Perfil HLA na população do Rio Grande do Sul : diversidade genética e potencial impacto na gestão de transplantes de medula óssea

Os genes HLA são os mais polimórficos do genoma humano e suas frequências alélicas variam entre populações de diferentes regiões e etnias pelo mundo. Assim, os genes HLA têm sido usados como marcadores genéticos em estudos de genética de populações e história do povoamento humano. Este trabalho teve como objetivo realizar a caracterização HLA da população gaúcha, visando contribuir no melhor entendimento da ancestralidade e miscigenação da população do Rio Grande do Sul, bem como na efetividade na gestão de programas de transplante de medula óssea. Foi realizado um estudo com dados genéticos HLA de doadores de medula óssea do Rio Grande do Sul (RS), onde foi avaliada a correspondência do perfil HLA dentro e entre grupos étnicos com a autodeclaração de cor de pele – sistema oficial adotado pelo IBGE para caracterização étnica da população. Os resultados indicam que o sistema HLA é um melhor indicador de ancestralidade que a auto avaliação baseada em cor de pele, sendo esta uma ferramenta ineficiente para a caracterização da população. Para a caracterização da variação molecular HLA em diferentes regiões do RS, foram realizadas análises em dados genéticos HLA de mais de 90 mil doadores de medula óssea. Os resultados não indicaram correlação entre a variação HLA e a divisão geográfica oficial definida pelo IBGE no RS. Por outro lado, foram observadas diferenças a respeito da etnia. Além disso, quando comparada com as populações parentais e com dados históricos, a população rio-grandense apresenta maior similaridade genética com suas populações parentais correspondentes. Este estudo apresenta uma caracterização completa da variação genética HLA no RS. Análise espacial e georeferenciamento de dados genéticos HLA e de doenças autoimunes no estado também foram realizadas. Os resultados indicam uma estrutura genética HLA compatível com a história de colonização do RS, onde é possível observar diferenciação entre as regiões que sofreram processo de colonização distintos, como as regiões sudoeste e metropolitana em relação à região central e noroeste. Análises espaciais sobre dados de internação de doenças autoimunes foram realizadas, revelando agrupamentos para artrite reumatoide e doença de Crohn na região centro-oriental do estado e para esclerose múltipla agrupamento na região centro-ocidental. A avaliação da correlação entre a frequência alélica e a ocorrência de doenças autoimunes indicou uma correlação significativa entre o alelo HLA-B*08 e artrite reumatoide. O mapeamento genético de populações tem grande relevância econômica na formulação de campanhas e políticas de saúde pública, contribuindo no planejamento e ajuste de ações clínicas, bem como informar e educar profissionais e público. Nesta pesquisa são apresentados extensivos dados referentes à caracterização HLA da população rio-grandense levando em consideração dados históricos e geográficos. Os resultados aqui apresentados podem ter utilidade na otimização de campanhas de recrutamento de medula óssea bem como contribui com o entendimento do contexto histórico e demográfico do estado do Rio Grande do Sul. As estratégias e ferramentas utilizadas nesta pesquisa poderão servir como base para futuros estudos em outras populações.HLA genes are the most polymorphic of the human genome and their allelic frequencies vary among populations from different regions and ethnicities throughout the world. Thus, HLA genes has been used as genetic markers in population genetics studies and in the history of human settlement. This work aimed to perform the HLA characterization of Rio Grande do Sul (RS) population, looking forward to contribute in the understanding of the ancestry and miscegenation of the Rio Grande do Sul population, as well as in the effectiveness in the management of bone marrow transplantation programs. A study with HLA genetic data of bone marrow donors from Rio Grande do Sul was performed, evaluating the correspondence of the HLA profile within and between ethnic groups with the self-declaration of skin color – official system adopted by the IBGE for population ethnic characterization. The results indicate that the HLA system is a better indicator of ancestry than the self-evaluation based on skin color, this being an inefficient tool for the characterization of the population. For the characterization of HLA molecular variation in different RS regions, analyzes were performed on HLA genetic data of more than 90,000 bone marrow donors. The results did not indicate correlation between the HLA variation and the official geographic division defined by IBGE in RS. On the other hand, major differences were observed regarding. In addition, when compared to the parental populations and with historical data, local populations from Rio Grande do Sul were found to be genetically similar to their corresponding parental European populations. This study provides a thorough characterization of the HLA genetic variation in RS. Spatial and georeferencing analysis of HLA genetic data and autoimmune diseases in the state were also performed. The results indicate a HLA genetic structure compatible with the RS history of colonization, where it is possible to observe differentiation among regions that underwent different colonization processes, such as the southwest and metropolitan regions in relation to the central and northwestern regions. Spatial analyzes with data from hospitalization of autoimmune diseases were performed, revealing clusters for rheumatoid arthritis and Crohn's disease in the central-oriental region of the state and for multiple sclerosis clustering in the central-occidental region. The correlation analysis between allelic frequency and the occurrence of autoimmune diseases indicated a significant correlation between the HLA-B*08 allele and rheumatoid arthritis. Genetic mapping of populations has great economic relevance in the formulation of public health campaigns and policies, contributing to the planning and adjustment of clinical actions, as well as informing and educating professionals and the public. In this research, extensive data referring to the HLA characterization of the Rio Grande population taking into account historical and geographic data are presented. The results presented here may be useful in the optimization of bone marrow recruitment campaigns as well as contribute to the understanding of the historical and demographic context of Rio Grande do Sul state. The strategies and tools used in this research may be useful as a basis for future studies in other populations

Molecular mechanisms of Zika virus teratogenesis from animal studies : a systematic review protocol

Background: Due to the diversity of studies in animal models reporting that molecular mechanisms are involved in the teratogenic effect of the Zika virus (ZIKV), the objective of the present study is to evaluate the methodological quality of these studies, as well as to demonstrate which genes and which molecular pathways are affected by ZIKV in different animal models. Methods: This search will be performed in four databases: PubMed/MEDLINE, EMBASE, Web of Science, and Scopus, as well as in the grey literature. The studies selection process will be reported through the PRISMA Statement diagram model. All studies describing the molecular mechanisms possibly involved in the development of malformations caused by embryonic/fetal ZIKV exposure in animal models with an appropriate control group and methodology will be included (including, for instance, randomized and non-randomized studies). All animals used as experimental models for ZIKV teratogenesis may be included as long as exposure to the virus occurred during the embryonic/fetal period. From the selected studies, data will be extracted using a previously prepared standard form. Bias risk evaluation will be conducted following the SYRCLE’s Risk of Bias tool. All data obtained will be tabulated and organized by outcomes (morphological and molecular). Discussion: With the proposed systematic review, we expect to present results about the methodological quality of the published studies with animal models that investigated the molecular mechanisms involved in the teratogenic effect of ZIKV, as well as to show the studies with greater reliability

Prevalências ao nascimento de anomalias congênitas entre nascidos vivos no estado do Maranhão de 2001 a 2016: análise temporal e espacial

Objectives: To analyze the prevalence at birth and the spatial and temporal distribution of congenital anomalies (CAs) among live births in the state of Maranhão in the years 2001 to 2016. To describe demographic, gestational and neonatal variables of interest. Methods: Ecological, population-based study, using secondary data from the Information System on Live Births (SINASC). Annual prevalence of total and per group CAs was calculated. Spatial analyzes used the calculation of Local Indicators of Spatial Association and the Moran I Index and interactive maps were generated. Demographic, gestational and neonatal variables of interest available at SINASC were described in the group of newborns with CAs. Results: 1,831,830 live births, 6,110 with CAs (33.4/10,000) were included. Higher frequencies have occurred in more recent years. Spatial clusters have been observed in specific years. The prevalence of births of babies with CAs was different between categories of variables considered as risk factors for this outcome. Conclusion: The prevalence at birth of total CAs was lower than expected for the human species for major defects (3%). The temporal peak of records in 2015/2016 is probably related to the increase in CAs caused by gestational infection by Zika virus. The spatial clusters were probably due to variations at random due to the small number of births as they are not repeated in other years. Studies like this are the basis for the establishment of CA surveillance programs.Objetivos: Analisar as prevalências ao nascimento e a distribuição espacial e temporal das anomalias congênitas entre nascidos vivos no estado do Maranhão nos anos de 2001 a 2016. Descrever variáves de interesse demográficas, gestacionais e neonatais. Métodos: Estudo ecológico, de base populacional, a partir de dados secundários do Sistema de Informações sobre Nascidos Vivos. Foram calculadas prevalências ao nascimento anuais de ACs totais e por grupos. Análises espaciais utilizaram o cálculo de Indicadores de Associação Espacial Locais e o Índice de Moran I e mapas interativos foram gerados. Variáveis de interesse demográficos, gestacionais e neonatais disponíveis no SINASC foram descritas no grupo dos recém-nascidos com ACs. Resultados: Foram incluídos 1.831.830 nascidos vivos, 6.110 com anomalias congênitas (33,4/10.000). Maiores frequências ocorreram nos anos mais recentes. Aglomerados espaciais foram observados em anos específicos. As prevalências de nascidos vivos com anomalias foi diferente entre categorias de variáveis consideradas como fatores de risco para este desfecho. Conclusão: A prevalência ao nascimento de nascidos com anomalias congênitas  foi  inferior ao esperado para defeitos maiores na espécie humana (3%).  O pico temporal de registros em 2015/2016 está provavelmente relacionado ao aumento de microcefalia causada pela infecção gestacional por vírus Zika. Os aglomerados espaciais provavelmente se deveram a variações ao acaso pelo número pequeno de nascimentos pois não se repetem em outros anos. Estudos como este são base para o estabelecimento de programas de vigilância de defeitos congênitos

HLA haplotypes and differential regional mortality caused by COVID-19 in Brazil: an ecological study based on a large bone marrow donor bank dataset

The coronavirus disease 2019 (COVID-19) mortality rates varied among the states of Brazil during the course of the pandemics. The human leukocyte antigen (HLA) is a critical component of the antigen presentation pathway. Individuals with different HLA genotypes may trigger different immune responses against pathogens, which could culminate in different COVID-19 responses. HLA genotypes are variable, especially in the highly admixed Brazilian population. In this ecological study, we aimed to investigate the correlation between HLA haplotypes and the different regional distribution of COVID-19 mortality in Brazil. HLA data was obtained from 4,148,713 individuals registered in The Brazilian Voluntary Bone Marrow Donors Registry. COVID-19 data was retrieved from epidemiological bulletins issued by State Health Secretariats via Brazil’s Ministry of Health from February/2020 to July/2022. We found a positive significant correlation between the HLA-A*01~B*08~DRB1*03 haplotype and COVID-19 mortality rates when we analyzed data from 26 states and the Federal District. This result indicates that the HLAA*01~B*08~DRB1*03 haplotype may represent an additional risk factor for dying due to COVID-19. This haplotype should be further studied in other populations for a better understanding of the variation in COVID-19 outcomes across the world

Neurodevelopment in children exposed to Zika in utero : clinical and molecular aspects

Five years after the identification of Zika virus as a human teratogen, we reviewed the early clinical manifestations, collectively called congenital Zika syndrome (CZS). Children with CZS have a very poor prognosis with extremely low performance in motor, cognitive, and language development domains, and practically all feature severe forms of cerebral palsy. However, these manifestations are the tip of the iceberg, with some children presenting milder forms of deficits. Additionally, neurodevelopment can be in the normal range in the majority of the non-microcephalic children born without brain or eye abnormalities. Vertical transmission and the resulting disruption in development of the brain are much less frequent when maternal infection occurs in the second half of the pregnancy. Experimental studies have alerted to the possibility of other behavioral outcomes both in prenatally infected children and in postnatal and adult infections. Cofactors play a vital role in the development of CZS and involve genetic, environmental, nutritional, and social determinants leading to the asymmetric distribution of cases. Some of these social variables also limit access to multidisciplinary professional treatment

Association between Genetic Variants in NOS2 and TNF Genes with Congenital Zika Syndrome and Severe Microcephaly

Zika virus (ZIKV) causes Congenital Zika Syndrome (CZS) in individuals exposed prenatally. Here, we investigated polymorphisms in VEGFA, PTGS2, NOS3, TNF, and NOS2 genes as risk factors to CZS. Forty children with CZS and forty-eight children who were in utero exposed to ZIKV infection, but born without congenital anomalies, were evaluated. Children with CZS were predominantly infected by ZIKV in the first trimester (p < 0.001) and had mothers with lower educational level (p < 0.001) and family income (p < 0.001). We found higher risk of CZS due the allele rs2297518[A] of NOS2 (OR = 2.28, CI 95% 1.17–4.50, p = 0.015). T allele and TT/CT genotypes of the TNF rs1799724 and haplotypes associated with higher expression of TNF were more prevalent in children with CZS and severe microcephaly (p = 0.029, p = 0.041 and p = 0.030, respectively). Our findings showed higher risk of CZS due ZIKV infection in the first trimester and suggested that polymorphisms in NOS2 and TNF genes affect the risk of CZS and severe microcephaly

Microcephaly prevalence after the 2015 to 2016 Zika outbreak in Tangará da Serra, Brazil: a population-based study

Objective: Prenatal infection with the Zika virus (ZIKV) can lead to congenital Zika syndrome (CZS), characterized by microcephaly and brain injury. However, there are questions regarding the prevalence of microcephaly/CZS after the ZIKV outbreak in defined geographic areas. This study aimed to identify adverse outcomes in live births of fetuses exposed in utero to the ZIKV, compared to unexposed births, as well as maternal sociodemographic, delivery, and birth characteristics. Methods: Here, we conducted a cross-sectional observational study to investigate the characteristics of all live births in the city of Tangará da Serra, Mato Grosso, Brazil, in 2016, after the outbreak of ZIKV infection in late 2015. All live births of children to women residing in the municipality of Tangará da Serra between January 1 and December 31, 2016, were evaluated, and head circumference was measured at birth and after 24 hours. Children born with microcephaly or a maternal history of confirmed or suspected prenatal ZIKV infection were evaluated by a multidisciplinary team. The outcomes of the exposed and non-exposed children were compared. Prevalence ratios and their respective 95% confidence intervals were calculated for sociodemographic, delivery, and live birth characteristics. Results: Of 1,441 live births, 106 (7.3%) were from mothers with confirmed or highly probable exposure to ZIKV. The prevalence of severe congenital microcephaly (41.7/10,000) in Tangará da Serra in 2016 was ten-fold higher than that in Latin America before 2015. Conclusion: This study may serve as a model to investigate possible outbreaks of infections in a defined geographical space in the future

Análise de polimorfismos da família p53 e sua via regulatória como fatores de risco para aneuploidia

A aneuploidia é o distúrbio cromossômico mais comum em humanos e ocorre em pelo menos 5% de todas as gestações clinicamente reconhecidas. A trissomia é o tipo de aneuploidia mais frequente, sendo a trissomia do 21 a mais comum entre os nascidos vivos. A não-disjunção meiótica é a principal causa da trissomia livre do 21, sendo responsável por 95% dos indivíduos afetados. Apesar de poder ocorrer em qualquer um dos genitores, em 90% dos casos a não-disjunção meiótica é de origem materna. A idade materna é o único fator comprovadamente ligado à aneuploidia em humanos. Estudos recentes indicam que a família gênica p53 exerce importante função como reguladora de processos de reprodução e desenvolvimento, limitando a propagação de células aneuplóides. Sua disfunção ou desequilíbrio pode levar a anomalias patológicas em humanos. Este estudo teve como objetivo avaliar polimorfismos nos genes da família p53 e sua via regulatória como fatores de risco para Síndrome de Down (SD) em um estudo caso-controle. Foram analisados os polimorfismos c.215G>C do gene TP53, c.43-4742T>G do gene TP63, c.-30G>A e c.-20C>T do gene TP73, c.14+309T>G do gene MDM2, c.753+572C>T do gene MDM4 e c.2719-234G>A do gene USP7 em 263 mães de portadores da SD e 196 mães de crianças sem malformações. As frequências dos polimorfismos foram determinadas pelo método TaqMan de discriminação alélica através de PCR real-time. A distribuição alélica e genotípica dos polimorfismos testados foi similar entre os grupos caso e controle, e não apresentou diferença estatisticamente significativa quando avaliada individualmente, mesmo quando controlado para idade materna. Entretanto, quando testada a interação gene-gene, a combinação dos alelos TP53 C e MDM2 G, e TP53 C e USP7 A foi associada a um aumento no risco de ter filho com SD (OR = 1,84 e 1,77; 95% IC; P C (P72R), TP63 c.43-4742T>G, TP73 4 c.-30G>A and 14 c.-20C>T, MDM2 c.14+309T>G (SNP309), MDM4 c.753+572C>T and USP7 c.2719-234G>A in 263 mothers with DS and 196 mothers of children without malformations. The frequencies of polymorphisms were determined using the TaqMan allelic discrimination by real-time PCR. The allelic and genotypic distribution of these polymorphisms tested was similar between case and control groups, and did not differ statistically when evaluated individually, even when controlling for maternal age. However, when assessed the gene-gene interactions, the combination of the alleles TP53 C and MDM2 G, and TP53 C and USP7 A was associated with an increased risk of having a child with Down Syndrome (OR = 1.84 and 1.77, 95% CI, P <0.007 and 0.018 respectively). Our results suggest that, although the evaluated polymorphisms are not associated with the risk of risk of 21 trisomy, the combined alleles may have a synergistic effect in a multifactorial way. In this study, we search by different susceptibility factors that could predispose to aneuploid births. This is the first study to establish a relationship between polymorphisms in the p53 gene family and its regulatory pathway as a risk factor for aneuploidy of 21

Análise de polimorfismos da família p53 e sua via regulatória como fatores de risco para aneuploidia

A aneuploidia é o distúrbio cromossômico mais comum em humanos e ocorre em pelo menos 5% de todas as gestações clinicamente reconhecidas. A trissomia é o tipo de aneuploidia mais frequente, sendo a trissomia do 21 a mais comum entre os nascidos vivos. A não-disjunção meiótica é a principal causa da trissomia livre do 21, sendo responsável por 95% dos indivíduos afetados. Apesar de poder ocorrer em qualquer um dos genitores, em 90% dos casos a não-disjunção meiótica é de origem materna. A idade materna é o único fator comprovadamente ligado à aneuploidia em humanos. Estudos recentes indicam que a família gênica p53 exerce importante função como reguladora de processos de reprodução e desenvolvimento, limitando a propagação de células aneuplóides. Sua disfunção ou desequilíbrio pode levar a anomalias patológicas em humanos. Este estudo teve como objetivo avaliar polimorfismos nos genes da família p53 e sua via regulatória como fatores de risco para Síndrome de Down (SD) em um estudo caso-controle. Foram analisados os polimorfismos c.215G>C do gene TP53, c.43-4742T>G do gene TP63, c.-30G>A e c.-20C>T do gene TP73, c.14+309T>G do gene MDM2, c.753+572C>T do gene MDM4 e c.2719-234G>A do gene USP7 em 263 mães de portadores da SD e 196 mães de crianças sem malformações. As frequências dos polimorfismos foram determinadas pelo método TaqMan de discriminação alélica através de PCR real-time. A distribuição alélica e genotípica dos polimorfismos testados foi similar entre os grupos caso e controle, e não apresentou diferença estatisticamente significativa quando avaliada individualmente, mesmo quando controlado para idade materna. Entretanto, quando testada a interação gene-gene, a combinação dos alelos TP53 C e MDM2 G, e TP53 C e USP7 A foi associada a um aumento no risco de ter filho com SD (OR = 1,84 e 1,77; 95% IC; P C (P72R), TP63 c.43-4742T>G, TP73 4 c.-30G>A and 14 c.-20C>T, MDM2 c.14+309T>G (SNP309), MDM4 c.753+572C>T and USP7 c.2719-234G>A in 263 mothers with DS and 196 mothers of children without malformations. The frequencies of polymorphisms were determined using the TaqMan allelic discrimination by real-time PCR. The allelic and genotypic distribution of these polymorphisms tested was similar between case and control groups, and did not differ statistically when evaluated individually, even when controlling for maternal age. However, when assessed the gene-gene interactions, the combination of the alleles TP53 C and MDM2 G, and TP53 C and USP7 A was associated with an increased risk of having a child with Down Syndrome (OR = 1.84 and 1.77, 95% CI, P <0.007 and 0.018 respectively). Our results suggest that, although the evaluated polymorphisms are not associated with the risk of risk of 21 trisomy, the combined alleles may have a synergistic effect in a multifactorial way. In this study, we search by different susceptibility factors that could predispose to aneuploid births. This is the first study to establish a relationship between polymorphisms in the p53 gene family and its regulatory pathway as a risk factor for aneuploidy of 21