Respiratory syncytial virus vs. Influenza virus infection: mortality and morbidity comparison over 7 epidemic seasons in an elderly population.

BACKGROUND: Respiratory syncytial virus (RSV) infection is gaining interest due to the recent development of vaccines, but it is still misdiagnosed in the elderly. The primary objective was to compare all-cause mortality at day 30. Secondary objectives were to compare clinical presentation, and rates of consolidative pneumonia, hospitalization, and intensive care unit (ICU) admission. METHODS: Single-centre retrospective study conducted in a French university hospital during 7 epidemic seasons. All patients aged ≥75 years were included. RESULTS: 558 patients were included: 125 with RSV and 433 with Influenza. Median age was 84.8 years. RSV patients had more respiratory symptoms (wheezing, dyspnea), whereas Influenza patients had more general symptoms (fever, asthenia, myalgia). Consolidative pneumonia (28.8% vs. 17.2%; p = 0.004), hospitalization rates (83.2% vs. 70%; p = 0.003), ICU admissions (7.2% vs. 3.0%; p = 0.034) and length of stay (9 days [2-16] vs. 5 days [0-12]; p = 0.002), were higher in the RSV group. Mortality rates at day 30 were comparable (RSV 9.6%, Influenza 9.7%; p = 0.973). CONCLUSIONS: This study included the largest cohort of RSV-infected patients aged over 75, documented in-depth thus far. RSV shares a comparable mortality rate with Influenza but is associated with higher rates of consolidative pneumonia, hospitalization, ICU admissions, and extended hospital stays.

Clinical description of the broad range of neurological presentations of COVID-19: A retrospective case series.

BACKGROUND: Neurological disorders associated with SARS-CoV-2 infection represent a clinical challenge because they encompass a broad neurological spectrum and may occur before the diagnosis of COVID-19. METHODS: In this monocentric retrospective case series, medical records from patients with acute neurological disorders associated with SARS-CoV-2 infection from medicine departments of an academic center in Paris area were collected between March 15th and May 15th 2020. Diagnosis of SARS-CoV-2 was ascertained through specific RT-PCR in nasopharyngeal swabs or based on circulating serum IgG antibodies. RESULTS: Twenty-six patients diagnosed with SARS-CoV-2 infection presented with neurological disorders: encephalitis (N=8), encephalopathy (N=6), cerebrovascular events (ischemic strokes N=4 and vein thromboses N=2), other central nervous system (CNS) disorders (N=4), and Guillain-Barré syndrome (N=2). The diagnosis of SARS-CoV-2 was delayed on average 1.6 days after the onset of neurological disorder, especially in case of encephalitis 3.9 days, encephalopathy 1.0 day, and cerebrovascular event 2.7 days. CONCLUSIONS: Our study confirms that COVID-19 can yield a broad spectrum of neurological disorders. Because neurological presentations of COVID-19 often occur a few days before the diagnosis of SARS-COV-2 infection, clinicians should take preventive measures such as patient isolation and masks for any new admission to avoid nosocomial infections. Anti-SARS-CoV2 antibody detection in RT-PCR SARS CoV-2 negative suspected cases is useful to confirm a posteriori the diagnosis of atypical COVID-19 presentations.

Pathogen identification by shotgun metagenomics of patients with necrotizing soft-tissue infections.

BACKGROUND: Necrotizing soft-tissue infections (NSTIs) are life threatening, requiring broad-spectrum antibiotics. Their aetiological diagnosis can be limited by poor performance of cultures and administration of antibiotics before surgery. OBJECTIVES: We aimed (i) to compare 16S-targeted metagenomics (TM) and unbiased semiquantitative panmicroorganism DNA- and RNA-based shotgun metagenomics (SM) with cultures, (ii) to identify patients who would best benefit from metagenomics approaches and (iii) to detect the microbial pathogens in surrounding non-necrotic 'healthy' tissues by SM-based methods. METHODS: A prospective observational study was performed to assess the analytical performance of standard cultures, TM and SM on tissues from 34 patients with NSTIs. Pathogen identification obtained with these three methods was compared. RESULTS: Thirty-four necrotic and 10 healthy tissues were collected from 34 patients. The performance of TM was inferior to that of the other methods (P < 0·05), whereas SM performed better than standard culture, although the result was not statistically significant (P = 0·08). SM was significantly more sensitive than TM for the detection of all bacteria (P = 0·02) and more sensitive than standard culture for the detection of anaerobic bacteria (P < 0·01). There was a strong correlation (r = 0·71, Spearman correlation coefficient) between the semiquantitative abundance of bacteria in the culture and the bacteria-to-human sequence ratio in SM. Low amounts of bacterial DNA were found in healthy tissues, suggesting a bacterial continuum between macroscopically 'healthy' and necrotic tissue. CONCLUSIONS: SM showed a significantly better ability to detect a broader range of pathogens than TM and identify strict anaerobes than standard culture. Patients with diabetes with NSTIs appeared to benefit most from SM. Finally, our results suggest a bacterial continuum between macroscopically 'healthy' non-necrotic areas and necrotic tissues. What's already known about this topic? Necrotizing soft-tissue infections (NSTIs) are characterized by rapidly progressive necrosis of subcutaneous tissues and high mortality, despite surgical debridement combined with broad-spectrum antibiotics. The spectrum of potentially involved pathogens is very large, and identification is often limited by the poor performance of standard cultures, which may be impaired by previous antibiotic intake. Metagenomics-based approaches show promise for better identification of the pathogens that cause these infections, but they have not been evaluated in this medical context. What does this study add? Shotgun metagenomics (SM) showed higher sensitivity than 16S rRNA gene sequencing and a better ability than culture to detect anaerobic bacteria. As a result, a significant proportion of infections with bacteria, such as Pasteurella multocida or Clostridium perfringens, were detected only by SM. SM bacterial quantification enabled better detection of low amounts of bacterial DNA from macroscopically 'healthy' tissue, suggesting a subclinical infectious extension. What is the translational message? The high analytical performance of SM shown in this study should allow its future implementation for the diagnosis of necrotizing fasciitis, complementing or replacing routine methods. The large amount of data, including additional information on antimicrobial resistance, virulence profiles and metabolic adaptation of the pathogens, will improve microbiological documentation. Our results will improve our understanding of infectious pathophysiology in the future, leading to potentially better medical care.

Multicenter Evaluation of the Cepheid Xpert Hepatitis C Virus Viral Load Assay.

Viral load monitoring for hepatitis C virus (HCV) is necessary to diagnose infection and monitor response to therapy, but the tests involved are currently confined to specialist institutions. There is a need for a fast, accurate assay with limited operator input to enhance the access to viral load monitoring. We evaluated the quantification of HCV RNA in serum and plasma by the Cepheid Xpert HCV Viral Load assay in comparison to the Abbott RealTime HCV assay. Serum and plasma samples were gathered from HCV-infected individuals at four international sites. These were tested with the Xpert HCV Viral Load assay, and results were compared to quantification by the Abbott RealTime HCV assay. An external quality assessment panel of eight samples was also tested. In total, 614 samples were analyzed in the study, and the qualitative results agreed on the two platforms for 588 (95.8%) samples. Further analysis of 396 samples quantified by both tests showed strong correlation (correlation coefficient r = 0.99) across the quantifiable range, with Bland-Altman plot data showing a mean difference (±1.96 standard deviation) of 0.03 ± 0.44 log10 IU/ml. In the external quality assessment panel, the Xpert HCV Viral Load assay results (quantified in log10 IU per milliliter) were within 1 standard deviation of the target value for all but one sample, which was also similarly misquantified by the Abbott RealTime HCV assay. The Xpert HCV Viral Load assay performs well compared to a market-leading HCV viral load test and should be considered for instances where rapid near-to-patient testing is required.

Performance of rapid diagnostic tests for the detection of antibodies to hepatitis C virus in whole blood collected on dried blood spots.

Rapid diagnostic tests (RDTs) represent an attractive alternative to enzyme immunoassays. A total of 207 individuals, including 68 HCV-seronegative subjects, 10 patients with resolved infection and 129 patients with chronic HCV infection, were studied. The specificity of RDT detection of anti-HCV antibodies in whole blood was 100% with the four RDTs tested: OraQuick(®) HCV Rapid Antibody Test, First Response HCV Card Test, ASSURE HCV Rapid Test and MultiSure HCV Antibody Assay. Their diagnostic sensitivity varied between 98.6% and 100%. RDT detection of anti-HCV antibody in whole blood collected on dried blood spots appears to be a promising new tool for broadscale screening of HCV infection in high- to medium-risk populations.

Association between IL28B polymorphism, TNFα and biomarkers of insulin resistance in chronic hepatitis C-related insulin resistance.

TNFα has been shown to play a role in hepatitis C virus (HCV)-induced insulin resistance (IR). Polymorphism of the IL28B gene that encodes IFN-lambda 3 may be associated with IR through modulation of TNFα. The aim of this study was to investigate the relationship between IL28B rs12979860 genotype, the level of TNFα activation and the degree of IR in patients with chronic hepatitis C. One hundred and thirty-three nondiabetic genotype 1 HCV-infected patients with biopsy proven noncirrhotic hepatitis C were investigated for IR (using HOMA index), IL28B rs12979860 genotype and fasting circulating levels of soluble receptor 1 of TNFα (sTNFR1) and adipokines: leptin, adiponectin and IL-6. The HOMA-IR was positively correlated with serum levels of leptin (r = 0.35, P < 0.0001) and sTNFR1 (r = 0.35, P < 0.0001) but not with IL-6 or adiponectin. IL28B rs12979860 CC genotype was observed in 35% patients. Genotype CC and nongenotype CC patients were similar in terms of HOMA-IR (means 1.6 ± 0.9 vs 1.7 ± 1.4) and had similar circulating levels of sTNFR1 and adipokines. Independent factors associated with IR were ferritin (OR = 1.002, P = 0.02), leptin (OR = 1.06, P = 0.02) and sTNFR1 (OR = 7.9, P = 0.04). This study suggests that in nondiabetic, noncirrhotic, HCV genotype 1-infected patients, there is no relationship between IL28B rs12979860 genotype and HOMA-IR or sTNFR1 level. HCV-related IR may be mediated through TNFα independent of IL28B genotype.

A practical guide for the use of boceprevir and telaprevir for the treatment of hepatitis C.

The aim of this study is to review clinical trial data on the newly approved protease inhibitors boceprevir and telaprevir to develop consensus recommendations on the optimal use of these agents for the treatment of patients with chronic hepatitis C virus (HCV) infection. An expert panel of seven leading authorities in viral hepatitis was convened to establish and disseminate a practical guide on best practices for incorporating boceprevir and telaprevir into therapy for HCV infection in both treatment-naive and treatment-experienced patients. The topics covered include selecting candidates for boceprevir- or telaprevir-based treatments, predictors of response and early viral kinetics, response-guided therapy approaches, on-treatment management strategies to optimize the likelihood of response and minimize the risk of drug resistance, management of adverse effects during therapy and key considerations for special populations. The expert panel incorporated the best available clinical evidence into recommendations on how boceprevir and telaprevir should be used in the clinical setting. They indicated how treatment regimens may differ according to the baseline factors, such as presence of cirrhosis and when therapy may need to be modified or stopped altogether because of adverse events or poor virologic response. This practical guide will serve as a valuable resource for clinicians embarking on the new treatment paradigm of boceprevir or telaprevir in combination with peginterferon/ribavirin for chronic genotype 1 HCV infection.

IL28B polymorphisms predict reduction of HCV RNA from the first day of therapy in chronic hepatitis C.

BACKGROUND & AIMS: Single nucleotide polymorphisms (SNPs) associated with IL28B influence the outcome of peginterferon-α/ribavirin therapy of chronic hepatitis C virus (HCV) infection. We analyzed the kinetics of HCV RNA during therapy as a function of IL28B SNPs. METHODS: IL28B SNPs rs8099917, rs12979860, and rs12980275 were genotyped in 242 HCV treatment-naïve Caucasian patients (67% genotype 1, 28% genotype 2 or 3) receiving peginterferon-α2a (180 µg weekly) and ribavirin (1000-1200 mg daily) with serial HCV-RNA quantifications. Associations between IL28B polymorphisms and early viral kinetics were assessed, accounting for relevant covariates. RESULTS: In the multivariate analyses for genotype 1 patients, the T allele of rs12979860 (T(rs12979860)) was an independent risk factor for a less pronounced first phase HCV RNA decline (log(10) 0.89IU/ml among T carriers vs. 2.06 among others, adjusted p < 0.001) and lower rapid (15% vs. 38%, adjusted p = 0.007) and sustained viral response rates (48% vs. 66%, adjusted p < 0.001). In univariate analyses, T(rs12979860) was also associated with a reduced second phase decline (p = 0.002), but this association was no longer significant after adjustment for the first phase decline (adjusted p = 0.8). In genotype 2/3 patients, T(rs12979860) was associated with a reduced first phase decline (adjusted p = 0.04), but not with a second phase decline. CONCLUSIONS: Polymorphisms in IL28B are strongly associated with the first phase viral decline during peginterferon-α/ribavirin therapy of chronic HCV infection, irrespective of HCV genotype.

Microdiversity of Enterococcus faecalis isolates in cases of infective endocarditis: selection of non-synonymous mutations and large deletions is associated with phenotypic modifications.

Context: Today, infective endocarditis (IE) caused by Enterococcus faecalis represents 10% of all IE and is marked by its difficult management and the frequency of relapses. Although the precise reasons for that remain to be elucidated, the evolution of the culprit strain under selective pressure through microdiversification could be, at least in part, involved. Material and methods: To further study the in situ genetic microdiversity and its possible phenotypic manifestations in E. faecalis IE, we sequenced and compared multiple isolates from the valves, blood culture and joint fluid of five patients who underwent valvular surgery. Growth rate and early biofilm production of selected isolates were also compared. Results: By sequencing a total of 58 E. faecalis genomes, we detected a considerable genomic microdiversity, not only among strains from different anatomical origins, but also between isolates from the same studied cardiac valves. Interestingly, deletions of thousands of bases including the well-known virulence factors ebpA/B/C, and srtC, as well as other large prophage sequences containing genes coding for proteins implicated in platelet binding (PlbA and PlbB) were evidenced. The study of mutations helped unveil common patterns in genes related to the cell cycle as well as central metabolism, suggesting an evolutionary convergence in these isolates. As expected, such modifications were associated with a significant impact on the in-vitro phenotypic heterogeneity, growth, and early biofilm production. Conclusion: Genome modifications associated with phenotypic variations may allow bacterial adaptation to both antibiotic and immune selective pressures, and thus promote relapses.

Prediction of nonSVR to therapy with pegylated interferon-alpha2a and ribavirin in chronic hepatitis C genotype 1 patients after 4, 8 and 12 weeks of treatment.

In patients with chronic hepatitis C genotype 1, the current algorithm for treatment discontinuation is based on no early virological response (<2 log decline in hepatitis C virus (HCV)-RNA) at 12 weeks. It is important to determine whether prediction of nonsustained virological response (NR) before 12 weeks can be robustly obtained by statistical methods. We used longitudinal discriminant analysis (LDA) to build and cross-validate models including baseline patient characteristics and measurements of serum HCV-RNA in the first 4, 8 or 12 weeks of treatment. The performance of each model was evaluated by the partial AUC (PA) index, exploring the accuracy of prediction in the range of high negative predictive values. Models were compared by computing 95% confidence intervals for the difference in PA indices. NR was best predicted before week 12 by a single HCV-RNA measurement at week 8 taken together with gender, BMI and age (W8 model, PA index = 0.857). This model was not inferior to models that included a measurement at week 12 (PA index = 0.831). The best model obtained with LDA within the first 4 weeks, which included measurements at days 4, 8 and at week 4, was found to be inferior to the week 8 model (PA index = 0.796). These results indicate that lack of sustained viral response is best predicted after 8 weeks of treatment and that waiting until 12 weeks does not improve the prediction.

[The liver and Europe]. / Le foie et l'Europe.

The past 30 years have been witnessing major progress in the knowledge and management of liver diseases. Approximately 29 million people in European Union suffer from chronic liver disease. However, liver diseases have been neglected by most European and national political and public health deciders. A number of measures should be implemented at the European and country levels: an efficient surveillance and data collection policy; broad information of the general population on the nature and importance of liver diseases and the means to diagnose and treat them; treatment and management policies; promotion of research on the causes, risk factors, prevention and management of liver diseases as well as on the most efficient interventions to reduce their incidence, prevalence, morbidity and mortality. The European Association for the Study of the Liver (EASL) has launched in 2006 an ambitious public policy and communication action in order to get recognition of liver diseases as a major cause of morbidity and mortality in Europe and push for appropriate measures. The future of hepatology as a specialty will depend on the success of this initiative.

Interferon and ribavirin therapy does not select for resistance mutations in hepatitis C virus polymerase.

Ribavirin has a minor and transient effect on hepatitis C virus (HCV) replication and has been suggested to select a novel mutation, F415Y, in the RNA-dependent RNA polymerase of subtype 1a viruses. Twenty-nine patients with chronic hepatitis C (subtyped by INNO LiPA as 1a, 17; 1b, 11; 1a/1b, 1) who were nonresponders to interferon-based therapies were identified retrospectively and screened at Baseline, week 24 of treatment, and 24 weeks post-treatment. Selection of resistance mutations, including at amino acid position 415 of the polymerase, was investigated. Using clonal sequencing and pyrosequencing of the NS5B gene, we screened for the F415Y resistance mutation among patients who received combination therapy with ribavirin and interferon α. Of the 15 subtype 1a patients treated with interferon plus ribavirin, only one had the F415Y change at week 24, and an F/Y mixture was still present 24 weeks after therapy. Four additional patients in this group had the F415Y change 24 weeks post-therapy. The NS5B genes were sequenced in order to identify amino acid changes associated with ribavirin therapy, but no evidence was found that ribavirin selects for particular amino acids in the RNA-dependent RNA polymerase. Ribavirin, a weak inhibitor of HCV replication, does not select for resistance mutations in the sequence of the HCV RNA polymerase.

[Virologic techniques for the diagnosis and monitoring of hepatitis B]. / Les techniques virologiques de diagnostic et de suivi de l'hépatite B.

Both serologic and molecular tools are useful for the diagnosis, monitoring and therapeutic management of viral hepatitis associated with hepatitis B virus (HBV). Compared with the standard tests to detect viral antigens and the antibodies directed against them, real-time PCR techniques today make it possible to quantify viral DNA more sensitively and more precisely. They thus replace the techniques previously used in most virology laboratories. New markers, such as the HBV genotype or the amino-acid substitution profile associated with HBV resistance to nucleoside and nucleotide analogs (NRTIs), can also be characterized by techniques based on sequencing or reverse hybridization. There is not currently any consensus about the first-line treatment for chronic HBV infection. Patients with a wild-type virus (HBe antigen-positive), a moderate viral load, and elevated serum alanine aminotransferase (from 2 to 5 times the upper limit of normal) are good candidates for treatment with pegylated interferon-alpha. Patients who are HBe antigen-positive and do not respond to this first-line treatment, as well as patients with chronic e-antigen-negative hepatitis B, are candidates for prolonged treatment, probably lifelong, by nucleoside or nucleotide analogs. Whatever the HBe serologic status and treatment, the efficacy of antiviral treatment is assessed by repeated measurements of viral load and serum alanine aminotransferase levels, in principle, every 12-24 months. In patients who are HBe antigen-positive, the efficacy of antiviral treatment is shown by the loss of HBe antigen, followed by the appearance of anti-HBe antibodies (HBe seroconversion), a reduction in viral load below 2x10(4)IU/mL and normalization of serum aminotransferase. In patients who are HBe antigen-negative or HBe antigen-positive but do not seroconvert after short-term treatment and who receive nucleoside or nucleotide analogs, the treatment objective is for HBV DNA to become undetectable by real-time PCR. Nonetheless, this objective is not always met, and it is recommended that viral replication be maintained at the lowest possible level for the longest possible time (ideally, lifelong). In all cases, when a virologic response to treatment is observed (significant reduction in viral load) and is followed by a relapse characterized by a viral load augmentation of at least 1 Log(10)IU/mL relative to the nadir, viral resistance to treatment must be suspected, after treatment adherence has been verified.

Viral kinetics analysis and virological characterization of treatment failures in patients with chronic hepatitis C treated with sofosbuvir and an NS5A inhibitor.

BACKGROUND: The combination of sofosbuvir (SOF) plus an NS5A inhibitor for 12 weeks is highly efficacious in patients with chronic hepatitis C. As the costs of generic production of sofosbuvir and NS5A inhibitor are rapidly decreasing, the combination of these DAAs will be the standard treatment in most low- to middle-income countries in the future. AIM: To identify key predictors of response that can be used to tailor treatment decisions. METHODS: A cohort of 216 consecutive patients infected with HCV genotype 1 (1a: n = 57; 1b: n = 77), 2 (n = 4), 3 (n = 33) or 4 (n = 44) were treated with sofosbuvir (SOF) + daclatasvir (n = 176) or SOF + ledipasvir (n = 40) for 12 weeks. The viral kinetics was analysed using the biphasic model and the cure boundary was used to predict time to clear HCV. RESULTS: The overall SVR rate was high (94.4%; n = 204), regardless of the time to viral suppression or low-level viraemia at the end of treatment. The model-based predicted HCV RNA levels at the end of treatment could not differentiate patients who did from those who did not achieve SVR. The presence of NS5A resistance-associated substitutions [position 28 (OR = 70.3, P<.001) and/or 31 (OR = 61.6, P = .002)] at baseline was predictive of virological failure in cirrhotic patients but was not associated with on-treatment viral kinetics. CONCLUSION: This real-world study confirms the excellent results of clinical trials with therapies based on a combination of SOF plus an NS5A inhibitor. It suggests that a personalized approach including baseline NS5A inhibitor resistance testing may inform treatment decisions in cirrhotic patients.

Hepatitis C virus population dynamics during infection.

Hepatitis C virus (HCV) behaves as an evolving viral quasispecies in its continuously changing environment. The study of HCV quasispecies population dynamics in experimental models and infected patients can provide useful information on factors involved in the HCV life cycle and pathogenicity. HCV quasispecies variability also has therapeutic implications, as the continuous generation and selection of fitter or truly resistant variants can allow the virus to escape control by antiviral drugs.

Prospective assessment of rapid diagnostic tests for the detection of antibodies to hepatitis C virus, a tool for improving access to care.

Large-scale hepatitis C screening is required to prevent further spread of the infection, improve access to care in the context of new hepatitis C virus (HCV) drug regimens without interferon-alpha and subsequently reduce the risk of long-term complications of chronic liver disease. Rapid diagnostic tests (RDTs) represent an attractive alternative to enzyme immunoassay using blood from venepuncture. The aim of the present study was to prospectively assess the clinical performance of CE-marked RDTs detecting anti-HCV antibodies in fingerstick capillary whole blood and/or oral fluid. A total of 513 individuals, including 318 patients with chronic HCV infection, 25 patients with resolved HCV infection and 170 HCV-seronegative individuals, were prospectively enrolled. The specificity of RDTs with fingerstick whole blood varied from 98.8% to 100%. The clinical sensitivity was high for the OraQuick(®) and Toyo(®) tests (99.4% and 95.8%, respectively), but low for the Labmen(®) test (63.1%). The specificity and clinical sensitivity in crevicular fluid were both satisfactory for the OraQuick(®) test (100% and 97.6%, respectively). HCV antibody RDTs were easy and rapid to perform in the context of patient care. They were highly specific. Both the OraQuick(®) and Toyo(®) tests reached the expected level of performance for wide-scale use, with a performance advantage for the OraQuick(®) HCV test. RDTs appear to be a promising new tool for wide-scale screening of HCV infection in high-risk to medium-risk populations. Hence, careful assessment of the performance of HCV RDTs must be recommended before they can be implemented in clinical practice.

Multicenter clinical evaluation of the new 3rd generation assay for detection of antibodies against hepatitis C virus on the VIDAS(®) system.

BACKGROUND: Detection of antibodies (anti-HCV) against hepatitis C virus (HCV) is indispensable for screening and diagnosis of viral hepatitis and for the viral safety of blood, tissue or organ donations. It gains additional importance by the new HCV drugs which improve the therapeutic possibilities dramatically. OBJECTIVE: To evaluate the performance of a newly developed immune assay for anti-HCV based on the well-established VIDAS platform. STUDY DESIGN: The assay was evaluated with samples from anti-HCV negative blood donors and from patients with or without HCV markers in six centres in France, Spain and Egypt. The status of the samples was determined by using CE-marked immune assays (Architect, AxSym, Prism, Vitros), two immunoblots (RIBA, Inno-Lia) and/or HCV RNA results. RESULTS: Specificity was 99.67% in 10,320 French blood donors without anti-HCV, 99.5% in 200 anti-HCV negative hospitalized European patients and 99.0% in 198 negative patients from Egypt. Sensitivity was 99.7% in 1054 patients pretested positive by other assays; 345 patients with known genotype had genotype 1-6; 61 patients were co-infected with HIV. VIDAS was reactive in 78% of 91 patients with uncertain or very weak anti-HCV. It became on average positive at day 37 with seroconversion panels. CONCLUSIONS: This multicentric, international study with >12,000 samples show that the new VIDAS anti-HCV assay is very suitable for screening and confirmation of HCV infection. Sensitivity, specificity and recognition of seroconversion compare favorably with well-established CE-marked tests and help to clarify discrepant results obtained with other assays.

Identification of a duplicated V3 domain in NS5A associated with cirrhosis and hepatocellular carcinoma in HCV-1b patients.

BACKGROUND: The NS5A protein of the hepatitis C virus has been shown to be involved in the development of hepatocellular carcinoma. OBJECTIVES: In a French multicenter study, we investigated the clinical and epidemiological features of a new HCV genotype 1b strain bearing a wide insertion into the V3 domain. STUDY DESIGN: We studied NS5A gene sequences in 821 French patients infected with genotype 1b HCV. RESULTS: We identified an uncharacterized V3 insertion without ORF disruption in 3.05% of the HCV sequences. The insertion comprised 31 amino-acids for the majority of patients; 3 patients had 27 amino-acids insertions and 1 had a 12 amino-acids insertion. Sequence identity between the 31 amino-acids insertions and the V3 domain ranged from 48 to 96% with E-values above 4e(-5), thus illustrating sequence homology and a partial gene duplication event that to our knowledge has never been reported in HCV. Moreover we showed the presence of the duplication at the time of infection and its persistence at least during 12 years in the entire quasispecies. No association was found with extrahepatic diseases. Conversely, patients with cirrhosis were two times more likely to have HCV with this genetic characteristic (p=0.04). Moreover, its prevalence increased with liver disease severity (from 3.0% in patients without cirrhosis to 9.4% in patients with both cirrhosis and HCC, p for trend=0.045). CONCLUSIONS: We identified a duplicated V3 domain in the HCV-1b NS5A protein for the first time. The duplication may be associated with unfavorable evolution of liver disease including a possible involvement in liver carcinogenesis.

Activity of the interferon-induced 2',5'-oligoadenylate synthetase in patients with chronic hepatitis C.

The interferon-induced 2',5'-oligoadenylate synthetase (2-5OAS) is responsible, at least in part, for the antiviral state established in cells in response to viral infections. The purpose of this work was to study the relationship between hepatitis C virus (HCV) infection and 2-5OAS in patients with chronic hepatitis C. Peripheral blood mononuclear cells (PBMC) of 27 patients with chronic hepatitis C were investigated, as well as PBMC of 10 control subjects. Then, the patients were treated with 3 mu interferon-alpha 2a three times per week. At month 3 of therapy, PBMC were sampled. Of the total PBMC samples obtained, half were used for determination of in vivo 2-5OAS activity. The remaining cells were cultured for 24 h in either the absence or presence of 500 U/ml of interferon-alpha 2a for the determination of in vitro 2-5OAS activity. The mean basal in vivo 2-5OAS activities were 3.6 +/- 2.8 nmol/10(6) cells in patients versus 1.6 +/- 1.1 nmol/10(6) cells in controls (p < 0.01). Basal in vivo 2-5OAS activity did not correlate with mean HCV viremia, quantified by a "branched DNA"-based assay. Before treatment, interferon-alpha was detected in the serum of 2 patients in 27. After a 24 h culture of PBMC in the presence of interferon, in vitro 2-5OAS activity was significantly induced in the PBMC of both the patients and the controls. However, in vitro induction of 2-5OAS activity was significantly lower in the PBMC of the patients than in the PBMC of the controls (p < 0.01). At month 3 therapy, in vivo 2-5OAS activity was significantly induced (20.5 +/- 17.9; p < 0.0001). In vitro IFN inductions of 2-5OAS activity in PBMC before treatment and at month 3 of therapy were not significantly different. In conclusion, in vivo 2-5OAS activity is significantly induced in patients with chronic hepatitis C, but endogenously produced interferon-alpha does not seem to be involved. Chronic induction of 2-5OAS activity results in a decreased sensitivity of PBMC to exogenous interferon induction. Whether this phenomenon plays a role in the resistance of chronic hepatitis C to interferon therapy remains uncertain.

Molecular tools for the treatment of hepatitis C.

The treatment of chronic hepatitis C is aimed at eliminating viral replication in order to prevent further evolution towards cirrhosis and hepatocellular carcinoma. Virological parameters include hepatitis C virus (HCV) genotype, qualitative viraemia, quantitative viral load and the characteristics of HCV quasi-species heterogeneity. These parameters can be used to predict and monitor the response to therapy, in order to help clinicians to tailor treatment of chronic hepatitis C and to better understand the molecular mechanisms underlying HCV resistance to antiviral drugs. Current knowledge on these various issues is reviewed in the present article.