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Cardiomyopathies are a group of inherited heart muscle disorders. Expressivity is variable and while sometimes mild, complications can result in sudden cardiac death (SCD) at any age, heart failure and stroke. In around a third of patients a monogenic cause is identifiable, and development of genetic therapies that aim to correct the underlying genetic defect is underway. Here we describe results of a survey designed to understand preliminary views of the patient community about genetic therapies in the context of disease burden. The internet survey was publicized with a bespoke information video via patient support groups in the UK and USA; 634 people responded of whom 96% had a personal and/or family history of cardiomyopathy. Findings show that concern about cardiomyopathy-related issues with a future dimension, such as disease progression, is significantly greater than concern about current issues. A total of 93.6% thought that genetic therapies should be developed for cardiomyopathy. A majority would consider participation in a genetic therapy trial in six scenarios varying by age and clinical situation significantly more in the scenario of an adult with symptomatic disease and evident progression than an asymptomatic adult with SCD risk, or a child. In all scenarios, a majority said that the chance genetic therapy would stop or slow progression, and risk of serious adverse and unintended effects, were important considerations. Qualitative analysis of free-text responses found that concern was often informed by family experience. Patient consideration of genetic therapy is likely to require individualized assessment of the benefits and risks.
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The clinical severity of sickle cell disease (SCD) is strongly influenced by the level of fetal haemoglobin (HbF) persistent in each patient. Three major HbF loci (BCL11A, HBS1L-MYB, and Xmn1-HBG2) have been reported, but a considerable hidden heritability remains. We conducted a genome-wide association study for HbF levels in 1006 Nigerian patients with SCD (HbSS/HbSß0), followed by a replication and meta-analysis exercise in four independent SCD cohorts (3,582 patients). To dissect association signals at the major loci, we performed stepwise conditional and haplotype association analyses and included public functional annotation datasets. Association signals were detected for BCL11A (lead SNP rs6706648, ß = -0.39, P = 4.96 × 10-34) and HBS1L-MYB (lead SNP rs61028892, ß = 0.73, P = 1.18 × 10-9), whereas the variant allele for Xmn1-HBG2 was found to be very rare. In addition, we detected three putative new trait-associated regions. Genetically, dissecting the two major loci BCL11A and HBS1L-MYB, we defined trait-increasing haplotypes (P < 0.0001) containing so far unidentified causal variants. At BCL11A, in addition to a haplotype harbouring the putative functional variant rs1427407-'T', we identified a second haplotype, tagged by the rs7565301-'A' allele, where a yet-to-be-discovered causal DNA variant may reside. Similarly, at HBS1L-MYB, one HbF-increasing haplotype contains the likely functional small indel rs66650371, and a second tagged by rs61028892-'C' is likely to harbour a presently unknown functional allele. Together, variants at BCL11A and HBS1L-MYB SNPs explained 24.1% of the trait variance. Our findings provide a path for further investigation of the causes of variable fetal haemoglobin persistence in sickle cell disease.
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Anemia Falciforme , Proteínas de Ligação ao GTP , Estudo de Associação Genômica Ampla , Haplótipos , Feminino , Humanos , Masculino , Alelos , Anemia Falciforme/genética , Anemia Falciforme/sangue , Predisposição Genética para Doença , Nigéria , Proteínas Nucleares/genética , Polimorfismo de Nucleotídeo Único/genética , Proteínas Repressoras/genéticaRESUMO
BACKGROUND: A large proportion of genetic risk remains unexplained for structural heart disease involving the interventricular septum (IVS) including hypertrophic cardiomyopathy and ventricular septal defects. This study sought to develop a reproducible proxy of IVS structure from standard medical imaging, discover novel genetic determinants of IVS structure, and relate these loci to diseases of the IVS, hypertrophic cardiomyopathy, and ventricular septal defect. METHODS: We estimated the cross-sectional area of the IVS from the 4-chamber view of cardiac magnetic resonance imaging in 32 219 individuals from the UK Biobank which was used as the basis of genome wide association studies and Mendelian randomization. RESULTS: Measures of IVS cross-sectional area at diastole were a strong proxy for the 3-dimensional volume of the IVS (Pearson r=0.814, P=0.004), and correlated with anthropometric measures, blood pressure, and diagnostic codes related to cardiovascular physiology. Seven loci with clear genomic consequence and relevance to cardiovascular biology were uncovered by genome wide association studies, most notably a single nucleotide polymorphism in an intron of CDKN1A (rs2376620; ß, 7.7 mm2 [95% CI, 5.8-11.0]; P=6.0×10-10), and a common inversion incorporating KANSL1 predicted to disrupt local chromatin structure (ß, 8.4 mm2 [95% CI, 6.3-10.9]; P=4.2×10-14). Mendelian randomization suggested that inheritance of larger IVS cross-sectional area at diastole was strongly associated with hypertrophic cardiomyopathy risk (pIVW=4.6×10-10) while inheritance of smaller IVS cross-sectional area at diastole was associated with risk for ventricular septal defect (pIVW=0.007). CONCLUSIONS: Automated estimates of cross-sectional area of the IVS supports discovery of novel loci related to cardiac development and Mendelian disease. Inheritance of genetic liability for either small or large IVS, appears to confer risk for ventricular septal defect or hypertrophic cardiomyopathy, respectively. These data suggest that a proportion of risk for structural and congenital heart disease can be localized to the common genetic determinants of size and shape of cardiovascular anatomy.
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Cardiomiopatia Hipertrófica , Comunicação Interventricular , Humanos , Estudo de Associação Genômica Ampla , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Cardiomiopatia Hipertrófica/genética , Cardiomiopatia Hipertrófica/complicações , Comunicação Interventricular/diagnóstico por imagem , Comunicação Interventricular/genética , Comunicação Interventricular/complicações , Coração , Imageamento por Ressonância MagnéticaRESUMO
The 3-dimensional spatial and 2-dimensional frontal QRS-T angles are measures derived from the vectorcardiogram. They are independent risk predictors for arrhythmia, but the underlying biology is unknown. Using multi-ancestry genome-wide association studies we identify 61 (58 previously unreported) loci for the spatial QRS-T angle (N = 118,780) and 11 for the frontal QRS-T angle (N = 159,715). Seven out of the 61 spatial QRS-T angle loci have not been reported for other electrocardiographic measures. Enrichments are observed in pathways related to cardiac and vascular development, muscle contraction, and hypertrophy. Pairwise genome-wide association studies with classical ECG traits identify shared genetic influences with PR interval and QRS duration. Phenome-wide scanning indicate associations with atrial fibrillation, atrioventricular block and arterial embolism and genetically determined QRS-T angle measures are associated with fascicular and bundle branch block (and also atrioventricular block for the frontal QRS-T angle). We identify potential biology involved in the QRS-T angle and their genetic relationships with cardiovascular traits and diseases, may inform future research and risk prediction.
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Bloqueio Atrioventricular , Doenças Cardiovasculares , Humanos , Doenças Cardiovasculares/genética , Estudo de Associação Genômica Ampla , Fatores de Risco , Arritmias Cardíacas/genética , Eletrocardiografia/métodos , BiomarcadoresRESUMO
Hypertrophic cardiomyopathy (HCM) is an important cause of morbidity and mortality with both monogenic and polygenic components. We here report results from the largest HCM genome-wide association study (GWAS) and multi-trait analysis (MTAG) including 5,900 HCM cases, 68,359 controls, and 36,083 UK Biobank (UKB) participants with cardiac magnetic resonance (CMR) imaging. We identified a total of 70 loci (50 novel) associated with HCM, and 62 loci (32 novel) associated with relevant left ventricular (LV) structural or functional traits. Amongst the common variant HCM loci, we identify a novel HCM disease gene, SVIL, which encodes the actin-binding protein supervillin, showing that rare truncating SVIL variants cause HCM. Mendelian randomization analyses support a causal role of increased LV contractility in both obstructive and non-obstructive forms of HCM, suggesting common disease mechanisms and anticipating shared response to therapy. Taken together, the findings significantly increase our understanding of the genetic basis and molecular mechanisms of HCM, with potential implications for disease management.
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BACKGROUND: Left ventricular maximum wall thickness (LVMWT) is an important biomarker of left ventricular hypertrophy and provides diagnostic and prognostic information in hypertrophic cardiomyopathy (HCM). Limited information is available on the genetic determinants of LVMWT. METHODS: We performed a genome-wide association study of LVMWT measured from the cardiovascular magnetic resonance examinations of 42 176 European individuals. We evaluated the genetic relationship between LVMWT and HCM by performing pairwise analysis using the data from the Hypertrophic Cardiomyopathy Registry in which the controls were randomly selected from UK Biobank individuals not included in the cardiovascular magnetic resonance sub-study. RESULTS: Twenty-one genetic loci were discovered at P<5×10-8. Several novel candidate genes were identified including PROX1, PXN, and PTK2, with known functional roles in myocardial growth and sarcomere organization. The LVMWT genetic risk score is predictive of HCM in the Hypertrophic Cardiomyopathy Registry (odds ratio per SD: 1.18 [95% CI, 1.13-1.23]) with pairwise analyses demonstrating a moderate genetic correlation (rg=0.53) and substantial loci overlap (19/21). CONCLUSIONS: Our findings provide novel insights into the genetic underpinning of LVMWT and highlight its shared genetic background with HCM, supporting future endeavours to elucidate the genetic etiology of HCM.
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Cardiomiopatia Hipertrófica , Hipertrofia Ventricular Esquerda , Humanos , Bancos de Espécimes Biológicos , Cardiomiopatia Hipertrófica/diagnóstico , Cardiomiopatia Hipertrófica/genética , Estudo de Associação Genômica Ampla , Hipertrofia Ventricular Esquerda/diagnóstico , Hipertrofia Ventricular Esquerda/genética , Reino UnidoRESUMO
The discovery of genetic loci associated with complex diseases has outpaced the elucidation of mechanisms of disease pathogenesis. Here we conducted a genome-wide association study (GWAS) for coronary artery disease (CAD) comprising 181,522 cases among 1,165,690 participants of predominantly European ancestry. We detected 241 associations, including 30 new loci. Cross-ancestry meta-analysis with a Japanese GWAS yielded 38 additional new loci. We prioritized likely causal variants using functionally informed fine-mapping, yielding 42 associations with less than five variants in the 95% credible set. Similarity-based clustering suggested roles for early developmental processes, cell cycle signaling and vascular cell migration and proliferation in the pathogenesis of CAD. We prioritized 220 candidate causal genes, combining eight complementary approaches, including 123 supported by three or more approaches. Using CRISPR-Cas9, we experimentally validated the effect of an enhancer in MYO9B, which appears to mediate CAD risk by regulating vascular cell motility. Our analysis identifies and systematically characterizes >250 risk loci for CAD to inform experimental interrogation of putative causal mechanisms for CAD.
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Doença da Artéria Coronariana , Humanos , Doença da Artéria Coronariana/genética , Estudo de Associação Genômica AmplaRESUMO
Type 2 diabetes (T2D) is an important heritable risk factor for coronary artery disease (CAD), the risk of both diseases being increased by metabolic syndrome (MS). With the availability of large-scale genome-wide association data, we aimed to elucidate the genetic burden of CAD risk in T2D predisposed individuals within the context of MS and their shared genetic architecture. Mendelian randomization (MR) analyses supported a causal relationship between T2D and CAD [odds ratio (OR) = 1.13 per log-odds unit 95% confidence interval (CI): 1.10-1.16; p = 1.59 × 10-17 ]. Simultaneously adjusting MR analyses for the effects of the T2D instrument including blood pressure, dyslipidaemia, and obesity attenuated the association between T2D and CAD (OR = 1.07, 95% CI: 1.04-1.11). Bayesian locus-overlap analysis identified 44 regions with the same causal variant underlying T2D and CAD genetic signals (FDR < 1%) at a posterior probability >0.7; five (MHC, LPL, ABO, RAI1 and MC4R) of these regions contain genome-wide significant (p < 5 × 10-8 ) associations for both traits. Given the small effect sizes observed in genome-wide association studies for complex diseases, even with 44 potential target regions, this has implications for the likely magnitude of CAD risk reduction that might be achievable by pure T2D therapies.
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Doença da Artéria Coronariana , Diabetes Mellitus Tipo 2 , Teorema de Bayes , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/genética , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Análise da Randomização Mendeliana , Polimorfismo de Nucleotídeo Único , Fatores de RiscoRESUMO
Air travel is generally safe, but the flight environment poses unique physiologic challenges such as relative hypoxia that may trigger adverse myocardial or pulmonary outcomes. To optimize health outcomes, communication must take place between the traveler, family physician, and airline carrier when there is any doubt about fitness for air travel. Travelers should carry current medications in their original containers and a list of their medical conditions and allergies; they should adjust timing of medications as needed based on time zone changes. The Hypoxia Altitude Simulation Test can be used to determine specific in-flight oxygen requirements for patients who have pulmonary complications or for those for whom safe air travel remains in doubt. Patients with pulmonary conditions who are unable to walk 50 m or for those whose usual oxygen requirements exceed 4 L per minute should be advised not to fly. Trapped gases that expand at high altitude can cause problems for travelers with recent surgery; casting; ear, nose, and throat issues; or dental issues. Insulin requirements may change based on duration and direction of travel. Travelers can minimize risk for deep venous thrombosis by adequately hydrating, avoiding alcohol, walking for 10 to 15 minutes every two hours of travel time, and performing seated isometric exercises. Wearing compression stockings can prevent asymptomatic deep venous thrombosis and superficial venous thrombosis for flights five hours or longer in duration. Physicians and travelers can review relevant pretravel health information, including required and recommended immunizations, health concerns, and other travel resources appropriate for any destination worldwide on the Centers for Disease Control and Prevention travel website.
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Viagem Aérea , Nível de Saúde , Humanos , Hipóxia/prevenção & controle , Fatores de Risco , Trombose Venosa/prevenção & controleRESUMO
Hypertrophic cardiomyopathy (HCM) is a common, serious, genetic heart disorder. Rare pathogenic variants in sarcomere genes cause HCM, but with unexplained phenotypic heterogeneity. Moreover, most patients do not carry such variants. We report a genome-wide association study of 2,780 cases and 47,486 controls that identified 12 genome-wide-significant susceptibility loci for HCM. Single-nucleotide polymorphism heritability indicated a strong polygenic influence, especially for sarcomere-negative HCM (64% of cases; h2g = 0.34 ± 0.02). A genetic risk score showed substantial influence on the odds of HCM in a validation study, halving the odds in the lowest quintile and doubling them in the highest quintile, and also influenced phenotypic severity in sarcomere variant carriers. Mendelian randomization identified diastolic blood pressure (DBP) as a key modifiable risk factor for sarcomere-negative HCM, with a one standard deviation increase in DBP increasing the HCM risk fourfold. Common variants and modifiable risk factors have important roles in HCM that we suggest will be clinically actionable.
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Cardiomiopatia Hipertrófica/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Idoso , Pressão Sanguínea/genética , Miosinas Cardíacas/genética , Proteínas de Transporte/genética , Estudos de Casos e Controles , Forminas/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Heterozigoto , Humanos , Pessoa de Meia-Idade , Cadeias Pesadas de Miosina/genética , Fatores de Risco , Sarcômeros/genética , Adulto JovemRESUMO
BACKGROUND: Over the last 10 years, there have been over 3300 genome-wide association studies (GWAS). Almost every GWAS study provides a Manhattan plot either as a main figure or in the supplement. Several software packages can generate a Manhattan plot, but they are all limited in the extent to which they can annotate gene-names, allele frequencies, and variants having high impact on gene function or provide any other added information or flexibility. Furthermore, in a conventional Manhattan plot, there is no way of distinguishing a locus identified due to a single variant with very significant p-value from a locus with multiple variants which appear to be in a haplotype block having very similar p-values. RESULTS: Here we present a software tool written in R, which generates a transposed Manhattan plot along with additional features like variant consequence and minor allele frequency to annotate the plot and addresses these limitations. The software also gives flexibility on how and where the user wants to display the annotations. The software can be downloaded from CRAN repository and also from the GitHub project page. CONCLUSIONS: We present a major step up to the existing conventional Manhattan plot generation tools. We hope this form of display along with the added annotations will bring more insight to the reader from this new Manhattan++ plot.
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Estudo de Associação Genômica Ampla/estatística & dados numéricos , Anotação de Sequência Molecular/estatística & dados numéricos , Genoma , Humanos , Polimorfismo de Nucleotídeo Único , SoftwareRESUMO
Epidemiological studies suggest a positive association between coronary artery disease (CAD) and late-onset Alzheimer's disease (LOAD). This large-scale genetic study brings together 'big data' resources to examine the causal impact of genetic determinants of CAD on risk of LOAD. A two-sample Mendelian randomization approach was adopted to estimate the causal effect of CAD on risk of LOAD using summary data from 60,801 CAD cases from CARDIoGRAMplusC4D and 17,008 LOAD cases from the IGAP Consortium. Additional analyses assessed the independent relevance of genetic associations at the APOE locus for both CAD and LOAD. Higher genetically determined risk of CAD was associated with a slightly higher risk of LOAD (Odds Ratio (OR) per log-odds unit of CAD [95% CI]: 1.07 [1.01-1.15]; p = 0.027). However, after exclusion of the APOE locus, the estimate of the causal effect of CAD for LOAD was attenuated and no longer significant (OR 0.94 [0.88-1.01]; p = 0.072). This Mendelian randomization study indicates that the APOE locus is the chief determinant of shared genetic architecture between CAD and LOAD, and suggests a lack of causal relevance of CAD for risk of LOAD after exclusion of APOE.
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Doença de Alzheimer/genética , Doença da Artéria Coronariana/genética , Predisposição Genética para Doença , Análise da Randomização Mendeliana , Idoso , Doença de Alzheimer/complicações , Doença de Alzheimer/epidemiologia , Doença de Alzheimer/fisiopatologia , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/fisiopatologia , Feminino , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Medição de Risco , Fatores de RiscoRESUMO
Genome-wide association studies (GWAS) in coronary artery disease (CAD) had identified 66 loci at 'genome-wide significance' (P < 5 × 10-8) at the time of this analysis, but a much larger number of putative loci at a false discovery rate (FDR) of 5% (refs. 1,2,3,4). Here we leverage an interim release of UK Biobank (UKBB) data to evaluate the validity of the FDR approach. We tested a CAD phenotype inclusive of angina (SOFT; ncases = 10,801) as well as a stricter definition without angina (HARD; ncases = 6,482) and selected cases with the former phenotype to conduct a meta-analysis using the two most recent CAD GWAS. This approach identified 13 new loci at genome-wide significance, 12 of which were on our previous list of loci meeting the 5% FDR threshold, thus providing strong support that the remaining loci identified by FDR represent genuine signals. The 304 independent variants associated at 5% FDR in this study explain 21.2% of CAD heritability and identify 243 loci that implicate pathways in blood vessel morphogenesis as well as lipid metabolism, nitric oxide signaling and inflammation.
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Doença da Artéria Coronariana/genética , Loci Gênicos/genética , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla/métodos , Estudos de Associação Genética/métodos , Estudos de Associação Genética/normas , Estudos de Associação Genética/estatística & dados numéricos , Estudo de Associação Genômica Ampla/normas , Estudo de Associação Genômica Ampla/estatística & dados numéricos , Genótipo , Sistemas de Informação em Saúde/normas , Sistemas de Informação em Saúde/estatística & dados numéricos , Humanos , Metanálise como Assunto , Fenótipo , Polimorfismo de Nucleotídeo Único , Reprodutibilidade dos Testes , Fatores de Risco , Reino UnidoRESUMO
The family Syngnathidae is a large and diverse clade of morphologically unique bony fishes, with 57 genera and 300 described species of seahorses, pipefishes, pipehorses, and seadragons. They primarily inhabit shallow coastal waters in temperate and tropical oceans, and are characterized by a fused jaw, male brooding, and extraordinary crypsis. Phylogenetic relationships within the Syngnathidae remain poorly resolved due to lack of generic taxon sampling, few diagnostic morphological characters, and limited molecular data. The phylogenetic placement of the threatened, commercially exploited seahorses remains a topic of intense interest, with conflicting topologies based on morphology and predominantly mitochondrial genetic data. In this study, we integrate eight nuclear and mitochondrial markers and 17 morphological characters to investigate the phylogenetic structure of the family Syngnathidae at the generic level. We include 91 syngnathid species representing 48 of the 57 recognized genera, all major ocean basins, and a broad array of temperate and tropical habitats including rocky and coral reefs, sand and silt, mangroves, seagrass beds, estuaries, and rivers. Maximum likelihood and Bayesian analyses of 5160bp from eight loci produced high congruence among alternate topologies, defining well-supported and sometimes novel clades. We present a hypothesis that confirms a deep phylogenetic split between lineages with trunk- or tail-brood pouch placement, and provides significant new insights into the morphological evolution and biogeography of this highly derived fish clade. Based on the fundamental division between lineages - the tail brooding "Urophori" and the trunk brooding "Gastrophori" - we propose a revision of Syngnathidae classification into only two subfamilies: the Nerophinae and the Syngnathinae. We find support for distinct principal clades within the trunk-brooders and tail-brooders, the latter of which include seahorses, seadragons, independent lineages of pipehorses, and clades that originated in southern Australia and the Western Atlantic. We suggest the seahorse genus Hippocampus is of Indo-Pacific origin and its sister clade is an unexpected grouping of several morphologically disparate Indo-Pacific genera, including the Pacific pygmy pipehorses. Taxonomic revision is required for multiple genera, particularly to reflect deep evolutionary splits in nominal lineages from the Atlantic versus the Indo-Pacific.
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Peixes/classificação , Peixes/genética , Variação Genética , Filogenia , Animais , Sequência de Bases , Teorema de Bayes , Núcleo Celular/genética , Evolução Molecular , Peixes/anatomia & histologia , Masculino , FilogeografiaRESUMO
BACKGROUND: Biomarkers of inflammation and altered coagulation are of increasing interest as predictors of chronic disease and mortality in HIV patients, as well as the use of risk stratification scores such as the Framingham index and the Veterans Aging Cohort Study (VACS) score. METHODS: Demographic and laboratory data for 252 HIV patients were assessed for their relationship with 5 biomarkers: hsCRP, D-dimer, Cystatin C, IL-6 and TNF-alpha. Analysis of variance was used to model the association between the number of elevated biomarkers patients had and their Framingham 10 year cardiovascular risk and VACS scores. RESULTS: 87% of patients were male and 75.7% were virally suppressed (HIV RNA <48 copies/ml). The median and interquartile ranges for each biomarker were: hsCRP 1.65 ug/mL (0.73, 3.89), D-dimer 0.17 ug/mL (0.09, 0.31), Cystatin C 0.87 mg/L (0.78, 1.01), IL-6 2.13 pg/mL (1.3, 3.59), TNF-alpha 4.65 pg/mL (3.5, 5.97). 62.6% of patients had more than one biomarker >75th percentile, while 18.6% had three or more elevated biomarkers. Increased age, cigarette smoking, CD4 counts of <200 cells/mm3, Framingham scores and VACS scores were most strongly associated with elevations in biomarkers. When biomarkers were used to predict the Framingham and VACS scores, those with a higher number of elevated biomarkers had higher mean VACS scores, with a similar but less robust finding for Framingham scores. CONCLUSIONS: Despite viral suppression and immunological stability, biomarkers of inflammation and coagulation remain elevated in a significant number of patients with HIV and are associated with higher scores on risk stratification indices.
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Biomarcadores/sangue , Infecções por HIV/complicações , Inflamação/sangue , Medição de Risco/métodos , Adulto , Coagulação Sanguínea , Contagem de Linfócito CD4 , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/virologia , Estudos de Coortes , Estudos Transversais , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Infecções por HIV/sangue , Humanos , Inflamação/virologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Vermont , VeteranosRESUMO
Existing knowledge of genetic variants affecting risk of coronary artery disease (CAD) is largely based on genome-wide association study (GWAS) analysis of common SNPs. Leveraging phased haplotypes from the 1000 Genomes Project, we report a GWAS meta-analysis of â¼185,000 CAD cases and controls, interrogating 6.7 million common (minor allele frequency (MAF) > 0.05) and 2.7 million low-frequency (0.005 < MAF < 0.05) variants. In addition to confirming most known CAD-associated loci, we identified ten new loci (eight additive and two recessive) that contain candidate causal genes newly implicating biological processes in vessel walls. We observed intralocus allelic heterogeneity but little evidence of low-frequency variants with larger effects and no evidence of synthetic association. Our analysis provides a comprehensive survey of the fine genetic architecture of CAD, showing that genetic susceptibility to this common disease is largely determined by common SNPs of small effect size.
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Doença da Artéria Coronariana/genética , Genoma Humano , Estudo de Associação Genômica Ampla , Humanos , FenótipoRESUMO
While myriad molecular formats for bispecific antibodies have been examined to date, the simplest structures are often based on the scFv. Issues with stability and manufacturability in scFv-based bispecific molecules, however, have been a significant hindrance to their development, particularly for high-concentration, stable formulations that allow subcutaneous delivery. Our aim was to generate a tetravalent bispecific molecule targeting two inflammatory mediators for synergistic immune modulation. We focused on an scFv-Fc-scFv format, with a flexible (A4T)3 linker coupling an additional scFv to the C-terminus of an scFv-Fc. While one of the lead scFvs isolated directly from a naïve library was well-behaved and sufficiently potent, the parental anti-CXCL13 scFv 3B4 required optimization for affinity, stability, and cynomolgus ortholog cross-reactivity. To achieve this, we eschewed framework-based stabilizing mutations in favor of complementarity-determining region (CDR) mutagenesis and re-selection for simultaneous improvements in both affinity and thermal stability. Phage-displayed 3B4 CDR-mutant libraries were used in an aggressive "hammer-hug" selection strategy that incorporated thermal challenge, functional, and biophysical screening. This approach identified leads with improved stability and>18-fold, and 4,100-fold higher affinity for both human and cynomolgus CXCL13, respectively. Improvements were exclusively mediated through only 4 mutations in VL-CDR3. Lead scFvs were reformatted into scFv-Fc-scFvs and their biophysical properties ranked. Our final candidate could be formulated in a standard biopharmaceutical platform buffer at 100 mg/ml with<2% high molecular weight species present after 7 weeks at 4 °C and viscosity<15 cP. This workflow has facilitated the identification of a truly manufacturable scFv-based bispecific therapeutic suitable for subcutaneous administration.
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Anticorpos Biespecíficos/genética , Regiões Determinantes de Complementaridade/genética , Engenharia de Proteínas , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/metabolismo , Animais , Bacteriófagos/genética , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Injeções Subcutâneas , Biblioteca de Peptídeos , Estabilidade Proteica , Ratos , Anticorpos de Cadeia Única/genética , TemperaturaRESUMO
Liquid chromatography tandem mass spectrometry (LC-MS/MS) has been shown to be a viable tool for preclinical pharmacokinetic (PK) analysis of monoclonal antibody (mAb) therapeutics. This work describes free and total PK assays for the mAb PF-00547,659 in serum of ulcerative colitis patients in a First-In-Human study [Vermeire, S. et al. Gut2011, 60 (8), 1068-1075]. The assay to measure free PF-00547,659 used immuno-enrichment with a biotinylated anti-idiotypic antibody and streptavidin magnetic beads. The total assay used enrichment by protein G magnetic beads. Following elution of PF-00547,659 from the beads, addition of an extended sequence stable isotope labeled peptide and trypsin digestion, a proteotypic peptide derived from the CDR region of the light chain of PF-00547,659 was quantified by LC-MS/MS. The free assay had a calibration range from 7.03 ng/mL to 450 ng/mL. The assay was precise and accurate with interbatch imprecision <16.5%, and interbatch inaccuracy <13.7% at all concentrations investigated during assay qualification. Results from LC-MS/MS methodologies are compared with historical immunoassay data originally acquired during the course of the clinical study. PK parameter estimates were highly correlated between the two analytical approaches. This work provides precedence that immunoaffinity LC-MS/MS can effectively be used to measure the serum concentrations of mAb therapeutics in clinical studies.
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Anticorpos Monoclonais/farmacocinética , Anticorpos Monoclonais/uso terapêutico , Cromatografia Líquida/métodos , Mucoproteínas/imunologia , Espectrometria de Massas em Tandem/métodos , Anticorpos Monoclonais/imunologia , Humanos , ImunoensaioRESUMO
Advances in recombinant antibody technology and protein engineering have provided the opportunity to reduce antibodies to their smallest binding domain components and have concomitantly driven the requirement for devising strategies to increase serum half-life to optimise drug exposure, thereby increasing therapeutic efficacy. In this study, we adopted an immunization route to raise picomolar affinity shark immunoglobulin new antigen receptors (IgNARs) to target human serum albumin (HSA). From our model shark species, Squalus acanthias, a phage display library encompassing the variable binding domain of IgNAR (VNAR) was constructed, screened against target, and positive clones were characterized for affinity and specificity. N-terminal and C-terminal molecular fusions of our lead hit in complex with a naïve VNAR domain were expressed, purified and exhibited the retention of high affinity binding to HSA, but also cross-selectivity to mouse, rat and monkey serum albumin both in vitro and in vivo. Furthermore, the naïve VNAR had enhanced pharmacokinetic (PK) characteristics in both N- and C-terminal orientations and when tested as a three domain construct with naïve VNAR flanking the HSA binding domain at both the N and C termini. Molecules derived from this platform technology also demonstrated the potential for clinical utility by being available via the subcutaneous route of delivery. This study thus demonstrates the first in vivo functional efficacy of a VNAR binding domain with the ability to enhance PK properties and support delivery of multifunctional therapies.
Assuntos
Produtos Biológicos/farmacocinética , Receptores de Antígenos/metabolismo , Proteínas Recombinantes de Fusão/farmacocinética , Anticorpos de Domínio Único/metabolismo , Animais , Afinidade de Anticorpos , Especificidade de Anticorpos , Desenho de Fármacos , Haplorrinos , Humanos , Camundongos , Engenharia de Proteínas/métodos , Ratos , Receptores de Antígenos/genética , Proteínas Recombinantes de Fusão/genética , Albumina Sérica/imunologia , Tubarões , Anticorpos de Domínio Único/genéticaRESUMO
As part of a 2010 conference entitled "Patients and Populations: Public Health in Medical Education," faculty from four U.S. medical schools (Case Western Reserve University, Harvard Medical School, the University of Colorado School of Medicine, and the University of Vermont College of Medicine), collaborated on a workshop to help other medical educators develop scenario-based learning experiences as practical, engaging, and effective mechanisms for teaching public health principles to medical school students. This paper describes and compares four different medical schools' experiences using a similar pandemic exercise scenario, discusses lessons learned, and suggests a curricular framework for medical schools adding such exercises to their population health curriculum. Different strategies to create realistic scenarios and engage students, including use of professionals and stakeholders from the community, are described.