Persistence of viremia and the importance of long-term follow-up after acute hepatitis C infection

To decline or not to decline: Consequences of decision-making regarding lung offers from donors with hepatitis C

OBJECTIVE

Lung transplants from donors with hepatitis C (HCV D+) have excellent outcomes, but these organs continue to be declined. We evaluated whether (1) being listed to consider and (2) accepting versus declining HCV D+ offers provided a survival benefit to lung transplant candidates.

METHODS

Using the Scientific Registry of Transplant Recipients, we identified all adult (≥18 years) lung transplant candidates 2016-2021 and compared waitlist mortality between those willing versus not willing to consider HCV D+ offers using competing risk regression. We identified all candidates offered an HCV D+ lung that was later accepted and followed them from offer decision until death or end-of-study. We estimated adjusted mortality risk of accepting versus declining an HCV D+ lung offer using propensity-weighted Cox regression.

RESULTS

From 2016 to 2021, we identified 21,007 lung transplant candidates, 33.8% of whom were willing to consider HCV D+ offers. Candidates willing to consider HCV D+ offers had a 17% lower risk of waitlist mortality (subhazard ratio, 0.83; 95% confidence interval, 0.75-0.91, P < .001). Over the same period, 665 HCV D+ lung offers were accepted after being declined a total of 2562 times. HCV D+ offer acceptance versus decline was associated with a 20% lower risk of mortality (adjusted hazard ratio, 0.80; 95% confidence interval, 0.66-0.96, P = .02).

CONCLUSIONS

Considering HCV D+ lung offers was associated with a 17% lower risk of waitlist mortality, whereas accepting versus declining an HCV D+ lung offer was associated with a 20% lower risk of mortality. Centers and candidates should consider accepting suitable HCV D+ lung offers to optimize outcomes.

Controlled Human Infection Model for Hepatitis C Virus Vaccine Development: Trial Design Considerations

The design of a clinical trial for a controlled human infection model (CHIM) to accelerate hepatitis C virus (HCV) vaccine development requires careful consideration. The design of a potential approach to HCV CHIM is outlined, involving initial sentinel cohorts to establish the safety and curability of the viral inoculum followed by larger cohorts to establish the spontaneous clearance rate for each inoculum. The primary endpoint would be HCV clearance by 24 weeks post-inoculation, recognizing that the prevention of chronic infection would be the primary goal of HCV vaccine candidates. Additional considerations are discussed, including the populations to be enrolled, the required monitoring approach, indications for antiviral therapy, and the required sample size for different CHIM approaches. Finally, safety considerations for CHIM participants are discussed.

The HCV Envelope Glycoprotein Down-Modulates NF-κB Signalling and Associates With Stimulation of the Host Endoplasmic Reticulum Stress Pathway

Following acute HCV infection, the virus establishes a chronic disease in the majority of patients whilst few individuals clear the infection spontaneously. The precise mechanisms that determine chronic HCV infection or spontaneous clearance are not completely understood but are proposed to be driven by host and viral genetic factors as well as HCV encoded immunomodulatory proteins. Using the HIV-1 LTR as a tool to measure NF-κB activity, we identified that the HCV E1E2 glycoproteins and more so the E2 protein down-modulates HIV-1 LTR activation in 293T, TZM-bl and the more physiologically relevant Huh7 liver derived cell line. We demonstrate this effect is specifically mediated through inhibiting NF-κB binding to the LTR and show that this effect was conserved for all HCV genotypes tested. Transcriptomic analysis of 293T cells expressing the HCV glycoproteins identified E1E2 mediated stimulation of the endoplasmic reticulum (ER) stress response pathway and upregulation of stress response genes such as ATF3. Through shRNA mediated inhibition of ATF3, one of the components, we observed that E1E2 mediated inhibitory effects on HIV-1 LTR activity was alleviated. Our in vitro studies demonstrate that HCV Env glycoprotein activates host ER Stress Pathways known to inhibit NF-κB activity. This has potential implications for understanding HCV induced immune activation as well as oncogenesis.

Different HCV Exposure Drives Specific miRNA Profile in PBMCs of HIV Patients

Micro RNAs (miRNAs) are essential players in HIV and HCV infections, as both viruses modulate cellular miRNAs and interact with the miRNA-mediated host response. We aim to analyze the miRNA profile of HIV patients with different exposure to HCV to explore specific signatures in the miRNA profile of PBMCs for each type of infection. We massively sequenced small RNAs of PBMCs from 117 HIV+ infected patients: 45 HIV+ patients chronically infected with HCV (HIV/HCV+), 36 HIV+ that spontaneously clarified HCV after acute infection (HIV/HCV-) and 36 HIV+ patients without previous HCV infection (HIV). Thirty-two healthy patients were used as healthy controls (HC). Differential expression analysis showed significantly differentially expressed (SDE) miRNAs in HIV/HCV+ (n = 153), HIV/HCV- (n = 169) and HIV (n = 153) patients. We found putative dysregulated pathways, such as infectious-related and PI3K signaling pathways, common in all contrasts. Specifically, putatively targeted genes involved in antifolate resistance (HIV/HV+), cancer-related pathways (HIV/HCV-) and HIF-signaling (HIV) were identified, among others. Our findings revealed that HCV strongly influences the expression profile of PBMCs from HIV patients through the disruption of its miRNome. Thus, different HCV exposure can be identified by specific miRNA signatures in PBMCs.

Seroprevalence of Hepatitis C in Children Without Identifiable Risk-Factors: A Systematic Review and Meta-Analysis

OBJECTIVES

Hepatitis C virus (HCV) remains a major public health burden for >30 years since its discovery. It is estimated that >80 million people have been already infected. Direct-acting antiviral (DAA) treatment is now approved for young children over the age of 3 years. Treating children before the development of high-risk behaviors is optimal. Thus, assessing the current epidemiology of HCV in children becomes important and may promote awareness.

METHODS

Articles describing the prevalence of hepatitis C in children, were systematically reviewed. To assess HCV infection prevalence in the general population, studies discussing high-risk groups alone were excluded.

RESULTS

Data from 58 studies were analyzed. National data was scarce. An overall prevalence of HCV in children of 0.87% was found, ranging from 0.34% in Europe to 3.02% in Africa. Prevalence of viremic infection is important and data synthesis from available data indicated that HCV viremia was detected in 56.8% of children. The prevalence of HCV according to sex was described in 25 studies but no difference between sexes was detected. HCV prevalence was significantly higher in children older than 10 years (0.97%) when compared to those ages under 10 years old (0.75%, P < 0.001).

CONCLUSIONS

Considering probable underdiagnosis of HCV infection in children, this information reveals that prevalence is substantial. One may argue that future strategies aiming towards HCV elimination, may need to include antiviral treatment of pre-adolescent children as well.

Hepatitis C-Positive Donors in Cardiac Transplantation: Problems and Opportunities

PURPOSE OF REVIEW

With the growing need for donor hearts and longer transplant waiting lists, there is a growing interest in expanding the donor pool by reconsidering previously excluded donor candidates. There has been an increase in solid organ availability due to drug overdose deaths in the setting of the recent opioid epidemic. However, these donors often have transmissible infections such as hepatitis C. In this review, we discuss the challenges associated with heart transplantation from hepatitis C-infected donors as well as the recent advancements that are making the use of these organs possible.

RECENT FINDINGS

With the introduction and widespread use of nucleic acid testing (NAT), the ability to distinguish viremic donors and those that have cleared the virus has become a reality. In addition, with the emergence of direct antiviral agents, there is an increase in data showing the short-term outcomes and success of hepatitis C treatment for recipients of viremic donor hearts. As techniques to distinguish donor hepatitis C infection status and successful treatments emerge, the percentage of accepted hepatitis C donor hearts is increasing. A number of studies showing success with hepatitis C organ transplants present a promising new avenue for organ procurement essential to meet the increasing demand for donor hearts.

Hepatitis C in 2020: A North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Position Paper

In 1989, a collaboration between the Centers for Disease Control (CDC) and a California biotechnology company identified the hepatitis C virus (HCV, formerly known as non-A, non-B hepatitis virus) as the causative agent in the epidemic of silent posttransfusion hepatitis resulting in cirrhosis. We now know that, the HCV genome is a 9.6 kb positive, single-stranded RNA. A single open reading frame encodes a 3011 amino acid residue polyprotein that undergoes proteolysis to yield 10 individual gene products, consisting of 3 structural proteins (core and envelope glycoproteins E1 and E2) and 7 nonstructural (NS) proteins (p7, NS2, NS3, NS4A, NS4B, NS5A, and NS5B), which participate in posttranslational proteolytic processing and replication of HCV genetic material. Less than 25 years later, a new class of medications, known as direct-acting antivirals (DAAs) which target these proteins, were introduced to treat HCV infection. These highly effective antiviral agents are now approved for use in children as young as 3 years of age and have demonstrated sustained virologic responses exceeding 90% in most genotypes. Although tremendous scientific progress has been made, the incidence of acute HCV infections has increased by 4-fold since 2005, compounded in the last decade by a surge in opioid and intravenous drug use. Unfortunately, awareness of this deadly hepatotropic virus among members of the lay public remains limited. Patient education, advocacy, and counseling must, therefore, complement the availability of curative treatments against HCV infection if this virus is to be eradicated.

Human Hepatitis B Viral Infection Outcomes Are Linked to Naturally Occurring Variants of HLA-DOA That Have Altered Function

HLA molecules of the MHC class II (MHCII) bind and present pathogen-derived peptides for CD4 T cell activation. Peptide loading of MHCII in the endosomes of cells is controlled by the interplay of the nonclassical MHCII molecules, HLA-DM (DM) and HLA-DO (DO). DM catalyzes peptide loading, whereas DO, an MHCII substrate mimic, prevents DM from interacting with MHCII, resulting in an altered MHCII-peptide repertoire and increased MHCII-CLIP. Although the two genes encoding DO (DOA and DOB) are considered nonpolymorphic, there are rare natural variants. Our previous work identified DOB variants that altered DO function. In this study, we show that natural variation in the DOA gene also impacts DO function. Using the 1000 Genomes Project database, we show that ∼98% of individuals express the canonical DOA*0101 allele, and the remaining individuals mostly express DOA*0102, which we found was a gain-of-function allele. Analysis of 25 natural occurring DOα variants, which included the common alleles, identified three null variants and one variant with reduced and nine with increased ability to modulate DM activity. Unexpectedly, several of the variants produced reduced DO protein levels yet efficiently inhibited DM activity. Finally, analysis of associated single-nucleotide polymorphisms genetically linked the DOA*0102 common allele, a gain-of-function variant, with human hepatitis B viral persistence. In contrast, we found that the DOα F114L null allele was linked with viral clearance. Collectively, these studies show that natural variation occurring in the human DOA gene impacts DO function and can be linked to specific outcomes of viral infections.

Testing and Clinical Management of Health Care Personnel Potentially Exposed to Hepatitis C Virus - CDC Guidance, United States, 2020

Exposure to hepatitis viruses is a recognized occupational risk for health care personnel (HCP). This report establishes new CDC guidance that includes recommendations for a testing algorithm and clinical management for HCP with potential occupational exposure to hepatitis C virus (HCV). Baseline testing of the source patient and HCP should be performed as soon as possible (preferably within 48 hours) after the exposure. A source patient refers to any person receiving health care services whose blood or other potentially infectious material is the source of the HCP's exposure. Two options are recommended for testing the source patient. The first option is to test the source patient with a nucleic acid test (NAT) for HCV RNA. This option is preferred, particularly if the source patient is known or suspected to have recent behaviors that increase risk for HCV acquisition (e.g., injection drug use within the previous 4 months) or if risk cannot be reliably assessed. The second option is to test the source patient for antibodies to hepatitis C virus (anti-HCV), then if positive, test for HCV RNA. For HCP, baseline testing for anti-HCV with reflex to a NAT for HCV RNA if positive should be conducted as soon as possible (preferably within 48 hours) after the exposure and may be simultaneous with source-patient testing. If follow-up testing is recommended based on the source patient's status (e.g., HCV RNA positive or anti-HCV positive with unavailable HCV RNA or if the HCV infection status is unknown), HCP should be tested with a NAT for HCV RNA at 3-6 weeks postexposure. If HCV RNA is negative at 3-6 weeks postexposure, a final test for anti-HCV at 4-6 months postexposure is recommended. A source patient or HCP found to be positive for HCV RNA should be referred to care. Postexposure prophylaxis of hepatitis C is not recommended for HCP who have occupational exposure to blood and other body fluids. This guidance was developed based on expert opinion (CDC. Updated U.S. Public Health Service guidelines for the management of occupational exposures to HBV, HCV, and HIV and recommendations for postexposure prophylaxis. MMWR Recommend Rep 2001;50[No. RR-11]; Supplementary Figure, https://stacks.cdc.gov/view/cdc/90288) and reflects updated guidance from professional organizations that recommend treatment for acute HCV infection. Health care providers can use this guidance to update their procedures for postexposure testing and clinical management of HCP potentially exposed to hepatitis C virus.

Usage of HCV viremic organs in liver transplantation to anti-HCV negative recipients: The current status and review of literature

Liver transplantation is the main curative therapy for end-stage liver disease. The number of transplanted organs is increasing globally. However, the number of available organs in the pool is insufficient, considering the excessive number of patients on the waiting list, which is a major concern for transplant programs. Hepatitis C infection (HCV) is a common indication for liver transplantation, and in recent years, a major progress has been made in its treatment with direct-acting antiviral (DAA) agents. HCV-positive livers have been transplanted to HCV-positive recipients for a long time. The high rate of sustained virologic response through DAA has brought new treatment options for the patients during the pre- and post-transplantation periods. Recently, there have been few reports of transplanting the available HCV-positive organs to HCV noninfected recipients. However, there is not yet an agreement on the optimal selection of patients who would benefit from such transplantation, and this has become a current topic of interest. Thus, we aim to review the current literature on this evolving topic.

Injection drug network characteristics as a predictor of injection behaviour

Social network characteristics of people who inject drugs (PWID) have previously been flagged as potential risk factors for HCV transmission such as increased injection frequency. To understand the role of the injecting network on injection frequency, we investigated how changes in an injecting network over time can modulate injecting risk behaviour. PWID were sourced from the Networks 2 Study, a longitudinal cohort study of PWID recruited from illicit drug street markets across Melbourne, Australia. Network-related correlates of injection frequency and the change in frequency over time were analysed using adjusted Cox Proportional Hazards and Generalised Estimating Equations modelling. Two-hundred and eighteen PWID followed up for a mean (s.d.) of 2.8 (1.7) years were included in the analysis. A greater number of injecting partners, network closeness centrality and eigenvector centrality over time were associated with an increased rate of infection frequency. Every additional injection drug partner was associated with an increase in monthly injection frequency. Similarly, increased network connectivity and centrality over time was also associated with an increase in injection frequency. This study observed that baseline network measures of connectivity and centrality may be associated with changes in injection frequency and, by extension, may predict subsequent HCV transmission risk. Longitudinal changes in network position were observed to correlate with changes in injection frequency, with PWID who migrate from the densely-connected network centre out to the less-connected periphery were associated with a decreased rate of injection frequency.

Rheumatologic manifestations of hepatitis C in the era of direct-acting antiviral agents

Beyond the classic hepatic complications, hepatitis C (HCV) infection is considered as a systemic disease, since extrahepatic manifestations become clinically evident in 40% to 70% of the patients and it can frequently include rheumatic ones. Furthermore, HCV can promote the production of several autoantibodies, thus complicating the differential diagnosis between primitive and HCV-related rheumatic disorders. The recent development of direct-acting antivirals (DAA) against HCV has revolutionized the field, reducing the damage stemming from systemic inflammatory phenomena and persistent immune activation associated with continuous HCV replication. Our review focuses on the main rheumatologic manifestations associated with chronic HCV infection as well as the impact of DAA interferon-free treatments on such extrahepatic clinical involvement.

Hepatitis C Virus Prevalence in 50 U.S. States and D.C. by Sex, Birth Cohort, and Race: 2013-2016

Hepatitis C virus (HCV) infection is a leading cause of liver-related morbidity and mortality, and more than 2 million adults in the United States are estimated to be currently infected. Reducing HCV burden will require an understanding of demographic disparities and targeted efforts to reduce prevalence in populations with disproportionate disease rates. We modeled state-level estimates of hepatitis C prevalence among U.S. adults by sex, birth cohort, and race during 2013-2016. National Health and Nutrition Examination Survey data were used in combination with state-level HCV-related and narcotic overdose-related mortality data from the National Vital Statistics System and estimates from external literature review on populations not sampled in the National Health and Nutrition Examination Survey. Nationally, estimated hepatitis C prevalence was 1.3% among males and 0.6% among females (prevalence ratio [PR] = 2.3). Among persons born during 1945 to 1969, prevalence was 1.6% compared with 0.5% among persons born after 1969 (PR = 3.2). Among persons born during 1945 to 1969, prevalence ranged from 0.7% in North Dakota to 3.6% in Oklahoma and 6.8% in the District of Columbia. Among persons born after 1969, prevalence was more than twice as high in Kentucky, New Mexico, Oklahoma, and West Virginia compared with the national average. Hepatitis C prevalence was 1.8% among non-Hispanic black persons and 0.8% among persons of other races (PR = 2.2), and the magnitude of this disparity varied widely across jurisdictions (PR range: 1.3-7.8). Overall, 23% of prevalent HCV infections occurred among non-Hispanic black persons, whereas 12% of the population was represented by this racial group. These estimates provide information on prevalent HCV infections that jurisdictions can use for understanding and monitoring local disease patterns and racial disparities in burden of disease.

Genetic Polymorphisms within Interferon-λ Region and Interferon-λ3 in the Human Pathophysiology: Their Contribution to Outcome, Treatment, and Prevention of Infections with Hepatotropic Viruses

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Genetic polymorphisms within the interferon λ (IFN-λ) chromosomal region, mainly rs12979860 of IFN-λ4 gene (IFNL4), are known as associated with spontaneous hepatitis C virus (HCV) resolution and sustained viral response to therapy with pegylated interferon- α and ribavirin. Strong linkage disequilibrium of IFNL4 rs12979860 with IFNL4 rs368234815, which is casually associated with HCV spontaneous and therapeutical eradication, at least partially explains favorable HCV outcomes attributed to major homozygosity in rs12979860. Effects of IFN-based antiviral treatment are associated with pretreatment expression of the IFN-λ1 receptor, expression of hepatic IFN-stimulated genes, production of IFN- λ4, and preactivation of the JAK-STAT signaling. Nowadays direct-acting antivirals (DAAs) became a potent tool in the treatment of hepatitis C, but IFN-λs are still under investigation as potential antivirals and might be an option in HCV infection (DAA resistance, recurrent viremia, adverse effects).

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Patients with altered immunocompetence are especially prone to infections. In uremic subjects, polymorphisms within the IFN-λ chromosomal region associate with spontaneous HCV clearance, similarly like in the non-uremic population. Circulating IFN-λ3 shows a positive correlation with plasma titers of antibodies to surface antigen of hepatitis B virus (anti-HBs), which are crucial for protection against hepatitis B virus. More efficient anti-HBs production in the presence of higher IFN-λ3 levels might occur due to IFN-λ3-induced regulation of indoleamine 2,3-dioxygenase (IDO) expression. IFN-stimulated response element is a part of IDO gene promoter. It is worth further investigation whether IDO gene, circulating IDO, genetic polymorphisms within the IFN-λ region, and circulating IFN-λ3 act in concordance in immunological response to hepatotropic viruses.

Hepatic late adverse effects after antineoplastic treatment for childhood cancer

BACKGROUND

Survival rates have greatly improved as a result of more effective treatments for childhood cancer. Unfortunately, the improved prognosis has been accompanied by the occurrence of late, treatment-related complications. Liver complications are common during and soon after treatment for childhood cancer. However, among long-term childhood cancer survivors, the risk of hepatic late adverse effects is largely unknown. To make informed decisions about future cancer treatment and follow-up policies, it is important to know the risk of, and associated risk factors for, hepatic late adverse effects. This review is an update of a previously published Cochrane review.

OBJECTIVES

To evaluate all the existing evidence on the association between antineoplastic treatment (that is, chemotherapy, radiotherapy involving the liver, surgery involving the liver and BMT) for childhood cancer and hepatic late adverse effects.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2018, Issue 1), MEDLINE (1966 to January 2018) and Embase (1980 to January 2018). In addition, we searched reference lists of relevant articles and scanned the conference proceedings of the International Society of Paediatric Oncology (SIOP) (from 2005 to 2017) and American Society of Pediatric Hematology/Oncology (ASPHO) (from 2013 to 2018) electronically.

SELECTION CRITERIA

All studies, except case reports, case series, and studies including fewer than 10 patients that examined the association between antineoplastic treatment for childhood cancer (aged 18 years or less at diagnosis) and hepatic late adverse effects (one year or more after the end of treatment).

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection and 'risk of bias' assessment. The 'risk of bias' assessment was based on earlier checklists for observational studies. For the original version of the review, two review authors independently performed data extraction. For the update of the review, the data extraction was performed by one reviewer and checked by another reviewer.

MAIN RESULTS

Thirteen new studies were identified for the update of this review. In total, we included 33 cohort studies including 7876 participants investigating hepatic late adverse effects after antineoplastic treatment (especially chemotherapy and radiotherapy) for different types of childhood cancer, both haematological and solid malignancies. All studies had methodological limitations. The prevalence of hepatic late adverse effects, all defined in a biochemical way, varied widely, between 0% and 84.2%. Selecting studies where the outcome of hepatic late adverse effects was well-defined as alanine aminotransferase (ALT) above the upper limit of normal, indicating cellular liver injury, resulted in eight studies. In this subgroup, the prevalence of hepatic late adverse effects ranged from 5.8% to 52.8%, with median follow-up durations varying from three to 23 years since cancer diagnosis in studies that reported the median follow-up duration. A more stringent selection process using the outcome definition of ALT as above twice the upper limit of normal, resulted in five studies, with a prevalence ranging from 0.9% to 44.8%. One study investigated biliary tract injury, defined as gamma-glutamyltransferase (γGT) above the upper limit of normal and above twice the upper limit of normal and reported a prevalence of 5.3% and 0.9%, respectively. Three studies investigated disturbance in biliary function, defined as bilirubin above the upper limit of normal and reported prevalences ranging from 0% to 8.7%. Two studies showed that treatment with radiotherapy involving the liver (especially after a high percentage of the liver irradiated), higher BMI, and longer follow-up time or older age at evaluation increased the risk of cellular liver injury in multivariable analyses. In addition, there was some suggestion that busulfan, thioguanine, hepatic surgery, chronic viral hepatitis C, metabolic syndrome, use of statins, non-Hispanic white ethnicity, and higher alcohol intake (> 14 units per week) increase the risk of cellular liver injury in multivariable analyses. Chronic viral hepatitis was shown to increase the risk of cellular liver injury in six univariable analyses as well. Moreover, one study showed that treatment with radiotherapy involving the liver, higher BMI, higher alcohol intake (> 14 units per week), longer follow-up time, and older age at cancer diagnosis increased the risk of biliary tract injury in a multivariable analysis.

AUTHORS' CONCLUSIONS

The prevalence of hepatic late adverse effects among studies with an adequate outcome definition varied considerably from 1% to 53%. Evidence suggests that radiotherapy involving the liver, higher BMI, chronic viral hepatitis and longer follow-up time or older age at follow-up increase the risk of hepatic late adverse effects. In addition, there may be a suggestion that busulfan, thioguanine, hepatic surgery, higher alcohol intake (>14 units per week), metabolic syndrome, use of statins, non-Hispanic white ethnicity, and older age at cancer diagnosis increase the risk of hepatic late adverse effects. High-quality studies are needed to evaluate the effects of different therapy doses, time trends, and associated risk factors after antineoplastic treatment for childhood cancer.

Multi-Ancestry Genome-Wide Association Study of Spontaneous Clearance of Hepatitis C Virus

BACKGROUND & AIMS

Spontaneous clearance of hepatitis C virus (HCV) occurs in approximately 30% of infected persons and less often in populations of African ancestry. Variants in major histocompatibility complex (MHC) and in interferon lambda genes are associated with spontaneous HCV clearance, but there have been few studies of these variants in persons of African ancestry. We performed a dense multi-ancestry genome-wide association study of spontaneous clearance of HCV, focusing on individuals of African ancestry.

METHODS

We performed genotype analyses of 4423 people from 3 ancestry groups: 2201 persons of African ancestry (445 with HCV clearance and 1756 with HCV persistence), 1739 persons of European ancestry (701 with HCV clearance and 1036 with HCV persistence), and 486 multi-ancestry Hispanic persons (173 with HCV clearance and 313 with HCV persistence). Samples were genotyped using Illumina (San Diego, CA) arrays and statistically imputed to the 1000 Genomes Project. For each ancestry group, the association of single-nucleotide polymorphisms with HCV clearance was tested by log-additive analysis, and then a meta-analysis was performed.

RESULTS

In the meta-analysis, significant associations with HCV clearance were confirmed at the interferon lambda gene locus IFNL4-IFNL3 (19q13.2) (P = 5.99 × 10-50) and the MHC locus 6p21.32 (P = 1.15 × 10-21). We also associated HCV clearance with polymorphisms in the G-protein-coupled receptor 158 gene (GPR158) at 10p12.1 (P = 1.80 × 10-07). These 3 loci had independent, additive effects of HCV clearance, and account for 6.8% and 5.9% of the variance of HCV clearance in persons of European and African ancestry, respectively. Persons of African or European ancestry carrying all 6 variants were 24-fold and 11-fold, respectively, more likely to clear HCV infection compared with individuals carrying none or 1 of the clearance-associated variants.

CONCLUSIONS

In a meta-analysis of data from 3 studies, we found variants in MHC genes, IFNL4-IFNL3, and GPR158 to increase odds of HCV clearance in patients of European and African ancestry. These findings could increase our understanding of immune response to and clearance of HCV infection.

Inconsistent temporal patterns of genetic variation of HCV among high-risk subjects may impact inference of transmission networks

Hepatitis-C Virus (HCV) sequences are often used to establish networks of people who inject drugs (PWID). However, the degree to which within-host evolutionary dynamics affect those inferences has not been carefully studied. Here, we analyzed 702 longitudinally-sampled HCV E1 sequences from 88 HCV+ people who inject drugs (PWID) in the Baltimore Before and After Acute Study of Hepatitis (BBAASH) cohort. Individuals were tested for HCV RNA over multiple visits to the clinic, and the HCV E1 gene was sequenced for HCV+ samples. Genetic clustering was performed on the full set of sequences using a 3% genetic distance threshold to define epidemiological linkage. Maximum-likelihood (ML) phylogenies were inferred to assess evolutionary relationships. We found 22 clusters containing sequences sampled over five or more years (long-term clusters, LTC), of which 17 had >1 subject. In six of the multi-subject LTC, one subject had a sequence sampled >3 years earlier or later than the next-closest subject in the cluster (time-gap LTC). ML trees showed that, in three of the time-gap LTC, two subjects had identical sequences despite 7-10 years separating the sampling times. In four of the time-gap LTC for whom additional data were available, the subject with the later detected shared variant had both different variants and visits with no detectable HCV RNA (RNA-) prior to the appearance of the shared variant. In the subject with the earlier detection of the shared variant, different variants and RNA- visits were also detected in multiple cases subsequent to appearance of the shared variant. Complex patterns of shared viral variation among PWID reflect on-going re-infection, multiple transmission partners, and/or inconsistent detection of viral variants. Our results suggest that transmission events are currently underestimated by analysis of sequences at a single point in time.

Trends in methamphetamine and opioid use among clients of needle-syringe programs in Queensland, Australia: 2007-2015

INTRODUCTION AND AIMS

Needle-syringe programs (NSP) are an underutilized source of data on drug injection trends; these data are essential for informing public health interventions. We examine trends in NSP service occasions from 2007-2015.

DESIGN AND METHODS

Using standardised data from 26 NSP outlets through the Queensland NSP Minimum Data Set (QNSPMDS), trends in service occasions among clients intending to inject methamphetamine, heroin, opioid substitution therapy (OST) medications and other pharmaceutical opioids were assessed using multilevel mixed-effects negative binomial regression, adjusting for month, year, age and clustering by site.

RESULTS

Over 1.5 million service occasions were recorded in 2007-2015. Methamphetamine was the main 'drug intended to inject' (33.7%), however cf. 2007, the incidence rate ratio decreased to 0.64 (95% CI: 0.62, 0.66) in 2009, remaining low until 2015. Among clients reporting methamphetamine injection, there was a shift in the form from base to the higher-potency crystal methamphetamine since 2012. Heroin injection (22.5% service occasions) initially increased (cf. 2007), followed by a decline to 0.77 (95% CI: 0.75, 0.79) in 2015. Significant and sustained increases in OST and other pharmaceutical opioids injection were observed throughout the study period, accounting for 7.2% and 19.8% of total visits, respectively.

DISCUSSION AND CONCLUSIONS

The QNSPMDS provides unique, routinely collected, jurisdiction-wide and standardised data on the demographics of people who inject drugs, types of drugs injected and regional variations; these data are essential in informing policy, planning and program implementation. There remains significant opportunity to enhance engagement and linkage to care alongside needle-syringe provision.

Validation of Multiplex Serology for human hepatitis viruses B and C, human T-lymphotropic virus 1 and Toxoplasma gondii

Multiplex Serology is a high-throughput technology developed to simultaneously measure specific serum antibodies against multiple pathogens in one reaction vessel. Serological assays for hepatitis B (HBV) and C (HCV) viruses, human T-lymphotropic virus 1 (HTLV-1) and the protozoan parasite Toxoplasma gondii (T. gondii) were developed and validated against established reference assays. For each pathogen, between 3 and 5 specific antigens were recombinantly expressed as GST-tag fusion proteins in Escherichia coli and tested in Monoplex Serology, i.e. assays restricted to the antigens from one particular pathogen. For each of the four pathogen-specific Monoplex assays, overall seropositivity was defined using two pathogen-specific antigens. In the case of HBV Monoplex Serology, the detection of past natural HBV infection was validated based on two independent reference panels resulting in sensitivities of 92.3% and 93.0%, and specificities of 100% in both panels. Validation of HCV and HTLV-1 Monoplex Serology resulted in sensitivities of 98.0% and 95.0%, and specificities of 96.2% and 100.0%, respectively. The Monoplex Serology assay for T. gondii was validated with a sensitivity of 91.2% and specificity of 92.0%. The developed Monoplex Serology assays largely retained their characteristics when they were included in a multiplex panel (i.e. Multiplex Serology), containing additional antigens from a broad range of other pathogens. Thus HBV, HCV, HTLV-1 and T. gondii Monoplex Serology assays can efficiently be incorporated into Multiplex Serology panels tailored for application in seroepidemiological studies.

The Multifaceted Roles of Autophagy in Flavivirus-Host Interactions

Autophagy is an evolutionarily conserved cellular process in which intracellular components are eliminated via lysosomal degradation to supply nutrients for organelle biogenesis and metabolic homeostasis. Flavivirus infections underlie multiple human diseases and thus exert an immense burden on public health worldwide. Mounting evidence indicates that host autophagy is subverted to modulate the life cycles of flaviviruses, such as hepatitis C virus, dengue virus, Japanese encephalitis virus, West Nile virus and Zika virus. The diverse interplay between autophagy and flavivirus infection not only regulates viral growth in host cells but also counteracts host stress responses induced by viral infection. In this review, we summarize the current knowledge on the role of autophagy in the flavivirus life cycle. We also discuss the impacts of virus-induced autophagy on the pathogeneses of flavivirus-associated diseases and the potential use of autophagy as a therapeutic target for curing flavivirus infections and related human diseases.

Correlation of IL28B rs12979860 genotype and gender with spontaneous clearance of HCV infection: a Pakistani cross-section study

AIM

There is a strong correlation of IL28B rs12979860 genetic variations and gender with spontaneous clearance of hepatitis C virus (HCV) infection.

MATERIALS & METHODS

HCV-infected subjects were categorized into HCV spontaneous clearance (SC) group and chronic hepatitis C (CHC) group on the basis of anti-HCV antibodies and HCV RNA level and follow-up of 6 months. 35 subjects were classified in SC group and 165 subjects were classified in CHC group. IL28B rs12979860 genotypes were determined by allele-specific PCR.

RESULTS & CONCLUSION

Multinominal logistic regression analyses revealed that both genders favor IL28B rs12979860 CT genotype (OR: 4.80; CI: 2.22-10.35; p = 0.0005) and (OR: 3.47; CI: 1.63-7.43; p = 0.001) for male and female, respectively, are significant in spontaneous clearance of HCV infection.

Management of acute HCV infection in the era of direct-acting antiviral therapy

The management of acute HCV infection has not been standardized following the availability of direct-acting antiviral agents (DAAs) for chronic HCV infection, and substantial uncertainty exists regarding the optimal treatment regimen and duration. Despite the lack of direct evidence, the 2016 American Association for the Study of Liver Diseases (AASLD)-Infectious Diseases Society of America (IDSA) guidelines supported "the same regimens for acute HCV as recommended for chronic HCV infection … owing to high efficacy and safety", whereas the 2016 European Association for the Study of the Liver (EASL) guidelines recommended sofosbuvir-ledipasvir, sofosbuvir-velpatasvir or sofosbuvir plus daclatasvir for 8 weeks in acute HCV infection, with a longer duration of 12 weeks recommended for those infected with HIV and/or baseline HCV RNA levels >1,000,000 IU/ml. This Review outlines the epidemiology, natural history and diagnosis of acute HCV infection and provides contemporary information on DAAs for acute and recent HCV infection. The Review also discusses the 2016 AASLD-IDSA and EASL recommendations for acute HCV infection management in light of available evidence and highlights key differences in study populations and design that influence interpretation. We focus on populations at high risk of HCV transmission and acquisition, including people who inject drugs and HIV-positive men who have sex with men, and highlight the potential effects of diagnosis and treatment of acute HCV infection in contributing to HCV elimination.

Should organs from hepatitis C-positive donors be used in hepatitis C-negative recipients for liver transplantation?

Given the scarcity of donated organs and the frequency of death on the waiting list, strategies that could improve the available supply of high-quality liver grafts are much needed. Direct-acting antiviral agent (DAA) regimens have proved to be highly effective to treat hepatitis C virus (HCV), even in the setting of posttransplantation. The question arises as to whether transplant communities should consider the utilization of HCV-positive donors into HCV-negative recipients. This review summarizes risk of transmission, treatment options with success rate, and ethical considerations for usage of HCV-positive donors. Liver Transplantation 24 831-840 2018 AASLD.

Estimates of state-level chronic hepatitis C virus infection, stratified by race and sex, United States, 2010

Background

Hepatitis C virus (HCV) is the most common blood-borne viral infection in the United States. Previously, we used data from the National Health and Nutrition Examination Survey (NHANES) and mortality data from the National Vital Statistics System (NVSS) to estimate the prevalence of HCV antibodies (anti-HCV) and HCV RNA among all U.S. states. However, demographic differences in HCV burden at the state-level have not been systematically described. This analysis quantified the HCV burden stratified by sex and race (and associated disparities) for each U.S. state.

Methods

Building on our previous method, we used three publicly available data sources to estimate HCV RNA prevalence among noninstitutionalized adults stratified by sex and race group. We used a small-area estimation approach that included direct standardization of NHANES demographic data with logistic regression modeling of HCV-related mortality data as an adjustment factor to estimate the state-level prevalence and total persons with chronic HCV infection for sex and race groups in all U.S. states.

Results

Nationally, males had an estimated HCV RNA prevalence of 1.56% (95% CI: 1.37–1.84%) and females had a prevalence of 0.75% (95% CI: 0.63–0.96%). Stratified by race, national estimated prevalence of HCV RNA was highest among non-Hispanic black (2.43, 95% CI: 2.10–2.90%), followed by non-Hispanic white (1.05, 95% CI: 0.90–1.27%) and Hispanic/other (0.74, 95% CI: 0.59–1.04%). Males in most jurisdictions (41/51) have an HCV RNA prevalence that is between 1.5 and 2.5 times higher than their female counterparts.

Conclusions

HCV infection disparities by sex are mostly consistent across the country. However, race differences in HCV infection differ by state and tailored prevention and treatment efforts specific to the local HCV epidemic are needed to reduce race disparities.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3133-6) contains supplementary material, which is available to authorized users.

Hepatitis C transmission from seropositive, nonviremic donors to non-hepatitis C liver transplant recipients

Breakthroughs in hepatitis C virus (HCV) treatment and rising rates of intravenous drug use have led to an increase in the number of organ donors who are HCV antibody-positive but serum nucleic acid test (NAT)-negative. The risk of HCV transmission from the liver grafts of these donors to recipients is unknown. To estimate the incidence of HCV transmission, we prospectively followed 26 consecutive HCV antibody-negative (n = 25) or NAT-negative (n = 1) transplant recipients who received a liver graft from donors who were HCV antibody-positive but serum NAT-negative between March 2016 and March 2017. HCV transmission was considered to have occurred if recipients exhibited a positive HCV PCR test by 3 months following transplantation. Drug overdose was listed as the cause of death in 15 (60%) of the donors. One recipient died 18 days after transplantation from primary graft nonfunction and was excluded. Of the remaining 25 recipients, HCV transmission occurred in 4 (16%), at a median follow-up of 11 months, all from donors who died of drug overdose. Three of these patients were treated with direct-acting antiviral therapy, with two achieving a sustained virologic response and one an end-of-treatment response. One patient with HCV transmission died after a complicated postoperative course and did not receive antiviral therapy.

CONCLUSION

In this prospective cohort of non-HCV liver recipients receiving grafts from HCV antibody-positive/NAT-negative donors, the incidence of HCV transmission was 16%, with the highest risk conferred by donors who died of drug overdose; given the availability of safe and highly effective antiviral therapies, use of such organs could be considered to expand the donor pool. (Hepatology 2018;67:1673-1682).

Protease inhibitor therapy for hepatitis C virus-infection

INTRODUCTION

The hepatitis C virus (HCV) has affected an estimated of 80 million individuals worldwide and is a strain on public health. Around 25-30% of patients in Europe and the US who are infected with HIV are coinfected with HCV. Prior to 2013, treatment modalities containing an NS3/4A protease inhibitor in combination with pegylated interferon and ribavirin improved sustained virological response (SVR) rates. However, rates of severe side effects were high. Nowadays, oral direct-acting antiviral (DAA) combination therapy offers excellent treatment efficacy, safety and tolerability.

AREAS COVERED

This review focuses on the current literature and clinical evidence and their impact regarding NS3/4A protease inhibitors. The pitfalls encountered in treating HIV- and HBV-coinfected patients are also discussed.

EXPERT OPINION

In the era of DAA treatment, third-generation pan-genotypic NS3/4A protease inhibitors (mainly glecaprevir and voxilaprevir) show high antiviral activity and a genetic resistance barrier with cure rates of over 95% when combined with an NS5A inhibitor, irrespective of baseline resistance associated variants (RASs) being present. These new key components of DAA combination therapy are impressive options to eradicate HCV in the so-called difficult-to-treat population (e.g. compensated cirrhosis, end-stage renal disease and patients who failed previous DAA treatment).

A Biomolecular Network Driven Proteinic Interaction in HCV Clearance

Hepatitis C virus infection causes chronic liver disease that leads to cancer-related mortality. Presently around 30% of the HCV (infected) affected population get rid of the infection through spontaneous disease clearance. This phenomenon is conducted by a set of reported immune candidate genes. Hence, this study focuses only on these immune-response related genes with aid of network approach, where the idea is to disseminate the network for better understanding of key functional genes and their transcription control activity. Based on the network analysis the IFNG, TNF, IFNB1, STAT1, NFKB1, STAT3, SOCS1, and MYD88 genes are prioritized as hub genes along with their common transcription factors (TFs), IRF9, NFKB1, and STAT1. The dinucleotide frequency of TF binding elements indicated GG-rich motifs in these regulatory elements. On the other hand, gene enrichment report suggests the regulation of response to interferon gamma signaling pathway, which plays central role in the spontaneous HCV clearance. Therefore, our study tends to prioritize the genes, TFs, and their regulatory pathway towards HCV clearance. Even so, the resultant hub genes and their TFs and TF binding elements could be crucial in underscoring the clearance activity in specific populations.

Utilization of Organs From Donors According to Hepatitis C Antibody and Nucleic Acid Testing Status: Time for Change

Previous studies have grouped all donors positive for hepatitis C virus (HCV) antibody (Ab). Only recently has donor HCV nucleic acid testing (NAT) become routine, and the impact of Ab and NAT status on organ utilization is unknown. Using the United Network for Organ Sharing database, we identified 9290 donors from 2015 to 2016 for whom both HCV Ab and NAT data were available and compared organ utilization by HCV status. Overall, 93.8% of donors were Ab negative and NAT negative (Ab-NAT-), 0.15% were Ab negative and NAT positive, 1.8% were Ab positive and NAT negative (Ab+NAT-), and 4.2% were both Ab and NAT positive (Ab+NAT+). Ab-NAT- donors donated at the highest rate for all organs except livers, of which Ab+NAT- donors donated at a higher rate (81.2% vs 73.2%, p = 0.03). Livers were discarded for reasons related to abnormal biopsies in Ab+NAT+ donors, whereas kidneys from Ab- or NAT-positive donors were discarded for reasons related to HCV status. Using a propensity score-matched model, we estimated that using Ab+NAT- donors at the same rate as Ab-NAT- donors could result in 48 more kidney donors, 37 more heart donors, and 15 more lung donors annually. We urge the use of HCV Ab+NAT- donors for appropriately selected and consenting recipients.

Neutralizing Antibody Responses to Viral Infections Are Linked to the Non-classical MHC Class II Gene H2-Ob

Select humans and animals control persistent viral infections via adaptive immune responses that include production of neutralizing antibodies. The precise genetic basis for the control remains enigmatic. Here, we report positional cloning of the gene responsible for production of retrovirus-neutralizing antibodies in mice of the I/LnJ strain. It encodes the beta subunit of the non-classical major histocompatibility complex class II (MHC-II)-like molecule H2-O, a negative regulator of antigen presentation. The recessive and functionally null I/LnJ H2-Ob allele supported the production of virus-neutralizing antibodies independently of the classical MHC haplotype. Subsequent bioinformatics and functional analyses of the human H2-Ob homolog, HLA-DOB, revealed both loss- and gain-of-function alleles, which could affect the ability of their carriers to control infections with human hepatitis B (HBV) and C (HCV) viruses. Thus, understanding of the previously unappreciated role of H2-O (HLA-DO) in immunity to infections may suggest new approaches in achieving neutralizing immunity to viruses.

Chronic hepatitis C virus infection and neurocognitive function in adult survivors of childhood cancer

BACKGROUND

Cancer survivors transfused with blood products before reliable screening for hepatitis C virus (HCV) are at risk for infection. This study examined the impact of HCV on neurocognitive function and health-related quality of life (HRQOL) among adult survivors of childhood cancer.

METHODS

Neurocognitive testing was conducted for 836 adult survivors of childhood cancer (mean age, 35 years [standard deviation, 7.4 years]; time since diagnosis, 29 years [standard deviation, 6.2 years]) who received blood products before universal HCV screening. No differences were observed between confirmed HCV-seropositive survivors (n = 79) and HCV-seronegative survivors (n = 757) in the primary diagnosis or neurotoxic therapies. Multivariate regression models were used to compare functional outcomes between seropositive and seronegative survivors.

RESULTS

Compared with seronegative survivors, seropositive survivors demonstrated lower performance on measures of attention (P < .001), processing speed (P = .008), long-term verbal memory (P = .01), and executive function (P = .001). After adjustments for sex, age at diagnosis, and treatment exposures, seropositive survivors had a higher prevalence of impairment in processing speed (prevalence ratio [PR], 1.3; 95% confidence interval [CI], 1.1-1.6) and executive functioning (PR, 1.3; 95% CI, 1.1-1.6). Differences were not associated with the treatment of HCV or the presence of liver cirrhosis. Seropositive survivors reported worse general HRQOL (PR, 1.6; 95% CI, 1.2-2.1), which was associated with the presence of liver cirrhosis (P = .001).

CONCLUSIONS

Survivors of childhood cancer with a history of HCV infection are at risk for neurocognitive impairment and reduced HRQOL beyond the known risks associated with neurotoxic cancer therapies. Cancer 2017;123:4498-505. © 2017 American Cancer Society.

Quinolinate Phosphoribosyltransferase is an Antiviral Host Factor Against Hepatitis C Virus Infection

HCV infection can decrease NAD⁺/NADH ratio, which could convert lipid metabolism to favor HCV replication. In hepatocytes, quinolinate phosphoribosyl transferase (QPRT) catabolizes quinolinic acid (QA) to nicotinic acid mononucleotide (NAMN) for de novo NAD synthesis. However, whether and how HCV modulates QPRT hence the lipogenesis is unknown. In this work, we found QPRT was reduced significantly in livers of patients or humanized C/O^Tg mice with persistent HCV infection. Mechanistic studies indicated that HCV NS3/4A promoted proteasomal degradation of QPRT through Smurf2, an E3 ubiquitin-protein ligase, in Huh7.5.1 cells. Furthermore, QPRT enzymatic activity involved in suppression of HCV replication in cells. Activation of QPRT with clofibrate (CLO) or addition of QPRT catabolite NAD both inhibited HCV replication in cells, probably through NAD⁺-dependent Sirt1 inhibition of cellular lipogenesis. More importantly, administration of CLO, a hypolipidemic drug used in clinics, could significantly reduce the viral load in HCV infected C/O^Tg mice. Take together, these results suggested that HCV infection triggered proteasomal degradation of QPRT and consequently reduced de novo NAD synthesis and lipogenesis, in favor of HCV replication. Hepatic QPRT thus likely served as a cellular factor that dampened productive HCV replication.

Changing landscape of hepatitis C virus-positive donors

With the introduction of the new highly effective antiviral therapies, there has been a dramatic increase in the use of the hepatitis C virus (HCV)-positive livers in HCV-positive recipients. In the majority of studies, HCV positivity was defined as a donor testing HCV Ab positive. In 2015, all Organ Procurement Organizations were mandated to perform and report HCV Nucleic Acid Amplification Testing (NAT) results on all deceased and living donors. Studies are not yet available on how organs are being utilized based on NAT status and whether NAT status affects recipient outcomes. Further studies are needed to maximize the use of these organs.

Role of primary T-cell immunodeficiency and hepatitis B coinfection on spontaneous clearance of hepatitis C: The BC Hepatitis Testers Cohort

T-cell host immune response against hepatitis C virus (HCV) has been suggested to play an important role in determining HCV infection outcome. However, data from human studies are not available. This study examined the effect of primary T-cell deficiency along with other factors on the spontaneous clearance of HCV in a large population-based cohort in British Columbia, Canada. The BC Hepatitis Testers Cohort includes all individuals tested for HCV in BC in 1990-2013 linked with data on their medical visits, hospitalizations and prescription drugs. HCV-positive individuals with at least one valid HCV PCR test on/after HCV diagnosis (n=46 783) were included in this study. To examine factors associated with the spontaneous clearance of HCV, multivariable logistic regression was fitted on the full sample, and Cox proportional hazards model on the HCV seroconverters. Spontaneous clearance was observed in 25.1% (n=11 737) of those tested for HCV. After adjusting for potential confounders, the odds of spontaneous clearance of HCV was lower in people with primary T-cell immunodeficiency (adjusted odds ratio [aOR]: 0.55, 95% CI: 0.32-0.94), and higher in females (aOR: 1.61, 95% CI: 1.54-1.68) and in those coinfected with HBV (aOR: 2.31, 95% CI: 1.93-2.77). Similar results were observed in HCV seroconverters except HBV coinfection was not significant. In conclusion, primary T-cell immunodeficiency is associated with a lower spontaneous clearance of HCV while female sex and coinfection with HBV are associated with a higher spontaneous clearance.

Modelling CD4 T Cell Recovery in Hepatitis C and HIV Co-infected Children Receiving Antiretroviral Therapy

BACKGROUND

The effect of hepatitis C virus (HCV) coinfection on CD4 T cell recovery in treated HIV-infected children is poorly understood.

OBJECTIVE

To compare CD4 T cell recovery in HIV/HCV coinfected children with recovery in HIV monoinfected children.

METHOD

We studied 355 HIV monoinfected and 46 HIV/HCV coinfected children receiving antiretroviral therapy (ART) during a median follow-up period of 4.2 years (interquartile range: 2.7-5.3 years). Our dataset came from the Ukraine pediatric HIV Cohort and the HIV/HCV coinfection study within the European Pregnancy and Paediatric HIV Cohort Collaboration. We fitted an asymptotic nonlinear mixed-effects model of CD4 T cell reconstitution to age-standardized CD4 counts in all 401 children and investigated factors predicting the speed and extent of recovery.

RESULTS

We found no significant impact of HCV coinfection on either pre-ART or long-term age-adjusted CD4 counts (z scores). However, the rate of increase in CD4 z score was slower in HIV/HCV coinfected children when compared with their monoinfected counterparts (P < 0.001). Both monoinfected and coinfected children starting ART at younger ages had higher pre-ART (P < 0.001) and long-term (P < 0.001) CD4 z scores than those who started when they were older.

CONCLUSIONS

HIV/HCV coinfected children receiving ART had slower CD4 T cell recovery than HIV monoinfected children. HIV/HCV coinfection had no impact on pre-ART or long-term CD4 z scores. Early treatment of HIV/HCV coinfected children with ART should be encouraged.

Extra-epitopic hepatitis C virus polymorphisms confer resistance to broadly neutralizing antibodies by modulating binding to scavenger receptor B1

Broadly-neutralizing monoclonal antibodies (bNAbs) may guide vaccine development for highly variable viruses including hepatitis C virus (HCV), since they target conserved viral epitopes that could serve as vaccine antigens. However, HCV resistance to bNAbs could reduce the efficacy of a vaccine. HC33.4 and AR4A are two of the most potent anti-HCV human bNAbs characterized to date, binding to highly conserved epitopes near the amino- and carboxy-terminus of HCV envelope (E2) protein, respectively. Given their distinct epitopes, it was surprising that these bNAbs showed similar neutralization profiles across a panel of natural HCV isolates, suggesting that some viral polymorphisms may confer resistance to both bNAbs. To investigate this resistance, we developed a large, diverse panel of natural HCV envelope variants and a novel computational method to identify bNAb resistance polymorphisms in envelope proteins (E1 and E2). By measuring neutralization of a panel of HCV pseudoparticles by 10 μg/mL of each bNAb, we identified E1E2 variants with resistance to one or both bNAbs, despite 100% conservation of the AR4A binding epitope across the panel. We discovered polymorphisms outside of either binding epitope that modulate resistance to both bNAbs by altering E2 binding to the HCV co-receptor, scavenger receptor B1 (SR-B1). This study is focused on a mode of neutralization escape not addressed by conventional analysis of epitope conservation, highlighting the contribution of extra-epitopic polymorphisms to bNAb resistance and presenting a novel mechanism by which HCV might persist even in the face of an antibody response targeting multiple conserved epitopes.

Generation of an immune response that is protective against a wide variety of naturally occurring isolates is necessary for vaccines against highly variable viruses like hepatitis C virus (HCV). Two broadly neutralizing human monoclonal antibodies, HC33.4 and AR4A, neutralize multiple highly divergent HCV isolates, raising hope that a vaccine against HCV is possible. Previous reports have defined the distinct, highly conserved sites on the viral envelope proteins where these antibodies bind. However, little is known about naturally occurring variation in sensitivity of different HCV isolates to these antibodies. We developed a high throughput assay and computational algorithm to evaluate over 100 naturally occurring HCV variants for their sensitivity to these two antibodies, identifying several resistance polymorphisms to each antibody which do not fall within their mapped binding sites. Furthermore, two of these polymorphisms modulate resistance to both antibodies by enhancing or reducing envelope protein binding to HCV co-receptor scavenger receptor B1 (SR-B1). By developing this broadly applicable platform, we have shown the important neutralization resistance conferred by changes distant from antibody binding sites, presenting a potential mechanism by which HCV might persist even in the face of an antibody response targeting multiple conserved sites.

Hepatitis C Virus Postexposure Prophylaxis in the Healthcare Worker: Why Direct-Acting Antivirals Don't Change a Thing

Currently, 380 000-400 000 occupational exposures to blood-borne pathogens occur annually in the United States. The management for occupational HIV or hepatitis B virus exposures includes postexposure prophylaxis (PEP) when necessary; however, PEP is not recommended for hepatitis C virus (HCV) exposures. Recent approval of HCV direct-acting antivirals (DAAs) has renewed discussions as to whether these therapies could be used to prevent infection after exposure. There are no published studies addressing this question, but the prescribing of DAAs for PEP has been reported. We will discuss the differences in transmission of the 3 most common blood-borne pathogens, the natural history of early HCV infection, and the scientific rationale for PEP. In particular, we will discuss how the low feasibility of conducting an adequately powered clinical trial of DAA use for PEP and the low cost-effectiveness of such an intervention is not supportive of targeting limited resources for such use.

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.

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.

Hepatitis C Is Poorly Associated With Drug Use in Cambodian Americans in Lowell, Massachusetts

Background. Hepatitis C (HCV) is the most common chronic blood-borne infection in the United States and affects Asian and non-Asian Americans comparably. Injection drug use, the most common national transmission risk, is not as prevalent in Asian-Americans, but prior studies do not include many Cambodian Americans. Lowell, Massachusetts has the second largest population of Cambodian Americans, allowing a direct comparison of HCV-infected Cambodian and non-Cambodian Americans not previously done. Improving our understanding of HCV risks in this unique community may improve their linkage to care.

Methods. In this cross-sectional study, medical data were collected regarding HCV risk factors for HCV-infected Cambodian and non-Cambodian Americans seen at Lowell Community Health Center from 2009 to 2012.

Results. Cambodian Americans (n = 128) were older (mean age 53 vs 43 years old) and less likely to be male (41% vs 67%, P < .001) compared with non-Cambodians (n = 541). Cambodians had lower rates of injection drug use (1.6% vs 33.6%, P < .001) and any drug use (2.3% vs 82.1%, P < .001). More Cambodians were born between 1945 and 1965 (66.4% vs 44.5%). Within this birth cohort, more Cambodians had no other risk factor (82% vs 69%, P = .02). Fewer Cambodians had chronic HCV (53% vs 74%, P < .001).

Conclusions. Birth between 1945 and 1965 was the major HCV risk factor for Cambodian Americans. Cambodians had lower rates of injection drug use or any drug use history. Risk behavior screening fails to describe HCV transmission for Cambodian Americans and creates a barrier to their linkage to care.

CD4+ T-cell recovery with suppressive ART-induced rapid sequence evolution in hepatitis C virus envelope but not NS3

OBJECTIVES

CD4 T-cell depletion from HIV infection leads to a global decline in anti-hepatitis C virus (HCV) envelope neutralizing antibody (nAb) response, which may play a role in accelerating liver fibrosis. An increase in anti-HCV nAb titers has been reported during antiretroviral therapy (ART) but its impact on HCV remains poorly understood. The objective of this study is to determine the effects of ART on long-term HCV evolution.

DESIGN AND METHODS

We examined HCV quasispecies structure and long-term evolution in HIV/HCV coinfected patients with ART-induced CD4 T-cell recovery, and compared with patients with CD4 T-cell depletion from delayed ART. We applied a single-variant sequencing (SVS) method to construct authentic viral quasispecies and compared sequence evolution in HCV envelope, the primary target for humoral immune responses, and NS3, a target for cellular immunity, between the two cohorts.

RESULTS

The SVS method corrected biases known to skew the proportions of viral variants, revealing authentic HCV quasispeices structures. We observed higher rates of HCV envelope sequence evolution in patients with ART-induced CD4 T-cell recovery, compared with patients with CD4 T-cell depletion from delayed ART (P = 0.03). Evolutionary rates for NS3 were considerably lower than the rates for envelope (P < 0.01), with no significant difference observed between the two groups.

CONCLUSION

ART-induced CD4 T-cell recovery results in rapid sequence evolution in HCV envelope, but not in NS3. These results suggest that suppressive ART disproportionally enhances HCV-specific humoral responses more than cellular responses, resulting in rapid sequence evolution in HCV envelope but not NS3.

CD4+ and CD8+ T Cell Activation in Children with Hepatitis C

OBJECTIVES

To assess if peripheral T cell populations in children with chronic hepatitis C virus (HCV) infection would show evidence of activation/exhaustion and an attenuated functional response.

STUDY DESIGN

Compared with adults, children with HCV infection have a higher rate of spontaneous viral clearance. In adults, chronic HCV has been linked to T cell exhaustion. Little is known of the immune status of children with HCV. Peripheral blood mononuclear cells were isolated from 16 children with HCV (6 males, 10 females; mean age 8.6 years, range 2-17), 16 age- and sex-matched control children without HCV infection, and 20 adults with chronic HCV. Multiparameter flow cytometry was performed to characterize T cell differences across the 3 groups.

RESULTS

Controls and children with HCV had similar levels of CD4(+), CD8(+), and γδ(+) T cells. Children with HCV demonstrated a decrease in naïve T cells compared with control children and increased activation/exhaustion marker expression on both CD8(+) and CD4(+) T cells. Transcription factor analysis suggested functional activation of T cells in children with HCV; however, only the CD4(+) subset had enhanced cytokine production (interferon gamma and interleukin-2) compared with control children.

CONCLUSIONS

The HCV response in children is characterized by several changes in T cell phenotype. Many of these changes, such as increased T cell expression of programmed cell death-1, are similar to responses in adults. Of note, cytokine production by CD4(+) helper T cells is increased in children with HCV compared with age- and sex-matched control children, which may influence long-term prognosis in children with HCV.

A Hepatitis C Virus Envelope Polymorphism Confers Resistance to Neutralization by Polyclonal Sera and Broadly Neutralizing Monoclonal Antibodies

Hepatitis C virus (HCV) infection is a global health problem, with millions of chronically infected individuals at risk for cirrhosis and hepatocellular carcinoma. HCV vaccine development is vital in the effort toward disease control and eradication, an undertaking aided by an increased understanding of the mechanisms of resistance to broadly neutralizing antibodies (bNAbs). In this study, we identified HCV codons that vary deep in a phylogenetic tree of HCV sequences and showed that a polymorphism at one of these positions renders Bole1a, a computationally derived, ancestral genotype 1a HCV strain, resistant to neutralization by both polyclonal-HCV-infected plasma and multiple broadly neutralizing monoclonal antibodies with unique binding epitopes. This bNAb resistance mutation reduces replicative fitness, which may explain the persistence of both neutralization-sensitive and neutralization-resistant variants in circulating viral strains. This work identifies an important determinant of bNAb resistance in an ancestral, representative HCV genome, which may inform HCV vaccine development.

IMPORTANCE

Worldwide, more than 170 million people are infected with hepatitis C virus (HCV), the leading cause of hepatocellular carcinoma and liver transplantation in the United States. Despite recent significant advances in HCV treatment, a vaccine is needed. Control of the HCV pandemic with drug treatment alone is likely to fail due to limited access to treatment, reinfections in high-risk individuals, and the potential for resistance to direct-acting antivirals (DAAs). Broadly neutralizing antibodies (bNAbs) block infection by diverse HCV variants and therefore serve as a useful guide for vaccine development, but our understanding of resistance to bNAbs is incomplete. In this report, we identify a viral polymorphism conferring resistance to neutralization by both polyclonal plasma and broadly neutralizing monoclonal antibodies, which may inform HCV vaccine development.