Effect of schistosomiasis and hepatitis on liver disease.
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Infection with hepatitis C virus (HCV) has become the most important public health problem in Egypt. In Egypt, viral hepatitis along with infection with Schistosoma mansoni is the major cause of chronic liver disease and liver cirrhosis. Although HCV infection is highly prevalent in Egypt, very little information is available on the distribution of the different genotypes of HCV. Our aims in this study were first to determine the prevalence of viral and parasite infections in patients with chronic liver disease and then to assess the distribution of HCV genotypes in these patients. In the present study, 151 individuals (50 with chronic liver disease, 51 with chronic diseases of organs other than the liver, and 50 apparently healthy persons) were investigated. The last 2 groups served as control groups. These individuals were subjected to routine liver function tests and detection of serum antibodies to bilharziasis, hepatitis B surface antigen (HBsAg), and HCV. Furthermore, the presence of hepatitis G virus (HGV) and HCV in the serum samples were tested for by a reverse transcription polymerase chain reaction (RT-PCR). Prevalence of different genotypes of HCV in patients positive for HCV were determined by RT-PCR using type-specific primers. Results of the study revealed that 84, 74, 12, and 20% of patients with chronic liver disease were positive for Schistosoma mansoni, HCV, HBsAg, and HGV, respectively, as compared to 51, 43.1, 2, and 4% of patients with other chronic diseases and 22, 6, 0, and 0% of apparently healthy individuals. One hundred percent of patients with chronic liver disease, 72.5% of those with other diseases, and 26% of normal controls were shown to have at least one of the studied infectious agents. Two or more of the agents were highly coincident in patients with chronic liver disease. In Egypt, HCV genotype 4a is highly prevalent, where it contributed 85% of the tested samples in comparison to 10, 2.5, and 2.5% for subtypes 1b, 2a, and 3a, respectively. In conclusion, these results suggest that in Egypt, HCV along with schistosomal parasite infection is the major risk factor for chronic liver disease. In most Egyptian patients, HCV genotype 4 is highly prevalent. (+info)
Mutational analysis of a conserved tetraloop in the 5' untranslated region of hepatitis C virus identifies a novel RNA element essential for the internal ribosome entry site function.
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The 5' untranslated region of hepatitis C virus RNA forms an extensive secondary structure including several hairpin motifs and mediates translation initiation by an internal ribosome entry site-dependent pathway. We report, here, an extensive mutagenesis analysis of a highly conserved tetraloop in the 5' untranslated region of hepatitis C virus, namely hairpin IIIe (295'-GAUA-298'). Our results demonstrate that hairpin IIIe is essential for the internal ribosome entry site function. Moreover, they indicate the importance of the primary structure of this motif because mutations in all four nucleotides of the loop caused a severe loss of internal ribosome entry site activity. These data represent the first experimental evidence for the functional significance of tetraloops in internal ribosome entry site-driven translation of hepatitis C virus. (+info)
Genotype dependence of hepatitis C virus load measurement in commercially available quantitative assays.
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Standardization and genotype independence of methods used to quantify hepatitis C virus (HCV) RNA in clinical specimens are necessary for accurate assessment of the role of HCV quantitation as a prognostic marker for HCV infection and monitoring of the response to antiviral treatment. Commercially available methods used to measure HCV loads include PCR-based (Roche Monitor) and hybridization-based (Quantiplex bDNA-2) methods. Recently, a new version of the Roche Monitor assay (version 2.0) has become available; it has been modified to achieve more equal quantitation of different HCV genotypes. Consistent with previous reports, Roche Monitor version 1.0 substantially underestimated concentrations of RNA transcripts of types 2b, 3a, 4a, 5a, and 6a and virus loads in individuals infected with genotypes 2 to 6 relative to reference tests. However, version 2.0 achieved equivalent quantitation of each genotype over a narrow quantitative range (10(3) to 5 x 10(5) copies of RNA/ml) but significantly underestimated RNA concentrations above this range. The assay showed an equivalent inability to quantify high levels of HCV RNA in plasma samples, and this was responsible for the falsely narrow range of virus loads detected in HCV-infected individuals. In contrast, the Chiron bDNA-2 assay could only measure RNA concentrations in the upper quantitative range (2 x 10(5) to 5 x 10(7) copies of RNA/ml) but showed equivalent sensitivity for genotypes 1 to 5; however, concentrations of type 6a RNA transcripts and virus loads in clinical specimens from individuals infected with type 6a were underestimated by a factor of 2 to 4. Differences were observed between PCR- and hybridization-based assays in their relative quantitation of HCV RNA transcripts and HCV genomic RNA, which may cause problems with the use of transcripts for interassay calibration. (+info)
Serological determination of hepatitis C virus subtypes 1a, 1b, 2a, 2b, 3a, and 4a by a recombinant immunoblot assay.
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Serological determination of hepatitis C virus (HCV) subtypes has been hampered by the lack of suitable assays. Therefore, a recombinant immunoblot assay has been established for serological differentiation of HCV subtypes 1a, 1b, 2a, 2b, 3a, and 4a. It consists of recombinant HCV proteins from the NS-4 region propagated in Escherichia coli. To confirm the serotyping assay results, the results were compared with those obtained by nucleotide sequencing of the NS-5 region. Sera from 157 patients with chronic HCV infection were examined by this assay, and specific antibodies could be detected in 86% (n = 135) of them. The HCV genotype was determined correctly in all but one sample, and the subtypes determined by the serotyping assay corresponded to the HCV subtypes detected by nucleotide sequencing for 95% (n = 128) of the samples. These data indicate that HCV subtypes can be distinguished serologically. The assay that is described provides an easier means of identification of infection with different HCV subtypes for wider clinical and epidemiological applications. (+info)
Determination of hepatitis C virus genotype by direct sequence analysis of products generated with the Amplicor HCV test.
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Consistent with other members of the family Flaviviridae, hepatitis C virus (HCV) demonstrates a high degree of sequence variation throughout the coding regions of its genome. However, there is a high degree of sequence conservation found within the 5' untranslated region (UTR) of the genome, making this region a target of choice for most nucleic acid amplification-based detection assays. In this study, the Amplicor HCV test, a commercially available assay which detects the 5'UTR, was used for the detection of HCV RNA in 669 serum samples obtained from a cohort of liver transplantation patients. Amplification products obtained from the HCV-positive cases were subjected to direct sequencing and genotyping based upon seven phylogenetically informative regions within the 5'UTR. Of the 669 specimens, 416 (62.2%) tested positive for the presence of HCV RNA. Of these, 372 (89.4%) specimens were successfully classified into 11 HCV genotypes and subtypes after computer-assisted analysis of the sequence data. Forty-four (10.6%) of the HCV RNA-positive specimens were not classifiable, the majority corresponding to low-titer specimens as determined by the Chiron Quantiplex HCV RNA 2. 0 assay. Additional comparative studies targeting the NS-5 region of the viral genome generally confirmed the accuracy and sensitivity of the 5'UTR-based classifications, with the exception of the misclassification of a small number of type 1a cases as type 1b. We conclude that although the high sequence conservation within the 5'UTR results in the misclassification of a small number of HCV subtypes, the overall gains of efficiency, the shorter turnaround time, the inclusion of contamination control measures, and the low rate of test failure compared to that of methods based on the NS-5 gene together constitute significant advantages over other techniques. (+info)
Diagnostic value of anti-hepatitis C virus (HCV) core immunoglobulin M in recurrence of HCV infection after orthotopic liver transplantation.
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The significance of anti-hepatitis C virus (HCV) core immunoglobulin M (IgM) and its relationship with genotypes, alanine aminotransferase abnormality, and histological data were studied for 18 patients who had undergone orthotopic liver transplantation due to HCV-related end-stage disease. During follow-up, IgM response seemed to be associated with the recurrence of HCV infection but did not correlate with abnormal alanine aminotransferase levels and histological data. In addition, the results of this study indicated that the detection of HCV RNA is critical for diagnosis of reinfection in liver transplantation. (+info)
Apical hypertrophic cardiomyopathy and hepatitis C virus infection.
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The familial form of hypertrophic cardiomyopathy (HCM) is attributed to mutations in the genes for contractile proteins, but the etiology of non-familial form remains unknown. This study was designed to examine the clinical features, histopathologic changes, and hepatitis C virus (HCV) genomes in patients with HCM associated with HCV infection. Anti-HCV antibody was present in the sera of 9 of 65 patients (13.8%) with HCM versus 2.41% in a control population of voluntary blood donors in Japan, a statistically significant difference (p<0.0001). Among these 9 patients, 6 had ace-of-spades-shaped deformities of the left ventricle with apical hypertrophy. Myocardial fibrosis was found in all patients, and mild cellular infiltration was observed in 5 patients. Type 1b HCV RNA was present in the sera of 5 of the 9 patients. The copy number of HCV was 5.5x10(3)-8.6x10(5) genomes/ml serum, and multiple clones of HCV were detected in the sera of each patient by an analysis of the hypervariable regions using fluorescent single-strand conformation polymorphism. Positive strands of HCV were found in the hearts of 5 patients, and negative strands in the hearts of 2 patients. A high prevalence of HCV infection was found in patients with HCM, particularly of the apical variety, suggesting that HCV is an important causal agent in the pathogenesis of the disease. (+info)
Efficacy and changes of the nonstructural 5A GENE by prolonged interferon therapy for patients with hepatitis C virus genotype 1b and a high level of serum HCV-RNA.
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OBJECT: The aim of this study was to examine the efficacy and the changes of amino acid sequences of the interferon sensitivity-determining region (ISDR) by prolonged interferon (IFN) treatment in patients who have serum hepatitis C virus (HCV)-genotype 1b and a high level of serum HCV-RNA. METHODS: Inclusion criteria were biopsy-proven chronic hepatitis, positive HCV-RNA, and an abnormal serum aminotransferase level. Twenty-five patients received 6 MU of natural IFN-alpha daily for 8 weeks, followed by three times weekly for 40 weeks (1,056 MU). One patient was withdrawn from the study due to IFN side effects. Therefore, the remaining 24 patients (group 1) were studied the efficacy of IFN administration and changes of ISDR. As a control, 22 patients (group 2) treated with natural IFN-alpha for 24 weeks for the same period were studied retrospectively. Patients were defined as complete responders (CR) if serum HCV-RNA levels were negative for 6 months after IFN therapy. RESULTS: According to this criterion, CR was 25% (6/24) in group 1 and 9.1% (2/22) in group 2. The normalization rates of alanine aminotransferease (ALT) for six months after termination of IFN was 41% (10/24) in group 1 and 18.2% (4/22) in group 2. Regarding the changes of ISDR in patients with no CR, the change rates of ISDR were 16.7% (3/18) in group 1 and 10% (2/20) in group 2. CONCLUSION: We concluded that prolonged IFN therapy was effective for patients with HCV-genotype 1b and a high level of serum HCV-RNA. (+info)