A Pregnancy and Childhood Epigenetics Consortium (PACE) meta-analysis highlights potential relationships between birth order and neonatal blood DNA methylation.

Higher birth order is associated with altered risk of many disease states. Changes in placentation and exposures to in utero growth factors with successive pregnancies may impact later life disease risk via persistent DNA methylation alterations. We investigated birth order with Illumina DNA methylation array data in each of 16 birth cohorts (8164 newborns) with European, African, and Latino ancestries from the Pregnancy and Childhood Epigenetics Consortium. Meta-analyzed data demonstrated systematic DNA methylation variation in 341 CpGs (FDR adjusted P < 0.05) and 1107 regions. Forty CpGs were located within known quantitative trait loci for gene expression traits in blood, and trait enrichment analysis suggested a strong association with immune-related, transcriptional control, and blood pressure regulation phenotypes. Decreasing fertility rates worldwide with the concomitant increased proportion of first-born children highlights a potential reflection of birth order-related epigenomic states on changing disease incidence trends.

Association of Pre-S/S and Polymerase Mutations with Acute and Chronic Hepatitis B Virus Infections in Patients from Rio de Janeiro, Brazil.

Several hepatitis B virus (HBV)-related factors, including the viral load, genotype, and genomic mutations, have been linked to the development of liver diseases. Therefore, in this study we aimed to investigate the influence of HBV genetic variability during acute and chronic infection phases. A real-time nested PCR was used to detect HBV DNA in all samples (acute, n = 22; chronic, n = 49). All samples were sequenced for phylogenetic and mutation analyses. Genotype A, sub-genotype A1, was the most common genotype in the study population. A total of 190 mutations were found in the pre-S/S gene area and the acute profile revealed a greater number of nucleotide mutations (p < 0.05). However, both profiles contained nucleotide mutations linked to immune escape and an increased risk of hepatocellular carcinomas (acute, A7T; chronic, A7Q). Furthermore, 17 amino acid substitutions were identified in the viral polymerase region, including the drug resistance mutations lamivudine and entecavir (rtL180M), with statistically significant differences between the mutant and wild type strains. Owing to the natural occurrence of these mutations, it is important to screen for resistance mutations before beginning therapy.

Cutaneous and acral melanoma cross-OMICs reveals prognostic cancer drivers associated with pathobiology and ultraviolet exposure.

Ultraviolet radiation (UV) is causally linked to cutaneous melanoma, yet the underlying epigenetic mechanisms, known as molecular sensors of exposure, have not been characterized in clinical biospecimens. Here, we integrate clinical, epigenome (DNA methylome), genome and transcriptome profiling of 112 cutaneous melanoma from two multi-ethnic cohorts. We identify UV-related alterations in regulatory regions and immunological pathways, with multi-OMICs cancer driver potential affecting patient survival. TAPBP, the top gene, is critically involved in immune function and encompasses several UV-altered methylation sites that were validated by targeted sequencing, providing cost-effective opportunities for clinical application. The DNA methylome also reveals non UV-related aberrations underlying pathological differences between the cutaneous and 17 acral melanomas. Unsupervised epigenomic mapping demonstrated that non UV-mutant cutaneous melanoma more closely resembles acral rather than UV-exposed cutaneous melanoma, with the latter showing better patient prognosis than the other two forms. These gene-environment interactions reveal translationally impactful mechanisms in melanomagenesis.

Update of the global distribution of human gammaherpesvirus 8 genotypes.

Human gammaherpesvirus 8 (HHV-8) consists of six major clades (A-F) based on the genetic sequence of the open reading frame (ORF)-K1. There are a few conflicting reports regarding the global distribution of the different HHV-8 genotypes. This study aimed to determine the global distribution of the different HHV-8 genotypes based on phylogenetic analysis of the ORF-K1 coding region using sequences published in the GenBank during 1997-2020 and construct a phylogenetic tree using the maximum likelihood algorithm with the GTR + I + G nucleotide substitution model. A total of 550 sequences from 38 countries/origins were analysed in this study. Genotypes A and C had similar global distributions and were prevalent in Africa and Europe. Genotype B was prevalent in Africa. Of the rare genotypes, genotype D was reported in East Asia and Oceania and genotype E in South America, while genotype F was prevalent in Africa. The highest genotypic diversity was reported in the American continent, with Brazil housing five HHV-8 genotypes (A, B, C, E, and F). In this study, we present update of the global distribution of HHV-8 genotypes, providing a basis for future epidemiological and evolutionary studies of HHV-8.

Comprehensive Analysis of Clinically Significant Hepatitis B Virus Mutations in Relation to Genotype, Subgenotype and Geographic Region.

Hepatitis B virus (HBV) is a highly variable DNA virus due to its unique life cycle, which involves an error-prone reverse transcriptase. The high substitution rate drives the evolution of HBV by generating genetic variants upon which selection operates. HBV mutants with clinical implications have been documented worldwide, indicating the potential for spreading and developing their own epidemiology. However, the prevalence of such mutants among the different HBV genotypes and subgenotypes has not been systematically analyzed. In the current study, we performed large-scale analysis of 6,479 full-length HBV genome sequences from genotypes A-H, with the aim of gaining comprehensive insights into the relationships of relevant mutations associated with immune escape, antiviral resistance and hepatocellular carcinoma (HCC) development with HBV (sub)genotypes and geographic regions. Immune escape mutations were detected in 10.7% of the sequences, the most common being I/T126S (1.8%), G145R (1.2%), M133T (1.2%), and Q129R (1.0%). HBV genotype B showed the highest rate of escape mutations (14.7%) while genotype H had no mutations (P < 0.001). HCC-associated mutations were detected in 33.7% of the sequences, with significantly higher frequency of C1653T, T1753V and A1762T/G1764A in genotype G than C (P < 0.001). The overall frequencies of lamivudine-, telbivudine-, adefovir-, and entecavir-resistant mutants were 7.3, 7.2, 0.5, and 0.2%, respectively, while only 0.05% showed reduced susceptibility to tenofovir. In particular, the highest frequency of lamivudine-resistant mutations was observed in genotype G and the lowest frequency in genotype E (32.5 and 0.3%; P < 0.001). The prevalence of HBV mutants was also biased by geographic location, with North America identified as one of the regions with the highest rates of immune escape, antiviral resistance, and HCC-associated mutants. The collective findings were discussed in light of natural selection and the known characteristics of HBV (sub)genotypes. Our data provide relevant information on the prevalence of clinically relevant HBV mutations, which may contribute to further improvement of diagnostic procedures, immunization programs, therapeutic protocols, and disease prognosis.

Introduction of human gammaherpesvirus 8 genotypes A, B, and C into Brazil from multiple geographic regions

Variations in the open reading frame (ORF) K1 gene sequence of human gammaherpesvirus 8 (HHV-8) has led to the identification of 6 major genotypic clades (A, B, C, D, E, and F) in specimens isolated from around the world. These clades exhibit clear clustering among individuals in different ethnic groups and from different geographic regions. The human population of Brazil varies greatly in ethnicity because of multiple immigration events from Africa, Europe, Asia, and indigenous communities. However, there is scant information about the HHV-8 genotypes currently circulating in Brazil. Here, we describe HHV-8 genotypic diversity in isolates from Brazilian HIV-infected patients living with Kaposi's sarcoma (KS) by analysis of the complete ORF-K1 region. We also identified the most likely geographic origins of these different Brazilian genotypes. We extracted HHV-8 DNA (24 positive samples) from individuals with HIV/KS from the states of São Paulo and Rio de Janeiro, amplified the ORF-K1 gene using nested PCR (about 870 base pairs), performed sequencing and phylogenetic analysis, and then calculated the mean genetic distances of Brazilian sequences from sequences in other regions of the world (523 sequences analyzed). Phylogenetic analysis showed that genotypes C, A, and B were present in 45.8 %, 29.2 % and 25 % of the isolates from Brazil, respectively. These isolates grouped into separate clades, rather than a single monophyletic cluster. Mean genetic distance analyses suggested that these genotypes were introduced into the Brazil multiple times from different geographical regions. HHV-8/A isolates appear to be from Ukraine, Russia, and the Tartar ethnic group; HHV-8/B isolates appear to be from Congo and Democratic Republic of the Congo; and HHV-8/C isolates appear to be from Australia, Algeria, England, and French Guiana. These results contribute to a better understanding of the genetic diversity and origins of HHV-8 strains circulating in Brazil, and will provide a foundation for further epidemiological and evolutionary studies of HHV-8

Introduction of human gammaherpesvirus 8 genotypes A, B, and C into Brazil from multiple geographic regions.

Variations in the open reading frame (ORF) K1 gene sequence of human gammaherpesvirus 8 (HHV-8) has led to the identification of 6 major genotypic clades (A, B, C, D, E, and F) in specimens isolated from around the world. These clades exhibit clear clustering among individuals in different ethnic groups and from different geographic regions. The human population of Brazil varies greatly in ethnicity because of multiple immigration events from Africa, Europe, Asia, and indigenous communities. However, there is scant information about the HHV-8 genotypes currently circulating in Brazil. Here, we describe HHV-8 genotypic diversity in isolates from Brazilian HIV-infected patients living with Kaposi's sarcoma (KS) by analysis of the complete ORF-K1 region. We also identified the most likely geographic origins of these different Brazilian genotypes. We extracted HHV-8 DNA (24 positive samples) from individuals with HIV/KS from the states of São Paulo and Rio de Janeiro, amplified the ORF-K1 gene using nested PCR (about 870 base pairs), performed sequencing and phylogenetic analysis, and then calculated the mean genetic distances of Brazilian sequences from sequences in other regions of the world (523 sequences analyzed). Phylogenetic analysis showed that genotypes C, A, and B were present in 45.8 %, 29.2 % and 25 % of the isolates from Brazil, respectively. These isolates grouped into separate clades, rather than a single monophyletic cluster. Mean genetic distance analyses suggested that these genotypes were introduced into the Brazil multiple times from different geographical regions. HHV-8/A isolates appear to be from Ukraine, Russia, and the Tartar ethnic group; HHV-8/B isolates appear to be from Congo and Democratic Republic of the Congo; and HHV-8/C isolates appear to be from Australia, Algeria, England, and French Guiana. These results contribute to a better understanding of the genetic diversity and origins of HHV-8 strains circulating in Brazil, and will provide a foundation for further epidemiological and evolutionary studies of HHV-8.

The First Complete Genome Sequences of Hepatitis C Virus Subtype 2b from Latin America: Molecular Characterization and Phylogeographic Analysis.

The hepatitis C virus (HCV) has remarkable genetic diversity and exists as eight genotypes (1 to 8) with distinct geographic distributions. No complete genome sequence of HCV subtype 2b (HCV-2b) is available from Latin American countries, and the factors underlying its emergence and spread within the continent remain unknown. The present study was conducted to determine the first full-length genomic sequences of HCV-2b isolates from Latin America and reconstruct the spatial and temporal diversification of this subtype in Brazil. Nearly complete HCV-2b genomes isolated from two Brazilian patients were obtained by direct sequencing of long PCR fragments and analyzed together with reference sequences using the Bayesian coalescent and phylogeographic framework approaches. The two HCV-2b genomes were 9318 nucleotides (nt) in length (nt 37-9354). Interestingly, the long RT-PCR technique was able to detect co-circulation of viral variants that contained an in-frame deletion of 2022 nt encompassing E1, E2, and p7 proteins. Spatiotemporal reconstruction analyses suggest that HCV-2b had a single introduction in Brazil during the early 1980s, displaying an epidemic history characterized by a low and virtually constant population size until the present time. These results coincide with epidemiological data in Brazil and may explain the low national prevalence of this subtype.

Reconstruction of the spatial and temporal dynamics of hepatitis B virus genotype D in the Americas.

Hepatitis B virus (HBV) genotype D (HBV/D) is globally widespread, and ten subgenotypes (D1 to D10) showing distinct geographic distributions have been described to date. The evolutionary history of HBV/D and its subgenotypes, for which few complete genome sequences are available, in the Americas is not well understood. The main objective of the current study was to determine the full-length genomic sequences of HBV/D isolates from Brazil and frequency, origin and spread of HBV/D subgenotypes in the Americas. Complete HBV/D genomes isolated from 39 Brazilian patients infected with subgenotypes D1 (n = 1), D2 (n = 10), D3 (n = 27), and D4 (n = 1) were sequenced and analyzed together with reference sequences using the Bayesian coalescent and phylogeographic framework. A search for HBV/D sequences available in GenBank revealed 209 complete and 926 partial genomes from American countries (Argentina, Brazil, Canada, Chile, Colombia, Cuba, Haiti, Martinique, Mexico, USA and Venezuela), with the major circulating subgenotypes identified as D1 (26%), D2 (17%), D3 (36%), D4 (21%), and D7 (1%) within the continent. The detailed evolutionary history of HBV/D in the Americas was investigated by using different evolutionary time scales. Spatiotemporal reconstruction analyses using short-term substitution rates suggested times of the most recent common ancestor for the American HBV/D subgenotypes coincident with mass migratory movements to Americas during the 19th and 20th centuries. In particular, significant linkages between Argentina and Syria (D1), Brazil and Central/Eastern Europe (D2), USA and India (D2), and Brazil and Southern Europe (D3) were estimated, consistent with historical and epidemiological data.

Hepatitis B virus genotypes A1, A2 and E in Cape Verde: Unequal distribution through the islands and association with human flows.

Hepatitis B virus (HBV) diversity has not been previously studied in Cape Verde. The archipelago was discovered in 1460 by Portuguese explorers, who brought African slaves to colonise the islands. In this study, we investigated the HBV characteristics from 183 HBsAg-positive Cape Verdean individuals. Phylogenetic analysis of the pre-S/S region and the full-length genomes revealed 54 isolates with HBV/A1 (57%), 21 with HBV/A2 (22%), 19 with HBV/E (20%), and one with HBV/D (1%). HBV genotypes and subgenotypes were unequally distributed through the islands. In São Vicente, the main northern island, most isolates (84%) belonged to the African-originated HBV/A1, with the remaining isolates belonging to HBV/A2, which is prevalent in Europe. Interestingly, the HBV/A1 isolates from São Vicente were closely related to Brazilian sequences into the Asian-American clade, which suggests the dissemination of common African ancestors through slave trade. In contrast, in Santiago and nearby southern islands, where a recent influx from different populations circulates, a higher diversity of HBV was observed: HBV/A1 (40%); HBV/E (32%); HBV/A2 (28%); and HBV/D (1%). HBV/E is a recent genotype disseminated in Africa that was absent in the era of the slave trade. African and European human flows at different times of the history may explain the HBV diversity in Cape Verde. The possible origin and specifics of each HBV genotype circulating in Cape Verde are discussed.

Complete genome sequence of a hepatitis B virus isolate of genotype D2, subtype adrq+, from Brazil.

Hepatitis B virus (HBV) has been classified into 10 distinct serological subtypes of the surface antigen (HBsAg) that can be predicted by sequencing of the corresponding S gene. HBV genotype D usually displays determinants of subtypes ayw2 or ayw3. On the other hand, subtype adrq+ has been found exclusively in association with genotype C. Here, we describe the first HBV genome (isolate BR32) belonging to genotype D with the serological subtype adrq+. This isolate had a genome length of 3,062 nucleotides (nt), and no recombination events were observed in the BR32 genome that could explain the occurrence of the subtype adr in a genotype D isolate. Analysis of the quasispecies population revealed that 28 out of 30 clones (93%) were of subtype adrq+, while the subtypes of the two remaining could not be determined, since they contained an S residue (instead of K or R) at position 122 of HBsAg. These results will contribute to further epidemiological and evolutionary studies of HBV.

Prevalence, Risk Behaviors, and Virological Characteristics of Hepatitis B Virus Infection in a Group of Men Who Have Sex with Men in Brazil: Results from a Respondent-Driven Sampling Survey.

BACKGROUND: Men who have sex with men (MSM) are at increased risk of exposure to hepatitis B virus (HBV) compared with the general population. This study aims to assess the epidemiological and virological characteristics of HBV infection in a sample of MSM in Brazil, where data are scarce. METHODS: A cross-sectional study was conducted among MSM in the City of Goiânia, Central Brazil, from March to November 2014, using Respondent-Driven Sampling (RDS). After signing the consent form, participants were interviewed and a blood sample collected. All samples were tested for HBV serological markers and HBV DNA. HBV nucleotide sequence analysis was also performed. RESULTS: A total of 522 MSM were recruited in the study. The prevalence of HBV infection (current or past [presence of anti-HBc marker]) was 15.4% (95% CI: 8.7-25.8) and the rate of HBsAg carriers was 0.6% (95% CI: 0.2-1.6). About 40% (95% CI: 32.3-48.8) of the participants had serological evidence of previous HBV vaccination (reactive for isolated anti-HBs). In addition, 44.3% (95% CI: 36.1-52.9) were seronegative for all HBV markers. Age over 25 years old, receptive anal intercourse, previous sex with women, and history of sexually transmitted infections (STIs) were factors associated with HBV infection. HBV DNA was detected only in HBsAg-positive individuals. HBV isolates were classified into genotype A (subgenotypes A1 and A2), and some mutations were identified throughout the genome. Therefore, occult HBV infection was not observed in the study population. CONCLUSIONS: Public health strategies should be improved for the MSM population in order to prevent HBV and other STIs, as well as to provide appropriate management of patients with active infections.

Full-genome sequences of hepatitis B virus subgenotype D3 isolates from the Brazilian Amazon Region.

The Brazilian Amazon Region is a highly endemic area for hepatitis B virus (HBV). However, little is known regarding the genetic variability of the strains circulating in this geographical region. Here, we describe the first full-length genomes of HBV isolated in the Brazilian Amazon Region; these genomes are also the first complete HBV subgenotype D3 genomes reported for Brazil. The genomes of the five Brazilian isolates were all 3,182 base pairs in length and the isolates were classified as belonging to subgenotype D3, subtypes ayw2 (n = 3) and ayw3 (n = 2). Phylogenetic analysis suggested that the Brazilian sequences are not likely to be closely related to European D3 sequences. Such results will contribute to further epidemiological and evolutionary studies of HBV.

Full-genome sequences of hepatitis B virus subgenotype D3 isolates from the Brazilian Amazon Region

The Brazilian Amazon Region is a highly endemic area for hepatitis B virus (HBV). However, little is known regarding the genetic variability of the strains circulating in this geographical region. Here, we describe the first full-length genomes of HBV isolated in the Brazilian Amazon Region; these genomes are also the first complete HBV subgenotype D3 genomes reported for Brazil. The genomes of the five Brazilian isolates were all 3,182 base pairs in length and the isolates were classified as belonging to subgenotype D3, subtypes ayw2 (n = 3) and ayw3 (n = 2). Phylogenetic analysis suggested that the Brazilian sequences are not likely to be closely related to European D3 sequences. Such results will contribute to further epidemiological and evolutionary studies of HBV.