RESUMO
Hepatitis B virus (HBV) is a major cause of chronic liver disease worldwide. HBV infection is diagnosed by serological tests, while real-time polymerase chain reaction (qRT-PCR) assays are used to quantify viral load, which is a crucial parameter to determine viral replication and to monitor antiviral treatments. However, measuring viral load in resource-limited countries remains nonsystematic, due to the high cost of commercial kits. Here, we describe the development, validation and implementation of a low-cost, in-house qRT-PCR assay to monitor HBV viral load in chronic carriers enrolled in the PROLIFICA programme in the Gambia and Senegal. Over 1500 HBsAg-positive patients, including 210 chronically infected HBV patients, who were given antiviral treatment (tenofovir), were monitored by qRT-PCR using the SYBR Green- and HBV-specific primers. Twenty-four tenofovir-treated patients were followed up and their viral load was tested every 3 months over the 12-month experimental time course. Compared to commercial assays, our in-house assay was shown to be (i) highly reliable, with good intra- and interassay reproducibility over a wide range (45-4.5 × 108 copies mL-1 ), (ii) very similar in the viral loads detected (R2 = .90), (iii) highly sensitive, as it detected loads as low as 30 copies mL-1 (~5 IU mL-1 ), (iv) cheaper (2- to 3-fold), (v) easier to implement and (vi) more rapid. Based on our experience, we recommend this assay as a reliable alternative to commercial assays, for monitoring HBV viraemia in resource-limited, highly endemic countries to reduce the cost and technical obstacles associated with commercial kits.
Assuntos
Vírus da Hepatite B/isolamento & purificação , Hepatite B Crônica/virologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Carga Viral/métodos , Antivirais , Benzotiazóis , Custos e Análise de Custo , Primers do DNA/genética , DNA Viral/análise , DNA Viral/genética , Diaminas , Monitoramento de Medicamentos/métodos , Seguimentos , Gâmbia , Hepatite B Crônica/tratamento farmacológico , Humanos , Compostos Orgânicos/metabolismo , Quinolinas , Reprodutibilidade dos Testes , Senegal , Sensibilidade e Especificidade , Coloração e Rotulagem/métodos , Tenofovir/administração & dosagem , Fatores de TempoRESUMO
Dysregulation of growth factors and their receptors is central to human hepatocellular carcinoma (HCC). We previously demonstrated that the Frizzled-7 membrane receptor mediating the Wnt signalling can activate the beta-catenin pathway and promotes malignancy in human hepatitis B virus-related HCCs. Expression patterns of all the 10 Frizzled receptors, and their extracellular soluble autoparacrine regulators (19 Wnt activators and 4 sFRP inhibitors) were assessed by real-time RT-PCR in 62 human HCC of different etiologies and their matched peritumorous areas. Immunostaining was performed to localise Frizzled on cell types in liver tissues. Regulation of three known Frizzled-dependent pathways (beta-catenin, protein kinase C, and C-Jun NH(2)-terminal kinase) was measured in tissues by western blot. We found that eight Frizzled-potentially activating events were pleiotropically dysregulated in 95% HCC and 68% peritumours as compared to normal livers (upregulations of Frizzled-3/6/7 and Wnt3/4/5a, or downregulation of sFRP1/5), accumulating gradually with severity of fibrosis in peritumours and loss of differentiation status in tumours. The hepatocytes supported the Wnt/Frizzled signalling since specifically overexpressing Frizzled receptors in liver tissues. Dysregulation of the eight Frizzled-potentially activating events was associated with differential activation of the three known Frizzled-dependent pathways. This study provides an extensive analysis of the Wnt/Frizzled receptor elements and reveals that the dysregulation may be one of the most common and earliest events described thus far during hepatocarcinogenesis.
Assuntos
Carcinoma Hepatocelular/genética , Receptores Frizzled/genética , Neoplasias Hepáticas/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Receptores Frizzled/biossíntese , Regulação da Expressão Gênica , Humanos , Neoplasias Hepáticas/patologiaRESUMO
HBV infection in the absence of HBsAg has been a matter of debate for years, but its existence and clinical relevance are now supported by many publications, editorials and reviews. HBV DNA without HBs antigenemia was detected in the following clinical situations: (1) Chronic, presumably viral, hepatitis unrelated to HCV, atypical alcoholic hepatitis and hepatocellular carcinoma (HCC); (2) viral reactivation following immunosuppression; (3) Transmission through transplantation, transfusion or experimental transmission to chimpanzees. Occult HBV infections are not restricted to areas of high HBV endemicity. Indeed, such cases have been described in Western countries including France. It is now established that occult HBV infection among non-HCV patients suffering from chronic hepatitis varies from 20% to 30% in Europe, and in the context of HCV infection it varies from 20% in France up to 80% in Japan. The percentage of occult HBV infections among non A-E cases depends on several parameters: (1) The method of detection, including PCR primer selection; (2) patient recruitment; (3) patients from countries highly endemic for HBV are more likely to develop occult HBV infections; (4) prevalence may also vary depending on the nature of biological material tested, with a higher proportion for liver compared to serum specimen. The mechanisms leading to HCC in occult HBV infection seem similar to those overt cases, patients with low-grade but diagnosable HBV replication that retains its pro-oncogenic properties. During the course of HCV infection, occult HBV infection may worsen liver damage induced by HCV and reduce the response to HCV antiviral treatment. Occult HBV infection is a frequent phenomenon and HBV DNA testing with highly sensitive PCR in the clinical setting is therefore becoming of paramount importance.
Assuntos
Carcinoma Hepatocelular/virologia , DNA Viral/análise , Antígenos de Superfície da Hepatite B/análise , Vírus da Hepatite B/isolamento & purificação , Hepatite B/virologia , Hepatite B/complicações , Hepatite B/diagnóstico , Hepatite B/imunologia , Vírus da Hepatite B/genética , Vírus da Hepatite B/fisiologiaRESUMO
BACKGROUND/AIM: Occult hepatitis B virus (HBV) infection is characterized by the presence of HBV DNA in the absence of hepatitis B surface antigen (HBsAg) in the patient serum. Although such infections have been identified in patients with chronic hepatitis C, the clinical significance of those co-infections is still not understood. Our aim was, therefore, to assess the prevalence and clinical consequences of occult HBV infection in chronic hepatitis C patients undergoing antiviral therapy. METHODS: The study population consisted of 53 HBsAg-negative patients with chronic hepatitis C treated with IFN/ribavirin or IFN/ribavirin/amantadine. Nine patients experienced a viral breakthrough (BT), 30 were non-responders (NR) and 14 were responders (R). HBV-DNA detection by PCR was performed using primers specific for the S region of the HBV genome and HCV-RNA detection by PCR with primers localised in both the 5'NC and core region of HCV genome, before, during and after treatment. Viral genome sequences were also studied. RESULTS: Occult HBV genomes were found in the serum of four of 53 (7.5%) patients, unrelated to anti-HBc status. No significant differences in biochemical, virological, or histological markers, age, duration of infection, were observed in patients with or without HBV DNA. There was an inverse correlation in the evolution of HBV DNA and HCV RNA levels. Direct sequencing showed that S gene of occult HBV presented mutations in the "a" determinant while no specific mutation in the core region of HCV was observed. None of the four patients co-infected with HBV and HCV were responders to anti-HCV therapy. CONCLUSION: In our clinical setting, the prevalence of occult HBV co-infection among patients with chronic hepatitis C was low and independent of the presence of markers of previous HBV infection. Further studies in larger cohort of patients are warranted to determine if occult HBV co-infection may be involved in HCV resistance to combination therapy.
Assuntos
Antivirais/uso terapêutico , Hepatite B Crônica/complicações , Hepatite B Crônica/tratamento farmacológico , Hepatite C Crônica/complicações , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Adulto , Amantadina/uso terapêutico , Sequência de Aminoácidos , DNA Viral/sangue , DNA Viral/química , Farmacorresistência Viral , Feminino , França , Hepacivirus/genética , Hepacivirus/isolamento & purificação , Vírus da Hepatite B/genética , Vírus da Hepatite B/isolamento & purificação , Humanos , Interferon alfa-2 , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Viral/sangue , RNA Viral/química , Proteínas Recombinantes , Ribavirina/uso terapêutico , Alinhamento de Sequência , Análise de Sequência de DNA , Carga ViralRESUMO
Social phobia is one of the most frequent mental disorders and is accessible to two forms of scientifically validated treatments: anti-depressant drugs and cognitive behavior therapies (CBT). In this last case, graded exposure to feared social situations is one of the fundamental therapeutic ingredients. Virtual reality technologies are an interesting alternative to the standard exposure in social phobia, especially since studies have shown its usefulness for the fear of public speaking. This paper reports a preliminary study in which a virtual reality therapy (VRT), based on exposure to virtual environments, was used to treat social phobia. The sample consisted of 36 participants diagnosed with social phobia assigned to either VRT or a group-CBT (control condition). The virtual environments used in the treatment recreate four situations dealing with social anxiety: performance, intimacy, scrutiny, and assertiveness. With the help of the therapist, the patient learns adapted cognitions and behaviors in order to reduce anxiety in the corresponding real situations. Both treatments lasted 12 weeks, and sessions were delivered according to a treatment manual. Results showed statistically and clinically significant improvement in both conditions. The effect-sizes comparing the efficacy of VRT to the control traditional group-CBT revealed that the differences between the two treatments are trivial.
Assuntos
Terapia Cognitivo-Comportamental/métodos , Internet/instrumentação , Transtornos Fóbicos/terapia , Interface Usuário-Computador , Adaptação Psicológica , Adulto , Assertividade , Medo , Feminino , Humanos , MasculinoRESUMO
Despite a number of studies documenting hepatitis B virus (HBV) infection in the absence of hepatitis B surface antigen (HBsAg) a causal relationship between silent HBV infection and liver disease remain difficult to establish. In particular, both the prevalence and clinical significance of this observation are poorly understood. Why is HBV replication apparently so low in these patients? A number of studies have tried to elucidate the mechanism of HBsAg negative infections, and considerable data documenting HBV infectivity or reinfection in the absence of detectable HBsAg support the hypothesis that in some of these cases, HBV is undergoing low-level replication in the liver and this, in several situations including: (1) chronic liver disease, alcoholic liver disease, hepatocellular carcinoma; (2) viral reactivation following cancer chemotherapy or immunosuppression and (3) transmission via transfusion or from human serum to chimpanzees. In a recent study including 50 patients with chronic liver disease of unknown etiology we could detect serum HBV DNA by nested polymerase chain reaction (PCR) in 15/50 patients (50% at the cirrhosis stage) in the absence of HBsAg; in the liver of the 15 patients both HBcAg and/or HBsAg can be detected at very low-level. Viral host factors allowing HBV persistence in the absence of HBsAg can depend on several mechanisms. Coinfections with HCV can explain only a proportion of HBsAg(-) HBV infections. Secondly, HBV mutations in the core promotor region leading to a minimal viral replication, or mutations in the HBsAg-encoding region might explain the absence of serological recognition. Finally, it is possible that in some cases host immune mechanisms can maintain HBV infection in a latent state until transmission to another individual who subsequently develops a more active infection especially when immunosuppressive therapy is employed. Existence of HBsAg(-) HBV infections should be taken into account by the use of sensitive PCR tests for prevention of viral transmission in the settings of blood donations and organ transplants.
Assuntos
Antígenos de Superfície da Hepatite B/análise , Vírus da Hepatite B/fisiologia , Hepatite B/virologia , Carcinoma Hepatocelular , DNA Viral/análise , Hepatite B/diagnóstico , Hepatite B/imunologia , Vírus da Hepatite B/imunologia , HumanosRESUMO
The diagnostic value of preS antigens and anti-preS antibodies during Hepatitis B virus (HBV) infections have not yet been clearly elucidated. Therefore, the objectives of this study were: 1) to better understand the clinical significance of the expression of both preS1 and preS2 antigens (preS1Ag and preS2Ag) in the serum of chronic HBsAg carriers, and 2) to define the respective role of antibody responses to HBs-, preS2- and preS1-specific determinants in the course of acute hepatitis B (AH-B) infections with different outcomes. Our data showed that the serum preS1Ag/HBsAg ratio correlated well with the level of viral replication (serum HBV-DNA as monitored by PCR assay and liver HBcAg), especially in anti-HBe positive chronic carriers. The complete eradication of virions required a persistent antibody response to conformation-dependent HBs-epitopes, temporally associated with a vigorous T cell response to nucleocapsid antigens. Recovery from hepatitis B can be achieved when there is no early antibody response to preS2- and preS1-proteins, which was found to be transient, concomitant with a flare-up of the liver disease, and preceding anti-HBs production. Information on the patterns of preS antigens and their antibodies remained clouded because of the varying specificities and sensitivities of research methods used in studies to date. We have, therefore, developed original Polyclonal-Monoclonal RadioImmunoAssays (PAb-MAb RIAs) by using monoclonal antibodies (MAbs) having previously well-defined specificities. We could thus detect and quantify simultaneously the three distinct antigenicities of the HBV envelope, HBsAg, preS2Ag and preS1Ag, with the same sensitivity. In this way, the preS1Ag/HBsAg and preS2Ag/HBsAg ratios can be calculated to estimate the serum expression of both preS1Ag and preS2Ag in relation to total HBsAg activity during different stages of chronic HBV infection. For optimal management of the state of HBV replication in chronic viral infection, the detection of HBV-DNA in serum was monitored by the Polymerase Chain Reaction (PCR) assay. We extended our work by investigating the clinical significance of antibody response to preS-specific determinants in patients with AH-B showing different outcomes in both natural course or response to alpha-interferon therapy. In a first attempt, we chose to use the Western Immuno-Blotting Assay (WIBA) to obtain a qualitative assessment of the nature of preS antibody responses. Finally, the cell-mediated immune response to HBV antigens was also studied in several patients with self-limited AH-B leading to a relevant finding which may help to clarify the mechanisms responsible for complete clearance of HBV.
Assuntos
Anticorpos Anti-Hepatite B/sangue , Antígenos de Superfície da Hepatite B/biossíntese , Antígenos de Superfície da Hepatite B/genética , Hepatite B/imunologia , Hepatite Crônica/imunologia , Precursores de Proteínas/genética , Doença Aguda , Formação de Anticorpos , DNA Viral/sangue , Hepatite B/tratamento farmacológico , Anticorpos Anti-Hepatite B/metabolismo , Antígenos do Núcleo do Vírus da Hepatite B/análise , Antígenos de Superfície da Hepatite B/imunologia , Hepatite Crônica/tratamento farmacológico , Humanos , Interferons/uso terapêutico , Fígado/imunologia , Fígado/patologia , Taxa de Depuração Metabólica , Reação em Cadeia da Polimerase , Estudos Prospectivos , Linfócitos T/imunologia , Proteínas do Envelope Viral/genéticaRESUMO
Gene amplification may benefit from the construction of primers that augments the speed at which cloning and protein expression proceeds. Such primers include EcoRI or HindIII linkers as well as an in phase initiation or termination codon. PCR was carried out directly from viral particles of human hepatitis B virus (HBV) and woodchuck hepatitis virus (WHV) without DNA purification and from RNA extracted from WHV infected liver. Amplified products were directly cloned in the pKK223-3 expression vector under the control of the tac promoter. The characterization of the recombinant clones expressing the nucleocapsid protein (C protein) was done by direct incubation of the filter with 125I-labelled anti-HBc and confirmed by radioimmunoassay and Western-blot analysis. This procedure allows easy selection of recombinant clones expressing a given protein and could be applied to many other genes.
Assuntos
Capsídeo/biossíntese , Capsídeo/genética , DNA Viral/genética , Vírus de Hepatite/genética , RNA Viral/genética , Proteínas do Core Viral/biossíntese , Proteínas do Core Viral/genética , Animais , Sequência de Bases , Clonagem Molecular , Vírus da Hepatite B/genética , Marmota , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Proteínas Recombinantes/biossínteseRESUMO
The peripheral blood mononuclear cells (PBMC) of woodchucks experimentally infected by woodchuck hepatitis virus (WHV) were examined simultaneously for the presence of membrane associated WHV antigens by cytofluorometry, and for WHV DNA and RNA sequences by the polymerase chain reaction (PCR). Four woodchucks were inoculated: two with a well-defined infectious inoculum and two with an inoculum obtained from an animal at the late incubation phase, which was positive for WHV DNA by PCR but still devoid of WHV markers. Infection was demonstrated in all four inoculated woodchucks by the appearance at different times of WHV DNA and WHV antigens in both leucocytes and serum. WHV DNA was first detected by PCR either in the serum (two cases) or in leucocytes (two cases). The mean percentage of cells positive for membrane associated WHsAg or WHcAg detected by cytofluorometry were 37% +/- 25 and 17% +/- 15 respectively. After 8 weeks, all inoculated animals were WHsAg positive in serum. These data suggest that PBMC are involved in the early events of hepadnavirus infection. They also show that sera which are positive by PCR for WHV DNA may transmit viral infection even while still seronegative for WHV markers and for WHV DNA by dot blot.
Assuntos
Vírus da Hepatite B da Marmota/isolamento & purificação , Hepatite B/microbiologia , Leucócitos Mononucleares/microbiologia , Animais , Anticorpos Antivirais/imunologia , Antígenos Virais/biossíntese , Antígenos Virais/sangue , Antígenos Virais/imunologia , Biomarcadores/sangue , DNA Viral/biossíntese , DNA Viral/sangue , Citometria de Fluxo , Vírus da Hepatite B da Marmota/crescimento & desenvolvimento , Vírus da Hepatite B da Marmota/imunologia , Leucócitos Mononucleares/imunologia , Marmota/microbiologia , Reação em Cadeia da Polimerase , RNA Viral/biossíntese , RNA Viral/sangue , Radioimunoensaio , ViremiaRESUMO
Social phobia is an anxiety disorder that is accessible to two forms of treatment yielding scientifically validated results: drugs and cognitive-behavioral therapies. Graded exposure to feared social situations is fundamental to obtain an improvement of the anxious symptoms. Traditionally, exposure therapies are done either in vivo or by imagining the situations. In vivo exposure is sometimes difficult to control and many patients have some difficulties in using imagination. Virtual reality (VR) seems to bring significant advantages. It allows exposures to numerous and varied situations. This paper reports the definition of a clinical protocol whose purpose is to assess the efficiency of a VR therapy compared to a CBT and to the absence of treatment for social phobic patients. It explains the illness' diagnosis and its usual treatments. It exposes all the architecture of the study, the assessment tools, the content and unfold of the therapy sessions. It finally reports first results of a clinical trial in a between-group design in 10 patients suffering from social phobia. The virtual environments used in the treatment reproduce four situations that social phobics feel the most threatening: performance, intimacy, scrutiny and assertiveness. With the help of the therapist, the patient learns adapted cognitions and behaviors with the aim of reducing her or his anxiety in the corresponding real situations. The novelty of our work is to address a group of situations that the phobic patient is most likely to experience and to treat patients according to a precise protocol.
Assuntos
Terapia Comportamental/instrumentação , Terapia Comportamental/métodos , Simulação por Computador , Transtornos Fóbicos/terapia , Terapia Assistida por Computador/instrumentação , Interface Usuário-Computador , Adulto , Protocolos Clínicos , Feminino , Humanos , Masculino , Projetos Piloto , Psicometria , Software , Terapia Assistida por Computador/métodosRESUMO
BACKGROUND: The potential reservoir role of serum and peripheral blood mononuclear cells (PBMCs) for total HBV DNA (tDNA) and cccDNA still remains unknown. MATERIAL AND METHODS: We analyzed tDNA and cccDNA with a single sensitive and validated standardized real-time PCR method in serum and PBMCs in two populations of chronic HBV infection coinfected or not with HCV and/or HIV viruses: a retrospective cohort of 130 HBsAg-negative (HBsAg-) patients with "anti-HBc alone" or anti-HBc and anti-HBs antibodies (Ab) and a cohort of 70 HBsAg-positive patients, 16 of them being prospectively followed under treatment. RESULTS: Among HBsAg- patients, HBV DNA was detected in serum or PBMCs in about half of the cases with various distributions of tDNA and cccDNA: in HIV-negative patients with an "antiHBc alone" profile, tDNA was mostly detected in PBMCs suggesting a possible active role of PBMCs; although cccDNA was not detected in PBMCs in HIV-positive patients, tDNA and cccDNA were mostly observed in serum, suggesting a specific pattern of more "persistent" than "occult" infection in this population. Patients with anti-HBc and anti-HBs Ab harbored tDNA in serum or in PBMCs, regardless of their HIV or HCV status, raising the question of a viral reactivation risk during immunosupression in these patients. Among HBsAg+ patients, tDNA was detected in serum and PBMCs of 88.5% of the cases and cccDNA in 22%. Levels of tDNA in both compartments were highly correlated during treatment, suggesting a passive reservoir role for PBMCs. CONCLUSION: The respective distribution of tDNA and cccDNA in serum and PBMCs may reflect the different immune statuses of the host in HBsAg+ and HBsAg- patients. The frequency of HBV DNA in PBMCs from AgHBs- patients suggests a viral reactivation risk during immunodepression in those patients.
Assuntos
DNA Circular/sangue , DNA Viral/sangue , Infecções por HIV/sangue , Infecções por HIV/imunologia , Antígenos de Superfície da Hepatite B/sangue , Vírus da Hepatite B/genética , Hepatite B/sangue , Hepatite B/imunologia , Leucócitos Mononucleares , Coinfecção , Infecções por HIV/complicações , Hepatite B/complicações , Humanos , Estudos RetrospectivosRESUMO
Alzheimer disease (AD) and other related dementia represent a major challenge for health care systems within the aging population. It is therefore important to develop better instruments for assessing disease severity and disease progression to optimize patient's care and support to care providers, and also provide better tools for clinical research. In this area, Information and Communication Technologies (ICT) are of particular interest. Such techniques enable accurate and standardized assessments of patients' performance and actions in real time and real life situations. The aim of this article is to provide basic recommendation concerning the development and the use of ICT for Alzheimer's disease and related disorders. During he ICT and Mental Health workshop (CTAD meeting held in Monaco on the 30th October 2012) an expert panel was set up to prepare the first recommendations for the use of ICT in dementia research. The expert panel included geriatrician, epidemiologist, neurologist, psychiatrist, psychologist, ICT engineers, representatives from the industry and patient association. The recommendations are divided into three sections corresponding to 1/ the clinical targets of interest for the use of ICT, 2/ the conditions, the type of sensors and the outputs (scores) that could be used and obtained, 3/ finally the last section concerns specifically the use of ICT within clinical trials.
Assuntos
Doença de Alzheimer , Avaliação Geriátrica/métodos , Guias como Assunto , Monitorização Fisiológica/métodos , Projetos de Pesquisa , Análise e Desempenho de Tarefas , Tecnologia , Atividades Cotidianas/psicologia , Idoso , Doença de Alzheimer/psicologia , Ensaios Clínicos como Assunto , Comunicação , Congressos como Assunto , Demência , Progressão da Doença , Humanos , Mônaco , Psicometria , Índice de Gravidade de DoençaRESUMO
A number of risk factors appear to play a role in Hepatocellularcinoma (HCC), HBV infection being one of the most important. Chronic inflammation and cytokines are key determinants in the development of fibrosis and liver cell proliferation. HBV DNA integration and/or expression of HBV proteins may have a direct effect on cellular functions. Occult hepatitis B virus infection is characterized by persistence of HBV DNA in hepatitis B surface antigen-negative individuals. There are evidences that occult HBV is a risk factor for the development of HCC and that the potential mechanisms whereby overt HBV might induce tumour formation are mostly maintained.
Assuntos
Carcinoma Hepatocelular/virologia , Vírus da Hepatite B/isolamento & purificação , Neoplasias Hepáticas/virologia , DNA Viral/genética , DNA Viral/isolamento & purificação , Vírus da Hepatite B/genética , Vírus da Hepatite B/fisiologia , Hepatite B Crônica/patologia , Hepatócitos/patologia , Humanos , Replicação ViralRESUMO
Occult hepatitis B virus (HBV) infection is common in chronic hepatitis C patient. However, its significance and consequences are still unclear. The aim of this study was to evaluate the prevalence of occult HBV among HCV chronic carriers in France and to assess its impact on liver histology and response to antiviral therapy. To this end a cohort of 203 patients with chronic hepatitis C without hepatitis B surface antigen (HBsAg) has been examined. Serum HBV-DNA was detected using a highly sensitive PCR with primers located in the S and X genes. HBV viraemia levels were further determined by real-time PCR. Results showed that 47 of 203 (23%) patients had occult HBV infection with a low HBV load (10(2)-10(4) copies/ml) but significantly higher HCV-RNA titers (P < 0.05). No significant difference in age, gender, serum ALT level, HCV genotypes, and the presence of anti-HBc was observed between patients with or without HBV-DNA. When compared histologically, patients with occult HBV infection had higher activity (A2-A3 in 53% vs. 38%, P < 0.01) and more advanced fibrosis (60% vs. 33%, P < 0.001) than HBV-DNA negative cases. Sustained response to combination therapy against Chronic hepatitis C was achieved in 11 (28%) of 40 HBV-DNA positive cases, compared with 65 (45%) of the 144 HBV-DNA negative cases (P < 0.05). Among the 144 HBV-DNA negative HCV patients those with genotype 1 responded less frequently to therapy as compared to other genotypes infected patients (38% vs. 55%, P < 0.05). Surprisingly, when considering all patients studied, irrespective to the HBV-DNA status no significant difference was observed in response to combination therapy regarding HCV genotypes (39% vs. 44%, P > 0.05). In conclusion, HBV-DNA is found in 1/4 of French chronic hepatitis C patients regardless of the presence of anti-HBc. Such an occult HBV co-infection is associated with more severe liver disease, higher HCV viral load and decreased response to antiviral therapy irrespective of HCV genotypes.
Assuntos
Hepatite B/diagnóstico , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Ribavirina/uso terapêutico , Adulto , Idoso , Antivirais/uso terapêutico , Quimioterapia Combinada , Feminino , Humanos , Interferon alfa-2 , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes , Fatores de Risco , Falha de Tratamento , Carga ViralRESUMO
Reported here is a case of double hepatitis B virus (HBV) infection in an HIV/hepatitis C virus (HCV)-coinfected patient with antibodies against hepatitis B core antigen as the only serological marker (anti-HBc alone). Two different HBV genotypes were identified in this patient. A search of the medical literature indicated this report is the first to describe a multiple silent HBV infection in an HIV/HCV-coinfected-patient. The elevated incidence of the anti-HBc alone pattern in HIV-positive patients and the increasing number of silent HBV infections detected in those patients demonstrate the need to carefully examine HIV-positive patients for occult HBV infection. In addition, it appears necessary to thoroughly study such patients in order to evaluate the impact of mixed HBV infection and triple HIV/HCV/HBV infection on morbidity.
Assuntos
Infecções por HIV/complicações , Hepatite B/complicações , Hepatite C/complicações , DNA Viral/sangue , DNA Viral/genética , Genótipo , Hepatite B/imunologia , Hepatite B/virologia , Anticorpos Anti-Hepatite B/sangue , Antígenos do Núcleo do Vírus da Hepatite B/isolamento & purificação , Vírus da Hepatite B/genética , Vírus da Hepatite B/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Polymerase chain reaction (PCR) with a reverse transcriptase step characterized a specific transcription activity in hepatitis B virus (HBV)-infected peripheral blood mononuclear cells (PBMC) in two patients (1 and 2) with chronic hepatitis positive for antibody to hepatitis B core antigen (HBc). Patient 1 was also coinfected with human hepatitis delta virus. A patient who cleared HBV replication after antiviral treatment with vidarabine served as negative control. HBV-specific RNA poly A sequences were detected by PCR in PBMC of patients 1 and 2 even without detectable HBV DNA (patient 2) as shown by dot blot and PCR assays. RNA sequences were found in both the nucleus and cytoplasm. The demonstration of HBV mRNA sequences within PBMC suggests the transcription of viral DNA, in agreement with the findings of HBV surface antigen in PBMC. The results in patient 1 demonstrated HBV mRNA sequences in leukocytes even without PCR-detectable HBV DNA sequences, likely due to ongoing hepatitis delta virus replication.
Assuntos
Vírus da Hepatite B/genética , Hepatite B/microbiologia , Leucócitos Mononucleares/microbiologia , Poli A/sangue , RNA Viral/sangue , RNA/sangue , Sequência de Bases , Southern Blotting , Portador Sadio/microbiologia , DNA Viral/sangue , DNA Viral/química , Hepatite B/complicações , Hepatite D/complicações , Hepatite Crônica/microbiologia , Humanos , Fígado/microbiologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Mensageiro , Replicação ViralRESUMO
OBJECTIVE: To review the literature on the TT virus. METHODS: The literature review was based on articles identified through MEDLINE between Jan. 1, 1997, and August 15, 1999. RESULTS: In 1997, a new DNA virus, designated TTV, was isolated and seemed to be associated with non A-G post-transfusion hepatitis. The virus was identified using a polymerase chain reaction (PCR) because serology was not routinely available. At least 16 genotypes were identified. Depending on the PCR technique used, the prevalence of infection ranged from 17% to 71% in a group of sera tested. The prevalence rate ranged from 1.2% to 62% among blood donors, from 0.5% to 83% among hemophiliacs and from 1% to 71% in cases of chronic hepatitis. The current hypothesis is that routes of infection were parenteral and orofecal. The pathogenesis of this virus, if it really exists, is not yet clearly established. It has been postulated that some interaction may exist between the TT virus and the hepatitis C virus. The use of interferon seems to decrease the TT viremia, according to results obtained outside the context of clinical trials. CONCLUSION: The pathogenesis of the TT virus needs to be rapidly established for transmission prevention and therapeutic intervention.
Assuntos
Torque teno virus , Infecções por Vírus de DNA/epidemiologia , Infecções por Vírus de DNA/prevenção & controle , Infecções por Vírus de DNA/transmissão , DNA Viral/análise , Genótipo , Hepatite Viral Humana/transmissão , Humanos , MEDLINE , Reação em Cadeia da Polimerase , Torque teno virus/genética , Torque teno virus/patogenicidade , Torque teno virus/fisiologia , Reação Transfusional , ViremiaRESUMO
By the use of reverse transcription followed by polymerase chain reaction (RT-PCR), we have identified one shorter than full-length, pregenomic viral RNA species in liver samples of woodchucks chronically infected with the woodchuck hepatitis virus (WHV). The spliced WHV RNA of about 2.4 kb in length was cloned and partially sequenced. The splicing donor and acceptor sites of this novel RNA are located, respectively, 130 nucleotides downstream of the ATG initiation codon of the core gene and 21 nucleotides upstream of the initiation codon of the pre-S2 surface gene. The splicing event generates a new core-polymerase fusion protein and removes the terminal protein domain and the spacer region of the polymerase gene. A nucleotide probe specific for the splice junction was used following RT-PCR, to further confirm the existence of this spliced RNA in the liver of seven WHV-infected woodchucks. Deleted viral DNA molecules corresponding to the 2.4 kb spliced RNA were also detected in the liver and, to a lesser extent, in the serum of infected woodchucks, suggesting that this spliced RNA can be encapsidated and reverse-transcribed during the course of natural WHV infection.
Assuntos
Hepadnaviridae/genética , Hepatite Viral Animal/microbiologia , Splicing de RNA , RNA Viral/metabolismo , Transcrição Gênica , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Southern Blotting , Clonagem Molecular , DNA Viral , Hepadnaviridae/fisiologia , Marmota , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Viral/genética , DNA Polimerase Dirigida por RNA/metabolismoRESUMO
AIMS/BACKGROUND: The objective of this work was to evaluate the possible modulation of carcinogen metabolizing enzymes in relation to chronic infection by hepatitis B virus (HBV). This was to test whether enzyme level is altered in association with HBV gene expression per se or only when that expression was associated with an induction of liver injury. METHODS: For this purpose, we studied four different HBV transgenic mouse lineages (23.3, 45.2, 50.4 and 107.5) that express the transgene encoding for the large envelope protein (HBsAg) at different levels. These lineages exhibit an associated liver injury which progresses with age and is positively correlated with the degree of accumulation of HBsAg in the hepatocytes. The modulation of levels of cytochrome P450 (1a, 2a-5, 2b, 2c, 3A4 and 2E1) and glutathione S-transferases (GST alpha and pi) involved in carcinogen metabolism was examined by immunohistochemistry in these lineages. RESULTS: While we observed an increase in staining intensity of P450s 1-a and 2a-5 in lineages expressing cytopathic amounts of HBsAg (lineages 50.4 and 45.2), we only observed minor changes or no changes at all for the other lineages (23.3 and 107.5). Staining with antibodies to cytosolic pi class GST demonstrated an increase in older mice, although no major alterations were observed for GST alpha. CONCLUSIONS: These results suggest that liver cell injury induced by accumulation of HBV antigens can result in the induction of some carcinogen metabolizing enzymes and this may be one mechanism of chemical-viral interaction in hepatocarcinogenesis.
Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Glutationa Transferase/metabolismo , Antígenos de Superfície da Hepatite B/biossíntese , Vírus da Hepatite B/metabolismo , Hepatite B/enzimologia , Fígado/patologia , Animais , Carcinógenos/metabolismo , Expressão Gênica , Hepatite B/metabolismo , Hepatite B/patologia , Hepatite B/virologia , Vírus da Hepatite B/genética , Camundongos , Camundongos TransgênicosRESUMO
The relative roles of hepatitis B virus (HBV) and aflatoxin and their possible mechanism of interaction in the etiopathogenesis of hepatocellular carcinoma (HCC) are not understood. One hypothesis is that viral infection and associated liver injury alter expression of carcinogen-metabolizing enzymes. We tested this hypothesis in an HBV-transgenic mouse model in which a synergistic interaction occurs between aflatoxin B1 (AFB1) and HBV in the induction of HCC (Sell et al., Cancer Res 51:1278-1285, 1991). In this transgenic mouse lineage, overproduction of the HBV large envelope protein results in progressive liver cell injury, inflammation, and regenerative hyperplasia. Initially, two cytochrome P450s of importance in AFB1 metabolism in the mice were identified, namely Cyp2a-5 and Cyp3a, using specific antibodies and chemical inhibitors. The expression of these P450 isoenzymes and an alpha-class glutathione S-transferase (GST) isoenzyme, YaYa, were examined. Increased expression and altered distribution of Cyp2a-5 were demonstrated, by immunohistochemical analysis, to be associated with the development of liver injury in mice and to increase with age between 1 and 12 months. Cyp3a expression was also increased in HBV-transgenic mice, but the increase was not as clearly related to age. GST YaYa levels were the same in HBV-transgenic mice and their nontransgenic littermates of all ages. These results show that expression of specific cytochrome P450s is altered in association with overexpression of HBV large envelope protein and liver injury in this model. This may have general relevance to human HCC, the etiology of which is associated with a diverse range of liver-damaging agents.