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Abstract In this study, a real-time reverse transcription–polymerase chain reaction (real time RT-PCR) assay targeting 2 genetic segments was established to detect HDV RNA. Utilizing the World Health Organization International Standard for Hepatitis D Virus RNA, the lower limit of detection was 575 IU/mL, and the linearity of quantification ranged from 575,000 IU/mL to 575 IU/mL. 384 HBsAg-positive samples collected from China were tested by this method and HDV antibody detection. Eleven samples were positive for anti-HDV IgG which may persist after HDV resolution, 6 samples were HDV RNA positive, and 5 samples were positive for anti-HDV IgM. This assay showed more sensitivity than the detection of anti-HDV IgM. These data demonstrate that the real-time RT-PCR assay for HDV RNA could be implemented in the clinical detection of HDV infection in chronic HBV-infected patients in China. Highlights • No commercially rapid etiological test for HDV infection is available in China. • Dual-targeting real-time RT-PCR assay for HDV RNA was established. • The design of 2 targets could improve the sensitivity of the real time RT-PCR detection. • It was evaluated by WHO international standard and applied in clinical samples. [ABSTRACT FROM AUTHOR]

Hepatitis delta virus (HDV) causes the most severe form of human viral hepatitis and is associated with a higher risk of cirrhosis, liver decompensation and liver cancer. Interferon alpha is the only agent that has demonstrated efficacy to date, although response rates are low and it is associated with significant side effects. A better understanding of the relevant molecular virology has resulted in the identification of new candidate targets. Future therapeutic options are rapidly evolving as several new agents have entered clinical development, including the entry inhibitor myrcludex-B, the nucleic acid polymer REP2139-Ca inhibiting HBV surface antigen secretion, the farnesyltransferase inhibitor lonafarnib that targets virus assembly, and a better tolerated interferon–interferon lambda. [ABSTRACT FROM AUTHOR]

Background & Aims Phosphoinositides (PIs) bind and regulate localization of proteins via a variety of structural motifs. PI 4,5-bisphosphate (PI[4,5]P 2 ) interacts with and modulates the function of several proteins involved in intracellular vesicular membrane trafficking. We investigated interactions between PI(4,5)P 2 and hepatitis C virus (HCV) nonstructural protein 5A (NS5A) and effects on the viral life cycle. Methods We used a combination of quartz crystal microbalance, circular dichroism, molecular genetics, and immunofluorescence to study specific binding of PI(4,5)P2 by the HCV NS5A protein. We evaluated the effects of PI(4,5)P2 on the function of NS5A by expressing wild-type or mutant forms of Bart79I or FL-J6/JFH-5’C19Rluc2AUbi21 RNA in Huh7 cells. We also studied the effects of strategies designed to inhibit PI(4,5)P 2 on HCV replication in these cells. Results The N-terminal amphipathic helix of NS5A bound specifically to PI(4,5)P 2 , inducing a conformational change that stabilized the interaction between NS5A and TBC1D20, which is required for HCV replication. A pair of positively charged residues within the amphipathic helix (the basic amino acid PI(4,5)P2 pincer domain) was required for PI(4,5)P 2 binding and replication of the HCV-RNA genome. A similar motif was found to be conserved across all HCV isolates, as well as amphipathic helices of many pathogens and apolipoproteins. Conclusions PI(4,5)P 2 binds to HCV NS5A to promote replication of the viral RNA genome in hepatocytes. Strategies to disrupt this interaction might be developed to inhibit replication of HCV and other viruses. [ABSTRACT FROM AUTHOR]

Therapy for hepatitis C virus (HCV) infection is on the cusp of a new era. Until now, standard-of-care therapy has involved interferon (IFN) and ribavirin. With the first successful Phase III trials of specific targeted antiviral therapy for HCV (STAT-C) compounds, as well as three trials in progress giving the first glimpse of IFN-free combinations of STAT-C agents, this review looks ahead to the new classes of anti-HCV agents currently in clinical development. Successful pharmacologic control of HIV and TB frames the discussion, as well as consideration of the mutation frequency of HCV replication. Maximizing synergy between agents and minimizing cumulative toxicity will be critical to the design of future IFN-free STAT-C regimens. [ABSTRACT FROM AUTHOR]

Background & Aims: New therapies are needed to treat patients infected with hepatitis C virus (HCV), a major worldwide cause of chronic liver disease. Nitazoxanide (NTZ), originally used to treat cryptosporidiosis infection, recently was shown to have unexpected antiviral activity in the HCV replicon system and in chronically infected patients. A pilot clinical study suggested that NTZ can augment the antiviral effect of interferon (IFN), although the molecular basis for its effect was unknown. Methods: We analyzed the effects of NTZ on the regulation of eukaryotic initiation factor-2α (eIF2α) and its IFN-induced kinase, protein kinase activated by double-stranded RNA (PKR), in cells that support HCV RNA replication and in vitro biochemical assays. Results: NTZ increased eIF2α phosphorylation, a modification known to mediate host cell antiviral defenses. The addition of IFN to cell cultures increased NTZ-induced eIF2α phosphorylation. NTZ also increased PKR phosphorylation. In vitro, NTZ promoted PKR autophosphorylation, a key step in activating PKR''s kinase activity for eIF2α. Finally, NTZ-induced eIF2α phosphorylation was reduced in the presence of specific inhibitors of PKR autophosphorylation. Conclusions: An important mechanism of NTZ''s action involves activation of PKR, a key kinase that regulates the cell''s innate antiviral response. These observations could explain the clinical antiviral effect of NTZ. NTZ might represent a new class of small molecules capable of potentiating and recapitulating important antiviral effects of IFN. [Copyright &y& Elsevier]

Trends of mortality associated with extrahepatic complications of chronic liver disease might be changing. We studied trends in mortality from extrahepatic complications of viral hepatitis, alcoholic liver disease (ALD), and nonalcoholic fatty liver disease in the United States. We performed a population-based study using US Census and the National Center for Health Statistics mortality records from 2007 through 2017. We identified trends in age-standardized mortality using Joinpoint trend analysis with estimates of annual percent change. The liver-related mortality among patients with hepatitis C virus (HCV) infection increased from 2007 through 2013 and then decreased once patients began receiving treatment with direct-acting antiviral (DAA) agents, from 2014 through 2017. Among patients with HCV infection, the age-standardized mortality for extrahepatic cancers was 2.6%, for cardiovascular disease was 1.9%, and for diabetes was 3.3%. Among individuals with hepatitis B virus infection, liver-related mortality decreased steadily from 2007 through 2017. During the study, age-standardized mortality from hepatitis B virus–related extrahepatic complications increased by an average of 2.0% each year. Although liver-related mortality from ALD continued to increase, mortality from extrahepatic complications of ALD did not change significantly during the 11-year study. Among patients with nonalcoholic fatty liver disease, the cause of death was most frequently cardiovascular disease, which increased gradually over the study period, whereas liver-related mortality increased rapidly. In an analysis of US Census and the National Center for Health Statistics mortality records, we found that after widespread use of DAA agents for treatment of viral hepatitis, cause-specific mortality from extrahepatic cancers increased, whereas mortality from cardiovascular disease or diabetes increased only among patients with HCV infection. These findings indicate the need to reassess risk and risk factors for extrahepatic cancer, cardiovascular disease, and diabetes in individuals successfully treated for HCV infection with DAA agents. [ABSTRACT FROM AUTHOR]

Hepatitis delta virus (HDV) infection of humans was first reported in 1977, and now it is now estimated that 15–20 million people are infected worldwide. Infection with HDV can be an acute or chronic process that occurs only in patients with an hepatitis B virus infection. Chronic HDV infection commonly results in the most rapidly progressive form of viral hepatitis; it is the chronic viral infection that is most likely to lead to cirrhosis, and it is associated with an increased risk of hepatocellular carcinoma. HDV infection is the only chronic human hepatitis virus infection without a therapy approved by the US Food and Drug Administration. Peginterferon alfa is the only recommended therapy, but it produces unsatisfactory results. We review therapeutic agents in development, designed to disrupt the HDV life cycle, that might benefit patients with this devastating disease. [ABSTRACT FROM AUTHOR]

Background & Aims Although treatment of hepatitis C virus (HCV) infection has improved, the prevalence of alcoholic liver disease (ALD) has been increasing, so we need an updated estimate of the burden and etiology-specific mortality of chronic liver diseases. We studied trends in age-standardized mortality of chronic liver diseases in adults at least 20 years old in the United States from 2007 through 2016. Methods We collected data from the US Census and National Center for Health Statistics mortality records and identified individuals with HCV infection, ALD, nonalcoholic fatty liver disease, or hepatitis B virus infection using ICD-10 codes. We obtained temporal mortality rate patterns using joinpoint trend analysis with estimates of annual percentage change (APC). Results Age-standardized HCV-related mortality increased from 7.17 per 100,000 persons in 2007 to 8.14 per 100,000 persons in 2013, followed by a marked decrease in the time period at which patients began receiving treatment with direct-acting antiviral agents (from 8.09 per 100,000 persons in 2014 to 7.15 per 100,000 persons in 2016). The APC in HCV mortality increased 2.0%/year from 2007 through 2014 but decreased 6.4%/year from 2014 through 2016. In contrast, age-standardized mortality increased for ALD (APC 2.3% from 2007 through 2013 and APC 5.5% from 2013 through 2016) and nonalcoholic fatty liver disease (APC 6.1% from 2007 through 2013 and APC 11.3% from 2013 through 2016). Mortality related to hepatitis B virus decreased steadily from 2007 through 2016, with an average APC of −2.1% (95% CI −3.0 to −1.2). Etiology-based mortality in minority populations was higher. HCV-related mortality (per 100,000 persons) was highest in non-Hispanic blacks (10.28) and whites (6.92), followed by Hispanics (5.94), and lowest in non-Hispanic Asians (2.33). Non-Hispanic Asians had higher mortality for hepatitis B virus infection (2.82 per 100,000 vs 1.02 for non-Hispanic blacks and 0.47 for non-Hispanic whites). Conclusion In our population-based analysis of chronic liver disease mortality in the United States, the decrease in HCV-related mortality coincided with the introduction of direct-acting antiviral therapies, whereas mortality from ALD and nonalcoholic fatty liver disease increased during the same period. Minorities in the United States have disproportionately higher mortality related to chronic liver disease. Graphical abstract [ABSTRACT FROM AUTHOR]

As we improve our understanding of the molecular virology of hepatitis C virus (HCV), a variety of new potential antiviral strategies are emerging. Moving beyond interferon and ribavirin, these new strategies for the first time are aimed at HCV-specific targets. It is expected, by analogy with other infections, that effective pharmacologic control of HCV will be achieved best by using a cocktail of such virus-specific agents, each designed against an independent target. As a result, the way we treat HCV should change dramatically over the next few years. [Copyright &y& Elsevier]

Summary Chronic hepatitis delta represents the most severe form of chronic viral hepatitis. The current treatment of hepatitis delta virus (HDV) infection consists of the use of interferons and is largely unsatisfactory. Several new compounds are currently in development for the treatment of HDV infection. However, surrogate markers that can be used to develop clinical endpoints in HDV infection are not well defined. In the current manuscript, we aimed to evaluate the existing data on treatment of HDV infection and to suggest treatment goals (possible "trial endpoints") that could be used across different clinical trials. [ABSTRACT FROM AUTHOR]

Abstract Generation of human organoids from induced pluripotent stem cells (iPSCs) offers exciting possibilities for developmental biology, disease modelling and cell therapy. Significant advances towards those goals have been hampered by dependence on animal derived matrices (e.g. Matrigel), immortalized cell lines and resultant structures that are difficult to control or scale. To address these challenges, we aimed to develop a fully defined liver organoid platform using inverted colloid crystal (ICC) whose 3-dimensional mechanical properties could be engineered to recapitulate the extracellular niche sensed by hepatic progenitors during human development. iPSC derived hepatic progenitors (IH) formed organoids most optimally in ICC scaffolds constructed with 140 μm diameter pores coated with type I collagen in a two-step process mimicking liver bud formation. The resultant organoids were closer to adult tissue, compared to 2D and 3D controls, with respect to morphology, gene expression, protein secretion, drug metabolism and viral infection and could integrate, vascularise and function following implantation into livers of immune-deficient mice. Preliminary interrogation of the underpinning mechanisms highlighted the importance of TGFβ and hedgehog signalling pathways. The combination of functional relevance with tuneable mechanical properties leads us to propose this bioengineered platform to be ideally suited for a range of future mechanistic and clinical organoid related applications. [ABSTRACT FROM AUTHOR]

Background: Therapies for chronic hepatitis delta virus (HDV) infection are unsatisfactory. Prenylation is essential for HDV and inhibition abrogates HDV production in experimental models. In a proof-of-concept study, we aimed to assess the effect on HDV RNA levels, safety, and tolerability of the prenylation inhibitor lonafarnib in patients with chronic delta hepatitis.Methods: In this phase 2A double-blind, randomised, placebo-controlled study, patients aged 18 years or older with chronic HDV infection were randomly assigned (3:1 in group 1 and 2:1 in group 2) to receive lonafarnib 100 mg (group 1) or lonafarnib 200 mg (group 2) twice daily for 28 days with 6 months' follow-up. Participants were randomised by random-number tables blocked in groups of four without stratification. Both groups enrolled six treatment participants and two placebo participants. Group 1 placebo patients received open-label lonafarnib as group 2 participants. The primary therapeutic endpoint was a decrease in HDV RNA viral titre in serum and the primary safety endpoint was the ability to tolerate the drug at the prescribed dose for the full 4-week duration, defined as drug discontinuation due to intolerance or grade 3/4 adverse events. This trial is registered with ClinicalTrials.gov, number NCT01495585.Findings: Between Jan 19, 2012, and April 28, 2014, 14 patients were enrolled, of whom eight were assigned to group 1 and six were assigned to group 2. At day 28, compared with placebo, mean log HDV RNA declines from baseline were -0·73 log IU/mL in group 1 (95% CI 0·17-1·31; p=0·03) and -1·54 log IU/mL in group 2 (1·21-1·93; p<0·0001). Lonafarnib serum concentrations correlated with HDV RNA change (r(2)=0·78, p<0·0001). Model fits show that hepatitis B surface antigen (HBsAg) remained stable after a short pharmacological delay (0·75 days [SE 0·24]), lonafarnib effectiveness in blocking HDV production was greater in group 2 than in group 1 (0·952 [SE 0·06] vs 0·739 [0·05], p<0·001), and the HDV half-life was 1·62 days (0·07). There was no evidence of virological resistance. Adverse events were mainly mild to moderate with group 1 patients experiencing diarrhoea in three patients (50%) and nausea in two patients (33%) and in group 2 with all patients (100%) experiencing nausea, diarrhoea, abdominal bloating, and weight loss greater than 2 kg (mean of 4 kg). No treatment discontinuations occurred in any treatment groups.Interpretation: Treatment of chronic HDV with lonafarnib significantly reduces virus levels. The decline in virus levels significantly correlated with serum drug levels, providing further evidence for the efficacy of prenylation inhibition in chronic HDV.Funding: National Institute of Diabetes and Digestive and Kidney Diseases and National Cancer Institute, National Institutes of Health, and Eiger Biopharmaceuticals Inc. [ABSTRACT FROM AUTHOR]

Abstract: Two series of peptidomimetics were designed, prepared and evaluated for their anti-HCV activity. One series possesses a C-terminal carboxylate functionality. In the other series, the electrophilic vinyl sulfonate moiety was introduced as a novel class of HCV NS3/4A protease inhibitors. In vitro based studies were then performed to evaluate the efficacies of the inhibitors using Human hepatoma cells, with the vinyl sulfonate ester (10) in particular, found to have highly potent anti-HCV activity with an EC50 =0.296μM. Finally, molecular modeling studies were performed through docking of the synthesized compounds in the HCV NS3/4A protease active site to assess their binding modes with the enzyme and gain further insight into their structure–activity relationships. [Copyright &y& Elsevier]

Abstract: Biodegradable polymer microspheres have been successfully utilized as a medium for controlled protein or peptide-based drug release. Because the release kinetics has been typically controlled by modulating physical or chemical properties of the medium, these parameters must be optimized to obtain a specific release profile. However, due to the complexity of the release mechanism and the complicated interplay between various design parameters of the release medium, detailed prediction of the resulting release profile is a challenge. Herein we suggest a simple method to target specific release profiles more efficiently by integrating release profiles for an array of different microsphere types. This scheme is based on our observation that the resulting release profile from a mixture of different samples can be predicted as the linear summation of the individually measured release profiles of each sample. Hence, by employing a linear equation at each time point and formulating them as a matrix equation, we could determine how much of each microsphere type to include in a mixture in order to have a specific release profile. In accordance with this method, several targeted release profiles were successfully obtained. We expect that the proposed method will allow us to overcome limitations in controlling complicated release mechanisms so that drug delivery systems can be reliably designed to satisfy clinical demands. [Copyright &y& Elsevier]

Like other viruses, productive hepatitis C virus (HCV) infection depends on certain critical host factors. We have recently shown that an interaction between HCV nonstructural protein NSSA and a host protein, TBC1D20, is necessary for efficient HCV replication. TBC1D20 contains a TBC (Tre-2, Bub2, and Cdc16) domain present in most known Rab GTPase-activating proteins (GAPs). The latter are master regulators of vesicular membrane transport, as they control the activity of membrane-associated Rab proteins. To better understand the role of the NS5A-TBC1D20 interaction in the HCV life cycle, we used a biochemical screen to identify the TBC1D20 Rab substrate. TBC1D20 was found to be the first known GAP for Rab1, which is implicated in the regulation of anterograde traffic between the endoplasmic reticulum and the Golgi complex. Mutation of amino acids implicated in Rab GTPase activation by other TBC domain-containing GAPs abrogated the ability of TBC1D20 to activate Rab1 GTPase. Overexpression of TBC1D20 blocked the transport of exogenous vesicular stomatitis virus G protein from the endoplasmic reticulum, validating the involvement of TBC1D20 in this pathway. Rab1 depletion significantly decreased HCV RNA levels, suggesting a role for Rab1 in HCV replication. These results highlight a novel mechanism by which viruses can hijack host cell machinery and suggest an attractive model whereby the NS5A-TBC1D20 interaction may promote viral membrane-associated RNA replication. [ABSTRACT FROM AUTHOR]