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E Seifried

Publications and source records attributed to E Seifried.

At least 19 recordsLinked to original sources
PubMed2007

Comparison of three bacterial detection methods under routine conditions.

BACKGROUND AND OBJECTIVES: Since 2004, bacterial screening of platelets has been required in the USA and is also done on a voluntary basis in many European countries. The German Red Cross blood donor services conducted a prospective multicentre study in order to investigate the prevalence of bacterially contaminated pool platelet concentrates and apheresis platelet concentrates. This substudy compares three different bacterial detection systems. STUDY DESIGN AND METHODS: Platelet concentrates were tested in parallel with BacT/ALERT, Scansystem and Pall eBDS (n = 6307) in pool platelets. Apheresis platelets were tested in parallel with BacT/ALERT and Pall eBDS (n = 4730). All initially positive results were evaluated by a standardized procedure including evaluation by a microbiology reference laboratory. RESULTS: One in 6307 pool platelets were confirmed positive by BacT/ALERT, whereas Pall eBDS and Scansystem failed to detect these samples. Only three samples were initially reactive with Pall eBDS without proof of any bacteria strains. The rate of false-positive results was substantially higher for BacT/ALERT (0.25%, 28 in 11,037 tested samples) than for eBDS (0.03%, 3 in 11 037 tested samples) or Scansystem (0.0%, 0 in 6307 tested samples). Three of 4730 apheresis platelets were confirmed positive by BacT/ALERT. These were negative with Pall eBDS. CONCLUSION: Sensitivity was best for BacT/ALERT, whereas specificity was enhanced for Pall eBDS and Scansystem. Scansystem required specially trained staff, whereas BacT/ALERT and Pall eBDS were easy, quick, user-friendly and objective methods.

Bacteria↗
PubMed2006

Blood transfusion in Europe: basic principles for initial and continuous training in transfusion medicine: an approach to an European harmonisation.

Over the past few decades, transfusion medicine and haemotherapy have evolved into complex medical disciplines comprising a broad field of subspecialties such as immunohaematology, blood component production, haemapheresis and haemostaseology. Transfusion medicine is thus an important qualification at the interfaces of analytical laboratory medicine, pharmaceutical production and clinical disciplines such as internal medicine, anaesthesiology or surgery. Physicians specialising in transfusion medicine are valuable and competent partners for these related disciplines when it comes to safe, effective and tailored haemotherapy. Why has transfusion medicine become so complex? On the one hand, one can discern problems such as infectious diseases like the HIV disaster in the past century, resulting in guidelines, directives and laws such as the transfusion law in Germany. Thereby, we now enjoy the highest level of blood product safety ever regarding viral transmission thanks to the broad implementation of PCR testing. On the other hand, there are numerous positive reasons for the increasing complexity of transfusion medicine: Modern medical therapies like stem cell transplantation, cellular therapy, transplantation of solid organs, regenerative medicine and surgery cannot exist without a safe supply of blood products and high quality standard as well as special blood products and laboratory services provided by blood banks and transfusion medicine specialists. Good laboratory practice (GLP), good manufacturing practice (GMP), quality management systems and quality control on the pharmaceutical manufacturer's level are only few examples of the standards in today's blood banking. European directives in the field of blood products, stem cell preparations and tissue have led to higher uniform quality standards for biological preparations in a unified Europe, which is the desired outcome, but which also increases the complexity of this field. In contrast, directives 93/16/EEC and 2001/19/EC, the directives of the European Parliament and of the Council on the mutual recognition of professional qualifications of European doctors currently in force, as well as the impending directive 2005/36/EC, which has to be translated into national law until October 2007, do not include transfusion medicine, blood transfusion or immunohaematology at all. Other medical specialities, which like our field, are not common to all member states of the European Union, are listed in the above mentioned directives with the minimum length of training and minimal requirements for the qualifications. Examples include clinical biology, biological haematology, microbiology-bacteriology, biological chemistry, immunology, thoracic, paediatric or vascular surgery as well as physiotherapy, stomatology, neuro-psychiatry, dermato-venerology, occupational medicine, allergology, geriatrics, gastro-enterological surgery, community medicine, nuclear medicine, pharmacology, accident and emergency medicine or tropical medicine. Most of the above are medical specialities in some member states, but not in all. A concerted initiative inaugurated by the European Network of Transfusion Medicine Societies (EuroNet-TMS) and the European Blood Alliance (EBA) aims to compile the situation of the transfusion medicine speciality throughout Europe. A preliminary summary of the current situation in 15 European states was prepared in 2005 after a first set of questions, which was sent out by us via the EBA platform. The authors appreciate Clair Watts' compilation of the answers provided by the 15 European colleagues. A summary of these answers is depicted in Table 1. However, the initiative aims at a more complex analysis of the different requirements and constituent parts of the qualification in transfusion medicine in different countries. A long-term objective of this initiative might be to introduce the transfusion medicine specialisation into the above mentioned EC directives in order to facilitate mutual recognition of transfusion medicine qualifications throughout Europe.

Blood Transfusion↗
PubMed2006

Intergenic recombination with HLA-C leads to a novel HLA-A*19 allele, HLA-A*2910, that is characterized by a functionally inactive amino acid exchange in the loop connecting the alpha and alpha domains.

This report describes the HLA-A*29 allele (A*2910) that has been identified by sequence-based typing in an 8-year-old Turkish female with leukaemia during search for a family-related stem cell donor. The allele is characterized by a nucleotide substitution (Guanine to Adenine) in exon 3 at position 258, leading to an amino acid exchange from glutamic acid to lysine at position 177. From family analysis and sequence comparison, the HLA-A*2910 allele has arisen from intergenic recombination with HLA-C. Structurally, the amino acid exchange at position 177 is probably functionally inactive due to the location of this amino acid exchange in the loop connecting the alpha(2) and alpha(3) domains.

Alleles↗
PubMed2006

HLA-DRB1*0826 and HLA-DQB1*0627, two novel class II alleles identified in blood stem cell donors of Caucasian origin.

This report describes two novel HLA class II alleles, HLA-DRB1*0826 and HLA-DQB1*0627, that have been identified in two unrelated voluntary blood stem cell donors of Caucasian origin. HLA-DRB1*0826 is characterized by a nucleotide substitution (G to T) in exon 2 at position 163, leading to an amino acid exchange from argenine to leucine. The donor phenotype is HLA-A*0301,*2902; B*3501,*4403; Cw*0401,*1601; DRB1*0101,*0826; DQB1*0402, *0501. The HLA-DQB1*0627 alleles contain a nucleotide substitution at position 184 (T to C) resulting in an amino acid exchange from tyrosine to histidine. Family segregation analysis revealed that the HLA-DQB1*0627 allele belongs to the haplotype A*0101, B*1517, Cw*0701, DRB1*1302, DQB1*0627. The donor phenotype is HLA-A*0101; B*0801,*1517; Cw*0701; DRB1*1302,*1501; DQB1*0602,*0627.

Alleles↗
PubMed2006

Neither an intronic CA repeat within the CD48 gene nor the HERV-K18 polymorphisms are associated with type 1 diabetes.

Type 1 diabetes is an autoimmune heterogeneous disease that is determined by environmental and genetic factors. A possible retroviral etiology has been inferred from the observation that human endogenous retrovirus (HERV)-K18 encoding a superantigen (SAg) has a polymorphism associated with this disease. Type 1 diabetes families from Germany and Belgium were genotyped for the novel HERV-8914 (303 families) and for the known HERV-8594 (284 families) polymorphisms within the SAg-coding region on the HERV-K18. Case-control analysis was performed for the HERV-8914 polymorphism (506 patients) and for the HERV-8594 polymorphism (370 patients) and compared with 350 German controls. Haplotypes were constructed. Additionally, a microsatellite within the CD48 gene was analyzed in German type 1 diabetes families (n=125) as well as in patients (n=375) and in healthy controls (n=350). No association was found for HERV-K18 polymorphisms or the CA repeat within the CD48 gene with type 1 diabetes mellitus either in families or by comparing patients and controls. In conclusion, we cannot confirm a role of HERV-K18 polymorphisms -HERV-8914 and HERV-8594- or of the CD48 CA repeat for type 1 diabetes susceptibility.

Antigens, CD↗
PubMed2006

Fluorescence quencher improves SCANSYSTEM for rapid bacterial detection.

BACKGROUND AND OBJECTIVES: The optimized scansystem could detect contaminated platelet products within 24 h. However, the system's sensitivity was reduced by a high fluorescence background even in sterile samples, which led to the necessity of a well-trained staff for confirmation of microscope results. MATERIALS AND METHODS: A new protocol of the optimized scansystem with the addition of a fluorescence quencher was evaluated. Pool platelet concentrates contaminated with five transfusion-relevant bacterial strains were tested in a blind study. RESULTS: In conjunction with new analysis software, the new quenching dye was able to reduce significantly unspecific background fluorescence. Sensitivity was best for Bacillus cereus and Escherichia coli (3 CFU/ml). DISCUSSION: The application of a fluorescence quencher enables automated discrimination of positive and negative test results in 60% of all analysed samples.

Bacteriological Techniques↗
PubMed2006

Anti-HBc screening of blood donors: a comparison of nine anti-HBc tests.

BACKGROUND AND OBJECTIVES: Since voluntary introduction of hepatitis B virus (HBV) minipool nucleic acid amplification technology (NAT) at the German Red Cross, the expected residual risk of a transfusion-associated HBV infection has been estimated to be 1 : 500,000 - about 10 times higher than for human immunodeficiency virus (HIV) or hepatitis C virus (HCV) infection. Donors demonstrating chronic positivity for antibody to hepatitis B core antigen (anti-HBc), negativity for hepatitis B surface antigen (HBsAg) and polymerase chain reaction (PCR)-negative with a low virus load are a major cause of this increased risk. MATERIALS AND METHODS: Ten-thousand blood donors from our blood-donation centre were screened for anti-HBc using the current PRISM HBc and the new PRISM HBcore assay to evaluate the diagnostic sensitivity and specificity of these tests. PRISM HBc- or PRISM HBcore-reactive samples were further analysed using seven additional tests for anti-HBc, two tests for antibody to hepatitis B surface antigen (anti-HBs), one test for antibody to hepatitis B envelope antigen (anti-HBe) and three HBV NAT assays. RESULTS: From a total of 10,000 donors, nine and 14 samples were reactive only in the PRISM HBc and the PRISM HBcore, respectively, whereas 165 samples were reactive in both anti-HBc assays. Further analysis of these 188 anti-HBc-reactive specimens in a total of nine different anti-HBc assays revealed concordant results for 162 (86.2%) specimens. Sample cut-off values for anti-HBc were significantly (P < 0.01) lower for anti-HBc-only reactive samples compared with specimens that were also reactive for anti-HBs or anti-HBe. CONCLUSIONS: Both PRISM anti-HBc assays revealed that approximately 1.8% of non-prescreened blood donors from Germany were reactive for anti-HBc. Although sensitivity was comparable between both assays, specificity was increased significantly with the PRISM HBcore. High anti-HBc sample cut-off values were indicative for reactivity in other HBV parameters and for concordant results in the nine different anti-HBc assays. Look-back investigations are necessary to estimate the infection risk both of anti-HBc-only positive and of anti-HBc/anti-HBs-positive blood transfusions.

Blood Donors↗
PubMed2006

Quantification of chimerism within peripheral blood, bone marrow and purified leukocyte subsets: comparison of singleplex and multiplex PCR amplification of short tandem repeat (STR) loci.

OBJECTIVE AND METHODS: Chimerism analysis has become a routine diagnostic procedure after haematopoietic allogeneic stem cell transplantation for early detection of relapse of disease or graft failure. Whereas some centres developed individual in-house short tandem repeat (STR) systems, others prefer commercial multiplex PCR systems. However, little is known about inter-assay variation, which could have a significant impact on treatment decision. We therefore compared two commercial multiplex PCR kits with our in-house STR system using different sample sources, such as peripheral blood (PB), bone marrow (BM) and specific leukocyte subsets. RESULTS: Fifty samples of eighteen paediatric patients were analysed. For neither material, PB, BM and leukocyte subtypes, a significant difference between the STR systems tested was observed. Chimerism analyses of each single STR primer, which is component of both the in-house and the commercial STR system, did not reveal significant differences. CONCLUSION: Our analysis demonstrates that similar results can be obtained with both assays, even when using various sample sources. Further evaluation of different test systems will help to increase interlaboratory standardisation of chimerism analyses for early clinical intervention.

Adolescent↗
PubMed2005

Analysis of leukocyte binding to depletion filters: role of passive binding, interaction with platelets, and plasma components.

Since limited knowledge exists on the mechanisms which regulate cell binding to leukocyte removal filter surfaces, we investigated the binding patterns of leukocytes to individual layers of leukocyte depletion filters. After passage of 1 unit of whole blood, blotting of isolated filter layers on glass slides or elution of cells from filter layers revealed that most leukocytes were located within the first 10 of a total of 28 filter layers, peaking at layers 6 to 8, with granulocytes binding on average to earlier filter layers than lymphocytes. Leukocytes preincubated with inhibitors of actin activation showed unchanged distribution between filter layers, suggesting that cytoskeletal activation does not significantly contribute to their binding. When leukocytes were directly incubated with single filter layers, binding of up to 30% of input cells was recorded in the absence of Ca(2+). Immunohistological analyses showed colocalization of platelets and leukocytes, with co-clustering of platelets and leukocytes. Monocytes and to some degree lymphocytes but not granulocytes competed with platelets for filter binding. Precoating of filter layers with individual plasma components showed that hyaluronic acid, plasma type fibronectin, and fibrinogen all increased the binding of leukocytes compared with albumin coating. In conclusion, leukocytes can bind passively to filters in a process which does not require Ca(2+), which is independent of cytoskeletal activation and which may depend on individual plasma components. These results are of importance when new selective cell enrichment or depletion strategies through specific filters are envisaged.

Blood Cells↗
PubMed2005

Evaluation of an automated high-volume extraction method for viral nucleic acids in comparison to a manual procedure with preceding enrichment.

BACKGROUND AND OBJECTIVES: Nucleic acid extraction still harbours the potential for improvements in automation and sensitivity of nucleic acid amplification technology (NAT) testing. This study evaluates the feasibility of a novel automated high-volume extraction protocol for NAT minipool testing in a blood bank setting. MATERIALS AND METHODS: The chemagic Viral DNA/RNA Kit special for automated purification of viral nucleic acids from 9.6 ml of plasma by using the chemagic Magnetic Separation Module I was investigated. Analytical sensitivity for hepatitis C virus (HCV), human immunodeficiency virus-1 (HIV-1), hepatitis B virus (HBV), hepatitis A virus (HAV) and parvovirus B19 (B19) was compared to our present manual procedure that involves virus enrichment by centrifugation. RESULTS: Chemagic technology allows automation of the viral DNA/RNA extraction process. Viral nucleic acids were bound directly to magnetic beads from 9.6-ml minipools. By combining the automated magnetic beads-based extraction technology with our in-house TaqMan polymerase chain reaction (PCR) assays, 95% detection limits were 280 IU/ml for HCV, 4955 IU/ml for HIV-1, 249 IU/ml for HBV, 462 IU/ml for HAV and 460 IU/ml for B19, calculated for an individual donation in a pool of 96 donors. The detection limits of our present method were 460 IU/ml for HCV, 879 IU/ml for HIV-1, 90 IU/ml for HBV, 203 IU/ml for HAV and 314 IU/ml for B19. CONCLUSIONS: The 95% detection limits obtained by using the chemagic method were within the regulatory requirements for blood donor screening. The sensitivities detected for HCV, HBV, HAV and B19 were found to be in a range similar to that of the manual purification method. Sensitivity for HIV-1, however, was found to be inferior for the chemagic method in this study.

Automation↗
PubMed2004

Anti-fetal immune response mechanisms may be involved in the pathogenesis of placental abruption.

Placental abruption is an unpredictable severe complication in pregnancy. In order to investigate the possibility that the activation of the fetal nonadaptive immune system may be involved in the pathogenesis of this disease, IL-6 release from cord blood monocytes was examined by intracellular cytokine staining and flow cytometric analysis. Our results demonstrate that preterm placental abruption (n = 15) in contrast to uncontrollable preterm labor (n = 33) is associated with significantly (P < 0.001) increased release of IL-6 from the fetal monocytes. The same holds true for rhesus disease (n = 9, P < 0.001) that is characterized by a maternal production of antibodies against the rhesus-D antigen expressed by the fetal erythrocytes. This suggests that during rhesus disease, IL-6 release of monocytes is induced by antibody-mediated cross-linking of these cells to the erythrocytes in the fetal circulation. Hence, this assumption favors the idea that also in case of placental abruption, an increased maternal antibody production against paternal antigens leads to an elevated IL-6 release by the fetal monocytes. To elucidate this potential mechanism, the presence of anti-HLA-antibodies was assessed in the maternal circulation of patients with placental abruption (n = 17) and patients with uncontrollable preterm labor (n = 29). The percentage of women producing anti-paternal HLA-antibodies was significantly (P < 0.01) increased in the group of women with preterm placental abruption (47%) in comparison to women with uncontrollable preterm labor (14%). Therefore, our results suggest that an increased humoral immune response of the mother against the fetus may be decisively involved in the pathogenesis of placental abruption.

Abruptio Placentae↗
PubMed2004

A mouse model to study organ homing behaviour of haemopoietic progenitor cells reveals high selectivity but low efficiency of multipotent progenitors to home into haemopoietic organs.

To study the homing behaviour of an enriched multipotent primitive haemopoietic progenitor cell (HPC) population in mice, undifferentiated murine factor-dependent multipotent HPCs (FDCP-mix), stably transfected with the green fluorescence protein gene, were intravenously injected into congenic mice. After 2 or 24 h, cell suspensions were prepared from bone marrow, spleen, lung, liver, muscle, colon, kidney, brain or blood of the mice and analysed by flow cytometry. Using direct quantifiable determination of total HPC numbers homed per organ and a method to estimate the degree of organ contamination by HPC that were present in blood vessels within the organs before preparation, the highest absolute numbers of HPC were detected in the liver and lungs at 2 h but this was sharply decreased at 24 h, whereas HPC selectively accumulated in the bone marrow and spleen at 24 h after transplantation. Only a few HPC were detected in other organs. The seeding efficiency of homed FDCP-mix HPC to the bone marrow and spleen was approximately 1.5% and ranged between that of primary whole bone marrow cells and lineage-depleted freshly isolated bone marrow cells. Pretreatment of HPC with inhibitors of signal transduction indicated that short-term homing of multipotent HPC into haemopoietic organs is an active process requiring co-ordinated intracellular signalling through Rho family small GTPases and protein kinases. Thus, short-term homing of FDCP-mix HPC into haemopoietic organs is of low efficiency but high selectivity, and provides a system to analyse the mechanisms and manipulation of primitive HPC which saves large numbers of donor animals.

Animals↗
PubMed2003

[Significance of mutation analysis in patients with haemophilia A].

Haemophilia A represents the most frequent hereditary bleeding disorder in humans. The disease is caused by mutations within the factor VIII gene leading to decreased or absent factor VIII activities with a bleeding tendency depending on the degree of factor VIII deficiency. Nowadays, the causative mutations can be routinely detected and have substantially improved diagnostic and understanding of the pathophysiology of haemophilia A. Identification of the gene defects in haemophilic families have enabled fast and save carrier diagnosis. The correlation of the genetic defects with the clinical course revealed that the type of mutation represents the most important genetic predisposing factor for inhibitor formation, the most severe complication of treatment with factor VIII concentrates. Mitigated clinical courses of haemophilia A were shown to be due to special types of mutations or the presence of concomitant thrombophilic mutations. Molecular models of the factor VIII protein allowed to investigate the effects of specific mutations thus giving new insights in the structure/function relationship of the factor VIII molecule. These findings might promote the development of novel recombinant factor VIII concentrates with higher efficacy, longer half life and reduced immunogenicity.

Exons↗
PubMed2002

Autologous transplantation of CD133 selected hematopoietic progenitor cells in a pediatric patient with relapsed leukemia.

A pediatric patient with very early meningeal relapse of his CD34(+) CD133(-) pre-B-ALL was transplanted with 2.5 x 10(6)/kg CD133 selected autologous progenitor cells. Enrichment of CD133(+) cells resulted in a purity of 92.3 +/- 3.5% CD133(+). Hematopoietic engraftment with >1.0 x 10(9)/l neutrophils and >50 x 10(9)/l platelets was reached within 13 and 24 days, respectively. At a follow-up of 11(1/2) months after autologous transplantation, the patient is in complete remission. To our knowledge, the successful transplantation with a CD133 selected graft is the first one to be reported worldwide. CD133 selected cells may serve as an alternative in the case of CD34(+) malignancy.

AC133 Antigen↗
PubMed2002

Unbalanced amounts of HLA-DQA1 allele mRNA: DQA1*03 shows high and DQA1*0501 low amounts of mRNA in heterozygous individuals.

Genes of the HLA-DR, DQ region confer strong susceptibility to type 1 diabetes mellitus (IDDM). A possible mechanism of susceptibility is a difference in the amounts of transcripts of predisposing and neutral or protective haplotypes. In this study we developed an assay to compare the amounts of mRNA of two distinct HLA-DQA1 alleles in peripheral blood lymphocytes (PBLs) of heterozygous individuals, using a quantitative RT-PCR with an internal standard covering all HLA-DQA1 specifities. We also developed an algorithm to calculate the amounts of mRNA for two distinct alleles in heterozygous individuals based on the comparison to the same internal standard. In total, 37 HLA-DQA1 heterozygous individuals were analysed, including patients with IDDM (n = 14) and healthy controls (n = 23). Intra-individually, we observed different amounts of mRNA for different HLA-DQA1 alleles in the order: HLA-DQA1*03 > *01 > *0201 > *05. This order was observed in all individuals. We also observed a variation in the ratio of these unbalanced amounts of mRNA in individuals with the same HLA-DQA1 allele combinations. In all allele combinations the average ratio was increased in patients with IDDM compared to the control samples. HLA-DQA1*03 positive and DQA1*03, *05 heterozygous patients had the highest average ratios. Nevertheless, based on limited sample numbers, these differences did not reach significance. We therefore conclude that variations between HLA-DQA1 alleles are not limited to the nucleotide sequence but are also found at the level of amounts of mRNA.

Diabetes Mellitus, Type 1↗