34 research outputs found

    Risk factors for hepatitis B virus infection in Rio de Janeiro, Brazil

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    BACKGROUND: Despite international efforts to prevent hepatitis B virus (HBV) infection through global vaccination programs, new cases are still being reported throughout the world. METHODS: To supply data that might assist in improving preventive measures and national surveillance for HBV infection, a cross-sectional study was conducted among individuals referred to the Brazilian National Reference Center for Viral Hepatitis (Rio de Janeiro) during a two-year period. Reported risk factors among infected subjects ("HBV-positive") were compared to those of subjects never exposed ("HBV-negative") to HBV. Two subgroups were further identified within the HBV-positive group, "acute" infection and "non-acute" infection. RESULTS: A total of 1,539 subjects were tested for HBV, of which 616 were HBV-positive (79 acute infection and 537 non-acute infection). HBV-positive subjects were more likely to be of male gender (63% versus 47%); and to report multiple sexual partners (12% versus 6%) and illicit drug use (IDU and/or intranasal cocaine use) (6% versus 3%). Among the HBV-positive subgroups, age differed significantly, with 48% being under 30 years of age in subjects acutely infected compared to 17% in those with non-acute infection. CONCLUSIONS: The association of multiple sexual partners with past HBV infection and the age distribution of currently infected subjects suggest that sexual transmission played a major role in the transmission of HBV in this study population. Thus, vaccination during adolescence should be considered

    Antibody dynamics and spontaneous viral clearance in patients with acute hepatitis C infection in Rio de Janeiro, Brazil

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    Submitted by Sandra Infurna ([email protected]) on 2017-01-18T10:31:05Z No. of bitstreams: 1 clara_yoshida_etal_IOC_2011.pdf: 146042 bytes, checksum: 8ec889224534b76d755828a99d0660c2 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2017-01-18T10:59:52Z (GMT) No. of bitstreams: 1 clara_yoshida_etal_IOC_2011.pdf: 146042 bytes, checksum: 8ec889224534b76d755828a99d0660c2 (MD5)Made available in DSpace on 2017-01-18T10:59:52Z (GMT). No. of bitstreams: 1 clara_yoshida_etal_IOC_2011.pdf: 146042 bytes, checksum: 8ec889224534b76d755828a99d0660c2 (MD5) Previous issue date: 2011Innsbruck Medical University. Department of Medical Statistics, Informatics and Health Economics. Innsbruck, Austria.Harvard Medical School. Boston, MA, USA / Massachussets General Hospital. Division of Infectious Diseases. Boston, MA, USA.Harvard Medical School. Boston, MA, USA / Massachussets General Hospital. Gastrointestinal Unit. Boston, MA, USA.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. LaboratĂłrio de Hepatites Virais. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. LaboratĂłrio de Hepatites Virais. Rio de Janeiro, RJ. Brasil.LaboratĂłrio Central de SaĂşde PĂşblica Noel Nutels. DivisĂŁo de Hepatites. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. LaboratĂłrio de Hepatites Virais. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. LaboratĂłrio de Hepatites Virais. Rio de Janeiro, RJ. Brasil / Universidade Federal do Estado do Rio de Janeiro. Hospital Universitário GaffrĂ©e Guinle. Unidade de Hepatologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. LaboratĂłrio de Desenvolvimento TecnolĂłgico em Virologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. LaboratĂłrio de Hepatites Virais. Rio de Janeiro, RJ. Brasil.Universitätsklinikum Eppendorf. Medizinische Klinik I. Hamburg, Germany.Fondation Merieux. Emerging Pathogens Laboratory. Lyon, France.University of Innsbruck. Institute of Statistics. Innsbruck, Austria.National Institute on Aging. Gerontology Research Center. Baltimore, USA.Innsbruck Medical University. Department of Medical Statistics, Informatics and Health Economics. Innsbruck, Austria.Innsbruck Medical University. Department of Medical Statistics, Informatics and Health Economics. Innsbruck, Austria.Innsbruck Medical University. Department of Medical Statistics, Informatics and Health Economics. Innsbruck, Austria.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. LaboratĂłrio de Hepatites Virais. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. LaboratĂłrio de Hepatites Virais. Rio de Janeiro, RJ. Brasil.Background: The anti-HCV antibody response has not been well characterized during the early phase of HCV infection and little is known about its relationship to the clinical course during this period. Methods: We analyzed serial anti-HCV antibodies longitudinally obtained from a prospective cohort of 65 patients with acute HCV infection by using a microparticle enzyme immunoassay AxSYM HCV 3.0 (Abbott Diagnostics) during the first 12 months from HCV acquisition in Rio de Janeiro, Brazil. Spontaneous viral clearance (SVC) was defined as undetectable HCV RNA in serum, in the absence of treatment, for three consecutive HCV PCR tests within 12-months of follow-up. Results: Baseline antibody values were similar among patient groups with self-limiting HCV evolution (n = 34) and persistent viremia (n = 31) [median (interquartile range) signal/cut-off ratio (s/co) 78.7 (60.7-93.8) vs. 93.9 (67.8- 111.9), p = 0.26]. During 12-months follow-up, patients with acute spontaneous resolving HCV infection showed significantly lower serial antibody response in comparison to individuals progressing to chronic infection [median (interquartile range) s/co 62.7 (35.2-85.0) vs. 98.4 (70.4-127.4), p < 0.0001]. In addition, patients with self-limiting HCV evolution exhibited an expeditious, sharp decline of serial antibody values after SVC in comparison to those measured before SVC [median (interquartile range) s/co 56.0 (25.4-79.3) vs. 79.4 (66.3-103.0), p < 0.0001]. Conclusion: Our findings indicate a rapid short-term decline of antibody values in patients with acute spontaneous resolving HCV infection

    Early Transcriptional Divergence Marks Virus-Specific Primary Human CD8+ T Cells in Chronic versus Acute Infection.

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    Distinct molecular pathways govern the differentiation of CD8+ effector T cells into memory or exhausted T cells during acute and chronic viral infection, but these are not well studied in humans. Here, we employed an integrative systems immunology approach to identify transcriptional commonalities and differences between virus-specific CD8+ T cells from patients with persistent and spontaneously resolving hepatitis C virus (HCV) infection during the acute phase. We observed dysregulation of metabolic processes during early persistent infection that was linked to changes in expression of genes related to nucleosomal regulation of transcription, T cell differentiation, and the inflammatory response and correlated with subject age, sex, and the presence of HCV-specific CD4+ T cell populations. These early changes in HCV-specific CD8+ T cell transcription preceded the overt establishment of T cell exhaustion, making this signature a prime target in the search for the regulatory origins of T cell dysfunction in chronic viral infection

    Broadly directed virus-specific CD4+ T cell responses are primed during acute hepatitis C infection, but rapidly disappear from human blood with viral persistence

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    Vigorous proliferative CD4+ T cell responses are the hallmark of spontaneous clearance of acute hepatitis C virus (HCV) infection, whereas comparable responses are absent in chronically evolving infection. Here, we comprehensively characterized the breadth, specificity, and quality of the HCV-specific CD4+ T cell response in 31 patients with acute HCV infection and varying clinical outcomes. We analyzed in vitro T cell expansion in the presence of interleukin-2, and ex vivo staining with HCV peptide-loaded MHC class II tetramers. Surprisingly, broadly directed HCV-specific CD4+ T cell responses were universally detectable at early stages of infection, regardless of the clinical outcome. However, persistent viremia was associated with early proliferative defects of the HCV-specific CD4+ T cells, followed by rapid deletion of the HCV-specific response. Only early initiation of antiviral therapy was able to preserve CD4+ T cell responses in acute, chronically evolving infection. Our results challenge the paradigm that HCV persistence is the result of a failure to prime HCV-specific CD4+ T cells. Instead, broadly directed HCV-specific CD4+ T cell responses are usually generated, but rapid exhaustion and deletion of these cells occurs in the majority of patients. The data further suggest a short window of opportunity to prevent the loss of CD4+ T cell responses through antiviral therapy

    Detection of mixed populations of wild-type and YMDD hepatitis B variants by pyrosequencing in acutely and chronically infected patients

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    <p><b>Abstract</b></p> <p><b>Background</b></p> <p>Lamivudine (LAM) is associated with the highest known rate of resistance mutations among nucleotide analogs used to treat chronic hepatitis B virus (HBV) infection. Despite this, LAM continues in widespread use, especially in combination therapies. The primary LAM resistance mutation (rtM204V/I) occurs in the YMDD motif of HBV polymerase. The aim of this study was to characterize Brazilian HBV isolates from acute and chronic cases by direct sequencing, and to identify HBV quasispecies in the YMDD motif using a pyrosequencing method capable of detecting single-nucleotide polymorphisms. HBV DNA from serum samples of 20 individuals with acute HBV infection and 44 with chronic infection undergoing antiviral therapies containing LAM were analyzed by direct sequencing and pyrosequencing methods.</p> <p><b>Results</b></p> <p>Phylogenic analyses of direct-sequenced isolates showed the expected genotypes (A, D and F) for the Brazilian population in both acute and chronic infections. However, within genotype A isolates, subgenotype A2 was more frequently detected in acute cases than in chronic cases (P = 0.012). As expected, none of the individuals with acute hepatitis B had LAM-resistant isolates as a dominant virus population, whether detected by direct sequencing or pyrosequencing. However, pyrosequencing analyses showed that 45% of isolates (9/20) had minor subpopulations (4-17%) of LAM-resistant isolates. Among chronic patients undergoing LAM treatment, YMDD mutants were frequently found as a dominant virus population. In cases where wild-type virus was the dominant population, subpopulations of YMDD variants were usually found, demonstrating the complexity of HBV quasispecies.</p> <p><b>Conclusions</b></p> <p>YMDD variants were frequently detected as a minor population in acute HBV infection. The occurrence of pre-existing variants may lead to a high frequency of resistant mutants during antiviral therapy in the chronic phase. In chronic infection, detection of YMDD variants before virological or biochemical breakthrough might contribute to making better therapy choices and thus improving treatment outcome.</p
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