HBeAg-positive patients with HBsAg < 100 IU/mL and negative HBV RNA have lower risk of virological relapse after nucleos(t)ide analogues cessation

Predictors of hepatic flares after nucleos(t)ide analogue cessation - Results of a global cohort study (RETRACT-B study)

BACKGROUND & AIMS

Flares after nucleos(t)ide analogue (NA) cessation are common and potentially harmful. Predictors of flares are required for risk stratification and to guide off-treatment follow-up.

METHOD

This multicenter cohort study included virally suppressed patients with chronic hepatitis B (CHB) who were hepatitis B e antigen negative at NA cessation. Hepatic flares were defined based on ALT levels of ≥5x, 10x or 20x the upper limit of normal (ULN). Multivariable Cox regression analyses were performed with censoring at retreatment, HBsAg loss or loss to follow-up. A sub-analysis was performed including HBV DNA levels within the first 12 weeks as a time-dependent covariate.

RESULTS

Of the 1,552 included patients, 350 developed a flare (ALT ≥5x ULN), of whom 70.6% did within the first year. One-year cumulative incidences for ALT flares ≥5x, ≥10x, ≥20x ULN were 18.6%, 10.2% and 3.4%, respectively. Severity of flares decreased over time, but severe flares still occurred after 1 year. Thirteen patients decompensated after a flare, of whom three died. Flares did not seem to be associated with increased rates of HBsAg loss (adjusted hazard ratio [aHR] 1.42, p = 0.28). Multivariable analyses showed that older age (aHR 1.02, p = 0.001), male sex (aHR 1.57, p = 0.003), HBsAg levels at NA withdrawal (100-1,000 IU/ml; aHR 1.99, p <0.001; >1,000 IU/ml; aHR 2.65, p <0.001) and tenofovir disoproxil fumarate vs. entecavir therapy (aHR 2.99, p <0.001) were predictive of flares (≥5x ULN). Early HBV DNA levels >5log10 IU/ml were associated with the highest risk of flares (aHR 2.36, p <0.001).

CONCLUSION

Flares are common after NA withdrawal, especially within the first year and can result in hepatic decompensation and death. Older age, male sex, higher HBsAg levels at end of treatment and tenofovir therapy were associated with a higher risk of flares. Close monitoring and retreatment should be considered if HBV DNA levels exceed 5log10 IU/ml within the first 12 weeks.

IMPACT AND IMPLICATIONS

This is the first large global multi-centered cohort study which provides detailed data about flares after nucleos(t)ide analogue cessation in patients with chronic hepatitis B. Older age, male sex, higher HBsAg levels at end of treatment and tenofovir therapy were associated with a higher risk of flares. These results could guide follow-up after withdrawal, helping clinicians identify high-risk patients and decide when to restart anti-viral therapy, which we recommend if HBV DNA levels exceed 5log10 IU/ml within the first 12 weeks.

CLINICAL TRIAL NUMBER

not applicable.

Achieving chronic hepatitis B functional cure: Factors and potential mechanisms

Chronic hepatitis B (CHB) is a significant global health issue affecting approximately 254 million individuals worldwide. Achieving the loss of hepatitis B surface antigen (HBsAg), either with or without seroconversion to hepatitis B surface antibody (HBsAb), is regarded as a functional cure and the optimal goal for addressing CHB, and can be achieved through various approaches, including induction with nucleos(t)ide analogues (NAs), induction with pegylated interferon alpha (PegIFNα), and spontaneous clearance of HBsAg. Spontaneous clearance of HBsAg is rare, while NAs can directly inhibit HBV DNA, they are unable to act on covalently closed circular DNA (cccDNA), hence inhibiting HBsAg production or clearing HBsAg is extremely challenging. On the other hand, functional cure based on PegIFNα shows good long-term durability, but over 10 % of patients still experience relapse, mostly within 48 weeks after functional cure. Factors related to CHB functional cure with antiviral therapy are complex, including host factors, viral factors, environmental factors, etc. The integration of HBV DNA into liver cells, persistence of HBV cccDNA, insufficient B cell responses and compromised T cell function pose significant barriers to HBV clearance. Therefore, this study systematically reviewed the relevant factors and potential mechanisms influencing functional cure CHB, which can provide a basis for personalized treatment, help predict treatment outcomes and assess prognosis, and provide theoretical support for the advancement of novel treatment strategies and medications.

CRISPR-Cas13b-mediated suppression of HBV replication and protein expression

BACKGROUND & AIMS

New antiviral approaches that target multiple aspects of the HBV replication cycle to improve rates of functional cure are urgently required. HBV RNA represents a novel therapeutic target. Here, we programmed CRISPR-Cas13b endonuclease to specifically target the HBV pregenomic RNA and viral mRNAs in a novel approach to reduce HBV replication and protein expression.

METHODS

Cas13b CRISPR RNAs (crRNAs) were designed to target multiple regions of HBV pregenomic RNA. Mammalian cells transfected with replication competent wild-type HBV DNA of different genotypes, a HBV-expressing stable cell line, a HBV infection model and a hepatitis B surface antigen (HBsAg)-expressing stable cell line were transfected with PspCas13b-BFP (blue fluorescent protein) and crRNA plasmids, and the impact on HBV replication and protein expression was measured. Wild-type HBV DNA, PspCas13b-BFP and crRNA plasmids were simultaneously hydrodynamically injected into mice, and serum HBsAg was measured. PspCas13b mRNA and crRNA were also delivered to a HBsAg-expressing stable cell line via lipid nanoparticles and the impact on secreted HBsAg determined.

RESULTS

Our HBV-targeting crRNAs strongly suppressed HBV replication and protein expression in mammalian cells by up to 96% (p <0.0001). HBV protein expression was also reduced in a HBV-expressing stable cell line and in the HBV infection model. CRISPR-Cas13b crRNAs reduced HBsAg expression by 50% (p <0.0001) in vivo. Lipid nanoparticle-encapsulated PspCas13b mRNA reduced secreted HBsAg by 87% (p = 0.0168) in a HBsAg-expressing stable cell line.

CONCLUSIONS

Together, these results show that CRISPR-Cas13b can be programmed to specifically target and degrade HBV RNAs to reduce HBV replication and protein expression, demonstrating its potential as a novel therapeutic option for chronic HBV infection.

IMPACT AND IMPLICATIONS

Owing to the limitations of current antiviral therapies for hepatitis B, there is an urgent need for new treatments that target multiple aspects of the HBV replication cycle to improve rates of functional cure. Here, we present CRISPR-Cas13b as a novel strategy to target HBV replication and protein expression, paving the way for its development as a potential new treatment option for patients living with chronic hepatitis B.

Assessment of hepatitis B virus relapse in cancer patients receiving chemotherapy with prophylactic nucleos(t)ide analogues: Implications for overall mortality

BACKGROUND AND AIMS

We aimed to explore the risk factors associated with virological and clinical relapse, as well as their impact on overall mortality, in hepatitis B virus (HBV)-infected patients receiving nucleos(t)ide analogues (NUCs) therapy prior to chemotherapy initiation.

METHODS

From 2010 to 2020, we conducted a prospective cohort study involving patients with HBV infection undergoing cytotoxic chemotherapy. We utilized the Kaplan-Meier method and Cox proportional hazard regression models to assess risk factors.

RESULTS

We observed that TDF or TAF (HR: 2.16, 95% CI 1.06-4.41; p = .034), anthracycline (HR: 1.73, 95% CI 1.10-2.73; p = .018), baseline HBV DNA (HR: 1.55, 95% CI 1.33-1.81; p < .001) and end-of-treatment HBsAg titre >100 IU/mL (HR: 7.81, 95% CI 1.94-31.51; p = .004) were associated with increased risk of virological relapse. Additionally, TDF or TAF (HR: 4.91, 95% CI 1.45-16.64; p = .011), baseline HBV DNA (HR: 1.48, 95% CI 1.10-1.99; p = .009) and end-of-treatment HBsAg titre >100 IU/mL (HR: 6.09, 95% CI .95-38.87; p = .056) were associated with increased risk of clinical relapse. Furthermore, we found that virological relapse (HR: 3.32, 95% CI 1.33-8.32; p = .010) and clinical relapse (HR: 3.59, 95% CI 1.47-8.80; p = .005) significantly correlated with all-cause mortality in HBV patients receiving cytotoxic chemotherapy with prophylactic NUCs therapy.

CONCLUSIONS

The risk of virological and clinical relapse was linked to baseline HBV DNA, end-of-treatment HBsAg levels and TDF or TAF for prophylaxis; additionally, experiencing relapse heightens the risk of all-cause mortality. Further research is warranted to explore potential strategies for preventing virological and clinical relapse in high-risk patients.

The impact of integrated hepatitis B virus DNA on oncogenesis and antiviral therapy

The global burden of hepatitis B virus (HBV) infection remains high, with chronic hepatitis B (CHB) patients facing a significantly increased risk of developing cirrhosis and hepatocellular carcinoma (HCC). The ultimate objective of antiviral therapy is to achieve a sterilizing cure for HBV. This necessitates the elimination of intrahepatic covalently closed circular DNA (cccDNA) and the complete eradication of integrated HBV DNA. This review aims to summarize the oncogenetic role of HBV integration and the significance of clearing HBV integration in sterilizing cure. It specifically focuses on the molecular mechanisms through which HBV integration leads to HCC, including modulation of the expression of proto-oncogenes and tumor suppressor genes, induction of chromosomal instability, and expression of truncated mutant HBV proteins. The review also highlights the impact of antiviral therapy in reducing HBV integration and preventing HBV-related HCC. Additionally, the review offers insights into future objectives for the treatment of CHB. Current strategies for HBV DNA integration inhibition and elimination include mainly antiviral therapies, RNA interference and gene editing technologies. Overall, HBV integration deserves further investigation and can potentially serve as a biomarker for CHB and HBV-related HCC.

Chronic Hepatitis B Finite Treatment: Similar and Different Concerns With New Drug Classes

Chronic hepatitis B, a major cause of liver disease and cancer, affects >250 million people worldwide. Currently there is no cure, only suppressive therapies. Efforts to develop finite curative hepatitis B virus (HBV) therapies are underway, consisting of combinations of multiple novel agents with or without nucleos(t)ide reverse-transcriptase inhibitors. The HBV Forum convened a webinar in July 2021, along with subsequent working group discussions to address how and when to stop finite therapy for demonstration of sustained off-treatment efficacy and safety responses. Participants included leading experts in academia, clinical practice, pharmaceutical companies, patient representatives, and regulatory agencies. This Viewpoints article outlines areas of consensus within our multistakeholder group for stopping finite therapies in chronic hepatitis B investigational studies, including trial design, patient selection, outcomes, biomarkers, predefined stopping criteria, predefined retreatment criteria, duration of investigational therapies, and follow-up after stopping therapy. Future research of unmet needs are discussed.

Evaluation of chronic hepatitis B patients who voluntarily discontinued oral antiviral therapy: is there an answer to the controversial topic?

OBJECTIVE

The uncertain treatment duration for nucleos(t)ide analogues (NA) used in the treatment of chronic hepatitis B (CHB) is an important problem for both patients and physicians. The aim of this study was to evaluate the determinants of virologic relapse (VR) and the optimum time of treatment discontinuation in the follow-up of CHB patients who voluntarily discontinued treatment after virological suppression was achieved under NA use.

METHODS

Data from 138 patients from 11 centers were included in this registry-based study. Factors associated with VR were investigated using multivariate Cox regression analysis.

RESULTS

Ninety-nine (71.7%) of the patients were HBeAg (Hepatitis B e antigen) negative. During the 24-month follow-up period after treatment discontinuation, VR occurred in 58.7% (n = 81) of all patients and 57.6% (n = 57) of HBeAg-negative patients. The duration of NA treatment was significantly shorter (cutoff 60 months) in HBeAg-negative patients who later developed VR. In addition, the duration of virologic remission achieved under NA treatment was significantly shorter (cutoff 52 months) in those who later developed VR. In the Cox multivariate regression model of HBeAg-negative patients, having less than 60 months of NA treatment (HR = 2.568; CI:1.280-5.148; P  = 0.008) and the levels of alanine aminotransferase being equal to or higher than twice the upper level of normal at the beginning of treatment (HR = 3.753; CI:1.551-9.081; P  = 0.003) were found to be statistically significant and independently associated with VR.

CONCLUSION

The findings of this study may provide clinical guidance in terms of determining the most appropriate discontinuation time for NA.

Higher HBeAg-reversion virological relapse and lower sustained remission after treatment cessation in tenofovir-treated HBeAg-positive patients

A complete investigation of the clinical outcomes after treatment cessation in HBeAg-positive patients with HBeAg loss is limited. We retrospectively recruited 242 HBeAg-positive patients with HBeAg loss after a median duration of 37.2 months with tenofovir (TDF, n = 77) or entecavir (ETV, n = 165) treatment. There were 77 (31.8%) patients with sustained virological remission (SVR), 85 (35.1%) with HBeAg-reversion virological relapse, 80 (33.1%) with HBeAg-negative virological relapse after treatment cessation, and 23 (9.5%) with HBsAg loss. Clinical data at baseline, on-treatment and during off-treatment follow-up were analyzed. The 3-year cumulative incidences of overall, HBeAg-reversion and HBeAg-negative virological relapse were 70.2%, 54%, and 53.5%, respectively. The common factors associated with HBeAg-reversion and HBeAg-negative virological relapse were tenofovir treatment (hazard ratio [HR] = 5.411, p < 0.001; HR = 2.066, p = 0.006, respectively) and HBsAg at end of treatment (EOT) (HR = 1.461, p = 0.001; HR = 1.303, p = 0.019, respectively). The 5-year cumulative incidence of HBsAg loss in SVR patients was 13.7% and EOT HBsAg was the only associated factor (HR = 0.524, p = 0.024). Compared to that of ETV-treated patients, TDF-treated patients had a significantly higher 3-year cumulative incidence of virological relapse (87.3% vs. 62.8%, p < 0.001), earlier HBeAg-reversion virological relapse (2.9 vs. 7.8 months, p < 0.001), a higher rate of HBeAg-reversion virological relapse (53.2% vs. 26.7%) and a lower SVR rate (15.6% vs. 39.4%) (p < 0.001). In summary, the clinical outcomes after treatment cessation in HBeAg-positive patients with HBeAg loss were composed of HBeAg-reversion virological relapse, HBeAg-negative virological relapse and SVR. TDF was significantly associated with off-treatment virological relapse. EOT HBsAg plays an important role in HBsAg loss among SVR patients and posttreatment virological relapse.

Safety considerations for withdrawal of nucleos(t)ide analogues in patients with chronic hepatitis B: First, do no harm

Nucleos(t)ide analogues (NA) are widely used to treat hepatitis B virus (HBV) infection, but they cannot eradicate the virus and treatment duration can be lifelong if the endpoint is set at seroclearance of the hepatitis B surface antigen (HBsAg). As an alternative strategy, finite NA therapy without the prerequisite of HBsAg seroclearance has been proposed to allow treatment cessation in patients with sustained undetectable HBV viremia for two to three years. However, reactivation of viral replication almost always follows NA withdrawal. Whereas HBV reactivation might facilitate HBsAg seroclearance in some, it could lead to serious acute flare-ups in a certain proportion of patients. Occurrence and consequences of NA withdrawal flares are complicated with various factors involving the virus, host, and treatment. Accurate risk prediction for severe flares following NA cessation is essential to ensure patient safety. The risks of life-threatening flares in patients who discontinued NA according to the stopping rules of current guidelines or local reimbursement policies have recently been quantitatively estimated in large-scale studies, which also provided empirical evidence to help identify vulnerable patients at risk of devastating outcomes. Moreover, risk predictors were further explored and validated to hopefully aid in patient selection and management. In this narrative review with a focus on patient safety, we summarize and discuss current literature on the incidence of severe flares following NA cessation, risk stratification for candidate selection, rules of posttreatment monitoring, and indications for treatment resumption. We also share our thoughts on the limitations of existing knowledge and suggestions for future research.

IP10 and Anti-HBc can Predict Virological Relapse and HBsAg Loss in Chronic Hepatitis B Patients after Nucleos(t)ide Analog Discontinuation

INTRODUCTION

To assess predictive ability of serum interferon-inducible protein 10 (IP10) and hepatitis B core antibody (anti-HBc) levels for virological relapse (VR) and hepatitis B surface antigen (HBsAg) loss after nucleos(t)ide analog (NA) discontinuation.

METHODS

In this multicenter prospective study, overall 139 patients were followed up for 24 months after NA discontinuation.

RESULTS

End of treatment (EOT) IP10 and anti-HBc were 29.2 (5.1-66.4) pg/mL and 193.6 (136.9-221.4) IU/mL. EOT IP10 and anti-HBc were independent predictors for VR and HBsAg loss in Cox regression analysis. Cumulative rates of VR in patients with EOT IP10 > 26.99 pg/mL was 31.9% (vs. 70.1%, hazard ratio [HR] 2.998, p < 0.001). Cumulative incidences of VR in patients with EOT anti-HBc ≤141.35 IU/mL was 49.1% (vs. 60.6%, HR 2.99, p < 0.001). Cumulative probabilities of VR was 16.7% in patients with EOT IP10 > 26.99 pg/mL plus anti-HBc ≤141.35 IU/mL (vs. 73.6%, HR 6.464, p < 0.001). Cumulative probabilities of HBsAg loss in patients with EOT IP10 > 93.5 pg/mL was 46.2% (vs. 4.7%, HR 10.94, p < 0.001). Cumulative probabilities of HBsAg loss in patients with EOT anti-HBc ≤78.42 IU/mL were 47.1% (vs. 5%, HR 12.27, p < 0.001). Patients with EOT IP10 > 93.5 pg/mL plus anti-HBc ≤78.42 IU/mL had the highest 24-month cumulative HBsAg loss rate (53.8% vs. 4%, HR 16.83, p < 0.001).

CONCLUSION

High EOT IP10 and low EOT anti-HBc levels were related to both lower risk of VR and higher probability of HBsAg loss.

Lower end of treatment HBsAg and HBcrAg were associated with HBsAg loss after nucleos(t)ide analog cessation

BACKGROUND

Since hepatitis B surface antigen (HBsAg) loss is rarely achieved with nucleos(t)ide analog (NA) treatment, most patients require life-long NA treatment. Previous studies have shown that some patients remain virologically responsive even after NA cessation. However, there is still controversy surrounding whether NA discontinuation increases the HBsAg loss rate. Therefore, this study aimed to assess the cumulative rate of HBsAg loss and identify the predictors of HBsAg loss after NA discontinuation.

METHODS

This multicenter prospective study included HBV e antigen (HBeAg)-positive patients without cirrhosis from 12 hospitals in China who met the inclusion criteria. The enrolled patients stopped NA and were followed up with clinical and laboratory assessments every 3 months for 24 months after NA cessation or until clinical relapse (CR) occurred.

RESULTS

Overall, 158 patients were classified into two groups. Group A included patients with HBsAg positivity at NA cessation (n = 139), and Group B included patients with HBsAg negativity at NA cessation (n = 19). In Group A, the 12-month and 24-month cumulative rates of HBsAg loss were4.3%and 9.4%, respectively. End of treatment (EOT) HBsAg (hazard ratio (HR) = 0.152, P < 0.001) and EOT hepatitis B core-related antigen (HBcrAg) (HR = 0.257, P = 0.001) were associated with HBsAg loss. The areas under the receiver operating characteristic curves for EOT HBsAg and HBcrAg levels were 0.952 (P < 0.001) and 0.765 (P < 0.001), respectively. Patients with EOT HBsAg ≤ 135 IU/mL (59.2% vs. 1.3%, P < 0.001) or HBcrAg ≤ 3.6 logU/mL (17% vs. 5.4%, P = 0.027) had a higher 24-month cumulative HBsAg loss rate. In Group B, none of the patients experienced virological relapse after NA cessation. Only 1 (5.3%) patient had HBsAg reversion.

CONCLUSIONS

EOT HBsAg ≤ 135 IU/mL or HBcrAg ≤ 3.6 logU/mL can be used to identify patients with a higher likelihood of HBsAg loss after NA cessation. Patients with HBsAg negativity after NA cessation have favorable clinical outcomes, and HBsAg loss was durable in most cases.

Utility of novel viral and immune markers in predicting HBV treatment endpoints: A systematic review of treatment discontinuation studies

Background & Aims

Antivirals represent the mainstay of chronic hepatitis B treatment given their efficacy and tolerability, but rates of functional cure remain low during long-term therapy. Treatment discontinuation has emerged as a strategy to maintain partial cure and achieve functional cure in select patient groups. We aimed to evaluate how data from treatment discontinuation studies exploring novel viral and/or immune markers could be applied to the functional cure program.

Methods

Treatment discontinuation studies evaluating novel viral and/or immune markers were identified by a systematic search of the PubMed database through to October 30, 2022. Data extraction focused on information regarding novel markers, including identified cut-off levels, timing of measurement, and associated effect on study outcomes of virological relapse, clinical relapse, and HBsAg seroclearance.

Results

From a search of 4,492 citations, 33 studies comprising a minimum of 2,986 unique patients met the inclusion criteria. Novel viral markers, HBcrAg and HBV RNA, were demonstrated across most studies to be helpful in predicting off-therapy partial cure, with emerging evidence to support a link with functional cure. From novel immune marker studies, we observed that treatment discontinuation has the potential to trigger immune restoration, which may be associated with a transient virological relapse. To this end, these studies support the combination of virus-directing agents with immunomodulator therapies to induce two key steps underlying functional cure: viral antigen load reduction and restoration of the host immune response.

Conclusions

Patients with a favourable profile of novel viral and immune markers stand to benefit from a trial of antiviral treatment discontinuation alongside novel virus-directing agents with the aim of achieving functional cure without excessive risk of severe clinical relapse.

Impact and implications

Select patients with chronic hepatitis B undergoing nucleoside analogue therapy may benefit from a trial of treatment discontinuation, aiming to maintain partial cure and/or achieve functional cure. We propose a profile of novel viral and immune markers to identify patients who are likely to achieve these goals without excessive risk of hepatic decompensation. Furthermore, treatment discontinuation may also be considered as a therapeutic strategy to trigger immune restoration, which may increase the chance of functional cure when used in conjunction with novel virus-directing agents.

A critique and systematic review of the clinical utility of hepatitis B core-related antigen

BACKGROUND & AIMS

Hepatitis B core-related antigen (HBcrAg) is a new biomarker for chronic hepatitis B (CHB) whose performance has not been critically or systematically appraised. Herein, we performed a systematic review to determine its clinical utility.

METHODS

We evaluated the biological pathway of HBcrAg and performed a systematic review of PubMed for clinical trials, cohort studies, and case-control studies that evaluated the clinical utility of HBcrAg. The effectiveness of HBcrAg in predicting HBV-specific clinical events (e.g. HBeAg seroconversion, phases of CHB, HBsAg loss, treatment response, and relapse after stopping therapy) was examined using receiver-operating characteristic curves. The correlation coefficients of HBcrAg with HBV DNA, quantitative HBsAg (qHBsAg), HBV RNA, and cccDNA were summarised from published studies. Median values were used as estimates.

RESULTS

HBcrAg consists of three precore/core protein products: HBcAg, HBeAg, and a 22 kDa precore protein. HBcrAg assays have been associated with false-positive rates of 9.3% and false-negative rates of between 12-35% for CHB. The new iTACT-HBcrAg is more sensitive but does not reduce the false-positive rate. A PubMed search found 248 papers on HBcrAg, of which 59 were suitable for analysis. The clinical performance of HBcrAg was evaluated using AUROC analyses, with median AUROCs of 0.860 for HBeAg seroconversion, 0.867 for predicting HBeAg(-) hepatitis, 0.645 for HBsAg loss, 0.757 for treatment response, and 0.688 for relapse after stopping therapy. The median correlation coefficient (r) was 0.630 with HBV DNA, 0.414 with qHBsAg, 0.619 with HBV RNA and 0.550 with cccDNA. Correlation decreased during antiviral therapy, but combined biomarkers improved performance.

CONCLUSIONS

HBcrAg has a mixed performance and has a poor correlation with HBsAg loss and antiviral therapy, hence HBcrAg results should be interpreted with caution.

IMPACT AND IMPLICATIONS

Hepatitis B core-related antigen (HBcrAg) has been used to assess management of patients with chronic hepatitis B (CHB) without a systematic and critical Sreview of its performance. Our finding that HBcrAg had a false-positive rate of 9% and a false-negative rate of 12-35% raises concerns, although larger studies are needed for validation. A systematic review showed that the performance of HBcrAg was variable depending on the CHB endpoint; it was excellent at predicting HBeAg seroconversion and HBeAg-negative chronic hepatitis (vs. chronic infection), which should be its main use, but it was poor for relapse after stopping antiviral therapy and for HBsAg loss. HBcrAg results should be interpreted with considerable caution, particularly by physicians, researchers, guideline committees and agencies that approve diagnostic tests.

Hepatitis B functional cure and immune response

Hepatitis B virus (HBV) is a hepatotropic virus, which damage to hepatocytes is not direct, but through the immune system. HBV specific CD4+ T cells can induce HBV specific B cells and CD8+ T cells. HBV specific B cells produce antibodies to control HBV infection, while HBV specific CD8+ T cells destroy infected hepatocytes. One of the reasons for the chronicity of HBV infection is that it cannot effectively activate adoptive immunity and the function of virus specific immune cells is exhausted. Among them, virus antigens (including HBV surface antigen, e antigen, core antigen, etc.) can inhibit the function of immune cells and induce immune tolerance. Long term nucleos(t)ide analogues (NAs) treatment and inactive HBsAg carriers with low HBsAg level may "wake up" immune cells with abnormal function due to the decrease of viral antigen level in blood and liver, and the specific immune function of HBV will recover to a certain extent, thus becoming the "dominant population" for functional cure. In turn, the functional cure will further promote the recovery of HBV specific immune function, which is also the theoretical basis for complete cure of hepatitis B. In the future, the complete cure of chronic HBV infection must be the combination of three drugs: inhibiting virus replication, reducing surface antigen levels and specific immune regulation, among which specific immunotherapy is indispensable. Here we review the relationship, mechanism and clinical significance between the cure of hepatitis B and immune system.

Current treatment of chronic hepatitis B: Clinical aspects and future directions

Hepatitis B virus (HBV) infection is a public health threat worldwide, and there is no direct treatment yet available. In the event of infection, patients may present liver cirrhosis and cancer, which threaten the patients’ health globally, especially in the Asia-Pacific region and China. In 2019, Chinese hepatopathologists updated the 2015 Guidelines for the Prevention and Treatment of Chronic Hepatitis B as the clinical reference. The other versions formulated by the American Association for the Study of Liver Diseases (2018 AASLD guidelines) (AASLD, 2018), European Association for the Study of the Liver (2017 EASL guidelines) (EASL, 2017), and Asian-Pacific Association for the Study of the Liver (2015 APASL guidelines) (APASL, 2015) also provide clinical guidance. However, there are still some issues that need to be addressed. In the present study, the following aspects will be introduced successively: (1) Who should be treated in the general population according to the guidelines; (2) Treatment of specific populations infected with HBV; (3) Controversial issues in clinical practice; (4) Perspective.

Review article: novel biomarkers in hepatitis B infection

BACKGROUND

Chronic hepatitis B remains a global health problem with an estimated 296 million people affected worldwide. Individuals are at risk of serious complications such as cirrhosis and hepatocellular carcinoma and accurately predicting these clinical endpoints has proven difficult. However, several viral biomarkers have recently been developed, including quantitative HBV surface antigen (qHBsAg), hepatitis B RNA (HBV RNA) and core-related antigen (HBcrAg), and shown promise in a range of clinical settings.

AIMS

To critically appraise these novel biomarkers, exploring their potential uses, availability of assays and areas for future development.

METHODS

We performed a literature search of PubMed, identifying articles published in the field of hepatitis B biomarkers between 2010 and 2022.

RESULTS

Novel biomarkers such as HBcrAg, HBV RNA and qHBsAg may be useful in predicting treatment outcomes, stratifying the risk of future complications and estimating off-treatment viral reactivation. Furthermore, HBV RNA and HBcrAg titres may accurately reflect cccDNA transcriptional activity, and this is particularly informative in the context of nucleoside analogue therapy. On a cautionary note, most studies have been performed in Caucasian or Asian populations, and methods for detecting HBV RNA lack standardisation.

CONCLUSION

Novel viral biomarkers have the potential to provide additional insights into the natural history of infection and allow a more bespoke, cost-effective framework of care. However, access remains limited, and further efforts are needed to validate their use in ethnically diverse populations, confirm predictive cut-off values, and establish their role in the era of novel antiviral therapies.

Importance of quantitative HBsAg detection in whole course management of patients with chronic hepatitis B

HBsAg is the earliest known serum marker for hepatitis B virus (HBV). It plays an important role in the pathogenesis, diagnosis, and prevention of chronic hepatitis B (CHB). In the era of antiviral therapy, the concept of functional cure is put forward. HBsAg, as an old marker of HBV infection, has been found to have more and more new applications in the management of CHB patients. Positive HBsAg is taken as the indication of antiviral treatment in special CHB patients. The level of HBsAg is conducive to the selection of treatment regimens, and the dynamics of HBsAg is conducive to the adjustment of treatment scheme. HBsAg level and its kinetics can predict the therapeutic effect and disease outcome, and guide drug withdrawal. Further research is needed on the sensitivity of HBsAg, its impact on long-term outcomes, and its value in functional cure and complete cure.

Diversity of the nucleic acid forms of circulating HBV in chronically infected patients and its impact on viral cycle

BACKGROUND

Besides the prototypical hepatitis B virus (HBV) infectious particle, which contains a full-length double-stranded DNA (flDNA), additional circulating virus-like particles, which carry pregenomic RNA (pgRNA), spliced1RNA (sp1RNA) or spliced-derived DNA (defDNA) forms have been described. We aimed to determine the level of these four circulating forms in patients and to evaluate their impact on viral lifecycle.

METHODS

Chronic HBV untreated patients (n = 162), included in the HEPATHER cohort, were investigated. Pangenomic qPCRs were set up to quantify the four circulating forms of HBV nucleic acids (HBV_naf). In vitro infection assays were performed to address the impact of HBV_naf.

RESULTS

Hierarchical clustering individualized two clusters of HBV_naf diversity among patients: (1) cluster 1 (C1) showing a predominance of flDNA; (2) cluster 2 (C2) showing various proportions of the different forms. HBeAg-positive chronic hepatitis phase and higher viral load (7.0 ± 6.4 vs 6.6 ± 6.2 Log₁₀ copies/ml; p < 0.001) characterized C2 compared to C1 patients. Among the different HBV_naf, pgRNA was more prevalent in C1 patients with high vs low HBV viral load (22.1% ± 2.5% vs 4.1% ± 1.8% of HBV_naf, p < 0.0001) but remained highly prevalent in C2 patients, whatever the level of replication. C2 patients samples used in infection assays showed that: (1) HBV_naf secretion was independent of the viral strain; (2) the viral cycle efficiency differed according to the proportion of HBV_naf in the inoculum, independently of cccDNA formation. Inoculum enrichment before infection suggests that pgRNA-containing particles drive this impact on viral replication.

CONCLUSION

Besides the critical role of HBV replication in circulating HBV_naf diversity, our data highlight an impact of this diversity on the dynamics of viral cycle.

CLINICAL TRIAL REGISTRATION

Patients were included from a prospective multicenter French national cohort (ANRS CO22 HEPATHER, NCT01953458).

Serum Pregenomic RNA Combined With Hepatitis B Core-Related Antigen Helps Predict the Risk of Virological Relapse After Discontinuation of Nucleos(t)ide Analogs in Patients With Chronic Hepatitis B

BACKGROUND AND AIM

Cessation of nucleos(t)ide analogs (NAs) therapy in patients with chronic hepatitis B (CHB) is uncommon. Although criteria for discontinuation appear in some guidelines, the indicators for assessing discontinuation of NAs are limited, whether NAs can be safely ceased remains a difficult clinical issue. Our study aimed to investigate the role of serum pregenomic RNA (pgRNA) and hepatitis B core-related antigen (HBcrAg) at the end of treatment (EOT) in guiding the safe discontinuation of NAs in CHB patients.

METHODS

This is a retrospective study, clinical data of all CHB patients who discontinued NAs treatment at West China Hospital between June 2020 and January 2021 were collected, including EOT pgRNA, HBcrAg, hepatitis B surface antigen (HBsAg), etc. All patients should meet the Asian-Pacific guideline for discontinuation. Observing virological relapse (VR) rates during 1 year of NAs discontinuation and analyzing the relationship between EOT pgRNA, HBcrAg, and VR.

RESULTS

A total of 64 patients were enrolled in this study and 33 (51.5%) patients experienced VR in 1 year. EOT pgRNA positivity (OR = 14.59, p = 0.026) and EOT higher HBcrAg levels (OR = 14.14, p = 0.001) were independent risk factors for VR. The area under the receiver-operating characteristic (AUROC) value of EOT HBcrAg for VR was 0.817 (p < 0.001), optimal cut-off value was 3.3 log10 U/mL. Patients with EOT pgRNA positivity and EOT HBcrAg >3.3 log10 U/mL were more likely to experience VR after discontinuation of NAs (88.9 vs. 45.5%, p = 0.027).

CONCLUSION

According to current guidelines, a higher VR rate occurs after cessation of NAs. EOT pgRNA positivity and higher HBcrAg level carries a higher risk of VR. Combining these novel markers can better help us assess whether patients can safely cease NAs treatment.

Combining the HBcrAg decline and HBV mutations predicts spontaneous HBeAg seroconversion in chronic hepatitis B patients during the immune clearance phase

OBJECTIVE

To assess predictive ability of hepatitis B virus (HBV) markers and genome mutations for spontaneous hepatitis B e antigen (HBeAg) seroconversion.

METHODS

A total of 113 chronic hepatitis B (CHB) patients were followed up for 76 weeks without antiviral treatment. Baseline basal core promoter (BCP) and precore mutations were detected and serum hepatitis B surface antigen (HBsAg), HBeAg, hepatitis B core-related antigen (HBcrAg) and HBV DNA levels were serially quantified.

RESULTS

Eighteen patients experienced spontaneous HBeAg seroconversion (Group A), and the left 95 patients did not experience spontaneous HBeAg seroconversion (Group B). At week 28, HBsAg (P=0.03) and HBcrAg (P=0.01) levels were significantly different between Group A and B. Reduced HBsAg (P=0.02) and HBcrAg (P<0.01) levels from baseline to week 28 were significantly different between two groups. Multivariate logistic regression showed that lower HBcrAg (OR=1.02, P=0.03) levels at week 28, and HBcrAg levels with sharp decrease at week 28 (OR=0.19, P=0.02) were related with spontaneous HBeAg seroconversion. The areas under the receiver operating characteristic curve (AUROC) showed that reduction in HBcrAg levels from baseline to week 28 (0.93, P=0.001, 95% CI: 0.74-1.08) have excellent prediction value. The mutation frequencies of A1574T (51.11% vs 18.18%, P=0.001), G1862A (30.00% vs 13.03%, P=0.001), G1896A (27.22% vs 5.45%, P=0.001) and C1913G (32.78% vs 12.73%, P=0.001) in Group A were significantly higher than Group B.

CONCLUSIONS

Baseline A1574T, G1862A, G1896A and C1913G mutations and HBcrAg levels with sharp decrease at week 28 were associated with spontaneous HBeAg seroconversion. This article is protected by copyright. All rights reserved.