Association of the genetic ancestry with resistant hypertension in the ReHOT (Resistant Hypertension Optimal Treatment) randomized study.

Resistant hypertension (RH) is defined as uncontrolled blood pressure despite treatment with three or more antihypertensive medications, including, if tolerated, a diuretic in adequate doses. It has been widely known that race is associated with blood pressure control. However, intense debate persists as to whether this is solely explained by unadjusted socioeconomical variables or genetic variation. In this scenario, the main aim was to evaluate the association between genetic ancestry and resistant hypertension in a large sample from a multicenter trial of stage II hypertension, the ReHOT study. Samples from 1,358 patients were analyzed, of which 167 were defined as resistant hypertensive. Genetic ancestry was defined using a panel of 192 polymorphic markers. The genetic ancestry was similar in resistant (52.0% European, 36.7% African and 11.3% Amerindian) and nonresistant hypertensive patients (54.0% European, 34.4% African and 11.6% Amerindian) (p > 0.05). However, we observed a statistically suggestive association of African ancestry with resistant hypertension in brown patient group. In conclusion, increased African genetic ancestry was not associated with RH in Brazilian patients from a prospective randomized hypertension clinical trial.

The Duffy null genotype is associated with a lower level of CCL2, leukocytes and neutrophil count but not with the clinical outcome of HTLV-1 infection.

Purpose. Chemokines are important in the immune response against viral infections, and may play a role in human T-lymphotropic virus 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) pathogenesis. Polymorphisms in the Duffy antigen receptor for chemokines (DARC), such as rs12075 (A>G; FY*B>FY*A) and rs281477 (-46T>C; GATA-1 box) may influence circulating concentrations of proinflammatory chemokines. We investigate whether Duffy genotypes influence the HTLV-1 proviral load (PVL) level, HTLV-1 infection outcome and chemokine concentrations in HTLV-1 asymptomatic carriers (AC=162), HAM/TSP patients (HAM=135) and seronegative individuals (SN=71).Methodology. Quantification of plasmatic IL8, CCL2 and CCL5 were performed by flow cytometry and Duffy genotypes were investigated by real-time PCR. HTLV-1 PVL was quantified in peripheral blood. To control for spurious association, individual ancestry profiles in AC and HAM groups were investigated.Results/Key findings. PVL and IL8 level were significantly higher in the HAM group than in the AC group, but were not associated with Duffy genotypes. The highest CCL2 and CCL5 levels were seen in the SN group, and there was no difference when comparing the infected groups. The level of CCL5 was not associated with Duffy genotypes. The polymorphism -46 C/C that abrogates the DARC expression on the erythrocytes was significantly associated with lower levels of CCL2, neutrophil and white blood cell (WBC) counts in HTLV-1-infected individuals.Conclusion. We conclude that although the Duffy null genotype was associated with leukopenia, neutropenia and lower levels of CCL2, the data do not suggest the influence of Duffy genotypes on the neurologic outcome of HTLV-1 infection, but may be a confounding factor in comparison HTLV-1-infected populations with different ancestries, especially when defining inflammatory biomarkers.

Duffy blood group system: New genotyping method and distribution in a Brazilian extra-Amazonian population.

Duffy blood group system is of interest in several fields of science including transfusion medicine, immunology and malariology. Although some methods have been developed for Duffy polymorphism genotyping, not all of them have been sufficiently described and validated, and all present limitations. At the same time, the frequency of Duffy alleles and antigens in some densely populated regions of the world are still missing. In this study we present new tests for genotyping the major alleles of the Duffy blood system and describe Duffy alleles and antigens in blood donors and transfusion-dependent patients in Minas Gerais, Brazil. A simple and reproducible strategy was devised for Duffy genotyping based on real-time PCR that included SNPs rs12075 and rs2814778. No significant differences between the allele frequencies were observed comparing blood donors and patients. Among the blood donors, the phenotype Fy(a-b+) was the most common and the Fy(a-b-) phenotype, associated with populations of African descent, was remarkably less common among subjects who self-identified as black in comparison to other ethnoracial categories. However, the African ancestry estimated by molecular markers was significantly higher in individuals with the allele associated to the Duffy null phenotype. The genotyping method presented may be useful to study Duffy genotypes accurately in different contexts and populations. The results suggest a reduced risk of alloimmunization for Duffy antigens and increased susceptibility for malaria in Minas Gerais, considering the high frequency of Duffy-positive individuals.

Padrozação de estratégia molecular custo-efetiva para rastreamento de fenótipos eritrocitários e plaquetários raros em doadores de sangue visando à organização de banco de doadores raros no estado de São Paulo / Cost-effective molecular strategy standardization for screening of erythrocyte phenotypes and rare platelet in blood donors aiming at the organization of a rare donor bank in the state of São Paulo

OBJETIVOS: 1- Padronizar a genotipagem em larga escala para determinação de antígenos eritrocitários e plaquetários pela plataforma de OpenArray®em doadores de sangue. 2- Elaboração de software para registro destes doadores, com interface com o equipamento de genotipagem. METODOLOGIA: Extração automatizada de DNA e genotipagem através demicroarranjos líquidos (OpenArray®) para 32 alelos codificantes de antígenos eritrocitários e plaquetários. RESULTADOS: Foi realizada a genotipagem de 5487 doadores para os antígenos propostos, de forma completamente interfaceada e automatizada. O ensaio customizado de Open Array® mostrou-se acurado e de rápida execução. Elaborou-se software próprio para interfaceamento dos resultados da genotipagem e busca dos genótipos. CONCLUSÃO: Padronizou-se estratégia efetiva para rastreamento de doadores de sangue com fenótipos raros. A automação de todas as etapas experimentais e o interfaceamento completo dos dados minimizaram os erros humanos e aumentaram a rapidez do processo descrito, que pode ser aplicado como estratégia de genotipagem de doadores de todo o Estado de São Paulo.

Increasing The Genetic Admixture of Available Lines of Human Pluripotent Stem Cells.

Human pluripotent stem cells (hPSCs) may significantly improve drug development pipeline, serving as an in vitro system for the identification of novel leads, and for testing drug toxicity. Furthermore, these cells may be used to address the issue of differential drug response, a phenomenon greatly influenced by genetic factors. This application depends on the availability of hPSC lines from populations with diverse ancestries. So far, it has been reported that most lines of hPSCs derived worldwide are of European or East Asian ancestries. We have established 23 lines of hPSCs from Brazilian individuals, and we report the analysis of their genomic ancestry. We show that embryo-derived PSCs are mostly of European descent, while induced PSCs derived from participants of a national-wide Brazilian cohort study present high levels of admixed European, African and Native American genomic ancestry. Additionally, we use high density SNP data and estimate local ancestries, particularly those of CYP genes loci. Such information will be of key importance when interpreting variation among cell lines with respect to cellular phenotypes of interest. The availability of genetically admixed lines of hPSCs will be of relevance when setting up future in vitro studies of drug response.

Genomic ancestry as a predictor of haemodynamic profile in heart failure.

OBJECTIVE: The aim of this study is to assess the association between genetic ancestry, self-declared race and haemodynamic parameters in patients with chronic heart failure (HF). METHODS: Observational, cross-sectional study. Eligible participants were aged between 18 and 80 years; ejection fraction was ≤50%. Patients underwent genetic analysis of ancestry informative markers, echocardiography and impedance cardiography (ICG). Race was determined by self-classification into two groups: white and non-white. Genomic ancestry was estimated using a panel of 101 348 polymorphic markers and three continental reference populations (European, African and Native American). RESULTS: Our study included 362 patients with HF between August 2012 and August 2014. 123 patients with HF declared themselves as white and 234 patients declared themselves as non-white. No statistically significant differences were found regarding the ICG parameters according to self-declared race. The Amerindian ancestry was positively correlated with systolic time ratio (r=0.109, p<0.05). The thoracic fluid content index (r=0.124. p<0.05), E wave peak (r=0.127. p<0.05) and E/e' ratio (r=0.197. p<0.01) were correlated positively with African ancestry. In multiple linear regression, African ancestry remained associated with the E/e' ratio, even after adjustment to risk factors. CONCLUSIONS: The African genetic ancestry was associated with worse parameters of diastolic function; the Amerindian ancestry correlated with a worse pattern of ventricular contractility, while self-declared colour was not helpful to infer haemodynamic profiles in HF. TRIALS REGISTRATION NUMBER: NTC02043431.

Smoking and Female Sex: Independent Predictors of Human Vascular Smooth Muscle Cells Stiffening.

AIMS: Recent evidence shows the rigidity of vascular smooth muscle cells (VSMC) contributes to vascular mechanics. Arterial rigidity is an independent cardiovascular risk factor whose associated modifications in VSMC viscoelasticity have never been investigated. This study's objective was to evaluate if the arterial rigidity risk factors aging, African ancestry, female sex, smoking and diabetes mellitus are associated with VMSC stiffening in an experimental model using a human derived vascular smooth muscle primary cell line repository. METHODS: Eighty patients subjected to coronary artery bypass surgery were enrolled. VSMCs were extracted from internal thoracic artery fragments and mechanically evaluated using Optical Magnetic Twisting Cytometry assay. The obtained mechanical variables were correlated with the clinical variables: age, gender, African ancestry, smoking and diabetes mellitus. RESULTS: The mechanical variables Gr, G'r and G"r had a normal distribution, demonstrating an inter-individual variability of VSMC viscoelasticity, which has never been reported before. Female sex and smoking were independently associated with VSMC stiffening: Gr (apparent cell stiffness) p = 0.022 and p = 0.018, R2 0.164; G'r (elastic modulus) p = 0.019 and p = 0.009, R2 0.184 and G"r (dissipative modulus) p = 0.011 and p = 0.66, R2 0.141. CONCLUSION: Female sex and smoking are independent predictors of VSMC stiffening. This pro-rigidity effect represents an important element for understanding the vascular rigidity observed in post-menopausal females and smokers, as well as a potential therapeutic target to be explored in the future. There is a significant inter-individual variation of VSMC viscoelasticity, which is slightly modulated by clinical variables and probably relies on molecular factors.

Butyrylcholinesterase genetic variants: association with cocaine dependence and related phenotypes.

OBJECTIVE: The search for genetic vulnerability factors in cocaine dependence has focused on the role that neuroplasticity plays in addiction. However, like many other drugs, the ability of an individual to metabolize cocaine can also influence susceptibility to dependence. Butyrylcholinesterase (BChE) metabolizes cocaine, and genetic variants of the BChE gene (BCHE) alter its catalytic activity. Therefore, we hypothesize that cocaine users with polymorphisms in BCHE can show diverse addictive behaviors due to differences in effective plasma concentrations of cocaine. Those polymorphisms might also influence users to prefer one of the two main preparations (crack or powder cocaine), despite having equal access to both. The present work investigates polymorphisms in BCHE and if those genetic variants constitute risk factors for cocaine dependence and for crack cocaine use. METHODS: A total of 1,436 individuals (698 cocaine-dependent patients and 738 controls) were genotyped for three single nucleotide polymorphisms (SNPs) in BCHE: rs1803274, rs4263329, and rs4680662. RESULTS: For rs4263329, a nominal difference was found between cases and controls. For rs1803274 (the functional SNP), a statistically significant difference was found between patients who used crack cocaine exclusively and those who used only powder cocaine (P = 0.027; OR = 4.36; 95% CI = 1.18-16.04). Allele frequencies and genotypes related to other markers did not differ between cases and controls or between the two cocaine subgroups. CONCLUSIONS: Our findings suggest that the AA genotype of rs1803274 is a risk factor for crack cocaine use, which is more addictive than powder cocaine use. Further studies are needed in order to confirm this preliminary result and clarify the role of BCHE and its variants in cocaine dependence.