Improvement of Gut Diversity and Composition after Direct-Acting Antivirals in HCV-Infected Patients with or without HIV Coinfection

BACKGROUND

The influence of direct-acting antivirals (DAAs) on the composition of gut microbiota in hepatitis C virus (HCV)-infected patients with or without human immunodeficiency virus (HIV) is unclear.

METHODS

We enrolled 62 patients with HCV monoinfection and 24 patients with HCV/HIV coinfection receiving elbasvir/grazoprevir from a clinical trial. Fecal specimens collected at pre-treatment and 12 weeks post-treatment were analyzed using amplicon-based 16S rRNA sequencing.

RESULTS

Sustained virological response (SVR12) rates in the mono- and co-infection groups were similar (98.4%vs.95.8%). Pre-treatment bacterial communities in the patient groups were less diverse and distinct from those of healthy controls. Compared with HCV-monoinfected patients, HCV/HIV-coinfected individuals showed comparable microbial alpha-diversity but displayed declined Firmicutes/Bacteroidetes ratio. The improvement of microbial dysbiosis was observed in responders achieving SVR12 across fibrosis stages but was not found in non-responders. Responders with low degree of fibrosis exhibited a recovery in alpha-diversity to level comparable with healthy controls. Reciprocal alterations of increased beneficial bacteria and reduced pathogenic bacteria were also observed in responders.

CONCLUSIONS

This study indicates short-term effect of DAAs in restoration of microbial dysbiosis. The favorable changes in gut microbiota profiles after viral eradication might potentially contribute towards the reduction of HCV-related complications among infected individuals.

Restoration of type I interferon signaling in intrahepatically primed CD8+ T cells promotes functional differentiation

Hepatitis B virus–specific (HBV-specific) CD8⁺ T cells fail to acquire effector functions after priming in the liver, but the molecular basis for the dysfunction is poorly understood. By comparing the gene expression profile of intrahepatically primed, dysfunctional HBV-specific CD8⁺ T cells with that of systemically primed, functional effector counterparts, we found that the expression of interferon-stimulated genes (ISGs) is selectively suppressed in the dysfunctional CD8⁺ T cells. The ISG suppression was associated with impaired phosphorylation of STAT1 in response to IFN-α treatment. Importantly, a strong induction of type I interferons (IFN-Is) in the liver facilitated the functional differentiation of intrahepatically primed HBV-specific CD8⁺ T cells in association with the restoration of ISGs’ expression in the T cells. These results suggest that intrahepatic priming suppresses IFN-I signaling in CD8⁺ T cells, which may contribute to the dysfunction. The data also suggest a therapeutic value of the robust induction of intrahepatic IFN-Is for the treatment of chronic HBV infection.

Functional defects of hepatitis B virus–specific CD8⁺ T cells correlate with impairment of type I interferon signaling after intrahepatic priming.

Murine neonatal ketogenesis preserves mitochondrial energetics by preventing protein hyperacetylation

Ketone bodies are generated in the liver and allow for the maintenance of systemic caloric and energy homeostasis during fasting and caloric restriction. It has previously been demonstrated that neonatal ketogenesis is activated independently of starvation. However, the role of ketogenesis during the perinatal period remains unclear. Here, we show that neonatal ketogenesis plays a protective role in mitochondrial function. We generated a mouse model of insufficient ketogenesis by disrupting the rate-limiting hydroxymethylglutaryl-CoA synthase 2 enzyme gene (Hmgcs2). Hmgcs2 knockout (KO) neonates develop microvesicular steatosis within a few days of birth. Electron microscopic analysis and metabolite profiling indicate a restricted energy production capacity and accumulation of acetyl-CoA in Hmgcs2 KO mice. Furthermore, acetylome analysis of Hmgcs2 KO cells revealed enhanced acetylation of mitochondrial proteins. These findings suggest that neonatal ketogenesis protects the energy-producing capacity of mitochondria by preventing the hyperacetylation of mitochondrial proteins.

Case of hepatitis B virus reactivation after ibrutinib therapy in which the patient remained negative for hepatitis B surface antigens throughout the clinical course

A 71-year-old man was diagnosed with B-cell chronic lymphocytic leukemia. He was negative for hepatitis B surface antigen (HBsAg), positive for antibodies against the hepatitis B surface and core, and negative for hepatitis B virus (HBV)-DNA before starting chemotherapy. A total of 13 months after the initiation of ibrutinib (a Bruton's tyrosine kinase inhibitor), the patient's alanine aminotransferase levels suddenly increased to 427 U/L. As the level of serum HBV-DNA increased to 5.2 logIU/mL, a diagnosis of HBV reactivation was made, whereas the patient remained negative for HBsAg. The patient's serum alanine aminotransferase levels normalized after the initiation of entecavir at a dose of 1 mg/day. However, it took >1 year to achieve an undetectable level of HBV-DNA, even with an add-on therapy of tenofovir disoproxil fumarate. Interestingly, the patient remained negative for HBsAg throughout the clinical course owing to triple HBsAg escape mutations: Q101K, M133L, and G145A.

Risk stratification for advanced colorectal neoplasia based on the findings of the index and first surveillance colonoscopies

Risk stratification by index colonoscopy is well established for first surveillance endoscopy, but whether the previous two colonoscopies affect the subsequent advanced neoplasias has not been established. Therefore, the subsequent risk based on the findings of the index and first surveillance colonoscopies were investigated. This retrospective, cohort study was conducted in two clinics and included participants who had undergone two or more colonoscopies after index colonoscopy. High-risk was defined as advanced adenoma (≥ 1 cm, or tubulovillous or villous histology, or high-grade dysplasia). Based on the findings of the index and first surveillance colonoscopies, patients were classified into four categories: category A (both colonoscopy findings were normal), category B (no high-risk findings both times), category C (one time high-risk finding), and category D (high-risk findings both times). The incidence of subsequent advanced neoplasia was examined in each category. A total of 13,426 subjects were included and surveyed during the study periods. The subjects in category D had the highest risk of advanced neoplasia (27.4%, n = 32/117). The subjects in category A had the lowest risk (4.0%, n = 225/5,583). The hazard ratio for advanced neoplasia of category D compared to category A was 9.90 (95% Confidence interval 6.82-14.35, P<0.001). Classification based on the findings of index and first surveillance colonoscopies more effectively stratifies the risk of subsequent advanced neoplasia, resulting in more proper allocation of colonoscopy resources after two consecutive colonoscopies.

Analysis of Hepatitis B Virus Genotype D in Greenland Suggests the Presence of a Novel Quasi-Subgenotype

A disproportionate number of Greenland's Inuit population are chronically infected with Hepatitis B virus (HBV; 5-10%). HBV genotypes B and D are most prevalent in the circumpolar Arctic. Here, we report 39 novel HBV/D sequences from individuals residing in southwestern Greenland. We performed phylodynamic analyses with ancient HBV DNA calibrators to investigate the origin and relationship of these taxa to other HBV sequences. We inferred a substitution rate of 1.4 × 10-5 [95% HPD 8.8 × 10-6, 2.0 × 10-5] and a time to the most recent common ancestor of 629 CE [95% HPD 37-1138 CE]. The Greenland taxa form a sister clade to HBV/D2 sequences, specifically New Caledonian and Indigenous Taiwanese sequences. The Greenland sequences share amino acid signatures with subgenotypes D1 and D2 and ~97% sequence identity. Our results suggest the classification of these novel sequences does not fit within the current nomenclature. Thus, we propose these taxa be considered a novel quasi-subgenotype.

Impact of long-term antiretroviral therapy on gut and oral microbiotas in HIV-1-infected patients

In HIV-1-infected patients, antiretroviral therapy (ART) is a key factor that may impact commensal microbiota and cause the emergence of side effects. However, it is not fully understood how long-term ART regimens have diverse impacts on the microbial compositions over time. Here, we performed 16S ribosomal RNA gene sequencing of the fecal and salivary microbiomes in patients under different long-term ART. We found that ART, especially conventional nucleotide/nucleoside reverse transcriptase inhibitor (NRTI)-based ART, has remarkable impacts on fecal microbial diversity: decreased α-diversity and increased ß-diversity over time. In contrast, dynamic diversity changes in the salivary microbiome were not observed. Comparative analysis of bacterial genus compositions showed a propensity for Prevotella-enriched and Bacteroides-poor gut microbiotas in patients with ART over time. In addition, we observed a gradual reduction in Bacteroides but drastic increases in Succinivibrio and/or Megasphaera under conventional ART. These results suggest that ART, especially NRTI-based ART, has more suppressive impacts on microbiota composition and diversity in the gut than in the mouth, which potentially causes intestinal dysbiosis in patients. Therefore, NRTI-sparing ART, especially integrase strand transfer inhibitor (INSTI)- and/or non-nucleotide reverse transcriptase inhibitor (NNRTI)-containing regimens, might alleviate the burden of intestinal dysbiosis in HIV-1-infected patients under long-term ART.

Transition rates to cirrhosis and liver cancer by age, gender, disease and treatment status in Asian chronic hepatitis B patients

BACKGROUND

Increasing hepatitis-related mortality has reignited interest to fulfill the World Health Organization's goal of viral hepatitis elimination by 2030. However, economic barriers have enabled only 28% of countries to implement countermeasures. Given the high disease burden among Asians, we aimed to present age, sex, disease activity and treatment-specific annual progression rates among Asian chronic hepatitis B (CHB) patients to inform health economic modeling efforts and cost-effective public health interventions.

METHODS

We analyzed 18,056 CHB patients from 36 centers across the U.S. and seven countries/regions of Asia Pacific (9530 treated; 8526 untreated). We used Kaplan-Meier methods to estimate annual incidence of cirrhosis and hepatocellular carcinoma (HCC). Active disease was defined by meeting the APASL treatment guideline criteria.

RESULTS

Over a median follow-up of 8.55 years, there were 1178 incidences of cirrhosis and 1212 incidences of HCC (297 without cirrhosis, 915 with cirrhosis). Among the 8526 untreated patients (7977 inactive, 549 active), the annual cirrhosis and HCC incidence ranged from 0.26% to 1.30% and 0.04% to 3.80% in inactive patients, and 0.55 to 4.05% and 0.19 to 6.03% in active patients, respectively. Of the 9530 treated patients, the annual HCC rates ranged 0.03-1.57% among noncirrhotic males and 2.57-6.93% among cirrhotic males, with lower rates for females. Generally, transition rates increased with age, male sex, the presence of fibrosis/cirrhosis, and active disease and/or antiviral treatment.

CONCLUSION

Using data from a large and diverse real-world cohort of Asian CHB patients, the study provided detailed annual transition rates to inform practice, research and public health planning.

Hepatitis B Core-Related Antigen to Indicate High Viral Load: Systematic Review and Meta-Analysis of 10,397 Individual Participants

BACKGROUND & AIMS

To eliminate hepatitis B virus (HBV) infection, scale-up of testing and treatment in resource-limited countries is crucial. However, access to nucleic acid testing to quantify HBV DNA, an essential test to examine treatment eligibility, remains severely limited. We assessed the performance of a novel immunoassay, HBV core-related antigen (HBcrAg), as a low-cost (less than US $15/assay) alternative to nucleic acid testing to indicate clinically important high viremia in chronic HBV patients infected with different genotypes.

METHODS

We searched Medline, Embase, Scopus, and Web of Science databases through June 27, 2018. Three reviewers independently selected studies measuring HBV DNA and HBcrAg in the same blood samples. We contacted authors to provide individual participant data (IPD). We randomly allocated each IPD to a derivation or validation cohort. We applied optimal HBcrAg cut-off values derived from the derivation set to the validation set to estimate sensitivity/specificity.

RESULTS

Of 74 eligible studies, IPD were obtained successfully for 60 studies (81%). Meta-analysis included 5591 IPD without antiviral therapy and 4806 treated with antivirals. In untreated patients, the pooled area under the receiver operating characteristic curve and optimal cut-off values were as follows: 0.88 (95% CI, 0.83-0.94) and 3.6 log U/mL to diagnose HBV DNA level of 2000 IU/mL or greater; and 0.96 (95% CI, 0.94-0.98) and 5.3 log U/mL for 200,000 IU/mL or greater, respectively. In the validation set, the sensitivity and specificity were 85.2% and 84.7% to diagnose HBV DNA level of 2000 IU/mL or greater, and 91.8% and 90.5% for 200,000 IU/mL or greater, respectively. The performance did not vary by HBV genotypes. In patients treated with anti-HBV therapy the correlation between HBcrAg and HBV DNA was poor.

CONCLUSIONS

HBcrAg might be a useful serologic marker to indicate clinically important high viremia in treatment-naïve, HBV-infected patients.

Reduction of T-Box 15 gene expression in tumor tissue is a prognostic biomarker for patients with hepatocellular carcinoma

Genome-wide analysis is widely applied to detect molecular alterations during oncogenesis and tumor progression. We analyzed DNA methylation profiles of hepatocellular carcinoma (HCC), and investigated the clinical role of most heypermethylated of tumor, encodes T-box 15 (TBX15), which was originally involved in mesodermal differentiation. We conducted a genome-wide analysis of DNA methylation of tumor and non-tumor tissue of 15 patients with HCC, and revealed TBX15 was the most hypermethylated gene of tumor (Beta-value in tumor tissue = 0.52 compared with non-tumor tissue). Another validation set, which comprised 58 HCC with radical resection, was analyzed to investigate the relationships between tumor phenotype and TBX15 mRNA expression. TBX15 mRNA levels in tumor tissues were significantly lower compared with those of nontumor tissues (p < 0.0001). When we assigned a cutoff value = 0.5-fold, the overall survival 5-year survival rates of the low-expression group (n = 17) were significantly shorter compared with those of the high-expression group (n = 41) (43.3% vs. 86.2%, p = 0.001). Multivariate analysis identified low TBX15 expression as an independent prognostic factor for overall and disease-free survival. Therefore, genome-wide DNA methylation profiling indicates that hypermethylation and reduced expression of TBX15 in tumor tissue represents a potential biomarker for predicting poor survival of patients with HCC.

Establishment of a novel hepatitis B virus culture system using immortalized human hepatocytes

Recent development of hepatitis B virus (HBV) culture systems has made it possible to analyze the almost all steps of the viral life cycle. However, the reproducibility of interaction between HBV and host cells seemed inaccurate in those systems because of utilization of cancer cell lines with a difference from hepatocytes in the majority of cases. In this study, in order to resolve this point, a novel HBV culture system using non-cancer-derived immortalized human hepatocytes derived cell lines, producing exogenous human sodium taurocholate cotransporting polypeptide, was developed. One of the cell clones, E/NtG8 cells, was permissive to both blood-borne HBV (HBVbb) and culture-derived recombinant HBV when cultured in the three-dimensional condition. Furthermore, the production of infectious HBV particles, which showed the similar physicochemical properties to HBVbb, was observed for about a month after HBVbb infection in this system, suggesting that it may reproduce whole steps of the HBV lifecycle under the condition analogous to human liver cells infected with HBV. This system seemed to contribute not only to find novel interactions between HBV and host cells but also to understand mechanism of HBV pathogenesis.

HCC risk post-SVR with DAAs in East Asians: findings from the REAL-C cohort

BACKGROUND

Despite HCV cure, patients remain at risk for HCC, but risk factor data for HCC following SVR are limited for Asian patients.

METHODS

To address this gap, we analyzed 5814 patients (5646 SVR, 168 non-SVR) from the Real-World Evidence from the Asia Liver Consortium for HCV (REAL-C) who did not have HCC or a history of HCC at baseline (pre-DAA treatment) and did not develop HCC within 6 months of baseline. To assess the effect of SVR on HCC incidence, we used 1:4 propensity score matching [(PSM), age, sex, baseline cirrhosis, and baseline AFP] to balance the SVR and non-SVR groups.

RESULTS

In the PSM cohort (160 non-SVR and 612 SVR), the HCC incidence rate per 100 person years was higher in the non-SVR compared to the SVR group (5.26 vs. 1.94, p < 0.001). Achieving SVR was independently associated with decreased HCC risk (adjusted HR [aHR]: 0.41, p = 0.002). Next, we stratified the SVR cohort of 5646 patients to cirrhotic and noncirrhotic subgroups. Among cirrhotic SVR patients, aged ≥ 60, having an albumin bilirubin grade (ALBI) of 2 or 3 (aHR: 2.5, p < 0.001), and baseline AFP ≥ 10 ng/mL (aHR: 1.6, p = 0.001) were associated with higher HCC risk, while among the non-cirrhotic SVR group, only baseline AFP ≥ 10 ng/mL was significant (aHR: 4.26, p = 0.005).

CONCLUSIONS

Achieving SVR decreases HCC risk; however, among East Asians, patients with elevated pretreatment AFP remained at risk. Pretreatment AFP, an easily obtained serum marker, may provide both prognostic and surveillance value for HCC in East Asian patients who obtained SVR.

Hepatitis B surface antigen, core-related antigen and HBV RNA: Predicting clinical relapse after NA therapy discontinuation

BACKGROUND & AIMS

The safe discontinuation of nucleos(t)ide analogue therapy remains challenging in chronic hepatitis B. We investigated the potential role of quantitative hepatitis B surface antigen, hepatitis B core-related antigen and hepatitis B virus RNA at the end of treatment in predicting off-therapy relapse.

METHODS

Patients who fulfilled the stopping criteria of the Asian Pacific Association for the Study of the Liver guideline were enrolled. Virological relapse was defined as hepatitis B virus DNA level greater than 2000 IU/mL, and clinical relapse was defined as virological relapse plus alanine aminotransferase level of more than twice the upper limit of normal.

RESULTS

Ninety-two patients participated. The combination of end-of-treatment hepatitis B core-related antigen and hepatitis B virus RNA levels was most predictive of clinical relapse. Multivariate analysis revealed that end-of-treatment hepatitis B core-related antigen and hepatitis B virus RNA were independently associated with clinical relapse. During follow-up, no patients with undetectable hepatitis B core-related antigen (<3.0 log₁₀ U/mL) and hepatitis B virusRNA (<2.0 log₁₀ copies/mL) at end of treatment developed clinical relapse, in comparison with 22.9% and 62.5% patients with detectable levels of one or both biomarkers respectively. End-of-treatment quantitative hepatitis B surface antigen was linked to a likelihood of hepatitis B surface antigen clearance.

CONCLUSIONS

The combined hepatitis B core-related antigen and hepatitis B virus RNA assays at end of treatment were highly predictive of subsequent clinical relapse. These novel biomarkers could potentially be used to identify patients who could safely discontinue nucleos(t)ide analogue therapy.

Development of an in vivo delivery system for CRISPR/Cas9-mediated targeting of hepatitis B virus cccDNA

Chronic hepatitis B virus (HBV) infection constitutes a global health issue with limited current therapeutic efficacy owing to the persistence of viral episomal DNA (cccDNA). The CRISPR/Cas9 system, a newly developed, powerful tool for genome editing and potential gene therapy, requires efficient delivery of CRISPR components for successful therapeutic application. Here, we investigated the effects of lentiviral- or adeno-associated virus 2 (AAV2) vector-mediated delivery of 3 guide (g)RNAs/Cas9 selected from 16 gRNAs. These significantly suppressed HBV replication in cells, with WJ11/Cas9 exhibiting highest efficacy and chosen for in vivo study. AAV2/WJ11-Cas9 also significantly inhibited HBV replication and significantly reduced cccDNA in the tested cells. Moreover, AAV2/WJ11-Cas9 enhanced entecavir effects when used in combination, indicative of different modes of action. Notably, in humanized chimeric mice, AAV2/WJ11-Cas9 significantly suppressed HBcAg, HBsAg, and HBV DNA along with cccDNA in the liver tissues without significant cytotoxicity; accordingly, next generation sequencing data showed no significant genomic mutations. To our knowledge, this represents the first evaluation of the CRISPR/Cas9 system using an HBV natural infection mode. Therefore, WJ11/Cas9 delivered by comparatively safer AAV2 vectors may provide a new therapeutic strategy for eliminating HBV infection and serve as an effective platform for curing chronic HBV infection.

Loss of skeletal muscle mass affects the incidence of minimal hepatic encephalopathy: a case control study

Background

Sarcopenia is a syndrome characterized by progressive and systemic decreases in skeletal muscle mass and muscle strength. The influence or prognosis of various liver diseases in this condition have been widely investigated, but little is known about whether sarcopenia and/or muscle mass loss are related to minimal hepatic encephalopathy (MHE).

Methods

To clarify the relationship between MHE and sarcopenia and/or muscle mass loss in patients with liver cirrhosis.

Methods

Ninety-nine patients with liver cirrhosis were enrolled. MHE was diagnosed by a neuropsychiatric test. Skeletal mass index (SMI) and Psoas muscle index (PMI) were calculated by dividing skeletal muscle area and psoas muscle area at the third lumbar vertebra by the square of height in meters, respectively, to evaluate muscle volume.

Results

This study enrolled 99 patients (61 males, 38 females). MHE was detected in 48 cases (48.5%) and sarcopenia in 6 cases (6.1%). Patients were divided into two groups, with or without MHE. Comparing groups, no significant differences were seen in serum ammonia concentration or rate of sarcopenia. SMI was smaller in patients with MHE (46.4 cm²/m²) than in those without (51.2 cm²/m², P = 0.027). Similarly, PMI was smaller in patients with MHE (4.24 cm²/m²) than in those without (5.53 cm²/m², P = 0.003). Skeletal muscle volume, which is represented by SMI or PMI was a predictive factor related to MHE (SMI ≥ 50 cm²/m²; odds ratio 0.300, P = 0.002, PMI ≥ 4.3 cm²/m²; odds ratio 0.192, P = 0.001).

Conclusions

Muscle mass loss was related to minimal hepatic encephalopathy, although sarcopenia was not. Measurement of muscle mass loss might be useful to predict MHE.

East Asia expert opinion on treatment initiation for chronic hepatitis B

BACKGROUND

Globally, chronic hepatitis B (CHB) is a major public health concern. Timely and effective management can prevent disease progression to cirrhosis and reduce the risk of hepatocellular carcinoma (HCC). Currently, there is no consensus on the clinical management of CHB in East Asia.

AIM

To establish an East Asia expert opinion on treatment initiation for CHB based on alanine aminotransferase (ALT) level, hepatitis B virus (HBV) deoxyribonucleic acid (DNA) level, cirrhosis and HCC risk scores.

METHODS

A meeting was held online with a panel of 10 experts from East Asia to discuss ALT, HBV DNA, cirrhosis and HCC risk scores. Indications for CHB treatment in the latest international guidelines were reviewed. Consensus was summarised to provide recommendations on the initiation of treatment for CHB.

RESULTS

Anti-viral therapy is recommended for CHB patients with (a) HBV DNA ≥ 2000 IU/mL and ALT ≥ 1× upper limit of normal (ULN); (b) HBV DNA ≥ 2000 IU/mL, ALT < 1× ULN and ≥ F2 fibrosis and/or ≥ A2 necroinflammation occurs; (c) cirrhosis and detectable HBV DNA; or (d) HBV DNA ≥ 2000 IU/mL, ALT < 1× ULN and a family history of cirrhosis or HCC, extrahepatic manifestations or age > 40 years. Patients with cirrhosis and/or HCC should be treated regardless of ALT levels if HBV DNA level is detectable. Initiating anti-viral therapy or close monitoring at 3-month intervals is recommended for CHB patients with at least two HCC risk factors.

CONCLUSIONS

These expert recommendations will contribute to a new standard of daily clinical practice in East Asia.

Free energy profile of permeation of Entecavir through Hepatitis B virus capsid studied by molecular dynamics calculation

Entecavir, triphosphorylated in liver cells, is an antiviral reagent against Hepatitis B virus (HBV). The reagent inhibits reverse transcription of RNA inside the virus capsid. In the present study, free energy profile of an Entecavir triphosphate (ETVTP) molecule has been calculated when it passes through pores of the capsid along two- and three-fold rotational symmetry axes in order to investigate permeation pathway of the reagent to the inside of the capsid. The calculations have been done based on thermodynamic integration (TI) method combined with all-atomistic molecular dynamic (MD) calculations. A free energy minimum of −19 kJ/mol was found at the entrance of the pore from the outside along the three-fold symmetry axis. This stabilization is from the interaction of negatively charged ETVTP with positively charged capsid methionine residues. This excess free energy concentrates of the reagent at the entrance of the pore by a factor of about 2000. A free energy barrier of approximately 13 kJ/mol was also found near the exit of the pore to the inside of the capsid due to narrow space of the pore surrounded by hydrophobic wall made by proline residues and negatively charged wall by aspartic acid residues. There, ETVTP is partially dehydrated in order to pass through the narrow space, which causes the great free energy loss. Further, the negatively charged residues produce repulsive forces on the ETVTP molecule. In contrast, in the case of the pore along the two-fold symmetry axis, the calculated free energy profile showed shallower free energy minimum, −4 kJ/mol at the entrance in spite of the similarly high barrier, 7 kJ/mol, near the exit of the pore.

Screening siRNAs against host glycosylation pathways to develop novel antiviral agents against hepatitis B virus

AIM

Hepatitis B virus (HBV) relies on glycosylation for crucial functions, such as entry into host cells, proteolytic processing and protein trafficking. The aim of this study was to identify candidate molecules for the development of novel antiviral agents against HBV using an siRNA screening system targeting the host glycosylation pathway.

METHODS

HepG2.2.15.7 cells that consistently produce HBV were employed for our in vitro study. We investigated the effects of siRNAs that target 88 different host glycogenes on hepatitis B surface antigen (HBsAg) and HBV DNA secretion using the siRNA screening system.

RESULTS

We identified four glycogenes that reduced HBsAg and/or HBV DNA secretion; however, the observed results for two of them may be due to siRNA off-target effects. Knocking down ST8SIA3, a member of the sialyltransferase family, significantly reduced both HBsAg and HBV DNA secretion. Knocking down GALNT7, which transfers N-acetylgalactosamine to initiate O-linked glycosylation in the Golgi apparatus, also significantly reduced both HBsAg and HBV DNA levels.

CONCLUSIONS

These results showed that knocking down the ST8SIA3 and GALNT7 glycogenes inhibited HBsAg and HBV DNA secretion in HepG2.2.15.7 cells, indicating that the host glycosylation pathway is important for the HBV life cycle and could be a potential target for the development of novel anti-HBV agents.

Inhibitory Effect of a Human MicroRNA, miR-6133-5p, on the Fibrotic Activity of Hepatic Stellate Cells in Culture

BACKGROUND

We recently identified 39 human microRNAs, which effectively suppress hepatitis B virus (HBV) replication in hepatocytes. Chronic HBV infection often results in active, hepatitis-related liver fibrosis; hence, we assessed whether any of these microRNAs have anti-fibrotic potential and predicted that miR-6133-5p may target several fibrosis-related genes.

METHODS

The hepatic stellate cell line LX-2 was transfected with an miR-6133-5p mimic and subsequently treated with Transforming growth factor (TGF)-β. The mRNA and protein products of the COL1A1 gene, encoding collagen, and the ACTA2 gene, an activation marker of hepatic stellate cells, were quantified.

RESULTS

The expression of COL1A1 and ACTA2 was markedly reduced in LX-2 cells treated with miR-6133-5p. Interestingly, phosphorylation of c-Jun N-terminal kinase (JNK) was also significantly decreased by miR-6133-5p treatment. The expression of several predicted target genes of miR-6133-5p, including TGFBR2 (which encodes Transforming Growth Factor Beta Receptor 2) and FGFR1 (which encodes Fibroblast Growth Factor Receptor 1), was also reduced in miR-6133-5p-treated cells. The knockdown of TGFBR2 by the corresponding small interfering RNA greatly suppressed the expression of COL1A1 and ACTA2. Treatment with the JNK inhibitor, SP600125, also suppressed COL1A1 and ACTA2 expression, indicating that TGFBR2 and JNK mediate the anti-fibrotic effect of miR-6133-5p. The downregulation of FGFR1 may result in a decrease of phosphorylated Akt, ERK (extracellular signal-regulated kinase), and JNK.

CONCLUSION

miR-6133-5p has a strong anti-fibrotic effect, mediated by inactivation of TGFBR2, Akt, and JNK.

Pilot study of tenofovir disoproxil fumarate and pegylated interferon-alpha 2a add-on therapy in Japanese patients with chronic hepatitis B

BACKGROUND

A prospective pilot study of tenofovir disoproxil fumarate (TDF) and pegylated interferon alpha 2a (P-IFN) add-on therapy was conducted to evaluate its efficacy in reducing viral antigen levels in Japanese patients with chronic hepatitis B (UMIN 000020179).

METHODS

Patients with chronic hepatitis B receiving maintenance TDF therapy and exhibiting hepatitis B surface antigen (HBsAg) level > 800 IU/ml were divided into two arms. P-IFN was added for 48 weeks in the add-on arm (n = 32), while TDF monotherapy was maintained in the control arm (n = 51). Both groups were followed for 96 weeks after baseline measurements.

RESULTS

Almost all patients in the control arm displayed a slow and constant reduction in HBsAg during follow-up. In contrast, roughly half of the add-on arm exhibited a sharp decline in HBsAg during P-IFN administration, which disappeared after halting P-IFN. At 96 weeks after baseline, 41% (13/32) of patients in the add-on arm had shown a rapid decrease in HBsAg, versus 2% (1/51) in the control arm (p < 0.001). Add-on therapy and increased cytotoxic T-cell response were significant factors associated with a rapid decrease in HBsAg according to multivariate analysis. In addition, higher HB core-related antigen (HBcrAg) level at baseline (p = 0.001) and add-on therapy (p = 0.036) were significant factors associated with a rapid reduction in HBcrAg.

CONCLUSIONS

TDF and P-IFN add-on therapy in Japanese patients with chronic hepatitis B facilitated rapid decreases in HBsAg and HBcrAg. Further studies are needed to improve early HBsAg clearance rate.

Cross-Protection of Hepatitis B Vaccination among Different Genotypes

Hepatitis B (HB) vaccination is the most effective method for preventing HB virus (HBV) infection. Universal HB vaccination containing recombinant HB surface antigens (HBsAg) is recommended. Our data revealed that human monoclonal HB surface antibody (anti-HBs) from individuals inoculated with genotype C-based HB vaccine induced cross-protection against HBV genotype A infection. An in vitro infection model demonstrated anti-HBs-positive sera from individuals inoculated with genotype A- or C-based HB vaccine harbored polyclonal anti-HBs that could bind to non-vaccinated genotype HBV. However, because there were low titers of anti-HBs specific for HBsAg of non-vaccinated genotype, high anti-HBs titers would be required to prevent non-vaccinated genotype HBV infection. Clinically, the 2015 Centers for Disease Control and Prevention guidelines state that periodic monitoring of anti-HBs levels after routine HB vaccination is not needed and that booster doses of HB vaccine are not recommended. However, the American Red Cross suggests that HB-vaccine-induced immune memory might be limited; although HB vaccination can prevent clinical liver injury (hepatitis), subclinical HBV infections of non-vaccinated genotypes resulting in detectable HB core antibody could not be completely prevented. Therefore, monitoring anti-HBs levels after routine vaccination might be necessary for certain subjects in high-risk groups.

Ultra-high sensitivity HBsAg assay can diagnose HBV reactivation following rituximab-based therapy in patients with lymphoma

BACKGROUND & AIMS

HBV reactivation is a risk in patients receiving anti-CD20 antibodies for the treatment of lymphoma. The purpose of this post hoc analysis was to evaluate the efficacy of an ultra-high sensitivity HBsAg assay to guide preemptive antiviral treatment in patients with lymphoma and resolved HBV infections using prospectively stored samples from an HBV DNA monitoring study.

METHODS

HBV reactivation (defined as HBV DNA levels of ≥11 IU/ml) was confirmed in 22 of 252 patients. A conventional HBsAg assay (ARCHITECT, cut-off value: 0.05 IU/ml) and an ultra-high sensitivity HBsAg assay employing a semi-automated immune complex transfer chemiluminescence enzyme technique (ICT-CLEIA, cut-off value: 0.0005 IU/ml) were performed at baseline, at confirmed HBV reactivation and monitored after HBV reactivation.

RESULTS

Baseline HBsAg was detected using ICT-CLEIA in 4 patients; in all of whom precore mutants with high replication capacity were reactivated. Of the 6 patients with HBV DNA detected below the level of quantification at baseline, 5 showed HBV reactivation and 3 of the 5 had precore mutations. Sensitivity for detection by ARCHITECT and ICT-CLEIA HBsAg assays at HBV reactivation or the next sampling after HBV reactivation was 18.2% (4 of 22) and 77.3% (17 of 22), respectively. Of the 5 patients undetectable by ICT-CLEIA, HBV reactivation resolved spontaneously in 2 patients. All 6 patients reactivated with precore mutations including preS deletion could be diagnosed by ICT-CLEIA HBsAg assay at an early stage of HBV reactivation. Multivariate analysis showed that an anti-HBs titer of less than 10 mIU/ml, HBV DNA detected but below the level of quantification, and HBsAg detected by ICT-CLEIA at baseline were independent risk factors for HBV reactivation (adjusted hazard ratios, 15.4, 31.2 and 8.7, respectively; p <0.05).

CONCLUSIONS

A novel ICT-CLEIA HBsAg assay is an alternative method to diagnose HBV reactivation.

CLINICAL TRIAL NUMBER

UMIN000001299.

LAY SUMMARY

Hepatitis B virus can be reactivated in lymphoma patients receiving anti-CD20 antibodies such as rituximab. Currently, reactivation requires the monitoring of HBV DNA, but monitoring of the surface antigen (HBsAg) could provide a relatively inexpensive, quick and easy alternative. We assessed the performance of an ultra-high sensitivity HBsAg assay and showed that it could be effective for the diagnosis and monitoring of HBV reactivation.

Marked heterogeneity in the diagnosis of compensated cirrhosis of patients with chronic hepatitis C virus infection in a real-world setting: A large, multicenter study from Japan

BACKGROUND AND AIM

The presence of cirrhosis is an important factor for the management of patients with hepatitis C virus (HCV) infection and it determines the duration of treatment for HCV with the direct-acting antiviral (DAA) regimen of glecaprevir (GLE) and pibrentasvir (PIB), that is, 8 or 12 weeks, if patients do not have a history of DAA failure. However, in real-world settings, determination of cirrhosis depends on the discretion of the attending hepatologists, and it is unclear whether compensated cirrhosis was homogenously diagnosed or not. In this study, we investigated the real-world diagnosis of cirrhosis by characterizing DAA-naïve patients who underwent a 12-week GLE/PIB regimen in whom cirrhosis was diagnosed, comparing their characteristics with those of patients who underwent an 8-week regimen in whom cirrhosis was absent.

METHODS

In a large, multicenter cohort study, we compared background characteristics and treatment outcomes among DAA-naïve patients who underwent an 8-week versus a 12-week GLE/PIB regimen.

RESULTS

Among 977 patients enrolled, 296 (30.3%) were determined to have cirrhosis and underwent a 12-week regimen. Some patient characteristics largely overlapped between the two groups, including liver fibrosis indices. Sustained viral response rates were similar between groups after adjusting liver fibrosis index with propensity score matching.

CONCLUSION

Although adequately diagnosed, the determination of cirrhosis varied widely among institutions or by hepatologists in real-world settings, and the severity of liver fibrosis overlapped significantly between patients in whom compensated cirrhosis was determined to be present and patients in whom cirrhosis was absent. Virologic efficacy was similar after adjusting for the degree of liver fibrosis.

Management of patients with liver derangement during the COVID-19 pandemic: an Asia-Pacific position statement

The COVID-19 pandemic has spread rapidly worldwide. It is common to encounter patients with COVID-19 with abnormal liver function, either in the form of hepatitis, cholestasis, or both. The clinical implications of liver derangement might be variable in different clinical scenarios. With growing evidence of its clinical significance, it would be clinically helpful to provide practice recommendations for various common clinical scenarios of liver derangement during the COVID-19 pandemic. The Asia-Pacific Working Group for Liver Derangement during the COVID-19 Pandemic was formed to systematically review the literature with special focus on the clinical management of patients who have been or who are at risk of developing liver derangement during this pandemic. Clinical scenarios covering the use of pharmacological treatment for COVID-19 in the case of liver derangement, and assessment and management of patients with chronic hepatitis B or hepatitis C, non-alcoholic fatty liver disease, liver cirrhosis, and liver transplantation during the pandemic are discussed.