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Viruses Jun 2023According to the World Health Organization, approximately 20 million people worldwide are infected annually with the hepatitis E virus (HEV). There are four main... (Review)
Review
According to the World Health Organization, approximately 20 million people worldwide are infected annually with the hepatitis E virus (HEV). There are four main genotypes of HEV. Genotype 1 and genotype 2 are common in developing countries and are transmitted by contaminated water from a fecal-oral route. Genotype 3 and genotype 4 are common in developed countries and can lead to occasional transmission to humans via undercooked meat. Hepatitis E virus 1 and HEV3 can lead to fulminant hepatitis, and HEV3 can lead to chronic hepatitis and cirrhosis in immunocompromised patients. The majority of patients with HEV infection are asymptomatic and usually have spontaneous viral clearance without treatment. However, infection in immunocompromised individuals can lead to chronic HEV infection. Both acute and chronic HEV infections can have extrahepatic manifestations. No specific treatment is required for acute HEV infection, no treatment has been approved in chronic infection, and no HEV vaccine has been approved by the (United States) Food and Drug Administration. This review focuses on the molecular virology (HEV life cycle, genotypes, model systems, zoonosis), pathogenesis, clinical manifestation, and treatment of chronic HEV infection, especially in immunocompromised patients, to provide clinicians a better understanding of the global distribution of these infections and the significant effect they can have on immunocompromised patients.
Topics: Animals; Humans; Hepatitis E virus; Molecular Epidemiology; Hepatitis E; Zoonoses; Hepatitis, Chronic; Genotype
PubMed: 37376687
DOI: 10.3390/v15061389 -
Clinical and Molecular Hepatology Jul 2023Acute hepatitis C virus (HCV) infection is a global health concern with substantial geographical variation in the incidence rate. People who have received unsafe medical... (Review)
Review
Acute hepatitis C virus (HCV) infection is a global health concern with substantial geographical variation in the incidence rate. People who have received unsafe medical procedures, used injection drugs, and lived with human immunodeficiency virus are reported to be most susceptible to acute HCV infection. The diagnosis of acute HCV infection is particularly challenging in immunocompromised, reinfected, and superinfected patients due to difficulty in detecting anti-HCV antibody seroconversion and HCV ribonucleic acid from a previously negative antibody response. With an excellent treatment effect on chronic HCV infection, recently, clinical trials investigating the benefit of direct-acting antivirals (DAAs) treatment for acute HCV infection have been conducted. Based on the results of cost-effectiveness analysis, DAAs should be initiated early in acute HCV infection prior to spontaneous viral clearance. Compared to the standard 8-12 week-course of DAAs for chronic HCV infection, DAAs treatment duration may be shortened to 6-8 weeks in acute HCV infection without compromising the efficacy. Standard DAA regimens provide comparable efficacy in treating HCV-reinfected patients and DAA-naïve ones. For cases contracting acute HCV infection from HCV-viremic liver transplant, a 12-week course of pangenotypic DAAs is suggested. While for cases contracting acute HCV infection from HCV-viremic non-liver solid organ transplants, a short course of prophylactic or pre-emptive DAAs is suggested. Currently, prophylactic HCV vaccines are unavailable. In addition to treatment scale-up for acute HCV infection, practice of universal precaution, harm reduction, safe sex, and vigilant surveillance after viral clearance remain critical in reducing HCV transmission.
Topics: Humans; Antiviral Agents; Hepacivirus; Hepatitis C, Chronic; Hepatitis C; Liver Transplantation
PubMed: 36800699
DOI: 10.3350/cmh.2022.0349 -
Journal of Hepatology Aug 2023Hepatitis D virus (HDV) infection occurs as a coinfection with hepatitis B and increases the risk of hepatocellular carcinoma, decompensated cirrhosis, and mortality...
Hepatitis D virus (HDV) infection occurs as a coinfection with hepatitis B and increases the risk of hepatocellular carcinoma, decompensated cirrhosis, and mortality compared to hepatitis B virus (HBV) monoinfection. Reliable estimates of the prevalence of HDV infection and disease burden are essential to formulate strategies to find coinfected individuals more effectively and efficiently. The global prevalence of HBV infections was estimated to be 262,240,000 in 2021. Only 1,994,000 of the HBV infections were newly diagnosed in 2021, with more than half of the new diagnoses made in China. Our initial estimates indicated a much lower prevalence of HDV antibody (anti-HDV) and HDV RNA positivity than previously reported in published studies. Accurate estimates of HDV prevalence are needed. The most effective method to generate estimates of the prevalence of anti-HDV and HDV RNA positivity and to find undiagnosed individuals at the national level is to implement double reflex testing. This requires anti-HDV testing of all hepatitis B surface antigen-positive individuals and HDV RNA testing of all anti-HDV-positive individuals. This strategy is manageable for healthcare systems since the number of newly diagnosed HBV cases is low. At the global level, a comprehensive HDV screening strategy would require only 1,994,000 HDV antibody tests and less than 89,000 HDV PCR tests. Double reflex testing is the preferred strategy in countries with a low prevalence of HBV and those with a high prevalence of both HBV and HDV. For example, in the European Union and North America only 35,000 and 22,000 cases, respectively, will require anti-HDV testing annually.
Topics: Humans; Hepatitis B virus; Prevalence; Hepatitis D; Hepatitis B; Hepatitis Delta Virus; Hepatitis B Surface Antigens; Hepatitis Antibodies; Reflex; Coinfection; RNA; Liver Neoplasms
PubMed: 37030400
DOI: 10.1016/j.jhep.2023.02.041 -
Single-cell atlas of the liver myeloid compartment before and after cure of chronic viral hepatitis.Journal of Hepatology Feb 2024Chronic viral infections present serious public health challenges; however, direct-acting antivirals (DAAs) are now able to cure nearly all patients infected with...
BACKGROUND & AIMS
Chronic viral infections present serious public health challenges; however, direct-acting antivirals (DAAs) are now able to cure nearly all patients infected with hepatitis C virus (HCV), representing the only cure of a human chronic viral infection to date. DAAs provide a valuable opportunity to study immune pathways in the reversal of chronic immune failures in an in vivo human system.
METHODS
To leverage this opportunity, we used plate-based single-cell RNA-seq to deeply profile myeloid cells from liver fine needle aspirates in patients with HCV before and after DAA treatment. We comprehensively characterised liver neutrophils, eosinophils, mast cells, conventional dendritic cells, plasmacytoid dendritic cells, classical monocytes, non-classical monocytes, and macrophages, and defined fine-grained subpopulations of several cell types.
RESULTS
We discovered cell type-specific changes post-cure, including an increase in MCM7+STMN1+ proliferating CD1C+ conventional dendritic cells, which may support restoration from chronic exhaustion. We observed an expected downregulation of interferon-stimulated genes (ISGs) post-cure as well as an unexpected inverse relationship between pre-treatment viral load and post-cure ISG expression in each cell type, revealing a link between viral loads and sustained modifications of the host's immune system. We found an upregulation of PD-L1/L2 gene expression in ISG-high neutrophils and IDO1 expression in eosinophils, pinpointing cell subpopulations crucial for immune regulation. We identified three recurring gene programmes shared by multiple cell types, distilling core functions of the myeloid compartment.
CONCLUSIONS
This comprehensive single-cell RNA-seq atlas of human liver myeloid cells in response to cure of chronic viral infections reveals principles of liver immunity and provides immunotherapeutic insights.
CLINICAL TRIAL REGISTRATION
This study is registered at ClinicalTrials.gov (NCT02476617).
IMPACT AND IMPLICATIONS
Chronic viral liver infections continue to be a major public health problem. Single-cell characterisation of liver immune cells during hepatitis C and post-cure provides unique insights into the architecture of liver immunity contributing to the resolution of the first curable chronic viral infection of humans. Multiple layers of innate immune regulation during chronic infections and persistent immune modifications after cure are revealed. Researchers and clinicians may leverage these findings to develop methods to optimise the post-cure environment for HCV and develop novel therapeutic approaches for other chronic viral infections.
Topics: Humans; Antiviral Agents; Persistent Infection; Hepatitis C, Chronic; Hepatitis C; Hepacivirus
PubMed: 36972796
DOI: 10.1016/j.jhep.2023.02.040 -
The Lancet. Public Health Sep 2023In 2016, the World Health Assembly adopted the resolution to eliminate viral hepatitis by 2030. This study aims to provide an overview of the burdens of hepatitis B...
BACKGROUND
In 2016, the World Health Assembly adopted the resolution to eliminate viral hepatitis by 2030. This study aims to provide an overview of the burdens of hepatitis B virus (HBV) and hepatitis C virus (HCV) in Europe and their changes from 2010 to 2019 using estimates from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019.
METHODS
We used GBD 2019 estimates of the burden associated with HBV-related and HCV-related diseases: acute hepatitis, cirrhosis and other chronic liver diseases, and liver cancer. We report total numbers and age-standardised rates per 100 000 for mortality, prevalence, incidence, and disability-adjusted life-years (DALYs) from 2010 to 2019. For each HBV-related and HCV-related disease and each measure, we analysed temporal changes and percentage changes for the 2010-19 period.
FINDINGS
In 2019, across all age groups, there were an estimated 2·08 million (95% uncertainty interval [UI] 1·66 to 2·54) incident cases of acute hepatitis B and 0·49 million (0·42 to 0·57) of hepatitis C in Europe. There were an estimated 8·24 million (7·56 to 8·88) prevalent cases of HBV-related cirrhosis and 11·87 million (9·77 to 14·41) of HCV-related cirrhosis, with 24·92 thousand (19·86 to 31·03) deaths due to HBV-related cirrhosis and 36·89 thousand (29·94 to 45·56) deaths due to HCV-related cirrhosis. Deaths were estimated at 9·00 thousand (6·88 to 11·62) due to HBV-related liver cancer and 23·07 thousand (18·95 to 27·31) due to HCV-related liver cancer. Between 2010 and 2019, the age-standardised incidence rate of acute hepatitis B decreased (-22·14% [95% UI -35·44 to -5·98]) as did its age-standardised mortality rate (-33·27% [-43·03 to -25·49]); the age-standardised prevalence rate (-20·60% [-22·09 to -19·10]) and mortality rate (-33·19% [-37·82 to -28·13]) of HBV-related cirrhosis also decreased in this time period. The age-standardised incidence rate of acute hepatitis C decreased by 3·24% (1·17 to 5·02) and its age-standardised mortality rate decreased by 35·73% (23·48 to 47·75) between 2010 and 2019; the age-standardised prevalence rate (-6·37% [-8·11 to -4·32]), incidence rate (-5·87% [-11·24 to -1·01]), and mortality rate (-11·11% [-16·54 to -5·53]) of HCV-related cirrhosis also decreased. No significant changes were observed in age-standardised rates of HBV-related and HCV-related liver cancer, although we observed a significant increase in numbers of cases of HCV-related liver cancer across all ages between 2010 and 2019 (16·41% [2·81 to 30·91] increase in prevalent cases). Substantial reductions in DALYs since 2010 were estimated for acute hepatitis B (-27·82% [-36·92 to -20·24]), acute hepatitis C (-27·07% [-15·97 to -39·34]), and HBV-related cirrhosis (-30·70% [-35·75 to -25·03]). A moderate reduction in DALYs was estimated for HCV-related cirrhosis (-6·19% [-0·19 to -12·57]). Only HCV-related liver cancer showed a significant increase in DALYs (10·37% [4·81-16·63]). Changes in age-standardised DALY rates closely resembled those observed for overall DALY counts, except for HCV-liver related cancer (-2·84% [-7·75 to 2·63]).
INTERPRETATION
Although decreases in some HBV-related and HCV-related diseases were estimated between 2010 and 2019, HBV-related and HCV-related diseases are still associated with a high burden, highlighting the need for more intensive and coordinated interventions within European countries to reach the goal of elimination by 2030.
FUNDING
Bill & Melinda Gates Foundation.
Topics: Humans; Europe; Global Burden of Disease; Hepatitis B; Hepatitis C; Liver Cirrhosis; Liver Neoplasms
PubMed: 37633679
DOI: 10.1016/S2468-2667(23)00149-4 -
Gut Oct 2023Exhausted T cells with limited effector function are enriched in chronic hepatitis B and C virus (HBV and HCV) infection. Metabolic regulation contributes to exhaustion,...
OBJECTIVE
Exhausted T cells with limited effector function are enriched in chronic hepatitis B and C virus (HBV and HCV) infection. Metabolic regulation contributes to exhaustion, but it remains unclear how metabolism relates to different exhaustion states, is impacted by antiviral therapy, and if metabolic checkpoints regulate dysfunction.
DESIGN
Metabolic state, exhaustion and transcriptome of virus-specific CD8 T cells from chronic HBV-infected (n=31) and HCV-infected patients (n=52 were determined and during direct-acting antiviral (DAA) therapy. Metabolic flux and metabolic checkpoints were tested . Intrahepatic virus-specific CD8 T cells were analysed by scRNA-Seq in a HBV-replicating murine model of acute and chronic infection.
RESULTS
HBV-specific (core, polymerase) and HCV-specific (NS3, NS3, NS5B) CD8 T cell responses exhibit heterogeneous metabolic profiles connected to their exhaustion states. The metabolic state was connected to the exhaustion profile rather than the aetiology of infection. Mitochondrial impairment despite intact glucose uptake was prominent in severely exhausted T cells linked to elevated liver inflammation in chronic HCV infection and in HBV polymerase -specific CD8 T cell responses. In contrast, relative metabolic fitness was observed in HBeAg-negative HBV infection in HBV core-specific responses. DAA therapy partially improved mitochondrial programmes in severely exhausted HCV-specific T cells and enriched metabolically fit precursors. We identified enolase as a metabolic checkpoint in exhausted T cells. Metabolic bypassing improved glycolysis and T cell effector function. Similarly, enolase deficiency was observed in intrahepatic HBV-specific CD8 T cells in a murine model of chronic infection.
CONCLUSION
Metabolism of HBV-specific and HCV-specific T cells is strongly connected to their exhaustion severity. Our results highlight enolase as metabolic regulator of severely exhausted T cells. They connect differential bioenergetic fitness with distinct exhaustion subtypes and varying liver disease, with implications for therapeutic strategies.
Topics: Humans; Animals; Mice; CD8-Positive T-Lymphocytes; Antiviral Agents; Persistent Infection; Hepatitis C, Chronic; Hepatitis B, Chronic; Hepatitis C; Hepatitis Viruses; Hepatitis B virus
PubMed: 37541771
DOI: 10.1136/gutjnl-2022-328734 -
Journal of Hepatology Oct 2023Current therapy for chronic hepatitis B virus (cHBV) infection involves lifelong treatment. New treatments that enable HBV functional cure would represent a clinically...
BACKGROUND & AIMS
Current therapy for chronic hepatitis B virus (cHBV) infection involves lifelong treatment. New treatments that enable HBV functional cure would represent a clinically meaningful advance. ALN-HBV and VIR-2218 are investigational RNA interference therapeutics that target all major HBV transcripts.
METHODS
We report on: i) the safety of single doses of VIR-2218 (modified from ALN-HBV by enhanced stabilization chemistry plus technology to reduce off-target, seed-mediated binding while maintaining on-target antiviral activity) and ALN-HBV in humanized mice; ii) a cross-study comparison of the safety of single doses of VIR-2218 and ALN-HBV in healthy human volunteers (n = 24 and n = 49, respectively); and iii) the antiviral activity of two doses of 20, 50, 100, 200 mg of VIR-2218 (total n = 24) vs. placebo (n = 8), given 4 weeks apart, in participants with cHBV infection.
RESULTS
In humanized mice, alanine aminotransferase (ALT) levels were markedly lower following administration of VIR-2218 compared with ALN-HBV. In healthy volunteers, post-treatment ALT elevations occurred in 28% of participants receiving ALN-HBV compared with none in those receiving VIR-2218. In participants with cHBV infection, VIR-2218 was associated with dose-dependent reductions in hepatitis B surface antigen (HBsAg). The greatest mean reduction of HBsAg at Week 20 in participants receiving 200 mg was 1.65 log IU/ml. The HBsAg reduction was maintained at 0.87 log IU/ml at Week 48. No participants had serum HBsAg loss or hepatitis B surface antibody seroconversion.
CONCLUSIONS
VIR-2218 demonstrated an encouraging hepatic safety profile in preclinical and clinical studies as well as dose-dependent HBsAg reductions in patients with cHBV infection. These data support future studies with VIR-2218 as part of combination regimens with a goal of HBV functional cure.
TRIAL REGISTRATION
ClinicalTrials.gov identifiers: NCT02826018 and NCT03672188.
IMPACT AND IMPLICATIONS
A significant unmet need exists for therapies for chronic HBV (cHBV) infection that achieve functional cure. We report clinical and non-clinical data on two investigational small-interfering RNAs that target HBx, ALN-HBV and VIR-2218, demonstrating that incorporation of enhanced stabilization chemistry plus technology in VIR-2218 reduces its propensity to cause ALT elevations relative to its parent compound, ALN-HBV. We also show that VIR-2218 reduces hepatitis B surface antigen levels in a dose-dependent manner in participants with cHBV infection. These studies support the continued development of VIR-2218 as part of therapeutic regimens for cHBV infection, with the goal of a functional cure, and are important for HBV researchers and physicians.
Topics: Humans; Animals; Mice; Hepatitis B, Chronic; Hepatitis B virus; Hepatitis B Surface Antigens; RNAi Therapeutics; Randomized Controlled Trials as Topic; Antiviral Agents; DNA, Viral; Hepatitis B e Antigens; Hepatitis B
PubMed: 37290591
DOI: 10.1016/j.jhep.2023.05.023 -
Seminars in Liver Disease Aug 2023First discovered over 40 years ago, the hepatitis delta virus (HDV) is a unique RNA virus, requiring hepatitis B virus (HBV) antigens for its assembly, replication, and... (Review)
Review
First discovered over 40 years ago, the hepatitis delta virus (HDV) is a unique RNA virus, requiring hepatitis B virus (HBV) antigens for its assembly, replication, and transmission. HBV and HDV can be acquired at the same time (coinfection) or HDV infection can occur in persons with chronic HBV (superinfection). Screening guidelines for HDV are inconsistent. While some guidelines recommend universal screening for all people with HBV, others recommend risk-based screening. Estimates of the global HDV prevalence range from 4.5 to 14.6% among persons with HBV; thus, there may be up to 72 million individuals with HDV worldwide. HDV is the most severe form of viral hepatitis. Compared to HBV monoinfection, HDV coinfection increases the risk of cirrhosis, hepatocellular carcinoma, hepatic decompensation, mortality, and necessity for liver transplant. Despite the severity of HDV, there are few treatment options. Pegylated interferon (off-label use) has long been the only available treatment, although bulevirtide is conditionally approved in some European countries. There are many potential treatments in development, but as yet, there are few effective and safe therapies for HDV infection. In conclusion, given the severity of HDV disease and the paucity of treatments, there is a great unmet need for HDV therapies.
Topics: Humans; Hepatitis B; Coinfection; Liver Neoplasms; Hepatitis Delta Virus; Hepatitis D; Hepatitis B virus
PubMed: 37473778
DOI: 10.1055/a-2133-8614 -
Annals of Palliative Medicine Nov 2023Cancer immunotherapy has firmly established itself as a pillar of cancer care due to its advantages over traditional anti-tumor therapy but also carries limitations due... (Review)
Review
BACKGROUND AND OBJECTIVE
Cancer immunotherapy has firmly established itself as a pillar of cancer care due to its advantages over traditional anti-tumor therapy but also carries limitations due to potential for severe adverse reactions. This review highlights the current understanding and management of patients with autoimmune and viral hepatitis immune in the setting of immune checkpoint inhibitor (ICI) therapy.
METHODS
A literature search was conducted on PubMed, Scopus, Google Scholar SEER*Stat databases (from inception to December 2022) using search terms: "immune checkpoint inhibitor", "autoimmune hepatitis", "viral hepatitis", "HBV pathogenesis", "HCV pathogenesis", "HBV reactivation", "HCV reactivation", "cancer immunotherapy", "immune related adverse events", "immune related hepatitis".
KEY CONTENT AND FINDINGS
Pre-existing autoimmune disease (AD), whether active or inactive, can predispose patients receiving ICI therapy to develop autoimmune disease flares or immune-related adverse events (irAEs). Thus, patients with AD have routinely been excluded from clinical trials and data on safety of ICI therapy are limited. Hepatic irAE can be seen in ICI therapy and is a distinct entity from autoimmune hepatitis (AIH). ICI therapy alters the immune environment in patients with chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. Patients who had prior exposure to HBV are at risk for viral reactivation. However, the prevalence of viral hepatitis in patients receiving immunotherapy is under-recognized and can lead to increases in liver biochemical tests as well as deterioration of liver function ultimately limiting treatment.
CONCLUSIONS
The high morbidity and mortality associated with immune-related hepatitis emphasizes the need for screening of underlying diseases, including autoimmune and viral hepatitis, prior to initiation of ICI. Presence of AIH or chronic viral hepatitis is the most important risk factor for hepatic adverse events in ICI therapy. Screening for AIH, HBV and HCV is paramount in patients who will undergo ICI therapy.
Topics: Humans; Hepatitis B, Chronic; Hepatitis C; Hepatitis B virus; Autoimmune Diseases; Hepacivirus; Immunotherapy
PubMed: 37731304
DOI: 10.21037/apm-23-250 -
World Journal of Gastroenterology May 2024Viral hepatitis represents a major danger to public health, and is a globally leading cause of death. The five liver-specific viruses: Hepatitis A virus, hepatitis B... (Review)
Review
Viral hepatitis represents a major danger to public health, and is a globally leading cause of death. The five liver-specific viruses: Hepatitis A virus, hepatitis B virus, hepatitis C virus, hepatitis D virus, and hepatitis E virus, each have their own unique epidemiology, structural biology, transmission, endemic patterns, risk of liver complications, and response to antiviral therapies. There remain few options for treatment, in spite of the increasing prevalence of viral-hepatitis-caused liver disease. Furthermore, chronic viral hepatitis is a leading worldwide cause of both liver-related morbidity and mortality, even though effective treatments are available that could reduce or prevent most patients' complications. In 2016, the World Health Organization released its plan to eliminate viral hepatitis as a public health threat by the year 2030, along with a discussion of current gaps and prospects for both regional and global eradication of viral hepatitis. Today, treatment is sufficiently able to prevent the disease from reaching advanced phases. However, future therapies must be extremely safe, and should ideally limit the period of treatment necessary. A better understanding of pathogenesis will prove beneficial in the development of potential treatment strategies targeting infections by viral hepatitis. This review aims to summarize the current state of knowledge on each type of viral hepatitis, together with major innovations.
Topics: Humans; Antiviral Agents; Hepatitis, Viral, Human; Hepatitis Viruses; Prevalence; Liver
PubMed: 38764770
DOI: 10.3748/wjg.v30.i18.2402