Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The detection of antibody to the hepatitis C virus C100-3 antigen from the nonstructural region (NS3/NS4) of the viral genome was the first useful marker developed to detect past or potentially active infection with the hepatitis C virus. A systematic epitope survey of the nonstructural region has uncovered other immunogenic antigens. In order to assess the possible diagnostic utility of these antigens, their reactivity against a limited panel of sera from patients with chronic liver disease due to hepatitis C virus and other etiologies was tested. Antibody assays were performed using an immunoblot plaque assay and an enzyme-linked immunosorbent assay (ELISA). In a study of 16 C100-3-reactive individuals, all 16 patients were reactive using the plaque assay for the NS3 3' (409-1-1) and NS3 5' (C33u). In this same group of patients, antibodies by ELISA were reactive to NS3 3' in 12 of 16 patients (75%), NS3 5' in 15 of 16 patients (93%), and a capsid antigen (NC450) in 14 of 16 patients. In a group of five patients who were diagnosed with cryptogenic liver disease (C100-3 negative), 4 of 5 patients were reactive for antibody to all of the above epitopes. In a survey of 23 patients with other forms of chronic liver disease (nonviral liver disease, hepatitis B, alcoholic liver disease, cholestatic liver disease, and autoimmune hepatitis), only 1 of 23 patients was reactive for antibody to the C100-3 and 4 of 23 patients were reactive for antibodies to structural and nonstructural regions of the virus.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Variation in antibody reactivity to the hepatitis C virus by comparative immunoscreening and enzyme immunoassay. 768 14

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of anti-HCV antibody. We assayed for antibodies against either oligopeptide (S29-1) deduced from the nucleocapsid gene or the product of nonstructural region (NS3) synthesized in a recombinant Escherichia coli (S4). To reduce false-positive results induced by non-specific binding of antibodies with a carrier protein and to increase the sensitivity of an immunoassay, non-fused S4 peptide was prepared by the recombinant DNA technique and site-specific proteolysis (by factor Xa). In 71 non-A, non-B hepatitis patients with chronic liver disease, 70 (98.5%) were positive by S29-1/S4 ELISA as well as by a second-generation test (Abbott II). On the other hand, of 40 serum samples from blood donors, in which anti-N14 (core) and C100-3 antibodies were not detected but hepatitis C virus (HCV) RNA was detectable by polymerase chain reaction (PCR), 24 (60%) were positive by S29-1/S4 ELISA, whereas only 18 (45%) were diagnosed by Abbott II. In addition, based on results in a small group of 92 blood donors, detection of anti-S29-1/S4 antibody correlated well with HCV viremia as confirmed by PCR. These results indicated that the preparation of nonfused protein (S4) by recombinant DNA technique and a combination of S29-1 and S4 as immobilized antigens in an ELISA provide a sensitive and specific diagnosis for HCV infection with good correlation with the presence of viral RNA as confirmed by PCR.
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PMID:A sensitive serodiagnosis of hepatitis C virus (HCV) infection with two non-fused peptides: comparison of antibody responses detected with a newly developed assay and a commercial second-generation test. 768 47

Hepatitis C virus (HCV) antigen expression was examined by immunohistochemical staining in liver tissue taken at biopsy from 8 anti-HCV positive patients. Frozen liver sections were stained by indirect immunofluorescence for capsid, E2/NS1, NS3, NS4 and NS5 using polyclonal antibodies raised to synthetic peptides from these regions. The antigens E2 and NS3 were localised in scattered hepatocytes and also in cells within and around areas of inflammation. A weaker signal was observed for NS4 and NS5 and no signal was seen for capsid antigen. No staining was seen in liver tissue from 9 individuals, including 3 hepatitis B virus-positive and 2 hepatitis delta virus/positive patients, who were negative for serological markers of HCV. The specificity of the staining reaction was also confirmed by the lack of staining in HCV-positive liver samples, after the antisera was pre-adsorbed against the specific peptide. Collectively, the data suggests that HCV may not only be hepatotropic but also lymphotropic, and this may be an important factor in the pathogenesis of HCV infection.
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PMID:Localisation of hepatitis C virus proteins in infected liver tissue by immunofluorescence. 768 8

The serodiagnosis of hepatitis C virus (HCV) infection was analyzed by a recombinant immunoblot assay (RIBA) with recombinant proteins encoded by the viral RNA isolated from our patients in Hamburg, Germany. The HCV RNA was amplified by PCR, and proteins encoded by the viral core and the NS3, NS4, and NS5 regions were expressed subsequently in Escherichia coli. The results obtained with our UKE RIBA were compared with the results of the Abbott HCV second-generation enzyme immunoassay (EIA). Serum samples from 270 patients, which were sent to us on the suspicion of HCV hepatitis and which were negative for hepatitis A virus and hepatitis B virus antibodies, were examined. In 227 cases (84.1%), there were identical positive (204 cases, 75.6%) or negative (23 cases, 8.5%) results in both tests. In 32 cases (11.9%), the reactive Abbott second-generation HCV EIA results could not be confirmed by the UKE RIBA and the HCV PCR. In follow-up studies conducted over 1 year, these results did not change. In three cases (1.1%), the UKE RIBA presented a positive result while the Abbott second-generation HCV EIA was negative. All three cases were positive in the HCV PCR and showed seroconversion in an HCV EIA 4 to 6 weeks later. In addition, 33 patient serum samples were examined by UKE RIBA in parallel with the Ortho RIBA 2.0. In three cases (9.1%), a positive Ortho RIBA 2.0 result could not be confirmed by the UKE RIBA and the HCV PCR. All three patients were free of complaints. The UKE RIBA showed also a smaller number of indeterminate results (3.0%) than the Ortho RIBA 2.0 (24.2%). This comparison study demonstrates that the commercially available HCV antibody tests should be further improved.
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PMID:Study on reliability of commercially available hepatitis C virus antibody tests. 775 66

The partial genome sequence of the hepatitis C virus (HCV) was determined in the serum of a Taiwanese patient with chronic community-acquired type C hepatitis. The cDNA fragments synthesized with the HCV RNA as a template were amplified by polymerase chain reaction using specific oligonucleotide primers. The amplified fragments represented the regions coding for the putative core, matrix and envelope proteins as well as the N-terminal amino acid sequence of the nonstructural protein NS1, the partial nonstructural NS3 and NS4 proteins and the region of the partial 5'-end noncoding sequence. The cDNA fragments were cloned and sequenced. Sequence analysis of these clones showed that they share 83.7%, 93.2% and 93.6% similarity at the nucleotide level, and 86.6%, 94.1% and 92.9% homology at the amino acid level, with the previously published American, Japanese and Taiwanese isolates, respectively. Accordingly, the RNA genome we obtained is HCV type II, probably, the predominant subtype in Taiwan.
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PMID:Sequence determination of hepatitis C virus genome isolated from Taiwan. 786 53

From a blood serum of patients with chronic posttransfusional non-A, non-B hepatitis the genomic RNA of hepatitis C virus (HCV) was isolated. Using RT-PCR (reverse transcription-polymerase chain reaction) there were synthesized and cloned cDNA fragments, representing 3 regions of the genome of a new virus isolate (HCV-R): 5'-nontranslating region, a core gene and a part of the nonstructural region NS3/NS4. Analysis of the nucleotide and of the amino acid sequences of a core and NS3/NS4 regions revealed significant difference between isolates from Russia (HCV-R) and from Japan (HCV-J). Nucleotide sequence homology between them was 90.0-90.87%, while homology between Russian and American isolates (USA-PT) complised 95.27-97.32%. No essential variations were found in the nucleotide sequences of 5'-nontranslating region of all three HCV isolates.
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PMID:[Determination of the nucleotide sequence of the Russian variant of the hepatitis C virus]. 813 50

A pool of murine monoclonal antibodies developed against c100 antigen, a hepatitis C virus-associated protein encoded by the NS3/NS4 virus genome, was used to detect hepatitis C virus in liver biopsy specimens from patients with acute and chronic hepatitis C virus infection. The antigen was present in the cytoplasm of liver cells only. The immunoreactive signal appeared as large, distinct, brilliant fluorescent granules with no clear relationship to cellular structures. No obvious membrane c100 antigen accumulation was observed. Distribution of c100-containing hepatocytes was directly correlated with viral replication in acute hepatitis. All three acute-hepatitis patients were positive for hepatitis C virus RNA (as detected on polymerase chain reaction) in serum and displayed c100 antigen in 50% to 70% of hepatocytes, with a distinct topographical relationship with necrotic areas and inflammatory cell accumulation. Conversely, very low numbers of infected cells and no relationship between tissue c100 antigen expression and sites of liver cell necrosis and inflammation were found in 14 chronic hepatitis C virus infection patients. Furthermore, though all patients had measurable levels of serum hepatitis C virus RNA, only eight (57%) had detectable c100 antigen in liver sections. Indeed, these two distinct immunopathological patterns were inversely related to the development of c100 antibody in serum. Specificity of hepatocellular c100 antigen deposits was established through extensive absorption experiments using structural and nonstructural hepatitis C virus recombinant proteins. However, tissue processing was found to be a crucial step in the demonstration of hepatitis C virus antigen in fresh frozen liver tissue.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Hepatitis C virus c100 antigen in liver tissue from patients with acute and chronic infection. 834 53

Hepatitis C virus (HCV) is the major etiological agent of both parenterally transmitted and sporadic non-A, non-B hepatitis. The disease is a major health problem with an estimated 50 million people infected worldwide, a high percentage of whom become chronically infected and are at high risk for liver cirrhosis. The serine protease contained within the N-terminal region of the nonstructural protein 3 (NS3 protease) of HCV is considered a promising target for the development of an antiviral therapy. A prime requisite to study in detail the biochemistry of the protease as well as develop inhibitors is the availability of a fast and sensitive in vitro assay of enzyme activity. However, due to their low kcat/Km values, synthetic peptide substrates based on the natural cleavage sites appear unsuitable for this purpose. We show here that appropriate substrates can be obtained by substituting the scissile amide bond with an ester linkage. The resulting depsipeptides show >100-fold improvement in kcat/Km values, up to 13,000 M-1 s-1, enabling detection of activity with subnanomolar NS3 concentrations. The ester substrates are obtained in high yield entirely by solid-phase synthesis using commercially available materials, without the need for any preassembled building blocks.(c) 1996 Academic Press, Inc.
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PMID:Synthetic depsipeptide substrates for the assay of human hepatitis C virus protease. 866 May 72

The genomes of two novel members of the Flaviviridae associated with GB agent hepatitis (GB viruses A and B) were cloned and sequenced recently. The genome of a third novel virus (GB virus C), related to but distinct from GB viruses A and B, has also been identified and characterized. Overlapping clones encompassing the large open reading frames of these three viruses have been expressed in E. coli as CTP:CMP-3-deoxy-D-manno-octulosonate cytidylyltransferase (CKS) fusion proteins. Bacterial lysates were subjected to Western blot analyses using sera from GB agent-infected tamarins and human sera from various individuals with or "at risk" for non-A, non-B, non-C, non-D, non-E hepatitis. Antigenic regions were identified in the putative NS3, NS4, and NS5 proteins from all three viruses. An antigenic region was also identified in the putative core protein of GB virus B. Many of the clones identified originally as encoding antigenic proteins were quite large. To map these regions more narrowly, smaller overlapping clones were generated by polymerase chain reaction (PCR), expressed as recombinant CKS fusion proteins and tested by Western blot. Additionally, a lambda gt11 expression library was generated from infectious tamarin sera and immunoscreened. These studies have identified at least three epitopes in GB virus A, five epitopes in GB virus B and four epitopes in GB virus C.
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PMID:Identification of antigenic regions in the GB hepatitis viruses GBV-A, GBV-B, and GBV-C. 869 65

The recent cloning and genomic identification of hepatitis C virus (HCV) by sensitive and specific immune techniques has allowed a better definition of both histopathological and clinical features of the previously not well defined non-A, non-B hepatitis. In this regard, antibodies to different HCV antigens are usually found during infection, even if some of them such as anti-E1 and anti-E2/NS1 have been shown to be associated with significant viraemic levels. Acute hepatitis C is self-limiting in a minority of cases only. Over 60% of acute hepatitis becomes in fact chronic and may progress towards cirrhosis. In about 10% of cases, hepatocellular carcinoma may develop in cirrhotic livers. The occurrence of a strict relationship between immunoresponsiveness and disease activity is suggested by the observation that peripheral blood mononuclear cell (PBMC) proliferation induced by NS3 structure is associated with self-limiting acute hepatitis, while PBMC stimulation by core antigen characterizes chronic C hepatitis. The demonstration of lymphoid aggregates, bile duct lesions, intraportal lymphocyte infiltration, increased adhesion molecule expression and augmented cytokine release clearly emphasizes the involvement of immune-mediated reactions in the development of liver damage, even if a direct cytopathic effect cannot be excluded. Finally, it is likely that HCV may favour, through immune-mediated mechanisms, autoantibody generation and/or the appearance of some extrahepatic autoimmune manifestations during the course of HCV chronic infection.
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PMID:Hepatitis C virus infection. Biological and immunological features. 876 58


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