Antiviral resistance and hepatitis B therapy

Molecular Epidemiology, Drug-Resistant Variants, and Therapeutic Implications of Hepatitis B Virus and Hepatitis D Virus Prevalence in Nigeria: A National Study

Information on circulating HBV (sub-)genotype, variants, and hepatitis D virus (HDV) coinfection, which vary by geographical area, is crucial for the efficient control and management of HBV. We investigated the genomic characteristics of HBV (with a prevalence of 8.1%) and the prevalence of HDV in Nigeria. We utilised 777 HBV-positive samples and epidemiological data from the two-stage sampled population-based, nationally representative Nigeria HIV/AIDS Indicator and Impact Survey conducted in 2018. We assessed 732 HBV DNA-extracted samples with detectable viral loads (VLs) for (sub-)genotypes and variants by whole-genome pre-amplification, nested PCR of the s-and pol-gene, and BigDye Terminator sequencing. We conducted HDV serology. In total, 19 out of the 36 + 1 states in Nigeria had a high prevalence of HBV (≥8%), with the highest prevalence (10.4%) in the north-central geopolitical zone. Up to 33.2% (95% CI 30.0-36.6) of the participants had detectable VLs of ≥300 copies/mL. The predominant circulating HBV genotype was E with 98.4% (95% CI 97.1-99.1), followed by A with 1.6% (95% CI 0.9-2.9). Drug-resistant associated variants and immune escape variants were detected in 9.3% and 0.4%, respectively. The seroprevalence of HDV was 7.34% (95% CI 5.5-9.2). Nigeria has subtype E as the major genotype with many variants.

Hepatitis B Virus Treatment in Children: Common Challenges and Management Options in a Case-Based Format

The management of hepatitis B virus (HBV) in pediatrics presents many challenges, given the potential sequelae of untreated infection including hepatic fibrosis, cirrhosis, and malignancy, and a lack of clear guidance on the timing of treatment initiation. The goal of this review is to feature common clinical scenarios that occur in the evaluation and treatment of HBV infection in children. Each vignette presents an opportunity to discuss guidelines and evidence-based practices as well as review landmark studies and evolving practices.

Risk of hepatitis B virus reactivation in cancer patients undergoing treatment with tyrosine kinase-inhibitors

This editorial commented on an article in the World Journal of Gastroenterology titled "Risks of Reactivation of Hepatitis B Virus in Oncological Patients Using Tyrosine Kinase-Inhibitors: Case Report and Literature Analysis" by Colapietro et al. In this editorial, we focused on providing a more comprehensive exploration of hepatitis B virus reactivation (HBVr) associated with the usage of tyrosine kinase inhibitors (TKIs). It includes insights into the mechanisms underlying HBV reactivation, the temporal relationship between TKIs and HBV reactivation, and preventive measures. The aim is to understand the need for nucleos(t)ide analogs (NAT) and serial blood tests for early recognition of reactivation and acute liver injury, along with management strategies. TKIs are considered to be an intermediate (1%-10%) of HBVr. Current guidelines stipulate that patients receiving therapy with high or moderate risks of reactivation or recent cancer diagnosis must have at least tested hepatitis B surface antigen, anti-hepatitis B core antigen (HBc), and anti-hepatitis B surface antibody. Anti-HBc screening in highly endemic areas means people with negative tests should be vaccinated against HBV. Nucleoside or nucleotide analogs (NAs) like entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF) form the basis of HBV reactivation prophylaxis and treatment during immunosuppression. Conversely, lamivudine, telbivudine, and adefovir are generally discouraged due to their reduced antiviral efficacy and higher risk of fostering drug-resistant viral strains. However, these less effective NAs may still be utilized in cases where ETV, TDF, and TAF are not feasible treatment options.

High Prevalence of Hepatitis B Virus Drug Resistance Mutations to Lamivudine among People with HIV/HBV Coinfection in Rural and Peri-Urban Communities in Botswana

(1) Background: We aimed to determine the prevalence of hepatitis B virus (HBV) resistance-associated mutations (RAMs) in people with HBV and human immunodeficiency virus (HBV/HIV) in Botswana. (2) Methods: We sequenced HBV deoxyribonucleic acid (DNA) from participants with HBV/HIV from the Botswana Combination Prevention Project study (2013-2018) using the Oxford Nanopore GridION platform. Consensus sequences were analyzed for genotypic and mutational profiles. (3) Results: Overall, 98 HBV sequences had evaluable reverse transcriptase region coverage. The median participant age was 43 years (IQR: 37, 49) and 66/98 (67.4%) were female. Most participants, i.e., 86/98 (87.8%) had suppressed HIV viral load (VL). HBV RAMs were identified in 61/98 (62.2%) participants. Most RAMs were in positions 204 (60.3%), 180 (50.5%), and 173 (33.3%), mostly associated with lamivudine resistance. The triple mutations rtM204V/L180M/V173L were the most predominant (17/61 [27.9%]). Most participants (96.7%) with RAMs were on antiretroviral therapy for a median duration of 7.5 years (IQR: 4.8, 10.5). Approximately 27.9% (17/61) of participants with RAMs had undetectable HBV VL, 50.8% (31/61) had VL < 2000 IU/mL, and 13/61 (21.3%) had VL ≥ 2000 IU/mL. (4) Conclusions: The high prevalence of lamivudine RAMs discourages the use of ART regimens with 3TC as the only HBV-active drug in people with HIV/HBV.

Antiviral effect of peptoids on hepatitis B virus infection in cell culture

Although antimicrobial peptides have been shown to inactivate viruses through disruption of their viral envelopes, clinical use of such peptides has been hampered by a number of factors, especially their enzymatically unstable structures. To overcome the shortcomings of antimicrobial peptides, peptoids (sequence-specific N-substituted glycine oligomers) mimicking antimicrobial peptides have been developed. We aimed to demonstrate the antiviral effects of antimicrobial peptoids against hepatitis B virus (HBV) in cell culture. The anti-HBV activity of antimicrobial peptoids was screened and evaluated in an infection system involving the HBV reporter virus and HepG2.2.15-derived HBV. By screening with the HBV reporter virus infection system, three (TM1, TM4, and TM19) of 12 peptoids were identified as reducing the infectivity of HBV, though they did not alter the production levels of HBs antigen in cell culture. These peptoids were not cytotoxic at the evaluated concentrations. Among these peptoids, TM19 was confirmed to reduce HBV infection most potently in a HepG2.2.15-derived HBV infection system that closely demonstrates authentic HBV infection. In cell culture, the most effective administration of TM19 was virus treatment at the infection step, but the reduction in HBV infectivity by pre-treatment or post-treatment of cells with TM19 was minimal. The disrupting effect of TM19 targeting infectious viral particles was clarified in iodixanol density gradient analysis. In conclusion, the peptoid TM19 was identified as a potent inhibitor of HBV. This peptoid prevents HBV infection by disrupting viral particles and is a candidate for a new class of anti-HBV reagents.

Entecavir: A Review and Considerations for Its Application in Oncology

Entecavir (ETV) is a drug used as a first-line treatment for chronic hepatitis B (CHB) virus infection because it is a guanosine nucleoside analogue with activity against the hepatitis B virus polymerase. The ETV dosage can range from 0.5 mg to 1 mg once a day and the most common side effects include headache, insomnia, fatigue, dizziness, somnolence, vomiting, diarrhea, nausea, dyspepsia, and increased liver enzyme levels. In addition to its conventional use, ETV acts as an inhibitor of lysine-specific demethylase 5B (KDM5B), an enzyme that is overexpressed in breast, lung, skin, liver, and prostate tumors and is involved in the hormonal response, stem cell regeneration, genomic stability, cell proliferation, and differentiation. The KDM5B enzyme acts as a transcriptional repressor in tumor suppressor genes, silencing them, and its overexpression leads to drug resistance in certain tumor types. Furthermore, the literature suggests that KDM5B activates the PI3K/AKT signaling pathway, while reducing KDM5B expression decreases AKT signaling, resulting in decreased tumor cell proliferation. In silico studies have demonstrated that ETV can inhibit tumor cell proliferation and induce apoptosis by reducing KDM5B expression. ETV also appears to inhibit PARP-1, has a high genetic barrier, reducing the chance of resistance development, and can also prevent the reactivation of the hepatitis B virus in cancer patients, which have proven to be significant advantages regarding its use as a repurposed drug in oncology. Therefore, ETV holds promise beyond its original therapeutic indication.

High Frequency of Antiviral Resistance Mutations in HBV Genotypes A2 and H: Multidrug Resistance Strains in Mexico

BACKGROUND AND AIMS

Lamivudine (3TC), telbivudine (LdT), entecavir (ETV), adefovir (ADF), and tenofovir (TFV) are drugs used to treat hepatitis B virus (HBV) infection, but specific mutations allow some viruses to become resistant to antiviral drugs or to acquire immune escape capacities. These mutations have not been thoroughly investigated in Mexico. This study aimed to estimate the prevalence of HBV antiviral resistance and escape mutations.

METHODS

This cross-sectional study analyzed 158 samples. HBV DNA was extracted, amplified, and sequenced in serum samples using the spin column method, PCR assay, and Sanger's sequencing, respectively. HBV genotypes were determined, and HBV mutations were tested using the Geno2pheno tool.

RESULTS

Overall, 68.4% (108/158) of HBV patients were infected with genotype H, followed by G (11.4%, 18/158), A2 (10.8%, 17/158), F1b (6.9.0%, 11/158), D (1.9%, 3/158), and E (0.6%, 1/158), and 5.1% (8/158) had evidence of recombination. The prevalence of resistance mutations was 8.2% (13/158) and the most common combined mutation was rt180M+rt204V. Notably, we found the combinations rt180M+rt204V+rt173L (n=2) and rt180M+rt204V+rt202G (n=1) that confer multidrug resistance to 3TC, LdT, and ETV. Resistance mutations were found in genotypes A2 (11.8%, 2/17), and H (10.2%, 11/108), and escape mutations were detected in HBV genotypes A2 (11.8%, 2/17), H (10.2%, 11/108), F1b (9.1%, 1/11) and G (5.6%, 1/18).

CONCLUSIONS

The highest prevalence of antiviral resistance mutations or escape mutations was detected in HBV genotypes A2 and H. The earliest cases of HBV multidrug resistance were detected in Mexico.

Phenolic Compounds in Salicornia spp. and Their Potential Therapeutic Effects on H1N1, HBV, HCV, and HIV: A Review

Despite public health risk mitigation measures and regulation efforts by many countries, regions, and sectors, viral outbreaks remind the world of our vulnerability to biological hazards and the importance of mitigation actions. The saltwater-tolerant plants in the Salicornia genus belonging to the Amaranthaceae family are widely recognized and researched as producers of clinically applicable phytochemicals. The plants in the Salicornia genus contain flavonoids, flavonoid glycosides, and hydroxycinnamic acids, including caffeic acid, ferulic acid, chlorogenic acid, apigenin, kaempferol, quercetin, isorhamnetin, myricetin, isoquercitrin, and myricitrin, which have all been shown to support the antiviral, virucidal, and symptom-suppressing activities. Their potential pharmacological usefulness as therapeutic medicine against viral infections has been suggested in many studies, where recent studies suggest these phenolic compounds may have pharmacological potential as therapeutic medicine against viral infections. This study reviews the antiviral effects, the mechanisms of action, and the potential as antiviral agents of the aforementioned phenolic compounds found in Salicornia spp. against an influenza A strain (H1N1), hepatitis B and C (HBV/HCV), and human immunodeficiency virus 1 (HIV-1), as no other literature has described these effects from the Salicornia genus at the time of publication. This review has the potential to have a significant societal impact by proposing the development of new antiviral nutraceuticals and pharmaceuticals derived from phenolic-rich formulations found in the edible Salicornia spp. These formulations could be utilized as a novel strategy by which to combat viral pandemics caused by H1N1, HBV, HCV, and HIV-1. The findings of this review indicate that isoquercitrin, myricetin, and myricitrin from Salicornia spp. have the potential to exhibit high efficiency in inhibiting viral infections. Myricetin exhibits inhibition of H1N1 plaque formation and reverse transcriptase, as well as integrase integration and cleavage. Isoquercitrin shows excellent neuraminidase inhibition. Myricitrin inhibits HIV-1 in infected cells. Extracts of biomass in the Salicornia genus could contribute to the development of more effective and efficient measures against viral infections and, ultimately, improve public health.

Ivermectin Inhibits HBV Entry into the Nucleus by Suppressing KPNA2

Hepatitis B virus (HBV) specifically infects human hepatocytes and increases the risks of cirrhosis and liver cancer. Currently, nucleic acid analogs are the main therapeutics for chronic hepatitis caused by HBV infection. Although nucleic acid analogs can eliminate HBV DNA by inhibiting HBV reverse transcriptase, they cannot lead to negative conversion of covalently closed circular DNA (cccDNA) and hepatitis B surface antigen (HBsAg). In this study, we revealed that the antifilarial drug ivermectin suppresses HBV production by a different mechanism from the nucleic acid analog entecavir or Na+ taurocholate co-transporting polypeptide-mediated entry inhibitor cyclosporin A. Ivermectin reduced the levels of several HBV markers, including HBsAg, in HBV-infected human hepatocellular carcinoma cells (HepG2-hNTCP-C4 cells) and humanized mouse hepatocytes (PXB hepatocytes). In addition, ivermectin significantly decreased the expression of HBV core protein and the nuclear transporter karyopherin α2 (KPNA2) in the nuclei of HepG2-hNTCP-C4 cells. Furthermore, depletion of KPNA1-6 suppressed the production of cccDNA. These results suggest that KPNA1-6 is involved in the nuclear import of HBV and that ivermectin suppresses the nuclear import of HBV by inhibiting KPNA2. This study demonstrates the potential of ivermectin as a novel treatment for hepatitis B.

Extrahepatic carcinogenicity of oral nucleos(t)ide analogues in chronic hepatitis B carriers: A 35,000-Korean outcome study

Evidence on the carcinogenicity of oral nucleos(t)ide analogues (NAs) is inconclusive and lacks data on the effects by chemical structure of the NAs in patients with chronic hepatitis B (CHB). We aimed to provide definitive results on this issue using a large set of CHB patients and data on all major NA drugs. The study population consisted of 10,331 patients with CHB receiving primary NA treatment for more than 6 months, and 24,836 untreated controls followed for at least as long as the treated patients. Using the inverse-probability-of-treatment-weighted (IPTW) method, the cumulative incidence of extrahepatic cancers was compared in the treated and untreated patients and across the cyclopentane, L-nucleoside and acyclic phosphonate categories of NAs. Analyses of individual cancers as sub-endpoints were also performed. The cumulative incidence of overall extrahepatic malignancies did not differ between the two groups in the IPTW cohort (hazard ratio [HR] 1.002; 95% confidence interval [CI] [0.859-1.169]). Similar statistical trends were observed in analyses across the three NA chemical subsets and controls. Per-cancer analyses indicated that NA treatment was significantly associated with increased risks of colorectal/anal cancers (HRs [95% CI], 1.538 [1.175-2.013]) and lymphoma (1.784 [1.196-2.662]). Conversely, breast cancer (HRs [95% CI], 0.669 [0.462-0.967]) and prostate cancer (0.521 [0.329-0.825]) were less prevalent in the NA-treated group. In conclusion, prolonged NA treatment presents carcinogenic risks for colorectal/anal and lymphoid tissues in CHB patients, although it does not affect most extrahepatic organs. The protective effect of NAs on breast and prostate cancers should be confirmed.

Emodin from Aloe inhibits Swine acute diarrhea syndrome coronavirus in cell culture

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is an emerging swine enteropathogenic coronavirus that causes severe diarrhea in neonatal piglets, leading to serious economic losses to the pig industries. At present, there are no effective control measures for SADS, making an urgent need to exploit effective antiviral therapies. Here, we confirmed that Aloe extract (Ae) can strongly inhibit SADS-CoV in Vero and IPI-FX cells in vitro. Furthermore, we detected that Emodin from Ae had anti-SADS-CoV activity in cells but did not impair SADS-CoV infectivity directly. The time-of-addition assay showed that Emodin inhibits SADS-CoV infection at the whole stages of the viral replication cycle. Notably, we found that Emodin can significantly reduce virus particles attaching to the cell surface and induce TLR3 (p < 0.001), IFN-λ3 (p < 0.01), and ISG15 (p < 0.01) expressions in IPI-FX cells, indicating that the anti-SADS-CoV activity of Emodin might be due to blocking viral attachment and the activation of TLR3-IFN-λ3-ISG15 signaling axis. These results suggest that Emodin has the potential value for the development of anti-SADS-CoV drugs.

Virological Treatment Monitoring for Chronic Hepatitis B

More than 250 million people worldwide are currently infected with hepatitis B, despite the effectiveness of vaccination and other preventive measures. In terms of treatment, new therapeutic approaches are rapidly developing, promising to achieve the elimination of infected cells and the complete cure of infection. The on-treatment monitoring of these innovative antiviral treatments will require the implementation of new virological tools. Therefore, new biomarkers are being evaluated besides the traditional virological and serological assays in order to obtain information on different steps of the viral replication cycle and to monitor response to therapy more accurately. The purpose of this work is to describe both standard and innovative tools for chronic hepatitis B treatment monitoring, and to analyse their potential and feasibility.

Na+-Taurocholate Co-Transporting Polypeptide (NTCP) in Livers, Function, Expression Regulation, and Potential in Hepatitis B Treatment

Chronic hepatitis B virus (HBV) infection has become one of the leading causes of liver cirrhosis and hepatocellular carcinoma globally. The discovery of sodium taurocholate co-transporting polypeptide (NTCP), a solute carrier, as a key receptor for HBV and hepatitis D virus (HDV) has opened new avenues for HBV treatment. Additionally, it has led researchers to generate hepatoma cell lines (including HepG2-NTCP and Huh-7-NTCP) susceptible to HBV infection in vitro, hence, paving the way to develop and efficiently screen new and novel anti-HBV drugs. This review summarizes the history, function and critical findings regarding NTCP as a viral receptor for HBV/HDV, and it also discusses recently developed drugs targeting NTCP.

Association and pharmacological synergism of the triple drug therapy baricitinib/remdesivir/rhACE2 for the management of COVID-19 infection

A massive vaccination campaign against the global COVID-19 pandemic caused by SARS-CoV-2 virus began worldwide in January 2021. However, studies continue to investigate the most effective and safe drug therapies to manage the various stages of viral infection. It is critical in the therapeutic management of the patient, with ongoing COVID-19 infection, to reduce viral load and replication, and to regulate the generalized hyperinflammatory state caused by the cytokine storm that occurs in the most severe phases. Probably the right drug therapy is represented by the use of different drugs acting in different modalities and on different targets, to avoid also viral drug resistance. In this article, we describe an interesting scientific pharmacological hypothesis arising from the evidence in the literature; we believe that the association of baricitinib/remdesivir/rhACE2, administered at the right time and dose, represents an important pharmacological synergism that can be therapeutically more effective for the treatment of COVID-19 infection than the single administration of drugs and avoid the phenomenon of drug resistance caused by the virus.

A new perspective on SARS-CoV-2 management

Baricitinib/remdesivir/rhACE2 may have an effective synergism of action

Avoiding viral drug resistance is of paramount importance

The effect of nucleos(t)ide analogues on clinical outcomes of patients treated with transarterial chemoembolization and radiofrequency ablation for hepatitis B virus-related hepatocellular carcinoma

Background/Aims

Because hepatitis B virus (HBV) replication has been known to play an important role in cancer recurrence after curative treatment of HBV-related hepatocellular carcinoma (HCC), we examined whether treatment based on nucleos(t)ide analogues (NAs) might decrease the recurrence rate and improve patient survival.

Methods

The retrospective cohort study enrolled 73 patients with chronic hepatitis B who were treated with transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) with curative intent for HCC. Among those, 30 and 43 patients were treated with tenofovir disoproxil fumarate (TDF) and entecavir (ETV), respectively.

Results

Of the 73 patients, 51 experienced HCC recurrence, and 14 patients were dead during a follow-up of 73±34 months. Multivariate analyses showed that tumor size (hazard ratio [HR], 1.590; 95% confidence-interval [CI], 1.106-2.285; P=0.012) and Child-Pugh class B (vs. class A/non cirrhosis; HR, 5.794; 95% CI, 2.311-14.523; P=0.001) was significantly associated with HCC recurrence, and Child-Pugh class B (HR, 7.357; 95% CI, 2.100-25.777; P=0.002) was an independent unfavorable prognostic factor for survival. During NAs therapy, TDF was superior to ETV for complete viral response at 1 year after the date of combination of TACE and RFA (P=0.016). However, the risks of HCC recurrence and survival were not significantly different between those treated with TDF versus ETV.

Conclusions

TDF was superior to ETV for achieving complete viral response. However, the recurrence and mortality after TACE and RFA for HBV-related HCC were not significantly different between patients treated with TDF versus ETV.

In vitro selection of Remdesivir resistance suggests evolutionary predictability of SARS-CoV-2

Remdesivir (RDV), a broadly acting nucleoside analogue, is the only FDA approved small molecule antiviral for the treatment of COVID-19 patients. To date, there are no reports identifying SARS-CoV-2 RDV resistance in patients, animal models or in vitro. Here, we selected drug-resistant viral populations by serially passaging SARS-CoV-2 in vitro in the presence of RDV. Using high throughput sequencing, we identified a single mutation in RNA-dependent RNA polymerase (NSP12) at a residue conserved among all coronaviruses in two independently evolved populations displaying decreased RDV sensitivity. Introduction of the NSP12 E802D mutation into our SARS-CoV-2 reverse genetics backbone confirmed its role in decreasing RDV sensitivity in vitro. Substitution of E802 did not affect viral replication or activity of an alternate nucleoside analogue (EIDD2801) but did affect virus fitness in a competition assay. Analysis of the globally circulating SARS-CoV-2 variants (>800,000 sequences) showed no evidence of widespread transmission of RDV-resistant mutants. Surprisingly, we observed an excess of substitutions in spike at corresponding sites identified in the emerging SARS-CoV-2 variants of concern (i.e., H69, E484, N501, H655) indicating that they can arise in vitro in the absence of immune selection. The identification and characterisation of a drug resistant signature within the SARS-CoV-2 genome has implications for clinical management and virus surveillance.

Amino Acid Polymorphism in Hepatitis B Virus Associated With Functional Cure

BACKGROUND & AIMS

To provide an adequate treatment strategy for chronic hepatitis B, it is essential to know which patients are expected to have a good prognosis and which patients do not require therapeutic intervention. Previously, we identified the substitution of isoleucine to leucine at amino acid 97 (I97L) in the hepatitis B core region as a key predictor among patients with stable hepatitis. In this study, we attempted to identify the point at which I97L affects the hepatitis B virus (HBV) life cycle and to elucidate the underlying mechanisms governing the stabilization of hepatitis.

METHODS

To confirm the clinical features of I97L, we used a cohort of hepatitis B e antigen-negative patients with chronic hepatitis B infected with HBV-I97 wild-type (wt) or HBV-I97L. The effects of I97L on viral characteristics were evaluated by in vitro HBV production and infection systems with the HBV reporter virus and cell culture-generated HBV.

RESULTS

The ratios of reduction in hepatitis B surface antigen and HBV DNA were higher in patients with HBV-I97L than in those with HBV-I97wt. HBV-I97L exhibited lower infectivity than HBV-I97wt in both infection systems with reporter HBV and cell culture-generated HBV. HBV-I97L virions exhibiting low infectivity primarily contained a single-stranded HBV genome. The lower efficiency of cccDNA synthesis was demonstrated after infection of HBV-I97L or transfection of the molecular clone of HBV-I97L.

CONCLUSIONS

The I97L substitution reduces the level of cccDNA through the generation of immature virions with single-stranded genomes. This I97L-associated low efficiency of cccDNA synthesis may be involved in the stabilization of hepatitis.

Antiviral therapeutics directed against RNA dependent RNA polymerases from positive-sense viruses

Viruses with positive-sense single stranded RNA (+ssRNA) genomes are responsible for different diseases and represent a global health problem. In addition to developing new vaccines that protect against severe illness on infection, it is imperative to identify new antiviral molecules to treat infected patients. The genome of these RNA viruses generally codes for an enzyme with RNA dependent RNA polymerase (RdRP) activity. This molecule is centrally involved in the duplication of the RNA genome. Inhibition of this enzyme by small molecules will prevent duplication of the RNA genome and thus reduce the viral titer. An overview of the different therapeutic strategies used to inhibit RdRPs from +ssRNA viruses is provided, along with an analysis of these enzymes to highlight new binding sites for inhibitors.

The relationship between integrin avß6 and HBV infection in patients with liver cirrhosis and hepatocellular carcinoma: a preliminary report

OBJECTIVE

the aim of this study was to investigate the expression of integrin αvβ6 in normal, hepatitis B, HBV-associated cirrhosis and HBV-associated HCC liver tissues.

METHODS

immunohistochemistry and real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) were used to study the expression of integrin αvβ6 in HBV-associated cirrhosis (n = 88), chronic hepatitis B ( n= 11), HBV-associated HCC (n = 84) and normal (n = 10) human liver tissues.

RESULTS

the expression of integrin αvβ6 was significantly upregulated in HBV-associated liver cirrhosis and the expression increased with an increase in severity of cirrhosis. Furthermore, it was moderately or weakly expressed in chronic hepatitis B and HBV-associated HCC liver tissues when compared to normal liver tissue.

CONCLUSION

integrin αvβ6 could be a predictive marker for the progression of liver cirrhosis associated with HBV infection. Further studies are needed to determine the association between the expression of integrin αvβ6 in hepatitis B and HBV-associated HCC liver tissues.

Antifungal resistance in Superficial mycoses

BACKGROUND AND OBJECTIVE

With the widespread use of antifungals to treat superficial mycoses, reports of antifungal resistance are increasing. Antifungal resistance is becoming a public health challenge and needs to be addressed in parallel with antibacterial and antiviral resistance.

METHODS

We review the growing resistance of fungal pathogens such as Trichophyton species and the emergence of novel pathogens, including multidrug-resistant strains in superficial mycoses. We also discuss the importance of laboratory diagnosis and antifungal susceptibility testing (AFST) in the management of recalcitrant infections.

RESULTS AND CONCLUSION

Antifungal resistance can occur naturally or develop over time when fungi are exposed to antifungals. The frequency of terbinafine-resistant Trichophyton isolates is increasing. Opportunistic pathogens such as Aspergillus and Candida species have developed resistance to classic azoles such as itraconazole and fluconazole, and the newer azoles such as posaconazole and voriconazole. Although uncommon, topical antifungals such as efinaconazole and tavaborole have shown to induce resistance in Trichophyton rubrum. The emergence of multidrug-resistant Trichophyton mentagrophytes/interdigitale, Candida auris, and Aspergillus species causing severe infections is highly concerning. Routine AFST should be considered to determine the most effective treatment, especially if there is failure to therapy. Combination treatment of oral and topical antifungals may be a consideration for managing recalcitrant infections.

Serum microRNAs predict response of patients with chronic hepatitis B to antiviral therapy

OBJECTIVES

To investigate the feasibility of using serum microRNAs to predict the response of chronic hepatitis B (CHB) patients to antiviral therapy over 48 weeks.

METHODS

Sixty-five CHB patients were divided into responder and non-responder groups according to whether hepatitis B e antigen seroconversion occurred at week 48. Serum microRNAs were dynamically detected.

RESULTS

At baseline, the responder group had lower miR-122-5p (P = 0.006) and higher miR-1307-3p (P = 0.018) than the non-responder group. After therapy, miR-320a-3p and miR-320c were higher in the responder group than the non-responder group (P = 0.043 and 0.031, respectively). In the responder group, 9 microRNAs-let-7d-5p, let-7f-5p, let-7i-5p, miR-126-3p, miR-1307-3p, miR-181a-5p, miR-21-5p, miR-425-5p and miR-652-3p-were significantly lower at week 48 than at baseline (P < 0.05); however, miR-320a-3p was significantly elevated after therapy (P < 0.001). In the non-responder group, miR-122-5p significantly decreased after therapy compared with baseline (P = 0.005). Finally, miR-122-5p was positively correlated with titer of hepatitis B virus DNA (r = 0.438, P = 0.008) and hepatitis B e antigen (r = 0.610, P < 0.001), and miR-320a-3p was negatively correlated with hepatitis B virus DNA titer (r = -0.366, P = 0.028) at baseline.

CONCLUSIONS

The dynamic fluctuations of serum microRNAs might predict the efficacy of antiviral therapy for CHB.

Shifting demographics and comorbidity burden in adult Chinese urban patients with chronic hepatitis B, 2013 and 2016

Chronic hepatitis B demographics and comorbidity data are limited in China. Materials & methods: The China Health Insurance Association claims database from 2013 and 2016 was used to augment the existing data: the proportion of patients aged >45 years increased significantly from 40.3% in 2013 to 49% in 2016 (p < 0.001). Results: Significant increases in multiple comorbidities were observed, including hypertension (9.4-14.5%), hyperlipidemia (4.7-7.0%) and cardiovascular disease (5.7-10%; p < 0.001 for all comparisons). Increases were observed in renal impairment (8.8-10.0%; p < 0.001) and osteoporosis and/or pathologic nontraumatic bone fracture (3.8-7.3%; p < 0.001). Conclusion: Careful selection of treatment options and comorbidity monitoring should be considered when managing adult Chinese patients with chronic hepatitis B.

Distinctive HBV Replication Capacity and Susceptibility to Tenofovir Induced by a Polymerase Point Mutation in Hepatoma Cell Lines and Primary Human Hepatocytes

Tenofovir disoproxil fumarate (TDF) has been regarded as the most potent drug for treating patients with chronic hepatitis B (CHB). However recently, viral mutations associated with tenofovir have been reported. Here, we found a CHB patient with suboptimal response after more than 4 years of TDF treatment. Clonal analysis of hepatitis B virus (HBV) isolated from sequential sera of this patient identified the seven previously reported TDF-resistant mutations (CYELMVI). Interestingly, a threonine to alanine mutation at the 301 amino acid position of the reverse-transcriptase (RT) domain, (rtT301A), was commonly accompanied with CYELMVI at a high rate (72.7%). Since the rtT301A mutation has not been reported yet, we investigated the role of this naturally occurring mutation on the viral replication and susceptibility to tenofovir in various liver cells (hepatoma cells as well as primary human hepatocytes). A cell-based phenotypic assay revealed that the rtT301A mutation dramatically impaired the replication ability with meaningful reduction in sensitivity to tenofovir in hepatoma cell lines. However, attenuated viral replication by the rtT301A mutation was significantly restored in primary human hepatocytes (PHHs). Our findings suggest that the replication capability and drug sensitivity of HBV is different between hepatoma cell lines and PHHs. Therefore, our study emphasizes that validation studies should be performed not only in the liver cancer cell lines but also in the PHHs to understand the exact viral fitness under antiviral pressure in patients.

Evidence for Use of Tenofovir in Pregnancy to Prevent Perinatal Transmission of Hepatitis B Infection

Perinatal transmission of hepatitis B virus continues to be a serious global public health concern. Transmission failures are related to high maternal viremia. Several antiviral therapies reduce maternal viremia around the time of delivery and decrease maternal-to-child-transmission. This chapter is a review of current studies that, ultimately, have provided strong evidence for the efficacy and safety of 3 antiviral drugs in pregnancy-lamivudine, telbivudine and tenofovir. The latter drug is the particular focus of this chapter which will show that tenofovir is the preferred antiviral therapy in pregnant women because of its potency, safety profile, and low risk of resistance.

Design, Synthesis and Bioactive Evaluation of Oxime Derivatives of Dehydrocholic Acid as Anti-Hepatitis B Virus Agents

Oxime derivatives of dehydrocholic acid and its esters were designed for anti-hepatitis B virus (HBV) drugs according to principles of assembling active chemical fragments. Twelve compounds were synthesized from dehydrocholic acid by esterification and oxime formation, and their anti-hepatitis B virus (HBV) activities were evaluated with HepG 2.2.15 cells. Results showed that 5 compounds exhibited more effective inhibition of HBeAg than positive control, among them 2b-3 and 2b-1 showed significant anti-HBV activities on inhibiting secretion of HBeAg (IC_{50 (2b-3)} = 49.39 ± 12.78 μM, SI _(2b-3) = 11.03; IC_{50 (2b-1)} = 96.64 ± 28.99 μM, SI _(2b-1) = 10.35) compared to the Entecavir (IC₅₀ = 161.24 μM, SI = 3.72). Molecular docking studies showed that most of these compounds interacted with protein residues of heparan sulfate proteoglycan (HSPG) in host hepatocyte and bile acid receptor.

Entecavir-resistant hepatitis B virus decreases surface antigenicity: A full genome and functional characterization

BACKGROUND AND AIM

Since polymerase and surface genes overlap in hepatitis B virus (HBV), an antiviral-induced mutation in the polymerase gene may alter the surface antigenicity in patients with chronic hepatitis B (CHB), but this possibility has not been clearly confirmed. This study aimed to determine the drug susceptibility and surface antigenicity of the patient-derived mutants.

PATIENTS AND METHODS

Full-length HBV genomes isolated from four entecavir-resistant CHB patients were cloned and sequenced. Around 10 clones of full-length HBV obtained from each patient were analysed and registered in the NCBI GenBank. Representative clones were further characterized by in vitro drug susceptibility and surface antigenicity assays.

RESULTS

The rtL180M + rtM204V mutations were common among all the clones analysed. Additionally, the ETV resistance mutations rtT184A/L, rtS202G and rtM250V were found among three patients. Most of the ETV-resistant mutants had amino acid alterations within the known epitopes recognized by T- and B-cells in the HBV surface and core antigens. The in vitro drug susceptibility assay showed that all tested clones were resistant to ETV treatment. However, they were all susceptible to ADV and TDF. More importantly, the rtI169T mutation in the RT domain, led to the sF161L mutation in the overlapping S gene, which decreased in surface antigenicity.

CONCLUSIONS

The ETV resistance mutations can affect the antigenicity of the HBsAg proteins due to changes in the overlapping sequence of this surface antigen. Thus, the apparent decline or disappearance of HBsAg needs to be interpreted cautiously in patients with previous or current antiviral resistance mutations.

Variability in the durability of CRISPR-Cas immunity

The durability of host resistance is challenged by the ability of pathogens to escape the defence of their hosts. Understanding the variability in the durability of host resistance is of paramount importance for designing more effective control strategies against infectious diseases. Here, we study the durability of various clustered regularly interspaced short palindromic repeats-Cas (CRISPR-Cas) alleles of the bacteria Streptococcus thermophilus against lytic phages. We found substantial variability in durability among different resistant bacteria. Since the escape of the phage is driven by a mutation in the phage sequence targeted by CRISPR-Cas, we explored the fitness costs associated with these escape mutations. We found that, on average, escape mutations decrease the fitness of the phage. Yet, the magnitude of this fitness cost does not predict the durability of CRISPR-Cas immunity. We contend that this variability in the durability of resistance may be because of variations in phage mutation rate or in the proportion of lethal mutations across the phage genome. These results have important implications on the coevolutionary dynamics between bacteria and phages and for the optimal deployment of resistance strategies against pathogens and pests. Understanding the durability of CRISPR-Cas immunity may also help develop more effective gene-drive strategies based on CRISPR-Cas9 technology. This article is part of a discussion meeting issue 'The ecology and evolution of prokaryotic CRISPR-Cas adaptive immune systems'.

Tenofovir monotherapy versus tenofovir plus entecavir combination therapy in HBeAg-positive chronic hepatitis patients with partial virological response to entecavir

AIMS

The aim of this retrospective study was to compare the efficacy and safety of tenofovir disoproxil fumarate (TDF) monotherapy and TDF + entecavir (ETV) combination therapy for chronic hepatitis B (CHB) patients with the partial virological response (PVR) to ETV.

METHODS

CHB patients with PVR to ETV were switched to TDF monotherapy or TDF + ETV combination therapy. The primary efficacy outcome was a virological response (VR), and the secondary efficacy outcomes were hepatitis B e antigen (HBeAg) seroconversion and alanine aminotransferase (ALT) normalization. The primary safety outcomes were changes in serum creatinine and serum phosphorus levels.

RESULTS

A total of 143 patients were investigated, including 63 patients in the TDF monotherapy group and 80 patients in the TDF + ETV combination therapy group. Baseline demographics and clinical characteristics were comparable between groups. The median age of patients was 44.5 years, and 76.2% of them were male. The VR rate in TDF + ETV group was higher than that of the TDF group at 48 weeks (88.8% vs 71.4%; P = .009). At 48 weeks, the HBeAg seroconversion rate of TDF + ETV group was higher than that of the TDF group (30% vs 15.9%; P = .049). There was no significant difference in the proportion of patients with elevated ALT in the TDF group and TDF + ETV group at 48 weeks (9.5% vs 7.5%; P = .665). After adjusting the treatment regimen, serum creatinine levels increased slightly and serum phosphorus level decreased slightly in both groups.

CONCLUSIONS

TDF + ETV combination therapy for 48 weeks had a higher VR rate than TDF monotherapy in CHB patients with PVR to ETV.

Coevolution analysis of amino-acids reveals diversified drug-resistance solutions in viral sequences: a case study of hepatitis B virus

The study of mutational landscapes of viral proteins is fundamental for the understanding of the mechanisms of cross-resistance to drugs and the design of effective therapeutic strategies based on several drugs. Antiviral therapy with nucleos(t)ide analogues targeting the hepatitis B virus (HBV) polymerase protein (Pol) can inhibit disease progression by suppression of HBV replication and makes it an important case study. In HBV, treatment may fail due to the emergence of drug-resistant mutants. Primary and compensatory mutations have been associated with lamivudine resistance, whereas more complex mutational patterns are responsible for resistance to other HBV antiviral drugs. So far, all known drug-resistance mutations are located in one of the four Pol domains, called reverse transcriptase. We demonstrate that sequence covariation identifies drug-resistance mutations in viral sequences. A new algorithmic strategy, BIS2TreeAnalyzer, is designed to apply the coevolution analysis method BIS2, successfully used in the past on small sets of conserved sequences, to large sets of evolutionary related sequences. When applied to HBV, BIS2TreeAnalyzer highlights diversified viral solutions by discovering thirty-seven positions coevolving with residues known to be associated with drug resistance and located on the four Pol domains. These results suggest a sequential mechanism of emergence for some mutational patterns. They reveal complex combinations of positions involved in HBV drug resistance and contribute with new information to the landscape of HBV evolutionary solutions. The computational approach is general and can be applied to other viral sequences when compensatory mutations are presumed.

A First-in-Human Trial of GLS4, a Novel Inhibitor of Hepatitis B Virus Capsid Assembly, following Single- and Multiple-Ascending-Oral-Dose Studies with or without Ritonavir in Healthy Adult Volunteers

GLS4 is a novel inhibitor of the hepatitis B virus (HBV) capsid assembly with inhibitory activities against nucleot(s)ide-resistant HBV strains. This study investigated the pharmacokinetics, safety, and tolerability of GLS4 and the effects of food and ritonavir in healthy adults. GLS4 was administered in a single-ascending-dose study over 1 to 240 mg and multiple-ascending-dose study that ranged from 30 mg once daily to 180 mg three times daily. The drug interaction study included sequential design (day 1 for 120 mg GLS4 alone, day 5 for 100 mg ritonavir alone, followed by 9 days of both drugs) and a placebo control (9 days of both 240 mg GLS4 and 100 mg ritonavir). The results showed that the steady-state trough concentration of multiple dosing of GLS4 alone was significantly lower than the 90% effective concentration of 55.7 ng/ml, even with increasing dosing frequency and dosage. An initial dose of 100 mg ritonavir significantly boosted plasma concentration at 24 h of 120 mg GLS4 from 2.40 to 49.8 ng/ml (geometric mean ratio, 20.7; 90% confidence interval, 17.0 to 25.3), while a milder effect was observed on the area under the curve from 0 to 24 h, with a 7.42-fold increase, and on the maximum concentration, with a 4.82-fold increase. The pharmacokinetics change in GLS4 persisted after 9 days of chronic dosing, with a trough concentration of 182 ng/ml. Both single and multiple doses of GLS4 up to 240 mg with or without ritonavir were well tolerated. These results support the investigation of a novel HBV treatment regimen containing GLS4 with 100 mg ritonavir added solely to enhance GLS4 concentrations in plasma. (This study was registered at the China Platform for Registry and Publicity of Drug Clinical Trials [http://www.chinadrugtrials.org.cn] under numbers CTR20132137 and CTR20150230.).

Low-dose anti-hepatitis B immunoglobulin regimen as prophylaxis for hepatitis B recurrence after liver transplantation

BACKGROUND

Combination of anti-hepatitis B immunoglobulin (HBIg) and antiviral nucleotide/nucleoside is the most common regimen for prophylaxis against hepatitis B virus (HBV) recurrence. However, what the optimal regimen is for HBIg administration remains subject to debate.

METHODS

Two hundred and thirty-two HBV patients who had liver transplantation were included in this study. According to the decline rate of HBIg, the patients were divided into quick (group Q, n = 95) and slow decline groups (group S, n = 137). Quick HBIg decline was defined as anti-HBs titer <200 IU/mL at postoperative month (POM) 1, when 24 000 IU of HBIg was given perioperatively. HBV recurrence was defined as reappearance of hepatitis B surface antigen (HBsAg).

RESULTS

After a mean (range) follow-up of 42.2 (24.1-76.8) months, the HBV recurrence rate was 12.1% for all 232 patients. The median (interquartile) HBIg titer was 96.2 (41.0-158.0) IU in group Q patients, compared to 418.0 (298.8-692.8) IU in group S patients at POM 1 (P < .001). For the patients in group Q, 18 patients (18.9%) had HBV recurrence; this was higher than the 10 (7.3%) patients in group S (P = .013). Multivariate analysis showed that quick HBIg decline and hepatocellular carcinoma recurrence were the risk factors for HBV recurrence.

CONCLUSION

Perioperative low-dose HBIg and antiviral nucleotide/nucleoside can effectively prevent HBV recurrence in patients with slow HBIg decline. For patients with quick HBIg decline, the idealized HBIg and antiviral agent regimen should be adjusted to establish an effective regimen as prophylaxis against HBV recurrence.

Mapping the Interactions of HBV cccDNA with Host Factors

Hepatitis B virus (HBV) infection is a major health problem affecting about 300 million people globally. Although successful administration of a prophylactic vaccine has reduced new infections, a cure for chronic hepatitis B (CHB) is still unavailable. Current anti-HBV therapies slow down disease progression but are not curative as they cannot eliminate or permanently silence HBV covalently closed circular DNA (cccDNA). The cccDNA minichromosome persists in the nuclei of infected hepatocytes where it forms the template for all viral transcription. Interactions between host factors and cccDNA are crucial for its formation, stability, and transcriptional activity. Here, we summarize the reported interactions between HBV cccDNA and various host factors and their implications on HBV replication. While the virus hijacks certain cellular processes to complete its life cycle, there are also host factors that restrict HBV infection. Therefore, we review both positive and negative regulation of HBV cccDNA by host factors and the use of small molecule drugs or sequence-specific nucleases to target these interactions or cccDNA directly. We also discuss several reporter-based surrogate systems that mimic cccDNA biology which can be used for drug library screening of cccDNA-targeting compounds as well as identification of cccDNA-related targets.

Antiviral treatment for treatment-naïve chronic hepatitis B: systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Chronic hepatitis B (CHB) infection poses a significant burden to public health worldwide. Most cases are clinically silent until late in the disease course. The main goal of current therapy is to improve survival and quality of life by preventing disease progression to cirrhosis and liver failure, and consequently hepatocellular carcinoma development. The objective of this review is to provide a contemporary and comprehensive evaluation of the effectiveness of treatment options.

METHODS

We performed a systematic review of peer-reviewed literature for randomized controlled trials involving treatment-naïve CHB adult population who received antiviral therapy. The endpoints were virologic response (VR), normalization of alanine aminotransferase (ALT norm), HBeAg loss, HBeAg seroconversion, and HBsAg loss for the HBeAg-positive population; and VR and ALT norm for the HBeAg-negative population. Network meta-analysis (NMA) was performed to synthesize evidence on the efficacy of treatment.

RESULTS

Forty-two publications were selected. Twenty-three evaluated HBeAg-positive population, 13 evaluated HBeAg-negative population, and six evaluated both. We applied NMA to the efficacy outcomes of the two populations separately. Treatment strategies were ranked by the probability of achieving outcomes, and pairwise comparisons calculated from NMA were reported in odds ratios (OR). For HBeAg-positive population, tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) were the best for VR; OR vs adefovir = 14.29, 95% CI 7.69-25 and 12.5, 95% CI 4.35-33.33 respectively. TAF was the best for achieving ALT norm (OR vs placebo = 12.5, 95% CI 4.55-33.33), HBeAg loss, and seroconversion (OR vs entecavir/TDF combination = 3.03, 95% CI 1.04-8.84 and 3.33, 95% CI 1.16-10 respectively). In the HBeAg-negative population, TDF and TAF were the best for VR (OR vs adefovir = 9.79, 95% CI 2.38-42.7 and 11.71, 95% CI 1.03-150.48 respectively). Telbivudine and TAF were the best for ALT norm. Certain nucleos(t)ide combinations also had high probability of achieving positive outcomes.

CONCLUSIONS

Our results are consonant with current clinical guidelines and other evidence reviews. For both HBeAg-positive and HBeAg-negative populations, TDF and TAF are the most effective agents for virologic suppression, and TAF is effective across all outcomes.

Long-term data on entecavir treatment for treatment-naive or lamivudine-resistant chronic hepatitis B infection in kidney transplant recipients

INTRODUCTION

Entecavir (ETV) showed short-term efficacy and safety in HBsAg-positive kidney transplant recipients (KTRs), but long-term data are lacking.

METHODOLOGY

We retrospectively reviewed 30 HBsAg-positive KTRs who received ETV during 2007-2017.

RESULTS

Eighteen treatment-naïve (Group I) and 12 lamivudine-resistant (Group II) patients received ETV for 48.4 ± 35.2 and 66.0 ± 26.0 months, respectively. Both groups show significant HBV DNA decline, but Group I achieved earlier undetectability after 11.9 ± 9.6 months (compared with 28.8 ± 24.2 months in Group II, P = .033). Group I showed higher rates of undetectable HBV DNA (89%, 94%, 94%, 100%, and 100% at 12, 24, 36, 48, and 60 months, respectively, compared with 25%, 50%, 50%, 91%, and 91% in Group II, P = .003). ALT normalized after 6.0 ± 1.9 and 6.8 ± 2.1 months in Group I and Group II, respectively. Four patients (33.3%) in Group II developed drug resistance (2 had persistent viraemia and 2 had virological breakthrough, at 40.3 ± 15.0 months). Group II showed higher liver stiffness after 5 years (7.7 ± 4.1 kPa, compared with 5.0 ± 1.6 kPa in Group I, P = .046) and incidence of cirrhosis (4 patients [33.3%], compared with 1 [5.6%] patient in Group I, P = .049). Two patients (one in each group) developed hepatocellular carcinoma. Renal allograft function remained stable during follow-up of 63.2 ± 33.4 months for both groups. There was no difference in patient and graft survival between two groups at 5 years (P = .62 and .36, respectively).

CONCLUSION

ETV showed favorable long-term efficacy and tolerability in treatment-naïve KTRs. One-third of lamivudine-resistant subjects showed non-response or viral breakthrough after ETV treatment.

Treatment Outcome and Renal Safety of 3-Year Tenofovir Disoproxil Fumarate Therapy in Chronic Hepatitis B Patients with Preserved Glomerular Filtration Rate

BACKGROUND/AIMS

To investigate the treatment efficacy and renal safety of long-term tenofovir disoproxil fumarate (TDF) therapy in chronic hepatitis B (CHB) patients with preserved renal function.

METHODS

The medical records of 919 CHB patients who were treated with TDF therapy were reviewed. All patients had preserved renal function with an estimated glomerular filtration rate (eGFR) of at least 60 mL/min/1.73 m².

RESULTS

A total of 426 patients (184 treatment-naïve and 242 treatment-experienced) were included for analysis. A virologic response (VR) was defined as achieving an undetectable serum hepatitis B virus (HBV) DNA level, and the overall VR was 74.9%, 86.7%, and 89.4% at the 1, 2, and 3-year follow-ups, respectively. Achieving a VR was not influenced by previous treatment experience, TDF combination therapy, or antiviral resistance. In a multivariate analysis, being hepatitis B e antigen positive at baseline and having a serum HBV DNA level ≥2,000 IU/mL at 12 months were associated with lower VR rates during the long-term TDF therapy. The overall renal impairment was 2.9%, 1.8%, and 1.7% at the 1, 2, and 3-year follow-ups, respectively. With regard to renal safety, underlying diabetes mellitus (DM) and an initial eGFR of 60 to 89 mL/min/1.73 m² were significant independent predictors of renal impairment.

CONCLUSIONS

TDF therapy appears to be an effective treatment option for CHB patients with a preserved GFR. However, patients with underlying DM and initial mild renal dysfunction (eGFR, 60 to 89 mL/min/1.73 m²) have an increased risk of renal impairment.

Preclinical Evaluation of In Vitro and In Vivo Antiviral Activities of KCT-01, a New Herbal Formula against Hepatitis B Virus

Hepatitis B virus (HBV) infectious diseases currently remain incurable due to limitations of conventional antivirals such as incapability of eradicating HBV DNA, prolonged use, drug resistance, and virological relapse. KCT-01, a 30% ethanol extract consisting of Artemisia capillaris, Sanguisorba officinalis, and Curcuma longa, was newly developed. The objective of this study was to investigate pharmacological activities of KCT-01 against HBV using HepG2.2.15 cells and a hydrodynamic injection model. KCT-01 significantly lowered antigen secretion, virion production, and pgRNA synthesis in HepG2.2.15 cells without affecting cell viability. KCT-01 administration also resulted in significant decrease of serum virion production, liver covalently closed circular (ccc) DNA levels, and mRNA synthesis of cytokines in the liver of mice injected with HBV DNA hydrodynamically. Interestingly, coadministration of KCT-01 with entecavir enhanced its in vitro and in vivo antiviral activities. Moreover, safety of KCT-01 was assured up to 5000 mg/kg in rats in both single and repeated-dose preclinical studies. Taken together, our findings demonstrate that KCT-01 is capable of suppressing HBV replication and inflammatory cytokine production in in vitro and in vivo models without showing toxicity, suggesting the potential of using KCT-01 alone or in combination with entecavir as antiviral agent.

Ideal Cure for Hepatitis B Infection: The Target is in Sight

Hepatitis B virus (HBV) is one of the most common causes of liver cirrhosis and hepatocellular carcinoma. Despite recent strides in pharmacotherapy, complete cure of HBV infection still remains an enigma. The biggest obstacle in HBV therapy is clearance of covalently closed circular deoxyribonucleic acid (cccDNA). We discuss about the role of cccDNA in HBV life cycle, efficacy and shortcomings of currently available antivirals as well as promising novel targets to achieve ideal HBV cure.

Development of tenofovir disoproxil fumarate resistance after complete viral suppression in a patient with treatment-naïve chronic hepatitis B: A case report and review of the literature

Tenofovir disoproxil fumarate (TDF) is a potent nucleotide analogue that is recommended as first-line therapy for patients with chronic hepatitis B. The results of a longitudinal study of TDF treatment demonstrated no development of resistance. We observed one treatment-naïve chronic hepatitis B (CHB) patient who developed TDF resistance after complete viral suppression during long-term TDF treatment. A 37-year-old HBeAg-positive man received TDF 300 mg/d for 43 mo. The hepatitis B virus (HBV) DNA titer was 8 log₁₀ copies/mL at baseline and became undetectable at 16 mo after treatment. However, the HBV DNA titer rebounded to 7.5 log₁₀ copies/mL at 43 mo after treatment. We performed full sequencing to find mutation sites associated with virologic breakthrough. The results showed 9 mutation sites, most of which had not been well-known as mutation sites. We changed the therapy from tenofovir to entecavir with a regimen of 0.5 mg once daily. After 4 mo, the HBV DNA titer decreased to 267 copies/mL, and the liver enzyme levels were normalized.

Pyrosequencing method for sensitive detection of HBV drug resistance mutations

Hepatitis B (HBV) drug resistance assay is important for guiding therapy after the development of virologic breakthrough for patients receiving nucleoside/-tide analog therapy. However, the existing genotyping tools are either costly or lack sensitivity to detect mixed genotypes, and an improved method of resistant mutation detection is needed. An assay protocol for clinical application using pyrosequencing method was developed, capable of detecting all known validated HBV polymerase gene mutations that impart resistance to lamivudine, adefovir, tenofovir, and entecavir. Sixty-eight serum samples with known HBV resistance genotypes, previously tested with either Sanger sequencing assay or commercial line probe assay, were used for validation. Where there were discrepancies between the two methods, clonal sequencing by Sanger's method was used for confirmation. The modified pyrosequencing method accurately identified all the cloned polymerase genotypes and was able to distinguish as little as 5% of the mutant populations. This assay can be performed on serum sample with HBV DNA as low as 13.5 IU/mL. The cost per test was less than existing commercial assay. HBV drug resistance pyrosequencing assay was accurate, more sensitive and cheaper compared with the existing methods. It can detect minor populations of drug-resistant clones earlier, before the drug resistant clones become dominant, allowing the opportunity for an earlier change of therapy.

Current concepts on immunopathogenesis of hepatitis B virus infection

Hepatitis B virus (HBV) infection is a leading cause of liver damage and hepatic inflammation. Upon infection, effective antiviral responses by CD8+ T cells, CD4+ T cells, Natural killer (NK) cells, and monocytes can lead to partial or complete eradication of the viral infection. To date, many studies have shown that the production of inhibitory cytokines such as Interleukin 10 (IL-10), Transforming growth factor beta (TGF-β), along with dysfunction of the dendritic cells (DCs), and the absence of efficient innate immune responses could lead to T cell exhaustion, development of persistent infection, and inability to eradicate the viral infection from liver. Understanding the immunopathogenesis of the virus could be useful in providing further insights toward novel strategies in the eradication of HBV infection.

Immune balance in Hepatitis B Infection: Present and Future Therapies

Chronic hepatitis B virus (HBV) infection affects millions of people worldwide and about half a million people die every year. India represents the second largest pool of chronic HBV infections with an estimated 40 million chronically infected patients. Persistence or clearance of HBV infection mainly depends upon host immune responses. Chronically infected individuals remain in immune tolerant phase unless HBV flares and leads to the development of chronic active hepatitis or acute-on-chronic liver failure. Strategies based on inhibition of viral replication (nucleoside analogues) or immune modulation (interferons) as monotherapy, or in combination in sequential therapies, are currently being used globally for reducing HBV viral load and mediating HBsAg clearance. However, the immune status and current therapies for promoting sustained virological responses in HBV-infected patients remain suboptimal. Elimination of cccDNA is major challenge for future therapies, and new molecules such as NTCP, Toll-like receptor (TLR)7 agonist (GS9620) and cyclophilin have emerged as potential targets for preventing HBV entry and replication. Other than these, HBV cccDNA elimination is the major target for future therapies.

Efficacy of tenofovir-based rescue therapy for chronic hepatitis B patients with resistance to lamivudine and entecavir

BACKGROUND/AIMS

Tenofovir disoproxil fumarate (TDF) monotherapy for 48 weeks provided a virological response comparable to that of TDF and entecavir (ETV) combination therapy in patients infected with ETV-resistant hepatitis B virus (HBV). Little long-term data in routine clinical practice are available regarding the optimal treatment of patients with ETV-resistant HBV.

METHODS

We investigated the long-term antiviral efficacy of combination therapy of TDF+lamivudine (LAM) or TDF+ETV compared to that of TDF monotherapy in 73 patients with resistance to both LAM and ETV.

RESULTS

Patients were treated with TDF monotherapy (n=12), TDF+LAM (n=19), or TDF+ETV (n=42) for more than 6 months. The median duration of TDF-based rescue therapy was 37 months. Virologic response (VR) was found in 63 patients (86.3%). The rates of VR among the three groups (TDF monotherapy, TDF+LAM, and TDF+ETV) were not statistically different (log-rank P=0.200) at 12 months (59.3%, 78.9%, and 51.8%, respectively) or at 24 months (88.4%, 94.7%, and 84.2%). In addition, treatment efficacy of TDF-based combination or TDF monotherapy was not statistically different with ETV-resistant strains or exposure to other antiviral agents. In multivariate analysis, only lower baseline HBV DNA level was an independent predictor for VR (hazard ratio, 0.723; 95% confidence interval, 0.627-0.834; P<0.001).

CONCLUSIONS

TDF monotherapy was as effective as combination therapy of TDF+LAM or TDF+ETV in maintaining long-term viral suppression in chronic hepatitis B patients with resistance to both LAM and ETV. HBV DNA level at the start of TDF rescue therapy was the only independent predictor of subsequent VR.

Systematic review with meta-analysis: the efficacy and safety of tenofovir to prevent mother-to-child transmission of hepatitis B virus

BACKGROUND

Preventing mother to child transmission of chronic hepatitis B infection in the setting of a high maternal viral load is challenging. The idea has emerged from antepartum tenofovir treatment with combination immunoprophylaxis.

AIMS

To demonstrate the efficacy and safety of tenofovir to prevent mother to child transmission of hepatitis B virus.

METHODS

PubMed, EMBASE, and Cochrane databases were searched through August 16, 2016. Comparative trials of second or third trimester tenofovir administration vs. controls for patients with chronic hepatitis B infection and non-comparative case series assessing mother to child transmission rates and evaluating maternal and foetal safety outcomes were included.

RESULTS

Ten studies (one randomised controlled trial, four non-randomised controlled trials and five case series) that enrolled 733 women were included. The pooled results from comparative trials (599 pregnancies) showed that tenofovir significantly reduced the risk of infant hepatitis B surface antigen seropositivity by 77% (odds ratio=0.23, 95% confidence intervals=0.10-0.52, P=.0004) without heterogeneity (I² =0%). In the case series analysis (134 pregnancies), only two cases (1.5%) of mother to child transmission with extremely high maternal viral load and non-compliance to treatment were identified. Maternal and foetal safety parameters including congenital malformation and foetal death were re-assuring.

CONCLUSIONS

For pregnant women with high hepatitis B virus DNA levels, tenofovir administration in the second or third trimester can prevent mother to child transmission when combined with hepatitis B immunoglobulin and the hepatitis B vaccine. Tenofovir is safe and tolerable for both the mother and foetus.

On-treatment HBV DNA dynamics predict virological breakthrough in entecavir-treated HBeAg-positive chronic hepatitis B

BACKGROUND & AIMS

Virological breakthrough (VBT) could be a manifestation of chronic hepatitis B (CHB) in patients treated with long-term nucleot(s)ide analogues. We aimed to determine the association of on-treatment serum hepatitis B virus (HBV) DNA with VBT in HBeAg-positive CHB patients receiving entecavir (ETV) treatment.

METHODS

A retrospective cohort study, including 162 consecutive patients (95 men and 67 women; mean age, 43.1±13.4 years) with HBeAg-positive CHB treated with ETV for at least 48 weeks between August 2008 and May 2015, was conducted. Univariate and multivariate cox regression analysis were used to identify associations with VBT and clinical factors, including HBV DNA and HBeAg serum status.

RESULTS

Among the 162 ETV-treated HBeAg-positive CHB patients, eighteen patients (11.1%) experienced VBT (VBT group), whereas the other 144 patients were without VBT (non-VBT group). The cumulative rate of HBV DNA < 100 IU/mL in the VBT group and the non-VBT group at week 48 were 44.44% and 70.14%, and at week 96 were 58.33% and 92.56%, respectively (p = 0.015). The cumulative rate of HBeAg seroclearance in the VBT group and non-VBT group at week 48 and week 96 were statistically significant (p = 0.014). Multivariate analysis disclosed that failure to achieve HBeAg seroclearance were the factors significantly associated with VBT.

CONCLUSIONS

Our results demonstrated that on-treatment HBV DNA could probably predict VBT in ETV-treated HBeAg-positive chronic hepatitis B patients. Failure to achieve HBeAg seroclearance was associated with VBT in ETV-treated HBeAg-positive CHB patients. HBV DNA >100IU/mL at 48 weeks is potentially a predictor for VBT.