The updated EASL Clinical Practice Guidelines on the management of hepatitis B virus (HBV) infection provide comprehensive, evidence-based recommendations for its management. Spanning ten thematic sections, the guidelines address diagnostics, treatment goals, treatment indications, therapeutic options, hepatocellular carcinoma surveillance, management of special populations, HBV reactivation prophylaxis, post-transplant care, HBV prevention strategies, and finally address open questions and future research directions. Chronic HBV remains a global health challenge, with over 250 million individuals affected and significant mortality due to cirrhosis and hepatocellular carcinoma. These guidelines emphasise the importance of early diagnosis, risk stratification based on viral and host factors, and tailored antiviral therapy. Attention is given to simplified algorithms, vaccination, and screening to support global HBV elimination targets. The guidelines also discuss emerging biomarkers and evolving definitions of functional and partial cure. Developed through literature review, expert consensus, and a Delphi process, the guidelines aim to equip healthcare providers across disciplines with practical tools to optimise HBV care and outcomes worldwide.

Alanine aminotransferase (ALT) frequently elevates in chronic hepatitis B patients stopping nucleos(t)ide analogs (NAs).

To clarify the association between ALT elevation and HBsAg seroclearance after NA withdrawal.

This multicenter cohort study reviewed consecutive patients discontinuing NA between 2004/04/01 and 2022/05/24. Treatment initiation and discontinuation generally followed the Asian-Pacific guidelines. Eligible patients had negative HBeAg and undetectable HBV DNA before treatment cessation, without malignancy, organ transplant or autoimmune disorders. We used competing risk analysis to estimate HBsAg seroclearance incidence and a time-dependent model to investigate post-cessation ALT elevation.

Among 841 patients (74.7% male; median age, 53.2 years; median treatment duration, 34.7 months), 38 patients cleared HBsAg over a median follow-up of 3.7 years, with a 10-year cumulative incidence of 12.4%. The median peak ALT level was significantly lower in patients achieving HBsAg seroclearance versus not (93 vs. 127 U/L; p < 0.001). Hepatitis flare after NA cessation (> 5 times upper limit) was inversely associated with HBsAg seroclearance in the univariable analysis (sub-distribution hazard ratio [SHR], 0.31; 95% confidence interval [CI], 0.13-0.73; p = 0.007), and the association was not significant (adjusted SHR, 0.42; 95% CI, 0.09-2.01; p = 0.28) in the multivariable analysis adjusted for pretreatment HBV DNA. Consistent results were observed in the sensitivity analyses with different ALT cutoffs and subgroup analysis adjusted for HBsAg levels at treatment cessation.

ALT elevation after NA cessation is not associated with HBsAg seroclearance following NA withdrawal, suggesting cytolytic pathways are not essential for a functional cure.

The costimulatory molecules OX40 and OX40L, members of the tumor necrosis factor (receptor) superfamily, play an important role in viral control through the activation of T cells. We speculate that activating the immune checkpoint OX40 may promote the inhibition of hepatitis B virus (HBV) replication.

To test this hypothesis, we investigated the expression dynamics of OX40/OX40L and studied the effects of activation of OX40 on HBV replication, and further explored the possible mechanism.

We found that the percentage of T cells expressing OX40 was lower in adult patients with chronic hepatitis B (CHB) than in healthy adults and was negatively correlated with serum viral load. In contrast, the percentage of B cells and monocytes expressing OX40L was increased in adult patients with CHB and positively correlated with liver inflammatory indicators. The expression of OX40 in T cells and OX40L in monocytes was positively correlated with age in healthy donors. In addition, the levels of serum HBsAg and intrahepatic HBV DNA decreased in an HBV mouse model with an agonistic antibody that activates OX40. This viral inhibition process coincides with changes in liver inflammation, the ratio of T cell subsets, and T cell-related cytokines. Finally, we found that the OX40 activation-mediated inhibition of HBV replication was more dependent on CD8+ T cells than on CD4+ T cells.

The expression levels of the immune checkpoints OX40/OX40L in adult patients with CHB are closely related to virus clearance. The activation of OX40 can suppress HBV replication through a mechanism that is more dependent on CD8+ T cells than on CD4+ T cells. Thus, OX40 is a promising therapeutic target for the treatment of CHB.

Chronic hepatitis B (CHB) arises from a persistent hepatitis B virus (HBV) infection, complicating efforts for a functional cure. Kupffer cells (KCs), liver-resident macrophages, are pivotal in mediating immune tolerance to HBV. Although CD163 marks M2-polarized KCs, its precise role in HBV infection remains unclear and warrants further investigation.

CD163 expression in liver tissues of patients with CHB was analyzed using the Gene Expression Omnibus (GEO) database. Cd163 knockout mice were utilized to establish HBV-persistent mouse model, and CD163 deficiency effect on HBV viral markers and T cell immune responses were examined in vivo and in vitro.

CD163 expression was elevated and correlated with ALT levels in the liver of patients with CHB. In HBV-persistent mouse model, CD163 deficiency facilitated the clearance of HBsAg, HBeAg, HBV DNA, and HBcAg. Additionally, CD163 deficiency promoted the differentiation of naïve T cells into HBV-specific effector T cells. Further, we found that CD163 deficiency reduces KCs-derived IL-10 secretion, and blocking IL-10 further strengthens the enhanced HBV-specific T cell response due to CD163 deficiency.

Our findings indicate that CD163 deficiency enhances the HBV-specific T cell response, thereby facilitating HBV clearance through reducing KCs-derived IL-10 secretion. This suggests that CD163 may serve as a potential target for the restoration of exhausted T cell function.

Nucleo(s)tide analogue (NUC) cessation can lead to hepatitis B surface antigen (HBsAg) clearance but also a high rate of virological relapse. However, the effect of pegylated interferon alpha-2a (PegIFN-α-2a) on virological relapse after NUC cessation is unknown. Therefore, this study aimed to evaluate the effect of switching from NUC to PegIFN-α-2a treatment for 48 weeks on virological relapse up to week 96.

In this multicenter randomized-controlled clinical trial, 180 non-cirrhotic patients with HBeAg-negative chronic hepatitis B on continuous NUC therapy for ≥2.5 years, with HBV DNA levels <60 IU/ml, were randomized to discontinue NUC therapy (n = 90) or receive 48 weeks of PegIFN-α-2a treatment (n = 90). Patients were followed up for up to 96 weeks. The primary endpoint was the virological relapse rate up to week 96.

Intention-to-treat analysis revealed patients in the interferon monotherapy group had significantly lower cumulative virological relapse rates than the NUC cessation group until week 96 (20.8% vs. 53.6%, p <0.0001). Consistently, a significantly lower proportion of patients in the interferon monotherapy group had virological relapse than those in the NUC cessation group at 48 weeks off treatment (17.8% vs. 36.7%, p = 0.007). The virological relapse rate positively correlated with HBsAg levels in the NUC cessation group. The interferon monotherapy group had a lower cumulative clinical relapse rate (7.8% vs. 20.9%, p = 0.008) and a higher HBsAg loss rate (21.5% vs. 9.0%, p = 0.03) than the NUC cessation group.

Switching from NUC to PegIFN-α-2a treatment for 48 weeks significantly reduces virological relapse rates and leads to higher HBsAg loss rates than NUC treatment cessation alone in patients with HBeAg-negative chronic hepatitis B.

Nucleo(s)tide analogue (NUC) cessation can lead to HBsAg clearance but also a high rate of virological relapse, but an optimized scheme to reduce the virological relapse rate after NUC withdrawal is yet to be reported. This randomized-controlled trial investigated the effect of switching from NUC to PegIFN-α-2a treatment for 48 weeks on virological relapse up to week 96 in patients with HBeAg-negative chronic hepatitis B. The interferon monotherapy group had a significantly lower cumulative virological relapse rate (20.8% vs. 53.6%, p <0.0001) and higher HBsAg loss rate (21.5% vs. 9.0%, p = 0.03) than the NUC cessation group up to week 96. This provides an optimized strategy for NUC cessation in HBeAg-negative patients.

NCT02594293.

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.

Hyperprogressive disease can occur in cancer patients receiving immune checkpoint blockade (ICB) therapy, but whether and how reactive cytotoxic T lymphocytes (CTLs) exert protumorigenic effects in this context remain elusive. Herein, our study reveals that pericancerous macrophages cross-present antigens to CD103+ CTLs in hepatocellular carcinoma (HCC) via the endoplasmic reticulum (ER)-associated degradation machinery-mediated cytosolic pathway. This process leads to the retention of CD103+ CTLs in the pericancerous area, whereby they activate NLRP3 inflammasome in macrophages, promoting hepatoma progression and resistance to immunotherapy. Our single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics analysis of HCC patients shows that despite their tissue-resident effector phenotype, the aggregation of CD103+ CTLs predicts unfavorable clinical outcomes for HCC patients receiving multiple types of treatment. Correspondingly, therapeutic strategies that redistribute CD103+ CTLs can disrupt this pathogenic interplay with macrophages, enhancing the efficacy of ICB treatment against HCC.

Hepatitis B virus (HBV) is an ancient virus that has evolved unique strategies to persist as a chronic infection in humans. Here, I summarize the innate and adaptive features of the HBV-host interaction, and I discuss how different profiles of antiviral immunity cannot be predicted only on the basis of virological and clinical parameters.

In patients who progress from acute hepatitis B virus (HBV) infection to a chronic HBV (CHB) infection, CD8+ T cells fail to eliminate the virus and become impaired. A functional cure of CHB likely requires CD8+ T cell responses different from those induced by the infection. Here we report preclinical immunogenicity and efficacy of an HBV therapeutic vaccine that includes herpes simplex virus (HSV) glycoprotein D (gD), a checkpoint modifier of early T cell activation, that augments CD8+ T cell responses. The vaccine is based on a chimpanzee adenovirus serotype 6 (AdC6) vector, called AdC6-gDHBV2, which targets conserved and highly immunogenic regions of the viral polymerase and core antigens fused to HSV gD. The vaccine was tested with and without gD in mice for immunogenicity, and in an AAV8-1.3HBV vector model of antiviral efficacy. The vaccine encoding the HBV antigens within gD stimulates potent and broad CD8+ T cell responses. In a surrogate model of HBV infection, a single intramuscular injection achieved pronounced and sustained declines of circulating HBV DNA copies and HBV surface antigen; both inversely correlated with HBV-specific CD8+ T cell frequencies in spleen and liver.

Over 300 million individuals worldwide are chronically infected with hepatitis B virus and at risk for progressive liver disease. Due to the lack of a therapy that reliably achieves viral elimination and the variability of liver disease progression, treatment decisions are guided by the degree of liver disease and viral biomarkers as the viral life-cycle is well characterized and largely conserved between individuals. In contrast, the immunological landscape is much more heterogeneous and diverse and the measurement of its components is less well standardized. Due to the lack of a universal and easily measurable set of biomarkers, clinical practice guidelines remain controversial, aiming for a balance between simplifying treatment decisions by reducing biomarker requirements and using all available biomarkers to avoid overtreatment of patients with low risk for disease progression. While approved therapies such as nucleos(t)ide analogs improve patient outcomes, the inability to achieve a complete cure highlights the need for novel therapies. Since no treatment candidate has demonstrated universal efficacy, biomarkers will remain important for treatment stratification. Here, we summarize the current knowledge on virological and immunological biomarkers with a specific focus on how they might be beneficial in guiding treatment decisions in chronic hepatitis B.

Hepatitis B virus (HBV) clearance depends on an effective adaptive immune response, especially HBV-specific T cell-mediated cellular immunity; however, it is difficult to produce enough HBV-specific T cells effectively.

In this work, we investigated the proportions of stimulated cells, serum, and culture media as the three primary factors to determine the most effective procedure and applied it to HLA-A2 (+) people. In parallel, we also examined the correlation between clinical parameters and HBV-specific immunity. Concerning amplification efficiency, 4 × 105 cells stimulation was superior to 2 × 106 cells stimulation, AIM-V medium outperformed 1640 medium, and fetal bovine serum (FBS) exceeded human AB serum under comparable conditions. As expected, this procedure is also suitable for developing HBV-specific CD8 + T cells in HLA-A2(+) individuals. Expanded HBV-specific T cell responses decreased with treatment time and were negatively correlated with HBV DNA and HBsAg. Furthermore, the number of HBV-specific IFN-γ + SFCs was strongly correlated with the ALT level and negatively correlated with the absolute lymphocyte count and the ALB concentration.

We confirm that stimulating 4 × 105 PBMCs in AIM-V medium supplemented with 10% FBS is the best approach and that HBeAg, HBsAg, and ALB are independent predictors of HBV-specific T-cell responses.

Hepatitis B virus (HBV)-specific T cell response is a major host immune response to control the virus. However, it is still unclear how it affects long-term outcomes of chronic hepatitis B patients, especially those who stop nucleos(t)ide analogue (NA) therapy. We aimed to explore whether the HBV-specific T cell response at the end of treatment (EOT) was associated with clinical outcomes.

In a prospective cohort study, 51 HBeAg-negative patients who discontinued NA therapy were enrolled.

In a mean follow-up of 25.3 months, 25 patients developed clinical relapse. We found that a stronger hepatitis B core (HBc)-specific T cell response at EOT was associated with a lower risk of clinical relapse. Compared to the low-response group, the high-response group had a lower risk of clinical relapse with hazard ratio of 0.21 (95% CI: 0.05-0.88). The high HBc-specific T cell response was associated with reduced surge of HBV DNA and HBcrAg during the first year of follow-up. The T cell response at EOT was comparable between different NA treatments. Notably, the overall HBV-specific T cell response could be partially restored along with clinical relapse; however, such reinvigorated T cell response was not associated with HBsAg seroclearance.

A higher HBc-specific T cell response at EOT was associated with lower risk of clinical relapse and reduced surge of HBV DNA and HBcrAg levels off NA therapy.

Hepatitis B core antibody (anti-HBc) is commonly present in patients with chronic hepatitis B virus (HBV) infection and serves as a marker of humoral immunity. Herein, we aim to investigate the correlation between anti-HBc and antiviral immune response and its putative role in HBV control.

Quantitative anti-HBc and levels of anti-HBc subtypes were measured in chronic hepatitis B (CHB) patients. The effects of anti-HBc on immune cells and HBV replication were evaluated using the HBV mouse models and human hepatoma cell lines.

Baseline levels of IgG1 and IgG3 anti-HBc were elevated in CHB patients with favorable treatment response, and correlated with the virological response observed at week 52. Additionally, increased levels of IgM and IgG1 anti-HBc were observed exclusively in CHB patients with liver inflammation. Notably, significant correlations were identified between quantitative levels of anti-HBc and the frequencies of HBcAg-specific CD8+ T cells. Intriguingly, HBcAg efficiently activates T cells aided by B cells in vitro experiments. Moreover, anti-HBc inhibits HBV replication either by a direct effect or through complement-mediated cytotoxicity in HBV-producing cell lines.

Anti-HBc reflects the activation of an HBV-specific CD8+ T cell immune response and may have anti-HBV activity.

Viral hepatitis is a major cause of liver illness worldwide. Despite advances in the understanding of these infections, the pathogenesis of hepatitis remains a complex process driven by intricate interactions between hepatitis viruses and host cells at the molecular level. This paper will examine in detail the dynamics of these host-pathogen interactions, highlighting the key mechanisms that regulate virus entry into the hepatocyte, their replication, evasion of immune responses, and induction of hepatocellular damage. The unique strategies employed by different hepatitis viruses, such as hepatitis B, C, D, and E viruses, to exploit metabolic and cell signaling pathways to their advantage will be discussed. At the same time, the innate and adaptive immune responses put in place by the host to counter viral infection will be analyzed. Special attention will be paid to genetic, epigenetic, and environmental factors that modulate individual susceptibility to different forms of viral hepatitis. In addition, this work will highlight the latest findings on the mechanisms of viral persistence leading to the chronic hepatitis state and the potential implications for the development of new therapeutic strategies. Fully understanding the complex host-pathogen interactions in viral hepatitis is crucial to identifying new therapeutic targets, developing more effective approaches for treatment, and shedding light on the mechanisms underlying progression to more advanced stages of liver damage.

Hepatitis B virus (HBV)-specific CD8+ T cells play a dominant role during acute-resolving HBV infection but are functionally impaired during chronic HBV infection in humans. These functional deficits have been linked with metabolic and phenotypic heterogeneity, but it has remained unclear to what extent different subsets of HBV-specific CD8+ T cells still suppress viral replication. We addressed this issue by deep profiling, functional testing and perturbation of HBV-specific CD8+ T cells during different phases of chronic HBV infection. Our data revealed a mechanism of effector CD8+ T cell attenuation that emerges alongside classical CD8+ T cell exhaustion. Attenuated HBV-specific CD8+ T cells were characterized by cytotoxic properties and a dampened effector differentiation program, determined by antigen recognition and TGFβ signaling, and were associated with viral control during chronic HBV infection. These observations identify a distinct subset of CD8+ T cells linked with immune efficacy in the context of a chronic human viral infection with immunotherapeutic potential.

The early and mid-career researchers (EMCRs) of scientific communities represent the forefront of research and the future direction in which a field takes. The opinions of this key demographic are not commonly aggregated to audit fields and precisely demonstrate where challenges lie for the future. To address this, we initiated the inaugural International Emerging Researchers Workshop for the global Hepatitis B and Hepatitis D scientific community (75 individuals). The cohort was split into small discussion groups and the significant problems, challenges, and future directions were assessed. Here, we summarise the outcome of these discussions and outline the future directions suggested by the EMCR community. We show an effective approach to gauging and accumulating the ideas of EMCRs and provide a succinct summary of the significant gaps remaining in the Hepatitis B and Hepatitis D field.

Hepatitis B surface antigen (HBsAg) loss or functional cure (FC) is considered the optimal therapeutic outcome for patients with chronic hepatitis B (CHB). However, the immune-pathological biomarkers and underlying mechanisms of FC remain unclear. In this study we comprehensively interrogate disease-associated cell states identified within intrahepatic tissue and matched PBMCs (peripheral blood mononuclear cells) from patients with CHB or after FC, at the resolution of single cells, to provide novel insights into putative mechanisms underlying FC.

We combined single-cell transcriptomics (single-cell RNA sequencing) with multiparametric flow cytometry-based immune phenotyping, and multiplexed immunofluorescence to elucidate the immunopathological cell states associated with CHB vs. FC.

We found that the intrahepatic environment in CHB and FC displays specific cell identities and molecular signatures that are distinct from those found in matched PBMCs. FC is associated with the emergence of an altered adaptive immune response marked by CD4 cytotoxic T lymphocytes, and an activated innate response represented by liver-resident natural killer cells, specific Kupffer cell subtypes and marginated neutrophils. Surprisingly, we found MHC class II-expressing hepatocytes in patients achieving FC, as well as low but persistent levels of covalently closed circular DNA and pregenomic RNA, which may play an important role in FC.

Our study provides conceptually novel insights into the immuno-pathological control of HBV cure, and opens exciting new avenues for clinical management, biomarker discovery and therapeutic development. We believe that the discoveries from this study, as it relates to the activation of an innate and altered immune response that may facilitate sustained, low-grade inflammation, may have broader implications in the resolution of chronic viral hepatitis.

This study dissects the immuno-pathological cell states associated with functionally cured chronic hepatitis B (defined by the loss of HBV surface antigen or HBsAg). We identified the sustained presence of very low viral load, accessory antigen-presenting hepatocytes, adaptive-memory-like natural killer cells, and the emergence of helper CD4 T cells with cytotoxic or effector-like signatures associated with functional cure, suggesting previously unsuspected alterations in the adaptive immune response, as well as a key role for the innate immune response in achieving or maintaining functional cure. Overall, the insights generated from this study may provide new avenues for the development of alternative therapies as well as patient surveillance for better clinical management of chronic hepatitis B.

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.

CD8 T cells provide immunity to virus infection through recognition of epitopes presented by peptide major histocompatibility complexes (pMHCs). To establish a concise panel of widely recognized T cell epitopes from common viruses, we combined analysis of TCR down-regulation upon stimulation with epitope-specific enumeration based on barcode-labeled pMHC multimers. We assess CD8 T cell binding and reactivity for 929 previously reported epitopes in the context of 1 of 25 HLA alleles representing 29 viruses. The prevalence and magnitude of CD8 T cell responses were evaluated in 48 donors and reported along with 137 frequently recognized virus epitopes, many of which were underrepresented in the public domain. Eighty-four percent of epitope-specific CD8 T cell populations demonstrated reactivity to peptide stimulation, which was associated with effector and long-term memory phenotypes. Conversely, nonreactive T cell populations were associated primarily with naive phenotypes. Our analysis provides a reference map of epitopes for characterizing CD8 T cell responses toward common human virus infections.

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.

The natural progression of chronic hepatitis B virus (HBV) infection is dynamic, but the longitudinal landscape of HBV serological markers with host antiviral immune response relevant hepatic inflammatory damage remains undetermined. To this issue, we studied the association of HBV serological markers with the severity of hepatic inflammatory damage and enumerated HBV-specific T cells using the cultured enzyme-linked immune absorbent spot (ELISpot). Five hundred and twenty-four treatment-naïve chronic HBV infection patients were enrolled. The Spearman correlation analysis revealed that in hepatitis B e antigen (HBeAg)-positive patients, all HBV virologic indicators negatively correlated with liver inflammatory damage and fibrosis (p < 0.01). Stronger correlations were accessed in the subgroup of HBeAg-positive patients with HBV DNA > 2 × 106 IU/mL (p < 0.01), whereas negative correlations disappeared in patients with HBV DNA ≤ 2 × 106 IU/mL. Surprisingly, in HBeAg-negative patients, the HBV DNA level was positively correlated with the hepatic inflammatory damage (p < 0.01). The relationship between type Ⅱ interferon genes expression and HBV DNA levels also revealed a direct shift from the initial negative to positive in HBeAg-positive patients with HBV DNA declined below 2 × 106 IU/mL. The number of HBV-specific T cells were identified by interferon γ ELISpot assays and showed a significant increase from HBeAg-positive to HBeAg-negative group. The host's anti-HBV immunity remains effective in HBeAg-positive patients with HBV DNA levels exceeding 2 × 106 IU/mL, as it efficiently eliminates infected hepatocytes and inhibits HBV replication. However, albeit the increasing number of HBV-specific T cells, the host antiviral immune response shifts towards dysfunctional when the HBV DNA load drops below this threshold, which causes more pathological damage and disease progression.

CD8+ T cells affect the outcomes of pancreatic ductal adenocarcinoma (PDAC). Using tissue samples at pre-treatment to monitor the immune response is challenging, while blood samples are beneficial in overcoming this limitation. In this study, we measured peripheral antigen-specific CD8+ T cell responses against four different tumor-associated antigens (TAAs) in PDAC using flow cytometry and investigated their relationships with clinical features. We analyzed the optimal timing within the treatment course for effective immune checkpoint inhibition in vitro. We demonstrated that the frequency of TAA-specific IFNγ+4-1BB+ CD8+ T cells was correlated with a fold reduction in CA19-9 before and after neoadjuvant therapy. Moreover, patients with TAA-specific IFNγ+4-1BB+ CD8+ T cells after surgery exhibited a significantly improved disease-free survival. Anti-PD-1 treatment in vitro increased the frequency of TAA-specific IFNγ+4-1BB+ CD8+ T cells before neoadjuvant therapy in patients, suggesting the importance of the timing of anti-PD-1 inhibition during the treatment regimen. Our results indicate that peripheral immunophenotyping, combined with highly sensitive identification of TAA-specific responses in vitro as well as detailed CD8+ T cell subset profiling via ex vivo analysis, may serve as peripheral biomarkers to predict treatment outcomes and therapeutic efficacy of immunotherapy plus neoadjuvant chemotherapy.

The clinical routine test of HBV-specific T cell reactivity is still limited due to the high polymorphisms of human leukocyte antigens (HLA) in patient cohort and the lack of universal detection kit, thus the clinical implication remains disputed.

A broad-spectrum peptide library, which consists of 103 functionally validated CD8+ T-cell epitopes spanning overall HBsAg, HBeAg, HBx and HBpol proteins and fits to the HLA polymorphisms of Chinese and Northeast Asian populations, was grouped into eight peptide pools and was used to establish an ELISpot assay for enumerating the reactive HBV-specific T cells in PBMCs. Totally 294 HBV-infected patients including 203 ones with chronic hepatitis B (CHB), 13 ones in acute resolved stage (R), 52 ones with liver cirrhosis (LC) and 26 ones with hepatocellular carcinoma (HCC) were detected, and 33 CHB patients were longitudinally monitored for 3 times with an interval of 3-5 months.

The numbers of reactive HBV-specific T cells were significantly correlated with ALT level, HBsAg level, and disease stage (R, CHB, LC and HCC), and R patients displayed the strongest HBV-specific T cell reactivity while CHB patients showed the weakest one. For 203 CHB patients, the numbers of reactive HBV-specific T cells presented a significantly declined trend when the serum viral DNA load, HBsAg, HBeAg or ALT level gradually increased, but only a very low negative correlation coefficient was defined (r = - 0.21, - 0.21, - 0.27, - 0.079, respectively). Different Nucleotide Analogs (NUCs) did not bring difference on HBV-specific T cell reactivity in the same duration of treatment. NUCs/pegIFN-α combination led to much more reactive HBV-specific T cells than NUCs monotherapy. The dynamic numbers of reactive HBV-specific T cells were obviously increasing in most CHB patients undergoing routine treatment, and the longitudinal trend possess a high predictive power for the hepatitis progression 6 or 12 months later.

The presented method could be developed into an efficient reference method for the clinical evaluation of cellular immunity. The CHB patients presenting low reactivity of HBV-specific T cells have a worse prognosis for hepatitis progression and should be treated using pegIFN-α to improve host T-cell immunity.

Hepatitis B virus (HBV) infection significantly impacts Asian populations. The influences of continuous HBV antigen and inflammatory stimulation to T cells in chronic hepatitis B (CHB) remain unclear. In this study, we first conducted bioinformatics analysis to assess T-cell signaling pathways in CHB patients. In a Taiwanese cohort, we examined the phenotypic features of HBVcore -specific T cells and their correlation with clinical parameters. We used core protein overlapping peptides from the Taiwan prevalent genotype B HBV to investigate the antiviral response and the functional implication of HBV-specific T cells. In line with Taiwanese dominant HLA-alleles, we also evaluated ex vivo HBVcore -specific T cells by pMHC-tetramers targeting epitopes within HBV core protein. Compared to healthy subjects, we disclosed CD8 T cells from CHB patients had higher activation marker CD38 levels but showed an upregulation in the inhibitory receptor PD-1. Our parallel study showed HBV-specific CD8 T cells were more activated with greater PD-1 expression than CMV-specific subset and bulk CD8 T cells. Moreover, our longitudinal study demonstrated a correlation between the PD-1 fluctuation pattern of HBVcore -specific CD8 T cells and liver inflammation in CHB patients. Our research reveals the HBV core antigen-mediated immunopathologic profile of CD8 T cells in chronic HBV infection. Our findings suggest the PD-1 levels of HBVcore -specific CD8 T cells can be used as a valuable indicator of personal immune response for clinical application in hepatitis management.

Long-term nucleos(t)ide analog (Nuc) treatment can reduce HCC in patients with HBV-related liver cirrhosis (HBV-LC). Earlier small cohort studies showed a comparable 5-year incidence of HCC in HBeAg-negative patients with HBV-LC who stopped and those continued Nuc therapy. This study aimed to validate these findings using a large cohort with 10-year follow-up.

From 2 centers, 494 HBeAg-negative patients with HBV-LC who stopped (finite group) and 593 who continued (continuous group) Nuc therapy were recruited. HCC, HBsAg loss, liver-related mortality/transplantation, and overall survival rates were compared between 2 groups with 1:1 propensity score matching of sex, treatment history, types of Nuc, age, transaminases, platelet count, and HBsAg levels at end of therapy in finite group or 3-year on-therapy in continuous groups. During a median follow-up of 6.2 (3.4-8.9) years, the annual and 10-year HCC incidence were lower in finite group (1.6 vs. 3.3%/y and 10-y 15.7% vs. 26.8%, respectively; log-rank test, p <0.0001). The finite group showed greater HBsAg decline/year (-0.116 vs. -0.095 log 10 IU/mL, p =0.0026) and 7.6 times higher 10-year incidence of HBsAg loss (22.7% vs. 3%, p <0.0001). Multivariate Cox regression showed finite therapy an independent factor for HBsAg loss (adjusted HR: 11.79) but protective against HCC (adjusted HR: 0.593), liver-related mortality/transplantation (adjusted HR: 0.312), and overall mortality (adjusted HR: 0.382).

Finite Nuc therapy in HBeAg-negative HBV-LC may reduce HCC incidence, increase HBsAg loss, and improve survival. Greater HBsAg decline/loss may reflect enhanced immunity and contribute to the reduction of hepatic carcinogenesis.

Current guidelines suggest that nucleos(t)ide analogues (NA) can be discontinued before HBsAg loss in a selected group of chronic hepatitis B (CHB) patients. We aimed to study the safety and off-treatment response after NA cessation.

This is a prospective, multicentre, cohort study in which eligible patients discontinued NA therapy. Adult patients, with a CHB mono-infection, HBeAg-negative, without a (history of) liver cirrhosis, who had achieved long-term viral suppression were eligible. Follow-up visits were planned at week 2-4-8-12-24-36-48-72-96. Re-treatment criteria included severe hepatitis (ALT >10x ULN), signs of imminent liver failure (bilirubin >1.5x ULN or INR >1.5), or at the physician's own discretion.

In total, 33 patients were enrolled. Patients were predominantly Caucasian (45.5%) and had genotype A/B/C/D/unknown in 3/4/6/10/10 (9.1/12.1/18.2/30.3/30.3%). At week 48, 15 patients (45.5%) achieved a sustained response (HBV DNA <2,000 IU/mL). At week 96, 13 patients (39.4%) achieved a sustained response, 4 (12.1%) achieved HBsAg loss, and 12 (36.4%) were re-treated. Severe hepatitis was the main reason for re-treatment (n=7, 21.2%). One patient with severe hepatitis developed jaundice, without signs of hepatic decompensation. Re-treatment was successful in all patients.

NA therapy can be ceased in a highly selected group of CHB patients if close follow-up can be guaranteed. Treatment cessation may increase the chance of HBsAg loss in selected patients, which is counterbalanced by a significant risk of severe hepatitis.

Finite nucleos(t)ide analog (NA) therapy has been proposed as an alternative treatment strategy for chronic hepatitis B (CHB), but biomarkers for post-treatment monitoring are limited. We investigated whether measuring hepatitis B core-related antigen (HBcrAg) after NA cessation may stratify the risk of subsequent clinical relapse (CR).

This retrospective multicenter analysis enrolled adults with CHB who were prospectively monitored after discontinuing entecavir or tenofovir with negative HBeAg and undetectable HBV DNA at the end of treatment (EOT). Patients with cirrhosis or malignancy were excluded. CR was defined as serum alanine aminotransferase > two times the upper limit of normal with recurrent viremia. We applied time-dependent Cox proportional hazard models to clarify the association between HBcrAg levels and subsequent CR.

The cohort included 203 patients (median age, 49.8 years; 76.8% male; 60.6% entecavir) who had been treated for a median of 36.9 months (interquartile range [IQR], 36.5-40.1). During a median post-treatment follow-up of 31.7 months (IQR, 16.7-67.1), CR occurred in 104 patients with a 5-year cumulative incidence of 54.8% (95% confidence interval [CI], 47.1-62.4%). Time-varying HBcrAg level was a significant risk factor for subsequent CR (adjusted hazard ratio [aHR], 1.53 per log U/mL; 95% CI, 1.12-2.08) with adjustment for EOT HBsAg, EOT anti-HBe, EOT HBcrAg and time-varying HBsAg. During follow-up, HBcrAg <1,000 U/mL predicted a lower risk of CR (aHR, 0.41; 95% CI, 0.21-0.81).

Dynamic measurement of HBcrAg after NA cessation is predictive of subsequent CR and may be useful to guide post-treatment monitoring.

There are no immunological biomarkers that predict control of chronic hepatitis B (CHB). The lack of immune biomarkers raises concerns for therapies targeting PD-1/PD-L1 because they have the potential for immune-related adverse events. Defining specific immune functions associated with control of HBV replication could identify patients likely to respond to anti-PD-1/PD-L1 therapies and achieve a durable functional cure.

We enrolled immunotolerant, HBeAg+ immune-active (IA+), HBeAg- immune-active (IA-), inactive carriers, and functionally cured patients to test ex vivo PD-1 blockade on HBV-specific T cell functionality. Peripheral blood mononuclear cells were stimulated with overlapping peptides covering HBV proteins +/-α-PD-1 blockade. Functional T cells were measured using a 2-color FluoroSpot assay for interferon-γ and IL-2. Ex vivo functional restoration was compared to the interferon response capacity assay, which predicts overall survival in cancer patients receiving checkpoint inhibitors.

Ex vivo interferon-γ+ responses did not differ across clinical phases. IL-2+ responses were significantly higher in patients with better viral control and preferentially restored with PD-1 blockade. Inactive carrier patients displayed the greatest increase in IL-2 production, which was dominated by CD4 T cell and response to the HBcAg. The interferon response capacity assay significantly correlated with the degree of HBV-specific T cell restoration.

IL-2 production was associated with better HBV control and superior to interferon-γ as a marker of T cell restoration following ex vivo PD-1 blockade. Our study suggests that responsiveness to ex vivo PD-1 blockade, or the interferon response capacity assay, may support stratification for α-PD-1 therapies.

Chronic hepatitis B virus (HBV) infection remains a major public health concern globally, and T cell responses are widely believed to play a pivotal role in mediating HBV clearance. Accordingly, research on the characteristics of HBV-specific T cell responses, from activation to exhaustion, has advanced rapidly. Here, we summarize recent developments in characterizing T cell immunity in HBV infection by reviewing basic and clinical research published in the last five years. We provide a comprehensive summary of the mechanisms that induce effective anti-HBV T cell immunity, as well as the latest developments in understanding T cell dysfunction in chronic HBV infection. Furthermore, we briefly discuss current novel treatment strategies aimed at restoring anti-HBV T cell responses.

Liver failure, which is predominantly caused by hepatitis B (HBV) can be improved by an artificial liver support system (ALSS). This study investigated the phenotypic heterogeneity of immunocytes in patients with HBV-related acute-on-chronic liver failure (HBV-ACLF) before and after ALSS therapy.

A total of 22 patients with HBV-ACLF who received ALSS therapy were included in the study. Patients with Grade I according to the ACLF Research Consortium score were considered to have improved. Demographic and laboratory data were collected and analyzed during hospitalization. Immunological features of peripheral blood in the patients before and after ALSS were detected by mass cytometry analyses.

In total, 12 patients improved and 10 patients did not. According to the immunological features data after ALSS, the proportion of circulating monocytes was significantly higher in non-improved patients, but there were fewer γδT cells compared with those in improved patients. Characterization of 37 cell clusters revealed that the frequency of effector CD8+ T (P = 0.003), CD4+ TCM (P = 0.033), CD4+ TEM (P = 0.039), and inhibitory natural killer (NK) cells (P = 0.029) decreased in HBV-ACLF patients after ALSS therapy. Sub group analyses after treatment showed that the improved patients had higher proportions of CD4+ TCM (P = 0.010), CD4+ TEM (P = 0.021), and γδT cells (P = 0.003) and a lower proportion of monocytes (P = 0.012) compared with the non-improved patients.

Changes in effector CD8+ T cells, effector and memory CD4+ T cells, and inhibitory NK cells are associated with ALSS treatment of HBV-ACLF. Moreover, monocytes and γδT cells exhibited the main differences when patients obtained different prognoses. The phenotypic heterogeneity of lymphocytes and monocytes may contribute to the prognosis of ALSS and future immunotherapy strategies.