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G Bein

Publications and source records attributed to G Bein.

At least 19 recordsLinked to original sources
PubMed2005

Genotyping of human neutrophil antigen-5a (Ond).

Antibodies to human neutrophil alloantigens (HNA) can cause immune-mediated neutropenias and transfusion complications. The diagnosis of antibodies to the HNA-5a (Ond) isoform of the alphaLbeta2 integrin is hampered by the lack of reliable methods for HNA-5a antigen typing. We have devised a polymerase chain reaction sequence-specific primer method (PCR-SSP) and used it to determine the HNA-5a gene frequencies in 320 individuals from different ethnicities. 15.3% were found to be HNA-5a negative, with no significant deviation between the populations. Results of HNA-5a genotyping were in accordance with phenotyping. Availability of HNA-5a PCR-SSP will facilitate the diagnosis of Ond antibody-mediated clinical conditions.

Alleles↗
PubMed2005

Common human Toll-like receptor 9 polymorphisms and haplotypes: association with atopy and functional relevance.

BACKGROUND: Toll-like receptor 9 (TLR9) is a pattern-recognition receptor that detects unmethylated CpG motifs prevalent in bacterial and viral DNA. TLR9 stimulation is a key event after bacterial infection, triggering innate immunity and T-helper type 1 skewed adaptive immunity. Synthetic CpG-oligodeoxynucleotides (CpG-ODNs) represent a promising and novel class of immune adjuvants for allergy treatment, vaccination, and cancer therapy. However, common functional TLR9 gene variants could interfere with the clinical utilization of CpG-ODN in immunotherapy. Recently, a possible association of TLR9 polymorphism C-1237T with asthma has been reported. OBJECTIVE: The aim of the present study was to investigate whether TLR9 polymorphisms or haplotypes have functional relevance and are associated with atopy. METHODS: We genotyped five common TLR9 single-nucleotide polymorphisms (SNPs) in promoter, exon, and intron regions of the gene in 527 healthy blood donors, and estimated four common haplotypes. The total IgE and specific IgE levels against the most common aeroallergens were measured (n=303). IFN-alpha production by plasmacytoid dendritic cells (pDCs) was analysed after stimulation with TLR9 ligand CpG-ODN (n=220). RESULTS: No significant influence of common TLR9 polymorphisms and haplotypes on the total and specific IgE levels was found. Functional analysis of CpG-ODN-induced IFN-alpha did not indicate a significant role for common TLR9 gene polymorphisms in TLR9 function. CONCLUSION: We conclude that common genetic differences in the TLR9 gene exert no major influence on allergy susceptibility, and are unlikely to have on impact on clinical application of CpG-ODNs.

Genetic Predisposition to Disease↗
PubMed2005

Dendritic cell deficiency in the blood of kidney transplant patients on long-term immunosuppression: results of a prospective matched-cohort study.

Evidence from in vitro studies suggests that immunosuppressive drugs interfere with key functions of dendritic cells (DCs), but the in vivo relevance of these findings is elusive. We prospectively analyzed the major DC precursor subsets in the blood of kidney transplant recipients on long-term immunosuppression (> or =1 year). A total of 87 patients were compared to 87 age- and sex-matched controls. Total DC numbers and the precursor subsets, myeloid type 1 DCs, myeloid type 2 DCs (mDC1, mDC2) and plasmacytoid DCs (pDCs) were identified by four color flow cytometry. Long-term immunosuppression was associated with significant reduction of all major DC subsets in comparison to healthy controls (mDC1 p < 0.001; mDC2 p < 0.0001; two-tailed Mann-Whitney U-test) with the strongest negative impact on pDCs (p < 0.00001). In contrast, total leukocyte numbers were not significantly affected. Analysis of the relative impact of different agents revealed a significant impact of prednisolone on pDCs (p = 0.009) and mDCs2 (p = 0.006). The functional relevance of pDC deficiency was confirmed independently by Interferon-alpha analysis after Toll-like receptor 7 (p < or = 0.001) and 9 (p < 0.05) stimulation. These results indicate for the first time a profound negative impact of long-term immunosuppression on major DC subsets in kidney transplant recipients. DC deficiency may have important implications with respect to viral infections and tumor development.

Adrenal Cortex Hormones↗
PubMed2004

Continuous cytomegalovirus seroconversion in a large group of healthy blood donors.

BACKGROUND AND OBJECTIVES: Transmission of cytomegalovirus (CMV) to seronegative, immunocompromised recipients can cause serious and fatal complications. Although the seroprevalence of CMV is high, the risk of primary CMV infection among healthy blood donors has not yet been analysed in a large population. MATERIALS AND METHODS: We developed an algorithm to determine the rate of CMV seroconversion in an overall cohort of 24,260 subjects who donated 176,474 blood units during an 11-year observation period. RESULTS: We detected CMV seroconversion in all relevant age groups (18-60 years) with an overall seroconversion rate of 0.55% per year. Both CMV seroconversion and seroprevalence occurred more frequently in female donors (P = 0.02 and P < 0.001, respectively). We identified 30-35-year-old blood donors as the group with the highest rate of CMV seroconversion per year (1.33% vs. 0.46%; P < 0.0001). CONCLUSIONS: We conclude that the risk of primary CMV infection is a continuous lifelong event and correlates with age and female gender.

Adolescent↗
PubMed2004

A promoter polymorphism in the CD14 gene is associated with elevated levels of soluble CD14 but not with IgE or atopic diseases.

BACKGROUND: A polymorphism in the promoter region of the CD14 gene, C-159T, has been shown to be associated with increased levels of soluble CD14 (sCD14) and decreased serum immunoglobulin E (IgE) and the expression of a more severe atopic phenotype in previous studies. METHODS: To test if these associations are consistently found in different populations and different age groups, we genotyped 2048 children of different age groups as well as 888 adults from different regions of Germany for the CD14 C-159T polymorphism. RESULTS: While an association between this promoter polymorphism and levels of sCD14 could be confirmed in our study population (CC: 1017 ng/ml vs TT: 1370 ng/ml, P = 0.03), no association between CD14 C-159T genotypes and IgE levels or the prevalence of atopic diseases was seen. CONCLUSIONS: The lack of association between CD14 genotypes and IgE as well as atopic outcomes in this large German study population seems to indicate that CD14 genotypes may not directly be involved in the development of allergies during childhood.

Adult↗
PubMed2003

Novel genetic variation of human interleukin-21 receptor is associated with elevated IgE levels in females.

The interleukin-21 receptor (IL21R) was recently discovered as a novel member of the class-I-cytokine-receptor family and is selectively expressed in lymphoid tissues. IL21R shows strong sequence homologies to the interleukin-4 receptor alpha chain gene (IL4RA). In addition, both genes are adjacent and share structural similarity. We analyzed all the exons of the human IL21R gene and its 5' flanking region for sequence variation. We identified four novel single nucleotide polymorphisms (SNPs) and genotyped 300 healthy blood donors. Total serum IgE levels were measured in all subjects and associated with IL21R SNPs. Results revealed a significant association of one IL21R polymorphism (T-83C) with elevated IgE levels (>100 kU/I) in females (OR=3.000, CI=[1.163;8.385], P=0.015, n=138). This was confirmed in a second prospectively collected group of female blood donors (OR=2.535, CI=[0.927;6.733], P=0.046, n=123). In contrast, no effects were observed in male subjects in either population. These findings identify IL21R as a possible novel target locus influencing IgE synthesis in female individuals.

Female↗
PubMed2002

No linkage of the interleukin-4 receptor locus on chromosome 16p11.2-12.1 with sarcoidosis in German multiplex families.

We typed 241 members of 62 sarcoidosis families with 136 affected siblings for three single nucleotide polymorphisms of the interleukin-4 receptor alpha-chain gene (IL4R). Allele frequencies in patients were compared to those of healthy unrelated control individuals. The segregation of the three-point IL4R haplotypes completed by two flanking highly polymorphic microsatellite polymorphisms revealed no evidence for linkage of the IL4R gene locus with sarcoidosis.

Chromosome Mapping↗
PubMed2001

Ex vivo induction of cytokine mRNA expression in human blood samples.

The interest in the quantitative analysis of cytokine mRNA profiles has increased substantially in recent years. This is based on the potential use of basal cytokine mRNA expression as sensitive markers for in vivo lymphocyte activation in a variety of clinical settings. However, it is less well known to what extent differences in blood collection and preparation techniques may cause ex vivo alteration of quantitative cytokine mRNA levels. We therefore evaluated the effect of blood sampling and the impact of cell separation on interleukin (IL)-2, IL-4, interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha mRNA expression in an intraindividual study design (n=8). Two different blood sampling procedures were applied. A whole blood sample 1 was collected by constant moderate blood flow into a blood collection tube containing lithium-heparin. Moreover, a second sample from the same donor was collected by a 5-fold acceleration of blood flow. Furthermore, peripheral blood mononuclear cell (PBMC) were isolated from the first whole blood sample by density separation over Ficoll-Hypaque. The quantification of cytokine mRNA expression was performed by real-time PCR in native whole blood/PBMC samples or unstimulated cultures. We found a significant increase of IL-2, IL-4 and TNF-alpha mRNA expression (P=0.018, P=0.028, P=0.018) in whole blood samples collected by rapid sampling. The isolation of PBMC by density gradient separation prompted on upregulation of the mRNA levels of IL-2, IL-4 and TNF-alpha 5-9-fold (P=0.018, P=0.018, P=0.018). In contrast, IFN-gamma mRNA expression was not significantly influenced by differences in blood sample preparation. Our data clearly demonstrate that differences in the blood sampling technique or cell separation should be considered as important factors for non-physiological ex vivo induction of cytokine mRNA expression. The current data emphasize the need for data on the impact of ex vivo variation in order to extract reliable and consistent information, particularly when cytokine mRNA expression data from healthy blood donors are included in clinical studies.

Blood Cells↗
PubMed2001

Analysis of interleukin-4 receptor alpha chain variants in multiple sclerosis.

A recent candidate gene study employing microsatellite markers suggested a possible linkage of multiple sclerosis (MS) with the interleukin-4 receptor (IL4R) gene. Consequently, we investigated the association of different IL4R variants with MS in 341 German MS patients and 305 healthy controls. Analysis of the first 100 MS patients for six IL4R variants showed an increased frequency of the R551 variant in MS patients versus healthy controls and carriage of the same IL4R variant was weakly associated with myelin oligodendrocyte glycoprotein (MOG) autoantibody production. However, further analysis of all 341 MS patients did not confirm the finding that this IL4R variant represents a general genetic risk factor for MS but revealed an increased frequency of the R551 variant in MS patients with primary progressive MS (PPMS, n=48) as compared to patients with relapsing remitting MS or secondary progressive MS (RR/SPMS n=284; P=0.005 for genotype differences) and to 305 healthy controls (P=0.001 for genotype differences). This association was statistically independent of the presence of the well-known MS susceptibility allele HLA-DRB1*15. After correction for multiple comparisons only the genotype differences between PPMS patients and healthy controls remained statistically significant. These results indicate, that the IL4R variant R551 may influence the genetic predisposition for PPMS but does not represent a general genetic risk factor for MS.

Adult↗
PubMed2001

Quantification of murine IFN-gamma mRNA and protein expression: impact of real-time kinetic RT-PCR using SYBR green I dye.

Reliable quantification of cytokine mRNA expression is an important technique for analyzing immune responses. Up until now, little to no information has been available as to whether different mRNA quantification techniques lead to similar results. Recently, real time quantitative reverse transcriptase (RT)-PCR using SYBR Green I as a double stranded DNA specific dye has been introduced. This novel method enables simple and rapid measurement of PCR product accumulation during the log-linear reaction phase and obviates the need for expensive hybridization probes. Here, we analyzed murine gamma interferon (IFN)-gamma mRNA expression in splenocytes by this technique in comparison to semiquantitative noncompetitive RT-PCR, Northern blot analysis, and ELISA after stimulation of the cells with interleukin (IL)-12, IL-18 and a combination of both cytokines. The results clearly show that all of the techniques detect differences in the IFN-gamma gene expression induced by these distinctive stimuli qualitatively exactly in the same order. However, real-time kinetic RT-PCR offers several advantages, notably its high sensitivity that allows the detection of basal IFN-gamma mRNA expression in unstimulated samples. In addition it provides the lowest interassay variability of all techniques investigated. Finally, the gene expression measured by this method eliminates any post-PCR manipulations because the PCR product identification can be easily performed by melting curve analysis.

Animals↗
PubMed2001

Workshop report on the genotyping of blood cell alloantigens.

The immunization against alloantigens present on platelets, granulocytes and red blood cells (RBCs) is responsible for various clinical syndromes. Since the molecular basis of these antigens has become clear during the last decade, genotyping is nowadays used in several laboratories. However, many DNA-based techniques still have to be evaluated. We therefore organized a workshop on the genotyping of the most relevant alloantigens on platelets and granulocytes as well as on selected RBC alleles. DNA was isolated from peripheral blood lymphocytes or from B-lymphoblastoid cell lines (B-LCL). We distributed samples for the identification of platelet (n = 7), granulocyte (n = 6) and RBC (n = 4) polymorphisms, respectively. There were 33 institutions in Germany, Austria and Switzerland, which participated in at least one part of the workshop. Twenty-four laboratories reported results on HPA-1, and 23 laboratories on HPA-2, -3, and -5 typing. In addition, five laboratories typed for HPA-4 and -6. The HNA-1a/b (NA1/NA2) alleles were identified by eight laboratories, one of which also typed for HNA-1c (SH). The most frequent genes of the ABO (A1, B, O) and Rh (D, C, c, E, e) systems were typed by 12 participating laboratories, and an additional four laboratories restricted their RBC typing to the RHD gene. The typing technique mainly used for all three cell lineages was the polymerase chain reaction with sequence-specific primers. Other techniques were restriction fragment length analysis, oligonucleotide ligation assay, enzyme-linked mini-sequence assay or direct sequence analysis. The following typing errors were observed: HPA: 15/1442 (1.0%), HNA: 4/108 (3.7%), ABO: 5/96 (5.2%) RH 1/320 (0.3%). Our workshop demonstrated the existence of a number of reliable techniques for the genotyping of blood cell alloantigens and a high standard in the participating laboratories. In addition, we could show the usefulness of B-LCL as a source of reference DNA. However, the 5.2% rate of mistyping in the ABO system demonstrated that further efforts are needed to improve the precision of the genotyping techniques. Future workshops will have to challenge methods and participants with rare variants of RBC genes to guarantee reliable genotyping, e.g. in prenatal diagnosis of fetomaternal incompatibility.

ABO Blood-Group System↗
PubMed2001

Patent ductus arteriosus in very low birthweight infants: complications of pharmacological and surgical treatment.

AIMS: To evaluate complications of surgical and pharmacological treatment of symptomatic patent ductus arteriosus (PDA) in very low birthweight (VLBW) infants. PATIENTS AND METHODS: Of 931 VLBW infants consecutively admitted 1987-1998, a significant PDA prompted first-choice treatment by indomethacin in 101 infants, and surgery in 55 infants. PDA closed or became asymptomatic after indomethacin in 64 patients (63%), while 34 went on to surgery. PDA closure was achieved in all 61 infants after ligation and in 26 of 28 infants after clipping. RESULTS: Transient renal impairment after indomethacin treatment was recorded in 40 of 101 infants (40%), compared to renal impairment in 9 of 55 infants (16%) undergoing surgery without prior indomethacin. No differences in necrotizing enterocolitis and intracranial hemorrhage rates were seen. Air leak occurred in 6 of 89 infants after surgery, two of which had fatal tension pneumothorax. Intraoperative hemorrhage requiring emergency transfusion occurred in 2 infants, wound infection occurred in 2 infants and phrenic palsy in one infant. Based on an intention-to-treat analysis, the overall fatality rates were 16 of 101 (16%) for indomethacin and 14 of 55 (25%) for surgery. CONCLUSIONS: Despite the short-comings inherent to retrospective analyses, we propose that surgery should be reserved for infants not responding to pharmacological PDA closure.

Birth Weight↗
PubMed2000

Association of serology with the endovascular presence of Chlamydia pneumoniae and cytomegalovirus in coronary artery and vein graft disease.

BACKGROUND: Chemotherapeutic treatment for patients with symptomatic coronary artery disease to reduce cardiovascular events may be initiated in response to elevated antibody titers against Chlamydia pneumoniae or cytomegalovirus. How antibody titers are associated with the endovascular presence of these microorganisms is still unclear. METHODS AND RESULTS: Antibody titers against C pneumoniae (microimmunofluorescence) and cytomegalovirus (ELISA) in patients undergoing primary (coronary desobliterates, n=80) or repeated CABG (occluded vein grafts, n=45) were correlated with the endovascular presence of the 2 microorganisms. C pneumoniae was detected by means of a nested polymerase chain reaction (PCR) and by culturing. Both conventional PCR and quantitative PCR were applied for detection of cytomegalovirus. C pneumoniae (PCR/culture) was detected in 19/9% (15/80 and 7/80) of coronary desobliterates and in 18/11% (8/45 and 5/45) of occluded vein grafts. There was no statistical evidence that IgG values differed between patients with or without C pneumoniae detection who were undergoing primary CABG. In contrast, repeated-CABG patients with a positive PCR (P=0.0027) or C pneumoniae culture (P=0.0018) had distinctly elevated IgG titers compared with patients in whom C pneumoniae was not detected. Cytomegalovirus could not be detected in the examined specimens. CONCLUSIONS: Cytomegalovirus infection does not seem to be associated with advanced coronary artery lesions. C pneumoniae antibody titers are not associated with the endovascular presence of C pneumoniae in patients with coronary artery disease. The observed strong association between elevated IgG titers and the detection of C pneumoniae in occluded vein grafts warrants further investigation.

Aged↗
PubMed2000

Errors in ABO typing of blood stains using PCR.

Genotypes of the ABO blood group system were investigated using a multiplex PCR and subsequent restriction enzyme digestion on experimental blood stains. Differences were found when typing blood between the PCR and serological methods and one blood sample, typed as B with the agglutination test was classified as AB using the method described here. The subsequent sequencing procedure revealed the genotype to be BB. Methodological causes for errors in typing which should be taken into consideration are discussed.

ABO Blood-Group System↗
PubMed2000

B-lymphoblastoid cell lines as a source of reference DNA for human platelet and neutrophil antigen genotyping.

BACKGROUND: Human platelet and neutrophil antigens (HPAs, HNAs) are targets for platelet or granulocyte antibodies causing immune thrombocytopenia or neutropenia, respectively. Currently, genotyping is replacing phenotyping as the preferred method of diagnosis of immune cytopenia. To establish a reliable genotyping analysis, however, the availability as reference DNA of genomic DNA from persons of known genotype is essential. STUDY DESIGN AND METHODS: By the use of Epstein-Barr virus transformation, panels of B-lympho-blastoid cell lines (B-LCLs) from HPA- and HNA-phenotyped individuals were developed. Genomic DNA was isolated from these cell lines and tested as reference DNA for genotyping of persons for HPAs and HNAs. RESULTS: DNA derived from these B-LCLs was typed by polymerase chain reaction-restriction fragment length polymorphism and -sequence-specific primers. The results were in accordance with the genotyping from peripheral blood cells. These results were confirmed by 24 laboratories in Germany in a blind study. CONCLUSION: The inexhaustible source of reference DNA derived from B-LCLs allowed the evaluation of reliable HPA and HNA genotyping for quality control purposes. It should facilitate the development of DNA typing in blood centers and clinical laboratories.

Antigens↗
PubMed2000

Arterial switch procedure for D-transposition of the great arteries: quantitative midterm evaluation of hemodynamic changes with cine MR imaging and phase-shift velocity mapping-initial experience.

PURPOSE: To evaluate cine magnetic resonance (MR) imaging and phase-shift velocity mapping for assessment of the hemodynamic relevance of stenotic segments or specific hemodynamic changes in the great vessels after an arterial switch procedure for correction of D-transposition of the great arteries. MATERIALS AND METHODS: Twenty consecutive patients (age range, 2-17 years) with an acoustic window that was insufficient for Doppler transthoracic echocardiography were included in the study. Flow and diameter measurements of the pulmonary arterial trunk and its primary branches were performed with phase-shift velocity mapping and cine MR imaging. RESULTS: There were good correlations between pressure gradients in the pulmonary arteries estimated with MR imaging and those measured with Doppler echocardiography (r = 0.83, n = 15) and cardiac catheterization (r = 0.90, n = 13). Cine MR imaging revealed that the diameters of the right and left pulmonary arteries decreased with the expansion of the aorta during systole, which increased the peak velocity. This temporary stenosis was more severe in the right than in the left pulmonary artery and was accompanied by a significantly (P <.05) lower volume flow in the right artery. CONCLUSION: The anatomic situation after arterial switch repair tended to produce temporary stenoses in the primary pulmonary arterial branches, with significant changes in hemodynamics. These changes may affect the long-term outcome and go undetected with other imaging modalities.

Adolescent↗