Hepatotropic Viruses Research Articles

A preregistered meta-meta-analysis on the global distribution of Hepatotropic Viruses

Introduction. Hepatotropic viruses (HAV, HBV, HCV, HDV, and HEV) significantly impact global health, with varying prevalence across regions. Objective. This study aims to systematically consolidate data from diverse meta-analyses to provide a contemporary reference on virus distribution and prevalence. Materials and methods. Adhering to PRISMA guidelines, the study utilized a mixed effects model for data integration. Quality evaluation was carried out with QUOROM and AMSTAR tools, with heterogeneity assessed via the Higgins I2 statistic, Q-statistic and Tau squared (τ2) values. Results. The study analyzed 86 meta-analyses from 56 studies (2017–2022) with minimal overlap. Prevalence rates by region were as follows: MENA – 29.2%, Afghanistan – 9.14%, Africa – 8.10%. Prevalence rates by virus type: HAV – 82.5%, HBV – 8.6%, HCV – 15.1%, HDV – 8.9%, HEV – 13.9%, dual HBV-HCV coinfection – 2.2%. Prevalence rates by risk groups: general population – 8.3%, healthcare workers – 4.0%. Continent-specific HBV-HCV prevalence rates: Africa – 9.2%, China – 6.9%, others. HCVprevalence rates among at-risk groups: healthcare workers – 5.58%, hemodialysis patients – 34.8%. Regional HCV rates: Africa – 7.42%, Middle East – 25.30%. Conclusion. Diverse global hepatotropic virus prevalence patterns are influenced by multifaceted factors. MENA faces higher rates due to healthcare challenges, while Africa struggles with limited resources. Tailored public health strategies, including vaccination and awareness campaigns, are essential to alleviate burdens and enhance global health. This consolidated data serves as a valuable resource for informed decision-making.

Hidden liver-joint axis: HBV infection causes rheumatoid arthritis via TRAFD1 with imbalance of HBV X protein and trans-ferulic acid

ABSTRACT Background Liver metabolites are involved in the progression of rheumatoid arthritis (RA), indicating a connection between the liver and joints. However, the impact and mechanism of Hepatitis B virus (HBV), a hepatotropic virus, on RA are still unclear. Methods We investigated the correlation between HBV and RA using Mendelian randomization analysis. Single-cell transcriptome analysis was conducted to investigate changes in cell subtypes in synovial tissue of HBV-RA patients. Fibroblast-like synoviocytes (FLS) were used to create a cell model, and the transcriptome was examined to identify the key downstream molecules of FMT regulated by HBx. CIA model was constructed using HBV transgenic, HBx transgenic, and TRADF1 knockout mice to investigate the impact and mechanism of HBV on CIA. Results The results of our study revealed a significant positive correlation between HBV and RA. The functional studies identified a crucial role of fibroblast-myofibroblast transition (FMT) in the progression of RA. The results suggest that HBV-encoded HBx may promote FMT in RA by upregulating TRAFD1. Furthermore, trans-ferulic acid (TFA) was identified by screening for common metabolites in the liver, joints, and peripheral blood using the metabolome and WGCNA. Interestingly, we found that TFA ameliorated HBx-induced RA by suppressing TRAFD1 expression. Conclusions Our study demonstrates that hidden liver-joint axis, an imbalance between TFA and HBx, plays a critical role in HBV-induced RA, which could be a potential strategy for preventing RA development.

Hepatitis B virus entry, assembly, and egress.

SUMMARYHepatitis B virus (HBV) is an important human pathogen that chronically infects approximately 250 million people in the world, resulting in ~1 million deaths annually. This virus is a hepatotropic virus and can cause severe liver diseases including cirrhosis and hepatocellular carcinoma. The entry of HBV into hepatocytes is initiated by the interaction of its envelope proteins with its receptors. This is followed by the delivery of the viral nucleocapsid to the nucleus for the release of its genomic DNA and the transcription of viral RNAs. The assembly of the viral capsid particles may then take place in the nucleus or the cytoplasm and may involve cellular membranes. This is followed by the egress of the virus from infected cells. In recent years, significant research progresses had been made toward understanding the entry, the assembly, and the egress of HBV particles. In this review, we discuss the molecular pathways of these processes and compare them with those used by hepatitis delta virus and hepatitis C virus , two other hepatotropic viruses that are also enveloped. The understanding of these processes will help us to understand how HBV replicates and causes diseases, which will help to improve the treatments for HBV patients.

Phosphorylation of Ser711 residue in the hypervariable region of zoonotic genotype 3 hepatitis E virus is important for virus replication.

Hepatitis E virus (HEV) is distinct from other hepatotropic viruses because it is zoonotic. HEV-1 and HEV-2 exclusively infect humans, whereas HEV-3 and HEV-4 are zoonotic. However, the viral and/or host factors responsible for cross-species HEV transmission remain elusive. The hypervariable region (HVR) in HEV is extremely heterogenetic and is implicated in HEV adaptation. Here, we investigated the potential role of Serine phosphorylation in the HVR in HEV replication. We first analyzed HVR sequences across different HEV genotypes and identified a unique region at the N-terminus of the HVR, which is variable in the human-exclusive HEV genotypes but relatively conserved in zoonotic HEV genotypes. Using predictive tools, we identified four potential phosphorylation sites that are highly conserved in zoonotic HEV-3 and HEV-4 genomes but absent in human-exclusive HEV-1 strains. To explore the functional significance of these putative phosphorylation sites, we introduced mutations into the HEV-3 infectious clone and indicator replicon, replacing each Serine residue individually with alanine or aspartic acid, and assessed the impact of these substitutions on HEV-3 replication. We found that the phospho-blatant S711A mutant significantly reduced virus replication, whereas the phospho-mimetic S711D mutant modestly reduced virus replication. Conversely, mutations in the other three Serine residues did not significantly affect HEV-3 replication. Furthermore, we demonstrated that Ser711 phosphorylation did not alter host cell tropism of zoonotic HEV-3. In conclusion, our results showed that potential phosphorylation of the Ser711 residue significantly affects HEV-3 replication in vitro, providing new insights into the potential mechanisms of zoonotic HEV transmission.IMPORTANCEHEV is an important zoonotic pathogen, causing both acute and chronic hepatitis E and extrahepatic manifestation of diseases, such as neurological sequelae. The zoonotic HEV-3 is linked to chronic infection and neurological diseases. The specific viral and/or host factors facilitating cross-species HEV infection are unknown. The intrinsically disordered HVR in ORF1 is crucial for viral fitness and adaptation, both in vitro and in vivo. We hypothesized that phosphorylation of Serine residues in the HVR of zoonotic HEV by unknown host cellular kinases is associated with cross-species HEV transmission. In this study, we identified a conserved region within the HVR of zoonotic HEV strains but absent in the human-exclusive HEV-1 and HEV-2. We elucidated the important role of phosphorylation at the Ser711 residue in zoonotic HEV-3 replication, without altering the host cell tropism. These findings contribute to our understanding the mechanisms of cross-species HEV transmission.

Seroprevalence of hepatitis B and hepatitis C virus among clinically suspected cases of viral hepatitis visiting Guhalla Primary Hospital, Northwest Ethiopia

Hepatitis B virus and hepatitis C virus remains one of the leading causes of morbidity and mortality worldwide, particularly in countries with limited resources. The two hepatotropic viruses have common mode of transmission. Hepatitis B virus and hepatitis C virus are the main causes of Cirrhosis, liver cancer and death. To determine the Seroprevalence of HBsAg and anti-HCV antibodies among clinically suspected cases of viral hepatitis visiting Guhalla Primary Hospital, Northwest Ethiopia. A hospital-based retrospective study was conducted at Guhalla Primary Hospital, Northwest Ethiopia. The study included serology registration logbook data from all patients who visited the hospital and were tested using a rapid test kit between September 1st, 2017 to August 30, 2021. Data were entered, cleaned, and analyzed using SPSS version 26 software. Bivariate analysis was computed and a multivariable analysis was conducted to provide an adjusted odds ratio (AOR). p-value < 0.05 at a 95% confidence interval was considered statistically significant. In this study, a total of 883(883 for HBV and 366 for HCV) study participants were included. The overall prevalence of HBsAg and anti-HCV were 124/883(14%) and 73/366 (19.9%), respectively. The prevalence of HBV and HCV among males from the total HBV and HCV screened was 70/410 (17.1%) and 53/366(14.4%) respectively. In this study, being female (AOR 1.53, 95% CI 1.03–2.27, p = 0.003) and age group of 31–40 years (AOR 2.85; 95% CI 1.56, 5.17, p = 0.001) were statistically significant factors to HBV infection. Similarly, being female (AOR 1.97, 95% CI 1.10–3.53, p = 0.02), age group of 21–30 years (AOR 2.71; 95% CI 1.15, 6.40, p = 0.02) and age group greater than 40 years (AOR 3.13; 95% CI 1.31, 7.44, p = 0.01) were significantly associated with HCV infection. In our study, high seroprevalence of HBV and HCV infection was detected among clinically suspected patients. Females and the age groups between 31 and 40 were more affected. Community awareness of the prevention and transmission of viral hepatitis infection should be strengthened through herd immunization and health education. The prospective study should be conducted in this area.

The loss of hepatitis B virus receptor NTCP/SLC10A1 in human liver cancer cells is due to epigenetic silencing.

HBV is a hepatotropic virus that infects human hepatocytes expressing the viral receptor hNTCP. Without effective antiviral therapy, chronic HBV infection poses a high risk of liver cancer. However, most liver cancer cell lines, including HepG2 and Huh7, do not support HBV infection due to the absence of hNTCP expression, and the mechanism underlying this defect remains unclear. This study demonstrates a significant reduction of hNTCP in hepatocellular carcinoma samples and HepG2 cells compared to normal liver tissues and primary human hepatocytes. Despite identical hNTCP genetic sequences, epigenetic analyses revealed a loss of the activating histone modification H3K27ac near the hNTCP transcription start site in cancer cells. Treatment with histone deacetylase inhibitors restored H3K27ac levels, reactivated hNTCP expression, and rendered HepG2 cells susceptible to HBV infection. These findings highlight the role of epigenetic modulation in hNTCP dysregulation, offering insights into hepatocarcinogenesis and its implications for chronic HBV infection.

EXTRAHEPATIC MANIFESTATIONS IN PATIENTS WITH ACUTE HEPATITIS E – PAZARDZHIK, BULGARIA 2014 – 2022

BACKGROUND: Hepatitis E is a global health issue, only partially understood. Bulgarian record started in 2019 and data is not sufficient. AIM: This research aims to analyze extrahepatic manifestation of acute hepatitis E in patients with hepatitis E from Pazardzhik region, between 2014 – 2022. MATERIALS AND METHODS: The analysis includes 247 patients with acute hepatitis E, treated at the Department of Infectious Diseases of Pazardzhik Multiprofile Hospital for Active Treatment, Bulgaria between 2014 – 2022. The methodology includes clinical observation, laboratory tests and medical imaging. The diagnosis was established by serological /ELISA for anti-HEV IgM, IgG detection/and molecular-biological tests /RT-PCR for HEV RNA detection/. RESULTS: We observed extrahepatic manifestations in 19% (47/247) of the cases. In 60% (28/47) comorbidities were present, and 9% (4/47) were with underlying acute/chronic coinfection with another hepatotropic virus. Thrombocytopenia was found in 83% (39/47) of the patients; asymptomatic creatine kinase elevation – in 13% (6/47), acute pancreatitis – in 9% (4/47), transitory renal impairent – in 6% (3/47); 2% (1/47) had Guillain-Barré syndrome (GBS), 2% (1/47) – arrhythmia and 13% (6/47) – multiorgan involvement. While 91% (43/47) of the patients recovered, in 9% (4/47) the outcome was fatal. CONCLUSION: Extrahepatic manifestations might prevail, potentially delaying diagnosis of HEV-infection. Symptoms associated with comorbidities might also impede the final diagnosis. A diagnostic algorithm is needed to enhance the accurate diagnosis of HEV in patients with dubious symptoms.

The Role of Epigenetic Mechanisms in the Pathogenesis of Hepatitis C Infection.

Hepatitis C virus (HCV) is a hepatotropic virus that can be transmitted through unsafe medical procedures, such as injections, transfusions, and dental treatment. The infection may be self-limiting or manifest as a chronic form that induces liver fibrosis, cirrhosis, or progression into hepatocellular carcinoma (HCC). Epigenetic mechanisms are major regulators of gene expression. These mechanisms involve DNA methylation, histone modifications, and the activity of non-coding RNAs, which can enhance or suppress gene expression. Abnormal activity or the dysregulated expression of epigenetic molecules plays an important role in the pathogenesis of various pathological disorders, including inflammatory diseases and malignancies. In this review, we summarise the current evidence on epigenetic mechanisms involved in HCV infection and progression to HCC.

Disease modifiers and novel markers in HBV-related HCC.

Chronic hepatitis B (CHB) infection is responsible for 40% of the global burden of hepatocellular carcinoma (HCC) with a high case fatality rate. The risk of HCC differs among CHB subjects owing to differences in host and viral factors. Modifiable risk factors include viral load, use of antiviral therapy, co-infection with other hepatotropic viruses, concomitant metabolic dysfunction-associated steatotic liver disease or diabetes mellitus, environmental exposure, and medication use. Detecting HCC at early stage improves survival, and current practice recommends HCC surveillance among individuals with cirrhosis, family history of HCC, or above an age cut-off. Ultrasonography with or without serum alpha feto-protein every 6 months is widely accepted strategy for HCC surveillance. Novel tumor-specific markers, when combined with AFP, improve diagnostic accuracy than AFP alone to detect HCC at an early stage. To predict the risk of HCC, a number of clinical risk scores have been developed but none of them are clinically implemented nor endorsed by clinical practice guidelines. Biomarkers that reflect viral transcriptional activity and degree of liver fibrosis can potentially stratify the risk of HCC, especially among subjects who are already on antiviral therapy. Ongoing exploration of these novel biomarkers is required to confirm their performance characteristics, replicability and practicability.

Acute viral hepatitis

Acute inflammation of the liver (hepatitis) can be triggered by at least five different hepatotropic viruses - hepatitis viruses A, B, C, D and E. Hepatitis viruses A and E are transmitted via contaminated food and smear infections, whereas hepatitis viruses B, C and D are transmitted through direct contact with blood and other body fluids when these penetrate the skin or mucous membranes. This article is intended to provide a brief overview of the different forms of acute viral hepatitis, diagnosis, course and treatment.

Seroprevalence and Seroconversion of Hepatitis B and C Viruses in Patients Undergoing Hemodialysis: A Cross-sectional Study.

Among hemodialysis patients, hepatitis B virus (HBV) and hepatitis C virus (HCV)infections contribute significantly to mortality and morbidity. Infection with these hepatotropic viruses in hemodialysis patients is due to their increased contact with blood and its derivatives. Additionally, not following the proper protocol for infection control, contaminated devices, and untrained personnel contribute to the nosocomial transmission of these infections. This cross-sectional study was planned to estimate the seroprevalence of hepatitis B surface antigen (HBsAg) and anti-hepatitis C virus antibodies in patients to know the seroconversion rate for hepatitis B and hepatitis C and to evaluate the risk factors that contribute to seroconversion in patients undergoing hemodialysis at our center. This study included 185 patients with chronic kidney disease undergoing hemodialysis in our center. After giving informed consent, a blood sample from each patient was collected for testing for HBsAg and anti-HCV antibodies initially and then every month. Of the total 185 patients, five participants tested positive for HBV (2.7%), and 29 individuals tested positive for HCV (15.67%). During the study period, seroconversion for hepatitis C was observed in three patients (1.62%), and seroconversion for hepatitis B was observed in one patient (0.54%). An evaluation of the potential risk factors revealed that dialysis conducted outside the facility contributed significantly to HCV infection. Our study shows lower HBV rates but higher HCV rates. The demographic data of the patients and the duration of dialysis are related to the risk of infection. Dialysis within the same healthcare facilities reduces the transmission risk.

A liver immune rheostat regulates CD8 T cell immunity in chronic HBV infection

Chronic hepatitis B virus (HBV) infection affects 300 million patients worldwide1,2, in whom virus-specific CD8 T cells by still ill-defined mechanisms lose their function and cannot eliminate HBV-infected hepatocytes3–7. Here we demonstrate that a liver immune rheostat renders virus-specific CD8 T cells refractory to activation and leads to their loss of effector functions. In preclinical models of persistent infection with hepatotropic viruses such as HBV, dysfunctional virus-specific CXCR6+ CD8 T cells accumulated in the liver and, as a characteristic hallmark, showed enhanced transcriptional activity of cAMP-responsive element modulator (CREM) distinct from T cell exhaustion. In patients with chronic hepatitis B, circulating and intrahepatic HBV-specific CXCR6+ CD8 T cells with enhanced CREM expression and transcriptional activity were detected at a frequency of 12–22% of HBV-specific CD8 T cells. Knocking out the inhibitory CREM/ICER isoform in T cells, however, failed to rescue T cell immunity. This indicates that CREM activity was a consequence, rather than the cause, of loss in T cell function, further supported by the observation of enhanced phosphorylation of protein kinase A (PKA) which is upstream of CREM. Indeed, we found that enhanced cAMP–PKA-signalling from increased T cell adenylyl cyclase activity augmented CREM activity and curbed T cell activation and effector function in persistent hepatic infection. Mechanistically, CD8 T cells recognizing their antigen on hepatocytes established close and extensive contact with liver sinusoidal endothelial cells, thereby enhancing adenylyl cyclase–cAMP–PKA signalling in T cells. In these hepatic CD8 T cells, which recognize their antigen on hepatocytes, phosphorylation of key signalling kinases of the T cell receptor signalling pathway was impaired, which rendered them refractory to activation. Thus, close contact with liver sinusoidal endothelial cells curbs the activation and effector function of HBV-specific CD8 T cells that target hepatocytes expressing viral antigens by means of the adenylyl cyclase–cAMP–PKA axis in an immune rheostat-like fashion.

Fibrosing cholestatic hepatitis as a variant of the course of hepatotropic viruses’ infection

Fibrosing cholestatic hepatitis is a special variant of infectious hepatitis, with a rapid progressive deterioration of liver function, and usually results in immunosuppression. It has also been reported in patients with immunocompetent status having viral hepatitis B and C. Fibrosing cholestatic hepatitis is diagnosed based on the histological examination of the liver tissue, which reveals severe damage to hepatocytes with pronounced ballooning over a weak inflammatory reaction, pericellular and perisinusoidal fibrosis, and intracellular and tubular cholestases. Analysis of the literature confirms the authors’ assumption that pathological changes in the liver, described as fibrosing cholestatic hepatitis, can develop in different conditions under the influence of various infectious agents. Despite the availability of effective antiviral therapy for hepatitis B and C, the outcomes of fibrosing cholestatic hepatitis are often unfavorable, particularly in cases not associated with solid-organ transplantation. Currently, because of the emergence of numerous drugs that selectively act on the immune system and the development of new areas of medicine such as hematology, rheumatology, oncology, transplantology, and infectious diseases, doctors in these specialties increasingly encounter severe liver damage in patients receiving specific therapy. The authors believe that doctors who do not work at liver transplantation centers underestimate the possibility of fibrosing cholestatic hepatitis development in patients with viral hepatitis B and C, in the clinic of infectious and internal diseases.

Hepatic miR-149-5p upregulation fosters steatosis, inflammation and fibrosis development in mice and in human liver organoids

Background & aimsThe incidence of metabolic dysfunction – associated steatotic liver disease (MASLD) is increasing worldwide. Alterations of hepatic microRNA (miRNA) expression/activity significantly contribute to the development and progression of MASLD. Genetic polymorphisms of miR-149 are associated with an increased susceptibility to develop MASLD in humans. Aberrant expression of miR-149 was also associated with metabolic alterations in several organs, but the impact of hepatic miR-149-5p deregulation in MASLD remains poorly characterized. MethodsMiR-149-5p was downregulated in the liver of mice by in vivo transduction with hepatotropic adeno-associated virus 8 (AAV8) harboring shRNAs specific for miR-149-5p (shmiR149) or scrambled shRNAs (shCTL). MASLD was then induced in mice with a methionine/ choline deficient (MCD, n=7 per group) or a fructose, palmitate and cholesterol-enriched (FPC, n=8-12 per group, per protocol) diet. The impact of miR-149-5p modulation on MASLD development was assessed in vivo and in vitro using multi-lineage 3D human liver organoids (HLOs) and in Huh7 cells. ResultsMiR-149-5p expression was strongly upregulated in mouse liver from different models of MASLD (2-4 fold increase in ob/ob, db/db mice, high-fat and FPC fed mice). In vivo downregulation of miR-149-5p led to an amelioration of diet-induced hepatic steatosis, inflammation/fibrosis, and to increased whole-body fatty acid consumption. In HLOs, miR-149-5p overexpression promoted lipid accumulation, inflammation and fibrosis. In vitro analyses of human Huh7 cells overexpressing miR-149-5p indicated that glycolysis and intracellular lipid accumulation was promoted, while mitochondrial respiration was impaired. Translatomic analyses highlighted deregulation of multiple miR-149-5p potential targets in hepatocytes involved in MASLD development. ConclusionsMiR-149-5p upregulation contributes to MASLD development by affecting multiple metabolic/inflammatory/fibrotic pathways in hepatocytes. Our results further demonstrate that human liver organoids are a relevant 3D in vitro model to investigate hepatic steatosis and inflammation/fibrosis development. Impact and implicationsThis study delves into the escalating global concern of metabolic dysfunction-associated steatotic liver disease (MASLD). Our research shows compelling evidence that miR-149-5p plays a pivotal role in the disease's development and progression. By employing in vivo and innovative in vitro models using multi-lineage human liver organoids (HLOs), we demonstrate that miR-149-5p upregulation significantly impacts hepatocyte energy metabolism, exacerbating hepatic steatosis and inflammation/fibrosis by modulating a wide network of target genes. These findings not only shed light on the intricate miR-149-5p-dependent molecular mechanisms underlying MASLD, but also underscore the importance of HLOs as valuable 3D in vitro models for studying the disease's pathogenesis.

In Vitro Virucidal Activity of Different Essential Oils against Bovine Viral Diarrhea Virus Used as Surrogate of Human Hepatitis C Virus.

The hepatitis C virus (HCV) is a major hepatotropic virus that affects humans with increased risk of developing hepatocellular carcinoma. The bovine viral diarrhea virus (BVDV) causes abortion, calf mortality and poor reproductive performance in cattle. Due the difficulties of in vitro cultivation for HCV, BVDV has been used as surrogate for in vitro assessment of the efficacy of antivirals. Essential oils (EOs) display antiviral and virucidal activity on several viral pathogens. In this study, the virucidal activity of five EOs, Salvia officinalis L. EO (SEO), Melissa officinalis L. EO (MEO), Citrus lemon EO (LEO), Rosmarinus officinalis L. EO (REO) and Thymus vulgaris L. EO (TEO) against BVDV was evaluated in vitro at different concentrations for several time contacts. MEO and LEO were able to considerably inactivate BVDV with a time- and dose-dependent fashion. MEO and LEO at the highest concentrations decreased viral titer by 2.00 and 2.25 log10 TCID50/50 μL at 8 h contact time, respectively. SEO, REO and TEO displayed mild virucidal activity at the highest concentrations for 8 h contact times. In this study, the virucidal efficacies of MEO and LEO against BVDV were observed regardless of compound concentration and contact time. Further studies are needed to confirm the potential use of MEO and LEO as surface disinfectants.

Detection of Equine Parvovirus-Hepatitis Virus and Equine Hepacivirus in Archived Sera from Horses in France and Australia.

Reports of newly discovered equine hepatotropic flavi- and parvoviruses have emerged throughout the last decade in many countries, the discovery of which has stimulated a great deal of interest and clinical research. Although commonly detected in horses without signs of disease, equine parvovirus hepatitis (EqPV-H) and equine hepacivirus (EqHV) have been associated with liver disease, including following the administration of contaminated anti-toxin. Our aim was to determine whether EqPV-H and EqHV are present in Australian horses and whether EqPV-H was present in French horses and to examine sequence diversity between strains of both viruses amongst infected horses on either side of the globe. Sera from 188 Australian horses and 256 French horses from horses with and without clinical signs of disease were collected. Twelve out of 256 (4.7%) and 6 out of 188 (3.2%) French and Australian horses, respectively, were positive for the molecular detection of EqPV-H. Five out of 256 (1.9%) and 21 out of 188 (11.2%) French and Australian horses, respectively, were positive for the molecular detection of EqHV. Australian strains for both viruses were genomically clustered, in contrast to strains from French horses, which were more broadly distributed. The findings of this preliminary survey, with the molecular detection of EqHV and EqPV-H in Australia and the latter in France, adds to the growing body of awareness regarding these recently discovered hepatotropic viruses. It has provided valuable information not just in terms of geographic endemicity but will guide equine clinicians, carers, and authorities regarding infectious agents and potential impacts of allogenic tissue contamination. Although we have filled many gaps in the world map regarding equine hepatotropic viruses, further prospective studies in this emerging field may be useful in terms of elucidating risk factors and pathogenesis of these pathogens and management of cases in terms of prevention and diagnosis.

The role of inflammasome in chronic viral hepatitis.

Infections of hepatotropic viruses cause a wide array of liver diseases including acute hepatitis, chronic hepatitis and the consequently developed cirrhosis and hepatocellular carcinoma (HCC). Among the five classical hepatotropic viruses, hepatitis B virus (HBV) and hepatitis C virus (HCV) usually infect human persistently and cause chronic hepatitis, leading to major troubles to humanity. Previous studies have revealed that several types of inflammasomes are involved in the infections of HBV and HCV. Here, we summarize the current knowledge about their roles in hepatitis B and C. NLRP3 inflammasome can be activated and regulated by HBV and HCV. It is found to exert antiviral function or mediates inflammatory response in viral infections depending on different experimental models. Besides NLRP3 inflammasome, IFI16 and AIM2 inflammasomes participate in the pathological process of hepatitis B, and NALP3 inflammasome may sense HCV infection in hepatocytes. The inflammasomes affect the pathological process of viral hepatitis through its downstream secretion of inflammatory cytokines interleukin-1β (IL-1β) and IL-18 or induction of pyroptosis resulting from cleaved gasdermin D (GSDMD). However, the roles of inflammasomes in different stages of viral infection remains mainly unclear. More proper experimental models of viral hepatitis should be developed for specific studies in future, so that we can understand more about the complexity of inflammasome regulation and multifunction of inflammasomes and their downstream effectors during HBV and HCV infections.

Clinical problems and treatment of patients with chronic hepatitis C

Chronic viral hepatitis C is a chronic inflammatory disease lasting more than 6 months with predominant damage to liver tissue due to infection with the hepatitis C virus, which can lead to serious consequences: liver cirrhosis, liver cancer (hepatocellular carcinoma), and death. The etiological factor of this disease is a small hepatotropic RNA virus from the Flaviviridae family. Infection with the hepatitis C virus in a greater proportion of cases (55–85 %) leads to a chronic course of the disease, and over the next decades in about a quarter of patients, it leads to the development of liver cirrhosis, which, in turn, can serve as the basis for the formation of hepatocellular carcinoma.

Overview of acute liver failure in India.

Acute liver failure (ALF) is an infrequent, but serious complication subsequent to severe acute liver injury (sALI) due to various hepatotoxic agents such as hepatotropic virus(es) and drugs such as anti-tubercular medications, paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics and anti-cancer and anti-epileptic therapy and due to metabolic and autoimmune disease flares. ALF after sALI presents with encephalopathy associated with prolonged international normalized ratio (INR). Mortality in ALF is high and ranges between 50% and 80%. Due to severe liver damage, multiple sequels consequent to hepatic dysfunction result in complications such as hyperammonemia that culminates in encephalopathy associated with cerebral edema; innate immune paralysis resulting in increased frequency of infections and endotoxemia causing decrease in systemic vascular resistance (SVR) and tissue hypoperfusion and damage-associated molecular patterns (DAMPs) released from damaged hepatic parenchyma inducing pro-inflammatory cytokine storm, which may cause other organ dysfunctions. Certain etiologies such as hepatitis E virus and hepatitis A virus-related ALF or paracetamol-ALF (hyper-acute presentation) have better survival than remaining causes. In addition, if etiology-specific treatment (antivirals for ALF related to hepatitis B virus (HBV) or Herpes simplex virus (HSV) or N-acetylcysteine for paracetamol) is available, then the outcome with treatment is better. About half of the patients can be salvaged with medical therapy. All patients need intensive care and organ support to provide time for the liver to regenerate. Various prognostic models to predict high probability of mortality have been described, which should be used to select patient early during the disease for liver transplantation, which is associated with high long-term survival in these sick patients. The Indian National Association for Study of the Liver (INASL) recommends the ALF-Early Dynamic (ALFED) model as a preferred prognostic model in the Indian scenario, where hepatitis viruses are a dominant etiology of ALF and occur on a naïve liver with good regenerative capacity.

Bile acid-microbiota crosstalk in hepatitis B virus infection.

Hepatitis B virus (HBV) is a hepatotropic non-cytopathic virus characterized by liver-specific gene expression. HBV infection highjacks bile acid metabolism, notably impairing bile acid uptake via sodium taurocholate cotransporting polypeptide (NTCP), which is a functional receptor for HBV entry. Concurrently, HBV infection induces changes in bile acid synthesis and the size of the bile acid pool. Conversely, bile acid facilitates HBV replication and expression through the signaling molecule farnesoid X receptor (FXR), a nuclear receptor activated by bile acid. However, in HepaRG cells and primary hepatocytes, FXR agonists suppress HBV RNA expression and the synthesis and secretion of DNA. In the gut, the size and composition of the bile acid pool significantly influence the gut microbiota. In turn, the gut microbiota impacts bile acid metabolism and innate immunity, potentially promoting HBV clearance. Thus, the bile acid-gut microbiota axis represents a complex and evolving relationship in the context of HBV infection. This review explores the interplay between bile acid and gut microbiota in HBV infection and discusses the development of HBV entry inhibitors targeting NTCP.