Importance of primer selection for the detection of hepatitis C virus RNA with the polymerase chain reaction assay

Akt1 is involved in HCV release by promoting endoplasmic reticulum-to-endosome transition of infectious virions

AIMS

Hepatitis C virus (HCV) relies on the viral and host factors to complete its life cycle. It has evolved to profit from Akt activation at some stage in its life cycle through various mechanisms, notably by activating lipogenesis, which is crucial for infectious virions production.

MATERIALS AND METHODS

By employing an Akt-specific inhibitor, the impact of Akt on intracellular and extracellular infectivity was investigated. To ascertain the role of Akt in the HCV life cycle, the two-part cell culture-derived HCV infection protocol utilizing Akt1 small interfering RNAs (siRNAs) was implemented. The impact of Akt1 on intracellular HCV transition was determined using membrane flotation assay and proximity ligation assay coupled with Anti-Rab7 immunoprecipitation and immunofluorescence.

KEY FINDINGS

Akt1 silencing reduced infectious virions release to a degree comparable to that of ApoE, a host component involved in the HCV assembly and release, suggesting Akt1 was critical in the late stage of the HCV life cycle. Extracellular infectivity of HCV was inhibited by brefeldin A, and the inhibitory effect was augmented by Akt1 silencing and partially restored by ectopic Akt1 expression. Immunofluorescence revealed that Akt1 inhibition suppressed the interaction between HCV core protein and lipid droplet. Akt1 silencing impeded the transition of HCV from the endoplasmic reticulum to the endosome and hence inhibited the secretion of HCV infectious virions from the late endosome.

SIGNIFICANCE

Our study demonstrates that Akt1 has an impact on the lipogenesis pathway and plays a critical role in the assembly and secretion of infectious HCV.

A Novel Small Molecule Inhibits Hepatitis C Virus Propagation in Cell Culture

Hepatitis C virus (HCV) can cause acute and chronic infection that is associated with considerable liver-related morbidity and mortality. In recent years, there has been a shift in the treatment paradigm with the discovery and approval of agents that target specific proteins vital for viral replication. We employed a cell culture-adapted strain of HCV and human hepatoma-derived cells lines to test the effects of our novel small-molecule compound (AO13) on HCV. Virus inhibition was tested by analyzing RNA replication, protein expression, and virus production in virus-infected cells treated with AO13. Treatment with AO13 inhibited virus spread in cell culture and showed a 100-fold reduction in the levels of infectious virus production. AO13 significantly reduced the level of viral RNA contained within cell culture fluids and reduced the cellular levels of HCV core protein, suggesting that the compound might act on a late step in the viral life cycle. Finally, we observed that AO13 did not affect the release of infectious virus from infected cells. Docking studies and molecular dynamics analyses suggested that AO13 might target the NS5B RNA polymerase, however, real-time RT-PCR analyses of cellular levels of HCV RNA showed only an ∼2-fold reduction in viral RNA levels in the presence of AO13. Taken together, this study revealed that AO13 showed consistent, but low-level antiviral effect against HCV, although the mechanism of action remains unclear.

IMPORTANCE The discovery of curative antiviral drugs for a chronic disease such as HCV infection has encouraged drug discovery in the context of other viruses for which no curative drugs currently exist. Since we currently face a novel virus that has caused a pandemic, the need for new antiviral agents is more apparent than ever. We describe here a novel compound that shows a modest antiviral effect against HCV that could serve as a lead compound for future drug development against other important viruses such as SARS-CoV-2.

Massive Iatrogenic Outbreak of Human Immunodeficiency Virus Type 1 in Rural Cambodia, 2014-2015

Background

In 2014-2015, 242 individuals aged 2-89 years were newly diagnosed with human immunodeficiency virus type 1 (HIV-1) in Roka, a rural commune in Cambodia. A case-control study attributed the outbreak to unsafe injections. We aimed to reconstruct the likely transmission history of the outbreak.

Methods

We assessed in 209 (86.4%) HIV-infected cases the presence of hepatitis C virus (HCV) and hepatitis B virus (HBV). We identified recent infections using antibody (Ab) avidity testing for HIV and HCV. We performed amplification, sequencing, and evolutionary phylogenetic analyses of viral strains. Geographical coordinates and parenteral exposure through medical services provided by an unlicensed healthcare practitioner were obtained from 193 cases and 1499 controls during interviews.

Results

Cases were coinfected with HCV (78.5%) and HBV (12.9%). We identified 79 (37.8%) recent (<130 days) HIV infections. Phylogeny of 202 HIV env C2V3 sequences showed a 198-sample CRF01_AE strains cluster, with time to most recent common ancestor (tMRCA) in September 2013 (95% highest posterior density, August 2012-July 2014), and a peak of 15 infections/day in September 2014. Three geospatial HIV hotspots were discernible in Roka and correlated with high exposure to the practitioner (P = .04). Fifty-nine of 153 (38.6%) tested cases showed recent (<180 days) HCV infections. Ninety HCV NS5B sequences formed 3 main clades, 1 containing 34 subtypes 1b with tMRCA in 2012, and 2 with 51 subtypes 6e and tMRCAs in 2002-2003.

Conclusions

Unsafe injections in Cambodia most likely led to an explosive iatrogenic spreading of HIV, associated with a long-standing and more genetically diverse HCV propagation.

Distribution of HCV genotypes in Belgium from 2008 to 2015

Background

The knowledge of circulating HCV genotypes and subtypes in a country is crucial to guide antiviral therapy and to understand local epidemiology. Studies investigating circulating HCV genotypes and their trends have been conducted in Belgium. However they are outdated, lack nationwide representativeness or were not conducted in the general population.

Methods

In order to determine the distribution of different circulating HCV genotypes in Belgium, we conducted a multicentre study with all the 19 Belgian laboratories performing reimbursed HCV genotyping assays. Available genotype and subtype data were collected for the period from 2008 till 2015. Furthermore, a limited number of other variables were collected: some demographic characteristics from the patients and the laboratory technique used for the determination of the HCV genotype.

Results

For the study period, 11,033 unique records collected by the participating laboratories were used for further investigation.

HCV genotype 1 was the most prevalent (53.6%) genotype in Belgium, with G1a and G1b representing 19.7% and 31.6%, respectively. Genotype 3 was the next most prevalent (22.0%). Further, genotype 4, 2, and 5 were responsible for respectively 16.1%, 6.2%, and 1.9% of HCV infections. Genotype 6 and 7 comprise the remaining <1%. Throughout the years, a stable distribution was observed for most genotypes. Only for genotype 5, a decrease as a function of the year of analysis was observed, with respectively 3.6% for 2008, 2.3% for 2009 and 1.6% for the remaining years.

The overall M:F ratio was 1.59 and was mainly driven by the high M:F ratio of 3.03 for patients infected with genotype 3. Patients infected with genotype 3 are also younger (mean age 41.7 years) than patients infected with other genotypes (mean age above 50 years for all genotypes). The patients for whom a genotyping assay was performed in 2008 were younger than those from 2015.

Geographical distribution demonstrates that an important number of genotyped HCV patients live outside the Belgian metropolitan cities.

Conclusion

This national monitoring study allowed a clear and objective view of the circulating HCV genotypes in Belgium and will help health authorities in the establishment of cost effectiveness determinations before implementation of new treatment strategies.

This baseline characterization of the circulating genotypes is indispensable for a continuous surveillance, especially for the investigation of the possible impact of migration from endemic regions and prior to the increasing use of highly potent direct-acting antiviral (DAA) agents.

Prevalence and genotyping pattern of hepatitis C virus among patients on maintenance hemodialysis at five centers in Pune, India

Background

Worldwide prevalence of Hepatitis C virus (HCV) infection hemodialysis (HD) ranges from 1 to 84.6% with serious complications. Assessment of prevalence, risk factors, and genotyping of HCV infection in patient on HD was carried out at Pune, India.

Methods

A total of 250 patients on HD from five HD centers were recruited and tested for anti-HCV antibody using third-generation enzyme-linked immunosorbent assay (ELISA). Qualitative HCV RNA detection was carried out by nested reverse transcriptase polymerase chain reaction (RT-PCR). Genotyping and sequencing were carried out using the BigDye Terminator cycle sequencing ready reaction kit.

Results

Mean age of patients was 47.3 years. Forty-seven cases out of a total of 250 were reactor for HCV antibody. Overall prevalence rate was 18.8% ranging from 6.7% to 35.6% in the five centers. Of total, 44.1% of females and 13.5% of males were HCV infected. The mean duration of HD in HCV-infected patients was 6.03 years. Prevalence was higher in patients aged > 5 years on HD with higher number of blood transfusions. Thirty-six cases were positive for HCV RNA. Only one HCV RNA was detected among the 203 anti-HCV negative samples. Discordance between antibody and HCV RNA positivity was noted. Seventeen infected cases had changed dialysis centers four times. Thirteen cases were HBsAg positive, of which six cases were coinfected with HCV. Thirty-seven samples were genotyped.

Conclusion

The predominant genotype was 1a (54.1%) followed by 1b (43.2%) and 3a (2.7%). Highest prevalence of HCV (35.6%) and intracenter PNI of 99.3% of genotype 1b (84.6%) in center 3 indicates a possible nosocomial transmission.

Recombinant hepatitis C virus genotype 5a infectious cell culture systems expressing minimal JFH1 NS5B sequences permit polymerase inhibitor studies

The six major epidemiologically important hepatitis C virus (HCV) genotypes differ in global distribution and antiviral responses. Full-length infectious cell-culture adapted clones, the gold standard for HCV studies in vitro, are missing for genotypes 4 and 5. To address this challenge for genotype 5, we constructed a consensus full-length clone of strain SA13 (SA13fl), which was found non-viable in Huh7.5 cells. Step-wise adaptation of SA13fl-based recombinants, beginning with a virus encoding the NS5B-thumb domain and 3´UTR of JFH1 (SA13/JF372-X), resulted in a high-titer SA13 virus with only 41 JFH1-encoded NS5B-thumb residues (SA13/JF470-510cc); this required sixteen cell-culture adaptive substitutions within the SA13fl polyprotein and two 3´UTR-changes. SA13/JF372-X and SA13/JF470-510cc were equally sensitive to nucleoside polymerase inhibitors, including sofosbuvir, but showed differential sensitivity to inhibitors targeting the NS5B palm or thumb. SA13/JF470-510cc represents a model to elucidate the influence of HCV RNA elements on viral replication and map determinants of sensitivity to polymerase inhibitors.

Low prevalence of HCV infection with predominance of genotype 4 among HIV patients living in Libreville, Gabon

Background

Gabon is an endemic area for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) and the risk of co-infection is high.

Method

Between November 2015 and April 2016, we conducted retrospective study on HCV infection among people living with HIV/AIDS (PLHA). A total of 491 PLHA were included in this study and tested for the presence of HCV infection. HIV viral loads were obtained using the Generic HIV viral Load® assay and the CD4+ T cells count was performed using BD FACSCount™ CD4 reagents. HCV screening was performed using the MP Diagnostics HCV ELISA 4.0 kit. HCV genotypes were determined by sequence analysis of NS5B and Core regions. The Mann-Whitney test was used to compare the groups. Chi-2 test and Fisher's Exact Test were used to compare prevalence.

Results

HCV seroprevalence was 2.9% (14/491), (95% confidence interval (CI):1.4–4.3%). The percentage of HCV viremic patients, defined by the detection of HCV RNA in plasma, was 57% (8/14), representing 1.6% of the total population. HCV seroprevalence and replicative infection were not statistically differ with gender. The percentage of co-infection increased with age. No correlation with CD4+ T cells count and HIV viral load level was registered in this study. Identified HCV strains were predominantly of genotype 4 (87.5%) including 4k, 4e, 4g, 4p, 4f and 4c subtypes. Only one strain belonged to genotype 2 (subtype 2q). Analysis of the NS5B region did not reveal the presence of resistance-associated substitutions for sofosbuvir.

Conclusion

A systematic screening of hepatitis C is therefore strongly recommended as well as genotyping of HCV strains in order to adapt treatments for the specific case of people living with HIV/AIDS in Central Africa.

Demographic profile, host, disease & viral predictive factors of response in patients with chronic hepatitis C virus infection at a tertiary care hospital in north India

Background & objectives:

Standard of care for chronic hepatitis C (CHC) in India is peginterferon and ribavirin (RBV). The response to treatment in real life stetting is unclear. The objectives of this study were to evaluate the demographic profile and assess the virological response and predictors of response in CHC patients.

Methods:

Consecutive patients with CHC were included in this study. Detailed clinical history, risk factors, and predictive factors of response were noted. Patients were treated with peginterferon α2b (1.5 µg/kg/wk) and RBV (12 mg/kg/day) for 6 to 18 months based on response.

Results:

A total of 211 patients were included in the analysis, mean age 40.6±12.3 yr, 144 (68%) were males and 71 (34%) had compensated cirrhosis. Commonest risk factor for acquiring CHC was previous transfusion and surgery (51%). Genotype 3 (72%) was most common followed by genotype 1 (23%). Overall sustained virologic response (SVR) was 64 per cent [95% CI 57.1%-70.4%]. The SVR was 66.5 per cent [95% CI 58.34-73.89%] for genotype 3 and 61.2 per cent [95% CI 46.23 to 74.80%] for genotype 1. Non-cirrhotics had better SVR rates compared to cirrhotics (76 vs 41%, P<0.001). On multivariate analysis, BMI ≥23 kg/m², HOMA-IR ≥2, compliance (≤80%), and fibrosis >2 were predictors of low SVR.

Interpretation & conclusions:

Genotype 3 was the commonest HCV genotype. The commonest source of infection was previous transfusion and surgery. SVR rates for genotypes 3 were better than genotype 1 patients. Predictors of non-response were high BMI, insulin resistance, significant fibrosis and inadequate compliance.

Recombination in hepatitis C virus is not uncommon among people who inject drugs in Kolkata, India

Recombination in RNA virus is a rare event in the survival and evolution to evade host immune system. This is increasing within high risk group population (HRG) due to super infection that occurs by continuous sharing of common drug equipment by HCV infected or HIV-HCV co-infected recurrent drug users. Recombination causes impediment to vaccine development and therapeutic intervention as standard HCV treatment is still genotype specific. Blood samples of 194 people who inject drugs (PWID) were collected from an Opioid Substitution Therapy Centre in Kolkata, India. HCV sero-reactivity was checked by ELISA. Detection of HCV RNA by nested RT-PCR and genotyping by DNA sequencing were done. Phylogenetic analysis, Simplot, Bootscan plot, Recombination Detection Program were used for recombinant strain identification. Out of 80 HCV sero-reactive samples, 77 were RNA positive (96.25%). Out of 74 HIV mono-infected individuals, 12 HCV sero-nonreactive samples were HCV RNA positive. Out of total 89 RNA positive samples, 64 paired partial core and NS5B region (71.9%) were sequenced by Sanger's method. Two major genotypes (1 and 3), four subtypes and an inter-genotype recombinant strain (3a/1a) with a novel breakpoint in the NS4B coding region were found.

Genetic Diversity and Selective Pressure in Hepatitis C Virus Genotypes 1-6: Significance for Direct-Acting Antiviral Treatment and Drug Resistance

Treatment with pan-genotypic direct-acting antivirals, targeting different viral proteins, is the best option for clearing hepatitis C virus (HCV) infection in chronically infected patients. However, the diversity of the HCV genome is a major obstacle for the development of antiviral drugs, vaccines, and genotyping assays. In this large-scale analysis, genome-wide diversity and selective pressure was mapped, focusing on positions important for treatment, drug resistance, and resistance testing. A dataset of 1415 full-genome sequences, including genotypes 1-6 from the Los Alamos database, was analyzed. In 44% of all full-genome positions, the consensus amino acid was different for at least one genotype. Focusing on positions sharing the same consensus amino acid in all genotypes revealed that only 15% was defined as pan-genotypic highly conserved (≥99% amino acid identity) and an additional 24% as pan-genotypic conserved (≥95%). Despite its large genetic diversity, across all genotypes, codon positions were rarely identified to be positively selected (0.23%-0.46%) and predominantly found to be under negative selective pressure, suggesting mainly neutral evolution. For NS3, NS5A, and NS5B, respectively, 40% (6/15), 33% (3/9), and 14% (2/14) of the resistance-related positions harbored as consensus the amino acid variant related to resistance, potentially impeding treatment. For example, the NS3 variant 80K, conferring resistance to simeprevir used for treatment of HCV1 infected patients, was present in 39.3% of the HCV1a strains and 0.25% of HCV1b strains. Both NS5A variants 28M and 30S, known to be associated with resistance to the pan-genotypic drug daclatasvir, were found in a significant proportion of HCV4 strains (10.7%). NS5B variant 556G, known to confer resistance to non-nucleoside inhibitor dasabuvir, was observed in 8.4% of the HCV1b strains. Given the large HCV genetic diversity, sequencing efforts for resistance testing purposes may need to be genotype-specific or geographically tailored.

Correlation Study Between HCV Genotypes Distribution Pattern and Viral Load in a Tertiary Care Hospital in Kolkata, India

BACKGROUND

Hepatitis C virus infection is a leading cause for chronic liver disease. It has wide population specific genotype variability. Genotype knowledge and viral load assessment are equally important for designing therapeutic strategies and as predictors of treatment outcome among hepatitis C (HCV) infected patients.

MATERIALS AND METHODS

Between June 2012 and 2013 an observational study was conducted among 350 chronic hepatitis patients visiting Calcutta National Medical College, Kolkata, India. Among them, 110 anti-HCV antibody positive cases were diagnosed and subjected to viral RNA extraction, viral genotyping and viral load quantification using polymerase chain reaction (PCR) based techniques.

STATISTICAL ANALYSIS

Statistical analysis was done with IBM SPSS Statistics software, version 20. p-value <0.05 was regarded as statically significant.

RESULTS

Among 66 HCV RNA positive cases, genotypes 1a, 3a and 3b were observed among 18 (27%), 44(67%) and 4(6%) cases respectively. Genotype 3a had higher viral load than patients infected with genotypes 1and 3b. However, no statistical significance was observed for viral load among the various HCV RNA genotypes.

CONCLUSION

Genotype 3a accounted for the highest number of cases with positive HCV RNA. However, no statistically significant difference existed for viral load among the various HCV RNA genotypes in this study.

Usefulness of a fourth generation ELISA assay for the reliable identification of HCV infection in HIV-positive adults from Gabon (Central Africa)

Background/Objectives

Guidelines for optimized HCV screening are urgently required in Africa, especially for patients infected with HIV, who sometimes show false positive or false negative reactivity in anti-HCV antibody assays. Here, we assessed the usefulness of a fourth-generation HCV Ag-Ab ELISA for the identification of active HCV infection in HIV-positive patients.

Methods

This cross-sectional study was conducted between 03/2010 and 01/2013 and included 762 Gabonese HIV-positive adult patients. The results of ELISA (Monolisa HCV Ag-Ab ULTRA, Bio-Rad) were compared with those obtained by RT-PCR (gold standard). The optimal ELISA signal-to-cutoff (S/CO) ratio to identify patients with active hepatitis C (positive HCV RNA) was determined. Specimens were further tested by the INNO-LIA HCV Score assay (Innogenetics) and the Architect HCV Ag kit (Abbott) to define the best diagnostic strategy.

Results

Sixty-seven patients tested positive for HCV (S/CO ratio ≥ 1) by ELISA. Of these, 47 (70.1%) tested positive for HCV RNA. The optimal S/CO associated with active HCV infection was 1.7. At this threshold, the sensitivity of ELISA was 97.9% (95% confidence interval (CI) 90.0–99.9%), its specificity was 91.3% (95% CI 85.0–95.5%), and HCV seroprevalence rate was 7.3% (56/762) (95% CI 5.6–9.4%). Among 57 HCV-seropositive patients with available INNO-LIA results, false reactivity was identified in 14 (24.6%), resolved HCV infection in two (3.5%), possible acute HCV infections in nine (15.8%) and likely chronic HCV infections in 32 (56.1%) patients. HCV core Ag was undetectable in 14/15 (93.3%) specimens that tested negative for HCV RNA whereas it was quantified in 34 (out of 39, 87.2%) samples that tested positive for HCV RNA.

Conclusions

Our study provides comprehensive guidance for HCV testing in Gabon, and will help greatly clinicians to improve case definitions for both the notification and surveillance of HCV in patients co-infected with HIV.

A novel nested reverse-transcriptase polymerase chain reaction method for rapid hepatitis C virus detection and genotyping

PURPOSE

Rapid and specific detection of viral nucleic acid is increasingly important in the diagnosis of infectious diseases. The objective was to develop a rapid, efficient process of nucleic acid based detection of hepatitis C virus (HCV) infection for its diagnosis and treatment follow-up.

MATERIALS AND METHODS

A two-step nested reverse-transcriptase polymerase chain reaction (RT-PCR) has been standardised on a sample set of 125 individuals from different liver clinics in Kolkata. The method utilises a novel fast nested RT-PCR for HCV detection and genotyping from HCV infected patient plasma with high processivity.

RESULTS

The overall time required from ribonucleic acid (RNA) isolation to nested PCR amplified product detection is reduced to 42% when compared with conventional nested RT-PCR amplification. The method is sensitive as conventional PCR and detected all HCV RNA positive samples. Sequencing, phylogenetic analysis of the PCR amplified product by this method showed concordant genotypes with conventional PCR.

CONCLUSION

Though being a two-step process, this method is fast, cost-efficient, reliable and feasible for regular HCV RNA screening and apt even in resource limited settings. This method could be translated to regular nucleic acid screening for other infectious diseases as regular PCR regimen.

Transmission dynamics of hepatitis C virus among intra venous drug users in the border state of Manipur, India

Intra venous drug users (IVDUs) are at high risk for hepatitis C virus (HCV) infection owing to their high rate of drug abuses. The north-eastern part of India has a high prevalence of IVDUs with Manipur being the worst hit state. The aim of the study was to document the molecular epidemiology, the patterns of HCV transmission, genomic variation and recombination events within HCV genome among IVDUs of Manipur, India. 91 anti-HCV sero-reactive blood samples were collected from IVDUs in Manipur. The samples were processed for RNA extraction, nested RT-PCR, sequencing and quantitative viral RNA estimation. Phylogeographic analysis of the sequenced core and NS5B regions of HCV genome was performed to determine the probable transmission route and recombinant HCV strains. 83 out of 91 anti-HCV seropositive samples were RNA positive (91.20%) based on 5'UTR of HCV genome by nested RT-PCR. Of the RNA positive samples, 73 paired partial core and NS5B gene were sequenced. Three major genotype and eight subtypes were detected while no recombinant strains were found. Individuals with genotype 1 had the mean viral load (5.94 ± 0.705 log10IU/ml) followed by genotype 3 (4.91 ± 0.49 log10IU/ml) and 6 (3.96 ± 0.32 log10IU/ml). The viral load was statistically significant among the male individuals at 4.822 ± 1.36 log10IU/ml compared to 4.767 ± 0.49 log10IU/ml for females (t=3.249, p<0.005). The phylogeographic results indicated 3b, 6h originated from Vietnam, 1a had Indian origin, 3a, 6k originated from southern China while 1b originated from Myanmar, respectively. The incidence of eight different subtypes in Manipur reflects the transmission of these strains from the "Golden Triangle" drug trafficking regions. Sequence analysis confirmed the transmission routes of HCV, which is linked to China and Vietnam for the newly emergent genotype 6 in north-eastern India.

Prevalence of hepatitis A virus, hepatitis B virus, hepatitis C virus, hepatitis D virus and hepatitis E virus as causes of acute viral hepatitis in North India: a hospital based study

CONTEXT

Acute viral hepatitis (AVH) is a major public health problem and is an important cause of morbidity and mortality.

AIM

The aim of the present study is to determine the prevalence of hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV) and hepatitis E virus (HEV) as causes of AVH in a tertiary care hospital of North India.

SETTINGS AND DESIGN

Blood samples and clinical information was collected from cases of AVH referred to the Grade I viral diagnostic laboratory over a 1-year period.

SUBJECTS AND METHODS

Samples were tested for hepatitis B surface antigen, anti-HCV total antibodies, anti-HAV immunoglobulin M (IgM) and anti-HEV IgM by the enzyme-linked immunosorbent assay. PCR for nucleic acid detection of HBV and HCV was also carried out. Those positive for HBV infection were tested for anti-HDV antibodies.

STATISTICAL ANALYSIS USED

Fisher's exact test was used and a P < 0.05 was considered to be statistically significant.

RESULTS

Of the 267 viral hepatitis cases, 62 (23.22%) patients presented as acute hepatic failure. HAV (26.96%) was identified as the most common cause of acute hepatitis followed by HEV (17.97%), HBV (16.10%) and HCV (11.98%). Co-infections with more than one virus were present in 34 cases; HAV-HEV co-infection being the most common. HEV was the most important cause of acute hepatic failure followed by co-infection with HAV and HEV. An indication towards epidemiological shift of HAV infection from children to adults with a rise in HAV prevalence was seen.

CONCLUSIONS

To the best of our knowledge, this is the first report indicating epidemiological shift of HAV in Uttar Pradesh.

Rapid immunoassay alone is insufficient for the detection of hepatitis C virus infection among high-risk population

Rapid testing for HCV has become a routine practice in resource-limited settings for initial screening. The objective of this study was to evaluate the performance of rapid immunoassay diagnostic test kits for specific and accurate diagnosis of HCV infection among different patient groups in clinical settings of Kolkata, India. Two hundred and fifty-four randomly selected serum samples of 612 samples reported as HCV nonreactive by rapid immunodiagnostic tests were evaluated for HCV antibody, ELISA and HCV RNA testing for confirmatory diagnosis. 15.74% were HCV seropositive by ELISA, and 11.02% were RNA positive by nested RT-PCR. Additionally, 15 HCV-seronegative chronic liver disease patients with high ALT and AST values were screened for HCV RNA, of which five were positive whose viral load ranged from 1.2 × 10(2) to 4.4 × 10(6) IU/mL, and the samples belonged to IVDUs and HIV-co-infected individuals. The results showed that HCV rapid immunoassay test cannot be solely relied on as an absolute and accurate diagnostic tool for screening infection of HCV particularly in high-risk group patients such as IVDUs, haemodialysis, thalassaemic and HIV-co-infected patients who need HCV screening frequently.

HCV genotype determination in monoinfected and HIV co-infected patients in Cuba

With the aim to characterize the HCV genotype distribution in Cuba, sera were collected from two subgroups: HCV-monoinfected and HCV/HIV co-infected patients. A combination of reverse transcription-PCR using genotype-specific primers, restriction fragment length polymorphism and sequencing was used to determine the genotype of 84 samples. Seventy-nine (94%) showed single infections (10 [12%] were genotype 1a and 69 [82%] genotype 1b) and 5 (6%) samples corresponded to mixed infections (2 [2%] with genotypes 1a/3a and 1 sample [1%] each with 1b/3a, 1b/4a and 1a/1b/3a). HCV/HIV co-infected subjects had a higher frequency of mixed infections (p=0.08), infection with genotype 3a (p=0.18) and for the first time genotype 4a was found. There was no association of any demographic characteristics with any specific genotype although HCV/HIV co-infected patients showed a tendency to have mixed genotypes in those older than 45 years of age (p=0.11). Phylogenetic analysis showed that HCV isolates clustered with subtypes 1b (n=15, maximal genetic distance 2.51%) and 1a (n=2, maximal genetic distance 0.35%). This report presents the prevalence of HCV genotypes in monoinfected and HIV co-infected patients, mixed HCV infections in HCV/HIV co-infected men who have sex with men with high-risk sexual practices and for the first time identifies that the uncommon genotype 4a can be present in a patient co-infected with HIV.

[World constructed by self-organization of some amphiphils--with a focus on vesicle formation--]

The world constructed by self-organization of some amphiphils was discussed on the basis of micelle formation, vesicle formation, and oriented-nano-wire formation. First, the micelle formation of a both water- and oil- soluble surfactant, Aerosol OT, was discussed. Solution states of micelles and monomer were discussed on the basis of thermodinamic and NMR spectroscopic analyses of micelle formation. Next, micelle-vesicle transition was discussed. It was proposed that the phospholipid LUV formation by removing detergents and destruction by adding detergents occurred via 4 stages. The 4 stage model instead of the 3 stage model could not only elucidate the complicated phenomena observed during micelle-vesicle transition, but predicted the size and properties of the vesicles formed by detergent removal from mixed micelles. Next, the vesicle formation of a fatty acid with a single hydrophobic chain different from phospholipid, which has two hydorophobic chains, was discussed. The vesicle formation was strongly affected by the presence of preformed vesicles and the size was biased on the preformed vesicles. It was shown there exist two pass ways in the process of micelle-vesicle transition by pH jump. One is fission of the preformed vesicles after transfer of monomers from newly added oleate micelles and the other is transition from the mixed micelles after partial solubilization by the oreate micelles. Then, the vesicle formation of HCO-10, which has 3 hydrophobic chains, the mixed vesicle formation of phosphatidylethanolamine and lysophosphtidylcholine, which can not form vesicles, and the phospholipid vesicle formation and destruction by removing and adding PEG-lipid, were discussed. Lastly, oriented nano wire formation of mulamyldipeptid-conjugated lipids with ca 5 nm of diameter was discussed.

Treatment of Chronic Hepatitis due to Hepatitis C Virus (CH-C) in India: A Randomized Controlled Trial Comparing Daily Interferon-alfa-2b and Ribavirin with Daily Interferon-alfa-2b and Glycyrrhizin-A Multicenter Study

BACKGROUND AND AIM

Pegylated-interferon-alfa (PEG-IFN-α) with ribavirin is an established treatment in chronic hepatitis due to hepatitis C virus (HCV) (CH-C). Such treatment is expensive and in resource-poor countries such as India, alternative less expensive therapy is needed.

METHODS

Multicenter randomized controlled trial comparing two treatment regimens (interferon-alfa-2b [IFN-α-2b] 3 million unit/day [MU/day] and ribavirin 1000 mg/day [I+R] vs IFN-α-2b 3 MU/day and glycyrrhizin 250 mg [I+G]) in CH-C. Viral, host characteristics and therapeutic responses were assessed (ICMR-6 months trial for chronic hepatitis-CTRI/2008/091/000105).

RESULTS

One hundred and thirty-one patients meeting the inclusion criteria were randomized to I + G (n=64) or I+R (n=67) during the period February 2002 to May 2005. About 85% (I+G=53, I+R=58) completed 6 months of treatment and 89% of them (I+G=46, I+R=53) completed 6 months of follow-up after completion of treatment. Hepatitis C virus genotype 3 was the major type detected (71% patients). The mean log10 viral load (copies/mL), histological activity index, and fibrosis stage for all patients were 5.1 ± 0.98, 5 ± 2, and 2± 1.5, respectively. Sustained viral response (SVR) was significantly higher in I + R group than in I + G group (65.7% vs 46.9%, OR=2.2, P = 0.03). Treatment with I + G was associated with significantly lower frequencies of leukopenia (2% vs 17%, P <0.01) and anemia (8% vs 40%, P <0.001) as compared to treatment with I + R.

CONCLUSION

Genotype 3 HCV infection with low viral load is prevalent in India. Daily IFN with ribavirin showed significantly better responses. Leukopenia and anemia were significantly more in ribavirin group. Responses observed with IFN + ribavirin were similar to the reported response rates with PEG-IFN suggesting that this modality may be considered as a cheaper alternative of treatment for chronic hepatitis C.

Recent pattern of Co-infection amongst HIV seropositive individuals in tertiary care hospital, Kolkata

BACKGROUND

Opportunistic Infections (OIs) and co-infections are the major cause of deaths amongst HIV infected individuals and this mostly depends upon the risk factors, type of exposure and geographic region. The commonest types of infections reported are tuberculosis, chronic diarrhoea, oral candidiasis, herpes simplex virus-2, cytomegalovirus, hepatitis B virus and hepatitis C virus. Due to the scarcity of OIs data available from this region, we had designed a study to determine the frequency of different OIs amongst HIV seropositive patients.

METHODS

Analysis of the different spectrum of OIs/Co-infections were carried out with 204 HIV sero-positive patients (142 males and 62 females) who visited the HIV/AIDS Apex Clinic in a tertiary care hospital from March 2006 to March 2009. The CD4+ count was estimated using FACS Calibur, the routine smear test, serology, nested RT-PCR and DNA sequencing were carried out to determine the different OIs.

RESULTS

In this study, HIV seropositive patients were mostly from middle age group (31-40 yrs) with CD4+ counts in majority of symptomatic AIDS patients below 200 cells/mm3. The common co-infections/opportunistic infections were OC (53.43%), CD (47.05%), HSV-2 (36.76%), TB (35.29%), CMV (26.96%), HBV (15.19%) and HCV (7.35%). Dual infections, like HSV-2 & CMV (15.38%), HSV-2 & TB (14.61%), HSV-2 & oral candidiasis (24.61%) and CMV & oral candidiasis (14.61%) were significant in follow-up patients. Triple infections were also common e.g., TB, CD, OC infection occurring frequently in about 14.21% of the study population. Multiple infections like OC, TB, CD amongst the viral co-infected patients with HSV-2, HCV, CMV and HBV are also reported in this study. The genotyping analysis of the HCV co-infected HIV individuals shows that two belonged to HCV genotype 1 and 8 belonged to genotype 3.

CONCLUSIONS

A wide spectrum of OIs were observed amongst HIV-infected patients in the HIV/AIDS Apex Clinic. Oral candidiasis, CD, CMV and HSV-2, were the common OIs in those patients. This study aims to provide a clearer picture regarding infections occurring amongst HIV seropositive individuals so that the scientific findings could be translated into sustainable prevention programmes and improved public health policies.

TRIAL REGISTRATION

None.

Serial measurements of hepatitis C viral load by real-time polymerase chain reaction among recipients of living-donor renal transplants: a short-term follow-up study from a single center

There is a high prevalence of hepatitis C virus (HCV) infection among immunosuppressed patients including renal transplant recipients. The study investigated serum viral loads for up to 6 months posttransplantation among these patients. Serum viral load was serially monitored using real-time polymerase chain reaction (PCR) in 25 HCV-positive renal transplant recipients pretransplantation as well as day 10 and 6 months posttransplantation. A liver biopsy specimen obtained under vision at the time of transplantation was analyzed for viral load as well as for histological changes. There was increased viremia at day 10 followed by a significant (2 log) reduction at 6 months posttransplantation. Pretransplantation serum and intrahepatic viral load showed significant positive correlations (r = 0.727; P = .001), the latter also reflecting liver fibrosis score (r = 0.423; P = .05). The findings suggested that serum viral load reflects intrahepatic viral load, which in turn correlates with liver fibrosis. At 6 months posttransplantation, the modulatory effects of immunosuppressive drugs and of the host immune response may lead to a reduced viral load.

Hepatitis C virus infection may lead to slower emergence of P. falciparum in blood

Background

Areas endemic for Plasmodium falciparum, hepatitis B virus (HBV) and hepatitis C virus (HCV) overlap in many parts of sub-Saharan Africa. HBV and HCV infections develop in the liver, where takes place the first development stage of P. falciparum before its further spread in blood. The complex mechanisms involved in the development of hepatitis may potentially influence the development of the liver stage of malaria parasites. Understanding the molecular mechanisms of these interactions could provide new pathophysiological insights for treatment strategies in Malaria.

Methodology

We studied a cohort of 319 individuals living in a village where the three infections are prevalent. The patients were initially given a curative antimalarial treatment and were then monitored for the emergence of asexual P. falciparum forms in blood, fortnightly for one year, by microscopy and polymerase chain reaction.

Principal Findings

At inclusion, 65 (20.4%) subjects had detectable malaria parasites in blood, 36 (11.3%) were HBV chronic carriers, and 61 (18.9%) were HCV chronic carriers. During follow-up, asexual P. falciparum forms were detected in the blood of 203 patients. The median time to P. falciparum emergence in blood was respectively 140 and 120 days in HBV- and HBV+ individuals, and 135 and 224 days in HCV- and HCV+ individuals. HCV carriage was associated with delayed emergence of asexual P. falciparum forms in blood relative to patients without HCV infection.

Conclusions

This pilot study represents first tentative evidence of a potential epidemiological interaction between HBV, HCV and P. falciparum infections. Age is an important confounding factor in this setting however multivariate analysis points to an interaction between P. falciparum and HCV at the hepatic level with a slower emergence of P. falciparum in HCV chronic carriers. More in depth analysis are necessary to unravel the basis of hepatic interactions between these two pathogens, which could help in identifying new therapeutic approaches against malaria.

Pathogenesis of hepatitis E virus and hepatitis C virus in chimpanzees: similarities and differences

The chimpanzee is the only animal model for investigating the pathogenesis of viral hepatitis types A through E in humans. Studies of the host response, including microarray analyses, have relied on the close relationship between these two primate species: chimpanzee samples are commonly tested with human-based reagents. In this study, the host responses to two dissimilar viruses, hepatitis E virus (HEV) and hepatitis C virus (HCV), were compared in multiple experimentally infected chimpanzees. Affymetrix U133+2.0 human microarray chips were used to assess the entire transcriptome in serial liver biopsies obtained over the course of the infections. Respecting the limitations of microarray probes designed for human target transcripts to effectively assay chimpanzee transcripts, we conducted probe-level analysis of the microarray data in conjunction with a custom mapping of the probe sequences to the most recent human and chimpanzee genome sequences. Time points for statistical comparison were chosen based on independently measured viremia levels. Regardless of the viral infection, the alignment of differentially expressed genes to the human genome sequence resulted in a larger number of genes being identified when compared with alignment to the chimpanzee genome sequence. This probably reflects the lesser refinement of gene annotation for chimpanzees. In general, the two viruses demonstrated very distinct temporal changes in host response genes, although both RNA viruses induced genes that were involved in many of the same biological systems, including interferon-induced genes. The host response to HCV infection was more robust in the magnitude and number of differentially expressed genes compared to HEV infection.

Complete genome sequences of hepatitis C virus subtype 3i and 3a subtype isolates from India

AIM

Hepatitis C virus (HCV), a major causative agent of chronic hepatitis, is classified into six major genotypes. Genotype 3 HCV infection is more sensitive to interferon therapy. In India, genotype 3, particularly subtype 3a, HCV infections are common. Three novel HCV subtypes i.e., 3g, 3j, and 3i were identified from India based on partial genomic sequences. This report provides full genome sequences of one isolate each of subtypes 3i and 3a.

METHODS

Serum samples positive for subtype 3i and 3a HCV RNA based on core region genomic sequences were studied. Complete HCV genomes were amplified as 11 overlapping PCR fragments and sequenced.

RESULTS

The complete genomic sequence of Indian HCV 3i isolate clustered with other genotype 3 sequences, and was closer to subtypes 3b and 3a (80.5% and 79.1% [SD 0.4%] nucleotide identity). Nucleotide similarities were the highest in the core region (86.1-88.7%), and the least in the E2 region (69.4-70.7%). Phylogenetic tree analysis confirmed the existence of a separate subtype 3i. The Indian HCV 3a isolate's complete genomic sequences clustered with previously known genotype 3a sequences with a nucleotide similarity of 91.1% (SD 0.2%). Neither isolates showed evidence of recombination of different HCV genotypes.

CONCLUSION

The information on complete genomic sequences of the genotype 3 HCV isolates should be helpful in future studies on HCV evolution and classification, and for development of newer therapeutic and preventive strategies against this infection.

Primary hepatocyte culture supports hepatitis C virus replication: a model for infection-associated hepatocarcinogenesis

Analysis of progressive changes in hepatic gene expression that underlie hepatocarcinogenesis following hepatitis C virus (HCV) infection require examination of long-term cultures of normally differentiating primary human hepatocytes. We report a culture system of primary hepatocytes that support productive replication of infectious HCV. Hepatic functions were analyzed by reverse-transcription polymerase chain reaction amplification of total cell RNA from cultures maintained in serum-free defined medium for up to 190 days. Sustained hepatic function was assessed by expression of albumin, alpha-fetoprotein, cytochrome P4502E1, cytokeratin-18, type-1 collagen, transforming growth factor-beta 1, matrix metalloproteinase-2 (MMP-2), MMP-13, and interferon alpha-receptors 1 and 2. Normally differentiated human primary hepatocytes supported productive replication of infectious clones of HCV genotypes 1a, 1b, and 2a; virus infection was inhibited by antibodies against CD81 virus entry factor. Virus released into the culture media of HCV-infected primary hepatocytes repeatedly passage to naïve hepatocytes. Replication of the three HCV genotypes shows interferon sensitivity observed in natural infections.

CONCLUSION

Sustained cultures of physiologic host cells for the propagation of infectious HCV strains should accelerate studies of host response to HCV infection and progressive liver disease.

HCV antibody response and genotype distribution in different areas and races of China

Hepatitis C virus (HCV) heterogeneity accounts for the failure of effective vaccine development and the lack of successful anti-viral therapy in some patients. Little is known about the immune response to HCV peptides and the region or race specific genotypes in China. The objective of this study was to characterize HCV antibody immune response to HCV peptides and HCV genotypes in different regions and races of China. A total of 363 serum samples were collected from HCV carriers in 6 regions in China. The immune response to HCV peptides was evaluated by ELISA. HCV genotypes were examined using nested RT-PCR. We found that the anti-HCV antibody neutralization rates were significantly different among the serum samples from different areas or from different races in the same area. For samples from Tibet and Sinkiang, the rates of neutralization by HCV peptides were only 3.2% and 30.8%, respectively. The genotypes of samples from Tibet and Sinkiang were apparently heterogeneic and included type I, II, III and multiple types (I/II/III, I/II, I/III, II/III). One specific sample with multiple-genotype (I/II/III) HCV infection was found to consist of type I, II, III, II/III and an unclassified genotype. These studies indicate that the anti-HCV antibody immune response to HCV peptides varied across regions and among races. The distribution of HCV genotypes among Tibetans in Tibet and Uighurs in Sinkiang was different from that in the inner areas of China. In addition, a "master" genotype, type II, was found to exist in HCV infection with multiple HCV genotypes.

High prevalence of hepatitis C virus infection and predominance of genotype 4 in rural Gabon

Hepatitis C (HCV) molecular epidemiology is documented poorly in central African countries. In response to this, a population-based study of 319 consenting adults resident in a remote village of Gabon was undertaken (mean age: 38 years; age range: 13-85+; sex ratio: 0.74). Screening for anti-HCV antibodies was performed using ELISA and recombinant immunoblot assay. Seropositive samples were assessed further with viral load and genotyping techniques. Sixty-six (20.7%) individuals were HCV seropositive. Viral loads ranged from 600 to 24.9 million IU/ml (median: 372,500). Seroprevalence and viral loads increased significantly with age (P < 10(-5) and P < 0.003, respectively). HCV sequences of the 5'UTR genome region were obtained from 60 (90.9%) samples and NS5B region sequences were obtained from 22 (36.6%) samples. All strains belonged to subtypes of genotype 4: 4e (72.7%), 4c (13.6%), 4p (4.5%), 4r (4.5%) and one unclassified genotype 4 strain. Evolutionary analysis of the subtype 4e sequences indicates a period of raised transmission during the early twentieth century.

Hepatitis C virus prevalence and genetic diversity among pregnant women in Gabon, central Africa

Background

Hepatitis C virus (HCV) infection is a major global public health problem in both developed and developing countries. The prevalence and genetic diversity of HCV in pregnant women in Gabon, central Africa, is not known. We therefore evaluated the prevalence and the circulating genotypes of HCV in a large population cohort of pregnant women.

Methods

Blood samples (947) were collected from pregnant women in the five main cities of the country. The prevalence was evaluated by two ELISA tests, and the circulating genotypes were characterized by sequencing and phylogenetic analysis.

Results

Twenty pregnant women (2.1%) were infected with HCV. The seroprevalence differed significantly by region (p = 0.004) and increased significantly with age (p = 0.05), being 1.3% at 14–20 years, 1.1% at 21–25 years, 1.9% at 26–30 years, 4.1% at 31–35 years and 6.0% at > 35 years. Sequencing in the 5'-UTR and NS5B regions showed that the circulating strains belonged to genotypes 4 (4e and 4c).

Conclusion

We found that the HCV seroprevalence in pregnant women in Gabon is almost as high as that in other African countries and increases with age. Furthermore, only genotype 4 (4e and 4c) was found. More extensive studies aiming to evaluate the prevalence and heterogeneity of HCV genotypes circulating in the general population of the country are needed.

Development of a TaqMan assay for the six major genotypes of hepatitis C virus: comparison with commercial assays

A quantitative real-time PCR assay was developed that detects genomic RNA from reference strains representing the six major genotypes of hepatitis C virus (HCV) with equal sensitivity and accurately measured HCV RNA in JFH1 HCV-infected Huh7.5 cells. The method is indirectly calibrated to the first international (WHO 96/790) HCV standard preparation and has a linear dynamic range of 10(2.6)-10(6.5) IU/ml. In addition, the inter- and intra-assay precision were approximately 3% CV and <2% CV, respectively. Comparison with results obtained by commercially available HCV RNA Nucleic Acid Technology kits (Versant HCV RNA 3.0 b-DNA and Amplicor HCV Monitor), that also employ the WHO standard, allowed validation of the TaqMan assay against all major HCV genotypes. Both commercial methods detected HCV RNA over a wide dynamic range, but showed a consistent difference of about 0.3 log10 when evaluating samples of different HCV genotypes. The genome titers obtained with the three methods correlated with the infectivity titers previously determined for the HCV reference strains. TaqMan assays have become an essential tool to follow viral load in clinical samples and cell culture-based experiments and this technology offers significant advantages in linear dynamic range, sensitivity and customization.

Structure and functions of hepatitis C virus proteins: 15 years after

Since its discovery in 1988, the hepatitis C virus (HCV) has become a hot topic of research by many groups around the world. This globally spread infectious agent is responsible for a large proportion of chronic viral hepatitides. The clue to halting the hepatitis C pandemic may be the detailed understanding of the virus structure, its replication mechanism, and the exact functions of the various proteins. Such understanding could enable the development of new antivirals targeted against hepatitis C virus and possibly an effective vaccine. This review recaps the current knowledge about the HCV genome 15 years after its discovery. The structure and function of particular viral structural (core, E1, E2) and nonstructural (NS2, NS3, NS4, NS5) proteins and noncoding regions known to date are described. With respect to frequent conflicting reports from different research groups, results reproducibly demonstrated by independent investigators are emphasized. Owing to many obstacles and limitations inherent in doing research on this noteworthy virus, the current knowledge is incomplete and the answers to many important questions are to be expected in the future.

Multicenter study on hepatitis C virus-related cryoglobulinemic glomerulonephritis

BACKGROUND

Mixed cryoglobulinemia is a multisystem disorder associated strongly with hepatitis C virus (HCV) infection. The kidney frequently is involved, and glomerulonephritis represents the key factor affecting prognosis.

METHODS

Clinical, serological, immunogenetic, and morphological data were collected retrospectively from medical records of 146 patients with cryoglobulinemic glomerulonephritis who underwent biopsies in 25 Italian centers and 34 cryoglobulinemic controls without renal involvement.

RESULTS

Eighty-seven percent of patients were infected with HCV; genotype 1b was more frequent than genotype 2 (55% versus 43%). Diffuse membranoproliferative glomerulonephritis was the most prevalent histological pattern (83%). Type II cryoglobulin (immunoglobulin Mkappa [IgMkappa]/IgG) was detected in 74.4% of cases. The remainder had type III (polyclonal IgM/IgG) cryoglobulins. A multivariate Cox proportional hazard model showed that age, serum creatinine level, and proteinuria at the onset of renal disease were associated independently with risk for developing severe renal failure at follow-up. Overall survival at 10 years was about 80%. Kaplan-Meier survival curves were worsened by a basal creatinine value greater than 1.5 mg/dL (>133 mumol/L), but were unaffected by sex and HCV infection. Cardiovascular disease was the cause of death in more than 60% of patients.

CONCLUSION

Data confirm the close association between mixed cryoglobulinemia and HCV infection and between glomerulonephritis and type II cryoglobulin. Survival profiles are better than previously reported in the literature, probably because of improvement in therapeutic regimens. Causes of death reflect this improvement in survival, with an increased prevalence of cardiovascular events compared with infectious complications and hepatic failure, which were predominant in the past.

The phylogenetic analysis of hepatitis C virus isolates obtained from two Iranian carriers revealed evidence for a new subtype of HCV genotype 3

Classification of hepatitis C virus is based on phylogenetic analysis of the strains reported world wide. Different strains are classified within 6 major genotypes and several minor groups (subtypes). In addition to epidemiologic value of determining genotype/subtype of this virus, the result may change the therapeutic strategy used for a patient. During a survey on hepatitis C in Iran, we found two cases assigned as 1b genotype by PCR-RFLP on 5' UTR, but three based on core region sequencing. Fragments from 5' UTR, Core and NS5b regions were PCR-amplified and sequenced followed by phylogenetic analysis. Although the 5' UTR of this new strain is very similar to genotypes 1 and 6, analysis of core region classifies it in a separate branch of genotype 3, close to subtypes h and k. Further analysis of NS5b region put this new strain in a separate branch near other subtypes of genotype 3 and 4. These data are suggestive of a new subtype within genotype 3.

Whole recombinant yeast-based immunotherapy induces potent T cell responses targeting HCV NS3 and Core proteins

Control of primary infection with hepatitis C virus (HCV) is associated with robust and broad T cell immunity. In contrast, chronic infection is characterized by weak T cell responses suggesting that an approach that boosts these responses could be a therapeutic advance. Saccharomyces cerevisiae is an effective inducer of innate and adaptive cellular immunity and we have generated recombinant yeast cells (GI-5005) that produce an HCV NS3-Core fusion protein. Pre-clinical studies in mice showed that GI-5005 induced potent antigen-specific proliferative and cytotoxic T cell responses that were associated with Th1-type cytokine secretion. In studies in which GI-5005 was administered up to 13 times, no detectable vector neutralization or induction of tolerance was observed. Prophylactic as well as therapeutic administration of GI-5005 in mice led to eradication of tumor cells expressing HCV NS3 protein. Immunotherapy with GI-5005 is being evaluated in chronic HCV infected individuals in a Phase 1 clinical trial.

Distribution of HCV genotypes in patients with end-stage renal disease according to type of dialysis treatment

The objective of this study was to investigate the effects of types of dialysis treatments on hepatitis C virus infection and the epidemiologic properties of hepatitis C virus (HCV) infection at three Baskent University hospitals, in Ankara, Adana, and Izmir, Turkey, in 655, 326, and 118 patients with end-stage renal disease, respectively. One hundred thirty patients with HCV viremia among 271 patients with end-stage renal disease seropositive for HCV were included in this cross-sectional study. HCV RNA-positive patients were classified according to the renal replacement therapies (hemodialysis or continuous ambulatory peritoneal dialysis), and viral load, transaminase levels, and distribution of genotypes were compared between these subgroups. In the continuous ambulatory peritoneal dialysis group, 26 of 165 patients (16%) were serum anti-HCV positive, and 11 of 26 patients (42%) were serum HCV RNA positive. Twenty-six percent of the patients undergoing hemodialysis were anti-HCV positive, and 49% were HCV RNA positive. The prevalence of genotype 1b was 68% and 73% for patients in the continuous ambulatory peritoneal dialysis and hemodialysis groups, respectively. No significant differences were found between the genotype 1b and the non-1b groups or between different dialysis types with regard to age and sex and serum aspartate transaminase, alanine aminotransferase, and HCV RNA levels. We conclude that HCV seropositivity may differ between different types of dialysis treatments, although viral load and genotypes may be similar in persons with end-stage renal disease and those without.

Transmission of human hepatitis C virus from patients in secondary cells for long term culture

Infection by human hepatitis C virus (HCV) is the principal cause of post-transfusion hepatitis and chronic liver diseases worldwide. A reliable in vitro culture system for the isolation and analysis of this virus is not currently available, and, as a consequence, HCV pathogenesis is poorly understood. We report here the first robust in vitro system for the isolation and propagation of HCV from infected donor blood. This system involves infecting freshly prepared macrophages with HCV and then transmission of macrophage-adapted virus into freshly immortalized B-cells from human fetal cord blood. Using this system, newly isolated HCV have been replicated in vitro in continuous cultures for over 130 weeks. These isolates were also transmitted by cell-free methods into different cell types, including B-cells, T-cells and neuronal precursor cells. These secondarily infected cells also produced in vitro transmissible infectious virus. Replication of HCV-RNA was validated by RT-PCR analysis and by in situ hybridization. Although nucleic acid sequencing of the HCV isolate reported here indicates that the isolate is probably of type 1a, other HCV types have also been isolated using this system. Western blot analysis shows the synthesis of major HCV structural proteins. We present here, for the first time, a method for productively growing HCV in vitro for prolonged periods of time. This method allows studies related to understanding the replication process, viral pathogenesis, and the development of anti-HCV drugs and vaccines.

Hepatitis C virus (HCV) 5′NC sequence variants and their association with hepatitis C risk groups

BACKGROUND

Genotype distribution of hepatitis C virus (HCV) is relatively uniform in Prague, Czech Republic. Unlike the other developed countries where HCV genotype 3 is increasingly associated with injection drug users (IDU), subtype 1b remains the most prevalent HCV subtype in Prague, regardless of risk factors.

OBJECTIVE

We wished to determine if subtype 1b strains could be further differentiated by comparing the conserved 5'NC sequences of the strains infecting IDU and non-IDU populations.

STUDY DESIGN

All prospectively collected serum samples that were HCV RNA positive were genotyped according to the 5'NC and NS5b regions. All 5'NC sequences were further analyzed for new mutations and these data were compared to patient epidemiologic information.

RESULTS

We found eight 5'NC sequence variants among 96 specimens tested. Further analysis of subtype 1b strains showed that a variant with a nucleotide insertion at -138 positions was found only among non-IDU subjects, while the variant with T-->C substitution at -94 was found only among the IDUs.

CONCLUSIONS

These observations suggest that the current HCV transmission between the IDU and non-IDU populations is uncommon, and may reflect the beginning of divergence of HCV genotypes in the IDU population in Prague.

Association of Drowning and Myocarditis in a Pediatric Population: An Autopsy-Based Study

Context.—Drowning is a frequent cause of accidental death in childhood, but the association of myocarditis and drowning has only rarely been reported.

Objective.—To report 5 cases of drowning in children with coexistent myocarditis.

Design.—A retrospective review of autopsy records of patients 0 years to 18 years of age was performed during a 6-year period (1998–2003, total cases reviewed = 1431).

Results.—Twenty-two drownings were identified, in 14 male and 8 female children. Five patients (23%), 3 female and 2 male children, had coexistent myocarditis. The 5 patients ranged in age from 23 months to 13 years (mean, 7 years 2 months). None of the patients had antecedent symptomatology suggestive of myocarditis. In all patients, the myocarditis was focal mild or moderate, and the inflammatory infiltrate comprised lymphocytes with smaller numbers of neutrophils. All 5 patients had foci of myocyte necrosis. One patient had histologic evidence of myocardial hypertrophy but no evidence of a cardiomyopathy. Microbiologic studies, including culture, immunohistochemistry, polymerase chain reaction, and reverse transcriptase polymerase chain reaction, revealed Mycoplasma pneumoniae DNA in 1 case.

Conclusions.—The finding of myocarditis in a significant proportion of drowning victims in this series highlights the importance of a thorough autopsy examination in apparently straightforward cases and has clinicopathologic significance.

Effect of oligonucleotide primers in determining viral variability within hosts

BACKGROUND

Genetic variability in viral populations is usually estimated by means of polymerase chain reaction (PCR) based methods in which the relative abundance of each amplicon is assumed to be proportional to the frequency of the corresponding template in the initial sample. Although bias in template-to-product ratios has been described before, its relevance in describing viral genetic variability at the intrapatient level has not been fully assessed yet.

RESULTS

To investigate the role of oligonucleotide design in estimating viral variability within hosts, genetic diversity in hepatitis C virus (HCV) populations from eight infected patients was characterised by two parallel PCR amplifications performed with two slightly different sets of primers, followed by cloning and sequencing (mean = 89 cloned sequences per patient). Population genetics analyses of viral populations recovered by pairs of amplifications revealed that in seven patients statistically significant differences were detected between populations sampled with different set of primers.

CONCLUSIONS

Genetic variability analyses demonstrates that PCR selection due to the choice of primers, differing in their degeneracy degree at some nucleotide positions, can eclipse totally or partially viral variants, hence yielding significant different estimates of viral variability within a single patient and therefore eventually producing quite different qualitative and quantitative descriptions of viral populations within each host.

Comparison of hepatitis C virus genotyping by 5' noncoding region- and core-based reverse transcriptase PCR assay with sequencing and use of the assay for determining subtype distribution in India

Phylogenetic analysis of the sequences of the 5' noncoding regions (5'NCR) of 149 samples from hepatitis C virus (HCV) RNA-positive chronic carriers representing northern, southern, eastern, and western India showed that type 3 and type 1 are the predominant genotypes circulating in India, with an overall prevalence of 53.69 and 38.25%, respectively. Type 4 viruses (6.04%) were seen only in southern India. Sequence analysis of the core region of 51 of the above isolates enabled us to classify them further into subtypes as 1b (number of isolates [n] = 10), 1a (n = 6), 3a (n = 9), 3g (n = 14), 3f (n = 1), and 4d (n = 3). Three new subtypes were identified for the first time and designated as 3i (n = 5), 3j (n = 2), and 6l (n = 1). Sequencing the 5'NCR could differentiate HCV types, whereas classification at the level of subtype was possible with sequence analysis of the core region.

From RNA to quasispecies: a DNA polymerase with proofreading activity is highly recommended for accurate assessment of viral diversity

RNA viruses are characterized by their high rates of genetic variation. Their genetic diversity is generally studied by reverse transcription (RT) followed by polymerase chain reaction (PCR) amplification and nucleotide (nt) sequence determination. The misinterpretation of viral diversity due to copy errors introduced by the enzymes used in this two-step protocol has not yet been assessed systematically. In order to investigate the impact of such errors, we sought to bypass the intrinsic viral heterogeneity by starting from a homogeneous cDNA template. With this in mind, the hepatitis C virus (HCV) 5' non-coding region (5'NCR) was amplified either by PCR starting from a homopolymeric cDNA template or by RT-PCR starting from the in vitro RNA transcript derived from the same original cDNA template. Amplicons were cloned and the 17-20 individual clones were sequenced in each assay. Different quasispecies patterns were obtained with various commercially available DNA polymerases, resulting in different computed error rates. The non-proofreading Taq DNA polymerase provided the highest error rate which was seven times higher than that obtained with the most reliable of the proofreading polymerases tested. We, therefore, emphasize that the misleading interpretation of the observed heterogeneity for a given viral sample could be due to ignorance of the fidelity of the polymerase used for viral genome amplification, and thus that proofreading DNA polymerases should be preferred for the investigation of natural genetic diversity of RNA viruses.

Risk factors for hepatitis C virus infection among patients receiving health care in a Department of Veterans Affairs hospital

A cross-sectional, seroepidemiological study was conducted to determine the prevalence and risk factors for hepatitis C virus (HCV) infection among veterans receiving health care from the VA. Among 274 evaluated outpatients, anti-HCV was found in 27 (9.9%). The prevalence of anti-HCV was 3.7% among 190 individuals who reported no illicit drug use compared to 24.7% among 81 subjects who had used drugs (P < 0.001). The prevalence of anti-HCV was 4.8% among 208 veterans who had never been incarcerated compared to 27.9% among 61 veterans who had been incarcerated (P < 0.001). A multivariate model found the following factors to be independently associated with anti-HCV; having used illicit drugs [odds ratio (OR) = 3.7, 95% CI 1.3-11.8; P = 0.001), having been incarcerated (OR = 4.4, 95% CI 1.7-10.9; P = 0.001), and a yearly income less than 10,000 US dollars (OR = 3.5, 95% CI 1.3-9.4; P = 0.002). Because HCV infection was most strongly associated with illicit drug use, incarceration, and low income, these risk factors should be utilized to develop screening strategies among VA patients.

Hepatitis C virus subtyping by a core-envelope 1-based reverse transcriptase PCR assay with sequencing and its use in determining subtype distribution among Danish patients

A reverse transcriptase PCR (RT-PCR) assay using conserved primers deduced from the core-envelope 1 (C-E1) region of the hepatitis C virus (HCV) genome was developed for subtyping purposes. The sensitivity and specificity of this assay tested against two HCV reference panels containing genotype 1 through 5 subtypes were similar to those of an RT-PCR assay from the 5'-untranslated region (5'-UTR). The sensitivity of the RT-PCR typing assay in the more variable C-E1 region was, however, lower than that of the RT-PCR in the highly conserved 5'-UTR when testing multiple clinical samples. Thus, 71 (88%) of 81 consecutive samples from hospitalized Danish patients positive for HCV antibodies and RNA (5'-UTR) were positive also in the C-E1 RT-PCR assay. Phylogenetic analysis of the E1 sequences obtained by direct sequencing of HCV from two reference panels and 71 Danish patients allowed us to readily distinguish the subtypes. In contrast, phylogenetic analysis of their corresponding 5'-UTR sequences was able to predict only major genotypes. Three different genotypes and four subtypes were identified among Danish samples: 1a (43%), 1b (11%), 2b (6%), and 3a (39%). An isolate from a Somalian refugee was identified as a new HCV type related to Somalian isolates described as subtype 3h. The most common genotype in Denmark is genotype 1 (53%), which is the most difficult to treat. However, Denmark had the highest prevalence in Europe of subtype 3a, which responds more favorably to treatment. The described C-E1 RT-PCR with sequencing is suggested as an easy routine assay for definitive genotyping and subtyping of HCV.