Hepatitis C virus genotype 6: Virology, epidemiology, genetic variation and clinical implication

Comparison of diagnostic performance among Abbott RealTime HCV Genotyping II, Abbott HCV Genotype plus RUO, and Roche Cobas HCV Genotyping assays for hepatitis C virus genotyping

Comparison of diagnostic accuracy for commercial hepatitis C virus (HCV) genotyping (Abbott RealTime HCV Genotyping II, Roche Cobas Genotyping) and investigational Abbott HCV Genotype plus RUO assays designed to discriminate genotype (GT)-1a, 1b or 6 in cases of ambiguous GT from the Abbott commercial assay remains limited. 743 HCV-viremic samples were subjected to analysis using Abbott and Roche commercial as well as Abbott HCV Genotype plus RUO assays. Next-generation sequencing (NGS) targeting core region was employed as the reference standard. Diagnostic accuracy was reported as the number of participants (percentages) along with 95% confidence intervals (CIs). Using NGS, 741 samples (99.7%) yielded valid genotyping results. The diagnostic accuracies were 97.6% (95% CI: 96.1%-98.5%) and 95.3% (95% CI: 93.4%-96.6%) using Abbott and Roche commercial assays (p = 0.0174). Abbott commercial assay accurately diagnosed HCV GT-6a and 6w, whereas Roche commercial assay accurately diagnosed HCV GT-6a. Both assays demonstrated low accuracies for HCV GT-6b, 6e, 6g, and 6n. Abbott HCV Genotype plus RUO assay discriminated 13 of the 14 samples (92.9%; 95% CI: 64.2%-99.6%) that yielded ambiguous GT. Both assays were capable of diagnosing mixed HCV infections when the minor genotype comprised >8.4% of the viral load. The diagnostic performance of commercial HCV genotyping assays is commendable. Abbott assay demonstrated superior performance compared to Roche assay in diagnosing HCV GT-6. Abbott HCV Genotype plus RUO assay aids in discriminating ambiguous GT. Both commercial assays are proficient in diagnosing mixed HCV infections at a cut-off viral load of 8.4% in minor genotype.

Patients with Hepatitis C Undergoing Direct-Acting Antiviral Treatment Have a Lower SARS-CoV-2 Infection Rate

This study retrospectively analyzed the medical records of 602 patients with first-time positive results for the HCV nucleic acid test between 1 May 2021 and 31 March 2023, exploring the association between DAA treatment and SARS-CoV-2 infection. The results showed that 9.8% of HCV patients were co-infected with SARS-CoV-2. Gender, age, vaccination status, and HCV genotype did not significantly affect SARS-CoV-2 infection. However, patients undergoing DAA treatment showed significantly lower rates of SARS-CoV-2 infection and mortality compared to those not undergoing DAA treatment. The analysis also compared patients undergoing different DAA treatments, with Epclusa and Maviret showing superior protection against SARS-CoV-2. Furthermore, this study explored the severity and mortality of SARS-CoV-2 infection in patients undergoing and having completed DAA treatment. It revealed that patients diagnosed with COVID-19 during DAA treatment experienced only mild symptoms, and none died, suggesting a potential protective effect of DAA treatment against severe outcomes of SARS-CoV-2 infection. The findings contribute to the understanding of the interplay between HCV, DAA treatment, and SARS-CoV-2 infection, highlighting the need for continued monitoring and healthcare measures for individuals with chronic conditions during the ongoing COVID-19 pandemic.

Real-world treatment outcome of direct-acting antivirals and patient survival rates in chronic hepatitis C virus infection in Eritrea

Reliable real-world data on direct acting anti-retroviral (DAA) uptake and treatment outcomes are lacking for patients with hepatitis C virus (HCV) in sub-Saharan Africa. This study provides data on HCV DAA-based treatment outcomes, mortality, loss-to-follow up, and associated factors among patients in Eritrea. A multicenter retrospective observational cohort study was conducted in two tertiary hospitals in Asmara, Eritrea. A structured checklist was used to collect data from patient's cards. Descriptive and inferential statistics used included means (± Standard deviation (SD), medians (Interquartile range (IQR), chi-squire (χ2), Kaplan-Meier estimates, and multivariate Cox proportional hazard models. A total of 238 patients with median age of 59 years (IQR 50-69 years) were enrolled in the study. Out of the 227 patients initiated on treatment, 125 patients had viral load measurements at 12 weeks after end of treatment (EOT) whereas 102 patients had no viral load measurements at 12 weeks EOT. Among the patients with HCV RNA data post-EOT 12, 116 (92.8%) had sustained viral response (SVR). The prevalence of death and loss-to-follow up (LTFU) were (7.5%, 95% CI 1.7-4.1) and 67 (28.1%, 95% CI 22.3-33.9) translating into an incidence of 1.1 (95% CI 0.8-1.5) per 10,000 person days. Independent predictors of LTFU included the enrollment year (2020: aHR = 2.2, 95% CI 1-4.7; p value = 0.04); Hospital (Hospital B: aHR = 2.2, 95% CI 1-4.7; p value = 0.03) and the FIB-4 score (FIB-Score < 1.45: aHR = 3.7, 95% CI 1.2-11.5; p value = 0.02). The SVR rates achieved in this cohort were high. However, high LTFU and high mortality driven largely by late presentation and suboptimal population screening/case finding, were uncovered. These challenges can be addressed by test-and-treat programs that simultaneously prioritize programmatic screening, decentralization of care, and better patient tracking in the HCV care cascade.

Genetic history of hepatitis C virus genotype 6 in Taiwan

Unlike hepatitis C virus (HCV) genotype (GT) 6, which is widely circulated in Southeast Asia and South China, GT 6 was not reported in Taiwan until 2006. GT 1b and 2a, also known as global HCV subtypes, have been reported as major GTs circulating in Taiwan. Because of improvement in genotyping kits and sequencing techniques for the subtyping of HCV, an increasing number of GT 6 subtypes have been reported, especially subtype 6a among intravenous drug users with human immunodeficiency virus infection after an outbreak since 2003. Thus, HCV GT 6 infection is regarded to be closely associated with injection drug use. However, recently, we found an unexpectedly high GT 6 prevalence in the general population in Tainan, southern Taiwan. Most of these GT 6 samples belonged to a putative novel subtype closely related to 6g and 6w instead of 6a. Phylogenetic analyses indicated that this putative 6g-related novel subtype and 6w could be indigenous in southern Taiwan for centuries. Southern Taiwan could be the origin of HCV subtype 6w. This finding might change the perspective of HCV epidemiology in Taiwan.

An Insight into Hepatitis C Virus: In Search of Promising Drug Targets

Hepatitis C Virus (HCV) is a global health concern, chronically infecting over 70 million people worldwide. HCV is a bloodborne pathogen that primarily affects the liver, and chronic HCV infection can lead to cirrhosis, liver cancer, and liver failure over time. There is an urgent need for more effective approaches to prevent and treat HCV. This review summarizes current knowledge on the virology, transmission, diagnosis, and management of HCV infection. It also provides an in-depth analysis of HCV proteins as promising targets for antiviral drug and vaccine development. Specific HCV proteins discussed as potential drug targets include the NS5B polymerase, NS3/4A protease, entry receptors like CD81, and core proteins. The implications of HCV proteins as diagnostic and prognostic biomarkers are also explored. Current direct-acting antiviral therapies are effective but have cost, genotype specificity, and resistance limitations. This review aims to synthesize essential information on HCV biology and pathogenesis to inform future research on improved preventive, diagnostic, and therapeutic strategies against this global infectious disease threat.

Sexually-transmitted hepatitis C virus reinfections among people living with HIV in Taiwan: the emerging role of genotype 6

Hepatitis C virus (HCV) reinfections after successful treatment with direct-acting antivirals (DAAs) pose a significant challenge to HCV elimination, especially among high-risk people living with HIV (PLWH). In this study, PLWH who had achieved HCV viral clearance with DAAs were included between January 2018 and June 2021. PLWH having acquired HCV infections after 2017 were classified as "recent-infection group," and those before 2017 as "remote-infection group," and the incidences of HCV reinfection were compared between two groups. Clinical and behavioural characteristics were evaluated to identify associated factors with HCV reinfection. A total of 284 PLWH were included: 179 in the recent-infection group and 105 in the remote-infection group. After a median follow-up of 2.32 years (interquartile range [IQR], 0.13-3.94), the overall incidence of HCV reinfection was 5.8 per 100 person-years of follow-up (PYFU). The incidence in the recent-infection group was significantly higher than that in the remote-infection group (9.8 vs. 0.4 per 100 PYFU, p < 0.001). The leading HCV genotypes before DAA treatment were genotypes 2 (31.0%), 1b (26.8%), and 6 (21.8%); however, genotype 6 (58.8%) became predominant upon reinfection. Younger age (adjusted odds ratio [aOR] per 1-year increase, 0.95; 95% CI, 0.90-0.99), condomless receptive anal sex (aOR, 14.5; 95% CI, 2.37-88.8), rimming (aOR, 3.87; 95% CI, 1.14-13.1), and recent syphilis (aOR, 2.73; 95% CI, 1.26-5.91) were linked to HCV reinfections. In conclusion, PLWH acquiring HCV after 2017 had a significantly higher risk for sexually-transmitted HCV reinfections. The predominance of HCV genotype 6 reinfections suggests possible on-going clustered HCV infections among at-risk PLWH.

Treatment Response and Drug Resistance Profiling of Genotype 6 of Hepatitis C Virus in HCV/HIV Co-Infected Patients: A Pilot Study from INDIA

Hepatitis C Virus (HCV) genotype (GT) 6 demonstrates maximum genomic diversity out of all the known genotypes of HCV, attributable to its inherent intra-genotype and inter-genotype recombination property. This is the most common genotype seen in HCV/HIV co-infected cases. HIV/HCV co-infection is linked with increased genetic diversity in HCV structural genes. The detailed information on the distribution of HCV GT6, its subtypes, and resistance to currently available antiviral drugs is limited in the Indian subcontinent. Therefore, in this single-center retrospective cross-sectional study, we aimed to map the occurrence of HCV GT6, its subtypes and resistance-associated substitution (RAS), and its correlation with antiviral treatment response in HCV-infected patients. From a cohort of 2052 HCV-infected patients, the overall prevalence of GT6 was 2.5% (n = 53), with a maximum of 81.1% (n = 43) seen in HCV/HIV co-infected patients. Nine different subtypes, 6a, 6b, 6f, 6i, 6n, 6u, 6v, 6w, and 6xa, were detected in the Indian population for the first time, with a predominance of 6xa (41.5%), a rare subtype, followed by 6n (39.6%). The phylogenetic analysis by the neighbor-joining method revealed three prominent viral clades, 6v, 6n, and 6xa–6u. The baseline (before treatment initiation) plasma samples of all GT6-infected patients were retrieved from −80 °C and a part of the NS5a and NS5b region of the viral genome was analyzed for the presence of RAS. No RASs were seen in the NS5b region, while in two patients (3.7%) RASs were seen at baseline in the NS5a region of the virus. Sustained viral response (SVR) was attained in 81% (n = 43) of patients. No difference in GT6 subtype distribution or occurrence of RAS was seen between mono-infected HCV and HIV/HCV co-infected cases. Our study revealed that RAS at baseline did not influence the attainment of SVR and the currently available antiviral therapy is effective against GT6 mono-infected and HIV/HCV co-infected patients.

The Evolutionary Dynamics and Epidemiological History of Hepatitis C Virus Genotype 6, Including Unique Strains from the Li Community of Hainan Island, China

Hepatitis C virus (HCV) is a highly diverse pathogen that frequently establishes a chronic long-term infection, but the origins and drivers of HCV diversity in the human population remain unclear. Previously unidentified strains of HCV genotype 6 (gt6) were recently discovered in chronically infected individuals of the Li ethnic group living in Baisha County, Hainan Island, China. The Li community, who were early settlers on Hainan Island, have a distinct host genetic background and cultural identity compared to other ethnic groups on the island and mainland China. In this report, we generated 33 whole virus genome sequences to conduct a comprehensive molecular epidemiological analysis of these novel gt6 strains in the context of gt6 isolates present in Southeast Asia. With the exception of one gt6a isolate, the Li gt6 sequences formed 3 novel clades from two lineages which constituted 3 newly assigned gt6 subtypes and 30 unassigned strains. Using Bayesian inference methods, we dated the most recent common ancestor for all available gt6 whole virus genome sequences to approximately 2767 BCE (95% HPD intervals, 3670 to 1397 BCE), which is far earlier than previous estimates. The substitution rate was 1.20 x 10-4 substitutions/site/year (s/s/y) and this rate varied across the genome regions, from 1.02 x 10-5 s/s/y in the 5ʹUTR region to 3.07 x 10-4 s/s/y in E2. Thus, our study on an isolated ethnic minority group within a small geographical area of Hainan Island has substantially increased the known diversity of HCV gt6, already acknowledged as the most diverse HCV genotype. The extant HCV gt6 sequences from this study were probably transmitted to the Li through at least three independent events dating perhaps from around 4000 years ago. This analysis describes deeper insight into basic aspects of HCV gt6 molecular evolution including the extensive diversity of gt6 sequences in the isolated Li ethnic group.

Complete genome sequencing and evolutionary analysis of hepatitis C virus subtype 6a, including strains from Guangdong Province, China

We performed an evolutionary analysis using whole genome sequence isolates of hepatitis C virus (HCV) 6a from Guangdong Province and reference sequences from various countries. Less than 5% of the HCV genome was found to be under positive selection. The E1 and E2 proteins had the highest proportion of positively selected sites both within and outside of CD8 T cell epitopes in all of the strains. Regions corresponding to CD8 T cell epitopes were under negative selection except in the isolates from Guangdong. Furthermore, we found evidence of three introductions of the virus into Guangdong from Vietnam and other Southeast Asian countries. Thus, this study provides information about the transmission of HCV 6a by comparison of full-length sequences, indicating the impact of selective constraints in Guangdong and across China.

Hepatitis C Virus Subtypes Novel 6g-Related Subtype and 6w Could Be Indigenous in Southern Taiwan with Characteristic Geographic Distribution

Hepatitis C virus (HCV) genotype (GT) 6 is the most genetically diverse GT and mainly distributed in Southeast Asia and south China but not Taiwan. Earlier studies showed the major HCV GTs in Taiwan were GT 1b and 2 with very rare GT 6 except in injection drug users (IDUs), and subtype 6a is the main GT 6 subtype among IDUs. Recently, we reported a much higher prevalence (18.3%) of GT 6 in Tainan City, southern Taiwan. This study was designed to clarify the subtypes of GT 6 in this endemic area. A total of 3022 (1343 men and 1679 women) HCV viremic patients were enrolled. Subtypes of GT 6 were determined by sequencing of core/E1 and nonstructural protein 5B in 322 of 518 GT 6 patients. The overall GT 6 prevalence rate was 17.1% (518/3022), with higher prevalence districts (>25%) located in northern Tainan. A novel 6g-related subtype is the most prevalent subtype (81.0%), followed by 6w (10.8%), 6a (7.5%), and 6n (0.7%). The high GT 6 prevalence in Tainan was mainly due to a novel 6g-related subtype and 6w. These two subtypes could be indigenous in Tainan with characteristic geographic distribution.

Effects of infections on the pathogenesis of cancer

Several studies have shown an inverse relationship between acute infections and cancer development. On the other hand, there is a growing evidence that chronic infections may contribute significantly to the carcinogenesis. Factors responsible for increased susceptibility to infections may include modifications of normal defence mechanisms or impairment of host immunity due to altered immune function, genetic polymorphisms, ageing and malnourishment. Studies have demonstrated that children exposed to febrile infectious diseases show a subsequent reduced risk for ovarian cancer, melanoma and many other cancers, while common acute infections in adults are associated with reduced risks for melanoma, glioma, meningioma and multiple cancers. Chronic inflammation associated with certain infectious diseases has been suggested as a cause for the development of tumours. Mechanisms of carcinogenesis due to infections include cell proliferation and DNA replication by mitogen-activated protein kinase pathway, production of toxins that affect the cell cycle and lead to abnormal cell growth and inhibition of apoptosis. This review was aimed to summarize the available evidence on acute infections as a means of cancer prevention and on the role of chronic infections in the development and progression of cancer.

The Growing Problem of Hepatitis C Virus Infection: The Case of West Virginia

Hepatitis C virus (HCV) is one of the most significant public health problems currently facing the United States, especially in West Virginia. If it is undetected and left untreated, the likelihood of sustaining a treatment response decreases. While early identification has been identified as a critical focus in trying to obtain better health outcomes, new drug treatments appear promising, if somewhat expensive. West Virginia is a predominantly rural state, where the incidence of HCV is 9 times the national average and Medicaid costs for treatment amounted to more than $27 million from 2014 to 2016. The purpose of this study was to conduct a systematic review of the effects of early identification and treatment for patients infected with HCV as it relates to West Virginia. A comprehensive systematic review was limited to 58 articles published from 2008 to 2018 and were in English. Findings from this review identified early detection as the first line of a preventive strategy to help reduce the evolving epidemic and that oral medications could reduce the risk of liver cancer and death. The cost associated with hospitalization of HCV more than tripled from $20 963 in 2005 to $64 867 in 2011 with the average charge per hospitalization at $53 626 due to HVC. The lack of adequate treatment options has led to increasing (and even more expensive) hospital care for untreated HCV. These facts suggest that this state might be facing an expected financial health care crisis due to its increasingly drug-related HCV-infected population.

Use of glecaprevir/pibrentasvir in patients with chronic hepatitis C virus infection and severe renal impairment

Background/Aims

Data on treatment efficacy and safety of glecaprevir/pibrentasvir (GLE/PIB) for chronic hepatitis C virus (HCV) infection in Asian patients with severe renal impairment are limited. This study aimed to study the treatment and side effects of GLE/PIB in these patients infected with non-1 genotype (GT) HCV.

Methods

We prospectively recruited patients with Child’s A cirrhosis and eGFR <30 mL/min/1.73 m² in Hong Kong and Taiwan during 2017–2018 to receive GLE/PIB treatment.

Results

Twenty-one patients (GT2, n=7; GT3, n=6; and GT6, n=8) received GLE/PIB for 11.2±1.8 weeks. All except one were treatment-naïve. GLE/PIB was initiated in 16 patients while on dialysis (seven on peritoneal dialysis [PD] and nine on hemodialysis) and in five patients before dialysis. One patient died of PD-related peritonitis during treatment and two were lost to follow up. The SVR12 rate in the remaining 18 patients was 100%. All patients achieved undetectable levels at 4-, 12-, 24- and 48-week after treatment. Patients with deranged alanine aminotransferase showed normalization after 4 weeks and the response was sustained for 48 weeks. No significant adverse event was observed.

Conclusions

GLE/PIB treatment was associated with high efficacy and tolerability in HCV-infected patients with severe renal impairment.

Geographic variation of genotype 6 hepatitis C virus infection in an endemic area of southern Taiwan

Taiwan is a hepatitis C virus (HCV) endemic country with geographic variation of prevalence and main genotypes(GTs) are 1 b and 2a. We recently reported high GT6 prevalence in Tainan of southern Taiwan. To clarify this special genotype as a local endemic disease and its geographic variation, the prevalence rates of HCV GTs of 37 districts of Tainan were analyzed. A total of 3040 patients with HCV viremia were enrolled. The prevalence rates of HCV GT 1a, 1 b, 2, 3, 4, 6 and mixed types were 3.9%, 31.6%, 45.9%, 0.6%, 0.2%, 17.1% and 0.5% respectively. GT6 prevalence showed marked variation from 0 to 39.2%. Four districts with GT6 prevalence >30% are located between Jishui and Zengwen rivers. Preliminary subtyping data were 6 g/a/w. This geographic variation with spatial restriction by two rivers with 6 g/w is suggestive of local endemic infection of preexisting GT 6 HCV for centuries.

Genetic diversity of genotype 6 HCV infections in France: Epidemiology and consequences for treatment strategy

Genotype-6 hepatitis C virus (GT6-HCV) exhibits a high genetic diversity. GT6 prevalence, diversity and real-life response to treatment were studied among 14 603 HCV mono-infected patients from the French ANRS-CO22-Hepather cohort. NS3, NS5A and NS5B-HCV genes were amplified and sequenced for all GT6-infections identified in the database. Following phylogenic characterization, resistance-associated substitution polymorphisms were identified. GT6-infected patients (n = 36; 0.25%) did not differ from patients infected with other genotypes with regard to gender, age or liver fibrosis. GT6e was the most prevalent (27.8%), followed by 6a (22.2%), 6q (11.1%) and 6o (8.3%). Each subtype p and xc were found in two patients (5.6%) and subtypes f/h/r and t were each detected in one patient. Four strains (11.1%) clustered with unclassified reference sequences. Concordant genotype determination throughout NS3, NS5A and NS5B-genes is consistent with lack of recombination within this genomic region. All, but three patients were born in Asia, Cambodia (44.4%), Vietnam (38.9%) or Laos (8.3%). GT6a were found in 42.8% of Vietnamese and 6e in 37.5% of Cambodian. GT6q, 6p and 6r were only found in Cambodian patients. Resistance-associated polymorphisms for each DAA classes were identified in baseline sequences. Twenty-seven patients were treated with sofosbuvir-based combinations and 3 with glecaprevir/pibrentasvir. All treated patients, whether naïve or previously treated, achieved a sustained viral response. In conclusion, GT6-infections are uncommon in France and their genetic diversity likely reflects infection within the country of origin. Despite residue variability at DAA resistance-associated positions, sustained viral response was obtained in all treated patients.

High prevalence of genotype 6 hepatitis C virus infection in Southern Taiwan using Abbott genotype assays

BACKGROUND/PURPOSE

Abbott RealTime Genotype II assay can effectively identify hepatitis C virus (HCV) genotypes (GTs), but some GT 6 subtypes might not be differentiated from GT 1. Abbott RealTime Genotype II PLUS and sequencing might be needed to resolve these ambiguous results. Unlike the high prevalence of GT 6 in Southeast Asia, GT 6 had rarely been reported in Taiwan except in intravenous drug abusers (IDU). But the prevalence of GT 6 in Taiwan might be underestimated. We conducted this study to determine the GTs in a HCV endemic area in Southern Taiwan.

METHODS

A total of 1147 patients with hepatitis C viremia for direct acting antivirals (DAA) treatment at the Chi Mei medical system in Tainan were enrolled. Genotype was determined using a working flow consisted of Abbott GT II, PLUS assays and 5' untranslated region (5' UTR)/core sequencing.

RESULTS

Among the 1147 patients, 883 (77.0%) obtained GT results by GT II, 264 (23.0%) samples with ambiguous results by GT II assay received further tests, including 194 (73.5%) with PLUS assay and 70 (26.5%) with 5'UTR/core sequencing. Nearly three-quarters (73.5%) of ambiguous results by GT II assay were GT 6. Overall, 18.3% of samples were GT 6. Phylogenetic study of 11 samples of GT 6 subtypes showed 7 (63.6%) were 6 g.

CONCLUSION

GT 6 is the major factor for high ambiguous rate by GT II. Unexpected high prevalence of GT 6 (18.3%) in Southern Taiwan, especially subtype 6 g, closely related to Indonesian strains, is first reported.

Identification of a New HCV Subtype 6xg Among Injection Drug Users in Kachin, Myanmar

Characterizing hepatitis C virus (HCV) genetic diversity not only allows us to trace its origin and evolutionary history, but also provides valuable insights into diagnosis, prevention and therapy of HCV infection. Although eight HCV genotypes and 86 subtypes have been classified, there are still some HCV variants that need to be assigned. The genotype 6 is the most diverse HCV genotype and mainly prevalent in Southeast Asia. In this study, we identified a new HCV subtype 6xg from injection drug users (IDUs) in Kachin, Myanmar. A distinctive feature of 6xg from other subtypes of the genotype 6 was a Lys insertion in NS5A gene, which changes the RRKR/K motif into RRKKR/K. Bayesian analyses showed that HCV 6xg originated during 1984–1988, and experienced a rapid population expansion during 2005–2009. We characterized HCV subtype profile among IDUs in this region, and detected six HCV subtypes, including 1a (12.0%), 3a (12.0%), 3b (24.0%), 6n (16.0%), 6xa (20.0%), and 6xg (12.0%). Importantly, we found that HCV subtype distribution in Kachin was very similar to that in Dehong prefecture of Yunnan, but very distinct from those in other regions of Myanmar and Yunnan, indicating that the China–Myanmar border region shared a unique HCV subtype pattern. The appearance of 6xg and the unique HCV subtype profile among IDUs in the China–Myanmar border region have significant epidemiological and public health implications.

Differential prevalence and geographic distribution of hepatitis C virus genotypes in acute and chronic hepatitis C patients in Vietnam

BACKGROUND

The highest burden of disease from hepatitis C virus (HCV) is found in Southeast Asia, but our understanding of the epidemiology of infection in many heavily burdened countries is still limited. In particular, there is relatively little data on acute HCV infection, the outcome of which can be influenced by both viral and host genetics which differ within the region. We studied HCV genotype and IL28B gene polymorphism in a cohort of acute HCV-infected patients in Southern Vietnam alongside two other cohorts of chronic HCV-infected patients to better understand the epidemiology of HCV infection locally and inform the development of programs for therapy with the increasing availability of directly acting antiviral therapy (DAAs).

METHODS

We analysed plasma samples from patients with acute and chronic HCV infection, including chronic HCV mono-infection and chronic Human Immunodeficiency Virus (HIV)-HCV coinfection, who enrolled in four epidemiological or clinical research studies. HCV infection was confirmed with RNA testing. The 5' UTR, core and NSB5 regions of HCV RNA positive samples were sequenced, and the genotype and subtype of the viral strains were determined. Host DNA from all HCV positive patients and age- and sex-matched non-HCV-infected control individuals were analysed for IL28B single nucleotide polymorphism (SNP) (rs12979860 and rs8099917). Geolocation of the patients were mapped using QGIS.

RESULTS

355 HCV antibody positive patients were analysed; 54.6% (194/355) and 46.4% (161/355) were acute and chronic infections, respectively. 50.4% (81/161) and 49.6.4% (80/161) of chronic infections had HCV mono-infection and HIV-HCV coinfection, respectively. 88.7% (315/355) and 10.1% (36/355) of the patients were from southern and central regions of Vietnam, respectively. 92.4% (328/355) of patients were HCV RNA positive, including 86.1% (167/194) acute and 100% (161/161) chronic infections. Genotype could be determined in 98.4% (322/328) patients. Genotypes 1 (56.5%; 182/322) and 6 (33.9%; 109/322) predominated. Genotype 1 including genotype 1a was significantly higher in HIV-HCV coinfected patients compared to acute HCV patients [43.8% (35/80) versus 20.5% (33/167)], (p = <0.001), while genotype 6 was significantly higher in chronic HCV mono-infected patients [(44.4% (36/81) versus 20.0% (16/80)] (p = < 0.004) compared to HIV-HCV coinfected patients. The prevalence of IL28B SNP (rs12979860) homozygous CC was 86.46% (83/96) in control individuals and was significantly higher in acutely-infected compared to chronically-infected patients [93.2 (82/88) versus 76.1% (35/46)] (p = < 0.005).

CONCLUSION

HCV genotype 6 is highly prevalent in Vietnam and the high prevalence in treatment naïve chronic HCV patients may results from poor spontaneous clearance of acute HCV infection with genotype 6.

Safety and efficacy of sofosbuvir-based direct-acting antiviral regimens for hepatitis C virus genotype 6 in Southwest China: Real-world experience of a retrospective study

Optional treatments for patients with chronic hepatitis C virus (HCV) genotype (GT) 6 infection have not been extensively studied. This study aimed to evaluate the safety and efficacy of sofosbuvir (SOF)-based direct-acting antiviral agents (DAAs) for HCV GT6. We performed a retrospective study at the West China Hospital of Sichuan University in Southwest China from January 2016 to May 2017. Our study screened 130 treatment-naïve patients with chronic HCV GT6 and without liver cirrhosis. A total of 60 HCV GT6 patients were ultimately enrolled. All patients received SOF-based DAAs therapy, including SOF 400 mg plus daclatasvir (DCV) 60 mg daily or SOF 400 mg plus velpatasvir (VEL) 100 mg daily for 12 weeks. The sustained virological response 12 weeks after treatment (SVR12) was 100% (60/60) in treatment-naïve patients with HCV GT6, including 100% (37/37) of patients receiving SOF plus DCV therapy and 100% (23/23) of patients receiving SOF plus VEL therapy. Measurements of liver stiffness were significantly decreased in patients at week 12 (P = 0.014) and week 24 (P < 0.001) of DAAs treatment compared to baseline values. The serum biomarker aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 score were also significantly reduced at week 12 and week 24 compared to before treatment (both P < 0.001). SOF-based therapy was well-tolerated, and no serious adverse events were reported. In conclusion, SOF plus DCV and SOF plus VEL were safe and achieved a high SVR12 rate for treatment-naïve patients with HCV GT6 without liver cirrhosis.

Hepatitis C virus and its genotypes in chronic liver disease patients from Meghalaya, Northeast India

Background and Objectives

Hepatitis C virus (HCV) is an important cause of chronic liver disease (CLD). Although Northeast India is believed to be a HCV hotspot, the proportion of HCV infection and the distribution of HCV genotypes in CLD cases from the region are not known. The objectives of the study were to determine the proportion of HCV infection in newly diagnosed CLD patients from Meghalaya, Northeast India, and further investigate the HCV genotype distribution in those patients.

Materials and Methods

The aetiology of CLD was evaluated in 196 newly diagnosed patients, recruited consecutively over a period of 1 year in a medical college hospital from Meghalaya. Those positive for HCV infection were genotyped, and the mode of transmission of the virus was investigated.

Results

A considerable proportion (43 patients, 21.9%) of CLD patients were positive for HCV (95% confidence interval [CI]: 16.7%-28.2%). Other leading causes of CLD were alcohol (36.32%) and hepatitis B virus infection (39.3%). Genotype 3 was the most prevalent (48.7%, 95% CI: 33.9%-63.8%), followed by genotype 6 (30.8%, 95% CI: 18.6%-46.6%) and genotype 1 (20.5%, 95% CI: 10.8%-35.5%). The frequency of genotype 6 was remarkably higher than in the other regions of India. Injecting drug use appeared to be the most common mode (28 patients) of acquiring HCV. This was true irrespective of the genotype.

Conclusions

The presence of HCV in newly diagnosed CLD cases from Meghalaya was considerable. The genotype distribution of HCV was distinct from the other regions of India.

Efficacy and safety of glecaprevir/pibrentasvir in patients with chronic hepatitis C virus genotype 5 or 6 infection (ENDURANCE-5,6): an open-label, multicentre, phase 3b trial

BACKGROUND

The pangenotypic direct-acting antiviral regimen of glecaprevir coformulated with pibrentasvir is approved to treat chronic hepatitis C virus (HCV) genotype 1-6 infection in adults. In registrational studies, 84 (99%) of 85 patients with HCV genotype 5 or 6 infection achieved a sustained virological response (SVR) with glecaprevir/pibrentasvir, with no virological failures. To increase the body of data for these less prevalent genotypes, ENDURANCE-5,6 evaluated the efficacy and safety of glecaprevir/pibrentasvir exclusively in patients infected with HCV genotype 5 or 6.

METHODS

ENDURANCE-5,6 was a phase 3b, single-arm, open-label, multicentre trial done in 24 hospitals or clinics in Europe, Oceania, North America, South Africa, and southeast Asia. Adults with chronic HCV genotype 5 or 6 infection who were previously untreated or treatment-experienced were eligible to be enrolled. Glecaprevir/pibrentasvir (300 mg/120 mg) was given orally once daily for 8 weeks (for patients without cirrhosis) or 12 weeks (for patients with compensated cirrhosis). The primary efficacy endpoint was SVR12 (ie, HCV RNA <15 IU/mL at 12 weeks post-treatment), assessed within each HCV genotype, and analysed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT02966795.

FINDINGS

Between Feb 9, 2017, and Aug 28, 2018, 84 patients were enrolled: 23 with genotype 5 infection and 61 with genotype 6 infection. Overall, 82 (97·6%, 95% CI 94·4-100·0) of the 84 patients achieved SVR12. 22 (95·7%, 95% CI 87·3-100·0) of 23 patients with genotype 5 infection achieved SVR12, as did 60 (98·4%, CI 95·2-100·0) of 61 with genotype 6 infection. One patient with an HCV genotype 6f infection and cirrhosis had on-treatment virological failure at treatment week 12, and one patient with HCV genotype 5a without cirrhosis who had achieved SVR at post-treatment week 4 relapsed at post-treatment week 12. Five (6%) patients had serious adverse events, none of which were deemed related to glecaprevir/pibrentsavir or led to discontinuation. Fatigue (11 [13%] patients) and headache (11 [13%]) were the only adverse events that occurred in 10% or more of patients. No post-baseline grade 3 or higher increases in aminotransferase concentrations were reported.

INTERPRETATION

Glecaprevir/pibrentasvir achieved high SVR12 rates, comparable with data reported in registrational studies, and was well tolerated in patients with HCV genotype 5 or 6 infection with compensated liver disease.

FUNDING

AbbVie.

Evaluation of cost-effectiveness of peginterferon plus ribavirin for chronic hepatitis C treatment and direct-acting antiviral agents among HIV-infected patients in the prison and community settings

BACKGROUND

In Taiwan, the majority of chronic hepatitis C carriers with HIV co-infection are intravenous drug users and inmates in correctional facilities. Peginterferon and ribavirin (PegIFN/RBV) have been the standard-of-care for chronic hepatitis C virus (HCV) infection more than decades. We evaluated the estimated cost-effectiveness of PegIFN/RBV from the National Health Insurance Research Database, covering the population of Taiwan from 1998 to 2013.

MATERIALS AND METHODS

This is an observational study, and study during was 2010-2016 and a total of 239 patients were treated with PegIFN/RBV. Of them, 156 patients were treated in the correctional facilities of Taipei, Taoyuan, Taichung and Taitung prisons, and 83 patients were treated in communities. The cost-effectiveness was analyzed in regimens of PegIFN/RBV and direct-acting antiviral agents.

RESULTS

By multivariate analysis, the patients completed PegIFN/RBV in prison (adjusted odds ratio [aOR]: 4.56, 95% confidence interval [CI]: 1.58-13.12, p = 0.005), HCV RNA level <800,000 IU/mL (aOR: 4.0, 95% CI: 1.27-12.66, p = 0.02) at baseline, and the presence of early virologic response (EVR) (aOR: 7.67, 95% CI: 1.89-31.06, p = 0.004) were independent predictors for sustained virologic response (SVR). For the subgroups of prisoners, HIV-infected prisoners and HIV-infected patients in communities, the SVR rate was 73.8%, 72.0% and 36.8%, and the average medical-care cost was US$7,701, $7,893, and $15,443 per SVR achieved, respectively. Also, the estimated medical-care cost for genotype 6 was US$9211.

CONCLUSIONS

Chronic HCV/HIV co-infected patients with genotype 1 and 6 in the community setting could benefit from DAAs in Taiwan.

Hepatitis C virus genetic diversity by geographic region within genotype 1-6 subtypes among patients treated with glecaprevir and pibrentasvir

Hepatitis C virus (HCV) is genetically diverse and includes 7 genotypes and 67 confirmed subtypes, and the global distribution of each HCV genotype (GT) varies by geographic region. In this report, we utilized a large dataset of NS3/4A and NS5A sequences isolated from 2348 HCV GT1-6-infected patients treated with the regimen containing glecaprevir/pibrentasvir (GLE/PIB) to assess genetic diversity within HCV subtypes by geographic region using phylogenetic analyses, and evaluated the prevalence of baseline amino acid polymorphisms in NS3 and NS5A by region/country and phylogenetic cluster. Among 2348 NS3/4A and NS5A sequences, phylogenetic analysis identified 6 genotypes and 44 subtypes, including 3 GT1, 8 GT2, 3 GT3, 13 GT4, 1 GT5, and 16 GT6 subtypes. Phylogenetic analysis of HCV subtype 1a confirmed the presence of two clades, which differed by geographic region distribution and NS3 Q80K prevalence. We detected phylogenetic clustering by country in HCV subtypes 1a, 1b, 2a, 2b, and 5a, suggesting that genetically distinct virus lineages are circulating in different countries. In addition, two clades were detected in HCV GT4a and GT6e, and NS5A amino acid polymorphisms were differentially distributed between the 2 clades in each subtype. The prevalence of NS3 and NS5A baseline polymorphisms varied substantially by genotype and subtype; therefore, we also determined the activity of GLE or PIB against replicons containing NS3/4A or NS5A from HCV GT1-6 clinical samples representing 6 genotypes and 21 subtypes overall. GLE and PIB retained activity against the majority of HCV replicons containing NS3/4A or NS5A from HCV GT1-6 clinical samples, with a median EC50 of 0.29 nM for GLE and 1.1 pM for PIB in a transient replicon assay. The data presented in this report expands the available data on HCV epidemiology, subtype diversity by geographic region, and NS3 and NS5A baseline polymorphism prevalence.

Eliminating hepatitis C within low-income countries - The need to cure genotypes 4, 5, 6

Around 70 to 100 million people are chronically infected with HCV worldwide. HCV antiviral drug development has revolutionised the treatment of HCV, with several direct-acting antiviral agents offering patients the chance of cure after only 8-12 weeks of treatment. Drug development was initially focussed on HCV genotype 1 (GT1) infection, since this was the most prevalent worldwide, although clinical trials included all genotypes prevalent in the US and Europe. Because the earliest in vitro assays utilised the GT1b and 2 replicons, the initial classes of direct-acting antivirals (protease inhibitors, non-nucleotide polymerase inhibitors) were GT1-specific, albeit they had an effect on other less prevalent genotypes. Epidemiological data has shown the regional importance of other HCV genotypes. More than 50% of all HCV infections around the globe are not with GT1. The prevalence of HCV genotype 4 (GT4), 5 (GT5), and 6 (GT6) is increasing in North America and Europe due to migration from the Middle East, Africa and South-East Asia. With the successful development of the multi and pan-genotypic non-structural protein 5A inhibitors, second generation protease inhibitors and nucleotide non-structural protein 5B inhibitors comes a unique opportunity to achieve global HCV elimination. The goal of this review is to summarise the available information pertaining to GT4, GT5 and GT6, with a specific focus on direct-acting antiviral agents.

Genotype distribution and treatment response among incarcerated drug-dependent patients with chronic hepatitis C infection

The prevalence of hepatitis C virus (HCV) infection is disproportionately high among prisoners, especially among those who are drug-dependent. However, current screening and treatment recommendations are inconsistent for this population, and appropriate care is not reliably provided. To address these problems, the present study aimed to identify unique characteristics and clinical manifestations of incarcerated patients with HCV infection. We included incarcerated patients who received treatment with pegylated-interferon combined with ribavirin at Mackay Memorial Hospital in Taitung and were serving sentences at either the Taiyuan Skill Training Institute or the Yanwan Training Institute. HCV genotypes 1 (41.4%), 3 (25.9%), and 6 (24.1%) were the most prevalent in the incarcerated patients. During the study period, we analyzed treatment response among 58 incarcerated patients and compared obtained results with treatment response among 52 patients who were living in the community. Higher sustained virological response rate was observed among patients with incarceration and HCV genotype other than 1. The odds ratios (corresponding 95% confidence intervals) for incarceration and genotype 1 were 2.75 (1.06–7.11) and 0.37 (0.14–0.99), respectively. Better treatment compliance among incarcerated patients might partially explain these results. The results of this study suggest that treatment of prisoners with HCV infection is feasible and effective. More appropriate and timely methods are needed to prevent HCV transmission among injection drug users inside prisons.

Clinical Characteristics and Treatment Outcome of Peginterferon Plus Ribavirin in Patients Infected with Genotype 6 Hepatitis C Virus in Korea: A Multicenter Study

Background/Aims

Because of the limited geographic distribution, there have been insufficient data regarding hepatitis C virus (HCV) genotype 6 in Korea. This study aimed to investigate the clinical characteristics and available treatment outcomes of patients with genotype 6 HCV in Korea.

Methods

From 2004 to 2014, data were collected from Korean patients infected with genotype 6 HCV in eight hospitals.

Results

Thirty-two patients had genotype 6 HCV. The median age was 44 years, and 6c was the most common subtype. The baseline median alanine transaminase level was 88 (21 to 1,019) IU/mL, and the HCV RNA level was 1,405,000 (96,500 to 28,844,529) IU/mL. Twenty-five patients were treated with peginterferon (PEG-IFN) and ribavirin. Three follow-up losses occurred. Additionally, 13 patients attained a sustained virologic response (SVR), seven patients relapsed, and two patients exhibited a null response. The SVR rates were 40% and 75% for the 24- and more than 48-week treatments, respectively, and five of the six patients who achieved a rapid virologic response (RVR) attained a SVR.

Conclusions

Korean patients infected with genotype 6 HCV are relatively young, and 6c is the most common subtype. When treated with PEG-IFN and ribavirin, the SVR rate was 52%. Similar to other genotypes, a longer duration of treatment and attainment of RVR are important for SVR.

Towards pathogen inactivation of red blood cells and whole blood targeting viral DNA/RNA: design, technologies, and future prospects for developing countries

Over 110 million units of blood are collected yearly. The need for blood products is greater in developing countries, but so is the risk of contracting a transfusion-transmitted infection. Without efficient donor screening/viral testing and validated pathogen inactivation technology, the risk of transfusion-transmitted infections correlates with the infection rate of the donor population. The World Health Organization has published guidelines on good manufacturing practices in an effort to ensure a strong global standard of transfusion and blood product safety. Sub-Saharan Africa is a high-risk region for malaria, human immunodeficiency virus (HIV), hepatitis B virus and syphilis. Southeast Asia experiences high rates of hepatitis C virus. Areas with a tropical climate have an increased risk of Zika virus, Dengue virus, West Nile virus and Chikungunya, and impoverished countries face economical limitations which hinder efforts to acquire the most modern pathogen inactivation technology. These systems include Mirasol® Pathogen Reduction Technology, INTERCEPT®, and THERAFLEX®. Their procedures use a chemical and ultraviolet or visible light for pathogen inactivation and significantly decrease the threat of pathogen transmission in plasma and platelets. They are licensed for use in Europe and are used in several other countries. The current interest in the blood industry is the development of pathogen inactivation technologies that can treat whole blood (WB) and red blood cell (RBC). The Mirasol system has recently undergone phase III clinical trials for treating WB in Ghana and has demonstrated some efficacy toward malaria inactivation and low risk of adverse effects. A 2nd-generation of the INTERCEPT® S-303 system for WB is currently undergoing a phase III clinical trial. Both methodologies are applicable for WB and components derived from virally reduced WB or RBC.

Molecular epidemiology of hepatitis C infections in Ningxia, China: genotype, phylogeny and mutation analysis

Background

Current prevalence and genotype distribution of hepatitis C virus (HCV) infection remain unknown in Ningxia, northwest China.

Methods

From June to December 2013, 13,022 individuals were screened in Ningxia HIV/AIDS Sentinel Surveillance System, with their demographic features collected and serum samples tested for HCV antibody. Sero-positive drug users were further subjected to sequencing of NS5B and Core regions of HCV.

Results

The anti-HCV prevalence was 0.34 % among individuals without history of drug use, while it was 15.80 % among drug users. Of 79 NS5B sequences amplified from drug users, 64 (81.0 %) were male and 51 (64.0 %) were injection drug users (IDUs). Subtype 3a (40.5 %) and 1b (25.3 %) were the most predominant subtypes, followed in frequency by 3b (10.1 %) and 2a (7.6 %). Subtype distribution has no significant difference between injection and non-injection drug users. Based on phylogeographic analysis, HCV strains in Ningxia IDUs were mainly originated from two sites, Yunnan province (in southwest China bordering Myanmar, also known as Burma) and Xinjiang Autonomous Region (in northwest China on the border of Central Asia), which are the two major drug trafficking originates in China. Previously reported drug-resistance mutations were also scanned in this treatment-naïve population. Amino acid substitutions (C316N) associated with direct anti-viral agents (DAA) resistance were identified in the NS5B region in seven samples.

Conclusion

This study is the first to reveal the existence of multiple genotypes of HCV in Ningxia, an inland province in northwest China, suggesting the rapid spreading of the virus.

Electronic supplementary material

The online version of this article (doi:10.1186/s12985-016-0635-y) contains supplementary material, which is available to authorized users.

HCV Diversity among Chinese and Burmese IDUs in Dehong, Yunnan, China

HCV transmission is closely associated with drug-trafficking routes in China. Dehong, a prefecture of Yunnan, is the important trade transfer station linking Southeast Asia and China, as well as the drug-trafficking channel linking “Golden triangle” and other regions of China and surrounding countries. In this study, we investigated the HCV genotype diversity among IDUs in Dehong based on 259 HCV positive samples from 118 Chinese and 141 Burmese IDUs. HCV genotypes were determined based on the phylogenies of C/E2 and NS5B genomic sequences. Six HCV subtypes, including 1a, 1b, 3a, 3b, 6n and 6u, were detected. Interestingly, 4 HCV sequences from Burmese IDUs did not cluster with any known HCV subtypes, but formed a well-supported independent clade in the phylogenetic trees of both C/E2 and NS5B, suggesting a potential new HCV subtype circulating in Dehong. Subtype 3b was the predominant subtype, followed by subtypes 6n and 6u. Comparison showed that Dehong had a unique pattern of HCV subtype distribution, obviously different from other regions of China. In particular, HCV subtypes 6u and the potential new HCV subtype had a relatively high prevalence in Dehong, but were rarely detected in other regions of China. There was no significant difference in HCV subtype distribution between Burmese and Chinese IDUs. Few HCV sequences from Burmese and Chinese IDUs clustered together to form transmission clusters. Furthermore, about half of HCV sequences from Burmese IDUs formed small transmission clusters, significantly higher than that from Chinese IDUs (p<0.01). These suggest that the Chinese and Burmese IDUs were relatively isolated from each other in injection drug use behavior and the Burmese IDUs might prefer to inject drugs themselves together. The unique genotype distribution and complex diversity of genotype 6 among IDUs may be associated with the special geographical position of Dehong.

The burden of cirrhosis and impact of universal coverage public health care system in Thailand: Nationwide study

BACKGROUND AND RATIONALE

Cirrhosis is responsible for significant health-care costs and morbidity. This study aims to evaluate the burden of illness associated with cirrhosis, its impact on the universal coverage public health care system in Thailand.

MATERIAL AND METHODS

We used data from the 2010 Nationwide Hospital Admission Data, the National Health Security Office (NHSO), Thailand. Their baseline characteristics, hospital costs, and outcomes were analyzed according to national health insurance categories including medical welfare scheme (MWFS), social security scheme (SSS) and civil servant medical benefit scheme (CSMBS).

RESULTS

92,301 admissions were eligible for analysis. The mean age was 55 ± 12.8 years, and 63.3% of patients were above 50 years old. The majority of patients (79%) belonged to the MWFS group. The MWFS group incurred the lowest medical expense and had the shortest hospital stay compared to the SSS and CSMBS groups. Overall in-hospital mortality was 10.7%. Cirrhosis complications include bleeding esophageal varices, spontaneous bacterial peritonitis, hepatic encephalopathy, hepatorenal syndrome, and hepatocellular carcinoma. These complications significantly increased mortality rates compared to patients without complications (26 vs. 8.9%, p < 0.001). In-hospital mortality of patients with cirrhosis complications did not differ among the three national health insurance groups. Respiratory failure and septicemia were associated with the highest risk of death (HR 5.4; 95% CI: 4.8-5.9 and HR 5.2; 95% CI: 4.9-5.6 respectively; P < 0.001).

CONCLUSIONS

Illness associated with cirrhosis is a significant public health problem in Thailand. Outcomes of cirrhosis complications did not differ between universal public health care coverage systems in Thailand.

Reducing Hepatocyte Injury and Necrosis in Response to Paracetamol Using Noncoding RNAs

The liver performs multiple functions within the human body. It is composed of numerous cell types, which play important roles in organ physiology. Our study centers on the major metabolic cell type of the liver, the hepatocyte, and its susceptibility to damage during drug overdose. In these studies, hepatocytes were generated from a renewable and genetically defined resource. In vitro-derived hepatocytes were extensively profiled and exposed to varying levels of paracetamol and plasma isolated from liver-failure patients, with a view to identifying noncoding microRNAs that could reduce drug- or serum-induced hepatotoxicity. We identified a novel anti-microRNA, which reduced paracetamol-induced hepatotoxicity and glutathione depletion. Additionally, we identified a prosurvival role for anti-microRNA-324 following exposure to plasma collected from liver failure patients. We believe that these studies represent an important advance for the field, demonstrating the power of stem cell-derived systems to model human biology "in a dish" and identify novel noncoding microRNAs, which could be translated to the clinic in the future.

SIGNIFICANCE

The liver performs vital functions within the human body and is composed of numerous cell types. The major metabolic cell type of the liver, the hepatocyte, is susceptible to damage during drug overdose. In these studies, hepatocytes were generated from a renewable resource and exposed to varying levels of paracetamol, with a view to identifying interventions that could reduce or attenuate drug-induced liver toxicity. A novel noncoding RNA that reduced paracetamol-induced hepatocyte toxicity was identified. These findings may represent an important advance for the field.

Hepatitis C Genotype Prevalence in Monastir Region, Tunisia: Correlation between 5' Untranslated Region (5'UTR), Non-structural 5B (NS5B), and Core Sequences in HCV Subtyping

Hepatitis C virus (HCV) is a causative agent of chronic liver disease, cirrhosis, and hepatocellular carcinoma. It constitutes a major public health around the world. There is no vaccine available against HCV, and current therapies are effective in only small percentage of patients. HCV has wide population-specific genotype variability. Genotype knowledge and viral load assessment are equally important for designing therapeutic strategies. Taking into account that the molecular epidemiology of HCV variants circulating in Tunisia is not yet well elucidated, and that, at present, little is known about the distribution pattern of HCV in Monastir region (Tunisia), we aimed, herein, to evaluate the prevalence of HCV genotypes in Monastir and to identify risk-related factors. For this purpose, 50 anti-HCV antibody-positive cases were diagnosed and subjected to viral RNA extraction, amplification, genotyping, and viral load quantification. Molecular epidemiology was studied by 5' untranslated region (5' UTR) sequencing as compared with the non-structural 5B (NS5B) and core region sequences. Overall concordance between 5' UTR, core, and NS5B sequencing was 100 %. The highest prevalent genotype was 1b (50 %) followed by genotypes 1a (16 %), 4a (12 %), 2a (10 %), 2c (8 %), and 3a (4 %). Interestingly, the subtype 1b had a statistically significant higher viral load than the other genotypes followed by subtype 1a. Based on these data, this study revealed a high prevalence of HCV genotype 1 (subtypes 1b and 1a) compared to other genotypes. A continued monitoring of HCV and knowledge of circulating genotypes could impact on future vaccine formulations.

Influence of Host and Viral Factors on Patients with Chronic Hepatitis C Virus Genotype 6 Treated with Pegylated Interferon and Ribavirin: A Systematic Review and Meta-Analysis

OBJECTIVES

We conducted a systematic review and meta-analysis of the influence of host and viral factors on the sustained virologic response (SVR) in hepatitis C virus genotype 6 (HCV-6) patients treated with pegylated interferon (PEG-IFN) and ribavirin (RBV).

METHODS

Data were retrieved from Medline, Embase, PubMed and the Cochrane Library for 'genotype 6' studies published up to December 2014 and for abstracts from international scientific meetings. Inclusion criteria were efficacy of PEG-IFN+RBV based on SVR, 24- or 48-week therapy and treatment-naïve patients. Patients with hepatitis B, D and E and HIV coinfection or another concurrent liver disease were excluded. Pooled standard difference, odds ratio and confidence intervals (CIs) were calculated using a random-effect model with STATA 11.

RESULTS

Fourteen studies were included in the meta-analysis. The pooled SVR rate was 80% (95% CI: 0.78-0.83, p < 0.0001; I2 = 71.2%). SVR of the PEG-IFN+RBV-treated HCV-6 patients was markedly higher than that of HCV-1 patients (80.1 vs. 55.3%). The SVR rate was significantly higher for the 48- than the 24-week treatment, but not different among HCV-infected patients with rs12979860 and ss469415590 polymorphisms of the ILFN4 gene (80.6% CC vs. 66.7% non-CC, p = 0.593; 81.1% TT/TT vs. 60% non-TT/TT, p = 0.288). Gender and type of PEG-IFN did not affect SVR rates.

CONCLUSIONS

Treatment outcomes for HCV-6 patients are superior to those for HCV-1 patients and comparable to those of HCV-2 and HCV-3 patients, especially at 48 weeks. The level of fibrosis affects treatment outcome, but SVR rates are not significantly different between genders. IL28B and IFNL4 polymorphisms are not significantly associated with HCV-6 treatment outcome.

Sofosbuvir plus ribavirin for the treatment of patients with chronic genotype 1 or 6 hepatitis C virus infection in Hong Kong

BACKGROUND

In Hong Kong, most patients with hepatitis C virus (HCV) have either genotype 6a or 1b infection.

AIM

To evaluate the efficacy and safety of sofosbuvir with ribavirin in treatment-naïve patients in Hong Kong with HCV genotype 1 or 6.

METHODS

In an open-label study, patients were randomised to sofosbuvir 400 mg once daily plus ribavirin 1000-1200 divided twice daily for 12 (n = 10), 16 (n = 11) or 24 (n = 10) weeks. The primary endpoint was the percentage of patients with HCV RNA < LLOQ (lower limit of quantification, 25 IU/mL) 12 weeks after cessation of therapy (SVR12).

RESULTS

All 31 patients (20 HCV genotype 1 and 11 genotype 6) had HCV RNA < LLOQ by Week 4 of treatment and at their last on-treatment visit. SVR12 rates were high in all treatment groups: 100% (10/10) for 12 weeks, 100% (11/11) for 16 weeks and 90% (9/10) for 24 weeks of therapy. The only patient who did not reach SVR12 had genotype 1 HCV and relapsed at post-treatment Week 4. Sofosbuvir with ribavirin was generally well tolerated. The most common adverse events were malaise (13%) and upper respiratory tract infection (13%), followed by anaemia (10%). No patients experienced serious adverse events. One patient discontinued treatment at Week 16 because of an adverse event. The event, upper respiratory tract infection, was not considered treatment related by the investigator. This subject achieved SVR12.

CONCLUSIONS

The all-oral regimen sofosbuvir plus ribavirin is effective in treatment-naïve patients in Hong Kong with genotype 1 or 6 HCV.

TRIAL REGISTRATION NUMBER

NCT02021643.

The genotype distribution of hepatitis C in southeastern Taiwan: Clinical characteristics, racial difference, and therapeutic response

The genotypes of hepatitis C virus (HCV) are associated with the therapeutic response. The racial diversity of Taitung, Taiwan is heterogeneous and a distinguishing feature; how such racial differences influence the genotype distribution and treatment outcome has not been well studied. The objective of this study is to elucidate the HCV genotype distribution in southeastern Taiwan and to analyze the racial differences influencing genotypes and clinical implications. In this retrospective cohort study, we included 343 patients who had been treated with peginterferon-alpha plus ribavirin. The predominant HCV genotype in the southeastern area was type 1 (43.7%), followed by type 2 (37.0%). The proportion of patients mixed with genotype 1 was lower in indigenous vis-à-vis nonindigenous groups (46.1% and 60.2%, p = 0.02). The prevalence of genotype 6 (5.2%) seems higher than in the general population of Taiwan and showed no difference between indigenous and nonindigenous people. The sustained virological response rate was higher in patients without genotype 1, low baseline HCV RNA (≤ 400,000 IU/mL), and in patients who achieved rapid virological response. Racial differences did not influence the therapeutic response. In this retrospective study, the proportion of HCV genotype 6 appeared slightly higher in southeastern areas than in the general population in Taiwan. The prevalence of genotype 1 in indigenous people was statistically lower than in nonindigenous people. Sustained virological response rate did not show any significant difference between indigenous and nonindigenous people in the current study.

Efficacy of ledipasvir and sofosbuvir, with or without ribavirin, for 12 weeks in patients with HCV genotype 3 or 6 infection

BACKGROUND & AIMS

We performed a phase 2 clinical trial to evaluate the efficacy and safety of ledipasvir and sofosbuvir, with or without ribavirin, in patients infected with hepatitis C virus (HCV) genotype 3 or 6.

METHODS

We performed an open-label study of 126 patients with HCV genotype 3 or 6 infections at 2 centers in New Zealand from April 2013 through October 2014. Subjects were assigned 1 of 4 groups that received 12 weeks of treatment. Previously untreated patients with HCV genotype 3 were randomly assigned to groups given fixed-dose combination tablet of ledipasvir and sofosbuvir (n = 25) or ledipasvir and sofosbuvir along with ribavirin (n = 26). Treatment-experienced patients with HCV genotype 3 (n = 50) received ledipasvir and sofosbuvir and ribavirin. Treatment-naïve or treatment-experienced patients with HCV genotype 6 (n = 25) received ledipasvir and sofosbuvir. The primary end point was the percentage of patients with HCV RNA ≤15 IU/mL 12 weeks after stopping therapy (sustained virologic response at 12 weeks [SVR12]).

RESULTS

Among treatment-naïve genotype 3 patients, 16 of 25 (64%) receiving ledipasvir and sofosbuvir alone achieved SVR12 compared with all 26 patients (100%) receiving ledipasvir and sofosbuvir and ribavirin. Among treatment-experienced patients with HCV genotype 3, forty-one of fifty achieved an SVR12 (82%). Among patients with HCV genotype 6, the rate of SVR12 was 96% (24 of 25 patients). The most common adverse events were headache, upper respiratory infection, and fatigue. One patient with HCV genotype 3 discontinued ledipasvir and sofosbuvir because of an adverse event (diverticular perforation), which was not considered treatment related.

CONCLUSIONS

In an uncontrolled, open-label trial, high rates of SVR12 were achieved by patients with HCV genotype 3 infection who received 12 weeks of ledipasvir and sofosbuvir plus ribavirin, and by patients with HCV genotype 6 infection who received 12 weeks of sofosbuvir and ledipasvir without ribavirin. Current guidelines do not recommend the use of ledipasvir and sofosbuvir, with or without ribavirin, in patients with HCV genotype 3 infection. ClinicalTrials.gov Number: NCT01826981.

Injecting drug use: A vector for the introduction of new hepatitis C virus genotypes

Hepatitis C virus (HCV) genotypes’ monitoring allows real-time insight into the dynamic changes that occur in the global epidemiological picture of HCV infection. Intravenous drug use is currently the primary driver for HCV transmission in developed and developing countries. The distribution of HCV genotypes/subtypes differs significantly between people who inject drugs (PWID) and the general population. HCV genotypes that previously exhibited a limited geographical distribution (3a, 4) are becoming more prevalent in this high-risk group. Immigration from HCV-endemic countries and the evolving networks of HCV transmission in PWID influence HCV genotypes distribution in Europe. Social vulnerabilities (e.g., unemployment, homelessness, and limited access to social and healthcare insurances systems) are important triggers for illicit drug use, which increases the associated risks of HCV infection and the frequent emergence of less prevalent genotypes. Genotype/subtype determination bears important clinical consequences in the progression of liver disease, susceptibility to antiviral therapies and the emergence of resistance-associated variants. An estimated half of the chronically HCV-infected PWID are unaware of their infection, and only one in ten of those diagnosed enter treatment. Nevertheless, PWID exhibit high response rates to new antiviral regimens, and the level of HCV reinfection is unexpectedly low. The focus of the healthcare system must be on the early detection and treatment of infection, to avoid late presentations that are associated with high levels of viremia and liver fibrosis, which may diminish the therapeutic success rate.

Accurate genotyping of hepatitis C virus through nucleotide sequencing and identification of new HCV subtypes in China population

Nucleotide sequencing of the phylogenetically informative region of NS5B remains the gold standard for hepatitis C virus (HCV) genotyping. Here we developed a new methodology for sequencing new NS5B regions to increase the accuracy and sensitivity of HCV genotyping and subtyping. The eight new primers were identified by scanning the full-length NS5B regions from 1127 HCV genomic sequences found in HCV databases. The ability of each pair of primers to amplify HCV subtypes was scored, and the new primers were able to amplify the NS5B region better than the previously used primers, therefore more accurately subtyping HCV strains. Sequencing the DNA amplified by the new primer pairs can specifically and correctly detect the five standard HCV subtypes (1a, 2a, 3b, 6a and 1b). We further examined patient samples and found that the new primers were able to identify HCV subtypes in clinical samples with high sensitivity. This method was able to detect all subtypes of HCV in 567 clinical samples. Importantly, three novel HCV subtypes (1b-2a, 1b-2k and 6d-6k) were identified in the samples, which have not been previous reported in China. In conclusion, sequencing the NS5B region amplified by the new NS5B primers is a more reliable method of HCV genotyping and a more sensitive diagnostic tool than sequencing using the previously described primers, and could identify new HCV subtypes. Our research is useful for clinical diagnosis, guidance of clinical treatment, management of clinical patients, and studies on the epidemiology of HCV.

The correlation between hepatitis C core antigen and hepatitis C virus RNA levels with respect to human immunodeficiency virus status, hepatitis C virus genotype and interferon-lambda-4 polymorphism

OBJECTIVES

Serum hepatitis C virus (HCV) core antigen (HCVcAg) concentrations correlate with HCV RNA levels in HCV monoinfected patients. Data in HCV/HIV coinfected patients are still limited. We aim to compare the use of HCVcAg measurement with respect to HIV status, HCV genotypes, interferon-lambda-4 (IFNL4) polymorphism and clinical parameters.

METHODS

We analyzed an untreated cohort of 104 patients with HCV monoinfection and 85 patients with HCV/HIV coinfection. Serum HCVcAg was measured by a commercial chemiluminescent microparticle immunoassay. The presence of IFNL4 polymorphism ss469415590 was identified by real-time PCR.

RESULTS

log10 HCVcAg levels were significantly correlated with corresponding log10 HCV RNA levels (r = 0.889, p < 0.001), but not with ALT levels and liver stiffness. The correlation between HCV RNA and HCVcAg was particularly high in coinfected patients and those with high viremia. Mean log10 HCVcAg concentration was significantly higher in coinfected patients than in monoinfected patients. Patients harboring the TT/TT genotype of ss469415590 had significantly higher levels of log10 HCVcAg than those with the non-TT/TT genotype. HCVcAg levels were similar across HCV genotypes.

CONCLUSIONS

HCVcAg concentrations had an excellent correlation with HCV RNA levels, particularly in HCV/HIV-coinfected individuals and might be associated with IFNL4 polymorphism. HCVcAg testing could be used as an alternative to HCV RNA assays in resource-limited settings.