STUDY DESIGN AND METHODS: Two units of autologous RBCs, cryopreserved for 16 weeks, were transfused into 10 healthy human volunteers. Serum and blood samples taken at 2 hours before and at 2 and 48 hours after transfusion were analyzed for signs of extravascular hemolysis and the presence of proinflammatory cytokines.RESULTS: At 2 hours after transfusion, transferin-bound serum iron, as well as transferin saturation and total bilirubin, were already significantly increased. These measures all returned back toward that in pretransfusion samples at 48 hours after transfusion. No increases in the production of the proinflammatory cytokines interleukin (IL)-1β, IL-6, IL-8, monocyte chemotactic protein-1, macrophage inflammatory protein-1β, or tumor necrosis factor-α were detected at any time point after transfusion.CONCLUSION: Although a significant level of extravascular hemolysis already occurred at 2 hours after transfusion of cryopreserved RBCs, there were no signs of proinflammatory cytokine production up to 48 hours after transfusion.
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| 34. |
- Högman, Claes F., et al.
(författare)
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Storage of red blood cells with improved maintenance of 2,3-bisphosphoglycerate
- 2006
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Ingår i: Transfusion. - : Wiley. - 0041-1132 .- 1537-2995. ; 46:9, s. 1543-1552
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: During storage, red blood cells (RBCs) rapidly lose 2,3-bisphosphoglycerate (2,3-DPG) leading to an increase in the affinity for O-2 and a temporary impairment of O-2 transport. Recent clinical evaluations indicate that the quality of transfused RBCs may be more important for patient survival than previously recognized. STUDY DESIGN AND METHODS: Glucose-free additive solutions (ASs) were prepared with sodium citrate, sodium gluconate, adenine, mannitol, and phosphates at high pH, a solution that can be heat-sterilized. CP2D was used as an anticoagulant. Additional CP2D was added to the AS to supply glucose. RBCs were stored at 4 degrees C and assayed periodically for intracellular pH (pHi), extracellular pH, glucose, lactate, phosphate, ATP, 2,3-DPG, hemolysis, and morphology. RESULTS: Storage in 175 mL of the chloride-free, hypotonic medium at a hematocrit (Hct) level of 59 to 60 percent resulted in an elevated pHi and the maintenance of 2,3-DPG at or above the initial value for 2 weeks without loss of ATP. The addition of 400 mL of storage solution followed by centrifugation and removal of 300 mL of excess solution to a Hct level of 60 to 66 percent further reduced the chloride concentration, resulting in the maintenance of 2,3-DPG for 4 weeks. Hemolysis was at 0.1 percent at 6 weeks. CONCLUSION: Improvements in the maintenance of 2,3-DPG were achieved with 175 mL of a chloride-free storage solution with familiar additives at nontoxic concentrations to increase pHi. Adding, instead, 400 mL of storage solution followed by the removal of 300 mL reduced the chloride concentration, increasing the pHi and extending the maintenance of 2,3-DPG to 4 weeks.
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| 35. |
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| 36. |
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| 37. |
- Kamper-Jörgensen, Mads, et al.
(författare)
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Survival after blood transfusion
- 2008
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Ingår i: Transfusion. - : Wiley. - 0041-1132 .- 1537-2995. ; 48:12, s. 2577-2584
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Tidskriftsartikel (refereegranskat)abstract
- Long-term survival of transfusion recipients has rarely been studied. This study examines short- and long-term mortality among transfusion recipients and reports these as absolute rates and rates relative to the general population. Population-based cohort study of transfusion recipients in Denmark and Sweden followed for up to 20 years after their first blood transfusion. Main outcome measure was all-cause mortality. A total of 1,118,261 transfusion recipients were identified, of whom 62.0 percent were aged 65 years or older at the time of their first registered transfusion. Three months after the first transfusion, 84.3 percent of recipients were alive. One-, 5-, and 20-year posttransfusion survival was 73.7, 53.4, and 27.0 percent, respectively. Survival was slightly poorer in men than in women, decreased with increasing age, and was worst for recipients transfused at departments of internal medicine. The first 3 months after the first transfusion, the standardized mortality ratio (SMR) was 17.6 times higher in transfusion recipients than in the general population. One to 4 years after first transfusion, the SMR was 2.1 and even after 17 years the SMR remained significantly 1.3-fold increased. The survival and relative mortality patterns among blood transfusion recipients were characterized with unprecedented detail and precision. Our results are relevant to assessments of the consequences of possible transfusion-transmitted disease as well as for cost-benefit estimation of new blood safety interventions.
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| 38. |
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| 39. |
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| 40. |
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| 41. |
- 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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| 42. |
- 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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| 43. |
- 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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| 44. |
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| 45. |
- Lindberg, L, et al.
(författare)
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Is there a clinical need for a diagnostic test allowing detection of chain type-specific anti-A and anti-B?
- 2011
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 51:3, s. 494-503
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Hemagglutination for detection and semiquantification of ABO antibodies is associated with large center-to-center variations and poor reproducibility. Because acceptance for transplantation and diagnosis of rejection in ABO-incompatible transplantation rely on the levels and specificity of ABO antibodies, reproducible tests that allow their detection and specificity determination are required. STUDY DESIGN AND METHODS: The level of chain type-specific anti-A and anti-B were analyzed in the sera of 44 healthy individuals of known ABO blood group using an enzyme-linked immunosorbent assay (ELISA) with polyacrylamide (PAA) conjugates of blood group A and B trisaccharides or Type 2 chain A and B tetrasaccharides. Selected sera were further analyzed by hemagglutination and in an ELISA with Types 1 to 4 chain A or B neoglycolipids (NGL) as antigens. RESULTS: Immunoglobulin (Ig)G anti-A and anti-B levels were higher (p≤0.05) in blood group O than in B and A individuals. More IgM anti-A and anti-B cross-reactivity was detected in AB serum on PAA-conjugated A and B trisaccharides than on the tetrasaccharides. One of 11 blood group B and two of 12 A individuals had IgG antibodies binding the tetrasaccharide despite lack of, or very low reactivity with, the trisaccharides. IgG antibodies preferring the A and B Type 2 tetrasaccharides were of the IgG2 subclass. The NGL ELISA further supported the presence of chain type-specific anti-A and -B antibodies among nonsensitized, healthy individuals. CONCLUSION: An ELISA with structurally defined ABH antigens will allow the antibody class and fine specificity of ABO antibodies to be determined, which may improve risk assessment in ABO-incompatible transplantation.
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| 46. |
- Palfi, Miodrag, 1954-, et al.
(författare)
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A randomized controlled trial of transfusion-related acute lung injury : Is plasma from multiparous blood donors dangerous?
- 2001
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Ingår i: Transfusion. - : Wiley. - 0041-1132 .- 1537-2995. ; 41:3, s. 317-322
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Transfusion-related acute lung injury (TRALI) and other posttransfusion reactions may be caused by granulocyte and/or HLA antibodies, which are often present in blood from multiparous donors. The purpose of this study was to compare the effects of plasma from multiparous donors with those of plasma from donors with no history of transfusion or pregnancy (control plasma) in a prospective, randomized, double-blind, crossover study. STUDY DESIGN AND METHODS: Intensive care patients, judged to need at least 2 units of plasma, were randomly assigned to receive a unit of control plasma and, 4 hours later, a plasma unit from a multiparous donor (=3 live births) or to receive the plasma units in opposite order. The patients were closely monitored, and body temperature, blood pressure, and heart rate were recorded. Blood samples for analysis of blood gases, TNFa, IL-1 receptor antagonist, soluble E selectin, and C3d complement factor were collected at least on four occasions (before and after the transfusion of each unit). RESULTS: Transfusion of plasma from multiparous donors was associated with significantly lower oxygen saturation and higher TNFa concentrations than transfusion of control plasma. The mean arterial pressure increased significantly after the transfusion of control plasma, whereas plasma from multiparous donors had no effect on it. Five posttransfusion reactions were observed in 100 patients, in four cases after the transfusion of plasma from multiparous donors. CONCLUSION: Plasma from multiparous blood donors may impair pulmonary function in intensive care unit patients.
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| 47. |
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| 48. |
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