997 resultados para Hbv-dna


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The prevalence of occult hepatitis B virus (HBV) infection was investigated in 149 hepatitis B surface antigen (HBsAg) negative injecting drug users (IDUs) in the Central-West Region of Brazil. Of these individuals, 19 were positive for HBV DNA, resulting in an occult HBV infection prevalence of 12.7% (19/149); six of these 19 individuals had anti-HBV core and/or anti-HBV surface antibodies and 13 were negative for HBV markers. All IDUs with occult hepatitis B reported sexual and/or parenteral risk behaviours. All HBV DNA-positive samples were successfully genotyped. Genotype D was the most common (17/19), followed by genotype A (2/19). These findings reveal a high prevalence of occult HBV infection and the predominance of genotype D among IDUs in Brazil's Central-West Region.

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Despite the effectiveness of current hepatitis B virus (HBV) vaccines, it is estimated that 350 million individuals suffer from chronic HBV infection and more than 50% of these affected individuals live on the Asian continent. Panama is a country with a great diversity of foreign groups; the Chinese community is a large example of this phenomenon. There is an urgent need to perform studies that evaluate the prevalence and the genetic diversity of HBV in this community. This study aimed to evaluate the prevalence of HBV and its genotypes and mutant variants in the Chinese population residing in Panama. In total, 320 subjects were enrolled in the study. Forty-two subjects (13.1%) were positive for HBsAg and HBV-DNA from 18 subjects revealed the presence of genotypes B2 and C1. Secondary mutations associated with drug resistance at positions rtV207L and rtN239T of the reverse transcriptase gene were identified. Additionally, the mutation pair A1762T/G1764A was found in three samples and the mutation G1896A was detected in an HBeAg-negative subject. In conclusion, to our knowledge, this is the first study to report high HBV prevalence rates in resident ethnic Chinese in Central America and the presence of genotypes B2 and C1 in this region.

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In this cross-sectional study, 207 hepatitis B surface antigen (HBsAg)-negative kidney transplant recipients were evaluated based on demographic and epidemiological data and on the levels of serological markers of hepatitis B virus (HBV) and hepatitis C virus infection and liver enzymes. Patients with HBV or human immunodeficiency virus infection were excluded. Sera were analysed for the presence of HBV-DNA. HBV-DNA was detected in two patients (1%), indicating occult hepatitis B (OHB) infection (the HBV-DNA loads were 3.1 and 3.5 IU/mL in these patients). The results of the liver function tests were normal and no serological markers indicative of HBV infection were detected. The prevalence of OHB infection was low among kidney transplant recipients, most likely due to the low HBsAg endemicity in the general population of the study area.

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Studies on the prevalence of infection with hepatitis B virus (HBV) among children are scarce in Latin American countries, especially in Mexico. This study was aimed to investigate the prevalence of HBV infection, occult hepatitis B infection (OBI) and HBV genotypes among children with clinical hepatitis. In total, 215 children with clinical hepatitis were evaluated for HBV infection. HBV serological markers and HBV DNA were analysed. OBI diagnosis and HBV genotyping was performed. HBV infection was found in 11.2% of children with clinical hepatitis. Among these HBV DNA positive-infected children, OBI was identified in 87.5% (n = 21/24) of the cases and 12.5% (n = 3/24) were positive for both HBV DNA and hepatitis B surface antigen. OBI was more frequent among children who had not been vaccinated against hepatitis B (p < 0.05) than in those who had been vaccinated. HBV genotype H was prevalent in 71% of the children followed by genotype G (8%) and genotype A (4%). In conclusion, OBI is common among Mexican children with clinical hepatitis and is associated with HBV genotype H. The results show the importance of the molecular diagnosis of HBV infection in Mexican paediatric patients with clinical hepatitis and emphasise the necessity of reinforcing hepatitis B vaccination in children.

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Background: Reduction of necroinflammatory activity is a major goal of antiviral therapy of patients with chronic hepatitis B. Serum ALT does not detect all forms of cell death.Objectives: To analyze dynamics of novel serum cell death markers for apoptosis and necrosis in association with virologic response to nucleos(t)ide (Nuc) analogue treatment.Study design: Quantification of the M30-apoptosis neoepitope and the cytokeratin-18 (M65-necrosis) serum levels before and during treatment of patients with chronic hepatitis B with Nuc (n = 26).Results: Before treatment, M30-apoptotic activity was significantly correlated with M65-necrosis and fibrosis but not with serum ALT. During therapy with Nucs, cell death parameters M30-apoptosis, M65-necrosis, and ALT declined in association with virologic response. The most frequent cell death pattern was simultaneous decline of ALT and M30-apoptosis which occurred more frequently in patients with HBs-Antigen decline than in patients with HBs-Antigen increase during treatment (87.5% vs. 40.0%; p = 0.024). ALT decline in association with increase of M30 apoptosis was frequent in patients with HBs-Antigen increase during treatment (36.3%) but was not observed in patients with HBs-Antigen decline during treatment.Conclusion: Decline of cell death parameters in association with decline of HBV-DNA and HBs-Antigen indicates a reduction in overall cell death activity during Nuc treatment supporting the concept that response to Nuc therapy reduces necroinflammatory activity and progression of liver disease. (C) 2011 Elsevier B. V. All rights reserved.

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L'hépatite D chronique est la forme la moins fréquente, mais la plus sévère des hépatites virales chroniques. L'hépatite D ne s'observe qu'en combinaison avec une infection par le virus de l'hépatite B (HBV). Chaque patient dont l'antigène HBsAg est positif doit être mis au bénéfice d'un dépistage sérologique à la recherche d'une co-infection par le virus de l'hépatite D (HDV). Une hépatite D chronique doit être plus particulièrement recherchée dans les situations suivantes: hépatite active avec HBsAg positif et HBV DNA faible ou indétectable, exacerbation d'une hépatite B chronique avec anticorps IgM anti-HBc négatif, hépatite B aiguë sévère ou fulminante. Le traitement actuel consiste en l'administration d'interféron-a pégylé. Ce traitement n'est cependant curatif que chez 20% des patients environ. Une transplantation hépatique doit être envisagée chez les patients ayant une cirrhose avancée ou un carcinome hépatocellulaire d'extension limitée. Les mesures préventives contre l'hépatite D sont les mêmes que celles contre l'hépatite B.

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Antiviral therapies are associated with an increased risk of acute rejection in transplant patients. The aim of the present study was to evaluate the efficacy and safety of lamivudine therapy for hepatitis B virus (HBV) infection in renal transplant patients. Six patients were included in this study. They received 150 mg/day of lamivudine during a follow-up period of 24 months. The laboratory tests monitored were HBV DNA, HBsAg, HBeAg, ALT, gamma-GT, serum creatinine and blood cyclosporine levels. The HBV DNA became undetectable in four patients as early as in the third month of treatment. After six months, the viral load was also negative in the other two patients, and remained so until 18 months of follow-up. The medication was well tolerated with no major side effects. Lamivudine was safe and effective in blocking HBV replication in renal transplant patients without any apparent increase in the risk of graft failure for the 24-month period of study.

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Few data are available in the literature concerning the efficacy of standard hysteroscope disinfection procedures to prevent hepatitis B transmission. The aim of the present study was to determine the risk of hepatitis B virus (HBV) transmission during hysteroscopy among anti-HBc-seropositive women. Serum and hysteroscopic samples were collected from 62 women after diagnostic hysteroscopy. All samples were tested for serologic HBV markers. Polymerase chain reactions (PCR) were carried out to amplify regions C and S of the viral genome and only samples amplified by both pairs of primers were considered to be positive. Anti-HBc was repeatedly reactive in 48 (77%) of 62 serum samples, and HBsAg was detected in 8 (13%). At least one HBV serologic marker was found in 49 (79%) samples. Only one sample was HBsAg positive and anti-HBc negative. HBV-DNA was detected by PCR in 7 serum samples but in only 3 hysteroscopic samples obtained just after hysteroscopy. It is noteworthy that high levels of anti-HBc IgM were detected in one HBsAg-negative patient who showed an HBV-DNA-positive hysteroscopic sample. An elevated sample/cut-off ratio for anti-HBc IgM suggests recent infection and reinforces the need for testing for HBsAg and anti-HBc before hysteroscopy, since acute hepatitis B can be clinically asymptomatic. Viral DNA was not detected in any hysteroscopic samples collected after washing and disinfecting procedures with glutaraldehyde. We conclude that HBV-DNA can be found in the hysteroscope soon after hysteroscopy, but standard disinfecting procedures are effective in viral removal.

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Given the loss of therapeutic efficacy associated with the development of resistance to lamivudine (LMV) and the availability of new alternative treatments for chronic hepatitis B patients, early detection of viral genotypic resistance could allow the clinician to consider therapy modification before viral breakthrough and biochemical relapse occur. To this end, 28 LMV-treated patients (44 ± 12 years; 24 men), on their first therapy schedule, were monitored monthly at four Brazilian centers for the emergence of drug resistance using the reverse hybridization-based INNO-LiPA HBV DR assay and occasionally sequencing (two cases). Positive viral responses (HBV DNA clearance) after 6, 12, and 18 months of therapy were achieved by 57, 68, and 53% of patients, while biochemical responses (serum alanine aminotransferase normalization) were observed in 82, 82, and 53% of cases. All viral breakthrough cases (N = 8) were related to the emergence of YMDD variants observed in 7, 21, and 35% of patients at 6, 12, and 18 months, respectively. The emergence of these variants was not associated with viral genotype, HBeAg expression status, or pretreatment serum alanine aminotransferase levels. The detection of resistance-associated mutations was observed before the corresponding biochemical flare (41 ± 14 and 60 ± 15 weeks) in the same individuals. Then, if highly sensitive LMV drug resistance testing is carried out at frequent and regular intervals, the relatively long period (19 ± 2 weeks) between the emergence of viral resistance and the onset of biochemical relapse can provide clinicians with ample time to re-evaluate drug therapy.

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Occult hepatitis B virus (HBV) infection has been reported among patients with hepatitis C virus (HCV) infection and hepatocellular carcinoma (HCC). Our aim was to evaluate the presence of occult HBV infection in patients with HCV-related liver cirrhosis (LC) with or without HCC in São Paulo, Brazil. Serum and liver tissue samples from 50 hepatitis B surface antigen-negative patients with HCV-related LC who underwent liver transplantation at the University of São Paulo School of Medicine Hospital from 1993 to 2004 were divided into groups with LC only (N = 33) and with LC plus HCC (N = 17). HBV DNA was assayed for serum and paraffin-embedded liver tissue (tumoral and non-tumoral) using real time PCR and only 1 case with HCC had HBV DNA-positive serum. All liver samples were negative. HCV genotype 3 was detected in 17/39 (43.7%) cases. In conclusion, using a sensitive real time PCR directed to detect HBV variants circulating in Brazil, occult hepatitis B infection was not found among HCV-positive cirrhotic patients and was rarely found among HCV-positive HCC patients. These results are probably related to the low prevalence of HBV infection in our population. Furthermore, we have also shown that HCV genotype 3 is frequently found in Brazilian cirrhotic patients, particularly when they also have HCC. More studies involving a large number of cases should be carried out to confirm these data and to further characterize Brazilian HCV genotype isolates to elucidate genetic features that might be related to its carcinogenic potential.

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Estimates of occult hepatitis B virus (HBV) infection prevalence varies among different studies depending on the prevalence of HBV infection in the study population and on the sensitivity of the assay used to detect HBV DNA. We investigated the prevalence of occult HBV infection in cirrhotic patients undergoing liver transplantation in a Brazilian referral center. Frozen liver samples from 68 adults were analyzed using a nested polymerase chain reaction assay for HBV DNA. The specificity of the amplified HBV sequences was confirmed by direct sequencing of the amplicons. The patient population comprised 49 (72.1%) males and 19 (27.9%) females with a median age of 53 years (range=18-67 years). Occult HBV infection was diagnosed in three (4.4%) patients. The etiologies of the underlying chronic liver disease in these cases were alcohol abuse, HBV infection, and cryptogenic cirrhosis. Two of the patients with cryptic HBV infection also presented hepatocellular carcinoma. Markers of previous HBV infection were available in two patients with occult HBV infection and were negative in both. In conclusion, using a sensitive nested polymerase chain reaction assay to detect HBV DNA in frozen liver tissue, we found a low prevalence of occult HBV infection in cirrhotic patients undergoing liver transplant, probably due to the low prevalence of HBV infection in our population.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Com o objetivo de contribuir para um melhor conhecimento do eventual envolvimento das infecções pelos vírus das hepatites B e C, na etiopatogenia do carcinoma hapatocelular (CHC) na Amazônia Oriental, estudaram-se 36 pacientes internados em três hospitais públicos em Belém (PA), de janeiro de 1992 a março de 1999. Os critérios de inclusão adotados foram: o clínico, associado à imagenologia compatível, níveis séricos de alfafetoproteína (AFP) acima de 400ng/ml e/ou histopatologia compatível. Foram avaliados os aspectos clínicos, exames bioquímicos e hematológicos, imagenologia, histopatologia, níveis séricos de AFP e exames sorológicos das hepatites B e C. A presença dos ácidos nucléicos virais, o HBV-DNA e o HCV-RNA, foi avaliada a partir da detecção no soro pela reação em cadeia da polimerase. Observou-se um predomínio do sexo masculino (p<0.01), com reação M/F de 6,2: 1. Média e medianas gerais de idade foram, respectivamente, 50,8 e 53,0 anos, com amplitude de 6-81 anos. A maioria dos pacientes (52,7%) era procedente da zona rural, sendo a profissão de lavrador a mais freqüente (p<0,01). Etilismo foi encontrado em 33,3% dos casos. Dor abdominal e hepatomegalia, presentes em 94,4% dos casos, foram os sintomas e sinais mais freqüentes. Observou-se a presença de cirrose em 83,3% dos casos, sendo 80% enquadrados nas classes B e C (child-pugh). Cinqüenta por cento apresentaram complicações durante o diagnóstico, sendo as mais freqüentes a encefalopatia hepática e a hemorragia digestiva alta, relacionadas à doença hepática crônica de base. Marcadores sorológicos de infecção pelo HBV e pelo HCV foram encontrados em, respectivamente, 88,9% e 8,3% da casuística. Em 11,1% não se encontrou marcador sorológico. O HbsAg foi encontrado em 58, 3%. Anti-HBc foi encontrado em 86%, estando associado ao anti- HBs em 25%. Entre os HbsAg positivos: o anti- Hbe foi encontrado em 85%; o antiHBc IgM em 57,1%; e o anti-HD não foi detectado. O HBV- DNA foi encontrado em 37,7% do total de casos e em 65% dos HbsAG positivos. O HCV-RNA foi encontrado em 8,5% da amostra estudada e em 100% dos casos anti-HCV positivos. Não foi observada positividade para o HBV-DNA e para o HCV-RNA em soros de pacientes HbsAG ou anti- HCV negativos. A AFP esteve acima da normalidade em 88,9% dos casos, estando acima de 400 ng/ml em 75% e em 27,8% a titulações foi superior a 70.000 ng/ml. A ultrassonografia abdominal mostrou tumores com múltiplos nódulos em 63,9% e, nódulo único em 36,1% dos casos. O tipo histológico predominante foi carcinoma bem diferenciado do tipo trabecular (p<0,05). Os casos HbsAg positivos apresentaram menor média de idade e níveis de AFP mais elevados (p<0,01). A maioria dos pacientes se encontravam em fase avançada de doenças com uma taxa de óbito durante o diagnóstico de 38,9%. Conclui-se que, na Amazônia Oriental, a infecção pelo HBV parece exercer importância na etiologia do CHC, ressaltando-se a necessidade de incrementação de medidas preventivas, como vacinação e programa de detecção precoce do tumor em populações de risco. São necessários estudos adicionais controlados ou direcionados, para os possíveis co-fatores de importância na região, o que pode contribuir para um melhor entendimento dos mecanismos envolvidos na hepatocarcinogênese.

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Com o objetivo de contribuir para um melhor conhecimento do envolvimento das infecções pelos vírus das hepatites B e C, na etioepidemiologia do CHC na Amazônia Oriental, estudou-se 36 pacientes em Belém-PA. Foram avaliados marcadores sorológicos e a pesquisa do HBV-DNA e HCV-RNA pela reação em cadeia da polimerase. Observou-se etilismo em 33,3% e cirrose em 83,3%. Marcadores sorológicos das infecções pelo HBV e HCV foram encontrados respectivamente em 88,9% e 8,3%. O HBsAg foi encontrado em 58,3%; anti-HBc em 86%; anti-HBe em 85,7; HBeAg em 9,5%; anti-HBc IgM em 57,1%. O HBV-DNA foi detectado em 37,7% e em 65% dos HBsAg positivos; o HCV-RNA em 8,5% e em 100% dos anti-HCV positivos. AFP esteve alterada em 88,9% e acima de 400ng/ml em 75% dos casos. Conclui-se que a infecção pelo HBV parece ter importância na etiologia do CHC e ressalta-se a importância de implementar programas de vacinação e detecção precoce do tumor.

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A infecção pelo virus da hepatite B apresenta amplo espectro de manifestações clínicas. Objetivando conhecer os genótipos do HBV mais prevalentes e determinar a ocorrência da mutação pré-core A-1896, em uma população da Amazônia oriental, correlacionando com o diagnóstico clínico, foram selecionados 51 pacientes portadores crônicos de HBsAg e HBV-DNA positivos e divididos em três grupos: grupo A (n=14, pacientes assintomáticos); grupo B (n=20, sintomáticos HBeAg positivos) e grupo C (n=17, sintomáticos HBeAg negativos), sendo usado o sequenciador automático ABI modelo 377 para identificação de genótipos e mutantes pré-core. Os resultados evidenciaram o genótipo A como o mais prevalente, 81,8%, 89,5% e 93,7%, nos grupos A, B e C, respectivamente. A mutação pré-core A-1896 foi encontrada em 11,5% (3/26), sendo todos assintomáticos. Concluiu-se que na população estudada o genótipo A foi o mais prevalente e houve baixa ocorrência do mutante pré-core A-1896, ambos não se constituindo fatores agravantes da doença hepática.