Detection of antibody to hepatitis C virus in prospectively followed transfusion recipients with acute and chronic non-A, non-B hepatitis

Viral Hepatitis C: From Unraveling the Nature of Disease to Cure and Global Elimination

BACKGROUND

The discovery of the hepatitis C virus (HCV) and direct-acting antiviral (DAA) drugs is one of the major milestones in the last 3 decades of medicine. These discoveries encouraged the World Health Organization (WHO) to set an ambitious goal to eliminate HCV by 2030, meaning "a 90% reduction in new cases of chronic HCV, a 65% reduction in HCV deaths, and treatment of 80% of eligible people with HCV infections."

SUMMARY

This review summarizes the key achievements from the discovery of HCV to the development of effective treatment and global elimination strategies. A better understanding of HCV structure, enzymes, and lifecycle led to the introduction of new drug targets and the discovery of DAA. Massive public health interventions are required, such as screening, access to care, treatment, and post-care follow-up, to make the most of DAA's potential. Screening must be supported by fast, accessible, sensitive, specific HCV diagnostic tests and noninvasive methods to determine the stage of liver disease. Linkage to care and treatment access are critical components of a comprehensive HCV elimination program, and decentralization plays a key role in ensuring their effectiveness.

KEY MESSAGES

Effective and simple screening strategies, rapid diagnostic tools, linkage to health care, and accessible treatment are key elements to achieving the WHO's goal. Incorporating treatment as prevention strategies into elimination programs together with preventive education and harm reduction interventions can have a profound and lasting impact on reducing both the incidence and prevalence of HCV. However, WHO's goal can be challenging to implement because of the need for high financial resources and strong political commitment.

Biomarkers in Detection of Hepatitis C Virus Infection

The hepatitis C virus (HCV) infection affects 58 million people worldwide. In the United States, the incidence rate of acute hepatitis C has doubled since 2014; during 2021, this increased to 5% from 2020. Acute hepatitis C is defined by any symptom of acute viral hepatitis plus either jaundice or elevated serum alanine aminotransferase (ALT) activity with the detection of HCV RNA, the anti-HCV antibody, or hepatitis C virus antigen(s). However, most patients with acute infection are asymptomatic. In addition, ALT activity and HCV RNA levels can fluctuate, and a delayed detection of the anti-HCV antibody can occur among some immunocompromised persons with HCV infection. The detection of specific biomarkers can be of great value in the early detection of HCV infection at an asymptomatic stage. The high rate of HCV replication (which is approximately 1010 to 1012 virions per day) and the lack of proofreading by the viral RNA polymerase leads to enormous genetic diversity, creating a major challenge for the host immune response. This broad genetic diversity contributes to the likelihood of developing chronic infection, thus leading to the development of cirrhosis and liver cancer. Direct-acting antiviral (DAA) therapies for HCV infection are highly effective with a cure rate of up to 99%. At the same time, many patients with HCV infection are unaware of their infection status because of the mostly asymptomatic nature of hepatitis C, so they remain undiagnosed until the liver damage has advanced. Molecular mechanisms induced by HCV have been intensely investigated to find biomarkers for diagnosing the acute and chronic phases of the infection. However, there are no clinically verified biomarkers for patients with hepatitis C. In this review, we discuss the biomarkers that can differentiate acute from chronic hepatitis C, and we summarize the current state of the literature on the useful biomarkers that are detectable during acute and chronic HCV infection, liver fibrosis/cirrhosis, and hepatocellular carcinoma (HCC).

The association between alcohol, betel nut, and cigarette use with hepatitis C virus infection in Taiwan

Hepatitis C virus (HCV) infection may cause chronic liver disease, liver cirrhosis, and liver cancer. It has been reported to associate with habits including alcohol, betel nut and cigarette use. We aimed to investigate the association between alcohol, betel nut, and cigarette use with HCV infection in Taiwan and to explore their effects. A total of 121,421 participants were enrolled from the Taiwan Biobank. They were stratified into two groups according to whether they had (n = 2750; 2.3%) or did not have (n = 118,671; 97.7%) HCV infection. All participants were also classified into four groups according to the number of habits, including a history of alcohol drinking, betel nut chewing, and cigarette smoking. There were 85,406 (no habit), 24,299 (one habit), 8659 (two habits), and 3057 (three habits) participants in the four groups, respectively. Multivariable analysis showed that the participants who had an alcohol drinking history (odds ratio [OR] 1.568; 95% confidence interval [CI] 1.388-1.773; p < 0.001), betel nut chewing history (OR 1.664; 95% CI 1.445-1.917; p < 0.001), cigarette smoking history (OR 1.387; 95% CI 1.254-1.535; p < 0.001), were significantly associated with HCV infection. Furthermore, the participants were classified into four groups according to the number of habits as follows: 85,406 (no habit), 24,299 (one habit), 8659 (two habits), and 3057 (three habits). The HCV infection rates in these four groups were 2.11%, 2.14%, 3.23%, and 4.78%, respectively. Compared to the participants with no or one habit, those with two habits had a higher HCV infection rate (all p < 0.001). In addition, compared to the participants who had no, one or two habits, those who had three habits also had higher HCV infection rates (all p < 0.001). The participants who had three habits had the highest prevalence of HCV infection. In an era when most HCV can be cured, understanding the epidemiology link between habits and HCV may help the case finding.

Leveraging Donor Populations to Study the Epidemiology and Pathogenesis of Transfusion-Transmitted and Emerging Infectious Diseases

The tragedy of transfusion-associated hepatitis and HIV spurred a decades-long overhaul of the regulatory oversight and practice of blood transfusion. Consequent to improved donor selection, testing, process control, clinical transfusion practice and post-transfusion surveillance, transfusion in the United States and other high-income countries is now a very safe medical procedure. Nonetheless, pathogens continue to emerge and threaten the blood supply, highlighting the need for a proactive approach to blood transfusion safety. Blood donor populations and the global transfusion infrastructure are under-utilized resources for the study of infectious diseases. Blood donors are large, demographically diverse subsets of general populations for whom cross-sectional and longitudinal samples are readily accessible for serological and molecular testing. Blood donor collection networks span diverse geographies, including in low- and middle-income countries, where agents, especially zoonotic pathogens, are able to emerge and spread, given limited tools for recognition, surveillance and control. Routine laboratory storage and transportation, coupled with data capture, afford access to rich epidemiological data to assess the epidemiology and pathogenesis of established and emerging infections. Subsequent to the State of the Science in Transfusion Medicine symposium in 2022, our working group (WG), "Emerging Infections: Impact on Blood Science, the Blood Supply, Blood Safety, and Public Health" elected to focus on "leveraging donor populations to study the epidemiology and pathogenesis of transfusion-transmitted and emerging infectious diseases." The 5 landmark studies span (1) the implication of hepatitis C virus in post-transfusion hepatitis, (2) longitudinal evaluation of plasma donors with incident infections, thus informing the development of a widely used staging system for acute HIV infection, (3) explication of the dynamics of early West Nile Virus infection, (4) the deployment of combined molecular and serological donor screening for Babesia microti, to characterize its epidemiology and infectivity and facilitate routine donor screening, and (5) national serosurveillance for SARS-CoV-2 during the COVID-19 pandemic. The studies highlight the interplay between infectious diseases and transfusion medicine, including the imperative to ensure blood transfusion safety and the broader application of blood donor populations to the study of infectious diseases.

Breakthroughs in hepatitis C research: from discovery to cure

In the 1970s, an unknown virus was suspected for documented cases of transfusion-associated hepatitis, a phenomenon called non-A, non-B hepatitis. In 1989, the infectious transmissible agent was identified and named hepatitis C virus (HCV) and, soon enough, the first diagnostic HCV antibody test was developed, which led to a dramatic decrease in new infections. Today, HCV infection remains a global health burden and a major cause of liver cirrhosis, hepatocellular carcinoma and liver transplantation. However, tremendous advances have been made over the decades, and HCV became the first curable, chronic viral infection. The introduction of direct antiviral agents revolutionized antiviral treatment, leading to viral eradication in more than 98% of all patients infected with HCV. This Perspective discusses the history of HCV research, which reads like a role model for successful translational research: starting from a clinical observation, specific therapeutic agents were developed, which finally were implemented in national and global elimination programmes.

Blood Product (Donor) Noninfectious and Infectious Testing and Modification

Blood transfusion begins with safe donor selection and testing. In the United States, the blood supply and transfusion are highly regulated. Blood transfusion safety is multifaceted, whereby each of the elements of the blood safety value chain, spanning donor recruitment and qualification, to collection, blood processing, testing, transfusion practice, and posttransfusion surveillance, must be optimized to minimize risk. Pathogen inactivation is a promising approach to decrease bacterial contamination of platelets, inactivate parasites and viruses, and decrease risks associated with emerging and unidentified pathogens. This article offers an overview of blood donor infectious and noninfectious testing in the United States.

Virus-Driven Carcinogenesis

Cancer arises from the accumulation of genetic and epigenetic alterations. Even in the era of precision oncology, carcinogens contributing to neoplastic process are still an important focus of research. Comprehensive genomic analyses have revealed various combinations of base substitutions, referred to as the mutational signatures, in cancer. Each mutational signature is believed to arise from specific DNA damage and repair processes, including carcinogens. However, as a type of carcinogen, tumor viruses increase the cancer risk by alternative mechanisms, including insertional mutagenesis, viral oncogenes, and immunosuppression. In this review, we summarize virus-driven carcinogenesis to provide a framework for the control of malignant cell proliferation. We first provide a brief overview of oncogenic viruses and describe their implication in virus-related tumors. Next, we describe tumor viruses (HPV, Human papilloma virus; HBV, Hepatitis B virus; HCV, Hepatitis C virus; EBV, Epstein-Barr virus; Kaposi sarcoma herpesvirus; MCV, Merkel cell polyoma virus; HTLV-1, Human T-cell lymphotropic virus, type-1) and tumor virus-related cancers. Lastly, we introduce emerging tumor virus candidates, human cytomegalovirus (CMV), human herpesvirus-6 (HHV-6) and adeno-associated virus-2 (AAV-2). We expect this review to be a hub in a complex network of data for virus-associated carcinogenesis.

Pharmacology Update for the Treatment of Hepatitis C Virus

Hepatitis C virus (HCV) is a common infectious disease affecting people worldwide. In the past 10 years, the incidence of HCV has steadily increased in the United States. With the advent of new direct-acting antiviral medications, the treatment of HCV has become important and can cure the infection.

Global hepatitis C elimination: history, evolution, revolutionary changes and barriers to overcome

The fundamental discovery of the hepatitis C virus (HCV) in 1989 has led to winning this year's Nobel Prize in Medicine. This achievement guided all the steps in identifying the elements of the virus, in order to develop the treatment and to increase the screening solutions, which have slowed the exposure to the virus. The management of infection started with interferon-alpha (IFN-α), which has later enhanced by adding Ribavirin. Nowadays, HCV treatment is based on direct-acting antiviral agents (DAAs). Currently, HCV infection benefits of curative treatment, with which most patients can be cured. When speaking about hepatitis C future, we can say it is looking bright, considering all the progress that has been made in recent years and all the options that we have for curing all genotypes of HCV infection. The aim of this review is to sum up the historical characteristics of HCV discovery, the evolution of treatment and screening actions, gaps, and stages for achieving the international elimination target of the World Health Organization.

Hepatitis C Virus and Hepatocellular Carcinoma: When the Host Loses Its Grip

Chronic infection with hepatitis C virus (HCV) is a major cause of hepatocellular carcinoma (HCC). Novel treatments with direct-acting antivirals achieve high rates of sustained virologic response; however, the HCC risk remains elevated in cured patients, especially those with advanced liver disease. Long-term HCV infection causes a persistent and accumulating damage of the liver due to a combination of direct and indirect pro-oncogenic mechanisms. This review describes the processes involved in virus-induced disease progression by viral proteins, derailed signaling, immunity, and persistent epigenetic deregulation, which may be instrumental to develop urgently needed prognostic biomarkers and as targets for novel chemopreventive therapies.

Prevalence of Hepatitis c Antibodies (HCV) in a Dialysis Population at One Center

Hepatitis C (HC) has been recently diagnosed by determination of specific antibodies that represent the former so-called non-A, non-B hepatitis.

We studied the prevalence of plasma HCV antibodies among 61 unselected patients on hemodialysis (HD) and 43 on continuous ambulatory peritoneal dialysis (CAPD). Plasma C-antibodies were determined through the ELISA test system. Transfusion policy was the same in both groups.

The prevalence of hepatitis C virus antibodies was significantly higher in hemodialysis patients than among those on CAPD. Time on dialysis, previous blood transfusions, and renal transplantation seem to increase the prevalence of C hepatitis antibodies among hemodialy sis patients. The effect of these parameters on CAPD was smaller. Understanding the reasons for these differences may help prevent this disease among dialysis patients.

The Need for Second-Generation Antihepatitis C Virus Testing in Uremic Patients on Continuous Ambulatory Peritoneal Dialysis

Objective

To assess the prevalence and clinical relevance of a hepatitis C virus (HCV) infection in continuous ambulatory peritoneal dialysis (CAPD) patients by first (Ortho) and second-generation (Abbott and UBI) HCV antibody enzyme immunoassays.

Design

Thirty-two serum samples tested by first generation HCV antibody enzyme immunoassays (EIA's) were reevaluated using two second-generation HCV antibody EIA's. Basic demographic data, history of blood transfusions, and duration of hemodialysis and CAPD were reviewed. Results were analyzed by chi square analysis, Wilcoxon rank sum, and the paired t-test.

Setting

The medical college's affiliated teaching hospital.

Results

The prevalence of the antibody anti-HCV increases with the duration of previous hemodialysis, but not with the duration of CAPD. The positive detection of anti-HCV by second-generation HCV antibody EIA's was higher than first-generation EIA's (25% and 34.4% vs 12.5%).

Conclusion

The prevalence and clinical relevance of HCV infection can be more accurately studied using the second-generation assays in uremic patients.

Prevalence of Hepatitis C Antibodies (HCV) in a Dialysis Population at One Center

Hepatitis C (HC) has been recently diagnosed by determination of specific antibodies that represent the former so-called non-A, non-B hepatitis.

We studied the prevalence of plasma HCV antibodies among 61 unselected patients on hemodialysis (HD) and 43 on continuous ambulatory peritoneal dialysis (CAPD). Plasma C-antibodies were determined through the ELISA test system. Transfusion policy was the same in both groups.

The prevalence of hepatitis C virus antibodies was significantly higher in hemodialysis patients than among those on CAPD. Time on dialysis, previous blood transfusions, and renal transplantation seem to increase the prevalence of C hepatitis antibodies among hemodialy sis patients. The effect of these parameters on CAPD was smaller. Understanding the reasons for these differences may help prevent this disease among dialysis patients.

Hepatitis C Antibodies in Patients on Peritoneal Dialysis: Prevalence and Risk Factors

Our objective was to determine the prevalence of the antibody to hepatitis C (anti-HCV) in a population of endstage renal failure patients on continuous peritoneal dialysis (CPD) and study the possible risk factors associated with anti-HCV seropositivity and seroconversion. A cross-sectional study included 155 adult patients enrolled in the CPD program in a single renal unit of a teaching hospital who were screened for anti-HCV by second-generation enzyme immunoassay, which was confirmed by recombinant immunoblot assay. Serum was also assayed for hepatitis B surface antigen (HBsAg). History of renal transplantation, blood transfusions, and exposure to hemodialysis was obtained from medical records.

Ten of 155 patients (6.5%) in this study population were anti-HCV positive [anti-HCV(+)] and 11/155 (7.1%) were HBsAg positive; no patient was positive for both. All the anti-HCV(+) patients were on continuous ambulatory peritoneal dialysis (CAPD); no continuous cycling peritoneal dialysis (CCPD) patient was anti-HCV(+). Exposure to hemodialysis was a risk factor for anti-HCV seropositivity, with 7 out of 10 (70%) anti-HCV(+) patients having been on hemodialysis compared to 55/134 (41%) anti-HCV(-) (p < 0.05, Fisher's exact test). No difference was noted between anti-HCV(+) and anti-HCV(-) groups in relation to age, gender, duration on CPD, renal transplantation, or exposure to blood transfusions. Seroconversion occurred in only one patient after a mean observation period of 20±0.6 months.

The prevalence of anti-HCV seropositivity in this population of CPD patients is 6.5%, and HBsAg is 7.1%. Exposure to hemodialysis is a significant risk factor for development of anti-HCV seropositivity. Seroconversion rate appears to be low.

[Hepatitis C virus research so far and in the future]

The 2020 Nobel Prize in Physiology or Medicine was awarded to three researchers who contributed to the development of the disease concept ''non-A, non-B hepatitis'' and the isolation of its causative agent, hepatitis C virus (HCV). Technologies and experimental systems to analyze HCV have been greatly improved for these three decades, and the antiviral treatments against HCV have been developed. This review summarizes the effort to elucidate the HCV biology so far and the remaining subject to be solved in the future. I also introduce the studies to identify bioactive natural products by taking advantage of the HCV infection cell culture system.

Paediatric hepatitis C virus infection and its treatment: Present, past, and future

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease in the world. It is a challenging medico-social problem in the paediatric population. High HCV infection rates are reported in low and middle incomes countries. From the health economic point of view treatment of hepatitis C virus (HCV) with subsequent virus eradication is very effective as it eliminates the long-term sequelae of untreated or maltreated HCV. In this review we summarize the updates and highlight the historical approach of treatment of chronic HCV infection in children in the new era of directly acting antiviral (DAA) agents.

Pathology of liver disease: advances in the last 50 years

Liver disease has been recognized in various forms for centuries. Incredible advances, however, have been made especially in the last 50 years, driven by improvements in histology, the development of immunostains, the development of high resolution imaging methods, improved biopsy and resection methods, and the emergence of the molecular era. With these tools, pathologists and their clinical and basic science colleagues moved from classifying liver disease using an observational, pattern-based approach to a refined classification of disease, one based on etiology for medical disease and tumor classification for neoplastic disease. Examples of liver specific diseases are used to illustrate these exciting advances. These impressive advances of the past provide the foundation for hope in the future, as liver pathology continues to play an important role in improving patient care through disease identification and classification and emerging roles in guiding therapy for cures.

Prevalence and risk factors associated with hepatitis C among Brazilian male patients with haemophilia: A long-term follow-up

People with haemophilia represent a population with a high prevalence of HCV infection due to the use of blood components and plasma-derived clotting factor concentrates before the introduction of viral-inactivating procedures (in the 1980s) and screening for HCV (in the 1990s). About 80% of HCV-infected patients have chronic HCV infection, and at least 20% develop end-stage liver disease. The aim of the study was to assess current anti-HCV positivity in a large cohort of Brazilian haemophilia patients and to determine associated factors with HCV exposure. The study retrospectively analysed medical records of all male haemophilia patients attended the main public referral blood centre in Belo Horizonte, Brazil, from January 1985 to January 2015. Sociodemographic, epidemiological and serological characteristics were collected of all participants tested for anti-HCV. Among 724 patients enrolled in the study, anti-HCV was positive in 259 resulting in a seroprevalence of 35.8% (95% CI: 32.3%-39.3%). Factors independently associated with previous exposure to HCV were as follows: age older than 30 years, moderate to severe haemophilia, detection of inhibitor at least once in lifetime and previous exposure to hepatitis B virus (HBV) infection or HIV infection. Otherwise, exclusive previous use of inactivated clotting factors resulted in a significant decrease in the chance of positivity for anti-HCV. At the end of cohort period, patients with positive anti-HCV had a 3-fold higher risk of death. This study showed that hepatitis C infection remains a critical problem for Brazilian haemophilia patients and reinforced the need to unify efforts to eradicate it.

Osteopathic Physical Exam Findings in Chronic Hepatitis C: A Case Study

Greater than two-thirds of all Hepatitis C virus (HCV) infections are chronic, leading to extrahepatic changes in the body. The objective of this article was to describe various musculoskeletal findings that can be elicited during an osteopathic structural exam in the setting of liver dysfunction along with an overview of hepatic viscerosomatics and Chapman’s points. Osteopathic medicine is a branch of modern medicine that utilizes hands-on diagnosis and treatment through musculoskeletal manifestations in addition to the standard allopathic practices. Herein, we presented a case of untreated chronic HCV infection, complicated by polysubstance abuse, with positive findings on osteopathic physical exam consistent with hepatic pathology.

Transmission of hepatitis C virus in the dialysis setting and strategies for its prevention

Hepatitis C virus (HCV) infection is more common among hemodialysis patients than the general population and transmission of HCV in dialysis clinics has been reported. In the context of the increased morbidity and mortality associated with HCV infection in the end stage renal disease population, it is important that dialysis clinics have processes in place for ensuring recommended infection control practices, including Standard Precautions, through regular audits and training of the staff. This review will summarize the epidemiology of HCV infection and risk factors for HCV transmission among hemodialysis patients. In addition, the proper protocols are required to investigate suspected cases of HCV transmission in dialysis facilities and recommendations for prevention of HCV transmission in will be reviewed.

Engineering of the hepatitis C virus helicase for enhanced seroreactivity

Hepatitis C Virus c33, a recombinant protein comprising residues 1192-1457 of NS3 helicase, has been a mainstay of HCV serology for decades. With seven unpaired cysteines, seroreactivity of E. coli expressed c33 is dependant on reductants. While engineering a c33 replacement for new anti-HCV serological tests, we sought to reduce oxidation sensitivity, a liability for immunodiagnostic reagent stability. A series of cysteine-to-serine substituted variants of a c33-like antigen was constructed and evaluated for reactivity against a panel of HCV-positive sera. Several variants were essentially nonreactive while others exhibited reactivity similar to or better than the wild-type construct. One demonstrated equivalent potency to wild-type but also diminished DTT dependence. To explore enhanced anti-NS3 reactivity, we constructed and examined an expanded series of antigens comprising individual helicase domains, the full-length helicase, additional cysteine-to-serine variants, and variants at positions critical to catalytic activity. Immunoassays using these latter NS3 helicase recombinants demonstrated that domain 1 possessed significantly more seroreactivity than previously believed, that the use of soluble full-length helicase protein enhanced sensitivity by several-fold over c33, and that anti-NS3 helicase seroreactivity was further enhanced by the introduction of point mutations which altered the catalytic activity or oxidation sensitivity of the antigen.

Towards hepatitis C virus elimination: Egyptian experience, achievements and limitations

Worldwide, more than one million people die each year from hepatitis C virus (HCV) related diseases, and over 300 million people are chronically infected with hepatitis B or C. Egypt used to be on the top of the countries with heavy HCV burden. Some countries are making advances in elimination of HCV, yet multiple factors preventing progress; remain for the majority. These factors include lack of global funding sources for treatment, late diagnosis, poor data, and inadequate screening. Treatment of HCV in Egypt has become one of the top national priorities since 2007. Egypt started a national treatment program intending to provide cure for Egyptian HCV-infected patients. Mass HCV treatment program had started using Pegylated interferon and ribavirin between 2007 and 2014. Yet, with the development of highly-effective direct acting antivirals (DAAs) for HCV, elimination of viral hepatitis has become a real possibility. The Egyptian National Committee for the Control of Viral Hepatitis did its best to provide Egyptian HCV patients with DAAs. Egypt adopted a strategy that represents a model of care that could help other countries with high HCV prevalence rate in their battle against HCV. This review covers the effects of HCV management in Egyptian real life settings and the outcome of different treatment protocols. Also, it deals with the current and future strategies for HCV prevention and screening as well as the challenges facing HCV elimination and the prospect of future eradication of HCV.

Non-A, Non-B Hepatitis and Anti-HCV Antibodies in Dialysis Patients

To define the prevalence of non-A, non-B hepatitis, antibodies to HCV were detected in 193 patients on renal replacement therapy (52 transplant and 141 hemodialysis patients) and in 50 staff members of a Nephrology Department. Unequivocal seroconversion was documented in 5 transplant (9.6%) and in 26 dialysis patients (18.4%). In the dialysis population, the prevalence of anti-HCV antibodies was evaluated in patients grouped according to the number of blood transfusions and to the different sections of dialytic treatment. The most striking findings were the marked differences in the prevalence of anti-HCV antibodies among patients treated in different sections (from 0% to 70%), and the presence of a significant increase in alanine-amino-transferase (ALT) concentrations in 14 anti-HCV negative patients. The results suggest that the diffusion of non-A, non-B hepatitis is mainly transfusion-related, with the possibility of significant environmental diffusion related to the violation of infection-control measures. The current immunoassay is probably unable to detect the actual frequency of the infection.

The Chimpanzee Model of Viral Hepatitis: Advances in Understanding the Immune Response and Treatment of Viral Hepatitis

Chimpanzees (Pan troglodytes) have contributed to diverse fields of biomedical research due to their close genetic relationship to humans and in many instances due to the lack of any other animal model. This review focuses on the contributions of the chimpanzee model to research on hepatitis viruses where chimpanzees represented the only animal model (hepatitis B and C) or the most appropriate animal model (hepatitis A). Research with chimpanzees led to the development of vaccines for HAV and HBV that are used worldwide to protect hundreds of millions from these diseases and, where fully implemented, have provided immunity for entire generations. More recently, chimpanzee research was instrumental in the development of curative therapies for hepatitis C virus infections. Over a span of 40 years, this research would identify the causative agent of NonA,NonB hepatitis, validate the molecular tools for drug discovery, and provide safety and efficacy data on the therapies that now provide a rapid and complete cure of HCV chronic infections. Several cocktails of antivirals are FDA approved that eliminate the virus following 12 weeks of once-per-day oral therapy. This represents the first cure of a chronic viral disease and, once broadly implemented, will dramatically reduce the occurrence of cirrhosis and liver cancer. The recent contributions of chimpanzees to our current understanding of T cell immunity for HCV, development of novel therapeutics for HBV, and the biology of HAV are reviewed. Finally, a perspective is provided on the events leading to the cessation of the use of chimpanzees in research and the future of the chimpanzees previously used to bring about these amazing breakthroughs in human healthcare.

Impact of PNPLA3 and IFNL3 polymorphisms on hepatic steatosis in Asian patients with chronic hepatitis C

BACKGROUND AND AIMS

A recent meta-analysis revealed that the genotype PNPLA3 rs738409 GG is associated with a higher risk of hepatic steatosis (HS) in Caucasian patients with chronic hepatitis C (CHC). However, controversial results were found regarding Asian populations. Furthermore, previous studies have shown a negative association between interferon lambda 3 (IFNL3) rs12979860 CC and HS in Caucasian CHC patients, but there have been no reports indicating any such association in Asian populations. In this study, then, we investigated the association of PNPLA3 and IFNL3 polymorphisms with HS in Asian CHC patients.

METHODS

We enrolled consecutive CHC patients who underwent liver biopsy prior to antiviral therapy. We excluded those patients with decompensated liver disease, any co-existing chronic liver disease, or HIV or HBV co-infection.

RESULTS

1080 CHC patients were enrolled, and HS was found in 453 (41.9%) patients. The frequency distribution of the G allele was significantly associated with HS (P<0.001), and this conferred a higher risk to G allele homozygotes (OR: 2.06, 95% CI: 1.46-2.88, P <0.001) than to G allele carriers (OR: 1.98, 95% CI: 1.52-2.58, P<0.001). There was a borderline significant difference in the prevalence of HS in rs12979860 CC versus non-CC (40.8% versus 49.3%, P = 0.059). After adjustment for age, sex, body mass index, diabetes, and excessive alcohol intake, the rs738409 G allele homozygote carriers still carried a higher risk for HS (OR: 1.93, 95% CI: 1.35-2.77, P = 0.003).

CONCLUSION

The PNPLA3 rs738409 GG genotype is positively associated with HS, while the IFNL3 rs 12979860 CC genotype may be negatively associated with HS, in Asian CHC patients.

The association of elevated alanine aminotransferase levels with hepatitis E virus infections among blood donors in China

BACKGROUND

Transfusion transmission of hepatitis E virus (HEV) is an emerging health risk, yet blood donors are rarely screened for this pathogen. Many blood centers instituted screening of blood donors for elevated levels of alanine aminotransferase (ALT) levels to prevent hepatitis C virus, which has continued in China. We evaluated whether elevated ALT levels were associated with HEV among blood donors in China.

STUDY DESIGN AND METHODS

Blood samples were collected from 9069 qualified volunteer blood donors from four blood centers in China. A total of 5023 had elevated ALT levels, that is, more than 40 IU/L, and 4046 samples had normal ALT. We tested all the 9069 samples for anti-HEV immunoglobulin (Ig)M, anti-HEV IgG, and HEV antigen. Those who were positive for anti-HEV IgM or HEV antigen were tested individually for HEV RNA by polymerase chain reaction.

RESULTS

The prevalence of anti-HEV IgG in donors with elevated ALT levels (33.3%) was higher than those with normal ALT (24.9%; p < 0.01). The prevalence of anti-HEV IgM was similar in donations with increased ALT (1.41%) and normal ALT (1.46%). More ALT-elevated donations were HEV antigen positive, 62 of 5023 (1.23%), than were ALT-normal donations, seven of 4046 (0.17%; p < 0.01). Six donors with elevated ALT levels and acute HEV infection markers (anti-HEV IgM or HEV antigen) were HEV RNA positive.

CONCLUSION

Markers of active infection including HEV antigen and HEV RNA are significantly more common among donors with elevated ALT levels in China. These data support the fact that ALT testing of donors to HEV antigen or HEV RNA would have greater specificity and exclude fewer acceptable donors.

Viral Carcinogenesis

Cancer has been recognized for thousands of years. Egyptians believed that cancer occurred at the will of the gods. Hippocrates believed human disease resulted from an imbalance of the four humors: blood, phlegm, yellow bile, and black bile with cancer being caused by excess black bile. The lymph theory of cancer replaced the humoral theory and the blastema theory replaced the lymph theory. Rudolph Virchow was the first to recognize that cancer cells like all cells came from other cells and believed chronic irritation caused cancer. At the same time there was a belief that trauma caused cancer, though it never evolved after many experiments inducing trauma. The birth of virology occurred in 1892 when Dimitri Ivanofsky demonstrated that diseased tobacco plants remained infective after filtering their sap through a filter that trapped bacteria. Martinus Beijerinck would call the tiny infective agent a virus and both Dimitri Ivanofsky and Marinus Beijerinck would become the fathers of virology. Not to long thereafter, Payton Rous founded the field of tumor virology in 1911 with his discovery of a transmittable sarcoma of chickens by what would come to be called Rous sarcoma virus or RSV for short. The first identified human tumor virus was the Epstein-Barr virus (EBV), named after Tony Epstein and Yvonne Barr who visualized the virus particles in Burkitt's lymphoma cells by electron microscopy in 1965. Since that time, many viruses have been associated with carcinogenesis including the most studied, human papilloma virus associated with cervical carcinoma, many other anogenital carcinomas, and oropharyngeal carcinoma. The World Health Organization currently estimates that approximately 22% of worldwide cancers are attributable to infectious etiologies, of which viral etiologies is estimated at 15-20%. The field of tumor virology/viral carcinogenesis has not only identified viruses as etiologic agents of human cancers, but has also given molecular insights to all human cancers including the oncogene activation and tumor suppressor gene inactivation.

The history of hepatitis C virus (HCV): Basic research reveals unique features in phylogeny, evolution and the viral life cycle with new perspectives for epidemic control

The discovery of hepatitis C virus (HCV) in 1989 permitted basic research to unravel critical components of a complex life cycle for this important human pathogen. HCV is a highly divergent group of viruses classified in 7 major genotypes and a great number of subtypes, and circulating in infected individuals as a continuously evolving quasispecies destined to escape host immune responses and applied antivirals. Despite the inability to culture patient viruses directly in the laboratory, efforts to define the infectious genome of HCV resulted in development of experimental recombinant in vivo and in vitro systems, including replicons and infectious cultures in human hepatoma cell lines. And HCV has become a model virus defining new paradigms in virology, immunology and biology. For example, HCV research discovered that a virus could be completely dependent on microRNA for its replication since microRNA-122 is critical for the HCV life cycle. A number of other host molecules critical for HCV entry and replication have been identified. Thus, basic HCV research revealed important molecules for development of host targeting agents (HTA). The identification and characterization of HCV encoded proteins and their functional units contributed to the development of highly effective direct acting antivirals (DAA) against the NS3 protease, NS5A and the NS5B polymerase. In combination, these inhibitors have since 2014 permitted interferon-free therapy with cure rates above 90% among patients with chronic HCV infection; however, viral resistance represents a challenge. Worldwide control of HCV will most likely require the development of a prophylactic vaccine, and numerous candidates have been pursued. Research characterizing features critical for antibody-based virus neutralization and T cell based virus elimination from infected cells is essential for this effort. If the world community promotes an ambitious approach by applying current DAA broadly, continues to develop alternative viral- and host- targeted antivirals to combat resistant variants, and invests in the development of a vaccine, it would be possible to eradicate HCV. This would prevent about 500 thousand deaths annually. However, given the nature of HCV, the millions of new infections annually, a high chronicity rate, and with over 150 million individuals with chronic infection (which are frequently unidentified), this effort remains a major challenge for basic researchers, clinicians and communities.

Peromyscus as a model system for human hepatitis C: An opportunity to advance our understanding of a complex host parasite system

Worldwide, there are 185 million people infected with hepatitis C virus and approximately 350,000 people die each year from hepatitis C associated liver diseases. Human hepatitis C research has been hampered by the lack of an appropriate in vivo model system. Most of the in vivo research has been conducted on chimpanzees, which is complicated by ethical concerns, small sample sizes, high costs, and genetic heterogeneity. The house mouse system has led to greater understanding of a wide variety of human pathogens, but it is unreasonable to expect Mus musculus to be a good model system for every human pathogen. Alternative animal models can be developed in these cases. Ferrets (influenza), cotton rats (human respiratory virus), and woodchucks (hepatitis B) are all alternative models that have led to a greater understanding of human pathogens. Rodent models are tractable, genetically amenable and inbred and outbred strains can provide homogeneity in results. Recently, a rodent homolog of hepatitis C was discovered and isolated from the liver of a Peromyscus maniculatus. This represents the first small mammal (mouse) model system for human hepatitis C and it offers great potential to contribute to our understanding and ultimately aid in our efforts to combat this serious public health concern. Peromyscus are available commercially and can be used to inform questions about the origin, transmission, persistence, pathology, and rational treatment of hepatitis C. Here, we provide a disease ecologist's overview of this new virus and some suggestions for useful future experiments.

Improvement of renal dysfunction in a patient with hepatitis C virus-related liver cirrhosis by daclatasvir and asunaprevir combination therapy: A case report

Recently, treatments for chronic hepatitis C virus (HCV) infection have been drastically improved by the development of direct-acting antiviral agents. In September 2014, dual oral therapy using daclatasvir (DCV) and asunaprevir (ASV) was approved for the treatment of chronic HCV infection in Japan. We treated a patient with HCV-related liver cirrhosis with severe leg edema due to chronic renal dysfunction using this dual oral therapy. Although serum alanine aminotransferase increased rapidly during the first week of treatment, the antiviral therapy was able to continue, and liver function recovered spontaneously. After 1 month of treatment, serum HCV RNA became continuously undetectable, and serum albumin level gradually increased. Throughout the therapy, serum creatinine level nearly normalized, and leg edema gradually improved. These improvements continued after the combination therapy was completed. HCV RNA remained undetectable following the end of therapy, and sustained virological response at 12 weeks was achieved. It has been reported that chronic HCV infection is associated with renal dysfunction and that HCV eradication can improve it. DCV and ASV combination therapy is safe for patients who have renal dysfunction and may be a suitable therapy for chronic hepatitis C patients with renal dysfunction.

The Natural History of Hepatit is C Viral Infection: Clinical Evaluation and Monitoring

Hepatitis C virus (HCV) infection is one of the most common causes of chronic liver disease in the world and represents a substantial burden on global health systems and individual patient wellbeing. Routine screening for HCV in certain high-risk populations is appropriate. HCV can cause both an acute and chronic hepatitis, and manifests as a variety of hepatic and extrahepatic symptoms, largely influenced by a combination of host and viral factors. It can be difficult to predict clinical outcomes in individual cases. In those who suffer a chronic infection, progression to cirrhosis carries the risk of decompensation and hepatocellular carcinoma. The natural history of HCV infection and our understanding of risk factors that are predictive of disease progression are discussed.