Natural history of HCV infection

Distribution and changes in hepatitis C virus genotype in China from 2010 to 2020

BACKGROUND

Hepatitis C virus (HCV) causes a large number of infections worldwide. New infections seem to be increasing according to a report of the World Health Organization in 2015. Although direct-acting antivirals are quite effective for most genotypes of the HCV, some genotypes fail to respond. Therefore, the trend of genotype distribution is vital to better control the development of this infection.

AIM

To analyze the distribution and trends of the HCV genotype before and after the emergence of direct-acting antivirals in China.

METHODS

We searched all literature published in five electronic databases-China National Knowledge Infrastructure, Wan Fang Data, VIP Chinese Journal Database, Chinese Biomedical Literature Service System, and PubMed-from January 1, 2010 to December 31, 2020. The search strategy combined medical subject headings and free-text terms, including “hepatitis C virus” or “HCV” and “genotype” or “subtype” and ”China” or “Chinese”. Additional relevant articles were searched by manual selection. Data were extracted to build a database. All of the data were totaled according to regions, periods, routes of transmission, and sexes. The percentages in various stratifications were calculated.

RESULTS

There were 76110 samples from 30 provinces included in the study. Genotype 1 (G1) accounted for 58.2% of cases nationwide, followed by G2, G6, G3b, G3a, unclassified and mixed infections (17.5%, 7.8%, 6.4%, 4.9%, 1.8%, and 1.2%, respectively). The constitution of genotype varied among different regions, with G6 and G3b being more common in the south and southwest, respectively (28.1%, 15.4%). The past ten years have witnessed a decrease in G1 and G2 and an increase in G3 and G6 in almost all regions. The drug-use population had the most abundant genotypes, with G6 ranking first (33.3%), followed by G1 and G3b (23.4%, 18.5%).

CONCLUSION

G3 and G6 pose a new challenge for HCV infection. This study revealed the distribution of HCV genotypes in China over the past 10 years, providing information for HCV management strategies.

Best practice recommendations for the use of hepatitis C viremic donor organs for hepatitis C virus naïve recipients

The combination of the transplant organ deficit, the increase in HCV nucleic acid positive donors (HCV NAT+), and the development of direct-acting antiviral agents (DAAs) has resulted in a rapid increase in HCV NAT+ organ transplants into HCV naïve recipients. Early clinical experience with HCV NAT+ donor organs has shown promising outcomes; however, best practices are lacking to guide transplant programs during all phases of patient care. Transplant programs developing protocols for the utilization of HCV NAT+ organs will need a multidisciplinary team to address all aspects of pre-transplant and post-transplant patient care. Reports of fibrosing cholestatic hepatitis in HCV NAT+ organ transplant recipients receiving delayed DAA initiation highlight the need for the transplant community to develop safe and effective protocols. A failure to do so will inevitably lead to the erosion of public trust from cases of missed or inadequately treated donor-derived HCV infections. Herein, we provide best practice guidelines for the utilization of HCV NAT+ organs into HCV-negative recipients based on literature review and expert opinion from the faculty of the ASTS Standards and Quality Committee.

Use of healthcare resources and drug expenditure before and after treatment of chronic hepatitis C with direct antiviral agents

The aim of this study was to analyse the impact of treating chronic hepatitis C (CHC) with direct-acting agents (DAA) on the use of healthcare resources. We included all patients treated with DAA for CHC from January 2015 to December 2017 in Catalonia whose medical records from 12 months before to 24 months after treatment were available. Data were obtained from the Catalan Health Surveillance System. A total of 12,199 patients in Catalonia were treated with DAA for CHC. Of these, 11.3% had no-minimal fibrosis (F0-F1), 24.0% had moderate fibrosis (F2), 50.3% had significant fibrosis or cirrhosis (F3-F4), and 14.4% had decompensated cirrhosis. Use of healthcare resources decreased from the pre-treatment period to the post-treatment period for the following: hospital admissions due to complications of cirrhosis, from 0.19 to 0.12 per month per 100 patients (RR 0.57; 95% CI 0.47-0.68); length of hospital stay, from 12.9 to 12.2 days (RR 0.93; 95% CI 0.91-0.94); outpatient visits, from 65.0 to 49.2 (RR 0.75; 95% CI 0.74-0.75); and number of medication containers per patient per month, from 13.9 to 12.5 (RR 0.837; 95% CI 0.835-0.838). However, the number of invoices for antineoplastic treatment increased after DAA treatment, especially for patients with high morbidity or advanced fibrosis stage. In conclusion, a decrease in health resource use was seen in CHC patients treated with DAA, as measured by length of hospital stay, number of admissions due to cirrhosis complications, outpatient visits and overall drug invoicing. However, use of antineoplastic drugs increased significantly, especially in patients with cirrhosis and high morbidity.

Comparison of double antigen sandwich and indirect enzyme-linked immunosorbent assay for the diagnosis of hepatitis C virus antibodies

BACKGROUND

The aim of this study is to compare double-antigen sandwich enzyme-linked immunosorbent assay (ELISA) and indirect ELISA in the diagnosis of hepatitis C virus（HCV）infection.

METHODS AND MATERIALS

A total of 176 samples from the Tumor Hospital Affiliated to Xin Jiang Medical University were utilized to comparison. All serum samples were tested using double-antigen sandwich ELISA and indirect ELISA. Cohen's kappa statistics were used to assess the agreement between the two assays, and multivariate analysis was used to evaluate risk factors for the discordance between the double-antigen ELISA and indirect ELISA.

RESULTS

The positivities of indirect ELISA (Beijing Wantai), double-antigen sandwich ELISA (Beijing Wantai), and indirect ELISA (Beijing Jinhao) were 74.43%, 68.75%, and 73.30%, respectively. The agreement between the indirect ELISA (Beijing Wantai) and double-antigen sandwich ELISA (Beijing Wantai) was high (κ = 0.829;P < .001), and the agreement between the double-antigen sandwich ELISA (Beijing Wantai) and indirect ELISA (Beijing Jinhao) was high (κ = 0.847;P < .001). Variables associated with discordant results between the double-antigen sandwich and indirect ELISA in multivariate analysis were as follows: female (OR:1.462; P < .05), age (<35 years old; OR:3.667; P < .05), and cancer (suffer from malignant tumor; OR:3.621; P < .05).

CONCLUSION

In detection of HCV, high agreement was found between the double-antigen sandwich ELISA and indirect ELISA. Female, younger age, and suffer from malignant tumor were significant risk factors for the discordance. Based on double-antigen sandwich ELISA has distinct methodological advantages over indirect ELISA. It is recommended for the diagnosis of HCV infection.

Tumor necrosis family receptor superfamily member 9/tumor necrosis factor receptor-associated factor 1 pathway on hepatitis C viral persistence and natural history

Hepatitis C virus (HCV) infection is an excellent immunological model for understanding the mechanisms developed by non-cytopathic viruses and tumors to evade the adaptative immune response. The antigen-specific cytotoxic T cell response is essential for keeping HCV under control, but during persistent infection, these cells become exhausted or even deleted. The exhaustion process is progressive and depends on the infection duration and level of antigenemia. During high antigenic load and long duration of infection, T cells become extremely exhausted and ultimately disappear due to apoptosis. The development of exhaustion involves the impairment of positive co-stimulation induced by regulatory cytokines, such as transforming growth factor beta 1. This cytokine downregulates tumor necrosis factor receptor (TNFR)-associated factor 1 (TRAF1), the signal transducer of the T cell co-stimulatory molecule TNFR superfamily member 9 (known as 4-1BB). This impairment correlates with the low reactivity of T cells and an exhaustion phenotype. Treatment with interleukin-7 in vitro restores TRAF1 expression and rescues T cell effector function. The process of TRAF1 loss and its in vitro recovery is hierarchical, and more affected by severe disease progression. In conclusion, TRAF1 dynamics on T cells define a new pathogenic model that describes some aspects of the natural history of HCV, and sheds light on novel immunotherapy strategies for chronic viral infections and cancer.

Animal Models Used in Hepatitis C Virus Research

The narrow range of species permissive to infection by hepatitis C virus (HCV) presents a unique challenge to the development of useful animal models for studying HCV, as well as host immune responses and development of chronic infection and disease. Following earlier studies in chimpanzees, several unique approaches have been pursued to develop useful animal models for research while avoiding the important ethical concerns and costs inherent in research with chimpanzees. Genetically related hepatotropic viruses that infect animals are being used as surrogates for HCV in research studies; chimeras of these surrogate viruses harboring specific regions of the HCV genome are being developed to improve their utility for vaccine testing. Concurrently, genetically humanized mice are being developed and continually advanced using human factors known to be involved in virus entry and replication. Further, xenotransplantation of human hepatocytes into mice allows for the direct study of HCV infection in human liver tissue in a small animal model. The current advances in each of these approaches are discussed in the present review.

Hepatitis C infection: Updates on treatment guidelines

Hepatitis C virus (HCV) is a major cause of chronic liver disease worldwide. Due to the asymptomatic nature of the infection, many acute cases of HCV infection are left undiagnosed, so screening individuals at risk is an important public health priority. New medications offer sustained virologic response rates of over 95%, fewer adverse reactions, and shorter durations of therapy. This article reviews the new treatment guidelines for the evaluation and management of patients with HCV infection.

Dysregulation of fibrosis related genes in HCV induced liver disease

BACKGROUND

Liver fibrosis results from a wound healing response to chronic injury, which leads to excessive matrix deposition. Genome wide association studies have showen transcriptional dysregulation in mild and severe liver fibrosis. Recent studies suggested that genetic markers may be able to define the exact stage of liver fibrosis.

AIM

To define genes or genetic pathways that could serve as markers for staging or as therapeutic targets to halt progression of liver fibrosis.

METHODS

The study was performed on 105 treatment naïve HCV genotype 4 infected patients [F0-F2, n = 56; F3-F4, n = 49] and 16 healthy subjects. The study included PCR array on 84 fibrosis related genes followed by customization of a smaller array consisting of 11 genes that were designed on the bases of results obtained from the larger array. Genes that displayed significant dysregulation at mRNA levels were validated at protein levels.

RESULTS AND DISCUSSION

Two major pathways exhibited high dysregulation in early fibrosis as compared with controls or when compared with late fibrosis, these were the TGFβ - related pathway genes and Matrix - deposition associated genes. Hepatic stellate cell (HSC) activators i.e. TGFβ pathway genes [TGFβ1, 2 and 3, their receptors TGFβR1 and 2, signaling molecules SMAD genes and PDGF growth factors] were considerably over-expressed at transcriptional levels as early as F0, whereas expression of their inhibitor TGIF1 was simultaneously down regulated. Matrix proteins including collagen and MMPs were upregulated in early fibrosis whereas tissue inhibitors TIMPs 1 and 2 began over expression in late fibrosis. Expression at protein levels was concordant with RNA data excluding dysregulation at post transcriptional levels.

CONCLUSION

Since these 2 gene sets are closely interrelated regarding HSC activation and proliferation, we assume that the current findings suggest that they are favorable targets to further search for stage specific markers.

Effects of caffeine consumption in patients with chronic hepatitis C: A systematic review and meta-analysis

BACKGROUND

Increased caffeine consumption has been associated with a decreased risk of liver enzyme elevation, cirrhosis, and hepatocellular carcinoma. However, few studies have assessed these effects in patients with chronic hepatitis C; therefore, we conducted a systematic review and meta-analysis to investigate the impact of caffeine consumption in patients with chronic hepatitis C infection.

METHODS

We performed a comprehensive search of the databases of the Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE from inception through November 2015. The inclusion criterion was observational studies' assessment of the impact of caffeine consumption in adult patients with chronic hepatitis C.

RESULTS

Eleven studies were included for full article review, and data was extracted from five observational studies for meta-analysis. The pooled odds ratio of advanced hepatic fibrosis in patients who had higher caffeine intake was 0.39 (95% confidence interval 0.21-0.72, P=0.003) compared with lower caffeine intake group. The statistical between-study heterogeneity was moderate with an I² of 70%.

CONCLUSIONS

Our meta-analysis demonstrated that caffeine intake is significantly associated with decreased odds of advanced hepatic fibrosis in patients with chronic hepatitis C. Future prospective studies assessing the optimal dose and preparation of caffeinated beverages for prevention of hepatic fibrosis are needed.

Point -of -care testing (POCT) in molecular diagnostics: Performance evaluation of GeneXpert HCV RNA test in diagnosing and monitoring of HCV infection

BACKGROUND

Molecular testing at the point-of-care may turn out to be game changer for HCV diagnosis and treatment monitoring, through increased sensitivity, reduced turnaround time, and ease of performance. One such assay GeneXpert^® has recently been released.

OBJECTIVES

Comparative analysis between performances of GeneXpert^® and Abbott HCV-RNA was done.

STUDY DESIGN

174 HCV infected patients were recruited and, one time plasma samples from 154 patients and repeated samples from 20 patients, obtained at specific treatment time-points (0, 4, 12 and 24) weeks were serially re-tested on Xpert^®.

RESULTS

Genotype 3 was the commonest, seen in 80 (66%) of the cases, genotype 1 in 34 (28.3%), genotype 4 in 4 (3.3%) and genotypes 2 and 5 in 1 (0.8%) each. Median HCV RNA load was 4.69 log₁₀ (range: 0-6.98log₁₀) IU/ml. Overall a very good correlation was seen between the two assays (R²=0.985), concordance of the results between the assays was seen in 138 samples (89.6%). High and low positive standards were tested ten times on Xpert^® to evaluate the precision and the coefficient of variation was 0.01 for HPC and 0.07 for the LPC. Monitoring of patients on two different regimes of treatment, pegylated interferon plus ribavirin and sofosbuvir plus ribavirin was done by both the systems at baseline, 4, 12 and 24 weeks. Perfect correlation between the assays in the course of therapy at different treatment time- point in genotypes 3 and 1 was seen.

CONCLUSION

The study demonstrates excellent performance of the Xpert^® HCV assay in viral load assessment and in treatment course monitoring consistency.

Clinical epidemiology of acute hepatitis C in South America

There is scarce data pertaining to acute hepatitis C (aHC) infection in South America. We aimed to describe clinical characteristics and evolution of aHC in a South American cohort. A retrospective survey was conducted at 13 hepatology units. All patients ≥16 years old with aHC diagnosis were included. Demographic, clinical and outcome information were registered in a standardized ad hoc questionnaire. Sixty-four patients were included. The majority were middle-aged (median age: 46 years) and female (65.6%); most of them were symptomatic at diagnosis (79.6%). HCV-1 was the most prevalent genotype (69.2%). Five patients had liver failure: three cases of severe acute hepatitis, one case of fulminant hepatitis and one case of acute-on-chronic liver failure. Nosocomial exposure was the most prevalent risk factor. Evolution was assessed in 46 patients. In the untreated cohort, spontaneous resolution occurred in 45.8% and was associated with higher values of AST/ALT and with the absence of intermittent HCV RNA viremia (P = 0.01, 0.05, and 0.01, respectively). In the treated cohort, sustained virological response was associated with nosocomial transmission and early treatment initiation (P = 0.04 each). The prevalence of nosocomial transmission in this South-American cohort of aHC stresses the importance of following universal precautions to prevent HCV infection. J. Med. Virol. 89:276-283, 2017. © 2016 Wiley Periodicals, Inc.

Gene therapies for hepatitis C virus

Hepatitis C virus (HCV) is a leading cause of chronic hepatitis and infects approximately three to four million people per year, about 170 million infected people in total, making it one of the major global health problems. In a minority of cases HCV is cleared spontaneously, but in most of the infected individuals infection progresses to a chronic state associated with high risk to develop liver cirrhosis, hepatocellular cancer, or liver failure. The treatment of HCV infection has evolved over the years. Interferon (IFN)-α in combination with ribavirin has been used for decades as standard therapy. More recently, a new standard-of-care treatment has been approved based on a triple combination with either HCV protease inhibitor telaprevir or boceprevir. In addition, various options for all-oral, IFN-free regimens are currently being evaluated. Despite substantial improvement of sustained virological response rates, some intrinsic limitations of these new direct-acting antivirals, including serious side effects, the risk of resistance development and high cost, urge the development of alternative or additional therapeutic strategies. Gene therapy represents a feasible alternative treatment. Small RNA technology, including RNA interference (RNAi) techniques and antisense approaches, is one of the potentially promising ways to investigate viral and host cell factors that are involved in HCV infection and replication. With this, newly developed gene therapy regimens will be provided to treat HCV. In this chapter, a comprehensive overview guides you through the current developments and applications of RNAi and microRNA-based gene therapy strategies in HCV treatment.

Treatment of hepatitis C virus infection in the future

Two direct-acting antivirals (DAAs) against hepatitis C virus (HCV): telaprevir and boceprevir, are now available in combination with peginterferon plus ribavirin for the treatment of chronic hepatitis C infection. Although these drugs are potent inhibitors of HCV replication, they occasionally result in severe adverse events. In the present clinical trials, in their stead, several second-generation DAAs are being investigated. Most of them are being viewed with high expectations, but they also require the combination with peginterferon plus ribavirin. In the near future, we might be using all-oral DAAs and interferon-free regimens for the treatment of HCV-infected patients, and these would be potent inhibitors of HCV and have less adverse events.