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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Envolvimento do sistema imune na Doença de Gaucher : análise de variantes dos genes HLA e KIR

Vairo, Filippo Pinto e January 2012 (has links)
Introdução: A Doença de Gaucher (DG) é causada pela atividade reduzida da enzima lisossomal glucocerebrosidase, o que leva ao acúmulo de glicocerebrosídeo nas células e a uma estimulação crônica do sistema imune. Células natural killer (NK) possuem um papel importante na resposta imune e sua atividade é alterada na DG. Os receptores KIR (Killer Immunoglobulin-like Receptors) regulam a atividade das células NK através da interação com moléculas de HLA (Human Leukocyte Antigen) de classe I das célulasalvo. Objetivo: Analisar a variabilidade dos genes KIR em uma coorte de pacientes com DG do Sul do Brasil, compará-las a um grupo controle e buscar associações com manifestações clínicas. Metodologia: Trinta e um pacientes com DG tipo I (24 com forma leve, 4 com forma moderada e 3 com forma grave) foram analisados e comparados a 250 controles saudáveis quanto a frequência dos genes HLA e KIR. Resultados/Discussão: Não houve diferença significativa nas frequências de variantes dos genes KIR entre os grupos. O alelo HLA B37 é mais frequente nos pacientes com DG do que no grupo controle (p=0,011). A idade de início dos sintomas mostrou associação com a combinação das variantes KIR2DL2 e KIR2DS2 com seu ligante HLA-C1 (p=0,038). Pacientes que apresentam a variante HLA-C2 parecem apresentar maior susceptibilidade a desenvolver bandas mono ou policlonais na eletroforese de proteínas (p=0,007, OR=21,3). Foi encontrada associação entre os alelos DR11 (p=0.008) e DR13 (p=0.011) e gravidade da doença. O alelo DR11 parece estar associado a comprometimento neurológico, enquanto o alelo DR13 ao desenvolvimento de osteonecrose. Conclusão: Nossos dados sugerem uma possível associação entre variantes dos genes KIR e HLA e a DG. Devem ser estudadas em outras coortes de pacientes já que parecem ser um fator modificador de fenótipo. / Background: Gaucher disease (GD) is caused by the reduced activity of a lysosomal enzyme glucocerebrosidase, which leads to the accumulation of glucocerebroside in the cells and a chronic stimulation of the immune system. Natural Killer (NK) cells play an important role in the immune response, and their activity is impaired in GD. Killer immunoglobulin-like receptors (KIR) regulate the activity of NK cells through an interaction with specific human leukocyte antigen (HLA) class I molecules on target cells. Objectives: To analyze the variability of KIR genes in a Southern Brazilian sample of GD patients, to compare it with controls, and to look for associations with clinical manifestations. Methodology: Thirty one GD type I patients (24 mild, 4 moderate, and 3 severe) were analyzed and compared to 250 healthy controls regarding the frequency of HLA and KIR genes. Results/Discussion: There was no significative difference in the frequencies of KIR gene variants between the groups. The HLA B37 allele is more frequent in patients with GD than in control group (p=0.011). The age of onset of symptoms was associated with KIR2DL2 and KIR2DS2 combination with the ligand HLA-C1 (p=0.038). Patients who have the HLA-C2 variant appear to have more mono/polyclonal bands in protein electrophoresis (p=0.007, OR=21.3). An association between the DR11 (p=0.008) and DR13 (p=0.011) alleles and disease severity was found. The DR11 allele appears to be associated with neurological impairment, while the DR13 allele to the development of osteonecrosis. Conclusion: Our data suggest a possible association between KIR genes and HLA genes and GD. They should be studied in other cohorts of GD patients as they seem to be a phenotype modifying factor.
212

Variação genética do éxon 8 de HLA-G em pacientes críticos

Graebin, Pietra January 2012 (has links)
Pacientes críticos são indivíduos internados em Unidades de Terapia Intensiva (UTI) e se caracterizam por apresentar um quadro patológico crítico e complexo, decorrente de fragilidades fisiológicas graves, podendo evoluir para sepse, sepse severa, choque séptico ou óbito. Muitos recursos financeiros são investidos no controle da sepse em hospitais públicos e privados, e a sepse é a maior causa de morte entre as UTIs brasileiras. O desfecho de um paciente crítico é influenciado por vários fatores, entre eles, os genéticos. A molécula HLA-G apresenta variabilidade proteica limitada e expressão tecidual restrita. A interação entre moléculas de HLA-G e os receptores KIR e LILR desencadeia diversas atividades imunomodulatórias. Na região 3’ UTR localizam-se os polimorfismos +2960INDEL, +3142C>G e +3187A>G que podem regular a expressão de HLA-G. Até o momento, apenas um estudo investigou a expressão de sHLA-G5 em pacientes críticos com choque séptico, e se observou que o aumento dos níveis de sHLA-G5 foram preditivos de sobrevivência entre os pacientes que evoluíram para choque séptico. O objetivo do presente trabalho foi determinar as frequências alélicas do polimorfismo +2960INDEL e dos seguintes SNPs: +3003C>T, +3010C>G, +3027A>C,+3142 C>G e +3187A>G, bem como avaliar a influência dessas variantes na evolução para sepse, choque séptico e óbito entre pacientes críticos. Foram analisadas 698 amostras provenientes de pacientes críticos do Hospital São Lucas – PUCRS. O éxon 8 da região 3’ UTR foi amplificado por PCR e encaminhado para sequenciamento direto (ABI 3730 XL DNA Sequencer). A inferência haplotípica foi determinada pelo software PHASE versão 2.1. A frequência haplotípica, desequilíbrio de ligação (DL), Equilíbrio De Hardy-Weinberg (EHW) e teste de heterozigosidade foram estimados pelo software ARLEQUIN versão 3.5. Os dados foram submetidos ao pacote estatístico SPSS versão 18.0. Observaram-se as seguintes frequências alélicas e genotípicas, respectivamente: +2960INDEL, DEL= 0,578 e IN= 0,421, DELDEL= 0,310, DELIN= 0,536 e ININ= 0,152; +3003C>T, C= 0,109 e T= 0,890, CC= 0,012, CT= 0,194 e TT= 0,793; +3010C>G, CC= 0,521 e G= 0,478, CC= 0,250, CG= 0,540 e GG= 0,208; +3027A>C, A= 0,034 e C= 0,965, AA= 0,001, AC= 0,006 e CC= 0,932; +3035C>T, C= 0,861 e T= 0,141, CC= 0,733, CT= 0,255 e TT= 0,010; +3142C>G, C= 0,463 e G= 0,536, CC= 0,180, CG= 0,565 e GG= 0,253 e +3187A>G, A= 0,699 e G= 0,304, AA= 0,448, AG= 0,503 e GG= 0,048. Os polimorfismos +2960INDEL, +3010C>G, +3142C>G e +3187A>G não corresponderam ao EHW e apresentaram heterozigosidade observada maior do que a esperada. Os dois haplótipos mais frequentes foram DTGCCCG (27,90%) e ITCCCGA (26,65%), confirmando a heterogeneidade da população brasileira. A região 3’ UTR está sob seleção balanceadora, em que a seleção dos heterozigotos pode ser vantajosa, permitindo o balanço entre altas e baixas expressões de HLA-G, conforme o contexto biológico. Todos os sítios polimórficos apresentaram forte DL entre si. Entre os pacientes críticos que evoluíram para sepse, observou-se uma associação entre os portadores do alelo +2960IN e choque séptico (Chi-Square, p= 0,036). Entre os pacientes críticos, observou-se uma associação entre os portadores do haplótipo +2960IN_+3142G_+3187A e choque séptico (Chi-Square, p=0,038). E os pacientes críticos com sepse e portadores do haplótipo +2960IN_+3142G_+3187A (Chi-Square, p=0,023) também foram mais suscetíveis a evoluírem para choque séptico. Observou-se, pela primeira vez, uma associação entre o haplótipo +2960IN_+3142G_+3187A e os desfechos de pacientes críticos. Mais estudos são necessários para confirmação desses resultados e outros parâmetros poderiam ser considerados, como níveis de IL-10 e glicocorticóides endógenos, além do perfil de citocinas liberado por pacientes críticos. Devido às propriedades imunomodulatórias descritas para a molécula de HLA-G, futuramente os seus polimorfismos e sua expressão poderiam ser empregadas em abordagens clínicas nos mais variados contextos imunológicos. A amostra estudada está de acordo com as freqüências alélicas, genotípicas e haplotípicas observadas na população brasileira e novos polimorfismos poderiam ser investigados no éxon 8 da região 3’ UTR do HLA-G. / Critically ill patients are individuals hospitalized in Intensive Care Units (ICU) and are characterized by presenting pathologic complex conditions due to serious physiological weaknesses that may evolve to sepsis, septic shock or even death. Massive resources have been invested in sepsis control both in public and private sectors, although sepsis is still the major cause of death in Brazilians ICUs. Several factors influence the outcome of a critically ill patient, including genetic factors. HLA-G molecule is characterized by limited protein variability and restricted tissue expression. HLA-G binding to KIR and LILR receptors triggers various immunoregulatory activities. The HLA-G gene 3’ UTR presents a 14 bp insertion/deletion at +2960, a SNP at +3142C>G and a SNP at +3187A>G that may regulate HLA-G expression. So far, only one study has investigated HLA-G expression in critically ill patients with septic shock, observing that increased sHLA-G5 levels were predictive of survival among septic shock patients. The aim of this study was to assess the frequencies of 14 pb insertion/deletion polymorphism at +2960INDEL, and the followings SNPs: +3003C>T, +3010C>G, +3027A>C, +3035C>T, +3142C>G and +3187A>G in exon 8 at the 3’ UTR of the HLA-G gene and correlate these variants with different clinical outcomes in critically ill patients. 698 samples were obtained from ICU patients from São Lucas-PUCRS Hospital and the exon 8 at the 3’ UTR of the HLA-G gene was sequenced. The haplotype inference was determinated by PHASE version 2.1 software. Haplotype frequency, linkage disequilibrium (LD), Hardy-Weinberg Equilibrium (HWE) and heterozigosity test were estimated by ARLEQUIN version 3.5 software. The data were submitted to the package SPSS version 18.0 software. The followings allelic and genotypic frequencies were observed, respectively: +2960INDEL, DEL= 0.578 and IN= 0.421, DELDEL= 0.310, DELIN= 0.536 and ININ= 0.152; +3003C>T, C= 0.109 and T= 0.890, CC= 0.012, CT= 0.194 and TT= 0.793; +3010C>G, CC= 0.521 and G= 0.478, CC= 0.250, CG= 0.540 and GG= 0.208; +3027A>C, A= 0.034 and C= 0.965, AA= 0.001, AC= 0.006 and CC= 0.932; +3035C>T, C= 0.861 and T= 0.141, CC= 0.733, CT= 0.255 and TT= 0.010; +3142C>G, C= 0.463 and G= 0.536, CC= 0.180, CG= 0.565 and GG= 0.253 and +3187A>G, A= 0.699 and G= 0.304, AA= 0.448, AG= 0.503 and GG= 0.048. The +2960INDEL, +3010C>G, +3142C>G and +3187A>G polymorphisms were not on HWE and had higher observed heterozygosity than expected. The two most frequent haplotypes were DTGCCCG (27.90%) and ITCCCGA (26.65%). The Brazilian population is a heterogeneous population, and these data agree with this statement. The 3’ UTR is under balancing selection and heterozygote selection is advantageous, allowing the balance between high and low expression of HLA-G, according to the biological context. All polymorphic sites showed strong LD between them. Among critically ill patients who developed sepsis, there was an association between the allele +2960IN and septic shock (Chi-Square, p = 0.036). Among all critically ill patients, there was an association between carriers of the haplotype +2960IN_+3142 G_+3187A and septic shock (Chi-Square, p = 0.038). Critically ill patients with sepsis who carrier the haplotype +2960IN_+3142 G_+3187A were also more susceptible to progression to septic shock (Chi-Square, p = 0.023). For the first time, an association between +2960IN_+3142G_+3187A haplotype and outcomes of critically ill patients was observed. More studies are needed to confirm these results and other parameters could be considered, as IL-10 and endogenous glucocorticoids levels and cytokine profile released by critically ill patients. Because of the immunomodulatory properties described for the HLA-G molecule, in future its polymorphisms and its expression could be used in clinical approaches in various immune contexts. These results are according to allelic, genotypic and haplotypic frequencies observed in Brazilian population, and new polymorphisms could be investigated in exon 8 at the 3 'UTR of HLA-G gene.
213

Envolvimento do sistema imune na Doença de Gaucher : análise de variantes dos genes HLA e KIR

Vairo, Filippo Pinto e January 2012 (has links)
Introdução: A Doença de Gaucher (DG) é causada pela atividade reduzida da enzima lisossomal glucocerebrosidase, o que leva ao acúmulo de glicocerebrosídeo nas células e a uma estimulação crônica do sistema imune. Células natural killer (NK) possuem um papel importante na resposta imune e sua atividade é alterada na DG. Os receptores KIR (Killer Immunoglobulin-like Receptors) regulam a atividade das células NK através da interação com moléculas de HLA (Human Leukocyte Antigen) de classe I das célulasalvo. Objetivo: Analisar a variabilidade dos genes KIR em uma coorte de pacientes com DG do Sul do Brasil, compará-las a um grupo controle e buscar associações com manifestações clínicas. Metodologia: Trinta e um pacientes com DG tipo I (24 com forma leve, 4 com forma moderada e 3 com forma grave) foram analisados e comparados a 250 controles saudáveis quanto a frequência dos genes HLA e KIR. Resultados/Discussão: Não houve diferença significativa nas frequências de variantes dos genes KIR entre os grupos. O alelo HLA B37 é mais frequente nos pacientes com DG do que no grupo controle (p=0,011). A idade de início dos sintomas mostrou associação com a combinação das variantes KIR2DL2 e KIR2DS2 com seu ligante HLA-C1 (p=0,038). Pacientes que apresentam a variante HLA-C2 parecem apresentar maior susceptibilidade a desenvolver bandas mono ou policlonais na eletroforese de proteínas (p=0,007, OR=21,3). Foi encontrada associação entre os alelos DR11 (p=0.008) e DR13 (p=0.011) e gravidade da doença. O alelo DR11 parece estar associado a comprometimento neurológico, enquanto o alelo DR13 ao desenvolvimento de osteonecrose. Conclusão: Nossos dados sugerem uma possível associação entre variantes dos genes KIR e HLA e a DG. Devem ser estudadas em outras coortes de pacientes já que parecem ser um fator modificador de fenótipo. / Background: Gaucher disease (GD) is caused by the reduced activity of a lysosomal enzyme glucocerebrosidase, which leads to the accumulation of glucocerebroside in the cells and a chronic stimulation of the immune system. Natural Killer (NK) cells play an important role in the immune response, and their activity is impaired in GD. Killer immunoglobulin-like receptors (KIR) regulate the activity of NK cells through an interaction with specific human leukocyte antigen (HLA) class I molecules on target cells. Objectives: To analyze the variability of KIR genes in a Southern Brazilian sample of GD patients, to compare it with controls, and to look for associations with clinical manifestations. Methodology: Thirty one GD type I patients (24 mild, 4 moderate, and 3 severe) were analyzed and compared to 250 healthy controls regarding the frequency of HLA and KIR genes. Results/Discussion: There was no significative difference in the frequencies of KIR gene variants between the groups. The HLA B37 allele is more frequent in patients with GD than in control group (p=0.011). The age of onset of symptoms was associated with KIR2DL2 and KIR2DS2 combination with the ligand HLA-C1 (p=0.038). Patients who have the HLA-C2 variant appear to have more mono/polyclonal bands in protein electrophoresis (p=0.007, OR=21.3). An association between the DR11 (p=0.008) and DR13 (p=0.011) alleles and disease severity was found. The DR11 allele appears to be associated with neurological impairment, while the DR13 allele to the development of osteonecrosis. Conclusion: Our data suggest a possible association between KIR genes and HLA genes and GD. They should be studied in other cohorts of GD patients as they seem to be a phenotype modifying factor.
214

Variação genética do éxon 8 de HLA-G em pacientes críticos

Graebin, Pietra January 2012 (has links)
Pacientes críticos são indivíduos internados em Unidades de Terapia Intensiva (UTI) e se caracterizam por apresentar um quadro patológico crítico e complexo, decorrente de fragilidades fisiológicas graves, podendo evoluir para sepse, sepse severa, choque séptico ou óbito. Muitos recursos financeiros são investidos no controle da sepse em hospitais públicos e privados, e a sepse é a maior causa de morte entre as UTIs brasileiras. O desfecho de um paciente crítico é influenciado por vários fatores, entre eles, os genéticos. A molécula HLA-G apresenta variabilidade proteica limitada e expressão tecidual restrita. A interação entre moléculas de HLA-G e os receptores KIR e LILR desencadeia diversas atividades imunomodulatórias. Na região 3’ UTR localizam-se os polimorfismos +2960INDEL, +3142C>G e +3187A>G que podem regular a expressão de HLA-G. Até o momento, apenas um estudo investigou a expressão de sHLA-G5 em pacientes críticos com choque séptico, e se observou que o aumento dos níveis de sHLA-G5 foram preditivos de sobrevivência entre os pacientes que evoluíram para choque séptico. O objetivo do presente trabalho foi determinar as frequências alélicas do polimorfismo +2960INDEL e dos seguintes SNPs: +3003C>T, +3010C>G, +3027A>C,+3142 C>G e +3187A>G, bem como avaliar a influência dessas variantes na evolução para sepse, choque séptico e óbito entre pacientes críticos. Foram analisadas 698 amostras provenientes de pacientes críticos do Hospital São Lucas – PUCRS. O éxon 8 da região 3’ UTR foi amplificado por PCR e encaminhado para sequenciamento direto (ABI 3730 XL DNA Sequencer). A inferência haplotípica foi determinada pelo software PHASE versão 2.1. A frequência haplotípica, desequilíbrio de ligação (DL), Equilíbrio De Hardy-Weinberg (EHW) e teste de heterozigosidade foram estimados pelo software ARLEQUIN versão 3.5. Os dados foram submetidos ao pacote estatístico SPSS versão 18.0. Observaram-se as seguintes frequências alélicas e genotípicas, respectivamente: +2960INDEL, DEL= 0,578 e IN= 0,421, DELDEL= 0,310, DELIN= 0,536 e ININ= 0,152; +3003C>T, C= 0,109 e T= 0,890, CC= 0,012, CT= 0,194 e TT= 0,793; +3010C>G, CC= 0,521 e G= 0,478, CC= 0,250, CG= 0,540 e GG= 0,208; +3027A>C, A= 0,034 e C= 0,965, AA= 0,001, AC= 0,006 e CC= 0,932; +3035C>T, C= 0,861 e T= 0,141, CC= 0,733, CT= 0,255 e TT= 0,010; +3142C>G, C= 0,463 e G= 0,536, CC= 0,180, CG= 0,565 e GG= 0,253 e +3187A>G, A= 0,699 e G= 0,304, AA= 0,448, AG= 0,503 e GG= 0,048. Os polimorfismos +2960INDEL, +3010C>G, +3142C>G e +3187A>G não corresponderam ao EHW e apresentaram heterozigosidade observada maior do que a esperada. Os dois haplótipos mais frequentes foram DTGCCCG (27,90%) e ITCCCGA (26,65%), confirmando a heterogeneidade da população brasileira. A região 3’ UTR está sob seleção balanceadora, em que a seleção dos heterozigotos pode ser vantajosa, permitindo o balanço entre altas e baixas expressões de HLA-G, conforme o contexto biológico. Todos os sítios polimórficos apresentaram forte DL entre si. Entre os pacientes críticos que evoluíram para sepse, observou-se uma associação entre os portadores do alelo +2960IN e choque séptico (Chi-Square, p= 0,036). Entre os pacientes críticos, observou-se uma associação entre os portadores do haplótipo +2960IN_+3142G_+3187A e choque séptico (Chi-Square, p=0,038). E os pacientes críticos com sepse e portadores do haplótipo +2960IN_+3142G_+3187A (Chi-Square, p=0,023) também foram mais suscetíveis a evoluírem para choque séptico. Observou-se, pela primeira vez, uma associação entre o haplótipo +2960IN_+3142G_+3187A e os desfechos de pacientes críticos. Mais estudos são necessários para confirmação desses resultados e outros parâmetros poderiam ser considerados, como níveis de IL-10 e glicocorticóides endógenos, além do perfil de citocinas liberado por pacientes críticos. Devido às propriedades imunomodulatórias descritas para a molécula de HLA-G, futuramente os seus polimorfismos e sua expressão poderiam ser empregadas em abordagens clínicas nos mais variados contextos imunológicos. A amostra estudada está de acordo com as freqüências alélicas, genotípicas e haplotípicas observadas na população brasileira e novos polimorfismos poderiam ser investigados no éxon 8 da região 3’ UTR do HLA-G. / Critically ill patients are individuals hospitalized in Intensive Care Units (ICU) and are characterized by presenting pathologic complex conditions due to serious physiological weaknesses that may evolve to sepsis, septic shock or even death. Massive resources have been invested in sepsis control both in public and private sectors, although sepsis is still the major cause of death in Brazilians ICUs. Several factors influence the outcome of a critically ill patient, including genetic factors. HLA-G molecule is characterized by limited protein variability and restricted tissue expression. HLA-G binding to KIR and LILR receptors triggers various immunoregulatory activities. The HLA-G gene 3’ UTR presents a 14 bp insertion/deletion at +2960, a SNP at +3142C>G and a SNP at +3187A>G that may regulate HLA-G expression. So far, only one study has investigated HLA-G expression in critically ill patients with septic shock, observing that increased sHLA-G5 levels were predictive of survival among septic shock patients. The aim of this study was to assess the frequencies of 14 pb insertion/deletion polymorphism at +2960INDEL, and the followings SNPs: +3003C>T, +3010C>G, +3027A>C, +3035C>T, +3142C>G and +3187A>G in exon 8 at the 3’ UTR of the HLA-G gene and correlate these variants with different clinical outcomes in critically ill patients. 698 samples were obtained from ICU patients from São Lucas-PUCRS Hospital and the exon 8 at the 3’ UTR of the HLA-G gene was sequenced. The haplotype inference was determinated by PHASE version 2.1 software. Haplotype frequency, linkage disequilibrium (LD), Hardy-Weinberg Equilibrium (HWE) and heterozigosity test were estimated by ARLEQUIN version 3.5 software. The data were submitted to the package SPSS version 18.0 software. The followings allelic and genotypic frequencies were observed, respectively: +2960INDEL, DEL= 0.578 and IN= 0.421, DELDEL= 0.310, DELIN= 0.536 and ININ= 0.152; +3003C>T, C= 0.109 and T= 0.890, CC= 0.012, CT= 0.194 and TT= 0.793; +3010C>G, CC= 0.521 and G= 0.478, CC= 0.250, CG= 0.540 and GG= 0.208; +3027A>C, A= 0.034 and C= 0.965, AA= 0.001, AC= 0.006 and CC= 0.932; +3035C>T, C= 0.861 and T= 0.141, CC= 0.733, CT= 0.255 and TT= 0.010; +3142C>G, C= 0.463 and G= 0.536, CC= 0.180, CG= 0.565 and GG= 0.253 and +3187A>G, A= 0.699 and G= 0.304, AA= 0.448, AG= 0.503 and GG= 0.048. The +2960INDEL, +3010C>G, +3142C>G and +3187A>G polymorphisms were not on HWE and had higher observed heterozygosity than expected. The two most frequent haplotypes were DTGCCCG (27.90%) and ITCCCGA (26.65%). The Brazilian population is a heterogeneous population, and these data agree with this statement. The 3’ UTR is under balancing selection and heterozygote selection is advantageous, allowing the balance between high and low expression of HLA-G, according to the biological context. All polymorphic sites showed strong LD between them. Among critically ill patients who developed sepsis, there was an association between the allele +2960IN and septic shock (Chi-Square, p = 0.036). Among all critically ill patients, there was an association between carriers of the haplotype +2960IN_+3142 G_+3187A and septic shock (Chi-Square, p = 0.038). Critically ill patients with sepsis who carrier the haplotype +2960IN_+3142 G_+3187A were also more susceptible to progression to septic shock (Chi-Square, p = 0.023). For the first time, an association between +2960IN_+3142G_+3187A haplotype and outcomes of critically ill patients was observed. More studies are needed to confirm these results and other parameters could be considered, as IL-10 and endogenous glucocorticoids levels and cytokine profile released by critically ill patients. Because of the immunomodulatory properties described for the HLA-G molecule, in future its polymorphisms and its expression could be used in clinical approaches in various immune contexts. These results are according to allelic, genotypic and haplotypic frequencies observed in Brazilian population, and new polymorphisms could be investigated in exon 8 at the 3 'UTR of HLA-G gene.
215

Genotipagem na artrite reumatoide. Alelos HLA-classe II : HLA-DRB1 *0101 e *0102 associados a suscetibilidade e HLA-DRB1 *0401 e *0404 associados a agressividade

Bértolo, Manoel Barros, 1955- 20 September 1996 (has links)
Orientadores: Lilian Tereza Lavras Costallat, Fernando Ferreira Costa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-07-21T16:00:30Z (GMT). No. of bitstreams: 1 Bertolo_ManoelBarros_D.pdf: 5744580 bytes, checksum: f7167e9a18551a891129b8899097c781 (MD5) Previous issue date: 1996 / Resumo: A associação de antígenos de histocompatibilidade com a artrite reumatóide (AR) vem sendo demonstrada em inúmeros estudos. A principal associação em população caucasóide é com o HLA-DR4, contudo, também vem sendo observada com HLA-DRl e outros antígenos. Resultados de vários trabalhos sugerem que, o HLA-DR4 está mais associado com a gravidade do que com suscetibilidade. Com a introdução das técnicas de biologia molecular foi possível determinar que, os subtipos do HLA-DR4, relacionados com AR, são os alelos HLA-DRBl *0401, *0404 e *0405, que estão mais associados à gravidade da doença do que com a suscetibilidade. Em alguns estudos verificou-se, também, que os subtipos do HLA-DRl associados com a doença são os alelos HLA DRBl *0101 e *0102. Os propósitos deste estudo foram os de analisar a freqüência dos antígenos HLA-DR, identificar os alelos específicos do HLA-DRB 1, determinar sua freqüência, correlacionar estes alelos com as manifestações clínicas e laboratoriais e caracterizar aqueles que podem predizer o padrão evolutivo da AR em pacientes caucasóides. Foram avaliados 65 pacientes caucasóides, com AR, diagnosticados pelos critérios. da "American College of Rheumatism" (ACR). Todos foram avaliados clinicamente quanto ao envolvimento articular e extra-articular. O quadro funcional foi analisado usando-se a classificação funcional de Steinbrocker (CFS). Fator reumatóide (FR) e exame radiográfico foram realizados em todos os pacientes. Na determinação dos antígenos de classe I e TI utilizou-se a reação da microlinfocitotoxicidade. O DNA genômico dos pacientes positivos para HLA-DRl e DR4 foi amplificado pela reação da cadeia da polimerase (PCR), e a identificação dos alelos efetuada através da hibridização de sondas de oligonucleotídeos com seqüências específicas (SSO). Nesta casuística, o HLA mais freqüente foi o HLA-DRl (26,2%), quando comparado com o grupo controle (11,5%) (p<0,05). HLA-DR4 ocorreu em 24,6% dos pacientes e em 18% dos controles (p>0,05). Os pacientes com HLA-DRl não mostraram associação com nenhuma das variáveis clínicas e laboratoriais estudadas. Aqueles com DR4 positivo, quando comparados com DR4 negativo, apresentaram maiores títulos de FR, erosão óssea e um pior grau na CFS (p<0,05). Os alelos HLA-DRBI *0401 e *0404 apresentaram associação com um quadro funcional mais incapacitante, FR em altos títulos e erosão óssea, não se evidenciando predomínio significativo de um sobre o outro, com exceção do Fator Reumatóide, que estava em maiores títulos nos pacientes com o alelo *0404. Os alelos HLA-DRBI *0101 e *0102, embora mais freqüentes, não apresentaram associação com as variáveis clínicas e laboratoriais. Os pacientes com HLA-DRBI *0401, *0404 e *0101, que possuem seqüências semelhantes de aminoácidos na região 70-74 (QKRRA - QRRAA), mostraram maior freqüência de erosões. A partir dos dados obtidos, concluímos que os alelos HLA-DRBI *0101 e *0102 estavam relacionados com a suscetibilidade na AR, enquanto que os alelos HLA-DRB 1 *0401 e *0404 estavam associados com doença mais agressiva / Abstract: Several reports have shown that rheumatoid arthritis (RA) is associated with HLA-DR4, however association of RA and HLA-DRI has been found also in caucasian population. Subsets of HLA-DR4 were recognized using molecular biology technics. It has been mentioned that DR4 aneles (HLA-DRB 1 *0401, *0404, *0405) are more associated with severity than susceptibility to the disease. Our goals were to determine the HLA-DR frequency, to identify the specifics alleles of HLA-DRBI, to correlate these aneles with the clinical and laboratorial manifestations and to determine the aneles that can identify patients with more aggressive disease in caucasian with rheumatoid arthritis. Sixty five caucasian patients with RA (ACR's criteria) were analyzed with clinical, serological, radiographic data and functional status according to the Steinbrocker scale. To determine Class I and 11 antigens the microlinfocitotoxicity reaction was employed. Genomic DNA from HLA-DRI and DR4 positive patients was amplified by the polymerase chain reaction (PCR). Dot blotting and hybridization with sequence specific oligonucleotide (SSO) probes were performed. The phenotypic frequency of HLA-DRI in RA patients (26,2%) was significantly greater than controls (11,5%) (p<O,05). HLA-DR4 occurred in 24,6% of the patients and in the 18% of controls (p>0,05). The HLA-DRI positive patients did,'not show ditTerences when compared to HLA-DRI negative. Positive DR4 patients had significantly higher tittles of rheumatoid factor, bone erosions and worst functional status (p<0,05). The alleles HLA-DRB 1 *0401 e *0404 were associated with worst functional status, bone erosions and rheumatoid factor. HLA-DRBI *0101 and *0102 were the most frequent aneles, however not associated with clinical and laboratory characteristics. Those with HLA-DRBI *0101, *0401 e *0404 aneles, who presented de shared epitope (QKRAA - QRRAA) at position 70-74, showed erosion more frequently. We can conclude that the HLA-DRBI *0101 and *0102 aneles are associated with susceptibility to RA while *0401 and *0404 with more aggressive disease / Doutorado / Clinica Medica / Doutor em Medicina
216

Modelica Models in a Distributed Environment Using FMI and HLA

Sievert, Nicke January 2016 (has links)
Modelica is a domain independent modeling language allowing for componentbased modeling of complex systems. Functional Mock-up Interface (FMI) defines a standardized interface for complex computer simulations. High Level Architecture (HLA) is an interoperability standard of a general purpose architecture for distributed simulation. This thesis aims to show the possibilities of having Modelica models in a distributed environment by usage of FMI and HLA. An additional objective is to provide a base for a possible generic solution.
217

Lymphocytes B mémoire dans la réponse humorale anti-­HLA en transplantation d'organe / Memory B cells in anti-HLA humoral response in organ transplantation

Snanoudj, Renaud 19 November 2013 (has links)
Les alloanticorps anti-HLA sont dirigés vis-à-vis de différents épitopes des molécules du système HLA. Cette immunisation survient lors d'une transplantation d'organe, de transfusions sanguines ou d'une grossesse. On retrouve aussi ces anticorps, lorsque les techniques de détection sont sensibles, en l'absence de tout évènement immunisant. En transplantation d'organe, rénale en particulier, la présence d’anticorps anti-HLA, du fait des lésions de rejet humoral qu'ils induisent, constitue une des premières causes de perte de fonction des greffons à moyen et long terme. Néanmoins, les cellules lymphocytaires qui sont la source de ces anticorps anti-HLA demeurent mal identifiées.Dans la première partie de ce travail, nous avons étudié, dans une cohorte de patients en attente de transplantation rénale, la distribution des différentes sous-populations lymphocytaires B circulantes par cytométrie de flux en relation avec la nature des évènements immunisants vis-à-vis du système HLA, la présence et la diversité des anticorps anti-HLA. Nous avons étudié en parallèle les concentrations sériques de BAFF ("B cell activating factor belonging to the TNF family"), principal facteur impliqué dans la survie et la différenciation des lymphocytes B matures. Nous avons retrouvé une association entre la présence et la diversité des anticorps anti-HLA, et l'augmentation de la proportion de lymphocytes B naïfs activés Bm2, par rapport aux autres sous-populations lymphocytaires B, et indépendamment de l'existence d'évènements immunisants. Les concentrations sériques de BAFF étaient également associées positivement à la présence et à la diversité des anticorps anti-HLA. Ces données suggèrent que l'augmentation des lymphocytes B naïfs activés et des concentrations sériques de BAFF favorise le développement des anticorps anti-HLA à la suite d'un événement immunisant. A l'instar du mécanisme évoqué en auto-immunité, BAFF pourrait intervenir en présence de l'alloantigène en favorisant la survie de clones B alloréactifs.Dans la deuxième partie de notre travail, nous nous sommes intéressés plus particulièrement à l'implication des lymphocytes B mémoire alloréactifs dans la réponse humorale anti-HLA. Pour détecter les lymphocytes B mémoire circulants, nous avons utilisé un test de stimulation polyclonale permettant leur différenciation en plasmablastes puis nous avons recherché et étudié la spécificité des anticorps anti-HLA produits dans les surnageants de culture. Un premier résultat important a été la possibilité de détecter, chez les patients présentant des anticorps anti-HLA, des lymphocytes B mémoire alloréactifs circulants plusieurs années après un événement immunisant. En deuxième lieu, la présence de ces lymphocytes B mémoire était associée au nombre d'évènements immunisants. En effet, les patients ayant développé, en l'absence d'événement immunisant des anticorps anti-HLA - dont nous montrons par ailleurs le caractère potentiellement pathogène - n'ont pas présenté de lymphocytes B mémoire alloréactifs circulants. Enfin, à l'aide du logiciel HLAMatchmaker, nous avons montré que les anticorps produits par les lymphocytes B mémoire étaient dirigés contre un nombre restreint d'épitopes partagés par plusieurs antigènes HLA, ce qui suggère une oligoclonalité du contingent B mémoire alloréactif. Chez les mêmes patients, les anticorps anti-HLA circulants présentaient une diversité de spécificité plus large, étant dirigés contre de multiples épitopes HLA. Ces résultats suggèrent l'existence d'au moins deux types de réponse humorale vis-à-vis des alloantigènes HLA : l'une aboutissant à la production de lymphocytes B mémoire et de plasmocytes à la suite d'une réaction de centre germinatif T-dépendante, l'autre impliquant seulement des plasmocytes, possiblement issus de réponses extra-folliculaires. Les facteurs orientant vers l’un ou l’autre type de réponse sont encore mal définis mais pourraient impliquer la dose et la voie d'exposition aux alloantigènes. / Anti-HLA antibodies are directed against various epitopes of HLA molecules. They develop during organ transplantations, red cell transfusions or pregnancies. But anti-HLA antibodies are also detected with sensitive assays in the absence of any sensitizing event. In renal transplantation, anti-HLA antibodies, through the development of antibody-mediated rejection, represent the first cause of late allograft loss. Nevertheless, the mechanisms and the exact nature of B cells involved in anti-HLA antibodies synthesis are poorly understood.In a first part, we studied by flow cytometry in patients awaiting kidney transplantation the distribution of the different peripheral B cell subsets in relation with immunizing events, titer and diversity of anti-HLA antibodies. We also studied the serum levels of BAFF ("B cell activating factor belonging to the TNF family"), the main factor involved in survival and differentiation of mature B cells. We found an association between the presence and the diversity of anti-HLA antibodies, and the proportion of activated naive Bm2 B cells, at the expense of other subsets, independently of immunizing events. BAFF serum levels were also positively associated with the presence and the diversity of anti-HLA antibodies. These data suggest that the increase in activated naive B cells and in BAFF levels facilitate the development of anti-HLA antibodies, following an immunizing event. Similarly to what is observed in autoimmunity, BAFF could help to the positive selection of alloreactive B cell clones, in the presence of alloantigen.In a second part, we focused on the role of circulating alloreactive memory B cells in anti-HLA humoral response. To detect those alloreactive memory B cells, we used a polyclonal stimulation assay allowing the differentiation of memory B cells into plasmablasts and we studied the specificity of anti-HLA antibodies recovered from culture supernatant. A first important result was the detection, decades after an imunizing event, of specific alloreactive memory B cells, even in the absence of the antigen. The detection of those circulating alloreactive memory B cells was related to the strength of immunizing events, i.e. the number of different immunizing events in the history of patients. Indeed, patients with anti-HLA antibodies with no history of immunizing event had no circulating alloreactive memory B cells. Eventually, with HLAMatchmaker software, we showed that antibodies produced by memory B cells were directed against a limited number of epitopes shared by HLA antigens, which suggests an oligoclonality of the alloreactive memory B cell population. By comparison, serum antibodies displayed a greater diversity, with multiple epitopic specificities. These results suggest two distinct cellular arms of humoral response towards HLA epitopes: medullar plasma cells, involved in long term HLA antibodies synthesis, and memory B cells waiting for a recall response in the presence of the antigen. The factors involved in the choice of those two cellular fates are poorly understood but may involve dose and route of exposition to the alloantigen.
218

Role of IA-2 antibodies in clinical and preclinical type 1 diabetes

Savola, K. (Kaisa) 29 May 2000 (has links)
Abstract Previous scientific data suggest that beta-cell destruction in type 1 diabetes is mediated by an autoimmune process. This work was aimed at expanding existing knowledge of humoral autoimmunity by analysing antibodies against the intracellular part of the IA-2 protein (IA-2A) in 1200 patients with the disease, 750 siblings and more than 370 non-diabetic controls. IA-2A were present at the time of diagnosis in the overwhelming majority of patients with type 1 diabetes, and were associated with human leucocyte antigen (HLA) DR4 and DQB1*0302, but not with gender. Humoral autoimmunity was more marked in patients diagnosed when younger than 20 years of age than in older ones, but no noticeable association was observed between IA-2A and age under the age of 20 years. IA-2A in combination with antibodies to GAD65 (GADA) identified a higher proportion of patients younger than 15 years of age at the time of diagnosis than did islet cell antibodies (ICA) alone. The levels of IA-2A and the proportions of antibody-positive patients decreased with increasing duration of type 1 diabetes, although more than half of the patients still tested positive for IA-2A after 10 years of clinical disease. IA-2A, GADA, insulin autoantibodies (IAA) and ICA were detected with individual fluctuations in 8-14% of the siblings of children with type 1 diabetes monitored from the time of diagnosis of the proband, and the fluctuations were modified by HLA-defined genetic susceptibility, age of the siblings, family size and total number of detectable autoantibodies. IA-2A positivity detected at the time of diagnosis of the proband increased the risk of future disease in the siblings. The positive predictive value increased with increasing IA-2A levels, although individual risk assessment appeared to be a complex matter. In conclusion, IA-2 appears to be an important autoantigen in type 1 diabetes, since IA-2A is associated with the HLA haplotype that most strongly predisposes subjects to the disease and have the highest positive predictive value for future disease out of the four autoantibodies used for risk assessment purposes.
219

The search for links between immunogenetic factors and recurrent miscarriage

Karhukorpi, J. (Jari) 31 May 2005 (has links)
Abstract Successful pregnancy is characterized by a shift toward Th2 type immune response and suppression of adaptive immune responses to ensure acceptance of the semi-allogenic fetal graft. Also the innate immune system plays a major role during pregnancy. Recurrent miscarriage is defined as three or more consecutive pregnancy losses. About 1% of all women will suffer recurrent miscarriage. The causes of recurrent miscarriage remain unexplained in half (50%) of the cases. Susceptibility to recurrent miscarriage is probably mediated by Th1 type immune response with pronounced expression and secretion of pro-inflammatory cytokines (e.g. TNFα and IFNγ) paralleled with decreased production of anti-inflammatory cytokines (e.g. IL-10). Factors that regulate immune response during pregnancy include hormonal factors (e.g. hCG and progesterone). Immunogenetic factors also contribute to this regulation. Several functionally important polymorphisms in various immunomodulatory genes have been identified during recent years. Some of these polymorphisms may be important in regulating the Th1/Th2 balance during pregnancy. Putative immune dysregulation caused by these polymorphisms has been researched intensively. Conflicting results have been published about associations between several of these polymorphisms and recurrent miscarriage. In this study, HLA-G (exon 2 and 3), IL-10 (-1082A/G), IL-1RA (intron 2 VNTR) and CD14 (-159C/T) polymorphisms were studied in 38 Finnish women with RM. All of these polymorphisms have been associated with altered gene expression. Distribution of HLA-G*I, II, III and IV were 0.577, 0.375, 0 and 0.048 respectively in the studied Finnish population. According to the present classification the G*I allele group mostly consists of the allele 010101, while G*II covers the combination of 010102, 010401 and 0105N, as well as some other rare alleles. There were no associations between recurrent miscarriage and the HLA-G, IL-10 and CD14 polymorphisms. However, in IL-1RA polymorphism, the rare IL1RN*3 allele was increased in women with recurrent miscarriage. It is not known, if this particular allele is associated with differences in IL-1RA or IL-1 production. Although the study population was small, it may be supposed that quantitative differences in the production of single immunomodulatory molecules due to normal genetic variation may not be grossly harmful to the fetal allograft. This indicates the robustness and flexibility of the reproduction system. For survival, it is essential that minor variations are tolerated. Thus, large-scale studies focusing on the effect of a pro-inflammatory genetic profile based on the presence of several pro/anti-inflammatory genetic markers are needed to discover if immunogenetic factors predispose women to recurrent miscarriage.
220

Human Leukocyte Antigen (HLA)class II polymorphisms and Tuberculosis(TB)susceptibility in the Venda population from the Limpopo Province of South Africa.

Lombard, Zane 15 May 2008 (has links)
South Africa is at present encountering one of the worst Tuberculosis (TB) epidemics in the world, accentuating the need for intervention to eradicate TB. Various studies have established that certain population groups are at risk for increased susceptibility to infection with Mycobacterium tuberculosis (M. tuberculosis). This predominantly occurs in populations, like the native African population groups, who were not exposed to TB until the disease arrived in their country with European settlers, colonialists and missionaries. These population groups consequently lack the natural resistance to infection, which other populations developed through years of exposure to the pathogen. Several susceptibility-associated genetic polymorphisms have been proposed to explain differential susceptibility to TB. HLA class II molecules play a pivotal role in the activation of the host immune response against M. tuberculosis. Consequently numerous HLA class II genes have been found to be associated with TB. Among the most commonly observed associations is that of HLA-DR2 with TB, which has been observed in various population groups. Although this association has been observed to transcend ethnic barriers, inter-population variation has also been established regarding HLA-TB associations. In this study, the possible association of HLA class II polymorphisms, specifically of the HLA-DRB1, DQB1, DRB3, DRB4 and DRB5 loci, with TB susceptibility was investigated in the Venda population of South Africa. This was achieved by conducting both a case-control and family-based association study. The results obtained in this study established a unique association between HLA-DRB1*1302, DQ7 and TB susceptibility. A marginally significant association was also observed with DRB1*1301 and DQ6d and possible TB resistance. The above-mentioned results, which were observed in the case-control group, could not be replicated in the family-based study. It was therefore concluded from the results obtained in this study that employing both a case-control and family-based analysis when undertaking an association study is the most beneficial option. / Prof. Liza Bornman

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