The Yin and the Yang of Treatment for Chronic Hepatitis B-When to Start, When to Stop Nucleos(t)ide Analogue Therapy

Circulating capsid-antibody-complexes (CACs) drive intrahepatic complement deposition and inform subclinical liver inflammation in chronic hepatitis B

Chronic infection with Hepatitis B Virus (HBV) often results in a dysfunctional virus-specific T cell response hampering viral clearance. Paradoxically, intrahepatic inflammatory responses that contribute more to liver histopathology than to viral suppression are commonly observed, which are widely believed to be cell mediated. The involvement of humoral immunity in this process however is not well documented. To investigate the possible roles of HBV Capsid-Antibody Complexes (CACs) in eliciting chronic liver inflammation, we developed a novel microplate-based assay for the quantification of CACs in serum. The CACs assay showed high sensitivity and specificity with its readout closely correlating with the molecular features of CACs. A cross-sectional study on untreated chronic hepatitis B (CHB) patients showed a 77% positive rate for CACs with significant association with alanine transaminase (ALT), intrahepatic inflammation, and complement deposition, suggestive of its functional role in hepatic injury. Multiple staining of complement activation fragment C4d with major leukocyte and myofibroblast markers revealed an intertwined picture in periportal area with a morphology reminiscent of "piecemeal necrosis". In a pooled cohort with ALT levels lower than 40 IU/ml, CACs alone revealed subclinical liver inflammation. We provide definitive evidence for a causative role for CACs in complement-mediated intrahepatic immunopathology, an additional mechanism contributing to liver damage in CHB. Assessment of CACs in serum complements current clinical markers for assessing CHB associated inflammation.

Small Molecule Assembly Agonist Alters the Dynamics of Hepatitis B Virus Core Protein Dimer and Capsid

Chronic hepatitis B virus (HBV) poses a significant public health burden worldwide, encouraging the search for curative antivirals. One approach is capsid assembly modulators (CAMs), which are assembly agonists. CAMs lead to empty and defective capsids, inhibiting the formation of new viruses, and can also lead to defects in the release of the viral genome, inhibiting new infections. In this study, we employed hydrogen-deuterium exchange mass spectrometry (HDX-MS) to assess the impact of one such CAM, HAP18, on HBV dimers, capsids composed of 120 (or 90) capsid protein dimers, and cross-linked capsids (xl-capsids). HDX analysis revealed hydrogen bonding networks within and between the dimers. HAP18 disrupted the hydrogen bonding network of dimers, demonstrating a previously unappreciated impact on the dimer structure. Conversely, HAP18 stabilized both unmodified and cross-linked capsids. Intriguingly, cross-linking the capsid, which was accomplished by forming disulfides between an engineered C-terminal cysteine, increased the overall rate of HDX. Moreover, HAP18 binding induced conformational changes beyond the binding sites. Our findings provide evidence for allosteric communication within and between capsid protein dimers. These results show that CAMs are capable of harnessing this allosteric network to modulate the dimer and capsid dynamics.

Discontinuation of Nucleos(t)ide Analogues in HBeAg Negative Chronic Hepatitis B Patients: Risks and Benefits

Chronic hepatitis B (CHB) remains a major threat to global public health, affecting 296 million people worldwide. Although there is no curative treatment for CHB today, the virus can be effectively controlled with current antiviral treatment strategies. Since HBsAg loss can rarely (1%) be achieved with current nucleos(t)ide analogues (NA) options, lifelong treatment is usually required in HBeAg-negative patients. In recent years, guidelines have stated that long-term NA treatments can be discontinued for HBeAg-negative patients without achieving HBsAg loss. There is no general consensus on how discontinuation of NA can be included in the treatment approach. This review aimed to evaluate the current literature regarding the discontinuation of NA treatment in HBeAg-negative patients. Patients with HBeAg-negative CHB who have a higher chance of response after discontinuation of NA therapy can be defined as non-cirrhotic patients who have low HBsAg, HBcrAg, and HBV RNA levels at the discontinuation of treatment and accept close follow-up. The management of relapses that develop after NA discontinuation in patients is also unclear. The agent used in NA treatment itself may also affect the pattern of relapse development. Relapse after NA treatment occurs significantly slower and less frequently with entecavir compared to other regimens, including tenofovir dipivoxil. Prospective studies are needed in order to maintain the chance of HBsAg clearance in case of exacerbation and to treat acute exacerbations that can be fatal in a timely manner. Algorithms to be developed for use after discontinuation of NA treatment will help the clinician manage the patient safely.

Discontinuation of Nucleos(t)ide Analog treatment in HBeAg-Negative Non-Cirrhotic Chronic Hepatitis B Patients: Real-Life Data of 20 Years

BACKGROUND/AIMS

Discontinuation of nucleos(t)ide analog is controversial in HBeAg-negative chronic hepatitis B patients not achieved HBsAg loss. We aimed to evaluate re-treatment rates and risk factors in non-cirrhotic HbeAg-negative chronic hepatitis B patients for whom nucleosi(t)ides analogs were discontinued.

MATERIALS AND METHODS

Demographic, clinical, and laboratory data before and at the end after discontinuation of nucleos(t)ide analogs were collected retrospectively.

RESULTS

Seventy-two patients followed up between January 2000 and December 2019 were included; 43 were male, with a mean age of 46.3 (±10.8). Baseline median alanine aminotransferase (ALT) and hepatitis B virus DNA levels were 55.5 IU/L and 465 925 IU/mL, respectively. The median histologic activity index was 5.5 and the fibrosis score was 2. The median duration of treatment and consolidation therapy were 59 and 56 months, respectively. The median follow-up time after discontinuation of treatment was 55 months. Among 56 patients eligible for evaluation according to proposed re-treatment criteria, 29 (51.7%) patients were re-treated. The median time for relapse was 11 months. Re-treatment was significantly common in males (P = .034) and patients treated with tenofovir/entecavir (P = .04). Baseline hepatitis B virus DNA and levels of ALT, aspartate aminotransferase (AST) at the third and sixth months of treatment and at the end of treatment were statistically significantly higher in re-treated patients. A cutoff value of ≥405 000 IU/L for hepatitis B virus DNA discriminated patients for re-treatment. HBsAg was lost permanently in 2 non-re-treated patients.

CONCLUSION

In resource-limited areas where follow-up of HBsAg or other markers is not possible, nucleos(t)ide analog discontinuation can be considered in patients in the early stage, with low baseline hepatitis B virus DNA and ALT levels, after a long consolidation therapy.

Letter: Consensus in international guidelines when discontinuing nucleos(t)ide analogue therapy in patients with chronic hepatitis B

This article is linked to Hsu et al paper. To view this article, visit https://doi.org/10.1111/apt.17614

A hepatitis B virus-derived peptide combined with HBsAg exerts an anti-HBV effect in an HBV transgenic mouse model as a therapeutic vaccine

Introduction

For complete or functional cure of hepatitis B virus (HBV) infection, application of immunotherapy is now being attempted. Recently, we reported that a 6-mer hepatitis B virus (HBV)-derived peptide, Poly6, exerts a strong anticancer effect in tumor-implanted mice through inducible nitric oxide synthase (iNOS)-producing DCs (Tip-DCs) in a type 1 interferon (IFN-I)-dependent manner, suggesting its potential as a vaccine adjuvant.

Methods

In this study, we explored the potential of Poly6 in combination with HBsAg as a therapeutic vaccine against hepatitis B virus infection. We investigated the immunotherapeutic potential of Poly6 combined with HBsAg vaccination against hepatitis B virus infection in C57BL/6 mice or an HBV transgenic mouse model.

Results

In C57BL/6 mice, Poly6 enhanced DC maturation and DC migration capacity in an IFN-I-dependent manner. Moreover, the addition of Poly6 to alum in combination with HBsAg also led to enhanced HBsAg-specific cell-mediated immune (CMI) responses, suggesting its potential as an adjuvant of HBsAg-based vaccines. In HBV transgenic mice, vaccination with Poly6 combined with HBsAg exerted a strong anti-HBV effect via induction of HBV-specific humoral and cell-mediated immune responses. In addition, it also induced HBV-specific effector memory T cells (T_EM).

Discussion

Our data indicated that vaccination with Poly6 in combination with HBsAg exerts an anti-HBV effect in HBV transgenic mice, which is mainly mediated by HBV-specific CMI and humoral immune responses via IFN-I-dependent DC activation, suggesting the feasibility of Poly6 as an adjuvant for an HBV therapeutic vaccine.

The Impact of Nucleos(t)ide Analogs Off-Therapy Among Chronic Hepatitis B Patients: A Systematic Review and Meta-Analysis

Background and Aim: Although most chronic hepatitis B (CHB) patients achieve effective virological suppression after receiving long-term nucleos(t)ide analogs (Nucs) therapy, the safety of off-therapy is controversial under the monitor.

Methods: We identified studies through searching PubMed, Embase, Cochrane Library, and Web of Science from January 1990 to February 2021. The eligible studies compare the long outcomes between discontinued and continued Nucs treatments groups among CHB patients. This study was conducted to investigate long-term outcomes, including biochemical, serological, and virological outcomes, as well as hepatocellular carcinoma (HCC) development rate between discontinued and maintained Nucs therapy groups among CHB patients.

Results: Five eligible studies covering 1,425 patients were selected for meta-analysis. Our result exhibits that patients with Nucs off-treatment have a higher risk of alanine aminotransferase (ALT) flares-up than those who continued Nucs therapy under the monitor (OR = 9.39, 95%CI = 3.87–22.78). Nucs off-therapy patients have a higher virological bound incidence (OR = 617.96, 95%CI = 112.48–3,395.14) and a higher HBV DNA level (OR = 9.39, 95%CI = 3.87–22.78) than those who continued Nucs therapy. There was no statistically significant difference in the risk of hyperbilirubinaemia, hepatic decompensation, and HCC development between both two groups. Patients in Nucs off-therapy group demonstrate a higher HBsAg loss rate than those in the continued group (OR = 7.10, 95%CI = 6.68–13.69).

Conclusions: Nucs off-therapy patients may exhibit a higher chance of achieving HBsAg loss than those who continue Nucs therapy. It requires close monitoring after Nucs off-therapy and timely restarting of Nucs therapy when ALT concentrations increase.

HBV and HDV: New Treatments on the Horizon

Despite the accumulating knowledge, chronic hepatitis B (CHB) and HDV infection represent a global health problem, and there are still several critical issues, which frequently remain uncovered. In this paper, we provided an overview of the current therapeutic options and summarized the investigational therapies in the pipeline. Furthermore, we discussed some critical issues such as a “functional cure” approach, the futility of long-term NA therapy and the relevance of understanding drug actions and safety of antivirals, especially in special populations.

Nucleoside/nucleotide analog consolidation therapy in hepatitis B e-antigen positive chronic hepatitis B patients: Three years should be preferred

AIM

To assess the role of consolidation therapy after cessation of nucleoside/nucleotide analogs (NAs) for off-treatment outcome and to explore the optimal consolidation period in hepatitis B e-antigen (HBeAg) positive chronic hepatitis B (CHB) patients.

METHODS

We undertook a prospective, observational cohort study including HBeAg positive CHB patients discontinuing NAs. Virological relapse was the primary endpoint of the current study and was defined as a serum hepatitis B virus DNA more than 10⁴ copies/ml (another assay was carried out for confirmation at least 2 weeks later). Propensity score matching analysis was used to balance the baseline characteristics between HBeAg positive CHB patients with different consolidation periods.

RESULTS

A total of 190 HBeAg positive CHB patients were included. Fifty-four patients relapsed during follow-up and the cumulative relapse rates at years 1, 3, 5, and 10 were 19.5%, 24.1%, 27.2%, and 32.1%, respectively. Most patients (61.1%) relapsed in the first 6 months. After propensity score matching, significantly lower cumulative relapse rates were observed in patients with consolidation period ≥36 months compared with patients with consolidation period more than 36 months (29.3% vs. 52.8% at year 10; p = 0.012).

CONCLUSIONS

Cessation of NAs after HBeAg seroconversion and long-term consolidation is generally safe and feasible in HBeAg positive CHB patients. Three years of consolidation should be preferred in clinical practice.

Tenofovir, Another Inexpensive, Well-Known and Widely Available Old Drug Repurposed for SARS-COV-2 Infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is spreading worldwide with different clinical manifestations. Age and comorbidities may explain severity in critical cases and people living with human immunodeficiency virus (HIV) might be at particularly high risk for severe progression. Nonetheless, current data, although sometimes contradictory, do not confirm higher morbidity, risk of more severe COVID-19 or higher mortality in HIV-infected people with complete access to antiretroviral therapy (ART). A possible protective role of ART has been hypothesized to explain these observations. Anti-viral drugs used to treat HIV infection have been repurposed for COVID-19 treatment; this is also based on previous studies on severe acute respiratory syndrome virus (SARS-CoV) and Middle East respiratory syndrome virus (MERS-CoV). Among them, lopinavir/ritonavir, an inhibitor of viral protease, was extensively used early in the pandemic but it was soon abandoned due to lack of effectiveness in clinical trials. However, remdesivir, a nucleotide analog that acts as reverse-transcriptase inhibitor, which was tested early during the pandemic because of its wide range of antiviral activity against several RNA viruses and its safety profile, is currently the only antiviral medication approved for COVID-19. Tenofovir, another nucleotide analog used extensively for HIV treatment and pre-exposure prophylaxis (PrEP), has also been hypothesized as effective in COVID-19. No data on tenofovir's efficacy in coronavirus infections other than COVID-19 are currently available, although information relating to SARS-CoV-2 infection is starting to come out. Here, we review the currently available evidence on tenofovir's efficacy against SARS-CoV-2.

In Vitro Infection with Hepatitis B Virus Using Differentiated Human Serum Culture of Huh7.5-NTCP Cells without Requiring Dimethyl Sulfoxide

An estimated two billion people worldwide have been infected with hepatitis B virus (HBV). Despite the high infectivity of HBV in vivo, a lack of easily infectable in vitro culture systems hinders studies of HBV. Overexpression of the sodium taurocholate co-transporting polypeptide (NTCP) bile acid transporter in hepatoma cells improved infection efficiency. We report here a hepatoma cell culture system that does not require dimethyl sulfoxide (DMSO) for HBV infection. We overexpressed NTCP in Huh7.5 cells and allowed these cells to differentiate in a medium supplemented with human serum (HS) instead of fetal bovine serum (FBS). We show that human serum culture enhanced HBV infection in Huh7.5-NTCP cells, e.g., in HS cultures, HBV pgRNA levels were increased by as much as 200-fold in comparison with FBS cultures and 19-fold in comparison with FBS+DMSO cultures. Human serum culture increased levels of hepatocyte differentiation markers, such as albumin secretion, in Huh7.5-NTCP cells to similar levels found in primary human hepatocytes. N-glycosylation of NTCP induced by culture in human serum may contribute to viral entry. Our study demonstrates an in vitro HBV infection of Huh7.5-NTCP cells without the use of potentially toxic DMSO.