| 1. |
- Abusibaa, W. A., et al.
(författare)
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Expression of the GBGT1 Gene and the Forssman Antigen in Red Blood Cells in a Palestinian Population
- 2019
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Ingår i: Transfusion Medicine and Hemotherapy. - : S. Karger AG. - 1660-3796 .- 1660-3818. ; 46:6, s. 450-454
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Tidskriftsartikel (refereegranskat)abstract
- Background: The Forssman antigen (FORS1 Ag) is expressed on human red blood cells (RBCs). We investigated its presence on RBCs from Palestinian subjects and Swedish subjects by serological testing and by sequencing part of exon 7 of the GBGT1 gene, which encodes Forssman synthase. -Materials and Methods: Blood samples from Palestinian subjects (n = 211 adults and n = 73 newborns) and from Swedish subjects (n = 47 adults) were analyzed in the study. RBCs from the Palestinian samples were typed for the FORS1 Ag using a monoclonal anti-Forssman antibody. The GBGT1 gene was genotyped by DNA sequencing (all adult samples) or by using amplification refractory mutation system PCR (newborn samples). Results: All of the studied samples were negative for the FORS1 Ag by serologic typing. DNA sequencing of the 3′ end of exon 7 of the GBGT1 gene, which includes Arg296, showed that all samples had the wild-type Arg296 sequence, which is associated with an inactive form of Forssman synthase. We detected four single nucleotide polymorphisms in the adult samples; two were silent (p.Tyr232=, p.Gly290=), and two were missense (p.Arg243Cys, p.Arg243His). The allele frequencies ranged from 0.2 to 3.6%. The p.Arg243Cys SNP was a novel SNP that was detected in one Palestinian sample. Conclusion: Our results confirmed the allelic diversity of GBGT1 and identified a novel nucleotide polymorphism in this gene, p.Arg243Cys. Our results also confirmed that the FORS blood group system is a low-frequency system. © 2019 S. Karger AG, Basel. Copyright: All rights reserved.
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| 2. |
- Andersson, N. E., et al.
(författare)
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Methodological considerations on the determination of the APC response in plasma
- 1995
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Ingår i: Infusionstherapie und Transfusionsmedizin. - : S. Karger AG. - 1019-8466. ; 22:SUPPL. 1, s. 80-82
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Tidskriftsartikel (refereegranskat)abstract
- The performance of COATEST® APC® Resistance on different coagulation instruments has been further evaluated through analysis of plasma from 100 blood donors on KC 10, ST 4, ACL 300R, Electra 900 and Thrombolyzer. The electromechanical instruments KC-10 and ST 4 showed a lower response to APC than the turbidimetric or photometric instruments with median APC ratios of 2.7 and 2.8 for the two former versus 3.1, 3.4 and 3.5, respectively, for the other three, which is in agreement with earlier initial findings. Similarly, the cut-off value varied between 2.1 and 2.6 for these instruments. The correlation of APC ratios between instruments was strong with r values ranging between 0.71 and 0.93 and, furthermore, none of the six plasmas with the lowest APC ratios on the Thrombolyzer ranked higher than 8 on any of the other instruments. Analysis of control plasmas with six consecutive kit batches on ACL and ST4 resulted in APC ratio ranges of 3.3-3.7 and 2.7-3.0 for a normal control and 1.8-2.0 and 1.9-2.0 for an abnormal control on ACL and ST4, respectively, illustrating a high reproducibility between batches. Repeated freezing and thawing of samples is disrecommended since this often resulted in increased APC ratios. In contrast, in spite of up to 40% decrease in FVIII activity upon storage of 10 different plasma samples for 5 h, the effect on the APC ratio was only minor as was also the effect of addition of 1.0 IU/ml of FVIII. In neither case was any sample misclassified. Altogether, the results support the applicability of this kit for measuring the response of plasma to APC.
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| 3. |
- Avent, Neil D., et al.
(författare)
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The Bloodgen Project of the European Union, 2003-2009
- 2009
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Ingår i: Transfusion Medicine and Hemotherapy. - : S. Karger AG. - 1660-3818 .- 1660-3796. ; 36:3, s. 162-167
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Forskningsöversikt (refereegranskat)abstract
- The Bloodgen project was funded by the European Commission between 2003 and 2006, and involved academic blood centres, universities, and Progenika Biopharma S. A., a commercial supplier of genotyping platforms that incorporate glass arrays. The project has led to the development of a commercially available product, BLOODchip, that can be used to comprehensively genotype an individual for all clinically significant blood groups. The intention of making this system available is that blood services and perhaps even hospital blood banks would be able to obtain extended information concerning the blood group of routine blood donors and vulnerable patient groups. This may be of significant use in the current management of multi-transfused patients who become alloimmunised due to incomplete matching of blood groups. In the future it can be envisaged that better matching of donor-patient blood could be achieved by comprehensive genotyping of every blood donor, especially regular ones. This situation could even be extended to genotyping every individual at birth, which may prove to have significant long-term health economic benefits as it may be coupled with detection of inborn errors of metabolism.
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| 4. |
- Flesch, BK, et al.
(författare)
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Multicenter Study on Differential Human Neutrophil Antigen 2 Expression and Underlying Molecular Mechanisms
- 2020
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Ingår i: Transfusion medicine and hemotherapy : offizielles Organ der Deutschen Gesellschaft fur Transfusionsmedizin und Immunhamatologie. - : S. Karger AG. - 1660-3796. ; 47:5, s. 385-395
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Tidskriftsartikel (refereegranskat)abstract
- <b><i>Background:</i></b> The human neutrophil antigen 2 (HNA-2), which is expressed on CD177, is undetectable in 3–5% of the normal population. Exposure of these HNA-2<sub>null</sub> individuals to HNA-2-positive cells can cause immunization and production of HNA-2 antibodies, which can induce immune neutropenia and transfusion-related acute lung injury. In HNA-2-positive individuals, neutrophils are divided into a CD177<sup>pos.</sup> and a CD177<sup>neg.</sup> subpopulation. The molecular background of HNA-2 deficiency and the bimodal expression pattern, however, are not completely decoded. <b><i>Study Design:</i></b> An international collaboration was conducted on the genetic analysis of HNA-2-phenotyped blood samples, including HNA-2-deficient individuals, mothers, and the respective children with neonatal immune neutropenia and regular blood donors. <b><i>Results:</i></b> From a total of 54 HNA-2<sub>null</sub> individuals, 43 were homozygous for the <i>CD177</i>*<i>787A>T</i> substitution. Six carried the <i>CD177</i>*<i>c.1291G>A</i> single nucleotide polymorphism. All HNA-2-positive samples with >40% CD177<sup>pos.</sup> neutrophils carried the *<i>787A</i> wild-type allele, whereas a lower rate of CD177<sup>pos.</sup> neutrophils was preferentially associated with *<i>c.787AT</i> heterozygosity. Interestingly, only the *<i>c.787A</i> allele sequence was detected in complementary DNA (cDNA) sequence analysis carried out on all *<i>c.787AT</i> heterozygous individuals. However, cDNA analysis after sorting of CD177<sup>pos.</sup> and CD177<sup>neg.</sup> neutrophil subsets from HNA-2-positive individuals showed identical sequences, which makes regulatory elements within the promoter unlikely to affect <i>CD177</i> gene transcription in different CD177 neutrophil subsets. <b><i>Conclusion:</i></b> This comprehensive study clearly demonstrates the impact of single nucleotide polymorphisms on the expression of HNA-2 on the neutrophil surface but challenges the hypothesis of regulatory epigenetic effects being implicated in the bimodal CD177 expression pattern.
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| 5. |
- Gassner, Christoph, et al.
(författare)
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Two Prevalent ∼100-kb GYPB Deletions Causative of the GPB-Deficient Blood Group MNS Phenotype S-s-U-in Black Africans
- 2020
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Ingår i: Transfusion Medicine and Hemotherapy. - : S. Karger AG. - 1660-3796 .- 1660-3818. ; 47:4, s. 326-336
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Tidskriftsartikel (refereegranskat)abstract
- The U antigen (MNS5) is one of 49 antigens belonging to the MNS blood group system (ISBT002) carried on glycophorins A (GPA) and B (GPB). U is present on the red blood cells in almost all Europeans and Asians but absent in approximately 1.0% of Black Africans. U negativity coincides with negativity for S (MNS3) and s (MNS4) on GPB, thus be called S-s-U-, and is thought to arise from homozygous deletion of GYPB. Little is known about the molecular background of these deletions. Bioinformatic analysis of the 1000 Genomes Project data revealed several candidate regions with apparent deletions in GYPB. Highly specific Gap-PCRs, only resulting in positive amplification from DNAs with deletions present, allowed for the exact genetic localization of 3 different breakpoints; 110.24- A nd 103.26-kb deletions were proven to be the most frequent in Black Americans and Africans. Among 157 CEPH DNAs, deletions in 6 out of 8 African ethnicities were present. Allele frequencies of the deletions within African ethnicities varied greatly and reached a cumulative 23.3% among the Mbuti Pygmy people from the Congo. Similar observations were made for U+var alleles, known to cause strongly reduced GPB expression. The 110- A nd 103-kb deletional GYPB haplotypes were found to represent the most prevalent hereditary factors causative of the MNS blood group phenotype S-s-U-. Respective GYPB deletions are now accessible by molecular detection of homo- A nd hemizygous transmission.
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| 6. |
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| 7. |
- Ljung, Rolf, et al.
(författare)
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The Fourth Annual Meeting of the International Network for Pediatric Hemophilia: Current Challenges and Recommendations in the Clinical Care of Children with Hemophilia.
- 2010
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Ingår i: Transfusion Medicine and Hemotherapy. - : S. Karger AG. - 1660-3818 .- 1660-3796. ; 37:4, s. 209-212
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Tidskriftsartikel (refereegranskat)abstract
- The International Network for Pediatric Hemophilia (INPH) comprises a group of physicians committed to the unique care of and challenges facing pediatric hemophilia patients. By collaborating on an international level, extensive experience can be shared on current practice, new trends can be discussed and scientifically valid studies can be developed and performed. The three overall objectives of the group (scientific progress, education and networking) are achieved at each annual meeting starting with a round table on the members' current research and clinical activities, project reports of INPH study initiatives, followed by invited educational presentations and interactive discussions. The meetings close with proposals of new projects, future directions of the group and concluding remarks. The Fourth Annual INPH meeting, held in 2009 in Boston, MA, USA, focused on inhibitor development and hemophilic arthropathy in the clinical care of children with hemophilia.
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| 8. |
- Ljungstrom, KG
(författare)
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Safety of Dextran in Relation to Other Colloids - Ten Years Experience with Hapten Inhibition
- 2004
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Ingår i: TRANSFUSION MEDICINE AND HEMOTHERAPY. - : S. Karger AG. - 1660-3796 .- 1660-3818. ; 20:5, s. 206-210
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- <i>Objective:</i> The effects of hapten inhibition with dextran 1 (molecular weight: 1,000 D, Promit®), which is in use since 1982 for the prevention of severe dextran-induced anaphylactic reactions (DIAR) caused by immune complexes, were studied. <i>Design:</i> Spontaneous reports to the manufacturer and to the WHO database INTDIS regarding adverse reactions to clinical dextran after preinjection of dextran 1 and to dextran 1 alone were collected from 1983 to 1992. During this period a total of 5.1 million doses of dextran 1 were sold in 15 countries. <i>Interventions:</i> Analysis of pre- and post-reaction titers of dextran-reactive antibodies (DRA) was made in most Scandinavian reports. <i>Results:</i> The incidence of severe DIAR (grades III-V) to clinical dextran after the prophylactic use of hapten inhibition was approximately 1/200,000 patients receiving dextran 1. In Sweden, where reporting of severe adverse drug reactions is mandatory, the incidence was approximately 1/70,000, indicating a 35-fold reduction. Only 2 fatal reactions were reported, an incidence of 1/2.5 million doses, indicating a 90-fold reduction. Both these occurred in patients with extremely high titers of DRA. Side effects to dextran 1, mostly mild, were reported in approximately 1 case per 100,000 doses. These side effects were not antibody mediated.<i> Conclusions:</i> The above findings, together with other recent safety profile data, suggest that dextran with hapten inhibition has possibly become the safest plasma substitute in current clinical practice.
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| 9. |
- Oldenborg, Per-Arne
(författare)
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Role of CD47 and Signal Regulatory Protein Alpha (SIRP alpha) in Regulating the Clearance of Viable or Aged Blood Cells
- 2012
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Ingår i: Transfusion Medicine and Hemotherapy. - : S. Karger AG. - 1660-3796 .- 1660-3818. ; 39:5, s. 315-320
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Forskningsöversikt (refereegranskat)abstract
- The ubiquitously expressed cell surface glycoprotein CD47 is expressed by virtually all cells in the host, where it can function to regulate integrin-mediated responses, or constitute an important part of the erythrocyte band 3/Rh multi-protein complex. In addition, CD47 can protect viable cells from being phagocytosed by macrophages or dendritic cells. The latter mechanism is dependent on the interaction between target cell CD47 and SIRP on the phagocyte. In this context, SIRP functions to inhibit prophagocytic signaling from Fc gamma receptors, complement receptors, and LDL receptor-related protein-1 (LRP-1), but not scavenger receptors. The expression level and/or distribution of CD47 may be altered on the surface of apoptotic/senescent cells, rendering the phagocytosis inhibitory function of the CD47/SIRP interaction reduced or eliminated. Instead, the interaction between these 2 proteins may serve to enhance the binding of apoptotic/senescent target cells to the phagocyte to promote phagocytosis.
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| 10. |
- Pfau, Giselher, et al.
(författare)
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A Single Dose of Recombinant Activated Factor VII (NovoSeven) Did Not Impair the Function of the Coronary Artery Bypass Grafts : Successful Treatment of Critical Bleeding after Cardiac Surgery in Two Cases
- 2007
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Ingår i: Transfusion Medicine and Hemotherapy. - : S. Karger AG. - 1660-3796 .- 1660-3818. ; 34:3, s. 204-207
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Tidskriftsartikel (refereegranskat)abstract
- Bleeding disorders and hemorrhages cause considerable morbidity and mortality in cardiac surgical patients. Possible thromboembolic complications make the use of recombinant activated factor VII (rFVIIa) in the treatment of bleeding after cardiac surgery controversial. Case Reports: We describe 2 patients who experienced intractable bleeding after open heart surgery with the use of cardiopulmonary bypass. Bleeding was successfully treated by a single dose (90 g/kg) of rFVIIa without affecting the patency of the grafts. Conclusion: rFVIIa may provide an opportunity for an effective treatment of serious bleeding episodes both during cardiac surgery and in the postoperative course.
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