Coexistence of Hepatitis B Surface Antigen (HBsAg) and Heterologous Subtype-Specific Antibodies to HBsAg among Patients with Chronic Hepatitis B Virus Infection

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.

Patterns of hepatitis b virus immune escape and pol/rt mutations across clinical cohorts of patients with genotypes a, e and occult hepatitis b infection in Nigeria: A multi-centre study

Hepatitis B virus (HBV) immune escape and Pol/RT mutations account for HBV immunoprophylactic, therapeutic, and diagnostic failure globally. Little is known about circulating HBV immune escape and Pol/RT mutants in Nigeria. This study focused on narrowing the knowledge gap of the pattern and prevalence of the HBV mutants across clinical cohorts of infected patients in southwestern Nigeria. Ninety-five enrollees were purposively recruited across clinical cohorts of HBV-infected patients with HBsAg or anti-HBc positive serological outcome and occult HBV infection. Total DNA was extracted from patients' sera. HBV S and Pol gene-specific nested PCR amplification was carried out. The amplicons were further sequenced for serotypic, genotypic, phylogenetic, and mutational analysis. HBV S and Pol genes were amplified in 60 (63.2%) and 19 (20%) of HBV isolates, respectively. All the sixty HBV S gene and 14 of 19 Pol gene sequences were exploitable. The ayw4 serotype was predominant (95%) while ayw1 serotype was identified in 5% of isolates. Genotype E predominates in 95% of sequences, while genotype A, sub-genotype A3 was observed in 5%. Prevalence of HBV IEMs in the "a" determinant region was 29%. Commonest HBV IEM was S113T followed by G145A and D144E. The Pol/RT mutations rtV214A and rtI163V among others were identified in this study. This study provided data on the occurrence of existing and new HBV IEMs and Pol gene mutations in Nigeria.

Unusual serological profile in hepatitis B virus (HBV) infection associated with a probable clinical case of acute exacerbation of pre-existing chronic HBV infection

BACKGROUND

Acute or chronic HBV infection in an individual can be laboratory characterized according to the serological profile of the viral markers in the bloodstream, and the dynamics monitoring of these markers is necessary to assess the disorder course and the infection outcome. However, under certain circumstances unusual or atypical serological profiles may be observed in both acute and chronic HBV infection. They are considered as such because they do not properly characterize the form or infection clinical phase or because they seem inconsistent, considering the viral markers dynamics in both clinical contexts. This manuscript comprises the analysis of an unusual serological profile in HBV infection.

METHODS AND RESULTS

This clinical-laboratory study, had as reference a patient who presented clinical profile suggestive of acute HBV infection after recent exposure, whose laboratory data were initially compatible with this clinical presentation. However, the serological profile analysis and its monitoring demonstrated unusual pattern of viral markers expression, which has been observed in several clinical contexts, and is often associated a number of agent- or host-related factors.

CONCLUSION

The serological profile analyzed here, associated with the biochemical markers serum levels found, is indicative of active chronic infection, consequence of viral reactivation. This finding suggests that in the event of unusual serological profiles in HBV infection, if the influence of agent- or host-related factors is not properly considered and neither the viral markers dynamics properly analyzed, there may be mistake in the infection clinical diagnosis, especially when the patient's clinical and epidemiological history is unknown.

A Novel Insertion in the Hepatitis B Virus Surface Protein Leading to Hyperglycosylation Causes Diagnostic and Immune Escape

Chronic hepatitis B virus (HBV) infection is a global health threat. Mutations in the surface antigen of HBV (HBsAg) may alter its antigenicity, infectivity, and transmissibility. A patient positive for HBV DNA and detectable but low-level HBsAg in parallel with anti-HBs suggested the presence of immune and/or diagnostic escape variants. To support this hypothesis, serum-derived HBs gene sequences were amplified and cloned for sequencing, which revealed infection with exclusively non-wildtype HBV subgenotype (sgt) D3. Three distinct mutations in the antigenic loop of HBsAg that caused additional N-glycosylation were found in the variant sequences, including a previously undescribed six-nucleotide insertion. Cellular and secreted HBsAg was analyzed for N-glycosylation in Western blot after expression in human hepatoma cells. Secreted HBsAg was also subjected to four widely used, state-of-the-art diagnostic assays, which all failed to detect the hyperglycosylated insertion variant. Additionally, the recognition of mutant HBsAg by vaccine- and natural infection-induced anti-HBs antibodies was severely impaired. Taken together, these data suggest that the novel six-nucleotide insertion as well as two other previously described mutations causing hyperglycosylation in combination with immune escape mutations have a critical impact on in vitro diagnostics and likely increase the risk of breakthrough infection by evasion of vaccine-induced immunity.

Atypical serologic profiles of hepatitis B virus infection across clinical cohorts of patients in Southwestern Nigeria

Hepatitis B virus (HBV) infection follows a natural course of events predicted by a dynamic interaction between viral antigen and the host immune system, which forms the basis for HBV serological diagnosis. These interactions may deviate from the typical serologic patterns. This study investigates the types of atypical HBV serologic profiles (AHBSP) across clinical cohorts of patients with HBV infection in southwestern Nigeria. This is a cross-sectional, hospital-based, multi-centered study. Patients' sera were analyzed for HBsAg, anti-HBs, HBeAg, anti-HBe, anti-HBc IgM, and anti-HBc IgG by ELISA from 279 study participants attending selected gastroenterology clinics between August 2019 and December 2020. The prevalence of atypical HBV serologic profiles was 27% (n = 76). The mean age of patients was 35.7 ± 11.2 years. The gender distribution involved 183 females (65.6%) and 96 males (34.4%). Across clinical cohorts of patients with atypical serologic profiles, HBeAg Negative, anti-HBe positive with detectable HBV DNA had the highest prevalence of 21% followed by isolated anti-HBc antibody positive, HBsAg negative and detectable HBV DNA, 5%. The atypical serologic profiles, HBeAg positive, HBsAg negative with detectable HBV DNA and concurrent anti-HBs with HBsAg, had the lowest prevalence, 0.4%, respectively. This study identified the considerable presence of atypical HBV serologic profiles across clinical cohorts of HBV infection in southwestern Nigeria.

Reactivation of occult hepatitis B virus infection in a renal transplant recipient

We report a case of hepatitis B virus (HBV) reactivation in a renal transplant recipient. Reactivation manifested as an occult infection with detectable HBV-DNA and negativity for hepatitis B surface antigen (HBsAg). The anti-HBs antibody titre was above the protective threshold and continued to rise, to 951.36 mIU/ml, after HBV reactivation. Sequencing revealed multiple vaccine- and diagnostic-escape mutations in the major hydrophilic region of HBsAg. This case demonstrates both reactivation of an HBV escape mutant in a vaccinated patient and host immunity after virus mutation.

T-Cell Receptor β Chain and B-Cell Receptor Repertoires in Chronic Hepatitis B Patients with Coexisting HBsAg and Anti-HBs

Antibodies in response to antigens are related to the immune repertoire of T- and B-cell receptors. However, some patients with chronic hepatitis B (CHB) have coexisting HBsAg and anti-HBsAg antibodies (anti-HBs) that cannot neutralize HBV. We attempted to investigate the repertoires that produce this response in CHB patients. The T-cell receptor β chain (TRB) and B-cell receptor (BCR) repertoires of peripheral blood genomic DNA were analyzed using MiXCR. T-cell receptor (TCR) cluster analysis was carried out by clusTCR, and motifs prediction was selected by Multiple Em for Motif Elicitation (MEME). A total of 76 subjects were enrolled, including 26 HBsAg and anti-HBs coexisting patients with CHB (DP group), 25 anti-HBs single-positive healthy people (SP group), and 25 CHB patients (CHB group). The clone length of BCR in 39, 90 was significantly different among these groups (p = 0.005, 0.036). The motif “CASSLG” in the DP group was significantly higher than SP and CHB groups and may relate to coexistence, and the motif “GAGPLT” was only shown in the SP group and may relate to anti-HB expression. These provide important insights into vaccine development and CHB treatment.

T-Cell Receptor β Chain and B-Cell Receptor Repertoires in Chronic Hepatitis B Patients with Coexisting HBsAg and Anti-HBs

Antibodies in response to antigens are related to the immune repertoire of T- and B-cell receptors. However, some patients with chronic hepatitis B (CHB) have coexisting HBsAg and anti-HBsAg antibodies (anti-HBs) that cannot neutralize HBV. We attempted to investigate the repertoires that produce this response in CHB patients. The T-cell receptor β chain (TRB) and B-cell receptor (BCR) repertoires of peripheral blood genomic DNA were analyzed using MiXCR. T-cell receptor (TCR) cluster analysis was carried out by clusTCR, and motifs prediction was selected by Multiple Em for Motif Elicitation (MEME). A total of 76 subjects were enrolled, including 26 HBsAg and anti-HBs coexisting patients with CHB (DP group), 25 anti-HBs single-positive healthy people (SP group), and 25 CHB patients (CHB group). The clone length of BCR in 39, 90 was significantly different among these groups (p = 0.005, 0.036). The motif “CASSLG” in the DP group was significantly higher than SP and CHB groups and may relate to coexistence, and the motif “GAGPLT” was only shown in the SP group and may relate to anti-HB expression. These provide important insights into vaccine development and CHB treatment.

Association of Coexistent Hepatitis B Surface Antigen and Antibody With Severe Liver Fibrosis and Cirrhosis in Treatment-Naive Patients With Chronic Hepatitis B

IMPORTANCE

Coexistence of hepatitis B surface antigen (HBsAg) and antibody against HBsAg (anti-HBs) constitutes an atypical serological profile in chronic hepatitis B virus infection, and the association between coexistent HBsAg and anti-HBs with severe liver fibrosis and cirrhosis in patients with chronic hepatitis B (CHB) remains unclear.

OBJECTIVE

To investigate the association of coexistent HBsAg and anti-HBs with severe liver fibrosis and cirrhosis in patients with CHB.

DESIGN, SETTING, AND PARTICIPANTS

Consecutive treatment-naive patients with CHB from 2 medical institutions in China were enrolled between January 10, 2015, and March 31, 2021. Severe liver fibrosis and cirrhosis were identified using the aspartate transaminase (AST) to platelet ratio index (APRI), the fibrosis index based on 4 factors (FIB-4; factors comprise age, AST level, alanine aminotransferase [ALT] level, and platelet count), transient elastography, or ultrasonography. Data were analyzed from August 1, 2021, to April 15, 2022.

MAIN OUTCOMES AND MEASURES

The primary outcomes were rates of severe liver fibrosis and cirrhosis among patients with vs patients without coexistant HBsAg and anti-HBs. Severe liver fibrosis was defined as an APRI score of 1.5 or higher, a FIB-4 score of 3.25 or higher, or a liver stiffness measurement of 8 kPa or higher; cirrhosis was defined as an APRI score of 2.0 or higher, a FIB-4 score of 6.5 or higher, a liver stiffness measurement of 11 kPa or higher, or ultrasonographic findings suggestive of cirrhosis.

RESULTS

Of 6534 enrolled patients, 4033 patients (61.7%) were male, and the median (IQR) age was 41.0 (33.0-52.0) years. A total of 277 patients (4.2%) had coexistent HBsAg and anti-HBs. Patients with vs without anti-HBs were older (median [IQR], 46.0 [33.0-55.5] years vs 41.0 [33.0-52.0] years) and had a higher proportion of hepatitis B e antigen (HBeAg) positivity (123 of 277 patients [44.4%] vs 2115 of 6257 patients [33.8%]; P < .001), higher ALT levels (median [IQR], 45.1 [24.6-119.0] U/L vs 36.7 [22.0-77.0] U/L; P = .001) and AST levels (median [IQR], 35.0 [23.5-68.4] U/L vs 28.3 [21.6-51.0] U/L; P < .001), and lower platelet counts (median [IQR], 173.0 × 103/μL [129.0-212.5 × 103/μL] vs 185.0 × 103/μL [141.0-224.0 × 103/μL]; P = .004), albumin levels (median [IQR], 4.37 [4.11-4.56] g/dL vs 4.43 [4.17-4.61] g/dL; P = .02), and HBsAg levels (median [IQR], 2.8 log10 [1.6-3.4 log10] IU/mL vs 3.3 log10 [2.6-3.9 log10] IU/mL; P < .001). Compared with patients without anti-HBs, those with anti-HBs had higher APRI scores (median [IQR], 0.5 [0.3-1.4] vs 0.4 [0.3-0.9]; P < .001), FIB-4 scores (median [IQR], 1.4 [0.9-2.6] vs 1.1 [0.7-2.1]; P < .001), and liver stiffness values (median [IQR], 7.5 [6.2-9.8] kPa vs 6.3 [5.2-8.1] kPa; P = .003). Patients with anti-HBs also had higher proportions of severe liver fibrosis (102 of 277 patients [36.8%] vs 1397 of 6207 patients [22.5%]; P < .001) and cirrhosis (87 of 277 patients [31.4%] vs 1194 of 6213 patients [19.2%]; P < .001) compared with patients without anti-HBs. The coexistence of HBsAg and anti-HBs was independently associated with severe liver fibrosis (odds ratio [OR], 2.29; 95% CI, 1.56-3.38; P < .001) and cirrhosis (OR, 1.73; 95% CI, 1.12-2.68; P = .01) in the multivariate analysis. However, the association of coexistent HBsAg and anti-HBs with cirrhosis was only observed in patients with HBeAg negativity (OR, 1.66; 95% CI, 1.05-2.62; P = .03) and not in patients with HBeAg positivity (OR, 1.45; 95% CI, 0.87-2.43; P = .16).

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, the coexistence of HBsAg and anti-HBs was unusual in hepatitis B virus infection and was associated with more advanced liver diseases, such as severe liver fibrosis and cirrhosis, especially among patients with HBeAg negativity. These results suggest that close monitoring for liver fibrosis and cirrhosis is warranted in patients with CHB who have this serological profile.

The Impact of HBV Quasispecies Features on Immune Status in HBsAg+/HBsAb+ Patients With HBV Genotype C Using Next-Generation Sequencing

Background

This study aimed to explore the molecular mechanism of the coexistence of hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (HBsAb) serological pattern via intensive characterization of HBV s gene in both chronic hepatitis B (CHB) and hepatocellular carcinoma (HCC) patients.

Method

A total of 73 HBsAg+/HBsAb+ patients (CHB = 36, HCC = 37) and 96 HBsAg+/HBsAb− patients (CHB = 47, HCC = 49) were enrolled from 13 medical centers in China. The sequence features were elaborated based on the combination of next-generation sequencing (NGS) and multidimensional bioinformatics analysis.

Results

The 16 high-frequency missense mutations, changes of stop codon mutation, clustering, and random forest models based on quasispecies features demonstrated the significant discrepancy power between HBsAg+/HBsAb+ and HBsAg+/HBsAb− in CHB and HCC, respectively. The immunogenicity for cytotoxic T lymphocyte (CTL) epitope Se and antigenicity for the major hydrophilic region (MHR) were both reduced in HBsAg+/HBsAb+ patients (CTL Se: p < 0.0001; MHR: p = 0.0216). Different mutation patterns were observed between HBsAg+/HBsAb+ patients with CHB and with HCC. Especially, mutations in antigenic epitopes, such as I126S in CHB and I126T in HCC, could impact the conformational structure and alter the antigenicity/immunogenicity of HBsAg.

Conclusion

Based on NGS and bioinformatics analysis, this study indicates for the first time that point mutations and quasispecies diversities of HBV s gene could alter the MHR antigenicity and CTL Se immunogenicity and could contribute to the concurrent HBsAg+/HBsAb+ with different features in HCC and CHB. Our findings might renew the understanding of this special serological profile and benefit the clinical management in HBV-related diseases.

Current laboratory tests for diagnosis of hepatitis B virus infection

BACKGROUND

Hepatitis B virus (HBV) has a long history in human infectious diseases. HBV infection can progress chronically, leading to cancer. After introduction of a vaccine, the overall incidence rate of HBV infection has decreased, although it remains a health problem in many countries.

PURPOSE

The aim of this review was to summarise current diagnostic efforts for HBV infection and future HBV diagnosis perspectives.

METHODS

We reviewed and summarised current laboratory diagnosis related with HBV infection in clinical practice.

RESULTS

There have been various serologic- and molecular-based methods to diagnose acute or chronic HBV infection. Since intrahepatic covalently closed circular DNAs (cccDNAs) function as robust HBV replication templates, cure of chronic HBV infection is limited. Recently, new biomarkers such as hepatitis B virus core-related antigen (HBcrAg) and HBV RNA have emerged that appear to reflect intrahepatic cccDNA status. These new biomarkers should be validated before clinical usage.

CONCLUSION

An effective diagnostic approach and current updated knowledge of treatment response monitoring are important for HBV infection management. Brand new ultrasensitive and accurate immunologic methods may pave the way to manage HBV infection in parallel with immunotherapy era.

Analysis of serum hepatitis B virus RNA levels among HBsAg and HBsAb copositive patients and its correlation with HBV DNA

ABSTRACT

There are approximately 2 billion HBV-infected individuals worldwide, and approximately 1.87% to 7% of these individuals are copositive for HBsAg and HBsAb.Our study detected hepatitis B virus pgRNA (HBV RNA) levels in HBsAg and HBsAb copositive patients and then analyzed the correlation with HBV DNA, HBsAg, ALT, and AST levels. A total of 149 HBsAg and HBsAb copositive patients were identified from 66,617 outpatients.HBV RNA, HBV DNA, HBsAg, ALT, and AST serum levels were significantly different in different natural phases of HBV infection (immune tolerance phase, immune clearance phase, low replication phase, and reactivation phase) with statistical significance (P < .01). HBV RNA levels were positively correlated with HBV DNA, HBsAg, ALT, and AST levels. HBV RNA and HBV DNA levels were significantly increased in the HBeAg-positive group (66 patients) compared with the HBeAg-negative group (83 patients) (P < .01). In the HBeAg-positive group, HBV RNA levels were positively correlated with HBV DNA and HBsAg levels. In the HBeAg-negative group, HBV RNA levels were positively correlated with HBV DNA. Serum HBV RNA levels were positively correlated with HBV DNA, HBsAg, ALT, and AST levels.HBV RNA could be used as a virological indicator for antiviral therapy in HBsAg and HBsAb copositive hepatitis B patients.

Paradoxical HBsAg and anti-HBs coexistence among Chronic HBV Infections: Causes and Consequences

Hepatitis B surface antigen (HBsAg) and Hepatitis B surface antibody (anti-HBs) were reported simultaneously among Hepatitis B virus (HBV) infections. HBsAg is a specific indicator of acute or chronic HBV infections, while anti-HBs is a protective antibody reflecting the recovery and immunity of hosts. HBsAg and anti-HBs coexist during seroconversion and then form immune complex, which is rare detected in clinical cases. However, with the promotion of vaccination and the application of various antiviral drugs, along with the rapid development of medical technology, the coexistence of HBsAg and anti-HBs has become more prevalent. Mutations in the viral genomes, immune status and genetic factors of hosts may contribute to the coexistence. Novel HBsAg assays, with higher sensitivity and ability to detect mutations or immune complexes, can also yield HBsAg/anti-HBs coexistence. The discovery of coexistence has shattered the idea of traditional serological patterns and raised questions about the effectiveness of vaccines. Worth noting is that HBsAg/anti-HBs double positivity is strongly associated with progressive liver diseases, especially hepatocellular carcinoma. In conclusion, viral mutations, host factors, and methodology impacts can all lead to the coexistence of HBsAg and anti-HBs. This coexistence is not an indicator of improvement, as an increased risk of adverse clinical outcomes still exists.

Characteristics of amino acid substitutions within the "a" determinant region of hepatitis B virus in chronically infected patients with coexisting HBsAg and anti-HBs

OBJECTIVES

Simultaneous positivity for both hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) is an atypical serological profile in chronic hepatitis B (CHB) patients. The exact mechanisms underlying the uncommon profile remains unclear. The aim of this study was to analyze the characteristics of amino acid substitutions within the "a" determinant region in a large cohort of CHB patients with coexistence of HBsAg and anti-HBs.

METHODS

In total 8687 CHB patients, of which 505 had coexisting HBsAg and anti-HBs, were enrolled in this study. Mutations within the "a" determinant region in 131 HBsAg+/anti-HBs+ patients and 150 age and gender matched HBsAg+/anti-HBs- patients were determined by direct sequencing and the characteristics of amino acid substitutions were analyzed.

RESULTS

The prevalence of coexistence of HBsAg and anti-HBs in the CHB patients was 5.81%. Compared to the control subjects, there were more amino acid substitutions in HBsAg+/anti-HBs+ patients (30.5% vs. 12.7%, P<0.001), especially within the first loop of the "a" determinant region. The most frequent amino acid substitution was located at position s126 and the predominant substitution was sI126T in HBsAg+/anti-HBs+ patients with genotype C. The frequency of additional N-glycosylation sites in HBsAg+/anti-HBs+ patients and the control subjects was 3.8% and 0.6%, respectively.

CONCLUSIONS

The accumulation and diversity of amino acid variations within "a" determinant region might contribute to the coexistence of HBsAg and anti-HBs. These findings extend understanding of the genetic mechanism of this atypical serological profile in CHB patients.

Prevalence and clinical features of patients with concurrent HBsAg and anti-HBs: Evaluation of the hepatitis B research network cohort

The prevalence of concurrent HBsAg and anti-HBs in plasma of persons with chronic hepatitis B virus (HBV) infection is variable and its clinical significance enigmatic. We examined the prevalence and clinical and virological features of concurrent HBsAg and anti-HBs in children and adults with chronic HBV infection living in North America. A total of 1462 HBsAg positive participants in the Hepatitis B Research Network paediatric and adult cohorts were included (median age 41 (range 4-80) years, 48% female, 11% white, 13% black, 73% Asians). Only 18 (1.2%) were found to be anti-HBs positive (≥10 mIU/mL) at initial study evaluation. Distributions of sex, race, HBV genotype and ALT were similar between participants with and without concurrent anti-HBs. Those who were anti-HBs positive appeared to be older (median age 50 vs 41 years, P = .06), have lower platelet counts (median 197 vs 222 × 103/mm³ , P = .07) and have higher prevalence of HBeAg (44% vs 26%, P = .10). They also had lower HBsAg levels (median 2.0 vs 3.5 log₁₀ IU/mL, P = .02). Testing of follow-up samples after a median of 4 years (range 1-6) in 12 of the 18 participants with initial concurrent anti-HBs showed anti-HBs became undetectable in 6, decreased to <10 mIU/mL in 1 and remained positive in 5 participants. Two patients lost HBsAg during follow-up. In conclusion, prevalence of concurrent HBsAg and anti-HBs was low at 1.2%, with anti-HBs disappearing in some during follow-up, in this large cohort of racially diverse children and adults with chronic HBV infection living in North America. Presence of concurrent HBsAg and anti-HBs did not identify a specific phenotype of chronic hepatitis B, nor did it appear to affect clinical outcomes.

Entecavir Plus Pegylated Interferon and Sequential HBV Vaccination Increases HBsAg Seroclearance: A Randomized Controlled Proof-of-Concept Study

BACKGROUND

HBsAg seroclearance is considered a functional cure for patients with chronic hepatitis B, but is rarely achievable with oral nucleos(t)ide analogs alone. We conducted a randomized controlled proof-of-concept trial to evaluate the impact of adding pegylated interferon (Peg-IFN) alfa-2a plus sequential or concomitant hepatitis B virus (HBV) vaccination.

METHODS

A total of 111 patients who achieved serum HBV DNA <20 IU/mL and quantitated HBsAg (qHBsAg) <3,000 IU/mL with entecavir were randomly assigned (1:1:1) to the E+sVIP group (entecavir + Peg-IFN alfa-2a [180 µg every week over 48 weeks] + sequential HBV vaccination [20 µg of HBsAg on weeks 52, 56, 60, and 76]), E+cVIP group (entecavir + Peg-IFN alfa-2a + concomitant HBV vaccination [weeks 4, 8, 12, and 28]), or the control group (entecavir only). The primary endpoint was HBsAg seroclearance at week 100 and secondary endpoints included safety.

RESULTS

No differences in baseline qHBsAg were observed among the groups. The E+sVIP group in the intention-to-treat analysis showed a significantly higher chance of HBsAg seroclearance during week 100 than the control group (16.2% vs. 0%, P=0.025), but the E+cVIP group (5.4%) failed to reach a significant difference (P=0.54). Adverse events were significantly more frequent in the E+sVIP (81.1%) or E+cVIP group (70.3%) than the control group (2.7%) (both P<0.0001). However, the frequency of serious adverse events did not differ significantly among three groups (2.7%, 5.4%, and 2.7%, respectively; P=1.00).

CONCLUSIONS

Entecavir plus an additional Peg-IFN alfa-2a treatment followed by sequential HBV vaccination under an intensified schedule significantly increases the chance of HBsAg seroclearance compared to entecavir alone.

Complete genome analysis of hepatitis B virus in Qinghai-Tibet plateau: the geographical distribution, genetic diversity, and co-existence of HBsAg and anti-HBs antibodies

Background

The genetic variation and origin of Hepatitis B Virus (HBV) in Qinghai-Tibet Plateau were poorly studied. The coexistence of HBsAg and anti-HBs has been described as a puzzle and has never been reported in the indigenous population or in recombinant HBV sequences. This study aimed to report geographical distribution, genetic variability and seroepidemiology of HBV in southwest China.

Methods

During 2014–2017, 1263 HBsAg positive serum were identified and 183 complete genome sequences were obtained. Serum samples were collected from community-based populations by a multistage random sampling method. Polymerase chain reaction (PCR) was used to amplify the HBV complete genome sequences. Then recombination, genetic variability, and serological analysis were performed.

Results

(1) Of the 1263 HBsAg positive serum samples, there were significant differences between the distribution of seromarkers in Tibet and Qinghai. (2) Of 183 complete genome sequences, there were 130 HBV/CD1 (71.0%), 49 HBV/CD2 (26.8%) and four HBV/C2 isolates (2.2%). Serotype ayw2 (96.1%) was the main serological subtype. (3) Several nucleotide mutations were dramatically different in CD1 and CD2 sequences. Clinical prognosis-related genetic variations such as nucleotide mutation T1762/A1764 (27.93%), A2189C (12.85%), G1613A (8.94%), T1753C (8.38%), T53C (4.47%) T3098C (1.68%) and PreS deletion (2.23%) were detected in CD recombinants. (4) From the inner land of China to the northeast boundary of India, different geographical distributions between CD1 and CD2 were identified. (5) Twenty-seven (2.14%) HBsAg/HBsAb coexistence serum samples were identified. S protein amino acid mutation and PreS deletion were with significant differences between HBsAg/HBsAb coexistence group and control group.

Conclusions

HBV/CD may have a mixed China and South Asia origin. Based on genetic variations, the clinical prognosis of CD recombinant seems more temperate than genotype C strains in China. The HBsAg/HBsAb coexistence is a result of both PreS deletion and aa variation in S protein. Several unique mutations were frequently detected in HBV/CD isolates, which could potentially influence the clinical prognosis.

The role of hepatitis B surface antibodies in HBV infection, disease and clearance

The clinical sequelae associated with chronic HBV infection is generally regarded as a consequence of an inadequate and inappropriate immune response to active viral replication, predominantly at the T-cell level. However, recent studies on hepatitis B surface antigen (HBsAg)-specific B cells and hepatitis B surface antibody (anti-HB) responses have identified their previously unrecognized role in the pathogenesis of chronic hepatitis B (CHB). These studies have also uncovered novel therapeutic approaches to more effectively target HBsAg loss and seroconversion, an important end point and regarded as a functional cure. Anti-HBs IgG has also been shown to have multiple direct acting antiviral roles with the Fab component directly blocking viral entry, and release while the Fc component has been linked to antibody dependent cellular cytotoxicity. Likewise, the HBsAg-specific B-cell dysfunctionality can be reversed providing new therapeutic opportunities to achieve functional cure in CHB.

Polymorphism rs368234815 of interferon-λ4 gene and generation of antibodies to hepatitis B virus surface antigen in extracorporeal dialysis patients

Background: The rs368234815 polymorphism of interferon-λ4 (IFN-λ4) gene (IFNL4) is involved in HBV surface antigen (HBsAg) clearance in non-uremic subjects. The rs368234815 ΔG/ΔG genotype can express IFN-λ4 while the TT/TT genotype cannot. We investigated whether rs368234815 is associated with the development of HBsAg antibodies (anti-HBs) in response to vaccination or infection, and HBsAg loss after infection in uremic patients on extracorporeal dialysis.Research design and methods: Dialyzed patients (n = 467) were genotyped for rs368234815 by the polymerase chain reaction-restriction fragment length polymorphism method. Non-responders to HBV vaccination we compared with responders. HBsAg positive patients not able to develop anti-HBs we compared with individuals who eliminated HBsAg and generated anti-HBs. HBsAg positive patients we compared with subjects who eliminated HBsAg.Results: The ∆G allele was associated with the 1.6-fold higher risk not to develop anti-HBs titers ≥10 IU/L in response to HBV vaccination and infection (P = 0.016 adjusted for gender, age at dialysis onset, HCV RNA). The ∆G/∆G genotype indicated a higher probability of non-responsiveness to HBV vaccination than the TT/TT genotype (OR 2.64, 95%CI 1.01-6.87, adjusted P = 0.048).Conclusions: In extracorporeal dialysis patients, IFNL4 rs368234815 is associated with the capacity to produce protective anti-HBs titers in response to HBV vaccination.

Predicting HBsAg clearance in genotype A chronic hepatitis B using HBsAg epitope profiling: A biomarker for functional cure

BACKGROUND AND AIM

Functional cure is the major goal of chronic hepatitis B (CHB) therapy though few biomarkers predict this outcome. HBsAg epitope occupancy can be influenced by therapeutic and immune pressure. The aim of this study was to map the HBsAg epitope profiles during long-term nucleos(t)ide analogue therapy in patients with genotype A CHB, in the context of HBsAg loss (SL)/seroconversion.

METHODS

We evaluated 25 genotype A CHB patients in the GS-US-174-0103 trial of HBeAg-positive CHB patients treated with tenofovir or adefovir for 4 years, 14 who achieved SL whilst 11 had no change. We epitope mapped the major domains of HBsAg to identify those patients with HBsAg clearance profile (CP) (loss of binding at both loops 1 and 2 epitopes of the 'a' determinant) vs non-clearance profile (no change in epitope recognition, or loss of epitope binding at one loop only), correlating this to on-treatment HBsAg responses. Complexed anti-HBs was also measured.

RESULTS

Analysis of the HBsAg epitope profiles of the 25 patients at baseline identified no predictive correlation with SL. In contrast, analysis at week 48 and end of study (week 192) or prior to SL identified significant predictive associations between development of HBsAg CPs and outcome of functional cure. The detection of a CP also correlated with the development of an alanine aminotransferase flare and detection of anti-HBs complexed with HBsAg.

CONCLUSION

The detection of HBsAg CPs by epitope mapping represents a novel viral biomarker, reflecting an emerging anti-HBs selection pressure prior to functional cure.

Toward a Functional Cure for Hepatitis B: The Rationale and Challenges for Therapeutic Targeting of the B Cell Immune Response

The central role of the cellular immune response in the control and clearance of the hepatitis B virus (HBV) infection has been well-established. The contribution of humoral immunity, including B cell and antibody responses against HBV, has been investigated for a long time but has attracted increasing attention again in recent years. The anti-HBs antibody was first recognized as a marker of protective immunity after the acute resolution of the HBV infection (or vaccination) and is now defined as a biomarker for the functional cure of chronic hepatitis B (CHB). In this way, therapies targeting HBV-specific B cells and the induction of an anti-HBs antibody response are essential elements of a rational strategy to terminate chronic HBV infection. However, a high load of HBsAg in the blood, which has been proposed to induce antigen-specific immune tolerance, represents a major obstacle to curing CHB. Long-term antiviral treatment by nucleoside analogs, by targeting viral translation by siRNA, by inhibiting HBsAg release via nucleic acid polymers, or by neutralizing HBsAg via specific antibodies could potentially reduce the HBsAg load in CHB patients. A combined strategy including a reduction of the HBsAg load via the above treatments and the therapeutic targeting of B cells by vaccination may induce the appearance of anti-HBs antibodies and lead to a functional cure of CHB.

Coexistence of low levels of HBsAg and high levels of anti-HBs may increase risk of hepatocellular carcinoma in chronic hepatitis B patients with high HBV load

OBJECTIVE

The clinical significance of coexistence of HBsAg/anti-HBs in chronic hepatitis B (CHB) patients remains controversial. This study was aimed to assess the association of this serological pattern with hepatocellular carcinoma (HCC) in patients with CHB.

METHODS

In this cross-section study, 206 CHB patients with coexistence of HBsAg/anti-HBs and 206 CHB patients with HBsAg alone were included to evaluate the risk of HCC development by logistic regression analysis. In addition, a retrospective cohort of 260 patients with CHB was recruited to estimate the cumulative incidence of HCC by Kaplan-Meier analysis.

RESULTS

The serological pattern of coexistence of HBsAg/anti-HBs, with high levels of ("High") HBsAg/low levels of ("Low") anti-HBs, were considered as independent risk factors for HCC. In particular, patients with "High" HBsAg/"High" anti-HBs [odds ratio (OR), 4.295; 95% confidence interval (CI), 1.104-16.699; p = 0.035] and "Low" HBsAg/ "High" anti-HBs (OR, 3.207; 95%CI, 1.299-7.919; p = 0.012) exhibited significantly higher risk for HCC development. However, only "Low" HBsAg /"High" anti-HBs might increase risk of HCC in CHB patients with high HBV load (logrank p < 0.001) in our cohort study.

CONCLUSION

The coexistence of "Low" HBsAg /"High" anti-HBs might increase the risk of HCC development in CHB patients with high HBV load, which reflected that the long-term interaction between immune response and virus might lead to the development of HCC. The identification of the patients with poor prognosis will help clinicians to refine the therapeutic decisions and individualize follow-up strategies.

Down-regulation of hepatitis delta virus super-infection in the woodchuck model

Mechanisms mediating clearance of hepatitis delta virus (HDV) are poorly understood. This study analyzed in detail profound down-regulation of HDV infection in the woodchuck model. Super-infection with HDV of woodchucks chronically infected with HBV-related woodchuck hepatitis virus produced two patterns. In the first, HDV viremia had a sharp peak followed by a considerable decline, and initial rise of HDV virions' infectivity followed by abrupt infectivity loss. In the second, HDV titer rose and later displayed plateau-like profile with high HDV levels; and HDV infectivity became persistently high when HDV titer reached the plateau. The infectivity loss was not due to defects in the virions' envelope, binding to anti-envelope antibodies, or mutations in HDV genome, but it correlated with profound reduction of the replication capacity of virion-associated HDV genomes. Subsequent finding that in virions with reduced infectivity most HDV RNAs were not full-length genomes suggests possible HDV clearance via RNA fragmentation.

Vaccination Coverage and Awareness of Hepatitis B Virus Among Healthcare Students at a University in Cyprus

Introduction

The risk for healthcare students to get infected by transmitting infectious viruses, including hepatitis B virus (HBV), in a hospital setting is extremely high through exposure to blood and/or body secretions.

Aim

The aim of this work was to evaluate both the vaccination history of healthcare students at a University in Cyprus and their serologic immunity against HBV. In addition, we assessed their knowledge and behaviors towards the transmission and prevention of hepatitis B (HB).

Results

Total amount of 168 students participated in this study and more than 50% of them provided complete documentation of vaccination history against HBV. Antibodies levels ×10 mIU/mL to HB surface antigen (HBsAg) were detected for the 98.8% of healthcare students while 1.2% of the participants tested positive for HBsAg and antibodies to HB core antigen indicating chronic infection. Our study also revealed significant gaps in the knowledge of healthcare students on the efficiency of the vaccine against HBV and in terms of the HBV transmission.

Conclusions

More information needs to be provided to healthcare students in Cyprus regarding HBV transmission and vaccination. In addition, there is a need for intervention to provide a safer workplace environment.

Serum sphingolipid levels associate with upcoming virologic events and HBV genotype D in a cohort of patients with HBeAg-negative HBV infection

OBJECTIVES

Sphingolipids (SLs) have been implicated as potent regulators of the hepatitis B virus (HBV) life cycle. We investigated the SL biomarker potential regarding virologic endpoints in a prospective subgroup of patients with HBeAg-negative chronic HBV infection.

METHODS

From 2009-2016 98 patients with HBeAg-negative HBV infection were prospectively followed over four years. Clinical, laboratory and imaging data were evaluated annually. SLs were assessed in available serum probes via liquid chromatography coupled to tandem mass spectrometry.

RESULTS

Of those 98 patients, 10 (10.2%) showed HBV reactivation, 13 (13.2%) lost HBsAg and 9 (9.1%) gained status of HBsAg-/HBsAb-coexistence, whereas 66 (67.3%) had no events. Within the four-year analysis sphingosine (p = 0.020), sphinganine (p<0.001), dhS1P (p<0.001), C16DHC (p<0.01) and C20Cer (p<0.001) showed a significant upregulation in patients without virologic events, C18Cer significantly decreased (p<0.001). At baseline decreased S1P-, dhS1P- and C16Cer-levels were observed in patients with upcoming status of HBsAg-/HBsAb-coexistence. S1P and dhS1P levels were elevated HBV genotype D infected patients.

CONCLUSIONS

In a prospective cohort of patients with a HBeAg-negative HBV infection, serum SLs associated with the virologic course and HBV genotype D. Further studies are required to elucidate SLs as potential novel predictors of the course of HBeAg-negative HBV infection.

Identified OAS3 gene variants associated with coexistence of HBsAg and anti-HBs in chronic HBV infection

The underlying mechanism of coexistence of hepatitis B surface antigen (HBsAg) and hepatitis B surface antigen antibody (anti-HBs) is still controversial. To identify the host genetic factors related to this unusual clinical phenomenon, a two-stage study was conducted in the Chinese Han population. In the first stage, we performed a case-control (1:1) age- and gender-matched study of 101 cases with concurrent HBsAg and anti-HBs and 102 controls with negative HBsAg and positive anti-HBs using whole exome sequencing. In the second validation stage, we directly sequence the 16 exons on the OAS3 gene in two dependent cohorts of 48 cases and 200 controls. Although, in the first stage, a genome-wide association study of 58,563 polymorphism variants in 101 cases and 102 controls found no significant loci (P-value ≤ .05/58563), and neither locus achieved a conservative genome-wide significance threshold (P-value ≤ 5e-08), gene-based burden analysis showed that OAS3 gene rare variants were associated with the coexistence of HBsAg and anti-HBs. (P-value = 4.127e-06 ≤ 0.05/6994). A total of 16 rare variants were screened out from 21 cases and 3 controls. In the second validation stage, one case with a stop-gained rare variant was identified. Fisher's exact test of all 149 cases and 302 controls showed that the rare coding sequence mutations were more frequent in cases vs controls (P-value = 7.299e-09, OR = 17.27, 95% CI [5.01-58.72]). Protein-coding rare variations on the OAS3 gene are associated with the coexistence of HBsAg and anti-HBs in patients with chronic HBV infection in Chinese Han population.

Reactivation of a Vaccine Escape Hepatitis B Virus Mutant in a Cambodian Patient During Anti-Hepatitis C Virus Therapy

A 76-year-old Cambodian man co-infected with hepatitis B virus (HBV) and hepatitis C virus (HCV) 6c-1 presented for care. HBV DNA was intermittently detectable despite anti-HBs levels being above the protective threshold. During treatment for HCV, HBV DNA levels increased. Sequencing revealed multiple mutations including vaccine escape mutation and mutations predicted to enhance fitness. This case represents exacerbation of an HBV vaccine escape mutant during a direct-acting antiviral therapy.

Mutations within the major hydrophilic region (MHR) of Hepatitis B virus from individuals with simultaneous HBsAg and anti-HBs in Guangzhou, Southern China

The mechanism of the coexistence of HBsAg and anti-HBs is still unclear. This study investigated the variations located in the major hydrophilic region (MHR) of HBV from individuals with simultaneous HBsAg and anti-HBs in Guangzhou, southern China. Among 4455 samples analyzed, 179 (4.02%) patients were discovered with both HBsAg and anti-HBs. Finally, 44 individuals with concurrent HBsAg and anti-HBs (defined as group I), and 88 patients with positive HBsAg and negative anti-HBs (defined as group II, served as control) were enrolled in the study. The number of residue changes per 100 residues within the MHR in group I was 7.1 times more frequent than group II (P < 0.001) and was discovered mostly in the MHR1 (aa99-119) (P < 0.001). Two or more residue changes in the MHR were discovered in 15 patients (34.1%) of group I, but were found in only one (1.1%) patient of group II (P < 0.001). The most common variants in group I were at positions s101Q, s133M, s126T/I, s131T, s145G, s120P, and s129Q. In addition, sQ101 K, sT131N, and sM133L were more frequently discovered in group I with significant difference (P < 0.05). In chronic hepatitis B (CHB) patients, the simultaneous of HBsAg and anti-HBs were accompanied with an increase of MHR variants, and suggested that the HBsAg mutants were selected by naturally acquired anti-HBs during chronic carriage.

Hepatitis B Virus Blood Screening: Need for Reappraisal of Blood Safety Measures?

Over the past decades, the risk of HBV transfusion–transmission has been steadily reduced through the recruitment of volunteer donors, the selection of donors based on risk-behavior evaluation, the development of increasingly more sensitive hepatitis B antigen (HBsAg) assays, the use of hepatitis B core antibody (anti-HBc) screening in some low-endemic countries, and the recent implementation of HBV nucleic acid testing (NAT). Despite this accumulation of blood safety measures, the desirable zero risk goal has yet to be achieved. The residual risk of HBV transfusion–transmission appears associated with the preseroconversion window period and occult HBV infection characterized by the absence of detectable HBsAg and extremely low levels of HBV DNA. Infected donations tested false-negative with serology and/or NAT still persist and derived blood components were shown to transmit the virus, although rarely. Questions regarding the apparent redundancy of some safety measures prompted debates on how to reduce the cost of HBV blood screening. In particular, accumulating data strongly suggests that HBsAg testing may add little, if any HBV risk reduction value when HBV NAT and anti-HBc screening also apply. Absence or minimal acceptable infectious risk needs to be assessed before considering discontinuing HBsAg. Nevertheless, HBsAg remains essential in high-endemic settings where anti-HBc testing cannot be implemented without compromising blood availability. HBV screening strategy should be decided according to local epidemiology, estimate of the infectious risk, and resources.

Use of Current and New Endpoints in the Evaluation of Experimental Hepatitis B Therapeutics

New hepatitis B virus (HBV) therapies are expected to have breakthrough benefit for patients. HBV functional cure is sustained hepatitis B surface antigen loss and anti-HBs gain, with normalization of serum aminotransferases off therapy. Virologic or complete cure additionally includes loss of HBV covalently closed circular DNA. Currently available endpoints of therapy are inadequate to evaluate the efficacy of many of the new therapeutics. Therefore, either new ways of using the existing virologic endpoints and laboratory values or entirely new biomarkers are needed. In this review, we discuss the currently used endpoints, potential new endpoints, as well as what new markers are needed to assess the ability of HBV therapeutics to achieve functional and virologic cure in various phases of HBV infection. In addition, we discuss how patient selection from differing phases of HBV impacts the choice of HBV drug(s) needed to achieve cure.

Patients with Coexistence of Circulating Hepatitis B Surface Antigen and Its Antibody May Have a Strong Predisposition to Virus Reactivation During Immunosuppressive Therapy: A Hypothesis

Hepatitis B virus (HBV) reactivation is a well-recognized complication in patients who undergo immunosuppressive drug therapy. Although the recommendation of antiviral prophylaxis made by the American Gastroenterological Association in 2015 focuses on the risk stratification of different immunosuppressive drugs, risk factors for HBV reactivation are also worth identifying in clinical practice. Recent studies have shown that the uncommon serological pattern of coexistent circulating HBV surface antigen (HBsAg) and its antibody (anti-HBs) was associated with double mutations (A1762T/G1764A) in the basal core promoter (BCP) region of the HBV genome, which is critical for HBV replication. Here, we depicted rheumatoid arthritis (RA) patients with coexistent HBsAg and anti-HBs in our medical center, who developed HBV reactivation during immunosuppressive drug therapy. DNA sequencing analysis of the HBV genome revealed triple mutations (A1762T, G1764A, and T1753V) in the BCP region, which could further enhance the ability of HBV replication. Hence, a novel hypothesis is advanced for the first time that patients with coexistent HBsAg and anti-HBs may have a strong predisposition to HBV reactivation due to specific BCP mutations. This hypothesis would, if correct, justify the concurrent detection of HBsAg and anti-HBs in HBV screening in patients with rheumatic diseases and quickly recognize patients with high risk of HBV reactivation. Further controlled studies are needed to confirm this hypothesis.

Clinical patterns associated with the concurrent detection of anti-HBs and HBV DNA

Simultaneous detection of anti-HBs and HBV DNA is a rare serological combination and has been described in acute and chronic HBV infection. To scrutinize viral and clinical patterns associated with concurrent detection of anti-HBs and HBV DNA. Simultaneous detection of anti-HBs and HBV DNA was observed in 64/1444 (4.4%) patients treated for HBV infection at the University Hospital of Essen from 2006 to 2016 (8 with acute, 20 with reactivated, and 36 chronic HBV infection). Clinical data and laboratory parameters were analyzed. Regions of the small hepatitis B surface antigen (SHB) and the reverse transcriptase (RT) were sequenced using next generation sequencing (NGS). Among the 64 patients with detectable HBV DNA and anti-HBs, 17 were HBsAg negative (HBsAg[-]), and two had acute liver failure. Patients with acute HBV infection had fewer genotype specific amino acid substitutions in the SHB region than patients with reactivated HBV infection (4 [4.5] vs 9 [16.25], P = 0.043). However, we could observe a significantly higher number of mutations in the a-determinant region when comparing chronically infected patients to patients with acute infection (0 [1] vs 1 [1], P = 0.044). The ratio of nonsynonymous to synonymous mutations (Ka/Ks) was on average >1 for the SHB region and <1 for the RT region. The Ka/Ks ratio (>1) in the SHB region indicates that anti-HBs might have exerted selection pressure on the HBsAg. In three cases the diagnosis of acute HBV infection would have been at least delayed by only focusing on HBsAg testing.

Occult hepatitis B virus infection in HIV positive patients at a tertiary healthcare unit in eastern India

Occult HBV infection (OBI), defined by the presence of HBV DNA in absence of hepatitis B surface antigen (HBsAg), is a significant concern in the HIV-infected population. Of 441 HIV+/HBsAg- patients analyzed, the overall prevalence of OBI was 6.3% (28/441). OBI was identified in 21 anti-HBc positives (17.8%), as well as among those who lacked any HBV-specific serological markers (2.2%). Comparison with HIV/HBV co-infection revealed that the levels of CD4, ALT, and HBV DNA were significantly lower during occult infection. Discrete differences were also observed with respect to quasispecies divergence. Additionally, subgenotype D1 was most frequent in occult infection, while D2 was widespread during chronic infection. The majority (~90%) of occult D1 sequences had the sQ129R mutation in the surface gene. This study highlights several distinct features of OBI in India and underscores the need for additional HBV DNA screening in HIV-positive individuals.

Clinical features and viral quasispecies characteristics associated with infection by the hepatitis B virus G145R immune escape mutant

Coexistence of the hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (anti-HBs) is an uncommon phenomenon, and the underlying mechanisms remain largely unknown. Amino-acid (aa) substitution from glycine to arginine at aa 145 (G145R), in the major hydrophilic region, has been reported in patients with HBsAg and anti-HBs coexistence. However, there is limited knowledge about the clinical features and viral quasispecies characteristics associated with G145R mutant hepatitis B virus (HBV) infection. We herein describe the dynamic changes in the serological and virological markers in a case of hepatitis B with coexisting HBsAg and anti-HBs, caused by a G145R immune escape mutant (genotype C). Entecavir was administered during the 4th week after admission. Alanine aminotransferase peaked in the 16th week, while both the HBsAg and HBeAg declined rapidly. HBsAg clearance and hepatitis B e antigen (HBeAg)/hepatitis B e antibody (anti-HBe) seroconversion were achieved in the 36th week, and then entecavir was withdrawn. A follow-up of 96 weeks showed that HBV DNA remained undetectable and that anti-HBs was maintained above 100 mIU/mL. The quasispecies characteristics of the G145R mutant HBV were investigated via ultra-deep sequencing. The complexity and genetic distance of the S and RT regions were much higher in the 8th week than at baseline or in the 4th week. Moreover, the frequencies of mutations (L173P, Q181R and A184V) in cytotoxic T lymphocyte epitopes increased before entecavir treatment. These findings extend understanding of the evolution of HBV under host immune pressure and of the clinical outcomes of affected patients.

Novel and highly sensitive immunoassay for total hepatitis B surface antigen, including that complexed with hepatitis B surface antibody

BACKGROUND

Hepatitis B surface antigen (HBsAg) is used as a clinical marker of hepatitis B virus (HBV) infection. However, conventional HBsAg assays have so far failed to accurately detect HBsAg in blood because of interference by patient-derived antibodies against HBsAg (HBsAb).

METHODS

We developed a novel, fully automated assay system that can detect total HBsAg in blood, including antigens complexed with HBsAb. The immunoassay inactivates HBsAb via a simple pretreatment step to dissociate the HBsAg molecule from HBsAg-HBsAb complexes and thereby estimate total HBsAg. Accordingly, the test has been termed the "immunoassay for total antigen including complex via pretreatment (iTACT)-HBsAg."

RESULTS

The recovery rate of HBsAg in the presence of HBsAb was greater than 87 % at a cutoff value set at 5.0 mIU/mL on the basis of data from 545 healthy controls. Analyses using serial serum samples from 25 HBV carriers who became negative for HBsAg during follow-up showed that the iTACT-HBsAg could detect HBsAg over a period of years despite a loss in detection by conventional assays and was able to detect HBsAg in 39 (53 %) of 73 samples with HBsAb.

CONCLUSIONS

The new iTACT-HBsAg assay appears to detect total HBsAg with high sensitivity, even in the presence of HBsAb, and may useful in identifying subclinical or occult HBV carriers.

Mutation in the S gene a determinant of the hepatitis B virus associated with concomitant HBsAg and anti-HBs in a population in Northeastern Brazil

Mutations in the a determinant of S gene may develop co-existence of hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) in the serum of infected hepatitis B virus (HBV) individuals. Mutations in this region may change the antigenicity of HBsAg, which in turn, lead to escape of neutralizing action of anti-HBs antibodies. This study identified individuals with concomitant HBsAg and anti-HBs serological markers in individuals of Maranhão, Northeastern Brazil. Samples from a population-based study were evaluated for HBsAg, anti-HBs, and anti-HBc, and those that tested positive for simultaneous HBsAg and anti-HBs were submitted to HBV DNA quantification and S gene characterization by Sanger sequencing. Mutations were investigated in the a determinant located in major hydrophilic region (MHR) of the S gene. Among 3,984 samples analyzed, 92 (2.3%) were positive for HBsAg and three had the atypical HBsAg and anti-HBs-positive profile (3.26%). The frequency of HBsAg and anti-HBs co-existence was similar to previous studies. Only one individual harbored mutation in the S gene a determinant associated with this profile. Little is known about this phenomenon; however, studies as ours may contribute for future enlightenment of this important issue. J. Med. Virol. 89:458-462, 2017. © 2016 Wiley Periodicals, Inc.

Prevalence of hepatitis B and C markers in a population of an urban university in Rio de Janeiro, Brazil: a cross-sectional study

BACKGROUND AND RATIONALE

Epidemics of hepatitis B and C are a public health burden, and their prevalence in Brazil varies among regions. We determined the prevalence of hepatitis markers in an urban university population in order to support the development of a comprehensive program for HBV immunization and HBV/HCV diagnosis. Students, employees, and visitors (n = 2,936, 31 years IQR 24.5-50, female = 69.0% and 81.1% with at least 12 years of education) were enrolled from May to November 2013. Antibodies against hepatitis B surface antigen (anti-HBs), against hepatitis B core antigen (anti-HBc), and hepatitis B surface antigen (HBsAg) were detected with enzyme immunoassays and anti-hepatitis C virus (anti-HCV) antibodies with a chemiluminescence immunoassay. The results were confirmed with polymerase chain reaction for HCV and nucleic acid amplification test for hepatitis B virus (HBV).

RESULTS

The overall prevalence of markers among the participants was 0.136% (95% confidence interval [CI]: 0.003-0.270) for HBsAg, 6.44% (95% CI: 5.55-7.33%) for anti-HBc, 50.8% (95% CI: 48.9-52.7%) for anti-HBs > 10 mIU/mL, and 0.44% (95% CI: 0.20-0.68) for anti-HCV. Almost 30.4% had anti-HBs titers > 100 mIU/mL. Participants with a detectable HCV viral load (n = 9) were infected with genotype 1a.

CONCLUSIONS

In an urban university population, in which 80% of participants had > 11 years of education, prevalence increased with age, and self-declared ethnicity for anti-HBc and with age, marital status and professional activity for anti-HCV antibodies. A periodical offer of HCV rapid testing should be implemented, and HBsAg rapid testing should be offered to individuals above 20 years of age.

Hepatitis B surface antigen seroclearance during nucleoside analogue therapy: surface antigen kinetics, outcomes, and durability

BACKGROUND

Hepatitis B surface antigen (HBsAg) seroclearance is the recommended treatment end point for nucleoside analogue (NA) therapy in chronic hepatitis B, yet the underlying kinetics and durability of HBsAg seroclearance in NA-treated patients have not been well described.

METHODS

We compared the HBsAg kinetics and long-term serologic outcomes of 51 chronic hepatitis B patients achieving HBsAg seroclearance during NA therapy with those of 51 HBsAg-positive controls, matched for age, sex, hepatitis B e antigen status, NA type, and treatment duration. Viral profiles before and after HBsAg seroclearance during and after NA treatment cessation were determined.

RESULTS

The median time to HBsAg seroclearance and the median follow-up duration after HBsAg seroclearance were 61.2 and 51.6 months respectively. Patients achieving HBsAg seroclearance maintained high median rates of HBsAg reduction throughout therapy (first 6 months, 0.40 IU/mL/year; after year 1, 0.39 IU/mL/year; p = 0.809). For controls, the median rate of HBsAg reduction was significantly slower with time (first 6 months and after year 1, 0.19 and 0.05 IU/mL/year; p = 0.006). The difference in the median HBsAg reduction rates after year 1 between the two groups was significant (p < 0.001). The cumulative rates of antibody to HBsAg development and HBsAg seroreversion 72 months after HBsAg seroclearance were 68.9 and 8.3% (one patient receiving immunosuppressive therapy; one patient with pre-S/S variant), respectively. Among 22 patients who discontinued therapy after HBsAg seroclearance, 21 remained HBsAg negative with undetectable hepatitis B virus DNA and one patient with reactivation had the pre-S/S variant.

CONCLUSION

NA-treated patients achieving HBsAg seroclearance uniquely maintained high rates of HBsAg reduction throughout treatment, with HBsAg seroclearance durable in most of the patients after treatment cessation.

Status of hepatitis B infection - a decade after hepatitis B vaccination of susceptible Nicobarese, an indigenous tribe of Andaman & Nicobar (A&N) islands with high hepatitis B endemicity

BACKGROUND & OBJECTIVES

Andaman and Nicobar Islands of India, home to six primitive tribes, constituting about 10 per cent of the total population of these Islands have been detected with high endemicity of hepatitis B infection. During 2000, a total of 936 individuals ≤ 45 yr, negative for hepatitis B surface antigen (HBsAg) and antibody anti-HBs were vaccinated with three doses of a recombinant DNA hepatitis B vaccine in two villages of Car Nicobar Islands. The present study was undertaken to evaluate the impact of the hepatitis B vaccination with respect to the persistence of antibodies and incidence of new infections, prevalence of surface gene mutations among the Nicobarese community in the two villages ten years after hepatitis B vaccination.

METHODS

Follow up samples were collected from 211 individuals who had received three doses of vaccine ten years back and from a control group of 515 non-vaccinated individuals. The HBsAg, anti-HBs and anti-HBc assay results were compared among vaccinated and non-vaccinated groups. HBV DNA was extracted and sequenced from all the samples for detection of mutation. Genotyping and serotyping of the viruses were performed.

RESULTS

The results showed that 85.3 per cent of the vaccinated persons retained protective level of antibodies and among the non-vaccinated individuals, 54.2 per cent showed presence of anti-HBs indicating an exposure to the infection. The overall HBsAg positivity among the studies Nicobarese individuals was reduced to 7.4 per cent after 10 years of vaccination. Anti-HBc was positive in 60.6 and 57 per cent among the vaccinated and non-vaccinated individuals, respectively. Overall breakthrough infection of 8.5 per cent was detected among the vaccinated individuals. The predominant genotype and serotype circulating among these tribal populations were D and ayw3, respectively.

INTERPRETATION & CONCLUSIONS

The results of this study showed an overall reduction in the pool of HBsAg carriers because of the vaccination which helped in reducing the HBsAg carrier rate among the non-vaccinated also, probably due to an increase in herd immunity and reduction in the source of infection. Further studies need to be done to evaluate long term benefits of hepatitis B vaccination among these tribes.

Genetic variation of occult hepatitis B virus infection

Occult hepatitis B virus infection (OBI), characterized as the persistence of hepatitis B virus (HBV) surface antigen (HBsAg) seronegativity and low viral load in blood or liver, is a special form of HBV infection. OBI may be related mainly to mutations in the HBV genome, although the underlying mechanism of it remains to be clarified. Mutations especially within the immunodominant “α” determinant of S protein are “hot spots” that could contribute to the occurrence of OBI via affecting antigenicity and immunogenicity of HBsAg or replication and secretion of virion. Clinical reports account for a large proportion of previous studies on OBI, while functional analyses, especially those based on full-length HBV genome, are rare.

Epidemiological characteristics of the carriers with coexistence of HBsAg and anti-HBs based on a community cohort study

The coexistence of HBsAg and anti-HBs is an atypical serological pattern in HBV infection. There is no epidemiological characteristics of this serological pattern in the community and there is controversy over the molecular mechanisms underlying this pattern. We investigated the epidemiological characteristics of the carriers with HBsAg and anti-HBs in a longitudinal community cohort study. The prevalence of this atypical serological pattern was 2.93% (122/4169) in HBsAg-positive populations. The prevalence progressively increased with age from 40 to 70 years old. The rate of HBeAg positive and detectable HBV DNA were both significantly higher in carriers with this pattern than in carriers who were HBsAg positive but anti-HBs negative (26/122 verse 598/4047, P = 0.046; 86/122 verse 275/529,P < 0.001). After 1 year of follow-up, 85.19% of the carriers still had coexistence HBsAg and anti-HBs, 14.81% of the carriers lost their anti-HBs. Viral sequencing showed that carriers with coexistence of HBsAg and anti-HBs had higher numbers of residue changes within the S gene than carriers who were HBsAg positive but anti-HBs negative (2.42 verse 1.33 changes per 100 residues, P < 0.05). Hence, the coexistence of HBsAg and anti-HBs is a unique serological pattern which may be associated with an increased risk of adverse clinical outcome and may be related to HBsAg immune variants which have genotypic heterogeneity.

Genetic variation of hepatitis B virus and its significance for pathogenesis

Hepatitis B virus (HBV) has a worldwide distribution and is endemic in many populations. Due to its unique life cycle which requires an error-prone reverse transcriptase for replication, it constantly evolves, resulting in tremendous genetic variation in the form of genotypes, sub-genotypes, and mutations. In recent years, there has been considerable research on the relationship between HBV genetic variation and HBV-related pathogenesis, which has profound implications in the natural history of HBV infection, viral detection, immune prevention, drug treatment and prognosis. In this review, we attempted to provide a brief account of the influence of HBV genotype on the pathogenesis of HBV infection and summarize our current knowledge on the effects of HBV mutations in different regions on HBV-associated pathogenesis, with an emphasis on mutations in the preS/S proteins in immune evasion, occult HBV infection and hepatocellular carcinoma (HCC), mutations in polymerase in relation to drug resistance, mutations in HBV core and e antigen in immune evasion, chronicalization of infection and hepatitis B-related acute-on-chronic liver failure, and finally mutations in HBV x proteins in HCC.

Mutations in the S gene and in the overlapping reverse transcriptase region in chronic hepatitis B Chinese patients with coexistence of HBsAg and anti-HBs

Background

The mechanism underlying the coexistence of hepatitis B surface antigen and antibodies to HBsAg in chronic hepatitis B patients remains unknown.

Aims

This research aimed to determine the clinical and virological features of the rare pattern.

Methods

A total of 32 chronic hepatitis B patients infected by HBV genotype C were included: 15 carrying both HBsAg and anti-HBs (group I) and 17 solely positive for HBsAg (group II). S gene and reverse transcriptase region sequences were amplified, sequenced and compared with the reference sequences.

Results

The amino acid variability within major hydrophilic region, especially the “a” determinant region, and within reverse transcriptase for regions overlapping the major hydrophilic region in group I is significantly higher than those in group II. Mutation sI126S/T within the “a” determinant was the most frequent change, and only patients from group I had the sQ129R, sG130N, sF134I, sG145R amino acid changes, which are known to alter immunogenicity.

Conclusions

In chronic patients, the concurrent HBsAg/anti-HBs serological profile is associated with an increased aa variability in several key areas of HBV genome. Additional research on these genetic mutants are needed to clarify their biological significance for viral persistence.

Sequence analysis of the HBV S protein in Chinese patients with coexisting HBsAg and anti-HBs antibodies

The coexistence of hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) in patients with hepatitis B virus (HBV) infection has been discovered and explained for several decades, but debate still exists. This study was to explore the relationship between this special serological pattern and mutations in S gene region. Fifteen patients with coexisting HBsAg and anti-HBs were selected as the experimental group, and 27 patients with HBsAg positive only were selected as the control group. The S gene region was amplified and sequenced. No significant differences were observed between the two groups with regard to age, gender, alanine aminotransferase level, HBsAg titer, genotype, and HBV DNA level. The patients from the two groups were infected with HBV of the genotype B and C. Compared with the control group, the experimental group showed a higher variability in amino acid within the N-terminal region and the MHR, especially the "a" determinant. The most frequent change in patients from the experimental group was located at positions s126. The coexistence of HBsAg and anti-HBs might be associated with the increased amino acid mutations in the "a" determinant. Further studies should be performed to determine the clinical implication of this serological pattern, including the binding of anti-HBs to HBsAg, escape from immune system, and efficacy of antiviral therapy.