Impact of Hepatitis B Surface and Core Antibody Levels on Hepatitis B Virus Reactivation.

Hepatitis B virus reactivation (HBV-R) is a serious complication that can occur in patients with resolved HBV infection during cancer chemotherapy. We examined the levels of HBV surface antibody (HBsAb) and HBV core antibody (HBcAb) to assess the incidence of HBV-R in cancer patients including hematopoietic stem cell transplantation (HSCT) and rituximab administration. This retrospective cohort study included 590 patients with resolved HBV infection. The incidence of HBV-R was evaluated 761.5 (range, 90-3898) days after the inititiation of chemotherapy. Of the patients, 13 (2.2%) developed HBV-R after the start of chemotherapy. All 13 patients exhibited lower HBsAb (<100 mIU/mL) levels at baseline. A higher level of HBcAb (≥100 cut off index (C.O.I.)) was a possible risk factor for HBV-R as well as HSCT and rituximab administration. The simultaneous presence of HBsAb <100 mIU/mL and HBcAb ≥100 C.O.I. increased the risk of HBV-R by 18.5%. Patients treated with rituximab were at a higher risk of HBV-R (18.4%) despite having HBcAb <100 C.O.I. Our results suggest that assessment of HBsAb and HBcAb levels prior to the chemotherapy is important for identifying patients at high risk of HBV-R, especially in solid cancers without HSCT and rituximab administration.

Immune-Escape Mutations Are Prevalent among Patients with a Coexistence of HBsAg and Anti-HBs in a Tertiary Liver Center in the United States.

The concurrent seropositivity of HBsAg and anti-HBs has been described among patients with chronic hepatitis B (CHB), but its prevalence is variable. HBV S-gene mutations can affect the antigenicity of HBsAg. Patients with mutations in the 'α' determinant region of the S gene can develop severe HBV reactivation under immunosuppression. In this study at a tertiary liver center in the United States, we evaluated the frequency and virological characteristics of the HBsAg mutations among CHB patients with the presence of both HBsAg and anti-HBs. In this cohort, 45 (2.1%) of 2178 patients were identified to have a coexistence of HBsAg and anti-HBs, and 24 had available sera for the genome analysis of the Pre-S1, Pre-S2, and S regions. The frequency of mutations in the S gene was significantly higher among those older than 50 years (mean 8.5 vs. 5.4 mutations per subject, p = 0.03). Twelve patients (50%) had mutations in the 'α' determinant region of the S gene. Mutations at amino acid position 126 were most common in eight subjects. Three had a mutation at position 133. Only one patient had a mutation at position 145-the classic vaccine-escape mutation. Despite the universal HBV vaccination program, the vaccine-escape mutant is rare in our cohort of predominantly Asian patients.

CARs derived from broadly neutralizing, human monoclonal antibodies identified by single B cell sorting target hepatitis B virus-positive cells.

To design new CARs targeting hepatitis B virus (HBV), we isolated human monoclonal antibodies recognizing the HBV envelope proteins from single B cells of a patient with a resolved infection. HBV-specific memory B cells were isolated by incubating peripheral blood mononuclear cells with biotinylated hepatitis B surface antigen (HBsAg), followed by single-cell flow cytometry-based sorting of live, CD19+ IgG+ HBsAg+ cells. Amplification and sequencing of immunoglobulin genes from single memory B cells identified variable heavy and light chain sequences. Corresponding immunoglobulin chains were cloned into IgG1 expression vectors and expressed in mammalian cells. Two antibodies named 4D06 and 4D08 were found to be highly specific for HBsAg, recognized a conformational and a linear epitope, respectively, and showed broad reactivity and neutralization capacity against all major HBV genotypes. 4D06 and 4D08 variable chain fragments were cloned into a 2nd generation CAR format with CD28 and CD3zeta intracellular signaling domains. The new CAR constructs displayed a high functional avidity when expressed on primary human T cells. CAR-grafted T cells proved to be polyfunctional regarding cytokine secretion and killed HBV-positive target cells. Interestingly, background activation of the 4D08-CAR recognizing a linear instead of a conformational epitope was consistently low. In a preclinical model of chronic HBV infection, murine T cells grafted with the 4D06 and the 4D08 CAR showed on target activity indicated by a transient increase in serum transaminases, and a lower number of HBV-positive hepatocytes in the mice treated. This study demonstrates an efficient and fast approach to identifying pathogen-specific monoclonal human antibodies from small donor cell numbers for the subsequent generation of new CARs.

Comparison of the effectiveness four years after Homo/Hetero prime-boost with 10 µg HP and 20 µg CHO recombinant hepatitis B vaccine at 1 and 6 months in maternal HBsAg-negative children.

Introduction: Limited data were available on the effectivenessfour years after Homo or Hetero prime-boost with 10 µg Hansenulapolymorpha recombinant hepatitis B vaccine (HepB-HP) and 20 µgChinese hamster ovary cell HepB (HepB-CHO). Methods: A crosssectional study was performed in maternalhepatitis B surface antigen (HBsAg)-negative children whoreceived one dose of 10 µg HepB-HP at birth, Homo or Heteroprime-boost with 10 µg HepB-HP and 20 µg HepB-CHO at 1 and 6months. HBsAg and hepatitis B surface antibody (anti-HBs) fouryears after immunization were quantitatively detected by achemiluminescent microparticle immunoassay (CMIA). Results: A total of 359 children were included; 119 childrenreceived two doses of 10 µg HepB-HP and 120 children receivedtwo doses of 20 µg HepB-CHO, called Homo prime-boost; 120children received Hetero prime-boost with 10 µg HepB-HP and 20µg HepB-CHO. All children were HBsAg negative. The geometricmean concentration (GMC) and overall seropositivity rate (SPR) ofanti-HBs were 59.47 (95%CI: 49.00 - 72.16) mIU/ml and 85.51%(307/359). Nearly 15% of the study subjects had an anti-HBsconcentration < 10 mIU/ml and 5.01% had an anti-HBsconcentration ≤ 2.5 mIU/ml. The GMC of the 20 µg CHO Homoprime-boost group [76.05 (95%CI: 54.97 - 105.19) mIU/ml] washigher than that of the 10 µg HP Homo group [45.86 (95%CI:31.94 - 65.84) mIU/ml] (p = 0.035). The GMCs of the Heteroprime-boost groups (10 µg HP-20 µg CHO and 20 µg CHO-10 µgHP) were 75.86 (95% CI: 48.98 - 107.15) mIU/ml and 43.65(95%CI: 27.54 - 69.18) mIU/ml, respectively (p = 0.041). Aftercontrolling for sex influence, the SPR of the 20 µg CHO Homoprime-boost group was 2.087 times than that of the 10 µg HPHomo group. Discussion: The HepB booster was not necessary in the generalchildren, Homo/Hetero prime-boost with 20 µg HepB-CHO wouldincrease the anti-HBs concentration four years after immunization,timely testing and improved knowledge about the self-pay vaccinewould be good for controlling hepatitis B.

Interferon-γ+ Th1 activates intrahepatic resident memory T cells to promote HBsAg loss by inducing M1 macrophage polarization.

The immune mechanism underlying hepatitis B surface antigen (HBsAg) loss, particularly type I inflammatory response, during pegylated interferon-α (PEG-IFN) therapy remains unclear. In this study, we aimed to elucidate such immune mechanisms. Overall, 82 patients with chronic hepatitis B (CHB), including 41 with HBsAg loss (cured group) and 41 uncured patients, received nucleos(t)ide analogue and PEG-IFN treatments. Blood samples from all patients, liver tissues from 14 patients with CHB, and hepatic perfusate from 8 liver donors were collected for immune analysis. Jurkat, THP-1 and HepG2.2.15 cell lines were used in cell experiments. The proportion of IFN-γ+ Th1 cells was higher in the cured group than in the uncured group, which was linearly correlated with HBsAg decline and alanine aminotransferase (ALT) levels during treatment. However, CD8+ T cells were weakly associated with HBsAg loss. Serum and intrahepatic levels of Th1 cell-associated chemokines (C-X-C motif chemokine ligand [CXCL] 9, CXCL10, CXCL11, IFN-γ) were significantly lower in the cured patients than in patients with a higher HBsAg quantification during therapy. Serum from cured patients induced more M1 (CD68+CD86+ macrophage) cells than that from uncured patients. Patients with chronic HBV infection had significantly lower proportions of CD86+ M1 and CD206+ M2 macrophages in their livers than healthy controls. M1 polarization of intrahepatic Kupffer cells promoted HBsAg loss by upregulating the effector function of tissue-resident memory T cells with increased ALT levels. IFN-γ+ Th1 activates intrahepatic resident memory T cells to promote HBsAg loss by inducing M1 macrophage polarization.

The orientation of CpG conjugation on aluminum oxyhydroxide nanoparticles determines the immunostimulatory effects of combination adjuvants.

In subunit vaccines, aluminum salts (Alum) are commonly used as adjuvants, but with limited cellular immune responses. To overcome this limitation, CpG oligodeoxynucleotides (ODNs) have been used in combination with Alum. However, current combined usage of Alum and CpG is limited to linear mixtures, and the underlying interaction mechanism between CpG and Alum is not well understood. Thus, we propose to chemically conjugate Alum nanoparticles and CpG (with 5' or 3' end exposed) to design combination adjuvants. Our study demonstrates that compared to the 3'-end exposure, the 5'-end exposure of CpG in combination adjuvants (Al-CpG-5') enhances the activation of bone-marrow derived dendritic cells (BMDCs) and promotes Th1 and Th2 cytokine secretion. We used the SARS-CoV-2 receptor binding domain (RBD) and hepatitis B surface antigen (HBsAg) as model antigens to demonstrate that Al-CpG-5' enhanced antigen-specific antibody production and upregulated cytotoxic T lymphocyte markers. Additionally, Al-CpG-5' allows for coordinated adaptive immune responses even at lower doses of both CpG ODNs and HBsAg antigens, and enhances lymph node transport of antigens and activation of dendritic cells, promoting Tfh cell differentiation and B cell activation. Our novel Alum-CPG strategy points the way towards broadening the use of nanoadjuvants for both prophylactic and therapeutic vaccines.

The lack of HBsAg secretion does neither facilitate induction of antiviral T cell responses nor Hepatitis B Virus clearance in mice.

Immune tolerance to the hepatitis B virus (HBV) is crucial for developing chronic hepatitis B, and the HBV surface antigen (HBsAg) produced and secreted in high amounts is regarded as a key contributor. HBsAg is expressed in HBV-infected hepatocytes and those carrying an HBV integration. Whether either HBsAg secretion or the high antigen amount expressed in the liver determines its immunomodulatory properties, however, remains unclear. We, therefore, developed a novel HBV animal model that allowed us to study the role of secreted HBsAg. We introduced a previously described HBs mutation, C65S, abolishing HBsAg secretion into a replication-competent 1.3-overlength HBV genome and used adeno-associated virus vectors to deliver it to the mouse liver. The AAV-HBV established a carrier state of wildtype and C65S mutant HBV, respectively. We investigated antiviral B- and T-cell immunity in the HBV-carrier mice after therapeutic vaccination. Moreover, we compared the effect of a lacking HBsAg secretion with that of an antiviral siRNA. While missing HBsAg secretion allowed for higher levels of detectable anti-HBs antibodies after therapeutic vaccination, it did neither affect antiviral T-cell responses nor intrahepatic HBV gene expression, irrespective of the starting level. A treatment with HBV siRNA restricting viral antigen expression within hepatocytes, however, improved the antiviral efficacy of therapeutic vaccination, irrespective of the ability of HBV to secrete HBsAg. Our data indicate that clearing HBsAg from blood cannot significantly impact HBV persistence or T-cell immunity. This indicates that a restriction of hepatic viral antigen expression will be required to break HBV immunotolerance.

Current and future use of antibody-based passive immunity to prevent or control HBV/HDV infections.

With the increasing momentum and success of monoclonal antibody therapy in conventional medical practices, there is a revived emphasis on the development of monoclonal antibodies targeting the hepatitis B surface antigen (anti-HBs) for the treatment of chronic hepatitis B (HBV) and hepatitis D (HDV). Combination therapies of anti-HBs monoclonal antibodies, and novel anti-HBV compounds and immunomodulatory drugs presenting a promising avenue to enhanced therapeutic outcomes in HBV/HDV cure regimens. In this review, we will cover the role of antibodies in the protection and clearance of HBV infection, the association of anti-HBV surface antigen antibodies (anti-HBs) in protection against HBV and how antibody effector functions, beyond neutralization, are likely necessary. Lastly, we will review clinical data from previous and ongoing clinical trials of passive antibody therapy to provide a state-of-the-are perspective on passive antibody therapies in combinations with additional novel agents.

Effect of S-region mutations on HBsAg in HBsAg-negative HBV-infected patients.

BACKGROUND: Occult HBV infection (OBI) is a special form of hepatitis B virus (HBV) infection that may cause Liver cirrhosis and hepatocellular carcinoma, causing significant harm to patients. Given the insidious nature of OBI, it is usually not easy to be detected. Most of the samples currently studied are concentrated on blood donors, however, patients in this special state have not been fully studied. This project aimed to study the effect of HBV S region mutations on HBsAg in patients with clinical OBI. METHODS: Collect 107 HBsAg-/HBV DNA + blood samples from Beijing Youan Hospital, Capital Medical University from August 2022 to April 2023. Next, the successfully extracted and amplified HBV DNA S regions were sequenced. Construct mutant plasmids to verify the cell function of the high-frequency mutation sites and explore the possible molecular mechanism. RESULTS: Sixty-eight HBsAg-negative samples were sequenced, revealing high-frequency amino acid substitution sites in the HBV S protein, including immune escape mutations (i.e., sY100C、sK122R、sI126T、sT131P、and sS114T) and TMD (Transmembrane domain) region substitutions (i.e., sT5A、sG10D、sF20S、and sS3N). We constructed a portion of the mutant plasmids and found that sT5A, sF20S, sG10D, sS3N, sI68T, and sI126T single point mutations or combined mutations may decrease HBsAg expression or change the antigenicity of HBsAg leading to detection failure. CONCLUSIONS: HBsAg-negative patients may show various mutations and amino acid replacement sites at high frequency in the HBV S-region, and these mutations may lead to undetectable Hepatitis B surface antigen (HBsAg), HBsAg antigenic changes or secretion inhibition.

Dismantling Barriers to Hepatitis B and Delta Screening, Prevention, and Linkage to Care among the PWUD Community in Philadelphia.

The prevalence of hepatitis B and delta viruses (HBV/HDV) among people who use drugs (PWUD) remains largely unknown. In the context of one Philadelphia-based harm reduction organization (HRO), this study aimed to assess HBV/HDV prevalence and facilitate linkage to care. Participants completed a demographic HBV/HDV risk factor survey and were screened for HBV and reflexively for HDV if positive for HBV surface antigen or isolated core antibody. Fisher's exact tests and regression were used to understand relationships between risks and HBV blood markers. Of the 498 participants, 126 (25.3%) did not have hepatitis B immunity, 52.6% had been vaccinated against HBV, and 17.9% had recovered from a past infection. Eleven (2.2%) participants tested positive for isolated HBV core antibody, 10 (2.0%) for HBV surface antigen, and one (0.2%) for HDV antibody. History of incarceration was associated with current HBV infection, while transactional sex and experience of homelessness were predictive of previous exposure. This study found high rates of current and past HBV infection, and a 10% HBV/HDV co-infection rate. Despite availability of vaccine, one quarter of participants remained vulnerable to infection. Findings demonstrate the need to improve low-threshold HBV/HDV screening, vaccination, and linkage to care among PWUD. The study also identified gaps in the HBV/HDV care cascade, including lack of point-of-care diagnostics and lack of support for HROs to provide HBV services.

Immunogenicity of Wild Type and Mutant Hepatitis B Surface Antigen Virus-like Particles (VLPs) in Mice with Pre-Existing Immunity against the Wild Type Vector.

Virus-like particles (VLPs), composed of the small hepatitis B virus surface antigen (HBsAgS), are the antigenic components of the hepatitis B virus (HBV) vaccine and represent the backbones for a chimeric anti-malaria vaccine and various vaccine candidates. Biological vectors have to face pre-existing anti-vector immune responses due to previous immune exposure. Vector recognition after natural infections or vaccinations can result in unwarranted outcomes, with compromising effects on clinical outcomes. In order to evaluate the impact of a pre-existing anti-HBsAgS immune response, we developed mutant VLPs composed of subunits with reduced HBsAgS-specific antigenicity. The insertion of a Plasmodium falciparum circumsporozoite protein (CSP)-derived epitope as a read-out allowed the assessment of wild type (wt) and mutant VLPs in the context of a pre-existing immune response. Mutant and wt VLP platforms with a CSP-epitope insert are immunogenic and have the ability to generate anti-CSP antibody responses in both naïve BALB/c mice and mice with a pre-existing anti-HBsAgS immune response, but with superior anti-CSP responses in mice with a pre-existing immunity. The data indicate that previous HBsAgS exposure facilitates enhanced antibody responses against foreign epitopes delivered by the HBsAgS platform, and, in this context, the state of immune sensitization alters the outcome of subsequent vaccinations.

Baseline Hepatitis B Virus Surface Antigen Titers in Childhood Predict the Risk of Advanced Liver Fibrosis in Adulthood.

BACKGROUND & AIMS: Hepatitis B virus (HBV) surface antigen (HBsAg) is a marker of both HBV covalently closed circular DNA and integrated HBV genome, whereas the HBV core-related antigen (HBcrAg) indicates the transcriptional activity of covalently closed circular DNA. This study examined the relationship between HBsAg and HBcrAg titers in childhood and advanced fibrosis in adulthood. METHODS: We recruited 214 initially hepatitis B e antigen-positive chronic HBV-infected patients who were followed for a total of 6371 person-years. None of the patients were co-infected with hepatitis C or D virus. Serum HBsAg and HBcrAg titers were assessed at 10 and 15 years of age. Transient elastography was performed at a mean final age of 38.21 years to identify advanced fibrosis. RESULTS: Patients with advanced fibrosis in adulthood had a higher rate of genotype C HBV infection and a higher HBsAg titer at 10 and 15 years of age (P = .003, P = .03, and P = .005, respectively). The HBcrAg titer was not correlated with advanced fibrosis (P > .05). Receiver operating characteristic curve analysis showed that HBsAg cutoffs of >4.23 and >4.44 log10 IU/mL at 10 and 15 years of age, respectively, best predicted advanced fibrosis in the fourth decade of life (P = .001 and P < .001, respectively). In a multivariate analysis, both an HBsAg titer >4.44 log10 IU/mL at 15 years of age and HBV genotype C were predictors of advanced fibrosis (odds ratios, 15.43 and 4.77; P = .01 and P = .02, respectively). CONCLUSIONS: HBsAg titers in childhood predict the progression to liver fibrosis in adulthood.

Biologic Therapy Carries a Very Low Risk of Reactivation in Hepatitis B Surface Antigen-Negative Phase of Hepatitis B.

BACKGROUND: The risk of hepatitis B reactivation in hepatitis B surface antigen-negative phase of hepatitis B virus-infected patients exposed to biologic agents is not clear. We aimed to investigate the reactivation rate in hepatitis B surface antigen-negative phase of hepatitis B virus-infected patients after biologic therapy. METHODS: Patients followed at gastroenterology, rheumatology, and dermatology clinics with a diagnosis of immune-mediated inflam matory diseases were screened. Immune-mediated inflammatory diseases patients exposed to biologic agents with a negative hepatitis B surface antigen and positive hepatitis B core immunoglobulin G antibody were included in the study. RESULTS: We screened 8266 immune-mediated inflammatory disease patients, and 2484 patients were identified as exposed to biologic agents. Two hundred twenty-one patients were included in the study. The mean age was 54.08 ± 11.69 years, and 115 (52.0%) patients were female. The median number of different biologic subtype use was 1 (range: 1-6). The mean biologic agent exposure time was 55 (range: 2-179) months. One hundred and fifty-two (68.8%) patients used a concomitant immunomodulatory agent, and 84 (38.0%) patients were exposed to corticosteroids during biologic use. No hepatitis B reactivation with a reverse seroconversion of hepatitis B surface antigen positivity was seen. Antiviral prophylaxis for hepatitis B was applied to 48 (21.7%) patients. Hepatitis B virus-DNA was screened in 56 (25.3%) patients prior to the biologic exposure. Two patients without antiviral prophylaxis had hepatitis B virus-DNA reactivation with a negative hepatitis B surface antigen during exposure to the biologic agent. CONCLUSION: We found 2 reactivations and no hepatitis B surface antigen seroconversion in our cohort. Antiviral prophylaxis for patients exposed to biologic agents may need to be discussed in more detail.

Isolated Hepatitis B Core Antibody Positivity and Long-Term Liver-Related Mortality in Korea: A Cohort Study.

INTRODUCTION: Whether isolated hepatitis B core antibody (anti-HBc) positivity is a risk factor for long-term liver-related outcomes in hepatitis B virus (HBV)-endemic areas remains unclear. We aimed to investigate liver-related and liver cancer mortality of isolated anti-HBc positivity in Korean adults. METHODS: A cohort study comprised 609,299 Korean adults who underwent hepatitis B serologic markers, as a part of health examination. Liver-related and liver cancer mortality were determined using the National Death Records. RESULTS: During a median follow-up of 9.0 years (interquartile range, 5.5-13.7 years), 554 liver-related deaths were identified (liver-related mortality, 9.6 cases per 10 5 person-years). The prevalence of isolated anti-HBc positivity was 3.8% (n = 23,399) and was age-dependent. After adjustment for age, sex, and other confounders, hazard ratios (95% confidence interval) for liver-related mortality in isolated anti-HBc-positive and hepatitis B surface antigen-positive subjects compared with HBV-unexposed subjects were 1.69 (1.22-2.33) and 27.02 (21.45-34.04), respectively. These associations were pronounced in the analyses using liver cancer mortality as an outcome. Among isolated anti-HBc-positive patients, the risks of liver-related and liver cancer mortality were significantly higher in those with high fibrosis-4 scores compared with patients unexposed to HBV with the multivariable-adjusted hazard ratios (95% confidence interval) of 15.59 (9.21-26.37) and 72.66 (36.96-142.86), respectively. DISCUSSION: In this cohort of Korean adults, isolated anti-HBc positivity was associated with an increased risk of liver-related and liver cancer mortality, especially when accompanied by a high fibrosis score. Isolated anti-HBc positivity may be an independent risk factor for liver-related outcomes, especially in high-endemic areas.

Multiple epitopes of hepatitis B virus surface antigen targeted by human plasma-derived immunoglobulins coincide with clinically observed escape mutations.

Hepatitis B immune globulin (HBIG) is a human plasma-derived immunoglobulin G concentrate that contains a high titer of neutralizing antibodies (anti-HBs) to the hepatitis B virus (HBV) surface antigen (HBsAg). HBIG is known to be highly effective in treating HBV infections, however, a more systematic characterization of the antibody binding sites on HBsAg and their correlation with emerging "escape" mutations in HBsAg was lacking. By using anti-HBs antibodies from HBIG lots to screen random peptide phage display libraries, we identified five clusters of peptides that corresponded to five distinct anti-HBs binding sites on the HBsAg. Three sites, Site II (C121-C124), Site III (M133-P135), and Site IV (T140-G145), were mapped within the "a" determinant, while the two other sites, Site I (Q101-M103) and Site V (I152-S154), were outside the "a" determinant. We then tested in binding assays HBsAg peptides containing clinically relevant mutations previously reported within these sites, such as Y134S, P142S, and G145R, and observed a significant reduction in anti-HBs binding activity to the mutated sites, suggesting a mechanism the virus may use to avoid HBIG-mediated neutralization. The current HBIG treatment could be improved by supplementing it with site-specific neutralizing monoclonal antibodies that target these mutations for control of HBV infections.

Incidence and prediction of HBsAg seroclearance in a prospective multi-ethnic HBeAg-negative chronic hepatitis B cohort.

BACKGROUND AND AIMS: Achieving HBsAg loss is an important landmark in the natural history of chronic hepatitis B (CHB). A more personalized approach to prediction of HBsAg loss is relevant in counseling patients. This study sought to develop and validate a prediction model for HBsAg loss based on quantitative HBsAg levels (qHBsAg) and other baseline characteristics. METHODS: The Hepatitis B Research Network (HBRN) is a prospective cohort including 1240 untreated HBeAg-negative patients (1150 adults, 90 children) with median follow-up of 5.5 years. Incidence rates of HBsAg loss and hepatitis B surface antibody (anti-HBs) acquisition were determined, and a predictor score of HBsAg loss using readily available variables was developed and externally validated. RESULTS: Crude incidence rates of HBsAg loss and anti-HBs acquisition were 1.6 and 1.1 per 100 person-years (PY); 67 achieved sustained HBsAg loss for an incidence rate of 1.2 per 100 PY. Increased HBsAg loss was significantly associated with older age, non-Asian race, HBV phenotype (inactive CHB vs. others), HBV genotype A, lower HBV-DNA levels, and lower and greater change in qHBsAg. The HBRN-SQuARe (sex,∆quantHBsAg, age, race) score predicted HBsAg loss over time with area under the receiver operating characteristic curve (AUROC) (95% CIs) at 1 and 3 years of 0.99 (95% CI: 0.987-1.00) and 0.95 (95% CI 0.91-1.00), respectively. In validation in another cohort of 1253 HBeAg-negative patients with median follow-up of 3.1 years, HBRN SQuARe predicted HBsAg loss at 1 and 3 years with AUROC values of 0.99 (0.98-1.00) and 0.88 (0.77-0.99), respectively. CONCLUSION: HBsAg loss in predominantly untreated patients with HBeAg-negative CHB can be accurately predicted over a 3-year horizon using a simple validated score (HBRN SQuARe). This prognostication tool can be used to support patient care and counseling.