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1.
Diabet Med ; 38(2): e14389, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32799407

RESUMO

AIMS: To evaluate the diagnostic relevance of autoantibodies against zinc transporter 8 (ZnT8) in schoolchildren from the general population as well as in people with autoimmune diabetes. METHODS: A total of 137 schoolchildren positive for at least one of the three major diabetes-associated autoantibodies, without diabetes heredity or preselection on HLA typing, from the Karlsburg Type 1 Diabetes Risk Study, as well as 102 people at type 1 diabetes onset, 88 people with latent autoimmune diabetes in adults and 119 people with type 2 diabetes, were analysed for different ZnT8 autoantibody variants. RESULTS: Zinc transporter 8 autoantibody positivity was found in 18% of autoantibody-positive schoolchildren, with a noticeable association with other autoantibodies associated with type 1 diabetes and disease progression. Furthermore, ZnT8 autoantibody positivity was associated with diabetes progression in schoolchildren positive for autoantibodies against insulinoma-associated antigen-2 (IA-2) and, importantly, in seven IA-2 autoantibody-negative schoolchildren. Additionally, ZnT8 autoantibodies were found in 56% of people with type 1 diabetes, predominantly directed against all three ZnT8 variants and comparable to schoolchildren with multiple autoantibodies. In contrast, ZnT8 autoantibodies were detected in 10% of people with latent autoimmune diabetes in adults, none of them with reactivity to all three isoforms. CONCLUSION: Zinc transporter 8 autoantibodies are useful markers for prediction of type 1 diabetes in a general population, further stratifying the risk of progression in autoantibody-positive children. ZnT8 autoantibodies are also important markers in adult-onset diabetes, with a completely different reaction pattern in type 1 diabetes in comparison to latent autoimmune diabetes in adults, and may therefore help to differentiate between the two forms.


Assuntos
Autoanticorpos/imunologia , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 2/imunologia , Diabetes Autoimune Latente em Adultos/imunologia , Isoformas de Proteínas/imunologia , Transportador 8 de Zinco/imunologia , Adolescente , Adulto , Idoso , Criança , Diabetes Mellitus Tipo 1/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição de Risco
2.
J Neurol ; 263(10): 2105-13, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27485170

RESUMO

Few regional and seasonal Guillain-Barré syndrome (GBS) clusters have been reported so far. It is unknown whether patients suffering from sporadic GBS differ from GBS clusters with respect to clinical and paraclinical parameters, HLA association and antibody response to glycosphingolipids and Campylobacter jejuni (Cj). We examined 40 consecutive patients with GBS from the greater Munich area in Germany with 14 of those admitted within a period of 3 months in fall 2010 defining a cluster of GBS. Sequencing-based HLA typing of the HLA genes DRB1, DQB1, and DPB1 was performed, and ELISA for anti-glycosphingolipid antibodies was carried out. Clinical and paraclinical findings (Cj seroreactivity, cerebrospinal fluid parameters, and electrophysiology) were obtained and analyzed. GBS cluster patients were characterized by a more severe clinical phenotype with more patients requiring mechanical ventilation and higher frequencies of autoantibodies against sulfatide, GalC and certain ganglioside epitopes (54 %) as compared to sporadic GBS cases (13 %, p = 0.017). Cj seropositivity tended to be higher within GBS cluster patients (69 %) as compared to sporadic cases (46 %, p = 0.155). We noted higher frequencies of HLA class II allele DQB1*05:01 in the cluster cohort (23 %) as compared to sporadic GBS patients (3 %, p = 0.019). Cluster of severe GBS was defined by higher frequencies of autoantibodies against glycosphingolipids. HLA class II allele DQB1*05:01 might contribute to clinical worsening in the cluster patients.


Assuntos
Autoanticorpos/líquido cefalorraquidiano , Glicoesfingolipídeos/imunologia , Síndrome de Guillain-Barré/líquido cefalorraquidiano , Síndrome de Guillain-Barré/genética , Cadeias beta de HLA-DQ/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Infecções por Campylobacter/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Seguimentos , Frequência do Gene , Predisposição Genética para Doença/genética , Alemanha , Síndrome de Guillain-Barré/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Condução Nervosa/genética , Índice de Gravidade de Doença , Adulto Jovem
3.
Diabet Med ; 32(8): 1008-16, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25523979

RESUMO

AIMS: To investigate the occurrence of diabetes-associated autoantibodies and cumulative Type 1 diabetes risk over 18 years in a general population of schoolchildren. METHODS: In the Karlsburg Type 1 Diabetes Risk Study, 11 986 schoolchildren from north-eastern Germany without a family history of diabetes were screened for glutamic acid decarboxylase antibodies, insulinoma-associated antigen-2 antibodies and insulin autoantibodies by radioligand binding assay. Those children found to be autoantibody-positive were invited to follow-up examinations and HLA-DQB1 genotyping, and were followed for progression to Type 1 diabetes. RESULTS: At first follow-up, 119 children had single and 36 children had multiple autoantibodies. Of the multiple autoantibody-positive children, 33 had at least one diabetes-associated HLA-DQB1 allele (*02 and/or *0302). A total of 26 children progressed to Type 1 diabetes, of whom 22 had multiple autoantibodies. The male-to-female ratio of those who progressed to Type 1 diabetes was 1.6. The positive predictive value of multiple autoantibodies was 61.1% compared with only 23.7% for diabetes-associated HLA-DQB1 genotypes among all those who were autoantibody-positive. The cumulative risk was 59.7% after 10 years and 75.1% after 18 years for children with multiple autoantibodies compared with 1.2 and 22.6%, respectively, for children with single autoantibodies (P<0.001). Among the three examined autoantibodies, insulinoma-associated antigen-2 antibodies conferred the highest risk. CONCLUSIONS: The diabetes risk in schoolchildren with multiple autoantibodies was similar to the risk reported in other studies for genetically preselected probands; thus, a combined autoantibody-based screening could effectively identify at-risk individuals from the general population for future intervention trials.


Assuntos
Autoanticorpos/imunologia , Diabetes Mellitus Tipo 1/imunologia , Glutamato Descarboxilase/imunologia , Anticorpos Anti-Insulina/imunologia , Proteínas Repressoras/imunologia , Adolescente , Alelos , Criança , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/genética , Feminino , Predisposição Genética para Doença , Genótipo , Alemanha/epidemiologia , Cadeias beta de HLA-DQ/genética , Humanos , Estudos Longitudinais , Masculino , Valor Preditivo dos Testes , Estudos Prospectivos , Fatores de Risco , Estudos Soroepidemiológicos , Distribuição por Sexo , Adulto Jovem
4.
Tissue Antigens ; 85(2): 93-103, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25515298

RESUMO

In allogeneic hematopoietic stem cell transplantation (HSCT), granulocyte transfusions (GT) may be required in immunocompromised, neutropenic patients. In this context, alloimmunization against alloantigens may occur and affect HSCT outcome. Anti-human leukocyte antigen (HLA) and -MHC class I chain related antigens A (MICA) antibody response after the administration of GT in 29 patients undergoing allogeneic HSCT (n = 27) encompassing 109 sera was investigated by multianalyte microbead assay before and up to 6 month after HSCT. Anti-HLA class I and II antibodies emerged de novo in 11 (38%) and 4 (14%) patients, respectively. Similarly, preformed antibodies were observed in four cases (14%) for anti-HLA class I and also four patients for anti-HLA class II antibodies. Anti-MICA antibodies were observed in eight granulocyte recipients of which three patients developed anti-MICA antibodies after GT, whereas preformed antibodies were seen in five patients. The conversion to positivity for any of the investigated antibodies did not significantly affect overall survival or the incidence of GVHD. GT-associated alloantibody conversion observed did not significantly correlate with outcome. Thus, surveillance of anti-HLA antibodies in the course of GT in the context of HSCT may not be required routinely. The role of MICA antibodies in HSCT and GT, however, requires further study.


Assuntos
Granulócitos/transplante , Transplante de Células-Tronco Hematopoéticas/métodos , Imunização , Adolescente , Adulto , Idoso , Plaquetas/metabolismo , Criança , Pré-Escolar , Feminino , Fluorescência , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Isoanticorpos/imunologia , Masculino , Pessoa de Meia-Idade , Transplante Homólogo , Resultado do Tratamento , Adulto Jovem
5.
Tissue Antigens ; 83(2): 101-5, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24397418

RESUMO

Storage of dried blood spots (DBS) on high-density FTA(®) plates could constitute an appealing alternative to frozen storage. However, it remains controversial whether DBS are suitable for high-resolution sequencing of human leukocyte antigen (HLA) alleles. Therefore, we extracted DNA from DBS that had been stored for up to 4 years, using six different methods. We identified those extraction methods that recovered sufficient high-quality DNA for reliable high-resolution HLA sequencing. Further, we confirmed that frozen whole blood samples that had been stored for several years can be transferred to filter paper without compromising HLA genotyping upon extraction. Concluding, DNA derived from high-density FTA(®) plates is suitable for high-resolution HLA sequencing, provided that appropriate extraction protocols are employed.


Assuntos
DNA/isolamento & purificação , Teste em Amostras de Sangue Seco/métodos , Antígenos HLA/química , Teste de Histocompatibilidade/normas , Alelos , DNA/normas , Teste em Amostras de Sangue Seco/instrumentação , Antígenos HLA/genética , Teste de Histocompatibilidade/instrumentação , Teste de Histocompatibilidade/métodos , Humanos , Controle de Qualidade , Análise de Sequência de DNA , Manejo de Espécimes
6.
Tissue Antigens ; 77(3): 206-17, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21299525

RESUMO

The high degree of polymorphism at human leukocyte antigen (HLA) class I and class II loci makes high-resolution HLA typing challenging. Current typing methods, including Sanger sequencing, yield ambiguous typing results because of incomplete genomic coverage and inability to set phase for HLA allele determination. The 454 Life Sciences Genome Sequencer (GS FLX) next generation sequencing system coupled with conexio atf software can provide very high-resolution HLA genotyping. High-throughput genotyping can be achieved by use of primers with multiplex identifier (MID) tags to allow pooling of the amplicons generated from different individuals prior to sequencing. We have conducted a double-blind study in which eight laboratory sites performed amplicon sequencing using GS FLX standard chemistry and genotyped the same 20 samples for HLA-A, -B, -C, DPB1, DQA1, DQB1, DRB1, DRB3, DRB4, and DRB5 (DRB3/4/5) in a single sequencing run. The average sequence read length was 250 base pairs and the average number of sequence reads per amplicon was 672, providing confidence in the allele assignments. Of the 1280 genotypes considered, assignment was possible in 95% of the cases. Failure to assign genotypes was the result of researcher procedural error or the presence of a novel allele rather than a failure of sequencing technology. Concordance with known genotypes, in cases where assignment was possible, ranged from 95.3% to 99.4% for the eight sites, with overall concordance of 97.2%. We conclude that clonal pyrosequencing using the GS FLX platform and CONEXIO ATF software allows reliable identification of HLA genotypes at high resolution.


Assuntos
Antígenos HLA/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/tendências , Alelos , Sequência de Bases , Método Duplo-Cego , Características da Família , Genótipo , Antígenos HLA/análise , Humanos , Modelos Biológicos , Dados de Sequência Molecular , Estudos Multicêntricos como Assunto , Análise de Sequência de DNA/métodos , Software
7.
Tissue Antigens ; 77(2): 136-42, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21092022

RESUMO

Immunomodulatory properties of IDO1 relate to tryptophan catabolism. The degradation of tryptophan by IDO1 leads to suppression of T cell responses. Recently, another enzyme with IDO-like activity, indoleamine 2,3-dioxygenase-like-protein 1 (INDOL1, IDO2), has been described in both mice and humans. In order to study the gene expression of IDO1 and IDO2, we have developed a quantitative PCR (qPCR) assay. In an exploratory application to the study of the differential expression of IDO1 and IDO2 by professional antigen-presenting cells and MSCs (mesenchymal stromal cells) under the influence of interferon-γ (IFN-γ) and T-lymphocyte conditioned media (TCM), substantial differences were observed. IDO expression measured by qPCR was valid and reliable in the cell types investigated. Further studies are needed to delineate factors driving IDO expression in MSCs.


Assuntos
Células Apresentadoras de Antígenos/enzimologia , Células Dendríticas/enzimologia , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Mesoderma/enzimologia , Células Estromais/enzimologia , Animais , Células Apresentadoras de Antígenos/efeitos dos fármacos , Antivirais/farmacologia , Células Cultivadas , Meios de Cultivo Condicionados/farmacologia , Células Dendríticas/efeitos dos fármacos , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Interferon gama/farmacologia , Mesoderma/citologia , Mesoderma/efeitos dos fármacos , Camundongos , Reação em Cadeia da Polimerase , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Células Estromais/efeitos dos fármacos , Linfócitos T/metabolismo
8.
Tissue Antigens ; 76(5): 362-79, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20545902

RESUMO

We analyzed regional differences in human leukocyte antigen (HLA)-A, -B, and -DR antigen and haplotype frequencies based on a sample of approximately 320,000 German donors in order to identify regions that are especially suited for ongoing stem cell donor recruitment. Geographic partitioning was carried out by postal code regions. Analysis of genetic distances suggests the existence of three regional clusters in South (regions 6-9), East (0-1), and Northwest (2-5) Germany. The southern cluster shows most favorable characteristics with respect to haplotypic and phenotypic diversity and the occurrence of rare HLA antigens. The opposite behavior is shown by regions 2-4 of the northwestern cluster. As a result of lower HLA diversity, completeness of a regional donor file in region 4 with 100,000 donors would be higher than that of a file in region 7 with 170,000 donors. This fact shows the relevance of regional HLA differences for practical donor registry planning. Results such as those presented in this work can be used to diminish the problem of decreasing marginal benefit of donor recruitment, as more than 13 million donors are registered worldwide today.


Assuntos
Antígenos HLA/genética , Transplante de Células-Tronco Hematopoéticas , Doadores de Tecidos , Obtenção de Tecidos e Órgãos , Alelos , Feminino , Frequência do Gene , Genes MHC Classe I , Genes MHC da Classe II , Alemanha , Antígenos HLA-A/genética , Antígenos HLA-B/genética , Antígenos HLA-DR/genética , Cadeias HLA-DRB1 , Haplótipos , Heterozigoto , Humanos , Masculino , Sistema de Registros/estatística & dados numéricos
9.
Tissue Antigens ; 76(2): 135-43, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20403144

RESUMO

Molecular analysis of genetic polymorphism for clinical or research purposes may be compromised by genomic DNA of limited quality and quantity. In this study, we have successfully tested the feasibility of using whole genome amplification (WGA) to allow genotyping for killer cell immunoglobulin-like receptor (KIR) genes and human leucocyte antigen (HLA)-C KIR ligand dimorphism on HLA-C. WGA was achieved by multiple displacement amplification (MDA) using bacteriophage phi29 polymerase. For KIR genotyping, a revised sequence-specific primer polymerase chain reaction protocol consisting of 23 primer pairs was used avoiding hitherto undetected cross-priming involving KIR2DL1, KIR2DS1, KIR3DL1 and KIR3DS1 alleles. Similarly, MDA-amplified genomic DNA was analyzed for the detection of the HLA-C KIR ligand groups C1 and C2, based on the amino acid K/N dimorphism in position 80.


Assuntos
Antígenos HLA-C/genética , Reação em Cadeia da Polimerase/métodos , Receptores KIR/genética , Alelos , Sequência de Bases , Primers do DNA/genética , Sondas de DNA de HLA/genética , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Ligantes , Polimorfismo de Nucleotídeo Único , Receptores KIR2DL1/genética , Receptores KIR3DL1/genética , Receptores KIR3DS1/genética
10.
Autoimmunity ; 42(4): 389-91, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19811310

RESUMO

Polymorphisms in the upstream regulatory region of the HLA class II DQA1 gene are currently defined by 10 different alleles. Two of them carrying a Y-box mutation are associated with susceptibility to oligoarticular juvenile idiopathic arthritis (OA-JIA). We investigated allele-dependent differences in HLA-DQA1 gene expression in OA-JIA patients. In cells from affected joints compared to peripheral blood, gene expression of HLA-DRA as well as total HLA-DQA1 was significantly upregulated. Differential analyses of HLA-DQA1 allelic expression showed DQA1*02 and *04 to be comparatively increased. Intra-articular upregulation of HLA-DQA1 was predominantly observed for the OA-JIA associated allele HLA-DQA1*04. Nevertheless, the Y-box mutation of the disease-associated allele DQA1*0401 was not a common denominator for expression behaviour.


Assuntos
Artrite Juvenil/genética , Predisposição Genética para Doença , Antígenos HLA-DQ/genética , Polimorfismo Genético , Expressão Gênica , Perfilação da Expressão Gênica , Cadeias alfa de HLA-DQ , Humanos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
11.
Minerva Cardioangiol ; 57(4): 511-20, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19763072

RESUMO

Cardiovascular magnetic resonance (CMR) is the gold standard for quantification of ventricular size, mass and function. Moreover, CMR can differentiate transient and permanent tissue damage. Therefore CMR is clinically useful to differentiate acute myocarditis from infarction. Various CMR markers for acute myocardial inflammation are reviewed. Moreover CMR can differentiate tissue changes in various nonischemic cardiomyopathies. This has a major clinical impact for diagnosis and risk stratification in these patients. Serial monitoring is feasible due to high reproducibility and the lack of radiation. The strengths and pitfalls in CMR imaging of nonischemic cardiomyopathies are reviewed in detail including an overview of the current literature.


Assuntos
Cardiomiopatias/diagnóstico , Imageamento por Ressonância Magnética , Miocardite/diagnóstico , Amiloidose/diagnóstico , Síndrome de Churg-Strauss/diagnóstico , Meios de Contraste , Diagnóstico Diferencial , Edema/diagnóstico , Doença de Fabry/diagnóstico , Estudos de Viabilidade , Feminino , Fibrose/diagnóstico , Humanos , Lúpus Eritematoso Sistêmico/diagnóstico , Imageamento por Ressonância Magnética/métodos , Masculino , Infarto do Miocárdio/diagnóstico , Sístole/fisiologia
12.
Lupus ; 17(6): 561-7, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18539710

RESUMO

Systemic lupus erythematosus (SLE) is a multi-organ inflammatory disorder mainly affecting women and is associated with high cardiovascular morbidity and mortality. We tested the utility of a comprehensive cardiovascular magnetic resonance approach to assess myocardial involvement and to determine its relation to disease activity in SLE patients. We studied 20 SLE patients (19 females, 35+/-10 years) and 13 healthy volunteers (nine females, 28+/-11 years). Classification followed the criteria of the American College of Rheumatology and assessment of SLE activity was based on the European Consensus Lupus Activity Measurement index. Cardiovascular magnetic resonance (CMR) was performed on a 1.5T scanner and included the following sequences: steady-state free precession, T2-weighted, early and late T1-weighted after gadolinium-DTPA injection. Ejection fraction was not significantly different between groups (controls: 63+/-6, inactive SLE: 67+/-7, active SLE 64+/-8; P=0.003 for all groups). In contrast, relative T2 ratio (myocardium to skeletal muscle) was significantly higher in active SLE than in the other groups (controls: 1.7+/-0.3, inactive: 1.8+/-0.2, active: 2.1+/-0.2; P=0.003). Similarly, early enhancement ratio was significantly higher in active SLE (controls: 2.4+/-1.4, inactive: 2.8+/-1.1, active: 4.5+/-2.0, P=0.39). Both relative T2 and early enhancement ratios significantly correlated with disease activity. Intramural foci of late enhancement were observed in three of eight patients (all with active SLE). Of the five patients with no late enhancement, only one had active disease. An imaging approach combining T2-weighted, early and late enhancement imaging is a useful tool to assess possible myocardial involvement in SLE. CMR parameters of global myocardial involvement correlate well with disease activity, but not with usual clinical signs as summarized in a cardiac score.


Assuntos
Lúpus Eritematoso Sistêmico/patologia , Miocárdio/patologia , Adolescente , Adulto , Feminino , Humanos , Lúpus Eritematoso Sistêmico/fisiopatologia , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Miocárdio/citologia , Miocárdio/metabolismo
14.
Diabetologia ; 48(9): 1830-2, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16010521

RESUMO

AIMS/HYPOTHESIS: Insulin autoantibodies (IAA) precede and predict the onset of type 1 diabetes, but not all children with IAA develop the disease. In affected families, IAA affinity can identify IAA-positive children who are more likely to progress to diabetes. The purpose of this study was to determine whether affinity is a useful marker to stratify type 1 diabetes risk in IAA-positive children from the general population. METHODS: IAA affinity was determined by competitive binding to 125I-insulin with increasing concentrations of cold insulin and with cold proinsulin in sera from 46 IAA-positive children identified in the Karlsburg Type 1 Diabetes Risk Study of a Normal Schoolchild Population in north-eastern Germany. RESULTS: IAA affinity ranged between 5 x 10(6) and 1.2 x 10(11) l/mol. IAA affinity was higher in 24 children who developed multiple islet autoantibodies or diabetes (median 3.5 x 10(9) l/mol; interquartile range [IQR] 2.1x10(9) to 2.1 x 10(10) l/mol) than in 22 children who did not develop multiple islet autoantibodies or diabetes (median 1.3 x 10(8) l/mol; IQR 3.8 x 10(7) to 7.2 x 10(8) l/mol; p<0.0001). Using a threshold of > or = 10(9) l/mol, 22 of the 24 children who developed multiple islet autoantibodies or diabetes were correctly identified by high-affinity IAA and 18 of 22 who did not develop multiple islet autoantibodies or diabetes were correctly identified by low-affinity IAA. IAA affinity was significantly higher in samples with proinsulin reactive IAA (p<0.0001). CONCLUSIONS/INTERPRETATION: IAA affinity measurement provides robust identification of IAA associated with high diabetes risk.


Assuntos
Autoanticorpos/sangue , Diabetes Mellitus Tipo 1/epidemiologia , Insulina/imunologia , Adolescente , Criança , Diabetes Mellitus Tipo 1/imunologia , Feminino , Seguimentos , Alemanha/epidemiologia , Humanos , Ilhotas Pancreáticas/imunologia , Masculino , Fatores de Risco
15.
Diabetologia ; 48(5): 922-30, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15834701

RESUMO

AIMS/HYPOTHESIS: Progression to type 1 diabetes is associated with intramolecular epitope spreading to disease-specific antibody epitopes located in the middle region of glutamic acid decarboxylase 65 (GAD65). METHODS: The relationship between intramolecular epitope spreading of autoantibodies specific to GAD65 in relation to the risk of developing type 1 diabetes was tested in 22 high-risk individuals and 38 low-risk individuals. We determined the conformational epitopes in this longitudinal study by means of competition experiments using recombinant Fab of four GAD65-specific monoclonal antibodies. RESULTS: Sera from high-risk children in the preclinical stage recognise a specific combination of GAD65 antibody epitopes located in the middle and the C-terminus of GAD65. High risk of progressing to disease is associated with the emergence of antibodies specific for conformational epitopes at the N-terminus and the middle region. Binding to already established antibody epitopes located in the middle and at the N-terminus increases and shows a significant relation (p=0.005) with HLA, which confers risk of developing diabetes. CONCLUSIONS/INTERPRETATION: In type 1 diabetes, GAD65 antibodies are initially generated against the middle and C-terminal regions of GAD65. In genetically predisposed subjects the autoimmune response may then undergo intramolecular epitope spreading towards epitopes on the N-terminus and further epitopes located in the middle. These findings clearly demonstrate that the GAD65 autoantibody response in the preclinical stage of type 1 diabetes is dynamic and related to the HLA genotypes that confer risk of diabetes. GAD65-specific Fab should prove useful in predicting progression from islet autoimmunity to clinical onset of type 1 diabetes.


Assuntos
Autoanticorpos/sangue , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/imunologia , Glutamato Descarboxilase/imunologia , Isoenzimas/imunologia , Adolescente , Criança , Epitopos/análise , Feminino , Genótipo , Antígenos HLA , Humanos , Fragmentos Fab das Imunoglobulinas/imunologia , Complexo Principal de Histocompatibilidade , Masculino , Fatores de Risco
16.
Tissue Antigens ; 65(4): 370-8, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15787721

RESUMO

The relevance of anti-HLA class II antibodies for kidney graft survival is still controversial. In part, this can be attributed to difficulties to detect and differentiate anti-HLA class II antibodies. Anti-HLA class II IgG antibody screening was performed by enzyme-linked immunosorbent assay. Subsequently, all anti-HLA class II-positive sera were subjected to the determination and specification using color-coded microspheres coated with purified HLA antigens. In a cohort of 934 patients awaiting kidney transplantation, 41 sera (4.4%) were positive for IgG anti-HLA class II antibodies. The presence was confirmed in 90.2% sera by retesting. Subsequently, all anti-HLA class II-positive patients (n = 27) who in the past had undergone a kidney transplantation with an HLA-DR and/or -DQ-mismatched graft were selected. In 25 of 27 sera (92.6%), the alloantibody specificities corresponded to the known previous transplant mismatches on a broad antigen level. In 20 of 27 sera (74.1%), anticlass I antibodies were detected as well. Anti-HLA-DP antibodies were seen in 24 of the 27 sera of this cohort. In the majority of the cases, the reactivities with different DPB1 alleles could be explained by involvement of a single, specific DPB1 epitope. Donor-specific anti-HLA-DR and -DQ antibodies were seen in the majority of cases with graft failure following HLA class II alloantigen exposure in prior kidney transplantations. In addition, HLA-DP may serve as a transplantation antigen in kidney transplantation, leading to a humoral response.


Assuntos
Antígenos HLA-D/imunologia , Isoanticorpos/imunologia , Transplante de Rim , Ensaio de Imunoadsorção Enzimática , Humanos , Reoperação , Doadores de Tecidos
17.
Ann Rheum Dis ; 64(3): 457-61, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15708894

RESUMO

BACKGROUND: Cytokines and T cell regulatory proteins play an important role in the pathogenesis of Wegener's granulomatosis (WG). OBJECTIVE: To investigate cytokine and cytotoxic T cell antigen-4 (CTLA4) gene polymorphisms and HLA class II alleles in generalised WG. METHODS: The distribution of cytokine and cytotoxic T cell antigen 4 (CTLA4) gene polymorphisms and HLA class II alleles was analysed in 32 patients with generalised WG and 91 healthy controls. Genotyping was carried out for HLA-DRB1 and HLA-DQB1 and for polymorphism of the genes encoding TNF alpha (-238, -308, -376), TGF beta (codon 10 and 25), IFN gamma (+874), IL6 (-174), IL10 (-592, -819, -1082), CTLA4 (-318, +49), and the (AT)(n) repeats of the CTLA4 gene. In addition, stratification analysis was carried out according to the presence (n = 15) or absence (n = 17) of end stage renal disease. RESULTS: An increase in the IFN gamma +874 T/T (odds ratio (OR) = 3.14) and TNF alpha -238 G/A (OR = 5.01) genotypes was found in WG patients. When ESRD positive and negative patients were compared, the IFN gamma +874 A/A and the CTLA4 -318 C/C genotypes were found more often in the ESRD subgroup (OR = 10.6 and OR = 2.25). WG patients without ESRD had a higher frequency of the IL10 GCC/ACC promotor genotype (OR = 0.13) and long CTLA4 (AT)(n) repeats (OR = 0.4). No effect was seen for HLA-DR and -DQ markers. CONCLUSIONS: Disease susceptibility and clinical course in WG may be associated with distinct polymorphisms of cytokine and CTLA4 genes.


Assuntos
Antígenos de Diferenciação/genética , Citocinas/genética , Granulomatose com Poliangiite/genética , Falência Renal Crônica/genética , Polimorfismo Genético , Adulto , Idoso , Antígenos CD , Antígeno CTLA-4 , Predisposição Genética para Doença , Genótipo , Granulomatose com Poliangiite/imunologia , Antígenos HLA-DQ , Cadeias beta de HLA-DQ , Antígenos HLA-DR , Cadeias HLA-DRB1 , Humanos , Interferon gama/genética , Interleucina-10/genética , Falência Renal Crônica/imunologia , Pessoa de Meia-Idade , Fator de Necrose Tumoral alfa/genética
18.
Tissue Antigens ; 64(1): 13-7, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15191518

RESUMO

The use of allogeneic venous grafts from postmortal organ donors allows for the reconstruction of critically affected arteries in patients with peripheral occlusive vascular disease. We were interested to determine the prevalence and specificity of anti-HLA antibodies in patients after allogeneic vein transplantation. Anti-HLA class I and II alloantibodies were analyzed by flowcytometric analysis using color-coded microbeads coated with HLA antigens including recombinant single antigens. Nine out of 10 patients involving 12 venous allografts were positive for anti-HLA alloantibodies. All antibody-positive patients carried both anti-HLA class I and II alloantibodies. Anti-donor HLA specificity of the anti-HLA alloantibodies was seen in seven out of nine patients for anti-class I antibodies and in eight out of nine patients for anti-HLA class II antibodies. A high rate of donor-specific allosensitization was seen after allogeneic venous transplantation. In conclusion, allosensitization not only includes a humoral response against the constitutively expressed class I antigens but also extends to class II antigens.


Assuntos
Arteriopatias Oclusivas/imunologia , Arteriopatias Oclusivas/cirurgia , Bioprótese/efeitos adversos , Prótese Vascular/efeitos adversos , Isoanticorpos/sangue , Idoso , Idoso de 80 Anos ou mais , Especificidade de Anticorpos , Cadáver , Feminino , Antígenos HLA , Antígenos de Histocompatibilidade Classe I , Antígenos de Histocompatibilidade Classe II , Humanos , Masculino , Pessoa de Meia-Idade , Doadores de Tecidos , Transplante Homólogo
19.
Genes Immun ; 5(5): 405-16, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15175648

RESUMO

In addition to coding region polymorphism, allele-specific variation in the upstream regulatory region of the HLA-DQB1 gene has been detected. Reporter gene assays and transfection studies have indicated that HLA-DQB1 promoter polymorphism may be of functional significance. The aim of this study was to utilize real-time reverse transcriptase-polymerase chain reaction (RT-PCR) for allele-specific quantification of HLA-DQB1 expression and to analyze cell-specific HLA-DQB1 expression in vivo. For the allele-specific quantification of DQB1 gene products, a real-time RT-PCR set of primer pairs (n=27) and probes (n=5) targeting exon 2 variability was established. The robustness and integrity of the assay system were confirmed by using recombinant DQB1 exon 2 plasmid clones as active exogenous controls. Sensitivity and reproducibility were assessed by serial dilution and allelic mixing analyses. In application to the study of allele-specific expression of DQB1 gene products during cytokine-driven maturation of monocyte-derived dendritic cells, differential patterns of allelic expression in heterozygous individuals were observed for DQB1*0301, compared to DQB1*0501 and DQB1*0602. At maximum, 1.9-fold (*0301/*0501) and 2.5-fold (*0301/*0602) higher induction was seen for DQB*0301. In conclusion, HLA-DQB1 expression can be analyzed by real-time RT-PCR suitable for cell- and allele-specific detection of HLA-DQB1 transcripts in homo- and heterozygous combinations.


Assuntos
Alelos , Antígenos HLA-DQ/genética , Polimorfismo Genético , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sequência de Bases , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Citocinas/farmacologia , Células Dendríticas/metabolismo , Expressão Gênica , Frequência do Gene/genética , Antígenos HLA-DQ/biossíntese , Cadeias beta de HLA-DQ , Heterozigoto , Humanos , Dados de Sequência Molecular , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Regiões Promotoras Genéticas/genética
20.
Chirurg ; 75(2): 153-9, 2004 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-14991177

RESUMO

Allogenic venous transplantation represents an alternative procedure for preventing leg amputation. This study reviewed the question of whether immunologic monitoring and immunosuppressive therapy provide results close to those of autologous reconstructions. Twenty-eight patients received 31 homologous venous transplants. The average age in this group of 15 women and 13 men was 64.5 years. Limbs in danger of amputation could be kept longer in two thirds of them. These promising results show the superiority of this method over the use of alloplastic material in regions with cruropedal vessels. Therefore, it can be recommended in acute leg ischemia with lack of autologous vascularity. Improving guidelines for indication will be an interesting research field, and more contributions are needed.


Assuntos
Arteriopatias Oclusivas/cirurgia , Pé/irrigação sanguínea , Imunossupressores/uso terapêutico , Isquemia/cirurgia , Salvamento de Membro , Veias/transplante , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Transplante Homólogo
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