935 resultados para ANTI-HEPATITIS C VIRUS


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The strategy used to treat HCV infection depends on the genotype involved. An accurate and reliable genotyping method is therefore of paramount importance. We describe here, for the first time, the use of a liquid microarray for HCV genotyping. This liquid microarray is based on the 5'UTR - the most highly conserved region of HCV - and the variable region NS5B sequence. The simultaneous genotyping of two regions can be used to confirm findings and should detect inter-genotypic recombination. Plasma samples from 78 patients infected with viruses with genotypes and subtypes determined in the Versant (TM) HCV Genotype Assay LiPA (version I; Siemens Medical Solutions, Diagnostics Division, Fernwald, Germany) were tested with our new liquid microarray method. This method successfully determined the genotypes of 74 of the 78 samples previously genotyped in the Versant (TM) HCV Genotype Assay LiPA (74/78, 95%). The concordance between the two methods was 100% for genotype determination (74/74). At the subtype level, all 3a and 2b samples gave identical results with both methods (17/17 and 7/7, respectively). Two 2c samples were correctly identified by microarray, but could only be determined to the genotype level with the Versant (TM) HCV assay. Genotype ""1'' subtypes (1a and 1b) were correctly identified by the Versant (TM) HCV assay and the microarray in 68% and 40% of cases, respectively. No genotype discordance was found for any sample. HCV was successfully genotyped with both methods, and this is of prime importance for treatment planning. Liquid microarray assays may therefore be added to the list of methods suitable for HCV genotyping. It provides comparable results and may readily be adapted for the detection of other viruses frequently co-infecting HCV patients. Liquid array technology is thus a reliable and promising platform for HCV genotyping.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Hepatitis C virus (HCV) transmission has decreased with the adoption of universal blood donor screening and social policies to reduce the risk of infection in intravenous drug users, but remains a worldwide health problem. The objective of this study was to evaluate the phylogenetic relationships among sequences from different HCV genomic regions from sexual partners of infected patients. Nine couples with a stable relationship and without other risk factors for HCV infection and 42 control patients were selected, and the NS3 and NS5B regions were analysed. Phylogenetic analysis showed that viruses from five of the couples had a common origin, clustering in the same monophyletic group, with bootstrap values greater than 70. For the other couples, monophyletic groups were observed, but without bootstrap support. Thus, using two different viral genome regions, a common source of infection was observed in both members of five couples. These data strongly support HCV transmission within couples.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Introduction: The mechanisms by which severe cholestatic hepatitis develops after liver transplantation are not fully understood. Reports on immunohistochemical distribution of hepatitis C virus (HCV) antigens are still scarce, but recently, HCV immunostaining was suggested for early diagnosis of cholestatic forms of recurrent hepatitis C in liver grafts. After purification, Rb246 pab anticore (aa1-68) yielded specific, granular cytoplasmic staining in hepatocytes. Signal amplification through the Envision-Alkaline Phosphatase System avoided endogenous biotin and peroxidase. Aims/Methods: Rb246 was applied to liver samples of explants of 12 transplant recipients, six with the most severe form of post-transplantation recurrence, severe cholestatic hepatitis (group 1) and six with mild recurrence (group 2). We also assessed immuno-reactivity at two time-points post-transplantation (median 4 and 22 months) in both groups. HCV-core Ag was semiquantified from 0 to 3+ in each time point. Serum HCV-RNA was also measured on the different time points by branched DNA. Results: In the early post-transplant time point, one patient had a mild staining (1+), two patients had a moderate staining (2+) and the other three had no staining in group 1, compared with five patients with no staining (0) and one patient with mild staining (1+) in group 2. Late post-transplant liver samples were available in nine patients, and two out of four samples in group 1 showed a mild staining, compared with no staining patients in five patients in group 2. Strikingly, on the explant samples, HCV immunostaining was strongly positive in group 1, and mildly positive in group 2. Two out of five samples showed 3+ staining, and three samples showed 2+ staining in group 1; two out of five samples showed no staining, two samples showed 1+ staining and one sample showed 2+ staining in group 2. Serum HCV-RNA was significantly higher in group 1, on both time-points post-transplantation. HCV-core Ag was not directly associated with serum HCV-RNA on the different time points. Conclusion: These preliminary results suggest that strong HCV immunostaining in the explant is predictive of more severe disease recurrence.

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background & Aims: This multi-center study aimed to prospectively evaluate the safety and efficacy of a genotype-based Pegylated Interferon alfa-2a/Ribavirin therapy in treatment-naive hepatitis C virus (HCV), positive HCV serology, and quantifiable HCV RNA, infected children. Methods: Eighteen children with genotypes 2 and 3 patients (group A) were assigned to medication for 24 weeks, and 47 children with genotypes 1, 4, 5 and 6 patients (group B) for 48 weeks. Results: Early response at week 12 was observed in 83% of group A patients and in 57% of group B patients (p <0.05). End of treatment response was achieved in 94% of patients in group A and in 57% in group B (p <0.001). Sustained virologic response was maintained in 89% of patients in group A and in 57% of patients in group B (p <0.01). Ten patients stopped prematurely the treatment, 2 for serious adverse event (acute hepatitis and thyrotoxicosis), and 8 because of no virologic response at week 24. Peginterferon alfa-2a and Ribavirin dose was adjusted in 15 patients (23%), 11 for neutropenia (17%), and 3 patients (5%), for anemia, respectively. Treatment-related adverse events included fever and flu-like symptoms (54%), irritability depression change of mood (34%), vomiting (23%), abdominal pain (38%), loss of appetite (21.5%) and dermatitis (29%). No influence on height growth was observed. Conclusions: Pegylated inteferon alfa-2a and Ribavirin treatment allowed to achieve SVR in 57% of pediatric patients with genotypes 1, 4, 5 and 6, and in 94% of genotypes 2 and 3. These results show an improved SVR as compared to reference series in adults with similar regimen. (c) 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

As a consequence of selective pressure exerted by the immune response during hepatitis C virus (HCV) infection, a high rate of nucleotide mutations in the viral genome is observed which leads to the emergence of viral escape mutants. The aim of this study was to evaluate the evolution of the amino acid (aa) sequence of the HCV nonstructural protein 3 (NS3) in viral isolates after liver transplantation. Six patients with HCV-induced liver disease undergoing liver transplantation (LT) were followed up for sequence analysis. Hepatitis C recurrence was observed in all patients after LT. The rate of synonymous (dS) nucleotide substitutions was much higher than that of nonsynonymous (dN) ones in the NS3 encoding region. The high values of the dS/dN ratios suggest no sustained adaptive evolution selection pressure and, therefore, absence of specific NS3 viral populations. Clinical genotype assignments were supported by phylogenetic analysis. Serial samples from each patient showed lower mean nucleotide genetic distance when compared with samples of the same HCV genotype and subtype. The NS3 samples studied had an N-terminal aa sequence with several differences as compared with reference ones, mainly in genotype 1b-infected patients. After LT, as compared with the sequences before, a few reverted aa substitutions and several established aa substitutions were observed at the N-terminal of NS3. Sites described to be involved in important functions of NS3, notably those of the catalytic triad and zinc binding, remained unaltered in terms of aa sequence. Rare or frequent aa substitutions occurred indiscriminately in different positions. Several cytotoxic T lymphocyte epitopes described for HCV were present in our 1b samples. Nevertheless, the deduced secondary structure of the NS3 protease showed a few alterations in samples from genotype 3a patients, but none were seen in 1b cases. Our data, obtained from patients under important selective pressure during LT, show that the NS3 protease remains well conserved, mainly in HCV 3a patients. It reinforces its potential use as an antigenic candidate for further studies aiming at the development of a protective immune response.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Cutaneous vasculitis may represent a great clinical challenge, even after careful dermatological examination and laboratory assessment. The authors present a case of cutaneous cryoglobulinemic vasculitis associated to chronic hepatitis C virus infection, pointing out the importance of the dermatological examination for diagnostic investigation. They discuss about the importance of defining the etiology and making correct classification for appropriate prognosis and treatment of cutaneous vasculitis.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The widespread incidence of hepatitis C (HCV) infection throughout the community is of concern. Although many of those infected will not suffer significantly from their infection, up to one-third will have liver disease, fatigue and oral health problems. General dental practitioners need to be aware of the precautions necessary in treating people with severe liver disease. This paper discusses the issues associated with treating patients who have HCV infection including the importance of preventive programs to reduce dental pathology and maximise oral health.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Like many positive-strand RNA viruses, replication of the hepatitis C virus (HCV) is associated with cytoplasmic membrane rearrangements. However, it is unclear which HCV Proteins induce these ultrastructural features. This work examined the morphological changes induced by expression of the HCV structural proteins, core, E1 and E2, expressed from a Semliki Forest Virus (SFV) recombinant RNA replicon. Electron microscopy of cells expressing these proteins showed cytoplasmic vacuoles containing membranous and electron-dense material that were distinct from the type I cytoplasmic vacuoles induced during SFV replicon replication. Immunogold labelling showed that the core and E2 proteins localized to the external and internal membranes of these vacuoles. At times were also associated with some of the internal amorphous material. Dual immunogold labelling with antibodies raised against the core protein and against an endoplasmic reticulum (ER)-resident protein (protein disulphide isomerase) showed that the HCV-induced vacuoles were associated with ER-labelled membranes. This report has identified an association between the HCV core and E2 proteins with induced cytoplasmic vacuoles which are morphologically similar to those observed in HCV-infected liver tissue, suggesting that the HCV structural proteins may be responsible for the induction of these vacuoles during HCV replication in vivo.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A self-modulating mechanism by the hepatitis C virus (HCV) core protein has been suggested to influence the level of HCV replication, but current data on this subject are contradictory. We examined the effect of wild-type and mutated core protein on HCV IRES- and cap-dependent translation. The wild-type core protein was shown to inhibit both IRES- and cap-dependent translation in an in vitro system. This effect was duplicated in a dose-dependent manner with a synthetic peptide representing amino acids 1-20 of the HCV core protein. This peptide was able to bind to the HCV IRES as shown by a mobility shift assay. In contrast, a peptide derived from the hepatitis B virus (HBV) core protein that contained a similar proportion of basic residues was unable to inhibit translation or bind the HCV IRES. A recombinant vaccinia-HCV core virus was used to examine the effect of the HCV core protein on HCV IRES-dependent translation in cells and this was compared with the effects of an HBV core-recombinant vaccinia virus. In CV-1 and HuH7 cells, the HCV core protein inhibited translation directed by the IRES elements of HCV, encephalomyocarditis virus and classical swine fever virus as well as cap-dependent translation, whereas in HepG2 cells, only HCV IRES-dependent translation was affected. Thus, the ability of the HCV core protein to selectively inhibit HCV IRES-dependent translation is cell-specific. N-terminal truncated (aa 1-20) HCV core protein that was expressed from a novel recombinant vaccinia virus in cells abrogated the inhibitory phenotype of the core protein in vivo, consistent with the above in vitro data.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

OBJECTIVE To estimate the prevalence of hepatitis C virus infection in Brazil’s inmate population.METHODS Systematic review on hepatitis C virus infection in the inmate population. Brazilian studies published from January 1, 1989 to February 20, 2014 were evaluated. The methodological quality of the studies was assessed using a scale of 0 to 8 points.RESULTS Eleven eligible studies were analyzed and provided data on hepatitis C virus infection among 4,375 inmates from seven states of Brazil, with a mean quality classification of 7.4. The overall hepatitis C virus prevalence among Brazilian inmates was 13.6% (ranging from 1.0% to 41.0%, depending on the study). The chances of inmates being seropositive for hepatitis C virus in the states of Minas Gerais (MG), Sergipe (SE), Mato Grosso do Sul (MS), Rio Grande do Sul (RS), Goiás (GO) and Espirito Santo (ES) were 84.0% (95%CI 0.06;0.45), 92.0% (95%CI 0.04;0.13), 88.0% (95%CI 0.09;0.18), 74.0% (95%CI 0.16;0.42), 84.0% (95%CI 0.08;0.31) and 89.0% (95%CI 0.01;0.05) respectively, lower than that observed in the Sao Paulo state (seroprevalence of 29.3%). The four studies conducted in the city of Sao Paulo revealed a lower prevalence in more recent studies compared to older ones.CONCLUSIONS The highest prevalence of hepatitis C virus infection in Brazil’s inmate population was found in Sao Paulo, which may reflect the urban diversity of the country. Despite Brazilian studies having good methodological quality to evaluate the prevalence of the hepatitis C virus, they are scarce and lack data on risk factors associated with this infection, which could support decisions on prevention and implementation of public health policies for Brazilian prisons.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The present study assessed the clinical significance of hepatitis C virus (HCV) genotypes and their influence on response to long term recombinant-interferon-alpha (r-IFN-CE="Symbol">a) therapy in Brazilian patients. One hundred and thirty samples from patients previously genotyped for the HCV and with histologically confirmed chronic hepatitis C (CH-C) were evaluated for clinical and epidemiological parameters (sex, age, time of HCV infection and transmission routes). No difference in disease activity, sex, age or mode and time of transmission were seen among patients infected with HCV types 1, 2 or 3. One hundred and thirteen of them were treated with 3 million units of r-IFN-CE="Symbol">a, 3 times a week for 12 months. Initial response (IR) was significantly better in patients with genotype 2 (100%) and 3 (46%) infections than in patients with genotype 1 (29%) (p < 0.005). Among subtypes, difference in IR was observed between 1b and 2 (p < 0.005), and between 1b and 3a (p < 0.05). Sustained response (SR) was observed in 12% for (sub)type 1a, 13% for 1b, 19% for 3a, and 40% for type 2; significant differences were found between 1b and 2 (p < 0.001), and between 1b and 3a (p < 0.05). Moreover, presence of cirrhosis was significantly associated with non response and response with relapse (p < 0.05). In conclusion, non-1 HCV genotype and lack of histological diagnosis of cirrhosis were the only baseline features associated with sustained response to treatment. These data indicate that HCV genotyping may have prognostic relevance in the responsiveness to r-IFN-CE="Symbol">a therapy in Brazilian patients with chronic HCV infection, as seen in other reports worldwide.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In order to contribute to a better understanding of the forms of acquisition of hepatitis C virus (HCV) in Brazil, with special emphasis on sexual transmission, we determined the presence of HCV infection in regular partners and in non-sexual home communicants of blood donors seen at Fundação Pró-Sangue Hemocentro de São Paulo from January 1992 to July 1996. Of 154 blood donors with HCV infection (index cases), 111 had had regular partners for at least 6 months. Sixty-eight of 111 partners were evaluated for HCV infection. Of these, 8 (11.76%) were considered to have current or previous HCV infection; a history of sexually transmissible diseases and index cases with a positive HCV-RNA test were more prevalent among partners with HCV infection. Of the 68 index cases whose partners were studied, 56 had non-sexual home communicants. Of the total of 81 home communicants, 66 accepted to be evaluated for HCV infection. None of them was HCV-positive, suggesting that the high prevalence of HCV infection among partners may be attributed at least partially to sexual transmission.