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Mejer N, Galli A, Ramirez S, Fahnøe U, Benfield T, Bukh J. Ribavirin inhibition of cell-culture infectious hepatitis C genotype 1-3 viruses is strain-dependent. Virology 2019; 540:132-140. [PMID: 31778898 DOI: 10.1016/j.virol.2019.09.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 09/27/2019] [Accepted: 09/27/2019] [Indexed: 12/20/2022]
Abstract
Ribavirin remains relevant for successful treatment of chronic hepatitis C virus (HCV) infections in low-income settings, as well as for therapy of difficult-to-treat HCV patients. We studied the effect of ribavirin against cell-culture adapted HCV of genotypes 1, 2 and 3, representing ~80% of global infections. TNcc(1a) was the most sensitive to ribavirin, while J6/JFH1(2a) was the most resistant. EC50s ranged from 21 μM (95%CI: 20-22 μM) to 189 μM (95%CI: 173-207 μM). Substitutions at position 415 of NS5B resulted in little or no change to ribavirin sensitivity (0.7-0.9 fold) but conferred moderate drug resistance during extended treatment of genotype 1 (1.8-fold). NS5A and NS5B sequences could alter ribavirin sensitivity 2-4-fold, although their contribution was not simply additive. Finally, we detected limited accumulation of mutations associated with ribavirin treatment. Our findings show that the antiviral effect of ribavirin on HCV is strain-dependent and is influenced by the specific sequence of multiple HCV nonstructural proteins.
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Affiliation(s)
- Niels Mejer
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Infectious Diseases, Hvidovre Hospital, Hvidovre, Denmark
| | - Andrea Galli
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Infectious Diseases, Hvidovre Hospital, Hvidovre, Denmark
| | - Santseharay Ramirez
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Infectious Diseases, Hvidovre Hospital, Hvidovre, Denmark
| | - Ulrik Fahnøe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Infectious Diseases, Hvidovre Hospital, Hvidovre, Denmark
| | - Thomas Benfield
- Department of Infectious Diseases, Hvidovre Hospital, Hvidovre, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Infectious Diseases, Hvidovre Hospital, Hvidovre, Denmark.
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Gewaid H, Mesalam AA, Ibrahim AA, Abdel Shafy DN, Abdel Shafy RN, Emara N, Hamdy SM, Gewaid M, Bahgat MM. Establishment of a platform for molecular and immunological characterization of the RNA-dependent-RNA-polymerase NS5B of an Egyptian HCV isolate. J Med Virol 2017; 90:545-558. [PMID: 29064582 DOI: 10.1002/jmv.24977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Accepted: 10/16/2017] [Indexed: 11/09/2022]
Abstract
The present work aimed at establishing a platform to enable frequent characterization of the HCV RNA-dependent-RNA-polymerase from Egyptian clinical isolates. Subjecting amplified HCV-NS5B coding gene from Egyptian patient's serum to sequencing, multiple alignment, and phylogenetic analysis confirmed its subtype 4a origin. Nucleotide sequence analysis revealed presence of an additional start codon at the beginning of the NS5B gene. Peptide sequence alignment demonstrated presence of unique amino acid residues in our 4a-NS5B sequence distinct from the JFH-1-NS5B sequence as well as unique amino acids compared to other genotypes. The distinct molecular structure of the herein characterized 4a-NS5B from the 2a-JFH-1-NS5B was further demonstrated both in the built 3D models and the Ramachandran plots corresponding to each structure. Both the unique amino acid residues and 3D structure of the 4a-NS5B may influence both genotype 4a replication rate and response to therapy in comparison to other genotypes. Many resistance mutations to polymerase inhibitors were found both in ours and other genotypes' sequences. The presence of the required amino acid motifs for the RNA dependent RNA polymerase activity encouraged to clone the NS5B570-encoding sequence downstream CMV promotor in a mammalian expression vector. Such construct was used for both prokaryotic expression in bacteria and for DNA immunization. Successful mammalian expression and induction of specific immune response were demonstrated by ELISA and Western blotting. The potential of both the raised antibodies and the expressed NS5B to differentiate between HCV-infected and control human sera were demonstrated which reflect their diagnostic value.
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Affiliation(s)
- Hossam Gewaid
- Research Group Immune- and Bio-markers for Infection, the Center of Excellence for Advanced Sciences, the National Research Center, Cairo, Egypt.,Therapeutic Chemistry Department, the National Research Center, Cairo, Egypt
| | - Ahmed A Mesalam
- Research Group Immune- and Bio-markers for Infection, the Center of Excellence for Advanced Sciences, the National Research Center, Cairo, Egypt.,Therapeutic Chemistry Department, the National Research Center, Cairo, Egypt
| | - Ahmed A Ibrahim
- Research Group Immune- and Bio-markers for Infection, the Center of Excellence for Advanced Sciences, the National Research Center, Cairo, Egypt.,Therapeutic Chemistry Department, the National Research Center, Cairo, Egypt
| | - Dina N Abdel Shafy
- Research Group Immune- and Bio-markers for Infection, the Center of Excellence for Advanced Sciences, the National Research Center, Cairo, Egypt.,Water Pollution Research Department, the National Research Center, Cairo, Egypt
| | - Rola N Abdel Shafy
- Research Group Immune- and Bio-markers for Infection, the Center of Excellence for Advanced Sciences, the National Research Center, Cairo, Egypt.,Therapeutic Chemistry Department, the National Research Center, Cairo, Egypt
| | - Nahed Emara
- Clinical and Chemical Pathology Department, the National Research Center, Cairo, Egypt
| | - Soha M Hamdy
- Division of Biochemistry, Faculty of Science, Fayoum University, Cairo, Egypt
| | | | - Mahmoud M Bahgat
- Research Group Immune- and Bio-markers for Infection, the Center of Excellence for Advanced Sciences, the National Research Center, Cairo, Egypt.,Therapeutic Chemistry Department, the National Research Center, Cairo, Egypt
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Genetic Variability of Hepatitis C Virus (HCV) 5' Untranslated Region in HIV/HCV Coinfected Patients Treated with Pegylated Interferon and Ribavirin. PLoS One 2015; 10:e0125604. [PMID: 25932941 PMCID: PMC4416933 DOI: 10.1371/journal.pone.0125604] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 03/24/2015] [Indexed: 01/03/2023] Open
Abstract
Association between hepatitis C virus (HCV) quasispecies and treatment outcome among patients with chronic hepatitis C has been the subject of many studies. However, these studies focused mainly on viral variable regions (E1 and E2) and usually did not include human immunodeficiency virus (HIV)-positive patients. The aim of the present study was to analyze heterogeneity of the 5' untranslated region (5'UTR) in HCV/HIV coinfected patients treated with interferon and ribavirin. The HCV 5'UTR was amplified from serum and peripheral blood mononuclear cells (PBMC) samples in 37 HCV/HIV coinfected patients treated for chronic hepatitis C. Samples were collected right before treatment, and at 2, 4, 6, 8, 12, 20, 24, 36, 44, 48, 60, and 72 weeks. Heterogeneity of the 5'UTR was analyzed by single strand conformational polymorphism (SSCP), cloning and sequencing. Sustained virological response (SVR) was achieved in 46% of analyzed HCV/HIV co-infected patients. Stable SSCP band pattern was observed in 22 patients (62.9%) and SVR rate among these patients was 23%. Decline in the number of bands and/or shift in band positions were found in 6 patients (17.1%), 5 (83%) of whom achieved SVR (p=0.009). A novel viral genotype was identified in all but one of these patients. In 5 of these 6 patients a new genotype was dominant. 5'UTR heterogeneity may correlate with interferon and ribavirin treatment outcome. In the analyzed group of HCV/HIV coinfected patients, viral quasispecies stability during treatment favored viral persistence, whereas decrease in the number of variants and/or emergence of new variants was associated with SVR. Among injection drug users (IDU) patients, a new genotype may become dominant during treatment, probably due to the presence of mixed infections with various strains, which have different susceptibility to treatment.
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Ribavirin at the Era of Novel Direct Antiviral Agents for the Treatment of Hepatitis C Virus Infection: Relevance of Pharmacological Monitoring. ACTA ACUST UNITED AC 2014. [DOI: 10.1155/2014/493087] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Ribavirin is often used for the treatment of hepatitis C virus (HCV) infection. Although its mechanisms of action remain to be clearly elucidated, ribavirin plays a beneficial role for achieving virological response and decreasing the rate of virological relapse after treatment cessation. However, ribavirin may induce side effects leading to early treatment discontinuation. Among them, hemolytic anemia is the most frequent and results from intraerythrocyte accumulation. Pharmacological studies have shown that early ribavirin exposure assessed by the area under the curve (AUC) at day 0 and ribavirin trough concentration during the first three months of therapy were correlated with sustained virological response (SVR). These studies highlighted the relevance of ribavirin pharmacologic monitoring and early dose adaptation during therapy. Although the role of ribavirin within new direct acting antiviral (DAA) combinations will probably decrease in the future, its potential benefit in difficult-to-treat patients such as patients with severe hepatopathy or patients who failed triple therapy including patients with multiresistance will need to be further investigated.
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El-Shamy A, Hotta H. Impact of hepatitis C virus heterogeneity on interferon sensitivity: an overview. World J Gastroenterol 2014; 20:7555-69. [PMID: 24976696 PMCID: PMC4069287 DOI: 10.3748/wjg.v20.i24.7555] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 02/18/2014] [Accepted: 04/21/2014] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) is a major cause of liver disease worldwide. HCV is able to evade host defense mechanisms, including both innate and acquired immune responses, to establish persistent infection, which results in a broad spectrum of pathogenicity, such as lipid and glucose metabolism disorders and hepatocellular carcinoma development. The HCV genome is characterized by a high degree of genetic diversity, which can be associated with viral sensitivity or resistance (reflected by different virological responses) to interferon (IFN)-based therapy. In this regard, it is of importance to note that polymorphisms in certain HCV genomic regions have shown a close correlation with treatment outcome. In particular, among the HCV proteins, the core and nonstructural proteins (NS) 5A have been extensively studied for their correlation with responses to IFN-based treatment. This review aims to cover updated information on the impact of major HCV genetic factors, including HCV genotype, mutations in amino acids 70 and 91 of the core protein and sequence heterogeneity in the IFN sensitivity-determining region and IFN/ribavirin resistance-determining region of NS5A, on virological responses to IFN-based therapy.
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Naghi SE, Abdel-Ghaffar TY, El-Karaksy H, Abdel-Aty EF, El-Raziky MS, Allam AA, Helmy H, El-Araby HA, Behairy BE, El-Guindi MA, El-Sebaie H, Abdel-Ghaffar AY, Ehsan NA, El-Hennawy AM, Sira MM. Safety and efficacy of Hansenula-derived PEGylated-interferon alpha-2a and ribavirin combination in chronic hepatitis C Egyptian children. World J Gastroenterol 2014; 20:4681-4691. [PMID: 24782620 PMCID: PMC4000504 DOI: 10.3748/wjg.v20.i16.4681] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Revised: 01/07/2014] [Accepted: 03/04/2014] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the safety and efficacy of a Hansenula-derived PEGylated (polyethylene glycol) interferon (IFN)-alpha-2a (Reiferon Retard) plus ribavirin customized regimen in treatment-naïve and previously treated (non-responders and relapsers) Egyptian children with chronic hepatitis C infection. METHODS Forty-six children with chronic hepatitis C virus (HCV) infection were selected from three tertiary pediatric hepatology centers. Clinical and laboratory evaluations were undertaken. Quantitative polymerase chain reaction (PCR) for HCV-RNA was performed before starting treatment, and again at 4, 12, 24, 48, 72 wk during treatment and 6 mo after treatment cessation. All patients were assigned to receive a weekly subcutaneous injection of PEG-IFN-alpha-2a plus daily oral ribavirin for 12 wk. Thirty-four patients were treatment-naïve and 12 had a previous treatment trial. Patients were then divided according to PCR results into two groups. Group I included patients who continued treatment on a weekly basis (7-d schedule), while group II included patients who continued treatment on a 5-d schedule. Patients from either group who were PCR-negative at week 48, but had at least one PCR-positive test during therapy, were assigned to have an extended treatment course up to 72 wk. The occurrence of adverse effects was assessed during treatment and follow up. The study was registered at www.ClinicalTrials.gov (NCT02027493). RESULTS Only 11 out of 46 (23.9%) patients showed a sustained virological response (SVR), two patients were responders at the end of treatment; however, they were lost to follow up at 6 mo post treatment. Breakthrough was seen in 18 (39.1%) patients, one patient (2.17%) showed relapse and 14 (30.4%) were non-responders. Male gender, short duration of infection, low viral load, mild activity, and mild fibrosis were the factors related to a better response. On the other hand, patients with high viral load and absence of fibrosis failed to respond to treatment. Before treatment, liver transaminases were elevated. After commencing treatment, they were normalized in all patients at week 4 and were maintained normal in responders till the end of treatment, while they increased again significantly in non-responders (P = 0.007 and 0.003 at week 24 and 72 respectively). The 5-d schedule did not affect the response rate (1/17 had SVR). Treatment duration (whether 48 wk or extended course to 72 wk) gave similar response rates (9/36 vs 2/8 respectively; P = 0.49). Type of previous treatment (short acting IFN vs PEG-IFN) did not affect the response to retreatment. On the other hand, SVR was significantly higher in previous relapsers than in previous non-responders (P = 0.039). Only mild reversible adverse effects were observed and children tolerated the treatment well. CONCLUSION Reiferon Retard plus ribavirin combined therapy was safe. Our customized regimen did not influence SVR rates. Further trials on larger numbers of patients are warranted.
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Identification of alpha interferon-induced envelope mutations of hepatitis C virus in vitro associated with increased viral fitness and interferon resistance. J Virol 2013; 87:12776-93. [PMID: 24049176 DOI: 10.1128/jvi.00901-13] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Alpha interferon (IFN-α) is an essential component of innate antiviral immunity and of treatment regimens for chronic hepatitis C virus (HCV) infection. Resistance to IFN might be important for HCV persistence and failure of IFN-based therapies. Evidence for HCV genetic correlates of IFN resistance is limited. Experimental studies were hampered by lack of HCV culture systems. Using genotype (strain) 1a(H77) and 3a(S52) Core-NS2 JFH1-based recombinants, we aimed at identifying viral correlates of IFN-α resistance in vitro. Long-term culture with IFN-α2b in Huh7.5 cells resulted in viral spread with acquisition of putative escape mutations in HCV structural and nonstructural proteins. Reverse genetic studies showed that primarily amino acid changes I348T in 1a(H77) E1 and F345V/V414A in 3a(S52) E1/E2 increased viral fitness. Single-cycle assays revealed that I348T and F345V/V414A enhanced viral entry and release, respectively. In assays allowing viral spread, these mutations conferred a level of IFN-α resistance exceeding the observed fitness effect. The identified mutations acted in a subtype-specific manner but were not found in genotype 1a and 3a patients, who failed IFN-α therapy. Studies with HCV recombinants with different degrees of culture adaptation confirmed the correlation between viral fitness and IFN-α resistance. In conclusion, in vitro escape experiments led to identification of HCV envelope mutations resulting in increased viral fitness and conferring IFN-α resistance. While we established a close link between viral fitness and IFN-α resistance, identified mutations acted via different mechanisms and appeared to be relatively specific to the infecting virus, possibly explaining difficulties in identifying signature mutations for IFN resistance.
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Bolcic F, Laufer N, Torres C, Cassino L, Reynoso R, Quarleri J. Longitudinal analysis of the 5'UTR, E2-PePHD and NS5A-PKRBD genomic regions of hepatitis C virus genotype 1a in association with the response to peginterferon and ribavirin therapy in HIV-coinfected patients. Antiviral Res 2012; 95:72-81. [PMID: 22683884 DOI: 10.1016/j.antiviral.2012.05.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 05/22/2012] [Accepted: 05/26/2012] [Indexed: 12/16/2022]
Abstract
BACKGROUND The rate of non-response to pegylated interferon plus ribavirin (peg-IFN+RBV) in HCV/HIV coinfected patients is higher than in HCV-monoinfected patients. In this sense, the contribution of HCV genetic variability is unknown. The 5' untranslated (5'UTR), the nonstructural 5A (NS5A) and the second envelope (E2) HCV genomic regions have been implicated to peg-IFN therapy response. The proteins appear to block interferon (IFN)-induced RNA-dependent protein kinase (PKR) and the 5'UTR may influence the viral lymphotropism. METHODS We examined comparatively the pretreatment HCV variability between HIV coinfected and HCV monoinfected patients as well as assessed longitudinally the impact of peg-IFN+RBV on HCV variability when HIV is co-present. For this purpose, 15 HIV coinfected and 20 HCV monoinfected patients were compared. They were peg-IFN+RBV non-responders and infected with HCV 1a. RESULTS Irrespectively of the HIV-coexistence, at baseline the amino acid variation in the NS5A-related domains was significantly higher than in the E2-PePHD (p<0.001). The number of amino acid variations (mean±SD) at the NS5A-ISDR domain was higher among HCV/HIV patients than HCV-monoinfected ones (1.80±0.77 vs. 0.95±1.05; p=0.009) but such difference was slightly lower when comparing NS5A-PKRBD sequences (2.47±1.13 vs. 1.60±1.57; p=0.06). No differences were found at the E2-PePHD (0±0 vs. 0.2±0.4). At intra-HIV coinfected patient level, only minor (HCV genetic analysis) or no (HCV substitution rate and quasispecies heterogeneity) changes were observed during therapy (basal, 24h, 4weeks, and 12weeks). CONCLUSIONS Among HCV-1a/HIV coinfected and HCV-monoinfected peg-IFN+RBV non-responder patients, the HCV variability at the 5'UTR, E2-PePHD and NS5A-PKRBD/ISDR domains was mostly comparable exhibiting a low number of variations. Four well-defined amino acid substitutions in NS5A-ISDR domain appeared most frequently when HIV coexists. The interferon-based therapy did not exert any effect in the variation, selection or diversity in the above mentioned HCV regions that could influence clinical responsiveness to IFN therapy.
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Affiliation(s)
- Federico Bolcic
- Instituto de Investigaciones Biomédicas en Retrovirus y Sida, Facultad de Medicina, Universidad de Buenos Aires, Argentina
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Chayama K, Hayes CN, Yoshioka K, Moriwaki H, Okanoue T, Sakisaka S, Takehara T, Oketani M, Toyota J, Izumi N, Hiasa Y, Matsumoto A, Nomura H, Seike M, Ueno Y, Yotsuyanagi H, Kumada H. Factors predictive of sustained virological response following 72 weeks of combination therapy for genotype 1b hepatitis C. J Gastroenterol 2011; 46:545-555. [PMID: 21246384 DOI: 10.1007/s00535-010-0358-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Accepted: 11/25/2010] [Indexed: 02/04/2023]
Abstract
BACKGROUND Treatment of genotype 1b chronic hepatitis C virus (HCV) infection has been improved by extending peg-interferon plus ribavirin combination therapy to 72 weeks, but predictive factors are needed to identify those patients who are likely to respond to long-term therapy. METHODS We analyzed amino acid (aa) substitutions in the core protein and the interferon sensitivity determining region (ISDR) of nonstructural protein (NS) 5A in 840 genotype 1b chronic hepatitis C patients with high viral load. We used logistic regression and classification and regression tree (CART) analysis to identify predictive factors for sustained virological response (SVR) for patients undergoing 72 weeks of treatment. RESULTS When patients were separately analyzed by treatment duration using multivariate logistic regression, several factors, including sex, age, viral load, and core aa70 and ISDR substitutions (P = 0.0003, P = 0.02, P = 0.01, P = 0.0001, and P = 0.0004, respectively) were significant predictive factors for SVR with 48 weeks of treatment, whereas age, previous interferon treatment history, and ISDR substitutions (P = 0.03, P = 0.01, and P = 0.02, respectively) were the only significant predictive factors with 72 weeks of treatment. Using CART analysis, a decision tree was generated that identified age, cholesterol, sex, treatment length, and aa70 and ISDR substitutions as the most important predictive factors. The CART model had a sensitivity of 69.2% and specificity of 60%, with a positive predictive value of 68.4%. CONCLUSIONS Complementary statistical and data mining approaches were used to identify a subgroup of patients likely to benefit from 72 weeks of therapy.
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Affiliation(s)
- Kazuaki Chayama
- Department of Medical and Molecular Science, Division of Frontier Medical Science, Programs for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
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Chayama K, Hayes CN, Yoshioka K, Moriwaki H, Okanoue T, Sakisaka S, Takehara T, Oketani M, Toyota J, Izumi N, Hiasa Y, Matsumoto A, Nomura H, Seike M, Ueno Y, Yotsuyanagi H, Kumada H. Accumulation of refractory factors for pegylated interferon plus ribavirin therapy in older female patients with chronic hepatitis C. Hepatol Res 2010; 40:1155-1167. [PMID: 21040273 DOI: 10.1111/j.1872-034x.2010.00726.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
AIM Several host and viral factors have been reported to influence the effectiveness of pegylated interferon plus ribavirin combination therapy for chronic hepatitis C. In Japan, where the age of treated patients is comparatively high, recent studies have reported poor response to treatment in older female patients, but little is known about the relationship between advanced age in women and previously reported factors. METHODS Using a database of 1167 patients chronically infected with hepatitis C virus (HCV) genotype 1b, we analyzed the amino acid sequences of the HCV core protein and interferon sensitivity determining region (ISDR) and examined the relationships among predictive factors. RESULTS The proportion of patients with substitutions at core 70, which is associated with poor response to pegylated interferon plus ribavirin therapy, increased with age only in female patients. A similar trend was observed for ISDR wild type (wt). We also found that core 70 wt is associated with core 91 wt (P = 5.4 × 10(-9) ) as well as ISDR wt (P = 0.025). HCV RNA levels were higher in patients with core and ISDR wt (P < 0.001). Furthermore, core amino acid mutations were associated with advanced fibrosis and higher inflammatory activity (P = 0.028 and 0.048, respectively) as well as higher gamma-glutamyltranspeptidase, alanine aminotransferase and low-density lipoprotein cholesterol levels (P < 0.001, 0.006 and 0.001, respectively). CONCLUSION A combination of factors account for poor response rate in older female patients in Japan. Elucidating the relationship between amino acid substitutions and metabolic alteration is an important step in understanding the mechanism of HCV interferon resistance.
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Affiliation(s)
- Kazuaki Chayama
- Department of Medicine and Molecular Science, Division of Frontier Medical Science, Programs for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
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Yuan H, Jain M, Snow KK, Gale M, Lee WM, the HALT-C Trial Group. Evolution of hepatitis C virus NS5A region in breakthrough patients during pegylated interferon and ribavirin therapy*. J Viral Hepat 2010; 17:208-16. [PMID: 19656286 PMCID: PMC3189487 DOI: 10.1111/j.1365-2893.2009.01169.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Investigating the evolution of the hepatitis C viral (HCV) genome in the small number of patients that experience viral breakthrough might shed light on the problem of resistance to interferon therapy. Within the HCV genome, sequence diversity of the viral nonstructural 5A protein-coding region (NS5A) has been linked to interferon responsiveness. We analysed the temporal sequence changes within NS5A in genotype 1a patients: 6 breakthrough (BT), 12 sustained virologic responders (SVR) and 12 non-responders (NR), all of whom had received full dose peg-interferon and ribavirin therapy. The entire NS5A region was amplified by reverse transcription (RT)-PCR followed by direct sequencing of serum samples from baseline and three on-treatment time points for each group. Comparing baseline sequences with week 12 and later time points, BT patients resembled SVR patients in having a higher number of amino acid substitutions at week 12 than NR patients; however, the number of amino acid substitutions in this group decreased at and after BT. Substitutions were focused in the V3 and flanking regions in BT patients but not in SVR patients. The high number of substitutions in NS5A in both BT and SVR groups suggests that selective pressure is associated with viral response to therapy. Our results provide evidence that amino acid substitutions within the NS5A coding region may reflect a host response that drives selective pressure for viral adaptation.
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Affiliation(s)
- Hejun Yuan
- Divisions of Digestive and Liver Diseases and Infectious Diseases, UT Southwestern Medical Center at Dallas, Dallas, TX
| | - Mamta Jain
- Divisions of Digestive and Liver Diseases and Infectious Diseases, UT Southwestern Medical Center at Dallas, Dallas, TX
| | | | - Michael Gale
- Department of Immunology, University of Washington, Seattle, WA
| | - William M. Lee
- Divisions of Digestive and Liver Diseases and Infectious Diseases, UT Southwestern Medical Center at Dallas, Dallas, TX
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Viral factors influencing the response to the combination therapy of peginterferon plus ribavirin in chronic hepatitis C. J Gastroenterol 2009; 44:1009-15. [PMID: 19756352 DOI: 10.1007/s00535-009-0126-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Accepted: 08/13/2009] [Indexed: 02/04/2023]
Abstract
Hepatitis C virus (HCV) is a single-stranded RNA virus known for its high genetic variability owing to the lack of a proofreading mechanism of its RNA dependent RNA polymerase. Until now, numerous studies have been undertaken to clarify the correlation between pretreatment HCV genetic variability and the therapeutic response. Even with the recent combination therapy of peginterferon plus ribavirin for chronic hepatitis C, viral response is variable, and only half of treated patients could clear the virus [sustained viral response (SVR)]. In this review, the contribution of viral genetic variability affecting the treatment outcome is discussed according to each HCV genomic region.
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Argentini C, Genovese D, Dettori S, Rapicetta M. HCV genetic variability: from quasispecies evolution to genotype classification. Future Microbiol 2009; 4:359-73. [PMID: 19327119 DOI: 10.2217/fmb.09.8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
HCV is a ssRNA virus belonging to the Flaviviruses and is found worldwide worldwide in humans. Following primary infection, persistent infection develops in more than 85% of cases, which in up to 30% of cases, may progress to liver disease, cirrhosis and hepatocellular carcinoma. The virus presents a high degree of genetic variability owing to the combination of a lack of proofreading by the RNA-dependent RNA polymerase and a high level of viral replication. This genetic variability allows the classification of genotypes, subtypes, isolates and quasispecies to which epidemiological and pathogenetic significance may be associated. The features and biological implications of HCV variability and of quasispecies dynamics in infection transmission, mechanisms of chronicity and resistance to antiviral therapy are discussed.
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Affiliation(s)
- Claudio Argentini
- Viral Hepatitis Unit, Department of Infectious, Parasitic & Immune-Mediated Disease, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome, Italy.
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Bode JG, Brenndörfer ED, Häussinger D. Hepatitis C virus (HCV) employs multiple strategies to subvert the host innate antiviral response. Biol Chem 2009; 389:1283-98. [PMID: 18713016 DOI: 10.1515/bc.2008.147] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hepatitis C virus (HCV) is a serious global health problem which accounts for approximately 40% of chronic liver diseases worldwide. HCV frequently establishes a persistent infection, although it is recognized and targeted by innate immunity as well as cellular and humoral immune mechanisms. This suggests that HCV has developed powerful strategies to escape elimination by innate and adaptive immunity. HCV-induced liver injury is thought to be mainly immune-mediated rather than due to direct cytopathic effects of the virus. Hence, therapeutic strategies should target those mechanisms favoring viral persistence since unspecific enhancement of host antiviral immunity may theoretically also promote liver injury. The present review summarizes our current understanding of how the hepatitis C virus interferes with the innate antiviral host-response to establish persistent infection.
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Affiliation(s)
- Johannes G Bode
- Department of Gastroenterology, University Hospital, Heinrich Heine University Düsseldorf, D-40225 Düsseldorf, Germany.
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El-Shamy A, Nagano-Fujii M, Sasase N, Imoto S, Kim SR, Hotta H. Sequence variation in hepatitis C virus nonstructural protein 5A predicts clinical outcome of pegylated interferon/ribavirin combination therapy. Hepatology 2008; 48:38-47. [PMID: 18537193 DOI: 10.1002/hep.22339] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
UNLABELLED A substantial proportion of hepatitis C virus (HCV)-1b-infected patients still do not respond to interferon-based therapy. This study aims to explore a predictive marker for the ultimate virological response of HCV-1b-infected patients treated with pegylated interferon/ribavirin (PEG-IFN/RBV) combination therapy. Nonstructural protein 5A (NS5A) sequences of HCV in the pretreated sera of 45 patients infected with HCV-1b were analyzed. The mean number of mutations in the variable region 3 (V3) plus its upstream flanking region of NS5A (amino acid 2334-2379), referred to as IFN/RBV resistance-determining region (IRRDR), was significantly higher for HCV isolates obtained from patients who later achieved sustained virological response (SVR) by PEG-IFN/RBV than for those in patients undergoing non-SVR. The receiver operating characteristic curve analysis estimated six mutations in IRRDR as the optimal threshold for SVR prediction. Indeed, 16 (76%) of 21 SVR, but only 2 (8%) of 24 non-SVR, had HCV with six or more mutations in IRRDR (IRRDR > or = 6) (P < 0.0001). All of 18 patients infected with HCV of IRRDR of 6 or greater examined showed a significant (> or =1 log) reduction or disappearance of serum HCV core antigen titers within 24 hours after initial dose of PEG-IFN/RBV, whereas 10 (37%) of 27 patients with HCV of IRRDR of 5 or less did (P < 0.0001). The positive predictive value of IRRDR of 6 or greater for SVR was 89% (16/18; P = 0.0007), with its negative predictive value for non-SVR being 81% (22/27; P = 0.0008). CONCLUSION A high degree (> or =6) of sequence variation in IRRDR would be a useful marker for predicting SVR, whereas a less diverse (< or =5) IRRDR sequence predicts non-SVR.
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Affiliation(s)
- Ahmed El-Shamy
- Division of Microbiology, Kobe University Graduate School of Medicine, Kobe, Japan
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Cannon NA, Donlin MJ, Fan X, Aurora R, Tavis JE, for the Virahep-C Study Group. Hepatitis C virus diversity and evolution in the full open-reading frame during antiviral therapy. PLoS One 2008; 3:e2123. [PMID: 18463735 PMCID: PMC2373758 DOI: 10.1371/journal.pone.0002123] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Accepted: 03/19/2008] [Indexed: 12/19/2022] Open
Abstract
Background Pegylated interferon plus ribavirin therapy for hepatitis C virus (HCV) fails in approximately half of genotype 1 patients. Treatment failure occurs either by nonresponse (minimal declines in viral titer) or relapse (robust initial responses followed by rebounds of viral titers during or after therapy). HCV is highly variable genetically. To determine if viral genetic differences contribute to the difference between response and relapse, we examined the inter-patient genetic diversity and mutation pattern in the full open reading frame HCV genotype 1a consensus sequences. Methodology/Principal Findings Pre- and post-therapy sequences were analyzed for 10 nonresponders and 10 relapsers from the Virahep-C clinical study. Pre-therapy interpatient diversity among the relapsers was higher than in the nonresponders in the viral NS2 and NS3 genes, and post-therapy diversity was higher in the relapsers for most of HCV's ten genes. Pre-therapy diversity among the relapsers was intermediate between that of the non-responders and responders to therapy. The average mutation rate was just 0.9% at the amino acid level and similar numbers of mutations occurred in the nonresponder and relapser sequences, but the mutations in NS2 of relapsers were less conservative than in nonresponders. Finally, the number and distribution of regions under positive selection was similar between the two groups, although the nonresponders had more foci of positive selection in E2. Conclusions/Significance The HCV sequences were unexpectedly stable during failed antiviral therapy, both nonresponder and relapser sequences were under selective pressure during therapy, and variation in NS2 may have contributed to the difference in response between the nonresponder and relapser groups. These data support a role for viral genetic variability in determining the outcome of anti-HCV therapy, with those sequences that are more distant from an optimal sequence being less able to resist the pressures of interferon-based therapy. Trial registration ClinicalTrials.gov NCT00038974
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Affiliation(s)
- Nathan A. Cannon
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Maureen J. Donlin
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Xiaofeng Fan
- Department of Internal Medicine, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Rajeev Aurora
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - John E. Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
- Saint Louis University Liver Center, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
- * E-mail:
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Kumar D, Malik A, Asim M, Chakravarti A, Das RH, Kar P. Influence of quasispecies on virological responses and disease severity in patients with chronic hepatitis C. World J Gastroenterol 2008; 14:701-8. [PMID: 18205258 PMCID: PMC2683995 DOI: 10.3748/wjg.14.701] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To elucidate the influence of quasispecies on virological response and disease severity in patients with chronic hepatitis C.
METHODS: Forty seven patients with hepatitis C [32 with chronic active hepatitis (CAH), 9 with cirrhosis, and 6 with hepatocellular carcinoma (HCC)] were screened for the presence of quasispecies by single stranded conformational polymorphism (SSCP) analysis in the hypervariable region (HVR) and non-structural 5B (NS5B) viral genes of hepatitis C virus. The 41 patients excluding those with HCC were on therapy and followed up for a year with the determination of virological response and disease severity. Virus isolated from twenty three randomly selected patients (11 non-responders and 12 showing a sustained virological response) was sequenced for the assessment of mutations.
RESULTS: The occurrence of quasispecies was proportionately higher in patients with HCC and cirrhosis than in those with CAH, revealing a significant correlation between the molecular evolution of quasispecies and the severity of disease in patients with hepatitis C. The occurrence of complex quasispecies has a significant association (P < 0.05) with the non-responders, and leads to persistence of infection. Significant differences (P < 0.05) in viral load (log10 IU/mL) were observed among patients infected with complex quasispecies (CQS), those infected with simple quasispecies (SQS) and those with no quasispecies (NQS), after 12 wk (CQS-5.2 ± 2.3, SQS-3.2 ± 1.9, NQS-2.8 ± 2.4) and 24 wk (CQS-3.9 ± 2.2, SQS-3.0 ± 2.2, NQS-2.1 ± 2.3) in the HVR region. However, a statistically significant difference (P < 0.05) was observed between the viral loads of patients infected with CQS and those infected with NQS in NS5B viral gene after 24 wk (CQS-3.9 ± 2.2, SQS-3.0 ± 2.2, and NQS-2.1 ± 2.3) and 48 wk (CQS-3.1 ± 2.7, SQS-2.3 ± 2.4, NQS-2.0 ± 2.3) of therapy. Disease severity was significantly associated with viral load during therapy. The strains isolated from non-responders showed close pairing on phylogeny based on the NS5B gene, but dissimilar HVR regions. This revealed the possibility of the selection of resistant strains during the evolution of quasispecies in NS5B.
CONCLUSION: Viral quasispecies may be an important predictor of virological responses to combination therapy in patients with chronic hepatitis C. Complex quasispecies and resistant strains may lead to high viral loads during therapy, with a concerted effect on disease severity.
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El-Shamy A, Sasayama M, Nagano-Fujii M, Sasase N, Imoto S, Kim SR, Hotta H. Prediction of efficient virological response to pegylated interferon/ribavirin combination therapy by NS5A sequences of hepatitis C virus and anti-NS5A antibodies in pre-treatment sera. Microbiol Immunol 2008; 51:471-82. [PMID: 17446688 DOI: 10.1111/j.1348-0421.2007.tb03922.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A considerable number of patients infected with Hepatitis C virus subtype 1b (HCV-1b) do not respond to pegylated interferon/ribavirin combination therapy. In this study we explored a useful factor(s) to predict treatment outcome. A total of 47 HCV-1b-infected patients were treated with pegylated interferon/ ribavirin for 48 weeks. Sera of the patients were examined for the entire NS5A sequence of the HCV genome, HCV RNA titers and anti-NS5A antibodies. According to their responses, the patients were divided into two groups, early viral responders who cleared the virus by week 16 (EVR[16w]) and those who did not (Non-EVR[16w]). The mean number of mutations in the V3 region (aa 2356 to 2379) or that in the V3 region plus its N-terminally flanking region, which we refer to as interferon/ribavirin resistancedetermining region (IRRDR; aa 2334 to 2379), of NS5A obtained from the pretreatment sera was signifi-cantly larger for EVR(16w) compared with Non-EVR(16w). Moreover, HCV-1b isolates with > or =5 mutations in V3 or those with > or =6 mutations in IRRDR were almost exclusively found in EVR(16w). Also, the presence of detectable levels of anti-NS5A antibodies in the pretreatment sera was closely associated with EVR(16w). In conclusion, a high degree of sequence variation in V3 (> or =5) or IRRDR (> or =6) and the presence of detectable levels of anti-NS5A antibodies in the pretreatment sera would be useful factors to predict EVR(16w). On the other hand, a less diverse sequence in V3 (< or =4) or IRRDR (< or =5) together with the absence of detectable anti-NS5A antibodies could be a predictive factor for Non-EVR(16w).
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Affiliation(s)
- Ahmed El-Shamy
- Division of Microbiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
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Yoon J, Lee JI, Baik SK, Lee KH, Sohn JH, Lee HW, Namkung J, Chang SJ, Choi JW, Kim HW, Yeh BI. Predictive factors for interferon and ribavirin combination therapy in patients with chronic hepatitis C. World J Gastroenterol 2007; 13:6236-42. [PMID: 18069766 PMCID: PMC4171236 DOI: 10.3748/wjg.v13.i46.6236] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To confirm the predictive factors for interferon (IFN)-α and ribavirin combination therapy for chronic hepatitis patients with hepatitis C virus (HCV) genotype 1b.
METHODS: HCV RNA from 50 patients infected with HCV genotype 1b was studied by cloning and sequencing of interferon sensitivity determining region (ISDR), PKR-eIF2α phosphorylation homology domain (PePHD). Patients were treated with IFN-α and ribavirin for 6 mo and grouped by effectiveness of the therapy. A variety of factors were analyzed.
RESULTS: Our data showed that age, HCV RNA titer, and ISDR type could be used as the predictive factors for combined IFN-α and ribavirin efficacy. Characteristically, mutations in PePHD appeared only when the combination therapy was effective. Other factors, such as sex and alanine aminotransferase (ALT) level, were not related to its efficacy. Adjusting for age and HCV RNA titer indicated that the ISDR type was the most potent predictive factor.
CONCLUSION: HCV RNA ISDR type is an important factor for predicting efficacy of IFN-α and ribavirin combination therapy in Korean patients.
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Thélu MA, Leroy V, Ramzan M, Dufeu-Duchesne T, Marche P, Zarski JP. IRES complexity before IFN-alpha treatment and evolution of the viral load at the early stage of treatment in peripheral blood mononuclear cells from chronic hepatitis C patients. J Med Virol 2007; 79:242-53. [PMID: 17245718 DOI: 10.1002/jmv.20792] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
At the early stage of treatment, IFN alpha-2a induces inhibition of HCV replication. The viral load reflects mainly the degradation rate of the viruses. However, differences in the behavior of the viral population depend on changes, which occurred in the HCV-IRES genome. In this study, cloning and sequencing strategies permitted the generation of a large number of IRES sequences from the PBMCs of 18 patients (5 women, 13 men) with chronic hepatitis C. The HCV IRES appeared to be highly conserved structurally. However, some variability was found between the different isolates obtained: 467 substitutions with a median of 7 variants/patients. No relationship was observed between pre-treatment IRES complexity and the viral load at the beginning. However, on review of the evolution of viral load in the PBMCs during the first 3 days of IFN alpha-2a treatment, patients could be classified into two groups: Group 1, in which the viral population continued to replicate and Group 2, in which the viral load decreased significantly (P = 0.01727). Positioning of the mutations on the predicted IRES secondary structure showed that the distribution of the mutations and their apparition frequency were different between the two groups. At the early stage of treatment, IFN alpha-2a was efficient in reducing the viral replication in a significant number of patients; mechanisms of response might affect the virus directly. However, pre-treatment genomic variations observed in the 5'NCR of HCV were not a parameter of a later response to antiviral therapy in chronic hepatitis C patients. (244)
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Affiliation(s)
- M A Thélu
- Département d'Hépato-Gastroentérologie, Hôpital Albert Michallon, Grenoble, France
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21
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Donlin MJ, Cannon NA, Yao E, Li J, Wahed A, Taylor MW, Belle SH, Di Bisceglie AM, Aurora R, Tavis JE. Pretreatment sequence diversity differences in the full-length hepatitis C virus open reading frame correlate with early response to therapy. J Virol 2007; 81:8211-24. [PMID: 17522222 PMCID: PMC1951276 DOI: 10.1128/jvi.00487-07] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Pegylated alpha interferon and ribavirin therapy for hepatitis C virus (HCV) genotype 1 infection fails for half of Caucasian American patients (CA) and more often for African Americans (AA). The reasons for these low response rates are unknown. HCV is highly genetically variable, but it is unknown how this variability affects response to therapy. To assess effects of viral diversity on response to therapy, the complete pretreatment genotype 1 HCV open reading frame was sequenced using samples from 94 participants in the Virahep-C study. Sequences from patients with >3.5 log declines in viral RNA levels by day 28 (marked responders) were more variable than those from patients with declines of <1.4 log (poor responders) in NS3 and NS5A for genotype 1a and in core and NS3 for genotype 1b. These correlations remained when all T-cell epitopes were excluded, indicating that these differences were not due to differential immune selection. When the sequences were compared by race of the patients, higher diversity in CA patients was found in E2 and NS2 but only for genotype 1b. Core, NS3, and NS5A can block the action of alpha interferon in vitro; hence, these genetic patterns are consistent with multiple amino acid variations independently impairing the function of HCV proteins that counteract interferon responses in humans, resulting in HCV strains with variable sensitivity to therapy. No evidence was found for novel HCV strains in the AA population, implying that AA patients may be infected with a higher proportion of the same resistant strains that are found in CA patients.
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Affiliation(s)
- Maureen J Donlin
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1402 S. Grand Blvd., Saint Louis, MO 63104, USA
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22
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Le Guillou-Guillemette H, Vallet S, Gaudy-Graffin C, Payan C, Pivert A, Goudeau A, Lunel-Fabiani F. Genetic diversity of the hepatitis C virus: Impact and issues in the antiviral therapy. World J Gastroenterol 2007; 13:2416-26. [PMID: 17552024 PMCID: PMC4146759 DOI: 10.3748/wjg.v13.i17.2416] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The hepatitis C Virus (HCV) presents a high degree of genetic variability which is explained by the combination of a lack of proof reading by the RNA dependant RNA polymerase and a high level of viral replication. The resulting genetic polymorphism defines a classification in clades, genotypes, subtypes, isolates and quasispecies. This diversity is known to reflect the range of responses to Interferon therapy. The genotype is one of the predictive parameters currently used to define the antiviral treatment strategy and the chance of therapeutic success. Studies have also reported the potential impact of the viral genetic polymorphism in the outcome of antiviral therapy in patients infected by the same HCV genotype. Both structural and non structural genomic regions of HCV have been suggested to be involved in the Interferon pathway and the resistance to antiviral therapy. In this review, we first detail the viral basis of HCV diversity. Then, the HCV genetic regions that may be implicated in resistance to therapy are described, with a focus on the structural region encoded by the E2 gene and the non-structural genes NS3, NS5A and NS5B. Both mechanisms of the Interferon resistance and of the new antiviral drugs are described in this review.
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Affiliation(s)
- H Le Guillou-Guillemette
- Laboratory of Virology, Department of Infectious Agents, University Hospital of Angers, 4 rue Larrey, 49933 Angers Cedex 9, France
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Welker MW, Hofmann WP, Welsch C, von Wagner M, Herrmann E, Lengauer T, Zeuzem S, Sarrazin C. Correlation of amino acid variations within nonstructural 4B protein with initial viral kinetics during interferon-alpha-based therapy in HCV-1b-infected patients. J Viral Hepat 2007; 14:338-49. [PMID: 17439523 DOI: 10.1111/j.1365-2893.2006.00798.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Chronic hepatitis C is a major cause of liver cirrhosis leading to chronic liver failure and hepatocellular carcinoma. Different hepatitis C virus (HCV) proteins have been associated with resistance to interferon-alpha-based therapy. However, the exact mechanisms of virus-mediated interferon resistance are not completely understood. The importance of amino acid (aa) variations within the HCV nonstructural (NS)4B protein for replication efficiency and viral decline during the therapy is unknown. We investigated pretreatment sera from 42 patients with known outcome to interferon-based therapy. The complete NS4B gene was amplified and sequenced. Mutational analyses of predicted conformational, functional, structural and phylogenetic properties of the deduced aa sequences were performed. The complete NS4B protein was highly conserved with a median frequency of 0.015 +/- 0.009 aa exchanges (median +/- SD, 4.00 +/- 2.31). Especially within the predicted transmembranous domains of the NS4B protein, the mean number of aa variations was low (median frequency, 0.013 +/- 0.013). Neither the number of aa variations nor specific aa exchanges were correlated with HCV RNA serum concentration at baseline. A rapid initial HCV RNA decline of >/=1.5 log(10) IU/mL at week 2 of interferon-based therapy was associated with a higher frequency of nonconservative aa exchanges within the complete NS4B protein in comparison with patients with a nonrapid HCV RNA decline (median frequency, 0.011 +/- 0.005 vs 0.004 +/- 0.003, P = 0.006). Overall, the aa sequence of the NS4B protein was highly conserved, indicating an important role for replication in vivo. Amino acid variations with relevant changes of physicochemical properties may influence replication efficiency, associated with a rapid early virological response.
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Affiliation(s)
- M-W Welker
- Klinik für Innere Medizin II, Universitätsklinikum des Saarlandes, Homburg/Saar, Germany
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24
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Zekri ARN, El-Din HMA, Bahnassy AA, Khaled MM, Omar A, Fouad I, El-Hefnewi M, Thakeb F, El-Awady M. Genetic distance and heterogenecity between quasispecies is a critical predictor to IFN response in Egyptian patients with HCV genotype-4. Virol J 2007; 4:16. [PMID: 17300723 PMCID: PMC1805740 DOI: 10.1186/1743-422x-4-16] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2006] [Accepted: 02/14/2007] [Indexed: 02/05/2023] Open
Abstract
Background HCV is one of the major health problems in Egypt, where it is highly prevalent. Genotype 4 is the most common genotype of HCV and its response to treatment is still a controversy. Methods HCV genotype 4 quasispecies diversity within the 5' untranslated region (5'UTR) was studied in a series of 22 native Egyptian patients with chronic hepatitis C virus with no previous treatment who satisfied all NIH criteria for combined treatment of pegylated IFN and ribavirine and was correlated with the outcome of treatment. The study also included 7 control patients with no antiviral treatment. HCV sequencing was done using the TRUGENE HCV 5-NC genotyping kit. Results At the 48th week of treatment, 15 patients (68%) showed virological response. Whereas HCV-RNA was still detected in 7 patients (32%) in this period; of those, 6 experienced a partial virological response followed by viral breakthrough during treatment. Only one patient did not show any virological or chemical response. The four females included in this study were all responders. There was a significant correlation between the response rate and lower fibrosis (p = 0.026) as well as the total number of mutation spots (including all the insertions, deletions, transitions and transversions) (p = 0.007, p = 0.035). Conclusion Patients who responded to interferon treatment had statistically significant less number in both transitions (p = 0.007) and the genetic distances between the quasispecies (p = 0.035). So, viral genetic complexity and variability may play a role in the response to IFN treatment. The consensus alignment of all three groups revealed no characteristic pattern among the three groups. However, the G to A transitions at 160 was observed among non responders who need further study to confirm this observation.
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Affiliation(s)
- Abdel Rahman N Zekri
- Virology and Immunology Unit, Cancer Biology Department, National Cancer Institute, Cairo University.1Kasr El-Aini st, Cairo, Egypt
| | - Hanaa M Alam El-Din
- Virology and Immunology Unit, Cancer Biology Department, National Cancer Institute, Cairo University.1Kasr El-Aini st, Cairo, Egypt
| | - Abeer A Bahnassy
- Pathology Department, National Cancer Institute, Cairo University 1Kasr El-Aini st., Cairo, Egypt
| | - Mohsen M Khaled
- National Diabetes Institute, Ministry of Health, Egypt, Kasr El-Aini st., Cairo, Egypt
| | - Ashraf Omar
- Kasr El-Aini School of Medicine, Cairo University, Kasr El-Aini st., Cairo, Egypt
| | - Inas Fouad
- Kasr El-Aini School of Medicine, Cairo University, Kasr El-Aini st., Cairo, Egypt
| | | | - Fouad Thakeb
- Kasr El-Aini School of Medicine, Cairo University, Kasr El-Aini st., Cairo, Egypt
| | - Mostafa El-Awady
- National Research Center, Cairo, Egypt, Tahrir St., Cairo, Egypt
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Maynard M, Pradat P, Bailly F, Rozier F, Nemoz C, Si Ahmed SN, Adeleine P, Trépo C. Amantadine triple therapy for non-responder hepatitis C patients. Clues for controversies (ANRS HC 03 BITRI). J Hepatol 2006; 44:484-90. [PMID: 16426697 DOI: 10.1016/j.jhep.2005.11.038] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2005] [Revised: 10/17/2005] [Accepted: 11/04/2005] [Indexed: 02/06/2023]
Abstract
BACKGROUND/AIMS To determine whether addition of amantadine to pegylated interferon/ribavirin improved response rates among chronic hepatitis C patients, non-responders to interferon/ribavirin and study the dynamic of response. METHODS In a double blind, multicenter, randomized trial, 200 non-responder patients received pegylated interferon 1.5 microg/kg per week and ribavirin 800-1200 mg/day, plus either amantadine 200 mg/day or placebo for 48 weeks. Endpoints were virological responses, ALT normalization, and histological benefit overtime. RESULTS Twenty percent of all patients achieved a sustained virological response (SVR). This rate was 8% higher in the triple therapy group (24%) compared with the double therapy group (16%) (P = 0.22). A better virological response rate at week 24 was observed in the triple regimen group (43 vs 29%; P = 0.06), which was lost at week 48 suggesting viral escape. The biochemical response rate was also significantly higher with triple therapy at week 12 (63 vs 49%; P = 0.05) and week 24 (64 vs 49%; P = 0.03). Fibrosis stabilized or improved in 77% of all patients. CONCLUSIONS Re-treatment of interferon/ribavirin non-responder patients should be encouraged since a substantial proportion benefits from re-treatment with pegylated interferon/ribavirin +/- amantadine. In triple therapy involving amantadine, a time wise response and an increased SVR rate in subgroups less prone to viral breakthrough suggest clues for existing controversies.
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Affiliation(s)
- Marianne Maynard
- Department of Hepato-gastroenterology, Hôtel-Dieu, 1 place de l'Hôpital, 69288 Lyon Cedex 02, France
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Khattab E, Chemin I, Vuillermoz I, Vieux C, Mrani S, Guillaud O, Trepo C, Zoulim F. Analysis of HCV co-infection with occult hepatitis B virus in patients undergoing IFN therapy. J Clin Virol 2004; 33:150-7. [PMID: 15911431 DOI: 10.1016/j.jcv.2004.10.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2004] [Revised: 10/08/2004] [Accepted: 10/28/2004] [Indexed: 12/15/2022]
Abstract
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.
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MESH Headings
- Adult
- Amantadine/therapeutic use
- Amino Acid Sequence
- Antiviral Agents/therapeutic use
- DNA, Viral/blood
- DNA, Viral/chemistry
- Drug Resistance, Viral
- Female
- France
- Hepacivirus/genetics
- Hepacivirus/isolation & purification
- Hepatitis B virus/genetics
- Hepatitis B virus/isolation & purification
- Hepatitis B, Chronic/complications
- Hepatitis B, Chronic/drug therapy
- Hepatitis C, Chronic/complications
- Hepatitis C, Chronic/drug therapy
- Humans
- Interferon alpha-2
- Interferon-alpha/therapeutic use
- Male
- Middle Aged
- Molecular Sequence Data
- Polymerase Chain Reaction
- RNA, Viral/blood
- RNA, Viral/chemistry
- Recombinant Proteins
- Ribavirin/therapeutic use
- Sequence Alignment
- Sequence Analysis, DNA
- Viral Load
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Affiliation(s)
- E Khattab
- INSERM UNIT 271, 151 cours Albert Thomas, 69424 Lyon Cedex 03, France
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