RESUMEN
In a hepatitis C virus (HCV)-controlled human infection model (CHIM), healthy volunteers are inoculated with HCV and then treated. Residual hepatocellular carcinoma (HCC) risk after viral clearance is an important consideration when evaluating the CHIM. We estimate HCC risk in spontaneously cleared HCV and in noncirrhosis after sustained virological response (SVR) to HCV treatment in a systematic review and using data from 3 cohorts: German anti-D, Taiwan, and US Veterans Affairs (VA). For noncirrhosis SVR, the overall HCC rate is 0.33 per 100 patient-years in meta-analysis. HCC rates for the German, Taiwan, and US Veterans Affairs cohorts are 0, 0.14, and 0.02 per 100 patient-years, respectively. Past hepatitis B virus exposure was not accounted for in the Taiwan cohort, while VA patients were likely tested based on liver disease/risk factors, which may confound HCC outcomes. The German cohort with no HCC after 44 years is most comparable to the CHIM participants. Although it is difficult to precisely estimate HCC risk from an HCV CHIM, the data suggest the risk to be very low or negligible.
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Carcinoma Hepatocelular , Hepatitis C Crónica , Hepatitis C , Neoplasias Hepáticas , Humanos , Antivirales/uso terapéutico , Carcinoma Hepatocelular/epidemiología , Hepacivirus , Hepatitis C/complicaciones , Hepatitis C/tratamiento farmacológico , Hepatitis C/epidemiología , Hepatitis C Crónica/complicaciones , Hepatitis C Crónica/tratamiento farmacológico , Neoplasias Hepáticas/epidemiología , Respuesta Virológica SostenidaRESUMEN
OBJECTIVE: As pathogen sensors, Toll-like receptors (TLR) play a role in the first defence line during HCV infection. However, the impact of the DNA sensor TLR9 on the natural course of HCV infection is unknown. To address this, TLR9 promoter polymorphisms (single nucleotide polymorphisms (SNPs)) rs187084 and rs5743836 were investigated for their effect on disease progression. DESIGN: Therefore, the TLR9 SNPs and the interferon lambda 4 (IFNL4) rs12979860 were genotyped in chronically HCV type 1 infected (n=333), in patients who spontaneously cleared the infection (n=161), in the Swiss HCV cohort (n=1057) and the well-characterised German (n=305) and Irish (n=198) 'anti-D' cohorts. Functional analyses were done with promoter reporter constructs of human TLR9 in B cells and assessing TLR9 mRNA levels in whole blood of healthy volunteers. RESULTS: The TLR9 rs187084 C allele was associated with spontaneous virus clearance in women of the study cohort (OR=2.15 (95% CI 1.18 to 3.90) p=0.012), of the Swiss HCV cohort (OR=2.06 (95% CI 1.02 to 4.18) p=0.044) and in both 'anti-D' cohorts (German: OR=2.01 (95% CI 1.14 to 3.55) p=0.016; Irish: OR=1.93 (95% CI 1.10 to 3.68) p=0.047). Multivariate analysis in the combined study and Swiss HCV cohorts supported the results (OR=1.99 (95% CI 1.30 to 3.05) p=0.002). Functional analyses revealed higher transcriptional activities for both TLR9 variants and an association of the C allele of rs5743836 with allele-specific TLR9 mRNA regulation by oestrogens in women. CONCLUSIONS: TLR9 promoter SNPs are associated with the natural course of HCV infection and show higher transcriptional activities. Our results imply the DNA sensor TLR9 in natural immunity against the RNA virus, HCV.
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Hepatitis C Crónica/genética , Interleucinas/genética , ARN Mensajero/sangre , Receptor Toll-Like 9/genética , Adulto , Anciano , Alelos , Progresión de la Enfermedad , Femenino , Regulación de la Expresión Génica/genética , Alemania , Haplotipos , Humanos , Irlanda , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Regiones Promotoras Genéticas , Remisión Espontánea , Estudios Retrospectivos , Factores Sexuales , Suiza , Transcripción GenéticaRESUMEN
UNLABELLED: Patients carrying very rare loss-of-function mutations in interleukin-1 receptor-associated kinase 4 (IRAK4), a critical signaling mediator in Toll-like receptor signaling, are severely immunodeficient, highlighting the paramount role of IRAK kinases in innate immunity. We discovered a comparatively frequent coding variant of the enigmatic human IRAK2, L392V (rs3844283), which is found homozygously in â¼15% of Caucasians, to be associated with a reduced ability to induce interferon-alpha in primary human plasmacytoid dendritic cells in response to hepatitis C virus (HCV). Cytokine production in response to purified Toll-like receptor agonists was also impaired. Additionally, rs3844283 was epidemiologically associated with a chronic course of HCV infection in two independent HCV cohorts and emerged as an independent predictor of chronic HCV disease. Mechanistically, IRAK2 L392V showed intact binding to, but impaired ubiquitination of, tumor necrosis factor receptor-associated factor 6, a vital step in signal transduction. CONCLUSION: Our study highlights IRAK2 and its genetic variants as critical factors and potentially novel biomarkers for human antiviral innate immunity.
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Hepatitis C Crónica/inmunología , Quinasas Asociadas a Receptores de Interleucina-1/genética , Genotipo , Células HEK293 , Humanos , Interferón-alfa/biosíntesis , Interferones , Quinasas Asociadas a Receptores de Interleucina-1/fisiología , Interleucinas/genética , Polimorfismo de Nucleótido Simple , Factor 6 Asociado a Receptor de TNF/metabolismo , Receptores Toll-Like/fisiología , UbiquitinaciónRESUMEN
BACKGROUND AND AIMS: Multiple clinical trials have demonstrated the efficacy and safety of tenofovir disoproxil fumarate (TDF) in chronic hepatitis B (CHB). However, long-term efficacy and safety data for TDF in real-life clinical practice are limited. METHODS: Prospective German field practice study in CHB-mono-infected patients. Patients were TDF-naïve but could have been treated previously with other HBV antivirals. RESULTS: Efficacy analysis included 400 patients; 301 (75 %) completed 36 months of TDF treatment. Both treatment-naïve and treatment-experienced patients showed a rapid decline in HBV DNA within 3 months of TDF initiation. After 36 months, HBV DNA < 69 IU/mL was achieved by 91 % of treatment-naïve patients (90 and 92 % in hepatitis B "e" antigen [HBeAg]-positive and [HBeAg]-negative, respectively) and 96 % of treatment-experienced patients (93 and 97 %, respectively). Three patients experienced virologic breakthrough, all with reported non-compliance. Overall, 5.7 % HBeAg-positive and 2.2 % HBeAg-negative patients lost hepatitis B surface antigen. Safety data were consistent with the known TDF safety profile; the most commonly reported adverse events possibly related to TDF were fatigue (2.0 %) and headache (2.0 %). Few patients (1.3 %) experienced renal-related adverse reactions. Creatinine clearance remained relatively stable over time; patients responded favorably where TDF was dose adjusted per label for decreased creatinine clearance. CONCLUSIONS: TDF showed a favorable tolerability profile and induced rapid and sustained suppression of HBV DNA in patients with CHB treated for up to 3 years in routine clinical practice, irrespective of treatment history. Efficacy and safety in this heterogeneous patient population were consistent with data from clinical trials.
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Antivirales/uso terapéutico , Hepatitis B Crónica/tratamiento farmacológico , Tenofovir/uso terapéutico , Adulto , Creatinina/sangre , ADN Viral/sangre , Diagnóstico por Imagen de Elasticidad , Fatiga/inducido químicamente , Femenino , Alemania , Cefalea/inducido químicamente , Antígenos de Superficie de la Hepatitis B/sangre , Antígenos e de la Hepatitis B/sangre , Hepatitis B Crónica/sangre , Hepatitis B Crónica/complicaciones , Hepatitis B Crónica/diagnóstico por imagen , Humanos , Enfermedades Renales/sangre , Enfermedades Renales/inducido químicamente , Hígado/diagnóstico por imagen , Cirrosis Hepática/diagnóstico por imagen , Cirrosis Hepática/etiología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Resultado del Tratamiento , Carga ViralRESUMEN
UNLABELLED: The natural course of HCV infection remains controversial. The German HCV (1b)-contaminated anti-D cohort provides an ideal population to investigate the natural course of HCV infection in a large, homogenous cohort of young women from the date of HCV inoculation. Our previous follow-up studies at 20 and 25 years after infection suggested slow fibrosis progression rates in this unique cohort. The aim of our prospective, community-based, multicenter study was to reevaluate the liver disease progression in 718 patients of the original anti-D cohort at 35 years after infection. Patients with self-limited HCV infection (n = 189) were compared to those who failed to eliminate the virus spontaneously (n = 529), comprising patients who were treatment naïve (n = 197) or achieved a sustained virological response (SVR; n = 149), respectively, failed to clear the virus (non-SVR; n = 183) after antiviral therapy. In the overall cohort, 9.3% of patients showed clinical signs of liver cirrhosis at 35 years after infection. Liver disease progression largely depended on HCV infection status. The highest proportion of patients with clinical signs of end-stage liver disease was observed in the non-SVR group (15.3%), whereas decreased cirrhosis rates were detected in the SVR group (6%) and in patients with self-limited HCV infection (1.1%; P = 6.2 × 10(-6)). Overall survival was significantly enhanced after SVR, compared to treatment-naïve patients or non-SVR (P = 0.027). CONCLUSION: The present study provides further evidence for a mild, but significant, disease progression at 35 years after infection in the German HCV (1b)-contaminated anti-D cohort. Patients with self-limited HCV infection or SVR after antiviral treatment were protected from progressive liver disease and showed the best clinical long-term outcome.
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Hepatitis C/epidemiología , Adolescente , Adulto , Anciano , Antivirales/uso terapéutico , Progresión de la Enfermedad , Contaminación de Medicamentos , Femenino , Estudios de Seguimiento , Alemania/epidemiología , Hepatitis C/tratamiento farmacológico , Hepatitis C/etiología , Humanos , Enfermedad Iatrogénica/epidemiología , Isoanticuerpos , Cirrosis Hepática/epidemiología , Cirrosis Hepática/etiología , Persona de Mediana Edad , Estudios Prospectivos , Globulina Inmune rho(D) , Análisis de Supervivencia , Adulto JovenRESUMEN
BACKGROUND: No information is available on the possible influence of the genetic heterogeneity of major hepatitis C virus (HCV) cell receptors on selection of virus variants. FINDINGS: Anti-D globulin preparations contaminated with the HCV strain AD78 caused hepatitis C infection in more than 3000 women in East Germany in 1978. Analysis of the core to NS2 gene sequences of this strain in several globulin batches revealed the presence of three closely related but distinct virus variants of the same strain. Apparently even distribution of these three virus variants was observed in 91 patients infected with the AD78 strain. None of these patients was infected with more than one virus variant, suggesting a selection mechanism of a particular virus variant in each patient. To verify the hypothesis that heterogeneity of HCV cell receptors might influence the virus variant selection, single-nucleotide polymorphisms (SNPs) in low-density lipoprotein receptor (LDLR), occludin (OCLN), and scavenger receptor B1 (SCARB1) genes in AD patients were analyzed. No evident correlation between receptor polymorphisms and presence of a particular virus variant was noted. CONCLUSION: SNPs of HCV cell entry receptors have no influence on virus selection in patients infected with an inoculum containing different virus variants.
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Heterogeneidad Genética , Hepacivirus/fisiología , Receptores Virales/genética , Internalización del Virus , Femenino , Alemania Oriental , Humanos , Ocludina/genética , Polimorfismo de Nucleótido Simple , Receptores de LDL/genética , Receptores Depuradores de Clase B/genética , Selección GenéticaRESUMEN
BACKGROUND & AIMS: The antiviral immune response against HCV by CD8+ T cells plays a central role in viral containment. In a large HCV genotype 1b outbreak in Ireland, HLA-B(∗)08 was identified as a risk allele for chronic infection and HLA-A(∗)03 and HLA-B(∗)27 were associated with higher clearance rates. Here we took advantage of a similar large common source HCV genotype 1b outbreak (East-German cohort) to determine the role of HLA class I alleles and the sequence of the infection source, in immunodominant CD8+ T cell epitopes for disease outcome. METHODS: HLA-type and IL28B genotype were determined in 216 patients with chronic and 95 with spontaneously resolved HCV infection. The viral sequence in immunodominant epitopes was determined in the infection source and in patients with chronic infection. RESULTS: In contrast to the Irish cohort, HLA-B(∗)08, HLA-A(∗)03 and HLA-B(∗)27 were neutral for disease outcome even when the cohort was stratified for the IL28B genotype. Sequence analysis of the immunodominant epitopes revealed that pre-existing substitutions in the infection source of both cohorts influenced the impact of the corresponding HLA-allele. The immunodominant epitopes presented by the "protective" alleles HLA-A(∗)03 and -B(∗)27 in the Irish cohort contained substitutions in the source virus of the East-German outbreak. Importantly, the pre-existing substitutions altered subsequent selection pressure and viral evolution in the East-German cohort. CONCLUSIONS: This study highlights that subtle sequence differences in the infection source may have profound effects on the ability to clear HCV infection in the presence of particular HLA class I alleles.
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Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/virología , Antígeno HLA-A3/genética , Antígeno HLA-B27/genética , Hepatitis C Crónica/epidemiología , Hepatitis C Crónica/inmunología , Brotes de Enfermedades/estadística & datos numéricos , Susceptibilidad a Enfermedades/epidemiología , Susceptibilidad a Enfermedades/inmunología , Epítopos de Linfocito T/inmunología , Genotipo , Alemania/epidemiología , Antígenos HLA-B/genética , Antígeno HLA-B8/genética , Humanos , Epítopos Inmunodominantes/inmunología , Irlanda/epidemiología , Factores de RiesgoRESUMEN
BACKGROUND & AIMS: Hepatitis C virus (HCV) acquires mutations that allow it to escape the CD8+ T-cell response, although the extent to which this process contributes to viral evolution at the population level is not clear. We studied viral adaptation using data from a large outbreak of HCV genotype 1b infection that occurred among women immunized with contaminated immunoglobulin from 1977 to 1978. METHODS: The HCV nonstructural protein coding regions NS3-NS5B were sequenced from 78 patients, and mutations were mapped according to their location inside or outside previously described CD8+ T-cell epitopes. A statistical approach was developed to identify sites/regions under reproducible selection pressure associated with HLA class I. RESULTS: The frequency of nonsynonymous mutations was significantly higher inside previously described CD8+ T-cell epitopes than outside-particularly in NS3/4A and NS5B. We identified new regions that are under selection pressure, indicating that not all CD8+ T-cell epitopes have been identified; 6 new epitopes that interact with CD8+ T cells were identified and confirmed in vitro. In some CD8+ T-cell epitopes mutations were reproducibly identified in patients that shared the relevant HLA allele, indicating immune pressure at the population level. There was statistical support for selection of mutations in 18 individual epitopes. Interestingly, 14 of these were restricted by HLA-B allele. CONCLUSIONS: HLA class I-associated selection pressure on the nonstructural proteins and here predominantly on NS3/4A and NS5B promotes evolution of HCV. HLA-B alleles have a dominant effect in this selection process. Adaptation of HCV to the CD8+ T-cell response at the population level creates challenges for vaccine design.
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Linfocitos T CD8-positivos/inmunología , Evolución Molecular , Hepacivirus/genética , Hepatitis C/inmunología , Mutación , Proteínas no Estructurales Virales/genética , Linfocitos T CD8-positivos/virología , Proteínas Portadoras/genética , Proteínas Portadoras/inmunología , Análisis Mutacional de ADN , Contaminación de Medicamentos , Epítopos , Femenino , Genotipo , Alemania Oriental , Antígenos HLA-B/inmunología , Hepacivirus/inmunología , Hepatitis C/virología , Humanos , Inmunoglobulinas/efectos adversos , Péptidos y Proteínas de Señalización Intracelular , Modelos Genéticos , Modelos Estadísticos , Datos de Secuencia Molecular , Fenotipo , Filogenia , Proteínas no Estructurales Virales/inmunologíaRESUMEN
BACKGROUND & AIMS: The CCR5Δ32 mutation has been suspected to adversely affect outcomes of HCV infection, although reports have remained controversial. Here, we investigated the relative genetic contributions of the CCR5Δ32 deletion and the IL28B rs12979860 polymorphisms to spontaneous clearance of hepatitis C in a single-source outbreak. METHODS: We retrieved 396 Caucasian women (119 women with spontaneous HCV clearance) who had been infected with HCV genotype 1-contaminated anti-D immunoglobulin in 1978, and determined their IL28B and CCR5 alleles. RESULTS: IL28B CC, CT, and TT genotypes were found in 35.4%, 50%, and 14.6% of patients and corresponded to spontaneous clearance rates of 50%, 21.2%, and 12.1% (Chi(2)=38.7, p=5.0×10(-10)), respectively. CCR5 WT/WT, WT/Δ32, and Δ32/Δ32 genotypes were observed in 76%, 22.7%, and 1.3% of patients and corresponded to clearance rates of 33.2%, 21.2%, and 0% (Chi(2)=6.9, p=0.009), respectively. In a stepwise forward-conditional multivariate regression model both CCR5 (OR 2.1, p=0.01 for WT/WT) and IL28B genetic variants (OR 4.3, p=4.6×10(-10) for the C/C genotype) were identified as independent predictors of spontaneous HCV clearance. Importantly, favorable response rates were associated with the IL28B CC genotype only in CCR5 wild-type homozygous women, while HCV clearance in CCR5Δ32 carriers remained poor even in patients with the rs12979860 CC genotype. CONCLUSIONS: Both IL28B rs1297860 and CCR5Δ32 allelic variants are independent genetic determinants of spontaneous HCV clearance. The variable relative distribution between IL28B rs1297860 and CCR5Δ32 allelic variants in different populations may have masked the role of the CCR5Δ32 mutation in some studies.
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Hepatitis C/genética , Interleucinas/genética , Receptores CCR5/genética , Alelos , Estudios de Casos y Controles , Estudios de Cohortes , Brotes de Enfermedades , Contaminación de Medicamentos , Femenino , Frecuencia de los Genes , Genotipo , Alemania/epidemiología , Hepatitis C/epidemiología , Hepatitis C/inmunología , Hepatitis C/transmisión , Hepatitis C/virología , Humanos , Interferones , Polimorfismo de Nucleótido Simple , Eliminación de SecuenciaRESUMEN
BACKGROUND & AIMS: A single nucleotide polymorphism (SNP) upstream of the IL28B gene has been associated with response of patients with chronic hepatitis C to therapy with pegylated interferon and ribavirin and also with spontaneous clearance of acute hepatitis C in a heterogeneous population. We analyzed the association between IL28B and the clinical presentation of acute hepatitis C virus (HCV) infection in a homogeneous population. METHODS: We analyzed the SNP rs12979860 in 190 women from the German anti-D cohort (infected with HCV genotype 1b via contaminated rhesus prophylaxis) and its association with spontaneous clearance. Clinical data were available in 136 women with acute infection who were also evaluated for IL28B genotype. Based on results of a TaqMan polymerase chain reaction assay, the rs12979860 SNP genotypes studied were C/C, C/T, or T/T. RESULTS: Spontaneous clearance was more common in patients with the C/C genotype (43/67; 64%) compared with C/T (22/90; 24%) or T/T (2/33; 6%) (P < .001). Jaundice during acute infection was more common among patients with C/C genotype (32.7%) than non-C/C patients (with C/T or T/T) (16.1%; P = .032). In C/C patients, jaundice during acute infection was not associated with an increased chance of spontaneous clearance (56.3%) compared with those without jaundice (60.6%). In contrast, in non-C/C patients, jaundice was associated with a higher likelihood of spontaneous clearance (42.9%) compared with those without jaundice (13.7%). CONCLUSIONS: The SNP rs12979860 upstream of IL28B is associated with spontaneous clearance of HCV. Women with the C/T or T/T genotype who did not develop jaundice had a lower chance of spontaneous clearance of HCV infection.
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ADN/genética , Hepatitis C/genética , Interleucinas/genética , Ictericia/genética , Polimorfismo Genético , Enfermedad Aguda , Adulto , Femenino , Estudios de Seguimiento , Genotipo , Hepatitis C/complicaciones , Hepatitis C/metabolismo , Humanos , Interferones , Interleucinas/metabolismo , Ictericia/etiología , Ictericia/metabolismo , Reacción en Cadena de la Polimerasa , Pronóstico , Estudios Retrospectivos , Factores de Tiempo , Adulto JovenRESUMEN
The inherent sequence diversity of the hepatitis C virus (HCV) represents a major hurdle for the adaptive immune system to control viral replication. Mutational escape within targeted CD8 epitopes during acute HCV infection has been well documented and is one possible mechanism for T-cell failure. HLA-B*08 was recently identified as one HLA class I allele associated with spontaneous clearance of HCV replication. Selection of escape mutations in the immunodominant HLA-B*08-restricted epitope HSKKKCDEL(1395-1403) was observed during acute infection. However, little is known about the impact of escape mutations in this epitope on viral replication capacity. Their previously reported reversion back toward the consensus residue in patients who do not possess the B*08 allele suggests that the consensus sequence in this epitope is advantageous for viral replication in the absence of immune pressure. The aim of this study was to determine the impact of mutational escape from this immunodominant epitope on viral replication. We analyzed it with a patient cohort with chronic HCV genotype 1b infection and in a single-source outbreak (genotype 1b). Sequence changes in this highly conserved region are rare and selected almost exclusively in the presence of the HLA-B*08 allele. When tested in the subgenomic replicon (Con1), the observed mutations reduce viral replication compared with the prototype sequence. The results provide direct evidence that escape mutations in this epitope are associated with fitness costs and that the antiviral effect of HLA-B*08-restricted T cells is sufficiently strong to force the virus to adopt a relatively unfavorable sequence.
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Linfocitos T CD8-positivos/inmunología , Antígenos HLA-B/fisiología , Hepacivirus/inmunología , Proteínas no Estructurales Virales/inmunología , Alelos , Epítopos de Linfocito T/química , Genotipo , Antígenos HLA-B/genética , Hepacivirus/genética , Hepacivirus/fisiología , Humanos , Epítopos Inmunodominantes , Mutación , Replicación ViralRESUMEN
For many aspects of HCV research it would be very useful to have a set of replicons in which different genome regions are swapped by corresponding fragments from isolates of the same viral strain that might demonstrate different biological characteristics or bear evolving antigenic determinants. The isolates of the same HCV strain that are necessary for generation of such hybrid replicons might be obtained from a single-source outbreak of HCV infection. One such outbreak caused by the HCV AD78 strain, occurred in Germany due to infection of women by contaminated anti-D globulin. Using a sequential substitution of different segments of the Con1 replicon with the corresponding fragments from the AD78 strain of HCV, a set of chimeric Con1/AD78 subgenomic and full-length, AD78-based genomic replicons were generated. These replicons might be used as a new experimental tool for different aspects of HCV research, including studies of the nature of isolate-specific differences in interactions of the replicon with the host cell and analysis of the mechanisms of HCV resistance to antivirals. The newly generated full-length replicon can also be used for preparation of AD78-specific target cell lines, which may be invaluable for the analysis of the evolution of HCV cellular immune responses in the cohort of patients infected with the HCV AD78 strain.
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Brotes de Enfermedades , Hepacivirus/genética , Hepatitis C/epidemiología , Replicón , Replicación Viral , Línea Celular , Variación Genética , Hepacivirus/fisiología , Hepatitis C/virología , Humanos , Plásmidos/genéticaRESUMEN
The high incidence of hepatitis C virus (HCV) persistence raises the question of how HCV interferes with host immune responses. Studying a single-source HCV outbreak, we identified an HCV mutation that impaired correct carboxyterminal cleavage of an immunodominant HLA-A2-restricted CD8 cell epitope that is frequently recognized by recovered patients. The mutation, a conservative HCV nonstructural protein 3 (NS3) tyrosine to phenylalanine substitution, was absent in 54 clones of the infectious source, but present in 15/21 (71%) HLA-A2-positive and in 11/24 (46%) HLA-A2-negative patients with chronic hepatitis C. In order to analyze whether the mutation affected the processing of the HLA-A2-restricted CD8 cell epitope, mutant and wild-type NS3 polypeptides were digested in vitro with 20S constitutive proteasomes and with immunoproteasomes. The presence of the mutation resulted in impaired carboxyterminal cleavage of the epitope. In order to analyze whether impaired epitope processing affected T cell priming in vivo, HLA-A2-transgenic mice were infected with vaccinia viruses encoding either wild-type or mutant HCV NS3. The mutant induced fewer epitope-specific, IFN-gamma;-producing and fewer tetramer(+) cells than the wild type. These data demonstrate how a conservative mutation in the flanking region of an HCV epitope impairs the induction of epitope-specific CD8(+) T cells and reveal a mechanism that may contribute to viral sequence evolution in infected patients.
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Cisteína Endopeptidasas/metabolismo , Epítopos , Hepacivirus/genética , Hepacivirus/inmunología , Complejos Multienzimáticos/metabolismo , Mutación , Secuencia de Aminoácidos , Animales , Linfocitos T CD8-positivos/inmunología , Antígeno HLA-A2/genética , Antígeno HLA-A2/inmunología , Hepacivirus/metabolismo , Hepatitis C/metabolismo , Humanos , Ratones , Ratones Transgénicos , Datos de Secuencia Molecular , Complejo de la Endopetidasa Proteasomal , Alineación de Secuencia , Virus Vaccinia/genética , Virus Vaccinia/metabolismo , Proteínas no Estructurales Virales/genética , Proteínas no Estructurales Virales/metabolismoRESUMEN
To model HCV resistance to a treatment with interferon-alpha (IFN-alpha) and ribavirin, Huh7 cells, bearing HCV subgenomic replicons, were treated with these compounds for several weeks. Analysis of the cell clones, which were able to support replication of HCV RNA in the presence of high concentrations of these antivirals, demonstrated that the observed resistance was due to changes in the host cell phenotype but not to the emergence of resistant variants of the replicon. No changes in the type I IFN receptor mRNA levels or sequences were found in IFN-treated cells suggesting that the observed resistance of replicon-containing cells to IFN-alpha was caused by modifications of some other cellular factors. The resistance of cells to high concentrations of ribavirin was due to a single point mutation in the NS5A gene of the HCV replicon, and was not associated with a defect in a ribavirin uptake. This mutation, however, did not change the sensitivity of the replicon itself to this antiviral.
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Farmacorresistencia Viral , Hepacivirus/efectos de los fármacos , Interferón-alfa/farmacología , Replicón/efectos de los fármacos , Ribavirina/farmacología , Línea Celular , Genoma Viral , Hepacivirus/genética , Hepacivirus/fisiología , Pruebas de Sensibilidad Microbiana , Transfección , Replicación Viral/efectos de los fármacosRESUMEN
AIM: Previous studies suggest that loss of bone mineral density (BMD) frequently occurs in patients with chronic viral liver disease, presenting with histologically proven liver cirrhosis. However, little is known about the occurrence of bone disease in non-cirrhotic patients with chronic hepatitis B or C. Therefore, it was the aim of this study to evaluate this particular population for BMD and bone turnover markers. METHODS: Biochemical markers of bone turnover and BMD were measured in 43 consecutive patients with HCV (n = 30) or HBV (n = 13) infection without histological evidence for liver cirrhosis. Mean age was 49 years (range 26-77 years). BMD was measured by dual X-ray absorptiometry in the femoral neck (FN) and the lumbar spine (LS) region. In addition, bone metabolism markers were measured. RESULTS: BMD was lowered in 25 (58%) of the patients with chronic hepatitis B or C (FN: 0.76 (0.53-0.99); LS: 0.96 (0.62-1.23) g/cm(2)). Eight (32%) osteopenic patients were diagnosed with osteoporosis. Bone-specific alkaline phosphatase (P = 0.005) and intact parathyroid hormone (iPTH) (P = 0.001) were significantly elevated in the more advanced stages of fibrosis. Mean T-score value was lower in patients with chronic hepatitis C as compared to patients suffering from chronic hepatitis B; however, the difference was not statistically significant (P = 0.09). CONCLUSION: There was a significantly reduced BMD in non-cirrhotic patients with chronic hepatitis B or C infection. Alterations of bone metabolism already occurred in advanced liver fibrosis without cirrhosis. According to our results, these secondary effects of chronic viral hepatitis should be further investigated.
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Densidad Ósea , Huesos/metabolismo , Hepatitis B Crónica/metabolismo , Hepatitis C Crónica/metabolismo , Osteoporosis/metabolismo , Adulto , Anciano , Biomarcadores , Femenino , Hepatitis B Crónica/complicaciones , Hepatitis C Crónica/complicaciones , Humanos , Cirrosis Hepática , Masculino , Persona de Mediana Edad , Osteoporosis/complicaciones , Osteoporosis/patologíaRESUMEN
INTRODUCTION: Non-invasive assessment of steatosis and fibrosis is of growing relevance in non-alcoholic fatty liver disease (NAFLD). 1H-Magnetic resonance spectroscopy (1H-MRS) and the ultrasound-based controlled attenuation parameter (CAP) correlate with biopsy proven steatosis, but have not been correlated with each other so far. We therefore performed a head-to-head comparison between both methods. METHODS: Fifty patients with biopsy-proven NAFLD and 15 healthy volunteers were evaluated with 1H-MRS and transient elastography (TE) including CAP. Steatosis was defined according to the percentage of affected hepatocytes: S1 5-33%, S2 34-66%, S3 ≥67%. RESULTS: Steatosis grade in patients with NAFLD was S1 36%, S2 40% and S3 24%. CAP and 1H-MRS significantly correlated with histopathology and showed comparable accuracy for the detection of hepatic steatosis: areas under the receiver-operating characteristics curves were 0.93 vs. 0.88 for steatosis ≥S1 and 0.94 vs. 0.88 for ≥S2, respectively. Boot-strapping analysis revealed a CAP cut-off of 300 dB/m for detection of S2-3 steatosis, while retaining the lower cut-off of 215 dB/m for the definition of healthy individuals. Direct comparison between CAP and 1H-MRS revealed only modest correlation (total cohort: râ=â0.63 [0.44, 0.76]; NAFLD cases: râ=â0.56 [0.32, 0.74]). For detection of F2-4 fibrosis TE had sensitivity and specificity of 100% and 98.1% at a cut-off value of 8.85 kPa. CONCLUSION: Our data suggest a comparable diagnostic value of CAP and 1H-MRS for hepatic steatosis quantification. Combined with the simultaneous TE fibrosis assessment, CAP represents an efficient method for non-invasive characterization of NAFLD. Limited correlation between CAP and 1H-MRS may be explained by different technical aspects, anthropometry, and presence of advanced liver fibrosis.
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Diagnóstico por Imagen de Elasticidad , Espectroscopía de Resonancia Magnética/métodos , Enfermedad del Hígado Graso no Alcohólico/diagnóstico , Adulto , Anciano , Biopsia , Estudios de Casos y Controles , Comorbilidad , Femenino , Humanos , Hígado/metabolismo , Hígado/patología , Cirrosis Hepática/patología , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Low-density lipoprotein receptor (LDLR) is involved in the entry of hepatitis C virus (HCV) in host cells. We investigated whether three single-nucleotide alterations within LDLR might be associated with the course of hepatitis C infection and response to antiviral therapy. We enrolled 651 individuals with chronic HCV infection who had received interferon-based combination therapy, 174 individuals with self-limited HCV infection, and 516 healthy controls. LDLR c.1171G>A, c.1413G>A, and c.*52G>A genotyping was performed by real-time PCR-based assays. HCV genotype 1-infected individuals who were homozygous for 3'UTR c.*52G were at increased risk for virologic non-response to antiviral therapy compared to virologic responders (66.3% vs. 51.0%, p=0.001). Furthermore, compared to healthy controls, self-limited HCV genotype 1 infection was significantly associated with c.1171A (15.1% vs. 6.6%, p=0.006) and negatively associated with c.1413G>A heterozygosity (33.0% vs. 46.1%, p=0.023). The data indicate that LDLR alterations are correlated with response to interferon-based combination therapy and with self-limitation of HCV 1 infection.
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Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/genética , Receptores de LDL/genética , Regiones no Traducidas 3' , Adulto , Anciano , Antivirales/uso terapéutico , Estudios de Casos y Controles , Estudios Transversales , Exones , Femenino , Genotipo , Humanos , Interferones/uso terapéutico , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Polimorfismo de Nucleótido Simple , Inducción de Remisión , Remisión Espontánea , Adulto JovenRESUMEN
The hepatitis C virus (HCV) subgenomic replicon system was used to study a possible involvement of nonstructural protein 5A (NS5A) in the mechanisms of HCV resistance to interferon alpha (IFN-alpha). A series of chimeric HCV replicons was constructed. In these replicons, the NS5A gene in the backbone of the Con1 replicon was swapped by corresponding fragments obtained from four IFN-alpha responder and four IFN-alpha nonresponder patients that had been infected with the same HCV AD78 strain. Experiments with transfected Huh7 cells did not reveal significant differences in sensitivity of HCV RNA replication to IFN-alpha in cell clones, bearing chimeric Con1/AD78 replicons with NS5A sequences from IFN responders and nonresponders. Thus, these data provide no evidence that the NS5A protein contributes to the resistance of HCV replication to IFN-alpha.
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Antivirales/farmacología , Hepacivirus/efectos de los fármacos , Interferón Tipo I/farmacología , Proteínas no Estructurales Virales/fisiología , Replicación Viral/efectos de los fármacos , Secuencia de Aminoácidos , Antivirales/uso terapéutico , Línea Celular Tumoral , Farmacorresistencia Viral , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/virología , Humanos , Interferón Tipo I/uso terapéutico , Datos de Secuencia Molecular , Proteínas Recombinantes , Recombinación Genética , Replicón/genética , Alineación de Secuencia , Proteínas no Estructurales Virales/genéticaRESUMEN
BACKGROUND/AIMS: The natural course of the hepatitis C virus genotype 1b (HCV-1b) infection is still unclear but important for therapeutic decisions. There are few unbiased long-term follow-up studies with known dates of infection. METHODS: Between August 1978 and March 1979, 14 HCV-1b contaminated batches of anti-D immunoglobulin had been administered to 2867 women for prophylaxis of rhesus isoimmunization throughout East Germany. We reexamined 1980 women, representing 70% of the total cohort of 15 centers. RESULTS: After application of the contaminated anti-D, 93% of the recipients developed an acute hepatitis C. After 25 years, 86% of the 1833 affected women still tested positive for hepatitis C virus antibodies and 46% for HCV RNA. Only nine (0.5%) had overt liver cirrhosis, 30 women (1.5%) developed pre-cirrhotic stages and one HCC was diagnosed. Ten (0.5%) died of HCV related complications, half of these related to additional comorbidity. In the last 5 years, a continuous, but low increase of fibrotic scores was observed. CONCLUSIONS: Young women without comorbidity may clear HCV (1b) infection in more than half of the cases, or develop mild chronic hepatitis C. We confirmed the low risk of progression to cirrhosis in this cohort within 25 years.