Baseline hepatitis B surface antigen (HBsAg) levels are associated with the likelihood of achieving HBsAg loss which defines the functional cure. However, optimal HBsAg cut-offs for predicting HBsAg loss have not been systematically investigated." Therefore, in this systematic review and meta-analysis, we evaluated the impact of baseline levels of HBsAg on achieving a functional cure in patients with chronic hepatitis B (CHB).

We searched PubMed, Embase, and Cochrane Library up to December 31, 2023, to identify studies comparing combination therapy with nucleos(t)ide analogues (NAs) and conventional/pegylated interferon (IFN) versus monotherapy. We pooled the proportion of HBsAg loss among studies stratified by different 75th percentile of baseline HBsAg levels and other clinical characteristics.

We included 24 studies with 3446 participants. At the end of treatment, studies recruiting patients with 75th percentile of baseline HBsAg below 500 and 1000 IU/mL had the highest proportions of HBsAg loss in the combination group, reaching 14 % (95 % CI: 9-21 %) and 17 % (95 % CI: 10-24 %), respectively. One-year IFN-NAs combination treatment achieved a higher proportion of HBsAg loss (9 %, 95 % CI: 6-12 %) than six-month IFN-NAs treatment (1 %, 95 % CI: 0-2 %). Patients with normal alanine transaminase (ALT) had higher HBsAg loss (11 %, 95 % CI: 6-17 %) than those with elevated ALT (4 %, 95 % CI: 2-7 %). Meta-regression indicated a positive association between male percentage in studies and HBsAg loss.

The optimal baseline HBsAg thresholds would be 500-1000 IU/mL, which represents high-response subpopulation for achieving functional cure with currently available therapy.

Aims/Background Hepatitis B virus (HBV) infection poses a challenge to global healthcare. Peginterferon alfa-2b (PEG-IFNα-2b) is an effective treatment for HBV infection. This study aimed to explore the efficacy of PEG-IFNα-2b combined with entecavir in the treatment of HBV infection, its effect on liver function and immune factors, and the risk factors affecting the prognosis of patients with HBV infection. Methods The clinical data of 184 patients with HBV infection who were treated at Jinhua Central Hospital from January 2021 to January 2024 were collected for retrospective analysis. Patients were divided into a control group (not receiving antiviral treatment, n = 34), a standard treatment group (receiving entecavir, n = 85), and a combination treatment group (PEG-IFNα-2b and entecavir, n = 65) according to the treatment approach. Treatment efficacy, liver function indicators (albumin [ALB], alanine aminotransferase [ALT], and aspartate aminotransferase [AST]), immune factor indexes (tumour necrosis factor alpha [TNF-α] and interferon gamma [IFN-γ]), hepatitis B surface antigen [HBsAg] and HBV DNA levels were compared among the three groups. All patients were followed up after treatment. According to their prognosis, the patients were divided into good prognosis group (n = 118) and poor prognosis group (n = 66). Logistic regression analysis was performed to explore the risk factors affecting the prognosis of HBV patients. Results The efficacy in the combination treatment group was higher (92.31%) than that in the control group (8.82%) and the standard treatment group (78.82%) (p < 0.05). After treatment, the HBsAg and HBV DNA levels were decreased in the standard treatment and combination treatment groups (p < 0.05). Compared with the control and standard treatment groups, the combination treatment group exhibited significantly lower HBsAg and HBV DNA levels after treatment (p < 0.05). Besides, the combination treatment group had lower ALT and AST levels (p < 0.05), and higher ALB level (p < 0.05), than the control and standard treatment groups after treatment. Compared with the control and standard treatment groups, the combination treatment group demonstrated decreased TNF-α level and higher IFN-γ level after treatment (p < 0.05). Multivariate logistic regression analysis identified family medical history as the risk factor affecting the prognosis of patients with HBV infection (p = 0.001, odds ratio [OR] = 3.614, 95% confidence interval [CI]: 1.685-7.750) and therapy regimen as the protective factor (p = 0.029, OR = 0.135, 95% CI: 0.022-0.815). Conclusion The PEG-IFNα-2b combination therapy in patients with HBV infection significantly improves the clinical treatment efficacy, liver function, and immune factors. In addition, this study found that therapy regimen and family medical history are independent factors affecting the prognosis of HBV infection.

As new evidence emerges, treatment strategies toward the functional cure of chronic hepatitis B are evolving. In 2019, a panel of national hepatologists published a Consensus Statement on the functional cure of chronic hepatitis B. Currently, an international group of hepatologists has been assembled to evaluate research since the publication of the original consensus, and to collaboratively develop the updated statements. The 2.0 Consensus was aimed to update the original consensus with the latest available studies, and provide a comprehensive overview of the current relevant scientific literatures regarding functional cure of hepatitis B, with a particular focus on issues that are not yet fully clarified. These cover the definition of functional cure of hepatitis B, its mechanisms and barriers, the effective strategies and treatment roadmap to achieve this endpoint, in particular new surrogate biomarkers used to measure efficacy or to predict response, and the appropriate approach to pursuing a functional cure in special populations, the development of emerging antivirals and immunomodulators with potential for curing hepatitis B. The statements are primarily intended to offer international guidance for clinicians in their practice to enhance the functional cure rate of chronic hepatitis B.

Serum hepatitis B surface antigen (HBsAg) < 100 IU/mL has been recently proposed as one of the key criteria of 'partial cure' in patients with chronic hepatitis B virus (HBV) infection. We analysed the clinical prognosis of hepatitis B e antigen (HBeAg)-negative untreated patients with HBsAg < 100 IU/mL and normal alanine aminotransferase (ALT) levels.

Five hundred and twenty-one untreated patients with HBeAg negativity, HBsAg < 100 IU/mL and normal ALT levels were included from three hospitals. Spontaneous HBsAg seroclearance, phase transition, liver fibrosis progression and hepatocellular carcinoma (HCC) development were analysed.

The median age was 43.0 years, and 62.2% of the patients were male. After a median follow-up of 25.0 months, 52 (10.0%) patients achieved spontaneous HBsAg seroclearance. The annual HBsAg seroclearance rate is 4.2%. Patients with baseline HBsAg ≤ 10 IU/mL (adjusted hazard ratio [aHR] = 3.490, p < 0.001) and male sex (aHR = 1.980, p = 0.041) were more likely to achieve HBsAg seroclearance. Only 4 (0.8%) and 23 (4.8%) patients transitioned to the immune escape phase and HBeAg-negative indeterminate phase, respectively. Baseline serum HBsAg > 10 IU/mL (aHR = 3.846, p = 0.034) and detectable HBV DNA (aHR = 2.672, p = 0.023) were associated with transition to the HBeAg-negative indeterminate phase. No patient developed HCC or had fatal outcomes.

HBeAg-negative patients with serum HBsAg < 100 IU/mL and normal ALT levels had a favourable prognosis. HBsAg ≤ 10 IU/mL and male sex were associated with a higher rate of HBsAg seroclearance, while HBsAg > 10 IU/mL and detectable HBV DNA were associated with a higher risk of transition to the indeterminate phase.

Human hepatitis B virus (HBV) infection is the major cause of acute and chronic hepatitis B, liver cirrhosis, and hepatocellular carcinoma. Although the application of prophylactic vaccination programs has successfully prevented the trend of increasing HBV infection prevalence, the number of HBV-infected people remains very high. Approved therapeutic management efficiently suppresses viral replication; however, HBV infection is rarely completely resolved. The major reason for therapeutic failure is the persistence of covalently closed circular DNA (cccDNA), which forms viral minichromosomes by combining with histone and nonhistone proteins in the nucleus. Increasing evidence indicates that chromatin-modifying enzymes, viral proteins, and noncoding RNAs are essential for modulating the function of cccDNA. Therefore, a deeper understanding of the regulatory mechanism underlying cccDNA transcription will contribute to the development of a cure for chronic hepatitis B. This review summarizes the current knowledge of cccDNA biology, the regulatory mechanisms underlying cccDNA transcription, and novel anti-HBV approaches for eliminating cccDNA transcription.

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.

Serum hepatitis B surface antigen (HBsAg) level < 100 IU/ml and undetectable hepatitis B virus (HBV) DNA have been recently proposed as an alternate endpoint of "partial cure" in chronic hepatitis B (CHB). We investigated clinical outcomes of hepatitis B e antigen (HBeAg)-negative CHB patients with HBsAg <100 IU/ml and undetectable HBV DNA. Treatment-naïve HBeAg-negative CHB patients with undetectable HBV DNA and normal alanine aminotransferase were retrospectively included from three institutions. Patients were classified into the low HBsAg group (<100 IU/ml) and the high HBsAg group (≥100 IU/ml). Liver fibrosis was evaluated by noninvasive tests (NITs). A total of 1218 patients were included and the median age was 41.5 years. Patients with low HBsAg were older (45.0 vs. 40.0 years, P < 0.001) than those in the high HBsAg group, while the NIT parameters were comparable between groups. During a median follow-up of 25.7 months, patients with low HBsAg achieved a higher HBsAg clearance rate (13.0% vs. 0%, P < 0.001) and a lower rate of significant fibrosis development (2.2% vs. 7.0%, P = 0.049) compared to patients with high HBsAg. No patient developed HCC in either group. HBsAg level was negatively associated with HBsAg clearance (HR 0.213, P < 0.001) and patients with HBsAg < 100 IU/ml had a low risk of significant fibrosis development (HR 0.010, P = 0.002). The optimal cutoff value of HBsAg for predicting HBsAg clearance was 1.1 Log10 IU/ml. Treatment-naïve HBeAg-negative CHB patients with HBsAg <100 IU/ml and undetectable HBV DNA had favourable outcomes with a high rate of HBsAg clearance and a low risk of fibrosis progression.

Little is known for factors associated with virologic breakthrough (VBT) after switching from nucleos(t)ide analogue (NA) to pegylated interferon alpha (Peg-IFN-α) for patients with chronic hepatitis B (CHB). Eighty patients who received 48-week Peg-IFN-ɑ and NA combination therapy followed by Peg-IFN-ɑ monotherapy for additional 48 weeks were included in this study. HBV-related markers including HBV DNA, HBsAg, HBcrAg, HBeAg, cccDNA, and immunological biomarkers were dynamically evaluated. Twelve (15.0%) patients experienced VBT after switching to Peg-IFN-ɑ and exhibited significantly lower rates of HBsAg loss after therapy completion (0% vs. 35.3%, p = 0.014). The patients with HBcrAg≥ 5 log10U/mL and HBsAg≥ 100 IU/mL had the highest risk of VBT and failed to achieve subsequent HBsAg clearance. Intrahepatic cccDNA level was significantly higher in patients with HBcrAg≥ 5 log10U/mL than those with HBcrAg< 5 log10U/mL. Notably, in contrast to patients with HBcrAg< 5 log10U/mL or with HBsAg< 100 IU/mL who had obviously restored HBV-specific CD8+T cell, Tfh or B cell responses before NA cessation, those with HBcrAg≥ 5 log10U/mL or with HBsAg≥ 100 IU/mL exhibited lackluster immunities before NA cessation and notable diminished immune responses thereafter. Monitoring HBcrAg and HBsAg levels, which correlated with poor immune responses during sequential Peg-IFN-ɑ strategy, may help to avoid VBT and improve functional cure of CHB.

Hepatitis B surface antigen (HBsAg) loss is regarded as a pivotal criterion for assessing functional cure in patients diagnosed chronic hepatitis B (CHB). We conducted the research to investigate the real-world performance of HBsAg seroconversion in sustaining HBsAg loss.

This retrospective analysis confirmed 295 patients who attained HBsAg loss through combination therapy involving nucleos(t)ide analogues (NAs) and pegylated interferon alpha (peg-IFNα). Employing Kaplan-Meier estimates method to conduct survival analysis. The forest plot was used to visualize the results of multivariate Cox regression, and selected variables were included in the nomogram.

HBsAg seroreversion was observed in 45 patients during follow-up periods, with a lower recurrence risk in patients with HBsAg seroconversion at the end of peg-IFNα therapy (EOT) (10.3% vs 37.3% at 96-week, P < 0.0001). Moreover, the sustainability of hepatitis B surface antibody (anti-HBs) in participants continuing therapy after HBsAg seroconversion was superior to those discontinued prematurely (72.5% vs 54.5% at 96 weeks, P = 0.012). Additionally, the former group was also relatively less likely to experience HBsAg reversion during long-term observation (8.4% vs 14.3% at 96 weeks, P = 0.280). Hepatitis B envelope antigen (HBeAg) status, anti-HBs status and consolidation treatment screened by multivariable analysis were utilized to construct a predictive model for HBsAg reversion. The concordance index(C-index = 0.77) and calibration plots indicated satisfactory discrimination and consistency of nomogram.

HBsAg seroconversion was beneficial for sustaining functional cure in patients treated with peg-IFNα. Continuing consolidation therapy after HBsAg seroconversion also contributed to maintain HBsAg seroconversion and improve the durability of HBsAg loss. The nomogram illustrated its efficacy as a valuable instrument in showcasing survival probability of functional cure.

The efficacy of different pegylated interferon (PEG-IFN) treatment strategies for achieving sustained hepatitis B surface antigen (HBsAg) clearance in chronic hepatitis B (CHB) remains controversial. This study assesses the efficacy of different PEG-IFN treatment regimens and factors influencing sustained HBsAg clearance after PEG-IFN discontinuation. PubMed , Embase , Web of Science , and the Cochrane Library databases were searched from inception to June 2023, regarding PEG-IFN therapy in CHB. Methodological quality was assessed using the Cochrane risk of bias tool. We explored sources of heterogeneity through univariate meta-regression. Frequentist network meta-analyses were used to compare the efficacy of different PEG-IFN treatment strategies. We analyzed 53 studies (including 9338 CHB patients). After PEG-IFN withdrawal, the annual rates of HBsAg clearance and seroconversion were 6.9% [95% confidence interval (CI), 5.10-9.31] and 4.7% (95% CI, 2.94-7.42). The pooled 1-, 3-, and 5-year sustained HBsAg clearance rates were 7.4%, 9.9%, and 13.0%, and the sustained HBsAg seroconversion rates were 6.6%, 4.7%, and 7.8%, respectively. HBsAg quantification, hepatitis B e antigen status, and PEG-IFN treatment protocols were major sources of heterogeneity. Baseline HBsAg quantification was significantly lower in patients with sustained HBsAg clearance versus those without ( P  < 0.046). PEG-IFN combined with tenofovir has the highest probability of achieving HBsAg seroconversion (surface under the cumulative ranking of 81.9%). Sustained HBsAg clearance increased approximately linearly from years 1 to 5 after PEG-IFN discontinuation. Low baseline HBsAg quantification has a significant impact on sustained HBsAg clearance. PEG-IFN combined with tenofovir may be optimal in achieving sustained HBsAg seroconversion.

Interferon-alpha (IFNα) is a common treatment for chronic hepatitis B virus (HBV) infection, but its efficacy varies widely among patients. GTPASE, an interferon-stimulated gene (ISG), has recently been identified as a factor in antiviral immunity, though its role in HBV infection is not fully understood.

This study investigates the role of GTPASE in enhancing the antiviral effects of IFNα against HBV and elucidates its mechanism of action.

We analyzed the impact of GTPASE overexpression and silencing on HBV replication and clearance in HBV-infected cells. Molecular docking studies assessed the interaction between GTPASE and HBV surface antigens (HBs). Clinical samples from HBV patients undergoing Peg-IFNα treatment were also evaluated for GTPASE expression and its correlation with treatment efficacy.

Overexpression of GTPASE led to significant inhibition of HBV replication, increased HBeAg seroconversion, and enhanced HBsAg clearance. GTPASE directly bound to HBs proteins, reducing their levels and affecting viral particle formation. Silencing GTPASE reduced these effects, while combined treatment with Peg-IFNα and GTPASE overexpression further improved antiviral outcomes. Mutational analysis revealed that specific sites in GTPASE are crucial for its antiviral activity.

GTPASE acts as a positive regulator in IFNα-induced antiviral immunity against HBV. It enhances the therapeutic efficacy of IFNα by targeting HBs and modulating viral replication. GTPASE levels may serve as a predictive biomarker for response to Peg-IFNα therapy, highlighting its potential for improving individualized treatment strategies for chronic HBV infection.

Current treatment of chronic hepatitis B virus (HBV) infection, pegylated interferon-α (pegIFN-α) and nucleos(t)ide analogue (NA), can suppress HBV replication, reverse liver inflammation and fibrosis, and decrease risks of cirrhosis and hepatocellular carcinoma, but hepatitis B surface antigen (HBsAg) loss is rare. Functional HBV cure is defined as undetectable HBsAg and unquantifiable serum HBV DNA for at least 24 weeks after a finite course of therapy. This requires suppression of HBV replication and viral protein production as well as restoration of immune response to HBV. Direct-acting antivirals targeting virus entry, capsid assembly, viral protein production and secretion are in clinical trials. In parallel, immune modulatory therapies to stimulate HBV-specific immune response and to remove immune blockade are being tested. Clinical trials of direct-acting antivirals alone or immune modulatory therapies alone have not been successful in achieving HBV cure. Recent combinations of direct-acting antivirals and immune modulatory therapies have shown promising results particularly with combinations that included pegIFN-α. These results need to be confirmed in larger studies with longer follow-up, and further work is needed to develop simpler regimens with fewer drugs that can be administered orally and safely. While there is a strong desire to develop finite therapies that can achieve HBV cure, safety is paramount and new therapies must provide incremental value compared to standard of care, which is predominantly long-term NA therapy.

Introduction: Chronic hepatitis B (CHB) is a worldwide infectious disease caused by hepatitis B virus (HBV). Optimizing antiviral treatment strategies could improve the functional cure (FC) rate of patients with CHB. This study aims to systematically review the FC rate of the de novo combination of nucleos(t)ide analogs (NAs) and pegylated interferon α (PEG-IFNα) versus that of PEG-IFNα monotherapy for CHB. Methods: Databases were searched until 31 December 2023. Selected studies included randomized controlled trials on the de novo combination of NAs and PEG-IFNα versus PEG-IFNα monotherapy for 48 weeks in patients with CHB to achieve FC, which was defined as hepatitis B surface antigen (HBsAg) loss and/or HBsAg seroconversion. Meta-analysis was conducted in accordance with the efficacy at the end of treatment and different time points during follow-up. Results: A total of 10 studies, encompassing 2,339 patients in total, were included. Subgroup analysis was conducted in accordance with whether first-line NAs were used. It found no statistically significant difference between HBsAg loss and HBsAg seroconversion at the end of treatment. Serum HBV DNA <500 copies/mL significantly differed between the two groups at the end of treatment and did not significantly differ during follow-up. Meanwhile, HBsAg loss and HBsAg seroconversion showed statistically significant differences at 24 weeks of follow-up. By contrast, no statistically significant difference was found in HBsAg loss at 48 weeks of follow-up. Discussion: Without distinguishing the eligible preponderant population, the efficacy of the de novo combination of NAs and PEG-IFNα in treating patients with CHB was not superior to that of PEG-IFNα monotherapy. Systematic Review Registration: PROSPERO, identifier CRD42022325239.

In Mexico, hepatitis B and C infections are a significant burden on the health system. The aim of this narrative review was to analyze the state of the art on hepatitis B and C in Mexico by searching and studying available data in academic articles and government reports and statements on epidemiology, prevention, treatment, and elimination strategies undertaken by the Mexican government. Even where the government has implemented a hepatitis B vaccination strategy to reduce its incidence, a very low proportion of people complete the vaccination schedule. Regarding hepatitis C, there is a National Elimination Program that emphasizes the importance of screening, diagnosis, and treatment focused on the population at risk. With the implementation of this program, more than a million fast tests have been carried out and the positive cases have been verified by viral load. Infected patients are tested to determine liver function, fibrosis stage, and coinfection with HBV and/or HIV. Patients without cirrhosis and/or coinfections are treated in first-level care centers, while those with cirrhosis and/or comorbidities are referred to specialists. The possibility of hepatitis C eradication in Mexico seems more likely than eradication of hepatitis B; however, major challenges remain to be overcome to reach both infections' elimination.

The identification of reliable predictors for hepatitis B surface antigen (HBsAg) seroclearance remains controversial. We aimed to summarize potential predictors for HBsAg seroclearance by pegylated interferon-α (PegIFNα) in patients with chronic HBV infection.

A systematic search of the Cochrane Library, Embase, PubMed, and Web of Science databases was conducted from their inception to 28 September 2022. Meta-analyses were performed following the PRISMA statement. Predictors of HBsAg seroclearance were evaluated based on baseline characteristics and on-treatment indicators.

This meta-analysis encompasses 27 studies, including a total of 7913 patients. The findings reveal several factors independently associated with HBsAg seroclearance induced by PegIFNα-based regimens. These factors include age (OR = 0.961), gender (male vs. female, OR = 0.537), genotype (A vs. B/D; OR = 7.472, OR = 10.738), treatment strategy (combination vs. monotherapy, OR = 2.126), baseline HBV DNA (OR = 0.414), baseline HBsAg (OR = 0.373), HBsAg levels at week 12 and 24 (OR = 0.384, OR = 0.294), HBsAg decline from baseline to week 12 and 24 (OR = 6.689, OR = 6.513), HBsAg decline from baseline ≥ 1 log10 IU/ml and ≥ 0.5 log10 IU/ml at week 12 (OR = 18.277; OR = 4.530), and ALT elevation at week 12 (OR = 3.622). Notably, subgroup analysis suggests no statistical association between HBsAg levels at week 12 and HBsAg seroclearance for treatment duration exceeding 48 weeks. The remaining results were consistent with the overall analysis.

This is the first meta-analysis to identify predictors of HBsAg seroclearance with PegIFNα-based regimens, including baseline and on-treatment factors, which is valuable in developing a better integrated predictive model for HBsAg seroclearance to guide individualized treatment and achieve the highest cost-effectiveness of PegIFNα.

Chronic infection with the hepatitis B virus (HBV) induces progressive hepatic impairment. Achieving complete eradication of the virus remains a formidable challenge. Cytotoxic T lymphocytes, specific to viral antigens, either exhibit a numerical deficiency or succumb to an exhausted state in individuals chronically afflicted with HBV. The comprehension of the genesis and dissemination of stem cell memory T cells (TSCMs) targeting HBV remains inadequately elucidated. We identified TSCMs in subjects with chronic HBV infection and scrutinized their efficacy in a murine model with human hepatocyte transplants, specifically the TK-NOG mice. TSCMs were discerned in all subjects under examination. Introduction of TSCMs into the HBV mouse model precipitated a severe necro-inflammatory response, resulting in the elimination of human hepatocytes. TSCMs may constitute a valuable tool in the pursuit of a remedial therapy for HBV infection.

Interferon-alpha (IFN-α) is a first-line drug for treating chronic hepatitis B (CHB). Guanylate-binding protein 1 (GBP1) is one of the interferon-stimulating factors, which participates in the innate immunity of the host and plays an antiviral and antibacterial role. In this study, we explored how GBP1 is involved in IFN-α antiviral activity against HBV. Before being gathered, HepG2-NTCP and HepG2 2.15 cells were transfected with the wild-type hGBP1 plasmid or si-GBP1, respectively, and followed by stimulation with Peg-IFNα-2b. We systematically explored the role of GBP1 in regulating HBV infection in cell models. Additionally, we also examined GBP1 levels in CHB patients. GBP1 activity increased, and its half-life was prolonged after HBV infection. Overexpression of GBP1 inhibited the production of HBsAg and HBeAg, as well as HBs protein and HBV total RNA levels, whereas silencing of GBP1 inhibited its ability to block viral infections. Interestingly, overexpressing GBP1 co-treatment with Peg-IFNα-2b further increased the antiviral effect of IFN-α, while GBP1 silencing co-treatment with Peg-IFNα-2b partly restored its inhibitory effect on HBV. Mechanistically, GBP1 mediates the anti-HBV response of Peg-IFNα-2b by targeting HBs. Analysis of clinical samples revealed that GBP1 was elevated in CHB patients and increased with Peg-IFNα-2b treatment, while GBP1 showed good stability in the interferon response group. Our study demonstrates that GBP1 inhibits HBV replication and promotes HBsAg clearance. It is possible to achieve antiviral effects through the regulation of IFN-α induced immune responses in response to HBV.

Representatives from academia, industry, regulatory agencies, and patient advocacy groups convened under the American Association for the Study of Liver Diseases (AASLD) and the European Association for the Study of the Liver (EASL) in June 2022 with the primary goal of achieving consensus on chronic HBV and HDV treatment endpoints to guide clinical trials aiming to "cure" HBV and HDV. Conference participants reached an agreement on some key points. The preferred primary endpoint for phase II/III trials evaluating finite treatments for chronic hepatitis B (CHB) is a "functional" cure, defined as sustained HBsAg loss and HBV DNA less than the lower limit of quantitation (LLOQ) 24 weeks off-treatment. An alternate endpoint would be "partial cure" defined as sustained HBsAg level <100 IU/mL and HBV DNA Collapse

Chronic hepatitis B (CHB) is rarely cured using available treatments. Barriers to cure are: 1) persistence of reservoirs of hepatitis B virus (HBV) replication and antigen production (HBV DNA); 2) high burden of viral antigens that promote T cell exhaustion with T cell dysfunction; 3) CHB-induced impairment of immune responses.

We discuss options for new therapies that could address one or more of the barriers to functional cure, with particular emphasis on the potential role of immunotherapy.

Ideally, a sterilizing cure for CHB would translate into finite therapies that result in loss of HBV surface antigen and eradication of HBV DNA. Restoration of a functional adaptive immune response, a key facet of successful CHB treatment, remains elusive. Numerous strategies targeting the high viral DNA and antigen burden and aiming to restore the host immune responses will enter clinical development in coming years. Most patients are likely to require combinations of several drugs, personalized according to virologic and disease characteristics, patient preference, accessibility, and affordability. The management of CHB is a global health priority. Expedited drug development requires collaborations between regulatory agencies, scientists, clinicians, and within the industry to facilitate testing of the best drug combinations.

As a key immune cytokine, C-X-C motif chemokine ligand 13 (CXCL13) has been reported to play critical roles in immune control of hepatitis B virus (HBV) infection. We aimed to screen single-nucleotide polymorphisms (SNPs) of CXCL13 for predicting response to pegylated interferon-alpha (PegIFNα) therapy of chronic hepatitis B (CHB) patients. Two independent cohorts with a total of 945 (Cohort 1, n = 238; Cohort 2, n = 707) hepatitis B e antigen (HBeAg)-positive CHB patients treated with PegIFNα were enrolled in this retrospective cohort study. Eight candidate SNPs were selected through gene-wide SNP mining within or flanking CXCL13. A polygenic score (PGS) was utilized to assess the cumulative effects of multiple SNPs. The associations of candidate SNPs and PGS with combined response (CR, defined as the combination of HBeAg seroconversion and HBV DNA level <3.3log10 IU/mL) and hepatitis B surface antigen (HBsAg) level were evaluated. Among the eight candidate SNPs, rs76084459 which is located at upstream of CXCL13 was significantly associated with both CR (p = 0.002) and HBsAg level (p = 0.015). A PGS integrating CXCL13_rs76084459 and five other SNPs, which were previously identified as predictors of PegIFNα treatment response, was further strongly correlated with CR (p = 1.759 × 10-10 ) and HBsAg level (p = 0.004). This study demonstrated that CXCL13_rs76084459 can predict response to PegIFNα treatment of HBeAg-positive CHB patients. A PGS composed of six SNPs including CXCL13_rs76084459 predicts PegIFNα treatment response better.

The study aims to evaluate the effectiveness of a tenofovir alafenamide fumarate (TAF) and pegylated interferon alfa (PegIFN-α) regimen compared to a tenofovir disoproxil fumarate (TDF) and PegIFN-α therapy in patients with chronic hepatitis B (CHB).

Patients who were treated with PegIFN-α in combination with TAF or TDF were retrospectively enrolled. The primary outcome measured was the HBsAg loss rate. The rates of virological response, serological response for HBeAg, and normalization of alanine aminotransferase (ALT) were also calculated. The cumulative incidences of response rates were compared between the two groups using Kaplan-Meier analysis.

A total of 114 patients were retrospectively enrolled in the study, with 33 receiving TAF plus PegIFN-α treatment and 81 receiving TDF plus PegIFN-α treatment. The HBsAg loss rate for the TAF plus PegIFN-α group was 15.2% at 24 weeks and 21.2% at 48 weeks, while the TDF plus PegIFN-α group had rates of 7.4% at 24 weeks and 12.3% at 48 weeks (P=0.204 at 24 weeks, P=0.228 at 48 weeks). In subgroup analysis of HBeAg positive patients, the TAF group had a higher HBsAg loss rate of 25% at week 48, compared to 3.8% in the TDF group (P=0.033). According to Kaplan-Meier analysis, the TAF plus PegIFN-α group achieved virological response more quickly than the TDF plus PegIFN-α group (p=0.013). There was no statistical difference in HBeAg serological rate or ALT normalization rate.

There was no significant difference in the HBsAg loss between the two groups. However, subgroup analysis revealed that TAF plus PegIFN-α treatment had a higher HBsAg loss rate than TDF plus PegIFN-α treatment in HBeAg-positive patients. Additionally, TAF plus PegIFN-α treatment demonstrated better virological suppression for CHB patients. Therefore, TAF plus PegIFN-α treatment regimen is recommended for CHB patients who aim to achieve functional cure.

Over 296 million people are estimated to have chronic hepatitis B viral infection (CHB), and it poses unique challenges for elimination. CHB is the result of hepatitis B virus (HBV)-specific immune tolerance and the presence of covalently closed circular DNA as mini chromosome inside the nucleus and the integrated HBV. Serum hepatitis B core-related antigen is the best surrogate marker for intrahepatic covalently closed circular DNA. Functional HBV "cure" is the durable loss of hepatitis B surface antigen (HBsAg), with or without HBsAg seroconversion and undetectable serum HBV DNA after completing a course of treatment. The currently approved therapies are nucleos(t)ide analogues, interferon-alpha, and pegylated-interferon. With these therapies, functional cure can be achieved in < 10% of CHB patients. Any variation to HBV or the host immune system that disrupts the interaction between them can lead to reactivation of HBV. Novel therapies may allow efficient control of CHB. They include direct acting antivirals and immunomodulators. Reduction of the viral antigen load is a crucial factor for success of immune-based therapies. Immunomodulatory therapy may lead to modulation of the host immune system. It may enhance/restore innate immunity against HBV (as toll-like-receptors and cytosolic retinoic acid inducible gene I agonist). Others may induce adaptive immunity as checkpoint inhibitors, therapeutic HBV vaccines including protein (HBsAg/preS and hepatitis B core antigen), monoclonal or bispecific antibodies and genetically engineered T cells to generate chimeric antigen receptor-T or T-cell receptor-T cells and HBV-specific T cells to restore T cell function to efficiently clear HBV. Combined therapy may successfully overcome immune tolerance and lead to HBV control and cure. Immunotherapeutic approaches carry the risk of overshooting immune responses causing uncontrolled liver damage. The safety of any new curative therapies should be measured in relation to the excellent safety of currently approved nucleos(t)ide analogues. Development of novel antiviral and immune modulatory therapies should be associated with new diagnostic assays used to evaluate the effectiveness or to predict response.

The current treatment of chronic HBV infection, pegylated interferon-α (pegIFNα) and nucleos(t)ide analog (NA), can suppress HBV replication, reverse liver inflammation and fibrosis and reduce the risks of cirrhosis, HCC, and HBV-related deaths, but relapse is common when the treatment is stopped before HBsAg loss. There have been major efforts to develop a cure for HBV, defined as sustained HBsAg loss after a finite course of therapy. This requires the suppression of HBV replication and viral protein production and the restoration of immune response to HBV. Direct-acting antivirals targeting virus entry, capsid assembly, viral protein production and secretion are in clinical trials. Immune modulatory therapies to stimulate adaptive or innate immunity and/or to remove immune blockade are being tested. NAs are included in most and pegIFNα in some regimens. Despite the combination of 2 or more therapies, HBsAg loss remains rare in part because HbsAg can be derived not only from the covalently closed circular DNA but also from the integrated HBV DNA. Achievement of a functional HBV cure will require therapies to eliminate or silence covalently closed circular DNA and integrated HBV DNA. In addition, assays to differentiate the source of circulating HBsAg and to determine HBV immune recovery, as well as standardization and improvement of assays for HBV RNA and hepatitis B core-related antigen, surrogate markers for covalently closed circular DNA transcription, are needed to accurately assess response and to target treatments according to patient/disease characteristics. Platform trials will allow the comparison of multiple combinations and channel patients with different characteristics to the treatment that is most likely to succeed. Safety is paramount, given the excellent safety profile of NA therapy.

Worldwide, an estimated 296 million people are living with chronic hepatitis B virus (HBV) infection, with a significant risk of morbidity and mortality. Current therapy with pegylated interferon (Peg-IFN) and indefinite or finite therapy with nucleoside/nucleotide analogues (Nucs) are effective in HBV suppression, hepatitis resolution, and prevention of disease progression. However, few achieve hepatitis B surface antigen (HBsAg) loss (functional cure), and relapse often occurs after the end of therapy (EOT) because these agents have no direct effect on durable template: covalently closed circular DNA (cccDNA) and integrated HBV DNA. Hepatitis B surface antigen loss rate increases slightly by adding or switching to Peg-IFN in Nuc-treated patients and this loss rate greatly increases up to 39% in 5 years with finite Nuc therapy with currently available Nuc(s). For this, great effort has been made to develop novel direct-acting antivirals (DAAs) and immunomodulators. Among the DAAs, entry inhibitors and capsid assembly modulators have little effect on reducing HBsAg levels; small interfering RNA, antisense oligonucleotides, and nucleic acid polymers in combination with Peg-IFN and Nuc may reduce HBsAg levels significantly, even a rate of HBsAg loss sustained for > 24 weeks after EOT up to 40%. Novel immunomodulators, including T-cell receptor agonists, check-point inhibitors, therapeutic vaccines, and monoclonal antibodies may restore HBV-specific T-cell response but not sustained HBsAg loss. The safety issues and the durability of HBsAg loss warrant further investigation. Combining agents of different classes has the potential to enhance HBsAg loss. Compounds directly targeting cccDNA would be more effective but are still in the early stage of development. More effort is required to achieve this goal.

In the era of antiviral therapy, the main goal of treatment has shifted from the persistent inhibition of hepatitis B virus (HBV) replication to the pursuit of serological clearance of HBs surface antigen (HBsAg). Based on the life cycle of HBV, HBsAg originates from covalently closed circular DNA (cccDNA) and integrated HBV DNA, thus reflecting their transcriptional activity. Complete HBsAg loss may mean elimination or persistent inactivity of the HBV genome including cccDNA and integrated HBV DNA. HBsAg loss improves the recovery of abnormal immune function, which in turn, may further promote the clearance of residual viruses. Combined with functional cure and the great improvement of clinical outcomes, the continuous seroclearance of high-sensitivity quantitative HBsAg may represent the complete cure of chronic hepatitis B (CHB). For many other risk factors besides HBV itself, patients with HBsAg loss still need regular monitoring. In this review, we summarized the evolution of CHB treatment, the origin of serum HBsAg, the pattern of HBsAg seroclearance, and the effect of HBsAg loss on immune function and disease outcomes. In addition, we discuss the significance of high-sensitivity HBsAg detection and its possibility as a surrogate of complete cure.

As a tribute to Dr Mike Bray, the following review of literature willbe mainly based on published data andconcepts, but will also contain my personal views, and in this respect could be more considered as a bioassay. Even though a cost-effective and excellent prophylactic vaccine exists since many years to protect against hepatitis B virus (HBV) infection, academic-researcher/drug-developers/stakeholders are still busy with the R&D of novel therapies that could eventually have an impact on its worldwide incidence. The Taiwanese experience have univocally demonstrated the effectiveness of constrained national HBV prophylactic vaccination programs to prevent the most dramatic HBV-induced end-stage liver disease, which is hepatocellular carcinoma; but yet the number of individuals chronically infected with the virus, for whom the existing prophylactic vaccine is no longer useful, remains high, with around 300 million individuals around the globe. In this review/bioassay, recent findings and novel concepts on prospective therapies against HBV infections will be discussed; yet it does not have the pretention to be exhaustive, as "pure immunotherapeutic concepts" will be mainly let aside (or referred to other reviews) due to a lack of expertise of this writer, but also due to the lack of, or incremental, positive results in clinical trials as-off today with these approaches.

Functional cure of chronic hepatitis B (CHB) - or hepatitis B surface antigen (HBsAg) loss after 24 weeks off therapy - is now the goal of treatment, but is rarely achieved with current therapy. Understanding the hepatitis B virus (HBV) life cycle and immunological defects that lead to persistence can identify targets for novel therapy. Broadly, treatments fall into three categories: those that reduce viral replication, those that reduce antigen load and immunotherapies. Profound viral suppression alone does not achieve quantitative (q)HBsAg reduction or HBsAg loss. Combining nucleos(t)ide analogues and immunotherapy reduces qHBsAg levels and induces HBsAg loss in some patients, particularly those with low baseline qHBsAg levels. Even agents that are specifically designed to reduce viral antigen load might not be able to achieve sustained HBsAg loss when used alone. Thus, rationale exists for the use of combinations of all three therapy types. Monitoring during therapy is important not just to predict HBsAg loss but also to understand mechanisms of HBsAg loss using viral and immunological biomarkers, and in selected cases intrahepatic sampling. We consider various paths to functional cure of CHB and the need to individualize treatment of this heterogeneous infection until a therapeutic avenue for all patients with CHB is available.

To investigate the effect and its mechanisms of different antiviral agents on the immunogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in patients with chronic hepatitis B (CHB).

A total of 125 patients with CHB receiving nucleos(t)ide analogs (NAs) monotherapy or combined with Peg-interferon-alpha (Peg-IFNα) therapy and 29 healthy controls (HCs) were enrolled. Adverse reactions (ADRs) and levels of neutralizing antibody (NAb), immunoglobulin G (IgG), immunoglobulin M (IgM), and peripheral cytokines post-vaccination were analyzed.

All ADRs were tolerable in CHB patients. Overall, no significant difference was observed in the antibody levels between patients and HCs after two doses of vaccination. An inverse correlation between NAb, IgG titers and the days after two doses was found in non-IFN group but not in IFN group. Correspondingly, peripheral interferon-γ levels were significantly higher in IFN group than in non-IFN group. After a booster dose, NAb and IgG antibodies were maintained at high levels in NA-treated patients.

Peg-interferon-alpha-based therapy may be beneficial for maintaining the immunogenicity of SARS-CoV-2 vaccines in CHB patients, which may be related to the high levels of IFN-γ induced by Peg-IFNα therapy. A booster dose can effectively recall the robust and long-lasting immunogenicity of SARS-CoV-2 vaccines.

Hepatitis B surface antigen (HBsAg) clearance, indicating functional cure or resolved chronic hepatitis B (CHB), remains difficult to achieve via nucleos(t)ide analogue monotherapy. We investigated whether metformin add-on therapy could help achieve this goal in entecavir-treated patients with hepatitis B e antigen (HBeAg)-negative CHB.

Patients with HBeAg-negative CHB who met eligibility criteria (entecavir treatment for &gt; 12 months, HBsAg &lt; 1000 IU/mL) were randomly assigned (1:1) to receive 24 weeks of either metformin (1000 mg, oral, once a day) or placebo (oral, once a day) add-on therapy. The group allocation was blinded for both patients and investigators. Efficacy and safety analyses were based on the intention-to-treat set. The primary outcome, serum HBsAg level (IU/mL) at weeks 24 and 36, was analysed using mixed models.

Sixty eligible patients were randomly assigned to the metformin (n = 29) and placebo (n = 31) groups. There was no substantial between-group difference in the HBsAg level at week 24 (adjusted mean difference 0.05, 95% confidence interval -0.04 to 0.13, p = 0.278) or week 36 (0.06, -0.03 to 0.15, p = 0.187), and no significant effect of group-by-time interaction on the HBsAg level throughout the trial (p = 0.814). The occurrence of total adverse events between the two groups was comparable (9 [31.0%] of 29 vs. 5 [16.1%] of 31, p = 0.227) and no patient experienced serious adverse events during the study.

Although it was safe, metformin add-on therapy did not accelerate HBsAg clearance in entecavir-treated patients with HBeAg-negative CHB.

The strategies of adding on or switching to peginterferon (PEG-IFN) improved the serological response rates in patients with chronic hepatitis B (CHB) who had previously experienced treatment with nucleos(t)ide analogues. However, robust data on which combination strategy is more effective remain lacking.

In this multicentre, parallel, open-label, randomised, controlled trial, patients with HBeAg-positive CHB who were treated with entecavir ≥2 years, and had hepatitis B surface antigen (HBsAg) <3000 IU/ml, HBeAg <200S/CO and HBV DNA <50 IU/ml were randomly assigned in a 1:1:1 ratio to add on PEG-IFN, switch to PEG-IFN or continue entecavir monotherapy for 48 weeks. The primary endpoint was HBeAg seroconversion at week 48.

A total of 153 patients were randomised into three treatment arms (50 in add-on, 52 in switch-to and 51 in monotherapy). Compared with continuous entecavir monotherapy, both add-on and switch-to strategies achieved higher rates of HBeAg seroconversion (18.0% vs. 2.0%, p = 0.007; 19.2% vs. 2.0%, p = 0.005, respectively), HBeAg loss (24.0% vs. 5.9%, p = 0.010; 23.1% vs. 5.9%, p = 0.013, respectively), HBsAg < 100 IU/ml (30.0% vs. 0%, p < 0.001; 34.6% vs. 0%, p < 0.001, respectively), and higher HBsAg reduction (-0.90 vs. -0.06 log₁₀ IU/ml, p < 0.001; -0.92 vs. -0.06 log₁₀ IU/ml, p < 0.001, respectively) at week 48. The efficacy was comparable between add-on and switch-to arms (p > 0.05). Adverse events were mainly related to PEG-IFN but generally tolerable.

In patients with CHB who achieved virological response with long-term entecavir, both adding on and switching to PEG-IFN are alternative strategies resulting in higher rates of HBeAg seroconversion and HBsAg reduction than continuous entecavir.

Chinese Clinical Trial Registry (www.chictr.org.cn, identifier: ChiCTR-IPR-17012055).

Functional cure of hepatitis B is defined as sustained undetectable circulating HBsAg and HBV DNA after a finite course of treatment. Barriers to HBV cure include the reservoirs for HBV replication and antigen production (covalently closed circular DNA [cccDNA] and integrated HBV DNA), the high viral burden (HBV DNA and HBsAg) and the impaired host innate and adaptive immune responses against HBV. Current HBV therapeutics, 1 year of pegylated-interferon-α (PEG-IFNα) and long-term nucleos(t)ide analogues (NUCs), rarely achieve HBV cure. Stopping NUC therapy may lead to functional cure in some Caucasian patients but rarely in Asian patients. Switching from a NUC to IFN after HBV DNA suppression increases the chance of HBsAg clearance mainly in those with low HBsAg levels. Novel antiviral strategies that inhibit viral entry, translation and secretion of HBsAg, modulate capsid assembly, or target cccDNA transcription/degradation have shown promise in clinical trials. Novel immunomodulatory approaches including checkpoint inhibitors, metabolic modulation of T cells, therapeutic vaccines, adoptive transfer of genetically engineered T cells, and stimulation of innate and B-cell immune responses are being explored. These novel approaches may be further combined with NUCs or PEG-IFNα in personalised strategies, according to virologic and disease characteristics, to maximise the chance of HBV cure. The development of curative HBV therapies should be coupled with the development of standardised and validated virologic and immunologic assays to confirm target engagement and to assess response. In addition to efficacy, curative therapies must be safe and affordable to meet the goal of global elimination of hepatitis B.

The long-term benefits of interferon-α (IFN-α) treatment in children with chronic hepatitis B (CHB) remain unclear. We conducted a retrospective and real-world study to evaluate the safety and long-term clearance rates of hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) in CHB children who received IFN-α monotherapy for 72 weeks and were with 13-year follow-up visit. Participants treated with IFN-α (n = 316) were more likely to become HBeAg negatve (39.87% vs. 27.37%; p < .05) and HBsAg negative (11.08% vs. 3.16%; p < .05) by the end of the treatment period than untreated participants (n = 95). Treated participants also had higher cumulative rates of HBeAg loss (74.13% vs. 59.27%; p < .05) and HBsAg loss (46.95 vs. 33.11%; p < 0.05) than untreated participants in parallel by the end of 13-year follow-up. In particular, the cumulative rate of HBsAg loss was higher in treated children aged 1-7 years than in those aged 8-17 years (71.40% vs. 39.0%; p < .01). Children who were HBeAg-negative at the end of IFN-α treatment or who had serum alanine aminotransferase levels of ≥80 IU/L at baseline were likely to have higher cumulative HBsAg loss rates. Accordingly, HBeAg loss at 72 weeks was positively associated with the cumulative HBsAg loss rate in untreated children. There were no serious adverse events of IFN-α therapy for the treated patients throughout the study period. Overall, IFN-α therapy was effective in obtaining higher long-term cumulative rates of HBeAg and HBsAg loss in children with HBeAg-positive immune-active CHB, especially among those aged 1-7 years.