Le premier objectif de cette thèse était d’améliorer l’utilisation et la compréhension des outils de mesure de la déformabilité du globule rouge (GR) dans la drépanocytose (Etudes 1 et 2). L’étude 1 a montré l’importance de la standardisation des mesures de déformabilité par ektacytométrie chez les enfants drépanocytaires. Au cours de l’étude 2, les propriétés des GR ont été modifiées et la variation des courbes de déformabilité érythrocytaire « classique » (index d’élongation en fonction de la contrainte de cisaillement en milieu isotonique) a été comparée aux résultats d’osmoscan (mesure de la déformabilité érythrocytaire en gradient osmolaire à contrainte de cisaillement fixe), méthode de référence pour étudier les anomalies de la membrane du GR. Ainsi, les variations de déformabilité érythrocytaire au-delà de 3 Pa sont affectées à la fois par la viscosité interne du GR et par des modifications de la surface cellulaire (rapport surface/volume) alors que les modifications de l’élasticité membranaire affectent la déformabilité érythrocytaire quelles que soient les forces de cisaillements utilisées (faibles, modérées ou hautes). Le deuxième objectif de cette thèse était d’apporter des éléments supplémentaires sur l’implication des facteurs génétiques, des paramètres hémorhéologiques et du niveau de stress oxydant sur la survenue des complications vaso-occlusives chez les patients atteints de syndrome drépanocytaire majeur (Etudes 3 à 6). La mise en commun des résultats d’hémorhéologie obtenus sur 165 patients de notre cohorte lyonnaise et 240 patients de la cohorte guadeloupéenne a permis de montrer que la rhéologie du GR chez les patients drépanocytaires était dépendante de l’âge. Ainsi, la viscosité sanguine augmente avec l’âge pour atteindre un plateau vers 30 ans alors que la déformabilité érythrocytaire diminue avec l’âge (Etude 3). Ces modifications participent vraisemblablement à l’apparition de complications chroniques chez l'adulte drépanocytaire. Les études 4 et 5 ont été réalisées sur la cohorte pédiatrique lyonnaise. Au cours de ces 2 études, nous avons étudié l’influence sur la rhéologie du sang et la survenue de crises vaso-occlusives (CVO) des facteurs génétiques (alpha-thalassémie, déficit en Glucose-6-Phosphate Déshydrogénase (G6PD) et haplotypes S) d’une part (Etude 4) et du niveau de stress oxydant et nitrosatif d’autre part (Etude 5). L’alpha-thalassémie augmente la déformabilité des GR et l’agrégation érythrocytaire. Ces 2 phénomènes pourraient participer à augmenter le risque de CVO. De plus, l’alpha-thalassémie, en diminuant l’hémolyse, diminuerait le niveau de stress oxydant, élément majeur impliqué dans la physiopathologie de la drépanocytose. Enfin, l’étude 6 a montré que la rhéologie sanguine des patients Sbêta+ était quasi-identique à celle des sujets sains AA mais que les patients les plus sévères pourraient avoir un déficit en monoxyde d’azote circulant. En conclusion, mon travail de thèse contribue à une meilleure compréhension de la physiopathologie de la drépanocytose / The first goal of this thesis (Study 1 and 2) was to improve the use and the comprehension of tools for red blood cell (RBC) deformability measurements in sickle cell disease (SCD). The first study showed the importance of standardization of RBC deformability measurements by ektacytometry in SCD children. In the study 2, the RBC proprieties was modified and the variation of « classic » RBC deformability curve (elongation index as a function of the shear stress in isotonic medium) was compared to osmoscan results (elongation index in hyperosmolar gradient and constant shear stress), the gold standard for RBC membrane defect studies. Thus, the modifications of RBC deformability curve above 3 Pa were affected by RBC internal viscosity and cellular surface modification (and thus surface/volume ratio) while membran elasticity modifications affected RBC deformability whatever the shear stress (low, moderate or high). The second goal of this thesis was to study the effects of genetic modifiers, hemorheological parameters and oxidative stress level on vaso-occlusive complications (VOC) in SCD (Study 3 to 6). Hemorheological parameters were measured on 165 patients from Lyon and 240 patients from Gwada and the results showed that blood viscosity increased until the age of 30 and RBC deformability decreased with age (Study 3). This modifications probably play role in the chronic complications of SCD adult patients. The studies 4 and 5 were conducted on SCD children. We studied the effects of genetic modifiers (alpha-thalassemia, glucose-6-phospho-deshydrogenase deficiency and S haplotypes ; study 3) and nitro-oxidative stress level (study 5). Alpha-thalassemia increase RBC deformability and RBC aggregation. This phenomenon could contribute to increase VOC. Moreover, alpha-thalassemia decreased hemolysis and thus oxidative stress, a major component of SCD physiopathology. Then the study 6 showed that Sbeta+ patient hemorheology was quite the same of AA ubjects but the more severe patients could have a defect in circulating nitric oxide. To conclude, my thesis contribute to a better understanding of SCD physiopathology

Made available in DSpace on 2015-03-03T14:03:53Z (GMT). No. of bitstreams: 1 GustavoHMA_DISSERT.pdf: 3193729 bytes, checksum: 228c743c63181279221975bff15e73a2 (MD5) Previous issue date: 2011-02-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Alpha thalassemia, the most common monogenic disorder in the world, is characterized by deletions of one (+-thalassemia) or both alpha genes (0-thalassemia) located on human chromosome 16 (16p13.3). The most common case of +-thalassemia is a deletion of 3.7 kb of DNA (-3.7 deletion). It is most prevalent in African and Middle East regions. In the few studies carried out in Brazilian population -3.7 deletion was the most common deletion, mainly in African descendants. This study was conducted to determine the prevalence of +- thalassemia (deletion 3.7kb) in adult population from Rio Grande do Norte. We obtained blood samples from 713 unrelated individuals of both genders, aged between 18 and 59 years old. All individuals were born in Rio Grande do Norte. The hematological indices were obtained in an automatic cell counter (Micros 60, ABX Diagnostics). The hemoglobin measurement (A2 and Fetal hemoglobin) and the profile confirmation were carried out by high performance liquid chromatography (HPLC) methodology. Genomic DNA was obtained from peripheral blood leukocytes using Illustra Blood GenomicPrep Mini Spin kit and -3.7 deletion was investigated by PCR. Among the 713 individuals studied, 80 (11,2%) presented +- thalassemia: 79 (11,1%) were heterozygous and 1 (0,1%) homozygous for the -3.7 deletion. Considering the ethnic group, negroes showed the greatest prevalence of +-thalassemia (12,5%), followed by mulattoes (12,3%) and caucasian (9,6%). Statistical comparison of hematological parameters between normal individuals and heterozygous to +-thalassemia showed significant differences in RBC (p<0,001), MCV (p<0,001), MCH (p<0,001), Hb A2 (p=0,007) as well as female hemoglobin concentration (p=0,003). This is one of the first studies to research +-thalassemia in general population of Rio Grande do Norte state and these results attest the importance of investigation of this condition to define the etiology of microcytosis and hypochromia. / A talassemia alfa, doen?a monog?nica mais frequente no mundo, ? caracterizada por dele??es envolvendo um dos genes (talassemia a+) ou ambos os genes (talassemia a0) de globina alfa localizados no cluster a no cromossomo 16 (16p13.3). A altera??o presente na maioria dos casos de talassemia a+ ? a dele??o de um fragmento de 3.7 kb de DNA (dele??o -a3.7) com frequ?ncias muito elevadas na regi?o do Mediterr?neo e na ?frica. No Brasil, estudos j? realizados mostram que a dele??o -a3.7 ? a mais frequente, e sendo, encontrada principalmente em indiv?duos de origem africana. O presente estudo teve como objetivo principal determinar a preval?ncia da talassemia alfa+ (dele??o -a3.7) na popula??o adulta do estado do Rio Grande do Norte. Foram obtidas amostras de sangue de 713 indiv?duos (408 do sexo feminino e 307 do sexo masculino) , com idade compreendida entre 18 e 59 anos, n?o aparentados e naturais do estado do Rio Grande do Norte. Os dados hematol?gicos foram obtidos em contador autom?tico de c?lulas (Micros 60, ABX Diagnostics). A confirma??o do perfil hemoglob?nico e a quantifica??o das hemoglobinas A2 e Fetal foram realizadas por cromatografia l?quida de alta performance (HPLC). O DNA foi isolado de leuc?citos do sangue perif?rico utilizando-se o kit ?Illustra blood genomicPrep Mini Spin? (GE Healthcare), e a investiga??o da talassemia alfa (dele??o - 3.7) foi realizada por PCR. Dos 713 indiv?duos investigados, 80 (11,2%) apresentaram talassemia alfa+, sendo 79 (11,1 %) heterozigotos (-a3.7/aa) e 1 (0,1%) homozigoto da dele??o (-a3.7/-a3.7). Considerando a etnia, verificou-se que os indiv?duos negros apresentaram uma maior preval?ncia de talassemia alfa (12,5%), seguido pelos pardos (12,3%) e brancos (9,6%). A compara??o dos ?ndices hematol?gicos entre os indiv?duos com gen?tipo normal e heterozigoto da talassemia alfa+ (dele??o - 3.7) mostrou uma diferen?a estaticamente significante no n?mero de hem?cias (p<0,001), VCM (p<0,001), HCM (p<0,001) e A2 (p=0,007), al?m da dosagem de hemoglobina (p=0,003) para o sexo feminino. O estudo constitui um dos primeiros a investigar a talassemia alfa+ (dele??o -a3.7) na popula??o geral do estado do Rio Grande do Norte e os resultados obtidos evidenciam a import?ncia da investiga??o dessa condi??o a fim de elucidar a etiologia da microcitose e/ou hipocromia

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-11T17:27:27Z No. of bitstreams: 1 danieladeoliveirawerneckrodrigues.pdf: 3809110 bytes, checksum: c650e81b66628763f82026695326df44 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-04-18T12:48:28Z (GMT) No. of bitstreams: 1 danieladeoliveirawerneckrodrigues.pdf: 3809110 bytes, checksum: c650e81b66628763f82026695326df44 (MD5) / Made available in DSpace on 2017-04-18T12:48:28Z (GMT). No. of bitstreams: 1 danieladeoliveirawerneckrodrigues.pdf: 3809110 bytes, checksum: c650e81b66628763f82026695326df44 (MD5) Previous issue date: 2016-05-20 / Introdução: A doença falciforme (DF) é a doença hereditária monogênica mais comum no Brasil.O termo DF inclui Anemia Falciforme (AF) e condições patológicas em que o gene da hemoglobina S está associado a outras hemoglobinopatias hereditárias, tais como SC, S/beta0 e S/beta+ talassemia (S/b), SD Punjab, entre outras. Há descrição de 5 haplótipos do cluster da cadeia globina (βS) ligados à HbS: Asiático, Senegal, Benin, Bantu (CAR) e Camarões. A DF pode ainda coexistir com as α-talassemias (α-Tal). A complicação mais severa na DF é o Acidente Vascular Encefálico (AVE), responsável por 20% da mortalidade. As causas e fatores que aumentariam o risco de AVE não são completamente conhecidos. Várias linhas de evidência sugerem que uma assinatura genética poderia influenciar o desenvolvimento de AVE. Objetivos: Determinar a frequência de DF, investigar a coexistência da α-Tal, identificar os haplótipos e estudar as associações entre estes determinantes genéticos com AVE em crianças triadas pelo Programa Estadual de Triagem Neonatal de Minas Gerais e acompanhadas na Hemominas de Juiz de Fora. Metodologia: Foi realizada uma coorte retrospectiva, na qual foram incluídas as crianças nascidas entre 1998 a 2007, com diagnóstico confirmado de DF. Foram considerados para inclusão no estudo, crianças com Anemia Falciforme (AF), SC, S/b0 e S/b+. As informações clínicas e laboratoriais foram extraídas dos prontuários médicos até 31 de dezembro de 2013 permitindo um acompanhamento de no mínimo cinco anos. O perfil socioeconômico foi obtido através da aplicação do questionário do Instituto Nacional de Estudos e Pesquisas Educacionais Anísio Teixeira. A determinação dos haplótipos e a presença da α-Tal foi realizada por reação em cadeia da polimerase e polimorfismo de tamanho dos fragmentos de restrição. A análise estatística das associações foi feita com aplicação do teste Qui-quadrado considerando-se um nível de significância de 5%, no programa SPSS Statistics® 14.0. O projeto foi aprovado pelo Comitê de Ética e Pesquisa da Fundação Hemominas. Resultados: Entre 1998 e 2007, foram 11 triadas 188.916 crianças nascidas na região da Zona da Mata Mineira e Vertentes, 110 crianças com DF preencheram os critérios de inclusão e constituíram a população deste estudo. Entre as crianças com DF, 60% eram portadoras de AF. A prevalência da coexistência com a α-Tal foi de 30,3% e o haplótipo Bantu (CAR) foi identificado em 89,2%. A incidência de AVE foi significativamente maior nas crianças com AF (27,3% versus 2,3%; p = 0,001) e no sexo masculino (24,1% versus 9,6%; p = 0,044). A presença da α-Tal (p = 0,196), do haplótipo CAR (p = 0,543) e fatores socioeconômicos não foram significantemente associadas à ocorrência de AVE. Conclusões: As crianças com AF tem 12 vezes mais risco de ter AVE do que as que têm outros tipos de DF. A incidência de AVE no sexo masculino foi maior. Coexistência de α-Tal ou haplótipos CAR não apresentaram associação significante com AVE. A heterogeneticidade entre as populações previamente avaliadas e a não reprodutibilidade entre estudos indicam a necessidade de realização de novas pesquisas para verificar o papel desses fatores genéticos em crianças com DF. / Introduction: Sickle cell disease (SCD) is the most common monogenic hereditary disease in Brazil. The term SCD includes sickle cell anaemia and pathological conditions in which the S haemoglobin gene is associated with other hereditary hemoglobinopathies, as SC, S/beta0 and S/beta+ talassemia (S/b), SD Punjab, among others. Five different types of beta globin chain (βS) cluster haplotypes linked to HbS have been described: Asian, Senegalese, Benin, Bantu (CAR) and Cameroon. SCD can also coexist with alpha thalassemia (α-Tal). The most severe complication on SCD is stroke, which is responsible for 20% of mortality. The causes and factors that could increase the risk of stroke are not completely known. Many lines of research suggest that a genetic signature could influence the occurrence of stroke. Objective: Determine the frequency of SCD , identify the haplotypes and study the associations between these genetic determinants and stroke in children screened by the Minas Gerais’ State Program of Neonatal Screening and followed-up in Fundação Hemominas in Juiz de Fora. Methods: A retrospective cohort was established, in which were included children born between 1998 and 2007, with confirmed diagnosis of SCD. Children with sickle cell anaemia, SC, S/b0 and S/b+ were included. The clinical and laboratorial information were extracted from medical records until December 31st, 2013, allowing a follow-up of at least five years. The socioeconomic profile was obtained by applying the Anísio Teixeira National Institute of Studies and Educational Research questionnaire. The haplotype determination and presence of α-Tal was documented through the usage of polymerase chain reaction and restriction fragments length polymorphisms. The statistical analysis of such associations was performed by application of the chi-square test considering a level of significance of 5%, with SPSS Statistics® 14.0 program. The project was approved by Fundação Hemominas’s Reasearch Ethics Committee. Results: Between 1998 and 2007, 188,916 children were screened in Minas Gerais’ Zona da Mata e Vertentes region, 110 children with SCD fulfilled the inclusion 13 criteria and composed the population of this study. Among children with SCD, 60% were carriers of sickle cell anemia. The prevalence of coexistence with α-Tal was 30.3% and the Bantu (CAR) haplotype was identified in 89.2%. The incidence of stroke was significantly higher in children with sickle cell anemia (27.3% versus 2.3%; p = 0.001) and in the male gender (24.1% versus 9.6%; p = 0.044). Presence of α-Tal (p = 0.196), CAR haplotype (p = 0.543) and socioeconomic factors were not significantly associated with the occurrence of stroke. Conclusion: Children with sickle cell anemia have 12 times increased risk of having a stroke than patients with other types of SCD. The incidence of stroke in the male gender was higher. Coexistence with α-Tal and CAR haplotype were not significantly associated with stroke. Heterogeneity between previously assessed populations and non reproducibility among studies indicate the need to conduct further research to determine the role of these genetic factors in children with SCD.

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-06-29T14:15:54Z No. of bitstreams: 1 thaisanettosouzavalentefrossard.pdf: 4978395 bytes, checksum: ac5dc0c8f717447878ea3a336969d945 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-07-03T14:14:30Z (GMT) No. of bitstreams: 1 thaisanettosouzavalentefrossard.pdf: 4978395 bytes, checksum: ac5dc0c8f717447878ea3a336969d945 (MD5) / Made available in DSpace on 2018-07-03T14:14:30Z (GMT). No. of bitstreams: 1 thaisanettosouzavalentefrossard.pdf: 4978395 bytes, checksum: ac5dc0c8f717447878ea3a336969d945 (MD5) Previous issue date: 2018-04-09 / Hipocolesterolemia e hipertrigliceridemia são documentadas na Doença Falciforme (DF) há muitos anos, mas as causas e os efeitos na fisiopatologia ainda precisam ser esclarecidos. Além disto, relatos sobre marcadores genéticos relacionados ao metabolismo lipídico que explicam a variação dos níveis de lipídios e suas associações com os subfenótipos de hemólise e vaso-oclusão e com a variabilidade clínica da DF não foram publicados até o momento. O objetivo geral do estudo foi investigar se havia dislipidemia e se polimorfismos de um único nucleotídeo (SNPs) em genes ligados às variações lipídicas e inflamatórias estariam associados a alterações nas variáveis hematológicas, bioquímicas e clínicas, em crianças e adolescentes com as duas formas mais frequentes da DF, anemia falciforme (HbSS) e hemoglobinopatia SC (HbSC). A população consistiu de 155 indivíduos nascidos entre 2001 e 2010, com média de idade de 12,54 anos, sendo 55,5% do sexo masculino, acompanhados nos Hemocentros Regionais de Governador Valadares e de Uberaba da Fundação Hemominas. Um grupo conrole constituído de 40 crianças sem DF com média de idade de 12,98 anos também foi incluído para comparações com dados lipídicos. Foram realizadas coletas de dados em registros médicos, exames bioquímicos, genotipagens dos SNPs de ANGPTL4, APOA5, ZNF259 e TNFA, pesquisa de alfa-talassemia e avaliação do uso de hidroxiuréia (HU). Verificaram-se associações entre as variáveis investigadas e, destas, com a ocorrência de eventos clínicos da DF. Para estes fins foram aplicados testes qui-quadrado, Mann-Withiney, Teste T de Students, ANOVA, Kruskal-Wallis e realizadas correlações com o teste de Spearman. A significância estatística foi estabelecida em P < 0,05. Dentre os achados, foram encontrados piores índices de marcadores de hemólise e inflamação nos indivíduos HbSS em relação aos HbSC. A hipocolesterolemia (HDL < 40 mg/dL) foi encontrada em 64,52% da população com DF, havendo diferença significativa entre os indivíduos e os controles, sem diferença entre HbSS e HbSC. Indivíduos com DF que possuíam a HDL superior a 40 mg/dL apresentaram maiores níveis de APOA1 e menores de colesterol total e triglicerídios. A hipertrigliceridemia (TG > 100 mg/dL até os 10 anos e > 130 mg/dL acima de 10 anos) presente em apenas 8,51% dos pacientes DF não mostrou diferença significativa entre os grupos HbSS e HbSC e foi associada com níveis elevados da enzima LDH. Nos indivíduos HbSS os baixos níveis de HDL estavam em maior proporção se comparados ao grupo HbSC. O uso de HU no grupo HbSS não interferiu nos níveis de lipídios. A variante rara do gene ANGPTL4 rs116843064 (G>A), no modelo de dominância, foi associada com redução de leucócitos globais e monócitos e aumento de apolipoproteína A1 e colesterol total nos indivíduos com DF. O polimorfismo de ZNF259 rs964184 (c.724C>G) foi associado ao aumento dos marcadores de hemólise/inflamação (leucócitos globais, reticulócitos e bilirrubinas total e direta) e apresentou efeito dose dependente nos níveis de bilirrubina direta. A variante de menor frequência (-308A) de TNFA rs1800629 foi associada com aumento de 73% dos níveis de bilirrubina direta. A co-herança de alfa-talassemia presente nos dois grupos HbSS e HbSC, reduziu VCM e HCM, mas não influenciou os níveis de HbF, reticulócitos, bilirrubina ou o perfil lipídico. Em conclusão, a hipocolesterolemia foi caracterizada por baixos níveis de HDL em ambos os grupos de indivíduos HbSS e HbSC e o uso terapêutico da hidroxiuréia ou a co-existência de alelos de deleção dos genes HBA parecem não influenciar este quadro dislipidêmico. Entre os polimofismos estudados o de ZNF259 rs964184 foi o único associado a níveis de lipídios nos indivíduos com DF. Nosso estudo é o primeiro a mostrar que a variantes de menor frequência de ZNF259 rs964184 e TNFA rs1800629 estão associadas a hiperbilirrubinemia em pacientes com DF. / Hypocholesterolemia and hypertriglyceridemia have been documented in sickle cell disease (SCD) for many years, but the causes and effects on pathophysiology still need to be clarified. In addition, reports on genetic markers related to lipid metabolism that explain the variation of lipid levels and their associations with subtypes of hemolysis and vaso-occlusion and clinical variability of SCD have not been published to date. The overall objective of the study was to investigate whether dyslipidemia and single nucleotide polymorphisms (SNPs) in genes linked to lipid and inflammatory changes would be associated with changes in hematological, biochemical and clinical variables in children and adolescents with the two most frequent forms of SCD, sickle cell anemia (HbSS) and hemoglobinopathy SC (HbSC). The population consisted of 155 individuals born between 2001 and 2010, with a mean age of 12.54 years, being 55.5% male, followed in the Regional Hemocenters of Governador Valadares and Uberaba of the Hemominas Foundation. A conrole group consisting of 40 children without SCD with a mean age of 12.98 years was also included for comparison with lipid data. Data collection on medical records, biochemical tests, genotyping of ANGPTL4, APOA5, ZNF259 and TNFASNPs, alpha-thalassemia screening and assessment of hydroxyurea (HU) use were performed. There were associations between the variables investigated and, of these, with the occurrence of clinical events of the SCD. For these purposes chi-square, Mann-Withiney, Student's T-Test, ANOVA, Kruskal-Wallis and correlations with the Spearman test were applied. Statistical significance was set at P <0.05. Among the findings, we found worse markers of hemolysis and inflammation in HbSS individuals in relation to HbSC. Hypocholesterolemia (HDL <40 mg / dL) was found in 64.52% of the SCD population, with a significant difference between individuals and controls, with no difference between HbSS and HbSC. Individuals with SCD that had HDL greater than 40 mg / dL had higher levels of APOA1 and lower total cholesterol and triglycerides. Hypertriglyceridemia (TG> 100 mg / dL up to 10 years and> 130 mg / dL over 10 years) present in only 8.51% of SCD patients showed no significant difference between the HbSS and HbSC groups and was associated with high levels of the LDH enzyme. In the HbSS subjects the low HDL levels were in a higher proportion when compared to the HbSC group. The use of HU in the HbSS group did not interfere with lipid levels. The rare variant of the ANGPTL4 gene rs116843064 (G> A) in the dominance model was associated with reduction of global leukocytes and monocytes and increase of apolipoprotein A1 and total cholesterol in subjects with DF. The polymorphism of ZNF259 rs964184 (c.724C> G) was associated with increased markers of hemolysis/ inflammation (total leukocytes, reticulocytes and total and direct bilirubin) and had a dose-dependent effect on direct bilirubin levels. The lower frequency variant (-308A) of TNFA rs1800629 was associated with a 73% increase in direct bilirubin levels. Alpha-thalassemia co-inheritance in both HbSS and HbSC groups reduced MCV andMCH, but did not influence HbF, reticulocyte, bilirubin or lipid profile levels.In conclusion, hypocholesterolemia was characterized by low levels of HDL in both groups of HbSS and HbSC and the therapeutic use of hydroxyurea or the coexistence of deletion alleles of HBA genes does not appear to influence this dyslipidemic condition. Among the polymorphisms studied, that of ZNF259 rs964184 was the only one associated with lipid levels in SCD. Our study is the first to show that the lower frequency variants of ZNF259 rs964184 and TNFA rs1800629 are associated with hyperbilirubinemia in SCD.

Orientador: Maria de Fátima Sonati / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-25T22:02:31Z (GMT). No. of bitstreams: 1 Fernandes_ThalesAllyrioAraujodeMedeiros_D.pdf: 2937928 bytes, checksum: 301442af6cf4af176a07dec075589b81 (MD5) Previous issue date: 2014 / Resumo: As doenças falciformes apresentam uma heterogeneidade fenotípica substancial e vários fatores, tanto genéticos quanto ambientais, contribuem para esta variabilidade. A co-herança com a talassemia ? e os haplótipos ?S são considerados importantes moduladores genéticos da doença, mas outros fatores hereditários podem também influenciar os perfis clínicos e laboratoriais dos pacientes. Estudos têm sugerido que os genótipos da haptoglobina (Hp) poderiam estar entre esses fatores. Assim, o presente estudo objetivou avaliar o efeito da presença da talassemia ?, dos diferentes haplótipos ?S e dos genótipos da haptoglobina na evolução clínica e nas características laboratoriais de pacientes com doença falciforme provenientes do estado do Rio Grande do Norte (RN). Foram analisados 155 indivíduos não aparentados (82 homens e 73 mulheres), com idades variando de 7 meses a 48 anos (mediana de 12 anos), provenientes de diversos municípios do RN e atendidos nos centros de referência de tratamento de doenças hematológicas para acompanhamento ambulatorial. Todos os pacientes, ou seus responsáveis, foram informados a respeito dos objetivos e procedimentos da pesquisa, e responderam a um questionário padronizado. Ao final, coletaram-se alíquotas de sangue periférico para a realização das análises hematológicas, bioquímicas e moleculares. Posteriormente, foram examinados os prontuários médicos arquivados nestes centros, de onde foram obtidas as informações relativas à evolução clínica (número de internações e transfusões nos últimos 12 meses, necessidade de estabelecimento de terapia transfusional crônica, desenvolvimento de infecções bacterianas graves, síndrome torácica aguda, sequestro esplênico, alterações cerebrovasculares, priapismo, úlcera de perna, necrose óssea, problemas cardiovasculares, renais e oftalmológicos, colelitíase, déficit ponderal e retardo no crescimento). Predominaram os indivíduos com idades inferiores a 12 anos, que se autodeclararam mulatos, que moravam em pequenas cidades relativamente distantes dos centros de referência e que possuíam baixo nível educacional e socioeconômico. Os pacientes com idades inferiores a 10 anos foram diagnosticados com a doença mais precocemente. Quase 50% dos indivíduos analisados faziam uso de hidroxiuréia, 91,4% relatou ter recebido vacinação pneumocócica/meningocócica e 76,1% já tinha feito uso profilático de penicilina alguma vez na vida. A co-herança com a talassemia alfa foi encontrada em 11,6% dos pacientes e não mostrou associação significativa com nenhuma das complicações clínicas avaliadas. No entanto, os pacientes ?-talassêmicos apresentaram maiores níveis de hemácias e hematócrito, e menores valores de hemoglobina corpuscular média (HCM). Os haplótipos ?S mais frequentes foram o CAR (77,5%), Benin (11,9%) e Camarões (5,5%). A homozigoze do haplótipo CAR esteve associada à maior incidência de retardo no crescimento, enquanto as demais combinações de haplótipos apresentaram valores significativamente maiores de hemoglobina e hemácias. A distribuição dos genótipos da haptoglobina estava em equilíbrio de Hardy-Weinberg em todos os grupos considerados e o tipo predominante foi o Hp2-1 (47,7%). As frequências dos alelos HP*1 (0,503) e HP*2 (0,497) foram muito semelhantes. A herança do alelo HP*2 se correlacionou significativamente com a necessidade de implementação da terapia transfusional crônica ao longo da vida e a níveis mais elevados de ferritina. Já os homozigotos do alelo HP*1 (18 pacientes) apresentaram níveis mais elevados de LDH e AST, que deixaram de ser significativos quando se incluiu na análise os indivíduos que faziam uso da hidroxiuréia (10 pacientes). Nossos resultados sugerem que os fatores genéticos aqui avaliados influenciaram em algum grau a evolução clínica e/ou os perfis laboratoriais dos pacientes desta amostra populacional. A ausência de associação significativa com as demais complicações aqui investigadas reflete a natureza multifatorial da doença e a necessidade de ampliação do tamanho amostral em estudo / Abstract: Sickle cell disease presents a significant phenotypic heterogeneity, and both genetic and acquired factors contribute to this variability. Co-inheritance of alpha-thalassemia and ?S haplotypes are the major genetic modifiers of the disease, but others inherited features can influence the clinical and laboratorial profile of the patients. Reports have suggested that haptoglobin genotypes could be one. Therefore, this study aimed to evaluate the effect of alpha thalassemia, ?S haplotypes and genotypes of haptoglobin in the clinical outcome and laboratorial characteristics of patients with sickle cell disease of Rio Grande do Norte State (RN). We analyzed 155 non-related individuals (82 men and 73 women) with sickle cell disease from various municipalities of RN, ages ranging from 7 months to 48 years (median age 12 years), who went to referral centers for outpatient visits. All the patients, or their caregivers, were informed about the research procedures and objectives, and answered a standardized questionnaire. After this, we collected blood samples for hematological, biochemical, and molecular analyses. Additionally, clinical data (number of blood transfusions and hospital admission in the last 12 months, need for chronic transfusion therapy, development of severe bacterial infections, acute chest syndrome, splenic sequestration, cerebrovascular disease, priapism, leg ulcers, osteonecrosis, cardiovascular, renal, and ophthalmologic problems, gallstones, weight deficit and stunted growth) were obtained from the patients¿ medical records archived in these referral centers. The patients were predominantly younger than 12 years old, self-declared as mulatto, lived in small cities relatively distant from the referral center, and had a low education and socio-economic level. Individuals who were 10 or younger were diagnosed at an earlier age. Almost 50% of the patients were taking hydroxyurea, 91.4% reported having received pneumococcal/meningococcal vaccination and 76.1% have ever done prophylactic use of penicillin. The co-inheritance of alpha thalassemia was found in 11.6% of patients and presented no significant association with any clinical complication of sickle cell disease. However, patients with this genetic feature had higher red blood cell (RBC) counts and packet cell volume (PCV), and lower values of mean corpuscular hemoglobin (MCH). The ?S haplotypes more frequent were CAR (77.5%), Benin (11.9%) and Cameroon (5.5%). The homozygous CAR/CAR haplotype was associated with higher incidence of stunted growth, while the other haplotype presented higher hemoglobin and RBC. The distribution of haptoglobin genotype were in Hardy-Weinberg equilibrium in all the groups, and the predominant type was Hp2-1 (47.7%). The frequencies of HP*1 (0.503) and HP*2 (0.497) alleles were similar. The inheritance of HP*2 allele was significantly correlated to the requirement of chronic transfusion therapy and higher levels of ferritin. On the other hand, the Hp1-1 patients (18 individuals) had higher levels of LDH and AST, that were not significant when we included in the analysis the individuals who were using hydroxyurea (10 individuals). Our results suggest that the genetic characteristics evaluated in this study influenced in a certain extent the clinical outcome and/or laboratorial profile of patients with sickle cell disease from RN. The absence of significant association with the others clinical complications reflect the multifactorial nature of these events and the need to increase the analyzed sample size / Doutorado / Ciencias Biomedicas / Doutor em Ciências Médicas

Le premier objectif de cette thèse était de déterminer les effets isolés et combinés de l'alpha thalassémie, des polymorphismes inducteurs (QTLs) de l'HbF et du génotype G6PD dans un contexte d'évolution naturelle de la drépanocytose (Etudes 1 et 2). L'étude 1 a permis d'évaluer pour la première fois les fréquences alléliques de ces gènes modificateurs chez 301 enfants sénégalais SS. Contrairement aux autres populations africaines, le Variant Betica de la G6PD était majoritaire par rapport au variant A(-). De plus, 12% de notre cohorte avait un déficit en G6PD combiné à une absence d'alpha-thalassémie. Ces patients-là seront à privilégier pour la réalisation d'un Doppler transcrânien. Les résultats obtenus dans l'étude 2 nous ont permis de conclure que l'alpha-thalassémie et les QTLs de l'HbF sont interdépendants et ne doivent pas être étudiés séparément pour une prédiction clinique précise. En effet, une combinaison d'alpha-thalassémie avec au moins 2 QTLs de l'HbF est nécessaire pour retarder de manière significative la première complication de la maladie. Cependant, une alpha-thalassémie homozygote, même associée à 3 à 6 QTLs de l'HbF, augmente la fréquence des CVO pendant l'enfance. Par conséquent, une alpha-thalassémie hétérozygote avec au moins deux QTL HbF constituerait le génotype le plus favorable relativement à la survenue des CVO. Le deuxième objectif de cette thèse était d'étudier les interrelations entre le stress oxydant (phénotype et génotype) et la sévérité clinique de la maladie (Etudes 3 à 4). La drépanocytose est caractérisée par un stress oxydatif élevé pouvant expliquer une partie des manifestations cliniques. Nos résultats ont montré que l'alpha-thalassémie homozygote semble diminuer le stress oxydatif, ce qui contribuerait à son effet protecteur sur certaines complications du sous-phénotype hémolytique. En outre, les patients qui ont le moins d'hospitalisations et de CVO semblent présenter une meilleure défense antioxydante (activités catalase et GPx augmentées). Dans l'étude 4 nous avons étudié 4 SNPs de gènes du stress oxydant (rs4880 du gène SOD2, rs207454 du gène XO, rs233322 du gène MPO et rs35652124 du gène NFE2L2). Le SNP rs4880 aurait un effet favorable au niveau biologique (réticulocytose moindre, activité GPx augmentée) mais sans traduction clinique associée. Il en est de même pour rs233322 qui serait associé à une hémolyse et à un stress oxydatif (AOPP) plus importants. En revanche, une tendance à un effet protecteur de rs207454 vis-à-vis de certaines complications (hospitalisations, ostéonécrose, sepsis, STA) a été observée. Notre travail contribue à la compréhension de l'impact des gènes modificateurs dans la drépanocytose. Il pourrait donc permettre, via une sélection positive des patients à risque, d'améliorer la prise en charge de la maladie dans les pays où les traitements de fond (hydroxyurée, doppler transcrânien, échanges transfusionnels) ne peuvent être proposés à tous / The primary objective of this thesis was to determine the isolated and combined effects of alpha-thalassemia, inductors polymorphisms (QTLs) of HbF and genotype G6PD in a context of natural progression of sickle cell disease (Studies 1 and 2). Study 1 was undertaken to evaluate for the first time the allelic frequencies of these modifiers genes in 301 Senegalese SS children. Unlike other African populations, the G6PD Betica Variant was predominant over the A (-) variant. In addition, 12% of our cohort had G6PD deficiency combined with no alpha-thalassemia. These patients will be favoured for the realization of a transcranial doppler. The results obtained in Study 2 allowed us to conclude that alpha thalassemia and QTLs of HbF are interdependent and should not be studied separately for accurate clinical prediction. Indeed, a combination of alpha thalassemia with at least 2 QTLs of HbF is required to significantly delay the first complication of the disease. However, a homozygous alpha thalassemia, even associated with 3 to 6 QTLs of HbF, increases the frequency of CVOs during childhood. Therefore, a heterozygous alpha-thalassemia with at least two QTL HbFs would be the most favourable genotype for the occurrence of CVOs. The second objective of this thesis was to study the interrelationships between oxidative stress and the clinical severity of the disease (Studies 3 to 4). Sickle cell disease is characterized by high oxidative stress that may explain some of the clinical manifestations. Our results showed that homozygous alpha-thalassemia appears to reduce oxidative stress, which would contribute to its protective effect on certain complications of the hemolytic sub-phenotype. In addition, patients with the least hospitalization and CVO appear to have better antioxidant defense (catalase and GPx activities increased). In Study 4 we studied 4 SNPs of oxidative stress genes (rs4880 of the SOD2 gene, rs207454 of the XO gene, rs233322 of the MPO gene and rs35652124 of the NFE2L2 gene). The rs4880 SNP would have a favourable effect on the biological level (less reticulocytosis, increased GPx activity) but without associated clinical translation. The same is true for rs233322, which is associated with greater haemolysis and oxidative stress (AOPP). On the other hand, a tendency to a protective effect of rs207454 for some complications (hospitalizations, osteonecrosis, sepsis, STA) was observed. Our work contributes to the understanding of the impact of modifiers genes in sickle cell disease. It could therefore, through a positive selection of at-risk patients, improve the management of the disease in countries where the basic treatments (hydroxyurea, transcranial doppler, blood transfusion) cannot be offered to all

Orientadores: Maria de Fatima Sonati, Maricilda Palandi de Mello / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-10T14:17:59Z (GMT). No. of bitstreams: 1 Wenning_MarciaReginadeSouzaCossa_D.pdf: 2460425 bytes, checksum: bd59f41846de3b0439b17450b12154a1 (MD5) Previous issue date: 2007 / Resumo: A Doença da Hb H resulta da remoção ou inativação de três dos quatro genes da cadeia a da hemoglobina normalmente presentes no genoma diplóide e é caracterizada por anemia hemolítica crônica de intensidade moderada a grave. Os pacientes apresentam microcitose, hipocromia e poiquilocitose, com cerca de 25 a 30% de Hb Bart¿s (?4) ao nascimento e 5-30% de Hb H (ß4) na vida adulta. Embora a base molecular da doença tenha influência nos níveis de Hb H produzidos, uma heterogeneidade em relação a esse aspecto tem sido observada mesmo em pacientes com genótipos a idênticos, sugerindo que outros fatores contribuem para esta diversidade além dos determinantes talassêmicos. No presente trabalho, procuramos identificar transcritos diferencialmente expressos nos reticulócitos de dois pacientes com Doença da Hb H, irmãos, de origem étnica mista (chinesa e africana), um do sexo masculino, 21 anos de idade, com 18% de Hb H (MKS), e outro do sexo feminino, 19 anos, com 5% desta Hb (FKS), ambos com genótipo -a3.7/--SEA. O método envolveu a técnica de Differential Display Reverse Transcription-Polymerase Chain Reaction (DDRT-PCR) e a realização de Hibridização Subtrativa Supressiva (SSH). A validação dos achados foi feita pela Reação em Cadeia da Polimerase quantitativa em Tempo Real (qRT-PCR). Quatro perfis diferenciais de expressão foram selecionados, todos mais representados no paciente com maior nível de Hb H. Dois foram detectados por ambas as abordagens metodológicas: um transcrito altamente homólogo à parte do gene da PIP5KIIA (fosfatidilinositol 4-fosfato-5 quinase tipo II a) e outro ao gene da cadeia ß da hemoglobina humana. Os outros dois transcritos, selecionados apenas pela SSH, apresentararam similaridade ao gene FAM46C (Family with sequence similarity 46, member C), que corresponde a uma proteína hipotética de função indeterminada, e ao gene EIF4E-BP1 (eukariotic translation initiation factor 4E ¿ binding protein 1), que codifica uma proteína regulatória da tradução com capacidade de inibição do fator eIF4E (eukariotic translation initiation factor 4E). Na tentativa de identificar os mecanismos responsáveis pelo aumento dos transcritos da PIP5KIIA e da globina ß nos reticulócitos de MKSalguns outros genes, relacionados às vias de atuação ou ao processo de transcrição dos primeiros, tiveram sua expressão também avaliada pela qRT-PCR. Os resultados obtidos, embora não conclusivos, sugeriram que a diferença nos níveis de Hb H apresentada pelos pacientes aqui estudados está correlacionada com a taxa de síntese de cadeias ß, e que a enzima PIP5KIIA, provavelmente via sinalização celular pelo fosfatidilinositol, de alguma maneira participa de sua regulação. O significado destes achados e o papel dos transcritos dos genes FAM46C e EIF4E-BP1 devem ser futuramente investigados para uma melhor compreensão dos mecanismos de regulação da expressão dos genes da globina ß em pacientes com talassemia a / Abstract: Hb H disease results from the inactivation of three of the four a-globin genes normally present on diploid genome and it is characterized by a moderate to severe chronic hemolytic anemia. Patients usually present microcytosis, hypochromia and poikilocytosis, with 25 to 30% of Hb Bart¿s (?4) at birth and 5 to 30% of Hb H (ß4) in adult life. Although the molecular base of this disease influences the Hb H levels produced, some heterogeneity has been observed in relation to this aspect, even in patients with identical a genotypes, thus suggesting that other factors contribute to this diversity besides a-thalassemic determinants. The aim of the present study was to identify differentially expressed transcripts in the reticulocytes from two patients with Hb H disease, siblings, from Chinese and African origins, a 21-year- old male (MKS) with 18% of Hb H and a 19-year-old female (FKS) with 5% of Hb H, both with genotype -a3.7/--SEA. The methodology involved two techniques: the Differential Display Reverse Transcription-Polymerase Chain Reaction (DDRT-PCR) and the Suppression Subtractive Hybridization (SSH). Quantitative real time PCR (qRT-PCR) experiments were used to confirm some results. Four differentially expressed profiles were obtained, all of them better represented in the subject with the highest Hb H level. Two transcripts were detected by both methodological approaches, one being highly similar to PIP5KIIA gene (Phosphatidylinositol ¿ 4 phosphate 5-kinase, type II a) and the other one similar to human ß-globin gene. Two others transcripts were selected only by SSH and they showed to be to FAM 46C (Family with sequence similarity 46, member C) and EIF4E-BP1 (eukariotic translation initiation factor 4E-binding protein 1) gene homologues. In order to identify the mechanisms that are responsible for the transcripts PIP5KIIA and ß- globin increase in the reticulocytes from MKS patient, some other genes related to the transcriptional process also had its expression evaluated by qRT-PCR. Although not conclusive, our results suggest that the difference between the Hb H levels, showed by the subjects here studied, is correlated with ß-globin synthesis rate and that PIP5KIIA may participate of its regulation, probably by cell signalizing through Phosphatidylinositol. Studies, particularly involving a higher number of patients, and experiments aimed at elucidating the PIP5KIIA function in erythroid cells, should help to understand this process. The initiation factor -4E binding protein (EIF4E-BP1) and its capacity to bind to eIF4E, acts as negative regulator of cell growth. Its overexpression was detected in the patient with the highest HbH level. The significance of these findings and the role of the FAM46C and EIF4E-BP1 gene transcripts should be further investigated so that the regulating of the ß-globin gene expression in a-thalassemic patients can be better understood / Doutorado / Medicina Experimental / Doutor em Fisiopatologia Medica

Made available in DSpace on 2014-07-29T15:10:32Z (GMT). No. of bitstreams: 1 tese final Karlla.pdf: 1794329 bytes, checksum: 2a2d0436bd4d9a7eeebe61077580e8f9 (MD5) Previous issue date: 2009-03-27 / Alpha thalassemia is a syndrome resulting from disturbances in the synthesis of alpha globin chain that forms the tetramer of the hemoglobin molecule. Alpha thalassemia is classified into four types according to the number of alpha genes affected: silent carrier (-&#945;/&#945;&#945;), alpha thalassemia trait (--/&#945;&#945; or -&#945;/-&#945;) Hemoglobin H disease (-- /-&#945;), and fetalis hydrops (--/--). The decrease in synthesis of alpha globin causes inadequate production of hemoglobin resulting in hypochromic and microcytic anaemia. Also it causes accumulation of beta chains, inside the erythrocytes, resulting in formation of beta chain tetramer of hemoglobin called Hb H. Clinically the individual with thalassemia can be asymptomatic or present severe anemia. Asymptomatic forms of thalassemia, silent carrier and alpha thalassemia trait, are more difficult to diagnose because of the inclusions bodies of Hb H are not always present. In these situations it is necessary to research the molecular characterization of the genotype and confirming the presence of alpha thalassemia. This is mainly because the diagnosis by conventional methods, although important, is limited and imprecise. This study evaluated some of the traditional laboratory methods in the detection of alpha thalassemia and associated molecular characterization of the more prevalent deletion forms &#945;3,7 and &#945;4,2. For confirmation and characterization of alpha thalassemia, new oligonucleotides were designed. By conventional PCR technique, using 3.7F/KGB01 primers it was possible to detect the deletion &#945;3,7, differentiating the normal genotype (&#945;&#945;/&#945;&#945;), the heterozygote (-&#945;3,7/&#945;&#945;), and homozygous (-- &#945;3,7/- &#945;3,7). Although it was designed to detect the deletion &#945;3,7, this primers also identified the deletion &#945;4,2 when in homozigose (-&#945;4,2/- &#945;4,2). The primers KGB04/KGB05 detected the deletion &#945;4,2, but without differentiating between the heterozygous and homozygous genotype. The most prevalent deletion founded was the &#945;4,2 (20.0%) which represents 9.2% in the homozygous form (- &#945;4,2/-&#945;4,2). The deletion &#945;3,7 in the heterozygous form was detected in 12.3% of patients. The data demonstrate that the importance of molecular detection for alpha thalassemia is not limited only to the definition of the genotype, but also confirmation of the presence in patients with abnormal erythrogram values, with regular erythrogram values, with values closed to the boundary values and in neonates. / A talassemia alfa é uma síndrome resultante de distúrbios na síntese da cadeia da globina alfa que formam o tetrâmero da molécula da hemoglobina. A talassemia alfa é classificada em quatro tipos de acordo com o número de genes alfa afetado: portador silencioso (-&#945;/&#945;&#945;); traço alfa talassêmico (--/&#945;&#945; ou - &#945;/-&#945;); doença de hemoglobina H (--/-&#945;) e hidropsia fetal (--/--). A diminuição na síntese de globina alfa causa a produção inadequada de hemoglobina que resulta em anemia microcítica e hipocrômica. Causa também o acúmulo de cadeias do tipo beta, no interior do eritrócito, pela falta de balanceamento com a síntese da globina alfa afetada. O resultado deste desbalanceamento é a formação de tetrâmeros de cadeias beta denominados Hb H. Clinicamente o indivíduo portador de talassemia alfa pode ser assintomático ou apresentar anemia severa. As formas assintomáticas da talassemia alfa, o portador silencioso e o traço alfa talassêmico, são mais difíceis de diagnosticar, pois os corpúsculos de Hb H nem sempre estão presentes. Para estas situações faz-se necessária a investigação molecular visando a caracterização do genótipo e a confirmação da presença da talassemia alfa. Este fato se deve principalmente porque o diagnóstico através de métodos clássicos não moleculares, apesar de importantes, é limitado e impreciso. O presente trabalho avaliou alguns dos métodos laboratoriais clássicos na detecção de talassemia alfa e associou a caracterização molecular das formas delecionais mais prevalentes &#945;3,7 e &#945;4,2. Para a confirmação e caracterização da talassemia alfa, foram desenhados novos oligonucleotídeos. Através da técnica convencional da PCR, utilizando o par de oligonucleotídeos 3.7F/KGB01 foi possível detectar a deleção &#945;3,7, diferenciando o genótipo normal (&#945;&#945;/&#945;&#945;), do heterozigoto ( &#945;3,7/&#945;&#945;) e do homozigoto ( &#945;3,7/ &#945;3,7). Apesar de ter sido desenhado para detectar a deleção &#945;3,7, este par também permitiu detectar a deleção &#945;4,2 quando em homozigose ( &#945;4,2/ &#945;4,2). Utilizando o par KGB04/KGB05 foi possível detectar a deleção &#945;4,2, porém sem diferenciar entre o genótipo heterozigoto e homozigoto. A deleção mais prevalente encontrada foi a &#945;4,2 (20,0%) sendo que destas podemos afirmar que 9,2% estão na forma homozigótica ( &#945;4,2/ &#945;4,2). A deleção do tipo &#945;3,7 na forma heterozigótica foi detectada em 12,3% dos pacientes. Os dados obtidos revelam que a importância da detecção molecular para talassemia alfa não se restringe apenas na definição do genótipo, mas também na detecção deste tipo de talassemia em pacientes que apresentam: quadros hematológicos alterados, quadros hematológicos normais, mas com valores próximos aos valores limítrofes e em neonatos.