High prevalence of occult hepatitis B virus infection in children born to HBsAg-positive mothers despite prophylaxis with hepatitis B vaccination and HBIG

Occult hepatitis B infection in children born to HBeAg-positive women confers a low long-term risk for HBsAg-positive infection

PURPOSE

Mother-to-child transmission (MTCT) has been the main cause of chronic hepatitis B virus (HBV) infection, particularly in East Asia. Hepatitis B immunoglobulin (HBIG) and vaccination given directly after birth effectively prevents hepatitis B surface antigen (HBsAg)-positive (overt) HBV infection, but occult hepatitis B infection (OBI) may develop despite adequate prophylaxis. The aim of this study was to investigate the long-term outcome in children born to mothers with very high HBV DNA levels with special focus on children discovered in early childhood with OBI.

METHODS

One-year and long-term outcome regarding overt and occult HBV infection were analysed in 66 children born to hepatitis B e antigen (HBeAg)-positive mothers, and were compared with one-year outcome in 69 children born to HBeAg-negative mothers. The children were born between 1998 and 2018.

RESULTS

Six children born to HBeAg-positive mothers developed overt chronic HBV infection, in two cases after normal pregnancies and despite HBIG and vaccination, but never when nucleotide analogue treatment was given during pregnancy. OBI with HBV DNA detected in serum in the absence of surface antigen (HBsAg) was observed in four children at the age of 1 year. One of them was transiently HBsAg-positive at the age of 7 years. At long-term follow-up, six children had overt chronic infection, one had OBI and six had previous OBI or positive anti-HBc suggesting resolved unidentified infections.

CONCLUSION

The results indicate that children born to mothers with high HBV DNA levels have approximately 10% risk to develop OBI despite antiviral treatment, vaccination and HBIG, but that such OBI confers a minimal long-term risk for overt infection, at least in immunocompetent children.

An overview of occult hepatitis B infection (OBI) with emphasis on HBV vaccination

Background

The prevalence of chronic hepatitis B virus (HBV) poses a significant threat to the lives of 257 million individuals globally, potentially resulting in severe outcomes such as liver cirrhosis or hepatocellular carcinoma. Among the existing preventive measures, yeast-derived vaccines have proven to be the most efficacious approach in combatting hepatitis B. Nonetheless, as scientific inquiries focus more on occult HBV infection (OBI) in vaccinated persons and the lingering risk of vertical transmission affecting 10-30 % of babies born to HBsAg-positive mothers, there is a growing apprehension regarding the inability of HBV vaccines to ensure complete immunity. This study aims to offer a more comprehensive understanding of the implications of widespread HBV vaccination initiatives on OBI while tackling the primary limitations associated with current vaccine formulations.

Methods

The exploration was conducted on PubMed, Scopus, and Web of Science databases to pinpoint research on OBI within vaccinated cohorts. A sum of 76 suitable studies was recognized.

Discussion

Multiple studies have documented the occurrence of OBI in fully vaccinated individuals, including both the general population and high-risk groups, such as newborns born to HBsAg-positive mothers. Factors contributing to vaccine failures include low-level anti-HBs antibodies, high maternal viral loads in mother-to-child transmission cases, as well as the presence of vaccine escape mutants and heterologous HBV genotypes. However, further research is needed to precisely understand the impact of active immunization on the emergence of OBI in vaccinated populations. Nonetheless, it is apparent that the advancement of more effective HBV vaccines could potentially lead to the extinction of HBV.

Hepatitis B virus in oocytes and embryos: pregnancy outcomes and children's health

Objective

To investigate whether the presence of hepatitis B virus (HBV) in oocytes and embryos affects pregnancy outcomes for in vitro fertilization and embryo transfer (ET) as well as is related to the vertical transmission of HBV to children.

Design

Retrospective cohort study.

Setting

A university-affiliated fertility center.

Patients

This study included 167 couples with at least 1 hepatitis B surface antigen-seropositive partner. These couples underwent in vitro fertilization-ET, and the discarded oocytes and embryos had been tested for HBV. Couples with HBV-positive oocytes or embryos were categorized as the positive group, whereas those couples with HBV-negative oocytes and embryos served as the negative group.

Interventions

None.

Main Outcome Measures

Pregnancy outcomes and the rate of children's HBV infection.

Results

The pregnancy outcomes of fresh and frozen ETs were not associated with the presence of HBV in the oocytes and embryos. Of the 106 infants born, 1 child whose mother tested positive for hepatitis B surface antigen but had negative oocytes and embryos was infected with HBV. Additionally, 26.09% of children who had been administered passive immunization and active vaccinations did not reach protective levels of anti-HBV antibodies (hepatitis B surface antibodies) and became nonresponders. The negative rate of children's hepatitis B surface antibody was associated with the presence of HBV in oocytes and embryos (odds ratio, 3.01; 95% confidence interval, 1.04-9.25).

Conclusions

The presence of HBV in oocytes and embryos did not affect pregnancy outcomes or result in the vertical transmission of HBV to the offspring of HBV carriers. Follow-up is needed for HBV-vaccinated children with an HBV-infected parent. Booster vaccinations are necessary for continued protection.

The Characteristic of HBV Quasispecies Is Related to Occult HBV Infection of Infants Born to Highly Viremic Mothers

Although a combination of immunoprophylaxis and antiviral therapy can effectively prevent mother-to-child transmission (MTCT) of hepatitis B virus (HBV), a considerable number of infants born to highly viremic mothers still develop occult HBV infection (OBI). To uncover the virological factor and risk predictor for OBI in infants, we found that the diversity and complexity of maternal HBV quasispecies in the case group were lower than those in the control group. Mutations with significant differences between the two groups were most enriched in the NTCPbd and PreC regions. Genetic distance at the amino-acid level of the PreC region, especially the combination of three amino-acid mutations in the PreC region, could strongly predict the risk of OBI in infants. HBV quasispecies in OBI infants were highly complex, and the non-synonymous substitutions were mainly found in the RT and HBsAg regions. The sK47E (rtQ55R) and sP49L mutations in OBI infants might contribute to OBI through inhibiting the production of HBV DNA and HBsAg, respectively. This study found the potential virological factors and risk predictors for OBI in infants born to highly viremic mothers, which might be helpful for controlling OBI in infants.

The seroepidemiology of isolated core antibody against hepatitis B among Taiwanese adults - A large hospital-based study

BACKGROUND/PURPOSE

This study aims to investigate the prevalence of isolated core antibodies against hepatitis B (IAHBc) in different birth cohorts using a large medical record database.

METHODS

Hepatitis B viral serological test data were collected from a chart cloud database at a medical center in Taiwan between January 2006 and December 2018. The data collected included birth year, sex, hepatitis B viral markers (HBsAg, anti-HBs or anti-HBc), and hepatitis B vaccination records. Enrolled patients were grouped according to their birth year into three categories: ≤ 1986, 1987-1992, and ≥ 1993, which correspond to no neonatal hepatitis B immunization, plasma-derived HB vaccine (PDHBV), and recombinant hepatitis B vaccine (RHBV), respectively. Prevalence of hepatitis B viral seromarkers, including IAHBc, was calculated by sex, age groups, and birth cohorts. Those who underwent repeated hepatitis B serology tests were included for further analysis to follow up their serostatus.

RESULTS

A total of 117,335 adults with complete hepatitis B serologic data were analyzed. Among them, 6641 individuals (5.7 %) were found to have IAHBc. The prevalence of IAHBc was 11.4 %, 0.8 %, and 0.3 % among those born before 1986, between 1987 and 1992, and after 1992, respectively. Among the 690 subjects with repeated blood tests and complete hepatitis B serologic data, 551 cases (79.9 %) remained IAHBc. The other cases included resolved infection status (13.9 %), seronegativity for three HB seromarkers (3 %), and carrier of hepatitis B virus (2.3 %).

CONCLUSION

The management of individuals with IAHBc should be tailored to their age, vaccination status, and risk factors for occult hepatitis B viral infection.

Cytokine IL-5 and HGF: combined prediction of non-/low immune response to hepatitis B vaccination at birth in infants born to HBsAg-positive mothers

Background

The immune response to hepatitis B vaccine may be influenced by numerous factors, and patients with non/low response re-exposed to hepatitis B virus remain susceptible. Thus, a better understanding of the underlying mechanisms of non/low immune response in infants born to Hepatitis B surface antigen (HBsAg)-positive mothers is essential.

Methods

100 infants born to HBsAg-positive mothers from 2015 to 2020 were enrolled in the study, further divided into the non/low response group (n=13) and the moderate strong response group (n=87) based on the quantification of hepatitis B surface antibody at 12 months of age. The differential expression of 48 immune-related cytokines in the two groups was compared and analyzed in detail. The key cytokines were further identified and clinically predictive models were developed.

Results

We found that 13 cytokines were lowly expressed and one cytokine was highly expressed in the non/low response group, compared with the moderate strong response group at birth. In addition, 9 cytokines were lowly expressed and one cytokine was highly expressed in the non/low response group at 12 months of age. Furthermore, we found that IL-5 and HGF were promising predictors for predicting the immunization response to hepatitis B vaccine in infants, and the combination of the two cytokines showed the best predictive efficiency, with an area under the curve (AUC) value of 0.844.

Conclusion

The present study provides a theoretical basis on cytokines for developing and implementing effective immunotherapies against non/low immune response in infants born to HBsAg-positive mothers.

Global prevalence of occult HBV infection in children and adolescents: A systematic review and meta-analysis

INTRODUCTION AND OBJECTIVES

Occult HBV infection (OBI) is a specific form of hepatitis B virus (HBV) infection and has the possibility of developing into hepatocellular carcinoma (HCC) in adults. This study aimed to estimate the global prevalence of occult HBV infection in children and adolescents.

MATERIALS AND METHODS

We systematically searched PubMed, Embase, Web of Science, and Cochrane databases for relevant studies on the prevalence of OBI in children and adolescents. Meta-analysis was performed using STATA 16 software.

RESULTS

Fifty studies were included. The overall prevalence of OBI in children and adolescents was 7.5% (95% CI: 0.050-0.103). In different risk populations, OBI prevalence was remarkably high in the HIV-infected population (24.2%, 95% CI: 0.000-0.788). The OBI prevalence was 0.8% (95% CI:0.000-0.029) in the healthy population, 3.8% (95% CI:0.012-0.074) in the general population, and 6.4% (95% CI: 0.021-0.124) in children born to HBsAg-positive mothers. Based on different serological profiles, the prevalence of OBI in HBsAg-negative and anti-HBc-positive patients was 6.6% (95% CI: 0.016-0.136), 3.0% (95% CI: 0.009-0.059) in HBsAg-negative and anti-HBc-negative patients, 4.6% (95% CI: 0.015-0.088) in HBsAg-negative and anti-HBs-positive patients, and 3.7% (95% CI: 0.001-0.102) in HBsAg-negative and anti-HBs-negative patients.

CONCLUSIONS

Despite HBV vaccination and hepatitis B immunoglobulin (HBIG), OBI is common in children and adolescents in high-risk groups.

Protective Effect of Neonatal Hepatitis B Vaccine Against HBV Breakthrough Infection in Children with Leukemia: A Real-world Study

BACKGROUND AND AIMS

Hepatitis B vaccine is the most effective preventive measure against hepatitis B virus (HBV) infection. However, the risk of HBV breakthrough infection in fully immunized children (neonatal hepatitis B immunization) who receive immunosuppressive therapy and transfusion of blood components is not well characterized. In this real-world study, we aimed to investigate the immune protection conferred by neonatal hepatitis B vaccine in children with acute lymphoblastic leukemia (ALL) who were treated with immunosuppressive therapy and blood component transfusions.

METHODS

Children with ALL who had received all three doses of neonatal hepatitis B vaccine were included in this study. HBV seromarkers were detected before and after the initiation of immunosuppressive therapy.

RESULTS

A total of 1,011 children with ALL who were fully vaccinated against hepatitis B in infancy before the initiation of immunosuppressive therapy were eligible for inclusion. HBV infection was detected in four of 410 children (0.98%) with an HBsAg test after the initiation of immunosuppressive therapy. The median interval from treatment initiation was 19 months.

CONCLUSIONS

Three doses of neonatal hepatitis B vaccine conferred adequate protection. In endemic regions, there is a low risk of HBV breakthrough infection in fully immunized children with immunosuppressive therapy.

Screening of Occult Hepatitis B and C Virus Infection in Working Children, Tehran, Iran

Background: Working children are susceptible to infection with various infectious microorganisms. Unfortunately, the difficulties of working children are growing at a remarkable speed worldwide. Objectives: The aim of this research was to determine the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, as well as to evaluate the level of anemia, calcium, and phosphorus in working children. Methods: This cross-sectional research was performed on 370 Iranian and Afghan working children from February 2018 to May 2019. Hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb), hepatitis B core antibody (HBcAb), and anti-HCV Ab were evaluated using an enzyme-linked immunosorbent assay (ELISA). Furthermore, HCV-RNA and genomic HBV-DNA in the plasma and peripheral blood mononuclear cell (PBMC) specimens of the participants were investigated. The restriction fragment length polymorphism (RFLP) method was used to determine the genotype of HCV, and sequencing was performed to confirm. Results: The mean age of the participants was 10.1 ± 2.1 years (range, 6 - 15 years), and 229 (61.9%) were male. None of the studied children had any detectable HBV-DNA in the plasma and PBMC. The HCV genome was not detected in the plasma of the children, but HCV-RNA was assessed in the PBMC sample of 1 child (0.3%). Therefore, one of the children had occult HCV infection (OCI). The genotype of HCV in this child was subtype 1a. Furthermore, HBsAb was detected in Iranian (41.5%) and Afghan children (40.0%), and 2 (0.54%) of the working children were HBsAg positive. In 3 participants (0.8%), a positive HBcAb test result was noted. Conclusions: The prevalence of HCV and HBV infection in working children in Iran is extremely rare. However, there is a possibility of the presence of OCI in these children.

Prevalence of occult hepatitis B virus infection in adults: a systematic review and meta-analysis

Background

Despite growing concerns about transmissibility and clinical impact, occult hepatitis B virus (HBV) infection has received little attention in the hepatitis elimination agenda. We aimed to estimate the prevalence of occult HBV infection at a global and regional scale and in specific populations.

Methods

For this systematic review and meta-analysis, we searched the MEDLINE, Embase, Global Health, and Web of Science databases for articles published in any language between Jan 1, 2010, and Aug 14, 2019. We included original articles and conference abstracts of any study design that reported the proportion of HBsAg-negative adults (aged ≥18 years) who are positive for HBV DNA (ie, people with occult HBV infection). The prevalence of occult HBV infection was pooled, using the DerSimonian-Laird random-effects model, in the general population and specific groups defined by the type of study participants (blood donors; other low-risk populations; high-risk populations; and people with advanced chronic liver disease), and stratified by HBV endemicity in each country. We also assessed the performance of anti-HBc as an alternative biomarker to detect occult HBV infection. The study was registered with PROSPERO, CRD42019115490.

Findings

305 of 3962 articles were eligible, allowing a meta-analysis of 140 521 993 individuals tested for HBV DNA. Overall, only two studies evaluated occult HBV infection in the general population, precluding unbiased global and regional estimates of occult HBV infection prevalence. In blood donors, occult HBV infection prevalence mirrored HBV endemicity: 0·06% (95% CI 0·00–0·26) in low-endemicity countries, 0·12% (0·04–0·23) in intermediate-endemicity countries, and 0·98% (0·44–1·72), in high-endemicity countries (p=0·0012). In high-risk groups, occult HBV infection prevalence was substantial, irrespective of endemicity: 5·5% (95% CI 2·9–8·7) in low-endemicity countries, 5·2% (2·5–8·6) in intermediate-endemicity countries, and 12·0% (3·4–24·7) in high-endemicity countries. The pooled sensitivity of anti-HBc to identify occult HBV infection was 77% (95% CI 62–88) and its specificity was 76% (68–83).

Interpretation

A substantial proportion of people carry occult HBV infection, especially among high-risk groups across the globe and people living in highly endemic countries. Occult HBV infection should be part of the global viral hepatitis elimination strategy.

Funding

None.

Establishment of monoclonal antibodies broadly neutralize infection of hepatitis B virus

Antibodies against hepatitis B virus S protein can protect against hepatitis B virus (HBV) infection. Therefore, hepatitis B immunoglobulin (HBIG), which contains HBsAb, is used clinically as a therapy for HBV infection. In this study, we obtained a series of monoclonal antibodies that recognize multiple HBV genotypes. All the antibodies recognized conformational epitopes of S protein, but not linear epitopes. Several antibodies neutralized HBV infection and exhibited strong affinities and neutralizing activities. Antigenic epitope analysis demonstrated that they recognized residue Ile152 of S protein_, which is localized outside the "a" determinant. Ile152 is highly conserved, and a mutation in this residue resulted in reduced expression of large hepatitis B surface proteins (L protein), suggesting that the amino acid at this position is involved in the expression of L protein. In addition, the antibodies neutralized the infection of hepatitis D virus possessing a Gly145 mutation to Arg in S protein, which is a well-known escape mutation against HBIG treatment. Using mouse monoclonal antibodies, we successfully established a humanized antibody possessing affinities and neutralizing activities similar to those of the original mouse antibody. The antibodies generated in this study may have potential for use in alternative antibody therapies for HBV infection. This article is protected by copyright. All rights reserved.

Epitope-Paratope Interaction of a Neutralizing Human Anti-Hepatitis B Virus PreS1 Antibody That Recognizes the Receptor-Binding Motif

Hepatitis B virus (HBV) is a global health burden that causes acute and chronic hepatitis. To develop an HBV-neutralizing antibody that effectively prevents HBV infection, we previously generated a human anti-preS1 monoclonal antibody (1A8) that binds to genotypes A–D and validated its HBV-neutralizing activity in vitro. In the present study, we aimed to determine the fine epitope and paratope of 1A8 to understand the mechanism of HBV neutralization. We performed alanine-scanning mutagenesis on the preS1 (aa 19–34, genotype C) and the heavy (HCDR) and light (LCDR) chain complementarity-determining regions. The 1A8 recognized the three residues (Leu22, Gly23, and Phe25) within the highly conserved receptor-binding motif (NPLGFFP) of the preS1, while four CDR residues of 1A8 were critical in antigen binding. Structural analysis of the epitope–paratope interaction by molecular modeling revealed that Leu100 in the HCDR3, Ala50 in the HCDR2, and Tyr96 in the LCDR3 closely interacted with Leu22, Gly23, and Phe25 of the preS1. Additionally, we found that 1A8 also binds to the receptor-binding motif (NPLGFLP) of infrequently occurring HBV. The results suggest that 1A8 may broadly and effectively block HBV entry and thus have potential as a promising candidate for the prevention and treatment of HBV infection.

Reduction of the occurrence of occult HBV infection in infants by increasing the dose of hepatitis B vaccine: a large prospective cohort study

Occult hepatitis B virus (HBV) infection (OBI) has been observed among infants born to hepatitis B surface antigen (HBsAg)-positive mothers despite successful immunoprophylaxis. This study enrolled 549 infants [349 infants received a 10μg/dose of hepatitis B vaccine (HepB), and 200 infants received 20μg/dose HepB] born to HBsAg-positive mothers with HBV DNA load >6log₁₀IU/mL. The anti-HBs levels in the 10μg group were significantly lower than that in the 20μg group both at 7 [652.48 (564.05-754.82) vs. 1541.72 (1268.69-1873.51) mIU/mL, P<0.001] and 12 months old [257.44 (220.29-300.88) vs. 1073.41 (839.27-1372.78) mIU/mL, P<0.001]. The OBI incidence in the 10μg group was significantly higher than that in the 20μg group at both 7 [21.55% (25/116) vs. 7.56% (9/119), P=0.002] and 12 months old [17.07% (14/82) vs. 6.90% (6/87), P=0.041]. OBI incidence in infants with anti-HBs levels <100mIU/mL was higher than that of those with anti-HBs ≥100mIU/mL [35.71% (5/14) vs. 13.12% (29/221), P=0.036]. This study showed that increasing the immunisation dose from 10μg to 20μg significantly improved anti-HBs levels and decreased OBI incidence in infants with a high maternal viral load. We recommend 20μg HepB to treat this high-risk population.

Neonatal hepatitis B vaccination protects mature adults from occult virus infection

BACKGROUND

Among elder children/young adults who received hepatitis B virus (HBV) vaccination during infancy, the serological status of HBsAg-negative and anti-HBc-positive [HBsAg(-)/anti-HBc(+)] was frequently reported, indicating potential occult HBV infection (OBI). It is required to define the long-term protection of neonatal vaccination against OBI in their mature adulthood.

METHODS

Building upon the 1983-1990 established Qidong Hepatitis B Intervention Study, we sampled 10% of the 28-35-year-old participants, who remained in the cohort by 2012. Each participant was tested for serological markers of HBsAg, anti-HBs, HBeAg, anti-HBe and anti-HBc. HBV-DNA and relaxed circular DNA (rcDNA) were determined in some HBsAg(-)/anti-HBc(+) individuals.

RESULTS

Totally, 3615 individuals from the neonatal vaccination group and 3100 individuals from the control group donated blood samples, respectively. In the vaccination group, the prevalence of HBsAg was 1.58% (57/3615), HBsAg(-)/anti-HBc(+) was 4.70% (170/3615), significantly lower than in the control group, which was 7.45% (231/3100) and 19.48% (640/3100) respectively (all p < 0.001). With aging, HBsAg(-)/anti-HBc(+) prevalence increased in the sampled participants from the control group (p_{for trend} < 0.001), but uncertain from the vaccination group. Of HBsAg(-)/anti-HBc(+), HBV-DNA was detected in 13.08% (17/130) from the vaccination group, and in 4.18% (12/287) from the control group. HBV rcDNA was detected in most sera that were tested positive for HBV-DNA.

CONCLUSIONS

OBI occurred in some vaccinated adults. However, neonatal HBV vaccination kept the effective protection against OBI in mature adults.

Overt and occult hepatitis B infection after neonatal vaccination: mother-to-infant transmission and HBV vaccine effectiveness

OBJECTIVES

Overt and occult hepatitis B infection (HBI) among mothers and infants were investigated, and the effectiveness of vaccination against HBI was evaluated based on transmission types.

METHODS

A hospital-based cohort was built with 2,734 mothers and 330 mother-infant pairs. Their demographic data were collected. Serological HBV markers, nested-PCR for HBV genes, viral load detection, and phylogenetic analysis were done.

RESULTS

The overall prevalence of HBI among mothers was 12.1% (330/2,734), with 10.4% for the overt type and 1.8% for the occult type. In 330 out of 1,650 (20%) mother-infant pairs, the overall, type-I (from overt mother to overt infant), type-II (from overt mother to occult infant), and type-Ⅲ (from occult mother to occult infant) transmissions were 1.9% (1/54), 5.6% (3/54) and 0.0% (0/7). The refinement of HBI classification improved the estimate of vaccine effectiveness against HBI from 74.4%-80.9% to 94.4%, which was more prominent for type-II. One mother-infant pair with type-II transmission shared nearly identical complete sequences. However, the high rate of lost-to-follow-up could not be ignored.

CONCLUSIONS

During the transition period, HBV is mainly transmitted from the overt type of HBI mother to infant. Intensive prenatal screening for mothers is vital.

Occult hepatitis B infection and hepatocellular carcinoma: Epidemiology, virology, hepatocarcinogenesis and clinical significance

Occult hepatitis B infection (OBI) refers to a condition where replication-competent HBV DNA is present in the liver, with or without HBV DNA in the blood, in individuals with serum HBsAg negativity assessed by currently available assays. The episomal covalently closed circular DNA (cccDNA) in OBI is in a low replicative state. Viral gene expression is mediated by epigenetic control of HBV transcription, including the HBV CpG island methylation pathway and post-translational modification of cccDNA-bound histone, with a different pattern from patients with chronic HBV infection. The prevalence of OBI varies tremendously across patient populations owing to numerous factors, such as geographic location, assay characteristics, host immune response, coinfection with other viruses, and vaccination status. Apart from the risk of viral reactivation upon immunosuppression and the risk of transmission of HBV, OBI has been implicated in hepatocellular carcinoma (HCC) development in patients with chronic HCV infection, those with cryptogenic or known liver disease, and in patients with HBsAg seroclearance after chronic HBV infection. An increasing number of prospective studies and meta-analyses have reported a higher incidence of HCC in patients with HCV and OBI, as well as more advanced tumour histological grades and earlier age of HCC diagnosis, compared with patients without OBI. The proposed pathogenetic mechanisms of OBI-related HCC include the influence of HBV DNA integration on the hepatocyte cell cycle, the production of pro-oncogenic proteins (HBx protein and mutated surface proteins), and persistent low-grade necroinflammation (contributing to the development of fibrosis and cirrhosis). There remain uncertainties about exactly how, and in what order, these mechanisms drive the development of tumours in patients with OBI.

Antiviral therapy for the sexually transmitted viruses: recent updates on vaccine development

INTRODUCTION

The sexually transmitted infections (STIs) caused by viruses including human T cell leukemia virus type-1 (HTLV-1), human immunodeficiency virus-1 (HIV-1), human simplex virus-2 (HSV-2), hepatitis C virus (HCV), hepatitis B virus (HBV), and human papillomavirus (HPV) are major public health issues. These infections can cause cancer or result in long-term health problems. Due to high prevalence of STIs, a safe and effective vaccine is required to overcome these fatal viruses.

AREAS COVERED

This review includes a comprehensive overview of the literatures relevant to vaccine development against the sexually transmitted viruses (STVs) using PubMed and Sciencedirect electronic search engines. Herein, we discuss the efforts directed toward development of effective vaccines using different laboratory animal models including mice, guinea pig or non-human primates in preclinical trials, and human in clinical trials with different phases.

EXPERT OPINION

There is no effective FDA approved vaccine against the sexually transmitted viruses (STVs) except for HBV and HPV as prophylactic vaccines. Many attempts are underway to develop vaccines against these viruses. There are several approaches for improving prophylactic or therapeutic vaccines such as heterologous prime/boost immunization, delivery system, administration route, adjuvants, etc. In this line, further studies can be helpful for understanding the immunobiology of STVs in human. Moreover, development of more relevant animal models is a worthy goal to induce effective immune responses in humans.

Downregulation of GSK3β and Upregulation of URG7 in Hepatitis B-Related Hepatocellular Carcinoma

: Hepatitis B virus (HBV) is the leading cause of hepatocellular carcinoma (HCC). The exact molecular contributors to the development of HBV-related HCC are not yet completely understood. Recent studies demonstrated that the deregulation of the Wnt pathway is highly associated with the development of HCC. Besides, HBV is known to have roles in the deregulation of this pathway. The present study evaluated the molecular aspects of the Wnt pathway in HBV-related HCC in liver tissue samples. Viral characterization was done by identifying the HBx mutations and the assessment of intrahepatic viral load. The expression of Wnt pathway genes was assessed using real-time PCR and methylation-specific PCR. The intrahepatic viral load was significantly higher in tumor samples than in normal tissues (P = 0.0008). Aberrant expression was observed in Wnt-1, Wnt-7a, FZD2, FZD7, β-catenin, URG7, c-Myc, SFRP5, and GSK3β, among which Wnt1, FZD2, SFRP5, Gsk3β, and URG7 were associated with HBV. HBx mutations at positions I88, L116, and I127 + F132 were associated with the decreased expression of GSK3β and overexpression of URG7 and Wnt1. Alterations in the expression level of β-catenin, as well as some mutants of HBx, were correlated with the level of c-Myc. HBV-related HCC seems to be mostly coordinated with epigenetic behaviors of HBx, such a multi-functional peptide with suppressing/trans-activating functions.

A recombinant human immunoglobulin with coherent avidity to hepatitis B virus surface antigens of various viral genotypes and clinical mutants

The hepatitis B virus (HBV) envelope is composed of a lipid bilayer and three glycoproteins, referred to as the large (L), middle (M), and small (S) hepatitis B virus surface antigens (HBsAg). S protein constitutes the major portion of the viral envelope and an even greater proportion of subviral particles (SVP) that circulate in the blood. Recombinant S proteins are currently used as a preventive vaccine, while plasma fractions isolated from vaccinated people, referred to as hepatitis B immune globulin (HBIG), are used for short-term prophylaxis. Here, we characterized a recombinant human IgG1 type anti-S antibody named Lenvervimab regarding its binding property to a variety of cloned S antigens. Immunochemical data showed an overall consistent avidity of the antibody to S antigens of most viral genotypes distributed worldwide. Further, antibody binding was not affected by the mutations in the antigenic ‘a’ determinant found in many clinical variants, including the immune escape mutant G145R. In addition, mutations in the S gene sequence that confer drug resistance to the viral polymerase did not interfere with the antibody binding. These results support for a preventive use of the antibody against HBV infection.

Occult Hepatitis B Virus Infection Prevalence Among Different Populations of Iran: A Systematic Review and Meta-Analysis

Context: Various frequency rates of occult hepatitis B virus infection (OBI) are reported from different parts of Iran. This systematic review and meta-analysis aimed to characterize the OBI epidemiology in Iran and estimate the pooled prevalence among different populations. Evidence Acquisition: Nine international and Persian electronic databases, as well as some conference proceedings, were searched. Original cross-sectional studies up to December 2018 were included if they investigated the prevalence of OBI by the detection of serum hepatitis B virus surface antigen and hepatitis B virus nucleic acid in at least 30 samples selected with any sampling methods. Comprehensive meta-analysis software was used to analyze the data, and Cochran’s Q-test and I-square statistics were applied to assess the heterogeneity. Meta-regression analysis was performed to assess the impact of the year of study on the OBI frequency. A P value < 0.05 was considered as the level of significance. Results: Of 412 citations found in electronic sources and 35 relevant citations added by searching the gray literature, 83 non-duplicated non-overlapping studies were evaluated. A total of 55 documents comprising 14,485 individuals from 16 provinces met the inclusion criteria and were used in the analysis. The prevalence of OBI considerably varied in different parts of the country with the highest prevalence (63.1%) reported among the HIV-positive population in Fars province. The rates of the OBI prevalence were estimated at 0.06% (95% CI: 0.02 - 0.16%) among blood donors (BDs) regardless of their anti-HBc status, 7.90% (95% CI: 4.33 - 13.99%) among anti-HBc positive BDs, 2.49% (95% CI: 1.2 - 4.81%) among hemodialysis (HD) patients, 4.44% (95% CI: 1.56 - 12.02%) among HIV-positive patients, and 7.76% (95% CI: 4.57 - 12.86%) among HCV-positive patients. No significant trends were observed in OBI prevalence rates among different groups over time (P > 0.05). Conclusions: This review revealed high rates of OBI prevalence among high-risk populations in Iran. It is strongly suggested that occult hepatitis B be investigated among populations with a high chance of its occurrence in our country.

The prevalence of occult HBV infection in immunized children with HBsAg-positive parents: a hospital-based analysis

Background and object

The risk of occult HBV infection (OBI) in children whose mothers are HBV carriers has received more widespread attention, but there were few reports to focus on the children with HBsAg-positive parents. In this study, we aimed to investigate the prevalence of OBI in immunized children with HBsAg-positive parents.

Methods

HBV-vaccinated Chinese hospitalized children with HBsAg-positive parents were analyzed in our investigation. Eligible subjects were tested using a standard nested PCR for all HBV genes, and analyzed by direct sequencing.

Results

There were 327 HBsAg-negative children included in the study out of about 9800 involved HBV-vaccinated hospitalized children. The positive rate of OBI was 3.1% (10/327) in the eligible children and 14.1% (46/327) with HBV DNA detectable. No significant differences were found between one and at least two regions positive groups (p > 0.05). The proportions of HBV DNA detectable in children with HBV father-carriers and mother-carriers were similar. The risk factors for HBV DNA-positive children could be male, anti-HBs levels, and anti-HBc positive.

Conclusion

There are 3.1% of OBIs and 14.1% of suspected OBI in vaccinated children with HBsAg-positive parents. The potential risk of suspected OBI in children with HBsAg-positive father should not be ignored. Anti-HBc positivity may be a useful seromarker for suspected OBI screening in vaccinated children. To prevent HBV breakthrough infection, accurate and convenient method is needed to detect OBI timely and exhaustively.

Electronic supplementary material

The online version of this article (10.1007/s12072-020-10055-9) contains supplementary material, which is available to authorized users.

High prevalence of occult hepatitis B infection (OBI) among healthy children and their parents in Alborz province, Iran; Vertical OBI, myth or truth?

BACKGROUND

Occult hepatitis B infection (OBI) has been described in various clinical settings including after hepatitis B virus (HBV) immunization. The purpose of study was to characterize the prevalence of OBI among immunized children from a subset of general population and the parents of OBI-positive cases.

METHODS

Sera of 1200 children from general population who have been previously immunized by HBV vaccine were assayed for anti-HBs. 660 were randomly selected for HBV DNA testing by different polymerase chain reaction (PCR) methods and were analysed by direct sequencing on surface genes.

RESULTS

None of participants were positive for HBsAg and anti-HBc. 549 (45.7%) and 651 (54.3%) cases had anti-HBs > 10 mIU/mL (responders) and < 10 mIU/mL (nonresponders) respectively. Of 660 selected specimens, 91 (16%) of children were positive for OBI. 23 (25.2%) and 68 (74.8%) of HBV DNA positive cases were belonged to responders and nonresponders, respectively, showing significant difference (P < .001). The mean levels of anti-HBs in OBI-positive and OBI-negative groups, showed no considerable variations. The mean viral load for OBI-positive cases showed substantial differences between responders and nonresponders (P = .007). Of 49 parents (98 individuals) of OBI-positive children 11 (22%) and 18 (36%) were positive for anti-HBc and anti-HBs respectively. Molecular testing was positive in 32 subjects (16 couples, 32.6%). In total, 6 mothers and 11 fathers were positive for OBI.

CONCLUSION

A proportion of OBI-positive vaccinated children could be existed in different populations. This finding could be arisen from vertical HBV transmission or vertical OBI possibly from their parents.

Conformational analysis of hepatitis B virus surface antigen mutations among HIV-positive patients diagnosed with occult hepatitis B virus

Aim: We analyzed the role of mutations on the conformational structure of hepatitis B surface antigen (HBsAg) among HIV-1 positive patients who were infected with occult hepatitis B. Methods: The effects of the potential impact of amino-acid substitutions on the 3D structures of the HBsAg and molecular ducking were investigated using bioinformatics software. Results: Mutations classified in seven groups in accordance with their positions in occult hepatitis B virus infection patients. Some substitutions of residues could linearize the ‘a’ determinant loops. The affinity of binding in mutant HBsAg structures to MAb 12 was lower compared with the wild ones. T123I and P127L substitutions were undergone decrease in HBsAg antigenicity. Conclusion: These findings could be beneficial for a better understanding of hepatitis B virus antigen/antibody interactions.

Baseline Hepatitis B Virus Titer Predicts Initial Postpartum Hepatic Flare: A Multicenter Prospective Study

BACKGROUND AND GOALS

A series of changes in the immune system occur during pregnancy and puerperium. Currently, we aim to characterize both the natural changes in liver inflammation and its association with hepatitis B viremia during this special period.

PATIENTS AND METHODS

Chronic hepatitis B (CHB) gravidas were recruited and followed up to 52 weeks postpartum. Virological and biochemical parameters were assessed throughout the period.

RESULTS

A total of 1097 CHB mothers had finished the entire follow-up including 451 accepting telbivudine, 178 accepting tenofovir, and 468 without antiviral therapy. Among the mothers, 11.94% went through hepatic flare in the first trimester and the rate decreased to 2.1% at the time of delivery. Nevertheless, a much higher frequency (19.78%) was observed in the early postpartum. Interestingly, alanine aminotransferase level decreased along with the development of pregnancy and then suddenly increased in the first month of puerperium. In addition, a downward trend was observed on the titer of HBsAg and HBeAg after delivery. Of note, an obvious higher frequency of alanine aminotransferase flare was revealed in mothers with high viremia (>6 log10 IU/mL). With multivariate analysis, only hepatitis B virus titer at baseline was strongly associated with hepatic flare during early postpartum (95% confidence interval, 1.012-3.049, P=0.045). The predictive rates of hepatic flare at baseline viral load of 6, 7, and 8 log10 IU/mL were 16.67%, 28.30%, and 30.60%, respectively.

CONCLUSIONS

CHB gravidas with high viremia should be monitored closely during entire pregnancy, and extended antiviral therapy is recommend to those mothers with baseline viremia >7 log10 IU/mL.

Update of the statements on biology and clinical impact of occult hepatitis B virus infection

In October 2018 a large number of international experts with complementary expertise came together in Taormina to participate in a workshop on occult hepatitis B virus infection (OBI). The objectives of the workshop were to review the existing knowledge on OBI, to identify issues that require further investigation, to highlight both existing controversies and newly emerging perspectives, and ultimately to update the statements previously agreed in 2008. This paper represents the output from the workshop.

Vertically acquired occult hepatitis B virus infection may become overt after several years

OBJECTIVES

To study the frequency of vertically acquired occult hepatitis B virus (HBV) infection (OBI).

METHODS

We investigated 44 children born to hepatitis B surface antigen (HBsAg) positive mothers. They received HBV vaccine directly after birth and at 2, 6 and 52 weeks of age; eight with HBeAg-positive mothers also received hepatitis B immunoglobulin (HBIG). HBV DNA was analyzed in blood collected at 6 weeks and 12 months of age, and HBV antibodies at 12 and 18 months of age.

RESULTS

HBV DNA, but not HBsAg or anti-HBc, was detected at 12 months of age in three children. The viral sequences were almost identical with HBV DNA from their mothers who all were HBeAg-positive and had received tenofovir during pregnancy. Follow-up at 5-7 years age showed that one of the three children had become seropositive for HBsAg and anti-HBc. This child and one of the other two had detectable HBV DNA at the follow-up, with whole genome sequences identical to those in HBV from their mothers.

CONCLUSIONS

Mothers-to-child transmission of HBV can, despite adequate prophylaxis, lead to OBI which may later develop into overt HBV infection. Whether such infections are of clinical importance needs to be further investigated.

Cost-effectiveness analysis of hepatitis B vaccine booster in children born to HBsAg-positive mothers in rural China

OBJECTIVE

In rural areas of China with highly endemic for hepatitis B virus (HBV) infection, protective efficacy was observed in adulthood when a one-dose HBV vaccine booster was administered to high-risk children born to mothers who were positive for hepatitis B surface antigen (HBsAg). The aim of this study was to estimate the cost-effectiveness of an HBV vaccine booster in this specific group of children when given at 10 years of age.

METHODS

Two potential strategies were considered: strategy 1 was a one-dose booster given if the child was negative on HBsAg screening; strategy 2 was a one-dose booster given if the child was negative on both HBsAg plus anti-HBs screening. A decision tree combined with a Markov model was developed to simulate the booster intervention process and to simulate the natural history of HBV infection in a cohort of 10-year-old children who were born to HBsAg-positive mothers. The model was calibrated based on multiple selected outcomes. Costs and quality-adjusted life years (QALYs) were measured from a societal perspective. Cost-effectiveness ratios (CERs) of the different strategies were compared in both base-case and one-way sensitivity analyses.

RESULTS

Compared to the current practice of 'no screening and no booster', both strategy 1 and strategy 2 were cost-saving, with CERs estimated at US$ -6961 and US$ -6872 per QALY gained, respectively. In the one-way sensitivity analysis for strategy 1, all the CERs were found to be less than US$ -5000 per QALY gained after considering the uncertainty of all the variables, including vaccination protective efficacy, natural history, behavior, and various costs and utility weights. In a 'worst case' scenario (all parameter values simultaneously being at the worst), the CER of strategy 1 increased to US$ 3263 per QALY gained, which was still less than the GDP per capita of China in 2016 (US$ 8126).

CONCLUSIONS

A hepatitis B vaccine booster given to children born to HBsAg-positive mothers in rural China would be cost-effective and could be considered in HBV endemic areas.

Molecular Characterization of Near Full-Length Genomes of Hepatitis B Virus Isolated from Predominantly HIV Infected Individuals in Botswana

The World Health Organization plans to eliminate hepatitis B and C Infections by 2030. Therefore, there is a need to study and understand hepatitis B virus (HBV) epidemiology and viral evolution further, including evaluating occult (HBsAg-negative) HBV infection (OBI), given that such infections are frequently undiagnosed and rarely treated. We aimed to molecularly characterize HBV genomes from 108 individuals co-infected with human immunodeficiency virus (HIV) and chronic hepatitis B (CHB) or OBI identified from previous HIV studies conducted in Botswana from 2009 to 2012. Full-length (3.2 kb) and nearly full-length (~3 kb) genomes were amplified by nested polymerase chain reaction (PCR). Sequences from OBI participants were compared to sequences from CHB participants and GenBank references to identify OBI-unique mutations. HBV genomes from 50 (25 CHB and 25 OBI) individuals were successfully genotyped. Among OBI participants, subgenotype A1 was identified in 12 (48%), D3 in 12 (48%), and E in 1 (4%). A similar genotype distribution was observed in CHB participants. Whole HBV genome sequences from Botswana, representing OBI and CHB, were compared for the first time. There were 43 OBI-unique mutations, of which 26 were novel. Future studies using larger sample sizes and functional analysis of OBI-unique mutations are warranted.

Hepatitis B virus infection: Defective surface antigen expression and pathogenesis

Hepatitis B virus (HBV) infection is a global public health concern. HBV causes chronic infection in patients and can lead to liver cirrhosis, hepatocellular carcinoma, and other severe liver diseases. Thus, understanding HBV-related pathogenesis is of particular importance for prevention and clinical intervention. HBV surface antigens are indispensable for HBV virion formation and are useful viral markers for diagnosis and clinical assessment. During chronic HBV infection, HBV genomes may acquire and accumulate mutations and deletions, leading to the expression of defective HBV surface antigens. These defective HBV surface antigens have been found to play important roles in the progression of HBV-associated liver diseases. In this review, we focus our discussion on the nature of defective HBV surface antigen mutations and their contribution to the pathogenesis of fulminant hepatitis B. The relationship between defective surface antigens and occult HBV infection are also discussed.

Immune-escape mutations and stop-codons in HBsAg develop in a large proportion of patients with chronic HBV infection exposed to anti-HBV drugs in Europe

Background

HBsAg immune-escape mutations can favor HBV-transmission also in vaccinated individuals, promote immunosuppression-driven HBV-reactivation, and increase fitness of drug-resistant strains. Stop-codons can enhance HBV oncogenic-properties. Furthermore, as a consequence of the overlapping structure of HBV genome, some immune-escape mutations or stop-codons in HBsAg can derive from drug-resistance mutations in RT. This study is aimed at gaining insight in prevalence and characteristics of immune-associated escape mutations, and stop-codons in HBsAg in chronically HBV-infected patients experiencing nucleos(t)ide analogues (NA) in Europe.

Methods

This study analyzed 828 chronically HBV-infected European patients exposed to ≥ 1 NA, with detectable HBV-DNA and with an available HBsAg-sequence.

The immune-associated escape mutations and the NA-induced immune-escape mutations sI195M, sI196S, and sE164D (resulting from drug-resistance mutation rtM204 V, rtM204I, and rtV173L) were retrieved from literature and examined. Mutations were defined as an aminoacid substitution with respect to a genotype A or D reference sequence.

Results

At least one immune-associated escape mutation was detected in 22.1% of patients with rising temporal-trend. By multivariable-analysis, genotype-D correlated with higher selection of ≥ 1 immune-associated escape mutation (OR[95%CI]:2.20[1.32–3.67], P = 0.002). In genotype-D, the presence of ≥ 1 immune-associated escape mutations was significantly higher in drug-exposed patients with drug-resistant strains than with wild-type virus (29.5% vs 20.3% P = 0.012). Result confirmed by analysing drug-naïve patients (29.5% vs 21.2%, P = 0.032). Strong correlation was observed between sP120T and rtM204I/V (P < 0.001), and their co-presence determined an increased HBV-DNA.

At least one NA-induced immune-escape mutation occurred in 28.6% of patients, and their selection correlated with genotype-A (OR[95%CI]:2.03[1.32–3.10],P = 0.001).

Finally, stop-codons are present in 8.4% of patients also at HBsAg-positions 172 and 182, described to enhance viral oncogenic-properties.

Conclusions

Immune-escape mutations and stop-codons develop in a large fraction of NA-exposed patients from Europe. This may represent a potential threat for horizontal and vertical HBV transmission also to vaccinated persons, and fuel drug-resistance emergence.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3161-2) contains supplementary material, which is available to authorized users.

Impact of immune escape mutations and N-linked glycosylation on the secretion of hepatitis B virus virions and subviral particles: Role of the small envelope protein

Hepatitis B virus (HBV) expresses three co-terminal envelope proteins: large (L), middle (M), and small (S), with the S protein driving the secretion of both virions and subviral particles. Virion secretion requires N-linked glycosylation at N146 in the S domain but can be impaired by immune escape mutations. An M133T mutation creating a novel glycosylation site at N131could rescue virion secretion of N146Q mutant (loss of original glycosylation site) and immune escape mutants such as G145R. Here we demonstrate that other novel N-linked glycosylation sites could rescue virion secretion of the G145R and N146Q mutants to variable extents. Both G145R and N146Q mutations impaired virion secretion through the S protein. The M133T mutation restored virion secretion through the S protein, and could work in trans. Impaired virion secretion was not necessarily associated with a similar block in the secretion of subviral particles.

Revaccination against hepatitis B in late teenagers who received vaccination during infancy: Yes or no?

The significance of vaccination against hepatitis B during infancy is recognized worldwide, however, whether booster or revaccination after a period of time following the primary vaccination is required remains controversial. Recently, cross-sectional epidemiological surveys found that HBsAg prevalence in subjects born after the implementation of mass vaccination was increased with age, which was attributed to waning of anti-HBs over time. However, comprehensive analysis of the closely related cross-sectional surveys showed that the age-specific increased HBsAg prevalence was more likely associated with the carry-over of the infection occurred in early life, likely due to imperfect coverage of hepatitis B vaccination at the beginning of its introduction. Latest studies showed that booster response could be observed in the majority of individuals vaccinated 30 years ago. Moreover, confirmed breakthrough HBV infection with severe consequences in successfully vaccinated individuals is extremely rare. Thus far no compelling evidence has been acquired to support booster vaccination in adolescence. The uncertainty regarding the duration of protection of hepatitis B vaccination, especially beyond 30 years after the primary vaccination, merits a systematically designed study to follow the same cohort of participants longitudinally, which differs from the cross-sectional studies reported previously, can hopefully offer more direct evidence to help us to determine whether revaccination of hepatitis B vaccine is necessary.

Contribution of hepatitis B virus and hepatitis C virus to liver cancer in China north areas: Experience of the Chinese National Cancer Center

INTRODUCTION

The aim of this study was to determine the impact of hepatitis B virus (HBV) and/or hepatitis C virus (HCV) on primary liver cancer (PLC) in China north areas.

METHODS

A total of 2172 histologically confirmed PLC patients attending the National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences during the period January 1, 2003 to December 31, 2014 were enrolled. Details of hepatitis B surface antigen (HBsAg), antibodies against HBV core antigen (anti-HBc), and antibodies against HCV (anti-HCV) status were recorded. Sequencing of the HBV PreS-S gene and the C/E1 and NS5B fragments of HCV was performed and the genotypes were analyzed for some of the patients with hepatocellular carcinoma (HCC).

RESULTS

Among the 2172 histologically confirmed PLC cases, 1823 (83.9%) had HCC and 238 (11.0%) had intrahepatic cholangiocarcinoma (iCCA). Among HCC cases, HBV infection alone, indicated by HBsAg-neg/pos+anti-HBc-pos, was found in 1567 (86.0%) cases; of these, 18.2% (331/1823) were HBsAg-neg+anti-HBc-pos. Serum HBV-DNA was detectable in 70% of HBsAg-neg+anti-HBc-pos HCC cases. The dominant HBV genotype was HBV-C2 (94.4%). HCV infection alone, indicated by anti-HCV-pos, was found in 2.5% (46/1823) of cases; HCV-1b (72.1%) was the dominant genotype. HBV+HCV co-infection markers were found in 6.7% (122/1823) of cases. Only 88 (4.8%) cases had no HBV and no HCV markers. Among the 238 iCCA cases, 54 (22.7%) were HBsAg-pos+anti-HBc-pos; none was anti-HCV-pos alone.

CONCLUSIONS

HBV remains the major contributor to PLC in China north areas Individuals with occult HBV infection should not be ignored in liver cancer screening.

High Rates of Occult Hepatitis B Virus Infection in HIV-Positive Individuals Initiating Antiretroviral Therapy in Botswana

Background

Hepatitis B surface antigen (HBsAg)–negative but hepatitis B virus (HBV) DNA-positive infection—known as occult hepatitis B infection (OBI)—occurs in 1% to >15% of HIV-positive individuals in the United States and South Africa, respectively. However, there are no data on OBI from Botswana, a country known to be hyperendemic for chronic HBV infection and to have a significant HIV burden.

Methods

Two hundred seventy-two adults enrolled in an HIV treatment study of tenofovir/emtricitabine as the nucleoside backbone who were previously determined to be HBsAg negative were tested for HBV DNA at baseline and 1 year after initiation of highly active antiretroviral therapy (HAART).

Results

HBV DNA was detected in 72 of 272 (26.5%). Six individuals (8.3%) had HBV DNA levels greater than 200 IU/mL, and the highest viral load was 3280 IU/mL. Of 65 participants with OBI evaluated at 12 months after initiating HAART, only 1 (1.5%) had detectable HBV DNA.

Conclusions

Occult HBV infection is quite common in HIV-infected patients in Botswana, although its impact on the course of HIV disease progression is unknown. The suppression of occult HBV DNA levels by tenofovir/emtricitabine suggests an effective therapeutic option, although the long-term suppressive abilities remain unstudied.

Occult hepatitis B virus infection in immunized children born to carrier mothers

BACKGROUND

The prevalence of occult hepatitis B virus (HBV) infection (OBI) in children due to mother-to-child transmission (MTCT) despite immunoprophylaxis remains controversial and is still unknown in Japan. The aim of this study was to determine the OBI prevalence in such children in Japan and identify the genomic mutations that might be associated with the pathogenesis of OBI in children.

METHODS

The data on 158 children born to HBV carrier mothers and who received complete passive-active immunoprophylaxis after birth in 2002-2014 were reviewed. HBV markers were detected using commercial enzyme-linked immunosorbent assay kits. HBV-DNA was detected using real-time and nested polymerase chain reaction. Complete genomic sequences were determined.

RESULTS

Among the 158 children studied, three had HBV MTCT: two had OBI, and one had resolved HBV infection (RBI). The prevalence of OBI and RBI was estimated to be 1.3% and 0.6%, respectively. The HBV genomes of the two OBI children were wild type and 100% identical to those of their mothers. Of these two children, one received repeated hepatitis B immunoglobulin (HBIG) and developed overt HBV infection. Her HBV genome had a G145R mutation in the S gene that might have been induced by HBIG treatment. The RBI child was persistently positive for antibody to HBV core antigen (10-12 signal/cut-off ratio; S/CO).

CONCLUSIONS

A low prevalence of OBI was observed in children who received immunoprophylaxis for preventing MTCT in Japan. The development of overt HBV infection in infants with OBI indicates the necessity of close and long-term monitoring.

Overt and occult hepatitis B virus infection among community children in Northwest China

Although a universal newborn hepatitis B (HB) immunization programme has been implemented in China, hepatitis B virus (HBV) breakthrough infection, including HB surface antigen (HBsAg)-positive infection and occult HBV infection (OBI), still occurs during infancy or childhood. Obtaining the actual prevalence of HBV infection in general children is important for preventing and controlling the spread of HB. Accordingly, we investigated the prevalence of overt infection and OBI in community children and compared the serological and virological characteristics of OBI and HBsAg carrier children to clarify the mechanisms related to OBI. In total, 6 706 community children <12 years of age were included from a population-based HBV seroepidemiological investigation in Northwest China. The HBsAg carrier rate in community children was 1.60% (107/6706), and the anti-HBs positive rate was 57.35% (3846/6706). Additionally, 1192 HBsAg-negative children were examined for OBI using nested PCR. The prevalence of OBI in local children was 1.26% (15/1192), and the predominant OBI genotypes were C and D. The 15 OBI children and 29 HBsAg-positive children from the same population did not have a statistical significant difference in age, gender, alanine aminotransferase (ALT), proportion of anti-HBs or anti-HBc, viral genotypes or mutations. Children with chronic overt infection had higher viral loads than OBI children (P=.004). These results suggested that HBV overt and occult infection of children was more serious in underdeveloped north-west regions. HBV neonatal immunization and catch-up programmes should be strengthened and supplemented. None of specific viral mutations or genotypes related to OBI were found. OBI may be a specific stage of HBV infection.

Temporal trend of hepatitis B surface mutations in the post-immunization period: 9 years of surveillance (2005-2013) in eastern China

Limited information is available about the temporal trend in the prevalence and evolution of hepatitis B virus (HBV) S-gene mutations in the post-immunization era in China. From 2005 to 2013, 1077 hepatitis B cases under 15 years of age reported through Chinese National Notifiable Disease Reporting System (NNDRS) were successfully sequenced of S-gene in Shandong province, China. A total of 97 (9.01%) cases had amino acid (aa) substitution in the “α” determinant of HBsAg. The yearly prevalence from 2005 to 2013 maintained at a relatively stable level, and showed no significant change (P > 0.05). Multivariate logistic regression analysis demonstrated that the prevalence of “α” mutations was independently associated with the maternal HBsAg status (P < 0.05), and not with surveillance year and hepatitis B vaccination (P > 0.05). The hottest mutation position was aa126 (I126S/N and T126A, 29.63%), and aa 145 (G145R/A, 25.93%). Mutated residue 126 tended to occur less frequent, while that of residue 145 was more frequent with increasing year. Our data showed that there was no increase in the frequency of HBV “α” mutations over time during the post-immunization period. However, long-term vaccination might enhance the change of HBV mutational pattern, and G145 mutation was becoming dominant.

Hepatitis B virus infection assessed 3 to 18 years after vaccination in Cuban children and adolescents born to HBsAg-positive mothers

Thirty-two participants, aged between 3-18 years, born to hepatitis B surface antigen (HBsAg)-positive mothers and vaccinated at birth were analyzed for hepatitis B virus (HBV) infection. Overall, 56% had anti-HB titers ≥10 IU/L; five were positive for antibodies to the core antigen (anti-HBc), and two of these were also positive for HBsAg/DNA. One of the HBsAg/anti-HBc double-negative children presented with an unusual occult infection (HBV DNA-positive). No known vaccine escape mutations were detectable. Our data suggest that the vaccine protected 93.8% of children in this high-risk group against chronic HBV infection. Occult infections should be considered even in countries with low endemicity and high vaccination coverage.

Low Level of Hepatitis B Virus Infection in Children 20 Years After Initiation of Infant Vaccination Program in Wallis and Futuna

The prevalence of hepatitis B virus (HBV) in Wallis and Futuna (WAF) was one of the highest in the Pacific and was the driving factor for introducing hepatitis B (HepB) vaccination in 1992 and HepB birth dose (HepB-BD) in 2006. Using lymphatic filariasis (LF) transmission assessment survey (TAS) as a survey platform for eliminating LF, we assessed HBV surface antigen (HBsAg) seroprevalence, HepB vaccination coverage, and its timeliness among schoolchildren in WAF. From one finger prick of all registered fourth and fifth grade students, we tested HBsAg and filariasis antigen simultaneously, and estimated HepB vaccination coverage and timeliness by reviewing students' immunization cards. Since the children targeted were born when the three-dose HepB schedule was 2, 3, and 8 months, we defined timely vaccination if each dose was given by 3, 4, and 12 months. Of 476 targeted, 427 were enrolled. HBsAg prevalence was 0.9%. Estimated HepB vaccination coverage was 97%, 97%, and 96% for the first, second, and third doses, respectively, yielding coverage for all three doses of 96%. Proportion of timely vaccination was lower: 80%, 56%, and 65%, respectively, and less than 50% for all three doses combined. The seroprevalence of HBsAg among schoolchildren in WAF is less than 1%, close to the control goal. HepB vaccination coverage was high, but many children were vaccinated late. We recommend increasing the efforts for timely HepB vaccination. By combining an HBV seroprevalence survey and coverage assessment, we demonstrated the benefit of using TAS as a public health platform to access schoolchildren.

Vertical transmission of hepatitis B virus during pregnancy and delivery in Denmark

OBJECTIVE

In Denmark, pregnant women have been screened for hepatitis B virus (HBV) since 2005, and children born to HBV-infected mothers offered hepatitis B immunoglobulin at birth, vaccination against HBV at birth and after 1, 2 and 12 months. The purpose of this study was to determine the risk of vertical HBV transmission in children born to mothers with chronic HBV infection, to investigate the antibody response in the children and to investigate possible maternal predictive risk factors for HBV transmission.

MATERIALS AND METHODS

Through the Danish Database for Hepatitis B and C, we identified 589 HBV-infected women who had given birth to 686 children, of whom 370 children were born to 322 women referred to hospital. 132 (36%) children, born to 109 mothers, were included in the study; 128 children had blood samples tested for HBsAg, anti-HBc (total), anti-HBs and HBV-DNA and four children had saliva samples tested for anti-HBc.

RESULTS

We found vertical HBV transmission in Denmark to be 2.3% [95% CI: 0.5, 6.5], a high proportion of HBsAg-negative children with low levels of anti-HBs (18.4%) and a high proportion (15.2%) with resolved HBV infection. No maternal risk factor was statistically significantly associated with HBV vertical transmission.

CONCLUSION

In a HBV low prevalence setting as Denmark, despite a national vaccination program, vertical HBV transmission occurred in 2.3% of children born to HBV-infected mothers. In addition, a high proportion of the children had insufficient anti-HBs levels and a high proportion had serological signs of resolved HBV infection.

Adolescent booster with hepatitis B virus vaccines decreases HBV infection in high-risk adults

BACKGROUND

Neutralizing antibodies (anti-HBs) after immunization with hepatitis B virus (HBV) vaccines against HBV surface antigen (HBsAg) wane after 10-15years. We analyzed the effect of an adolescent booster given to vaccination-protected children born to mothers with different HBsAg-carrying status against HBV infection in their mature adulthood.

METHODS

A total of 9793 individuals, who were HBsAg-negative at childhood (baseline) and donated blood samples, both during childhood and adulthood, from the vaccination group in "Qidong Hepatitis B Intervention Study", were enrolled. Among them 7414 received a one-dose, 10μg-recombinant HBV vaccine booster at 10-14years of age. At endpoint (23-28years of age), we determined the HBV serological markers and quantified their serum HBV-DNA in each of the chronic HBV-infected adults.

RESULTS

Fifty-seven adults were identified as chronic HBV infection, indicated by HBsAg(+)&anti-HBc(+) for more than 6months. The individuals who were born to HBsAg-positive mothers (high-risk adults) had significantly increased risk of developing chronic HBV infections in adulthood compared with those who were born to HBsAg-negative mothers; the adjusted odds ratio (OR) was 12.56, 95%CI:7.14-22.08. The seronegative status of anti-HBs at 10-11years of age significantly increased the risk of HBV infections among the high-risk adults. When HBsAg(-)&anti-HBc(+) children who were born to HBsAg-positive mothers 70% of them remained as the status and 10% of them developed HBsAg(+)&anti-HBc(+). While when they were born to HBsAg-negative mothers 1.05% HBsAg(-)&anti-HBc(+) children developed HBsAg(+)&anti-HBc(+) and 24.74% of them remained as the status in 12-18years. One dose of adolescent booster showed significant protection on high-risk adults from chronic HBV infection; P for trend was 0.015.

CONCLUSIONS

Maternal HBsAg-positive status was an independent risk factor for vaccination-protected children to develop HBV breakthrough infection in adulthood. Adolescent boosters might be appropriate for high-risk individuals who were born to HBsAg-positive mothers when their serum anti-HBs<10mIU/ml.

Minimization of hepatitis B infection among children in Jiangsu, China, 12years after integration of hepatitis B vaccine into the expanded program on immunization

BACKGROUND

China has integrated hepatitis B vaccine into the Expanded Program on Immunization since 2002. We aimed to survey the seroprevalence of and immunity to hepatitis B virus (HBV) in children born from 2002 to 2014 in Jiangsu, China.

METHODS

Totally 3442 children (M:F=2072:1370) at the age of 7months to 12years (5.5±3.6), from five cities and rural areas across Jiangsu province, were enrolled. Blood samples were measured for HBV markers by ELISA and quantitative microparticle enzyme immunoassay. HBV DNA was tested by real-time PCR and S region was amplified by nested PCR.

RESULTS

Twelve (0.35%) children were positive for hepatitis B surface antigen (HBsAg) and 34 (0.99%) were HBsAg negative and positive for antibody against hepatitis B core antigen (anti-HBc). Totally 2542 (73.85%) children had anti-HBs levels ⩾10mIU/ml and 535 (15.54%) with 2-9.9mIU/ml. All 12 HBsAg-positive children had detectable HBV DNA with a mean level of 6.1±1.7logIU/ml (3.3-8.1logIU/ml); 8 were genotype C and 4 were genotype B. No mutation was detected in the a determinant of HBsAg. HBV DNA was not detected in all the 34 children with positive anti-HBc and negative HBsAg.

CONCLUSION

HBsAg prevalence among children in Jiangsu born after the introduction of universal vaccination against hepatitis B has significantly decreased. No mutation of S gene is associated with vaccine failure in the cohort of children.

Occult HBV Infection in Immunized Neonates Born to HBsAg-Positive Mothers: A Prospective and Follow-Up Study

Objective

Occult HBV infection (OBI) has been reported in infants born to HBsAg-positive mothers despite immunization. This study aims to determine the maintenance of this status in a prospective birth cohort.

Methods

A total of 158 neonates born to HBsAg-positive mothers were enrolled. All received passive-active immunization against HBV according to a 0-1-6 schedule. Sera were collected at 7 months of age. Those diagnosed with OBI were serially followed up at 12, 24 and 36 months of age. HBV serological markers were determined by Abbott i2000 system. HBV DNA was quantitated by Abbott m2000 system. Standard PCR followed by direct sequencing were applied for mother-child HBV pairs. Homology and phylogenetic comparisons were done by BLAST and Mega 5.

Results

All the 158 neonates were HBsAg-negative and anti-HBs-positive at 7 months of age, and 32 (20.3%) of them were diagnosed with OBI, with a median HBV DNA level of 1.97 (1.20–3.71) log IU/mL. Of them, HBV DNA was positive in 25.0%, 21.9% and 7.7% at 12, 24 and 36 months of age, respectively. HBV DNA disappeared at one of the follow-up points in 31 neonates, however, rebounded to low levels in 6 of them thereafter. HBV DNA persisted at low levels during follow-ups in the other one neonate apart from the above 31. All remained negative for HBsAg. Only two (6.3%) neonates were positive for anti-HBc after 24 months of age. HBV showed close homology and phylogenetic relationships for mother-child pairs. S-escape mutant, G145R, was not discovered. The first vaccine dose within 6 hours of birth significantly reduced the occurrence of OBI (59.4% vs. 83.3%, p = 0.003).

Conclusions

HBV may be controlled in immunized neonates of HBsAg-positive mothers, after being diagnosed with OBI. Timely vaccination against HBV may provide the utmost protection. Long-term and close monitorings are needed.

Impacts of the G145R Mutation on the Structure and Immunogenic Activity of the Hepatitis B Surface Antigen: A Computational Analysis

BACKGROUND

Vaccine-escaped hepatitis B virus (HBV) mutations occur within the "a" determinant area, which is located in the major hydrophilic region (MHR) of the hepatitis B surface antigen (HBsAg) protein. It is now well established that the common G145R mutation is highly capable of escaping from HBsAg immune recognition. However, the impacts of this mutation on the structure and immunogenic activity of HBsAg have been poorly investigated.

OBJECTIVES

The present study analyzed the effects of the G145R mutation on the structure and immunogenic activity of the HBsAg.

MATERIALS AND METHODS

Three-dimensional (3D) structure of HBsAg for both the wild-type and G145R mutant were predicted and refined using several web tools. After quantitative evaluations, the effects of the G145R mutation on the secondary and 3D structures of the HBsAg were investigated. In parallel, the immunogenic activity of the wild-type and mutant HBsAg was also analyzed using a ClusPro docking server as well as the IEDB web tool. Further analyses were performed via molecular dynamics (MD) simulations using the GROMACS v5.0.2 simulation package.

RESULTS

The G145R mutation causes a considerable reduction in the immunogenic activity of the HBsAg through a conformational change in the HBsAg antigenic loops. This mutation inserts a new β-strand in the "a" determinant region of the HBsAg, leading to a reduced binding affinity to its monoclonal antibody, MAb12. The G145R mutation also increased the compactness and stability of the HBsAg by enhancing the rigidity of the "a" determinant.

CONCLUSIONS

These data will be beneficial for designing more advanced antibodies for the recognition of the HBsAg in diagnostics. In addition, the results of this study may assist in the design or development of more effective hepatitis B vaccines.

An "immune barrier" is formed in the placenta by hepatitis B immunoglobulin to protect the fetus from hepatitis B virus infection from the mother

The effect of hepatitis B immunoglobulin (HBIG) on hepatitis B virus (HBV) DNA load and its protective mechanism are not well understood. Twenty-eight hepatitis B surface antigen (HBsAg)–positive pregnant women and their newborns were assigned to an experimental (n = 12) or control group (n = 16) according to whether they received HBIG during pregnancy. HBV DNA load and markers titer of the mothers and newborns were tested. These markers and HBV DNA load in mothers of the experimental group did not fluctuate significantly and were comparable to the control. In the experimental group, there was a positive correlation between mothers and their newborns with regard to hepatitis B surface antibody titer. Immunohistochemical staining of placenta sections showed that HBsAg-positive areas mainly included trophoblastic cells and villous mesenchymal cells without HBIG colocalization, whereas HBIG-positive areas principally included villous capillary endothelial cells and villous mesenchymal cells. Additionally, compared with the control group, the positive rate and mean density of HBIG in the experimental group were remarkably higher. HBIG deposition was seen in Hofbauer cells. Thus, rather than influencing virus replication, HBIG forms an immune barrier between the mother and fetus to prevent HBV transmission.