Cellular immune response to HBcAg in mother-to-infant transmission of hepatitis B virus

IFN-γ decreases PD-1 in T lymphocytes from convalescent COVID-19 patients via the AKT/GSK3β signaling pathway

Post-COVID-19 syndrome may be associated with the abnormal immune status. Compared with the unexposed age-matched elder group, PD-1 in the CD8+ T cells from recovered COVID-19 patients was significantly lower. IFN-γ in the plasma of COVID-19 convalescent patients was increased, which inhibited PD-1 expression in CD8+ T cells from COVID-19 convalescent patients. scRNA-seq bioinformatics analysis revealed that AKT/GSK3β may regulate the INF-γ/PD-1 axis in CD8+ T cells from COVID-19 convalescent patients. In parallel, an IFN-γ neutralizing antibody reduced AKT and increased GSK3β in PBMCs. An AKT agonist (SC79) significantly decreased p-GSK3β. Moreover, AKT decreased PD-1 on CD8+ T cells, and GSK3β increased PD-1 on CD8+ T cells according to flow cytometry analysis. Collectively, we demonstrated that recovered COVID-19 patients may develop long COVID. Increased IFN-γ in the plasma of recovered Wuhan COVID-19 patients contributed to PD-1 downregulation on CD8+ T cells by regulating the AKT/GSK3β signaling pathway.

Atypical Hepatitis B Virus Serology Profile-Hepatitis B Surface Antigen-Positive/Hepatitis B Core Antibody-Negative-In Hepatitis B Virus/HIV Coinfected Individuals in Botswana

(1) Background: Hepatitis B core antibodies (anti-HBc) are a marker of hepatitis B virus (HBV) exposure; hence, a normal HBV serology profile is characterized by HBV surface antigen (HBsAg) and anti-HBc positivity. However, atypical HBV serologies occur, and we aimed to determine the prevalence of an atypical profile (HBsAg+/anti-HBc-) in a cohort of people with HIV-1 (PWH) in Botswana. (2) Methods: Plasma samples from an HIV-1 cohort in Botswana (2013-2018) were used. The samples were screened for HBsAg and anti-HBc. Next-generation sequencing was performed using the GridION platform. The Wilcoxon rank-sum test and Chi-squared tests were used for the comparison of continuous and categorical variables, respectively. (3) Results: HBsAg+/anti-HBc- prevalence was 13.7% (95% CI 10.1-18.4) (36/263). HBsAg+/anti-HBc- participants were significantly younger (p < 0.001), female (p = 0.02) and ART-naïve (p = 0.04) and had a detectable HIV viral load (p = 0.02). There was no statistically significant difference in the number of mutations observed in participants with HBsAg+/anti-HBc- vs. those with HBsAg+/anti-HBc+ serology. (4) Conclusions: We report a high HBsAg+/anti-HBc- atypical serology profile prevalence among PWH in Botswana. We caution against HBV-testing algorithms that consider only anti-HBc+ samples for HBsAg testing, as they are likely to underestimate HBV prevalence. Studies to elucidate the mechanisms and implications of this profile are warranted.

HBeAg-Negative/Anti-HBe-Positive Chronic Hepatitis B: A 40-Year-Old History

Hepatitis B “e” antigen (HBeAg) negative chronic hepatitis B (CHB), 40 years since discovery in the Mediterranean area, has become the most prevalent form of HBV-induced liver disease worldwide and a major health care burden caused by HBV infection. A great deal of knowledge accumulated over the last decades provides consistent evidence on the bimodal dynamics of the expression of structural and non-structural forms of the viral core proteins which associate with different virologic and clinic–pathologic outcomes of HBV infection. In absence of serum HBeAg, the presence and persistence of HBV replication causes and maintains virus-related liver injury. Thus, in clinical practice it is mandatory to screen HBV carriers with HBeAg-negative infection for the early diagnosis of HBeAg-negative CHB since antiviral therapy can cure HBV-induced liver disease when started at early stages.

Controversies in Treating Chronic Hepatitis B Virus Infection: Discordant Serologic Results

Despite effective vaccines and approved therapeutic agents, hepatitis B virus (HBV) remains a prevalent global health problem. Current guidelines rely on a combination of serologic, virological, and biochemical markers to identify the phase in the natural history of chronic HBV infection. Discordant serologic results can occur, which may lead to misclassification. Commonly encountered results that differ from the typical profiles seen in chronic HBV infection are described. For each scenario, the frequency of occurrence, possible explanations, and recommendations for clinical management are discussed. Recognition of discordant serologic findings is crucial for optimal clinical decision.

Natural History of Untreated HBeAg-Positive Chronic HBV Infection With Persistently Elevated HBV DNA but Normal Alanine Aminotransferase

Nucleos(t)ide analogues (NUCs) are not routinely recommended for patients with hepatitis B e antigen–positive chronic hepatitis B virus (HBV) infection who have persistently elevated serum HBV DNA level (>20,000 IU/mL) but normal alanine aminotransferase (<40 IU/L) level. Here, we evaluated the cumulative risks of hepatocellular carcinoma (HCC) in such patients (the untreated persistently elevated serum HBV DNA [pEDNA] group) compared with inactive carriers (the IC group).

Successful treatment of infantile hepatitis B with lamivudine: A case report

BACKGROUND

How to treat infantile hepatitis B virus (HBV) infection remains a controversial issue. The nucleoside analogue lamivudine (LAM) has been approved to treat children (2 to 17 years old) with chronic hepatitis B. Here, we aimed to investigate the benefit of LAM treatment in infantile hepatitis B.

CASE SUMMARY

A 4-mo-old infant born to a hepatitis B surface antigen (HBsAg)-positive woman was found to be infected by HBV during a health checkup. Liver chemistry and HBV seromarker tests showed alanine aminotransferase of 106 U/L, HBsAg of 685.2 cut-off index, hepatitis B “e” antigen of 1454.0 cut-off index, and HBV DNA of > 1.0 × 10⁹ IU/mL. LAM treatment (20 mg/d) was initiated, and after 19 mo, serum HBsAg was entirely cleared and hepatitis B surface antibody was present. The patient received LAM treatment for 2 years in total and has been followed for 3 years. During this period, serum hepatitis B surface antibody has been persistently positive, and serum HBV DNA was undetectable.

CONCLUSION

Early treatment of infantile hepatitis B with LAM could be safe and effective.

Prevention of Hepatitis B Virus Infection and Liver Cancer

Hepatocellular carcinoma (HCC) is one of the five leading causes of cancer death in human. Hepatitis B virus (HBV) is the most common etiologic agent of HCC in the world. Prevention is the best way to control cancer. There are three levels of liver cancer prevention, i.e., primary prevention by HBV vaccination targeting the general population starting from birth dose, secondary prevention by antiviral agent for high-risk subjects with chronic HBV infection, and tertiary prevention by antiviral agent to prevent recurrence for patients who have been successfully treated for liver cancer. Primary prevention by hepatitis B vaccination is most cost effective, the cancer preventive efficacy support it as the first successful example of cancer preventive vaccine in human. Addition of hepatitis B immunoglobulin immediately after birth and antiviral agent during the third trimester of pregnancy to block mother-to-infant transmission of HBV are existing or possible emerging strategies to enhance the prevention efficacy of HBV infection and its related liver cancer. Secondary prevention with current antiviral agents may reduce the risk or delay the onset of HCC development, but could not eradicate HBV infection and HCC. Better antiviral therapeutic agents are needed for better secondary prevention.

Effects of intrauterine exposure to maternal-derived HBeAg on T cell immunity in cord blood

Immature immune system and immune tolerance induced by exposure to HBeAg in utero and/or shortly after infection in newborns were reportedly the causes of chronic HBV infection. To investigate the effect of maternal-derived HBeAg on neonatal T cell immunity, we analysed and compared T cell phenotypes and functions among neonates born to HBsAg⁺ /HBeAg⁺ mothers (HBeAg⁺ neonates), HBsAg⁺ /HBeAg^- mothers (HBeAg^- neonates) and healthy control mothers (HC neonates), using flow cytometry. The results showed that neonatal T cell phenotypes were similar regardless of HBeAg exposure. Upon anti-CD3 and anti-CD28 stimulation in HBeAg⁺ neonates, CD4⁺ T cell production of IFN-γ (P < .05) was significantly enhanced, while CD8⁺ T cells secreted significantly more IL-2 compared with those in HBeAg^- and HC groups (P < .05). Moreover, similar levels of IFN-γ and IL-10 were observed in the culture supernatant after stimulation with rHBsAg, rHBcAg or rHBeAg among HBeAg⁺ , HBeAg^- and HC neonates, whereas HBeAg⁺ neonates produced more TNF-α than HBeAg^- neonates upon stimulation with rHBcAg. In conclusion, the results indicated that the HBsAg⁺ /HBeAg⁺ maternal environment did not influence the phenotypes of cord blood T cells but boosted neonatal non-specific Th1-type cytokine production.

CON: All Patients With Immune-Tolerated Hepatitis B Virus Do Not Need to Be Treated

http://aasldpubs.onlinelibrary.wiley.com/hub/journal/10.1002/(ISSN)2046-2484/video/15-1-reading-attar a video presentation of this article.

Baseline Level of Hepatitis B Core Antibody Predicts Spontaneous Hepatitis B e Antigen (HBeAg) Seroconversion in HBeAg-Positive Children With a Normal Alanine Aminotransferase Level

It is not clear whether baseline hepatitis B core antibody (anti-HBc) level in hepatitis B e antigen (HBeAg)-positive children with a normal alanine aminotransferase (ALT) level is predictive of spontaneous HBeAg seroconversion. We investigated the correlation between anti-HBc level and the natural course of chronic hepatitis B (CHB) virus (HBV) infection in children, particularly the ability of baseline anti-HBc level to predict spontaneous HBeAg seroconversion during long-term follow-up. HBeAg-positive children with untreated CHB and a normal ALT level were followed longitudinally. Anti-HBc level was determined by double-sandwich immunoassay. Effects of anti-HBc levels and other parameters on spontaneous HBeAg seroconversion and the natural course of CHB were assessed. A total of 182 children (106 males) with a median age at enrollment of 10.6 years (interquartile range [IQR], 10.3-15.3) were followed for a median of 19.8 years (IQR, 11.9-21.9). Spontaneous HBeAg seroconversion occurred in 85 children (46.7%) during the follow-up. A baseline anti-HBc titer of >500 IU/mL (hazard ratio [HR] = 2.81), HBV genotype B and B + C (HR = 3.46), and a baseline hepatitis B surface antigen titer of ≤4.8 log₁₀  IU/mL (HR = 3.09) were predictive of spontaneous HBeAg seroconversion, based on multivariable survival analysis (P < 0.001). In cases remaining HBeAg positive, their anti-HBc levels increased gradually during follow-up because of ongoing inflammation. Conclusion: Baseline anti-HBc level is predictive of spontaneous HBeAg seroconversion in HBeAg-positive children with a normal ALT level. Anti-HBc level reflects anti-HBV immune response in the HBeAg-positive normal ALT phase of CHB.

Is hepatitis B antigen in cord blood an immunotolerogen playing a critical role in the pathogenesis of chronic hepatitis B?

Recently, we showed that infants with or without fetal hepatitis B e antigen (HBeAg) exposure had comparable antibody response to hepatitis B vaccination and proposed that fetal HBeAg exposure appears to not induce immunotolerance to HBV. Here, we summarized the different results on the topic of fetal HBeAg exposure in inducing immunotolerance to HBV nucleocapsid protein, and the evidence to back up that the tendency of high infection rate in infants of HBeAg-positive mothers is more likely associated with higher maternal viral loads and is less likely associated with the fetal HBeAg exposure. We consider that whether fetal HBeAg exposure plays an important role in the pathogenesis of chronic HBV infection remains to be an open question.

Is the function of the HBeAg really unknown?

The immune response to the hepatitis B virus (HBV) vaccine in newborns of hepatitis B e antigen (HBeAg)-positive or HBeAg-negative mothers is the subject of Huang et al. The authors report no correlation between the HBeAg status of the mothers/cord blood and the newborns immune response to the vaccine, but, unfortunately, draw unfounded conclusions regarding the tolerogenic potential of in utero exposure to HBeAg. In this reply, I address the possible influence of in utero exposure to the HBeAg, and briefly review other characteristics of the HBeAg, that may promote HBV chronicity. I argue that the function of HBeAg should no longer be considered "unknown" and that immunotolerance/immunomodulation represent the dominant functions of the HBeAg in viral-host interactions.

Comparison between chronic hepatitis B patients with untreated immune-tolerant phase vs. those with virological response by antivirals

Routine nucleos(t)ide analogs (NUCs) have not yet been recommended for patients with immune-tolerant (IT) phase in chronic hepatitis B virus (HBV) infection. We aimed to evaluate prognosis of patients in untreated IT-phase (UIT group), compared to those in immune-active phase who achieved virological response by NUCs according to guidelines (VR group). Between 2006 and 2012, patients in UIT or VR groups were included. Cumulative risks of HCC and liver-related events (LREs) development were assessed. Furthermore, propensity-score was calculated based upon age, gender, diabetes and liver stiffness. UIT group (n = 126) showed younger age, lower proportion of male gender and lower LS than VR group (n = 641). UIT group had similar 10-year cumulative risks of HCC (2.7% vs. 2.9%, p = 0.704) and LRE (4.6% vs. 6.1%, p = 0.903) development, compared to VR group. When we re-defined UIT group by the lower ALT cut-offs, 10-year cumulative risks of HCC and LRE development were 2.9% and 4.8%, respectively. Using propensity-score matching and inverse probability treatment weighting analysis, similar results were reproduced. UIT group consistently had similar prognosis compared to VR group. Therefore, further large-scale prospective studies in order to verify rationales of routine NUCs in UIT group are still required.

Hepatitis B core antigen regulates dendritic cell proliferation and apoptosis through regulation of PKC/NF‑κB signaling pathway

Hepatitis B core antigen (HBcAg) possesses unusual immunologic features. However, the biological roles and mechanisms of HBcAg in dendritic cell proliferation and apoptosis remain to be elucidated. In the present study, DC2.4 cells were treated with different concentrations of HBcAg (10, 20 and 30 µg/ml). MTT assay and flow cytometry (Annexin V/propidium iodide analysis) were performed to investigate changes in cell proliferation and apoptosis. Western blot analysis was conducted to examine the changes in nuclear factor (NF)‑κB and protein kinase C (PKC) signaling pathways. NF‑κB inhibitor pyrrolidine dithiocarbamate (PDTC) and PKC inhibitor Chelerythrine were used to block these two signaling pathways. It was identified that HBcAg increased proliferation and decreased apoptosis in a dose‑dependent manner. Western blotting results demonstrated that HBcAg upregulated p‑PKC, p‑IκB, p‑P65, tumor necrosis factor‑α and B‑cell lymphoma 2 (Bcl‑2) levels, and downregulated cleaved caspase 3, demonstrating that HBcAg activated the PKC and NF‑κB signaling pathways. NF‑κB inhibitor PDTC reduced the effects of HBcAg on DC2.4 proliferation (0.6 fold vs. 0.25 fold) and apoptosis (0.43 fold vs. 0.17 fold), and on Bcl‑2 expression levels. PKC inhibitor Chelerythrine reduced the biological effects of HBcAg; it reduced proliferation (0.67 fold vs. 0.23 fold) and upregulated apoptosis (0.43 fold vs. 0.13 fold). Chelerythrine also blocked NF‑κB activity and the HBcAg‑induced Bcl‑2 increase, suggesting the effect on Bcl‑2 from HBcAg was dependent on the PKC/NF‑κB signaling pathway. In conclusion, HBcAg promoted proliferation and inhibited apoptosis through the PKC/NF‑κB/Bcl‑2 signaling pathway in DC2.4 cells.

Immunomodulatory Function of HBeAg Related to Short-Sighted Evolution, Transmissibility, and Clinical Manifestation of Hepatitis B Virus

Hepatitis B virus (HBV) infection, a global public health problem can be asymptomatic, acute or chronic and can lead to serious consequences of infection, including cirrhosis, and hepatocellular carcinoma. HBV, a partially double stranded DNA virus, belongs to the family Hepadnaviridae, and replicates via reverse transcription of an RNA intermediate. This reverse transcription is catalyzed by a virus-encoded polymerase that lacks proof reading ability, which leads to sequence heterogeneity. HBV is classified into nine genotypes and at least 35 subgenotypes, which may be characterized by distinct geographical distributions. This HBV diversification and distinct geographical distribution has been proposed to be the result of the co-expansion of HBV with modern humans, after their out-of-Africa migration. HBeAg is a non-particulate protein of HBV that has immunomodulatory properties as a tolerogen that allows the virus to establish HBV infection in vivo. During the natural course of infection, there is seroconversion from a HBeAg-positive phase to a HBeAg-negative, anti-HBe-positive phase. During this seroconversion, there is loss of tolerance to infection and immune escape-HBeAg-negative mutants can be selected in response to the host immune response. The different genotypes and, in some cases, subgenotypes develop different mutations that can affect HBeAg expression at the transcriptional, translational and post-translational levels. The ability to develop mutations, affecting HBeAg expression, can influence the length of the HBeAg-positive phase, which is important in determining both the mode of transmission and the clinical course of HBV infection. Thus, the different genotypes/subgenotypes have evolved in such a way that they exhibit different modes of transmission and clinical manifestation of infection. Loss of HBeAg may be a sign of short-sighted evolution because there is loss of tolerogenic ability of HBeAg and HBeAg-negative virions are less transmissible. Depending on their ability to lead to HBeAg seroconversion, the genotype/subgenotypes exhibit varying degrees of short-sighted evolution. The “arms race” between HBV and the immune response to HBeAg is multifaceted and its elucidation intricate, with transmissibility and persistence being important for the survival of the virus. We attempt to shed some light on this complex interplay between host and virus.

Management of Pregnant Women and Children: Focusing on Preventing Mother-to-Infant Transmission

Hepatitis B virus (HBV) immunization has been effectively preventing chronic HBV infection with >90% efficacy in countries with universal neonatal immunization. Perinatal mother-to-infant transmission of HBV remains the major cause of chronic HBV infection despite immunization. Maternal hepatitis B e-antigen (HBeAg) and high viral load have been noted to be the most important risk factors for transmission. In recent years, short-term antiviral therapy for pregnant women in the third trimester has been shown to be highly effective in reducing 90% of vaccine failure in children. It is important to monitor maternal aminotransferase elevations postpartum. Long-term outcome of mothers and children is needed and awaits further investigations. Despite the above-mentioned preventive measures, it is also important to monitor high-risk children at 1 year of age with hepatitis B surface antigen and anti-hepatitis B to identify those with chronic HBV infection. Most of the children with chronic HBV infection were in the immune-tolerant phase. The goals for antiviral treatment in children are to reduce severity of liver injury, achieve HBeAg seroconversion, and prevent development of liver fibrosis and cancer. Studies on antiviral therapy are undergoing to elucidate the optimal indication and drug treatment for children. The ideal future goal of treatment is to eradicate chronic HBV infection globally.

Estimating age-related incidence of HBsAg seroclearance in chronic hepatitis B virus infections of China by using a dynamic compartmental model

The age-specific seroclearance pattern of hepatitis B surface antigen (HBsAg) in chronic hepatitis B virus (HBV) infections of China remains unclear. In this study, based on three national serosurvey data of hepatitis B in China, we propose an age- and time-dependent discrete model and use the method of non-linear least squares to estimate the age-specific annual rate of HBsAg seroclearance. We found that the HBsAg seroclearance in chronic HBV infections of China aged 1–59 years occurred at an average annual rate of 1.80% (95% CI, 1.54–2.06%) from 1993 to 2006. The HBsAg seroclearance occurred predominantly in the early childhood, 20–24 and 35–39 year age groups. Moreover, our model estimated that HBsAg seroclearance resulted in 23.38% of the decrease of total HBsAg prevalence for population aged 1–59 years in 2006. It also prevented 9.30% of new HBV infections (about 7.43 million people) and 9.95% of HBV-related deaths (about 0.25 million people) from 1993 to 2006. This study develops a new and efficient method to estimate the age-specific incidence of HBsAg seroclearance at a population-level and evaluate its effect.

A review of strategies to prevent mother-to-infant transmission of hepatitis B virus infection

Hepatitis B virus (HBV) infection causes long-term, life-threatening liver diseases worldwide. HBV is transmitted through either the horizontal or mother-to-infant route, which is the major route of transmission in endemic areas. Administration of hepatitis B immunoglobulin and hepatitis B vaccine to newborns of infected mothers prevents mother-to-infant transmission. Implementation of a universal hepatitis B vaccination program has proven successful in eliminating the infection and related complications. Nevertheless, efforts are still needed to improve global coverage of the hepatitis B vaccine. Infants born to highly viremic mothers are still at risk of infection despite current immunoprophylaxis. An increasing number of reports have shown promising efficacy and safety profiles with the use of nucleoside/nucleotide analogues in highly viremic pregnant women to prevent mother-to-infant transmission.

Potential Susceptibility Mutations in C Gene for Hepatitis B-Related Hepatocellular Carcinoma Identified by a Two-Stage Study in Qidong, China

A two stage study was conducted to explore new potential mutations in the full genome of hepatitis B virus (HBV) on the progression of hepatocellular carcinoma (HCC) in Qidong, China. In stage 1, full genomes of HBV were compared between 30 HCC cases and 30 controls. In stage 2, an independent case–control study including 100 HCC cases and 100 controls was enrolled to verify the relationship between hot-spot mutations and HCC development. Furthermore, a longitudinal study was conducted on 11 HCC cases with serial serum samples available before HCC diagnosis. A total of 10 mutations (including pre-S2 start codon mutation and pre-S deletion in pre-S gene, G1613A, C1653T, A1762T, and G1764A mutations in X gene, A2159G, A2189Y, G2203W, and C2288R mutations in C gene) showed an increased risk of HCC. In the validation study, pre-S deletion, C1653T, A1762T/G1764A, A2159G, A2189Y, G2203W, and C2288R mutations were associated with increased HCC risk in univariate analysis. Multivariate analysis indicated that pre-S deletion, A1762T/G1764A, A2159G, and A2189Y mutations were independently related with HCC development. Moreover, a significant biological gradient of HCC risk by number of mutations in the C gene was observed. Longitudinal observation demonstrated a gradual combination of the above mutations accumulated during the progression of HCC.

Hepatitis B virus and its sexually transmitted infection - an update

Epidemiology: incidence and prevalence: About 5% of the world’s population has chronic hepatitis B virus (HBV) infection, and nearly 25% of carriers develop chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). The prevalence of chronic HBV infection in human immunodeficiency virus (HIV)-infected individuals is 5%-15%; HIV/HBV coinfected individuals have a higher level of HBV replication, with higher rates of chronicity, reactivation, occult infection, and HCC than individuals with HBV only. The prevalence of HBV genotype A is significantly higher among men who have sex with men (MSM), compared with the rest of the population. Molecular mechanisms of infection, pathology, and symptomatology: HBV replication begins with entry into the hepatocyte. Sodium taurocholate cotransporting polypeptide was identified in 2012 as the entry receptor of HBV. Although chronic hepatitis B develops slowly, HIV/HBV coinfected individuals show more rapid progression to cirrhosis and HCC. Transmission and protection: The most common sources of HBV infection are body fluids. Hepatitis B (HB) vaccination is recommended for all children and adolescents, and all unvaccinated adults at risk for HBV infection (sexually active individuals such as MSM, individuals with occupational risk, and immunosuppressed individuals). Although HB vaccination can prevent clinical infections (hepatitis), it cannot prevent 100% of subclinical infections. Treatment and curability: The goal of treatment is reducing the risk of complications (cirrhosis and HCC). Pegylated interferon alfa and nucleos(t)ide analogues (NAs) are the current treatments for chronic HBV infection. NAs have improved the outcomes of patients with cirrhosis and HCC, and decreased the incidence of acute liver failure.

The clinical implications of hepatitis B virus genotypes and HBeAg in pediatrics

Although a successful vaccine against HBV has been implemented in 184 countries, eradication of hepatitis B virus (HBV) is still not on the horizon. There are over 240 million chronic carriers of HBV globally. The risk of developing chronic hepatitis ranges from >90% in newborns of hepatitis Be antigen (HBeAg)‐positive mothers, 25%–35% in children under 5 years of age and <5% in adults. HBeAg, a non‐particulate viral protein, is a marker of HBV replication. This is the only HBV antigen to cross the placenta, leading to specific unresponsiveness of helper T cells to the capsid protein and HBeAg in newborns. HBeAg is tolerated in utero and acts as a tolerogen after birth. Perinatal transmission is frequent when mothers are HBeAg‐positive, whereas it occurs less frequently when mothers are HBeAg‐negative. Sequence heterogeneity is a feature of HBV. Based on an intergroup divergence >7.5% across the complete genome, HBV is classified phylogenetically into at least nine genotypes. With between ~4% and 8% intergroup nucleotide divergence, genotypes A–D, F, H and I are classified further into subgenotypes. HBV genotypes/subgenotypes may have distinct geographical distribution and can develop different mutations in the regions of the HBV genome that code for HBeAg. These differences can be related to the role of HBV genotypes to the natural history of infection and mode of transmission. Thus genotypes/subgenotypes of HBV can be responsible for the different natural history of infection and modes of transmission in children, found in various regions of the world, where different genotypes/subgenotypes prevail. Copyright © 2016 John Wiley & Sons, Ltd.

Current views and advances on Paediatric Virology: An update for paediatric trainees

Paediatric Virology is a bold new scientific field, which combines Paediatrics with Virology, Epidemiology, Molecular Medicine, Evidence-based Medicine, Clinical Governance, Quality Improvement, Pharmacology and Immunology. The Workshop on Paediatric Virology, which took place on Saturday October 10, 2015 in Athens, Greece, provided an overview of recent views and advances on viral infections occurring in neonates and children. It was included in the official programme of the 20th World Congress on Advances in Oncology and the 18th International Symposium on Molecular Medicine, which attracted over 500 delegates from the five continents. During the Workshop, the topics covered included the challenges of vaccine implementation against human papillomaviruses in countries under financial crisis, strategies for eradicating poliomyelitis and its 60th vaccine anniversary, as well as the debate on the association between autism and vaccination against measles, mumps and rubella. Among the non-vaccine related topics, emphasis was given to viral infections in prematurely born infants and their long-term outcomes, new paediatric intensive care management options for bronchiolitis related to respiratory syncytial virus, the clinical implications of hepatitis B virus and cytomegalovirus genotyping, the Ebola virus threat and preparedness in Paediatric Emergency Departments, oral, oropharynx, laryngeal, nasal and ocular viral infections and Merkel cell polyomavirus as a novel emerging virus of infancy and childhood. In this review, we provide selected presentations and reports discussed at the Workshop.

The independent impact of newborn hepatitis B vaccination on reducing HBV prevalence in China, 1992-2006: A mathematical model analysis

OBJECTIVE

To evaluate the independent impact of newborn hepatitis B vaccination on reducing HBV prevalence in China, from its introduction in 1992 to 2006.

METHODS

An age- and time-dependent discrete dynamic model was developed to simulate HBV transmission in China under the assumptions of no any change in interventions and only with newborn vaccination introduction, respectively. The initial conditions of the model were determined according to the national serosurvey in 1992. The simulated results were compared with the observed results of the national serosurvey in 2006, and the contribution rate of newborn vaccination on reducing HBV prevalence was calculated overall and by birth cohort.

RESULTS

The total HBV prevalence would remain stable through the 14-year period if no any change in interventions, but decrease year by year if only with newborn vaccination introduction. Newborn vaccination could account for more than 50% of the reduction of the total HBV prevalence, although the full 3-dose and timely birth dose vaccination coverage rates were low in the early years. The results by birth cohort showed that the higher the two coverage rates, the higher contribution rate on reducing HBV prevalence. For the 2005 birth cohort which had high levels in the two coverage rates, the contribution rate could reach more than 95%.

CONCLUSION

Newborn hepatitis B vaccination from 1992 to 2006 in China had played the most important role in reducing HBV prevalence. Newborn vaccination with high full 3-dose and timely birth dose coverage rates is the decisive factor in controlling hepatitis B in China.

Is mother-to-infant transmission the most important factor for persistent HBV infection?

Of the infants born to hepatitis B surface antigen (HBsAg)-positive mothers globally, 42.1% who did not receive hepatitis B virus (HBV) passive-active immunoprophylaxis and 2.9% of infants who received the immunoprophylaxis acquired HBV infection perinatally. Moreover, perinatal infection occurred in 84.2% (18.8%-100%) and 8.7% (0.0-21.0%) of infants born to hepatitis B e-antigen (HBeAg)-positive mothers who did not and did receive immunoprophylaxis, respectively; by contrast, the infection rates were 6.7% (0.0-15.4%) and 0.4% (0.0-2.5%) for infants born to HBeAg-negative-carrier mothers, respectively. The chronicity rates of HBV infection acquired perinatally were 28.2% (17.4%-33.9%) in infants born to HBeAg-negative mothers and 64.5% (53.5%-100%) in infants born to HBeAg-positive mothers. HBV mother-to-child transmission was more frequent in East Asia relative to other areas. In addition to differences in the endemic HBV genotype, the interchange of allelic dominance in genetic polymorphisms in HLA class II and NF-κB between the Chinese and European populations may explain why chronic HBV infection frequently affects the Chinese. The risk of progressing into chronic infection was inversely related to the age of children at the time of horizontal transmission. To further diminish HBV chronic infection, it is necessary to enforce antiviral treatment after the 28th week of gestation for HBeAg-positive mothers and to improve the health habits of carrier mothers and household sanitary conditions.

Infantile hepatitis B in immunized children: risk for fulminant hepatitis and long-term outcomes

BACKGROUND

Infantile hepatitis B after neonatal immunoprophylaxis is a rare yet distinct disease. This study aimed to analyze the long-term outcomes and risk factors in immunized infants with hepatitis B.

METHODS

The clinical parameters and outcomes of 41 infants born after universal immunization, and admitted for HBV-positive hepatitis were studied. All patients were followed for at least 6 months (median  = 4.4 years, range 0.6-18.1 years). Patient survival, changes of HBsAg and HBeAg status, and complications were analyzed.

RESULTS

Among the 41 cases (32 males, 9 females), 21 presented with fulminant hepatitis (FH), and 20 with non-fulminant hepatitis (NFH). Ninety-five percent (36/38) of the mothers were positive for hepatitis B surface antigen (HBsAg). Multivariate analyses revealed younger age of onset (age <7 months) and negative maternal hepatitis B e antigen (HBeAg) were associated with FH (p = 0.03 and p = 0.01, respectively). An infantile fulminant hepatitis B risk score using maternal/infant HBeAg positivity and onset age was proposed. Among the FH cases, the rate of mortality, HBsAg clearance, and chronic HBV infection were 47.6%, 38.1%, and 14.3%, respectively. Among the NFH cases, 35% developed chronic infection. Of the 9 chronically infected children received long-term follow-up, 8 had HBeAg seroconversion before 4 years of age. One case of FH developed hepatocellular carcinoma 14 years later.

CONCLUSIONS

Maternal HBsAg + /HBeAg- and early onset age were risk factors for FH in immunized infants. A significant portion of patients with FH or NFH evolve to chronic HBV infection, with HBeAg seroconversion in young childhood. Close surveillance for hepatocellular carcinoma is warranted in patients surviving infantile hepatitis B.

Prevention of hepatitis B virus infection and liver cancer

Hepatocellular carcinoma (HCC) is one of the five leading causes of cancer death in human. Hepatitis B virus (HBV) is the most common etiologic agent of HCC in the world, particularly in areas prevalent for HBV infection such as Asia, Africa, southern part of Eastern and Central Europe, and the Middle East. Risk factors of HBV-related HCC include (1) viral factors-persistent high viral replication, HBV genotype C or D, pre-S2 or core promoter mutants; (2) host factors-older age (>40 years old) at HBeAg seroconversion, male gender; (3) mother-to-infant transmission; and (4) other carcinogenic factors-smoking, habitual use of alcohol, etc. Prevention is the best way to control cancer. There are three levels of liver cancer prevention, i.e., primary prevention by HBV vaccination targeting the general population, secondary prevention by antiviral agent for high-risk subjects with chronic HBV infection, and tertiary prevention by antiviral agent to prevent recurrence for patients who have been successfully treated for liver cancer. Primary prevention by hepatitis B vaccination is most cost effective. Its cancer preventive efficacy supports it as the first successful example of cancer preventive vaccine in human. This experience can be extended to the development of other cancer preventive vaccine. Careful basic and clinical research is needed to develop ideal vaccines to induce adequate protection. Understanding the main transmission route and age at primary infection may help to set the optimal target age to start a new cancer preventive vaccination program. Besides timely HBV vaccination, the earlier administration of hepatitis B immunoglobulin immediately after birth, and even antiviral agent during the third trimester of pregnancy to block mother-to-infant transmission of HBV are possible strategies to enhance the prevention efficacy of HBV infection and its related liver cancer.

The epidemiology of hepatitis B virus infection in HIV-infected and HIV-uninfected pregnant women in the Western Cape, South Africa

OBJECTIVES

Persistent hepatitis B virus (HBV) infection is a major cause of morbidity and mortality in sub-Saharan Africa. The HIV epidemic has the potential to affect its biology. Immunisation protocols established in the pre-HIV era are based upon data showing predominantly horizontal infant transmission. This study aimed to determine whether HIV co-infection will change the epidemiology of HBV both by increasing infectivity and by favouring the escape of viruses bearing phenotypically altered HBsAg.

METHODS

This retrospective cross-sectional study used antenatal samples from the 2008 Antenatal Sentinel HIV and Syphilis Prevalence Survey in the Western Cape, South Africa. All HIV-infected women were age and race-matched to HIV-uninfected women. Samples were tested for serological markers of HBV and HDV infection. HBV viral load, consensus sequencing and genotyping were performed. Luminex technology was used to determine HBsAg phenotype. All samples from HIV-infected women were tested for traces of antiretroviral drugs by mass spectrometry.

RESULTS

This study showed a trend toward loss of immune control of HBV in HIV-infected women with 3.4% of samples containing HBsAg, 18.9% contained HBeAg. In contrast, 2.9% of samples from HIV-uninfected women contained HBsAg and 17.1% of these HBeAg. The median HBV load in the HIV-infected group was 9.72×10(7)IU/ml and in the HIV-uninfected group 1.19×10(6)IU/ml. Genotyping showed 63/68 samples belonged to genotype A and the remainder genotype D. Mutations in the precore region were found in 35% and 33% of samples from HIV-infected and HIV-uninfected respectively. Although no major epitope ablation was found, marked variation in HBsAg profiles in HIV-infected group was demonstrated. No HDV infection was detected.

CONCLUSION

HIV-HBV co-infected women exhibit a degree of immune escape. One in six HBV-infected pregnant women, irrespective of HIV status is HBeAg seropositive. HBV immunization of newborns in sub-Saharan Africa should be implemented.

Is hepatitis B virus transmitted via the male germ line? A seroepidemiological study in fetuses

OBJECTIVES

To detect father-to-fetus transmission of hepatitis B virus (HBV) in utero.

METHODS

We conducted a study at the prenatal diagnosis center of Taizhou City. Fetuses with one or both parents carrying the hepatitis B surface antigen (HBsAg) were identified before genetic testing during the period 2008-2010. Intrauterine samples were obtained by amniocentesis or cordocentesis and tested for serological markers and by quantitative DNA assays. All neonates received combined hepatitis B immunoprophylaxis after delivery, and serological follow-up tests were performed at 1 year of age.

RESULTS

Of the 407 couples enrolled in the study, HBV was carried by fathers only in 164, and none of their fetuses were found to be HBV DNA-positive in utero. All fetal serological markers were found to be of maternal but not paternal origin. The response rate to postnatal vaccination was 98.6%, and none of the children who failed immunoprophylaxis were the offspring of the HBV carrier fathers.

CONCLUSIONS

The infection of fetuses with HBV from the spermatozoa of carrier fathers seems unlikely, especially in an area where pre-conception hepatitis B vaccination is routinely provided.

HBeAg seroconversion in children infected during early childhood with hepatitis B virus

BACKGROUND

Seroconversion of hepatitis B e-antigen (HBeAg) to anti-HBe is associated with lower viral load and liver diseases.

OBJECTIVES

The purpose of this study was to assess the seroconversion rate of HBeAg to anti-HBe in children who acquired hepatitis B virus (HBV) infection during early childhood.

STUDY DESIGN

From September 1990 to December 2010, 139 HBeAg-positive children were followed up. Eighty-one subjects were of failure of hepatitis B immune globulin (HBIG) and hepatitis B vaccine at birth and 58 children <10 years of age who were born before 1990 did not receive HBIG and hepatitis B vaccine. HBsAg, HBeAg, anti-HBs and anti-HBe were assessed every 6 months.

RESULTS

Sixty-two (44.6%) cases were males and 77 (55.4%) were females. The mean duration of follow-up was 18 ± 6.6 years. Twenty-four (17.3%) mothers were HBeAg positive and 115 (82.7%) were anti-HBe positive. Eighty-two (59%) children became anti-HBe positive. The seroconversion rates in the first, second and third decades were 25%, 63.4% and 70.5%, respectively (p<0.001). The children of anti-HBe-positive mothers had a higher seroconversion rate than the HBeAg-positive mothers (75% vs. 33.9%, p<0.0001). Time to seroconversion in children born to HBeAg-positive mothers was similar to those born to anti-HBe positive mothers (hazard ratio (HR)=1.03, p=0.973). Time to seroconversion in children who received hepatitis B vaccine and HBIG was shorter than those who did not (HR=6.35, p<0001).

CONCLUSIONS

HBeAg seroconversion in the second and the third decades was higher than that in the first decade. Children born to anti-HBeAg-positive mothers and those who received HBIG and hepatitis B vaccine had higher seroconversion rates.

Suppression of furin by interferon-γ and the impact on hepatitis B virus antigen biosynthesis in human hepatocytes

The roles of furin and intrahepatic cytokines in chronic heptatitis B virus (HBV) infection remain largely unknown. Here, we examined the relations between furin, IL-10, IL-12β, interferon (IFN)-γ, programed death (PD)-1, programed death ligand (PD-L)1, and the suppression of hepatitis B e antigen (HBeAg) and surface antigen (HBsAg) biosynthesis. Liver biopsies were performed on 20 chronically HBV-infected (15 HBeAg-positive and 5 HBeAg-negative) patients to assess liver inflammation/fibrosis, and mRNA levels of furin, IL-10, IL-12β, IFN-γ, PD-1, and PD-L1 were assessed by quantitative real-time PCR. IFN-γ mRNA abundance was associated with lower furin mRNA levels and higher PD-1 and PD-L1 mRNA levels in liver tissue from HBeAg-positive patients. IL-10 and IL-12β mRNA levels positively correlated with IFN-γ expression levels (P < 0.05). PD-L1 and furin mRNA levels were further assessed in IFN-γ-stimulated hepatoma cell lines with (HepG2.2.15 cells) and without (HepG2 and Huh7 cells) HBV replication. IFN-γ enhanced PD-L1 expression in hepatoma cells. In HepG2.2.15 cells, IFN-γ further suppressed furin and HBeAg expression. Furin inhibition and knockdown in HepG2.2.15 cells also down-regulated HBeAg and HBsAg biosynthesis. These data suggest that IFN-γ modulates the inflammatory response to avoid excessive hepatocyte damage through the enhancement of PD-1/PD-L1 expression, whereas furin suppression may contribute to a reduction in HBeAg/HBsAg biosynthesis.

HBV genotypes: relevance to natural history, pathogenesis and treatment of chronic hepatitis B

Although chronic HBV infection is the leading cause of chronic liver disease and death worldwide, there are substantial differences in its clinical courses regarding prevalence, mode of transmission, characteristics of each phase, responses to antiviral therapy, and development of cirrhosis and hepatocellular carcinoma, according to geographical areas (Asia versus Western Europe and North America versus Africa). Furthermore, the clinical course in infected individuals depends on a complex interplay among various factors including viral, host, environmental and other factors. Recently, understanding of molecular characteristics of the prevailing HBV genotypes, frequently accompanied mutations and their clinical implications might explain these geographical differences more pertinently. Hence, in this article, we review the global epidemiology and the natural history of HBV infection, with emphasis on summarizing the different HBV genotypes according to regions.

Effects of maternal screening and universal immunization to prevent mother-to-infant transmission of HBV

BACKGROUND & AIMS

Mother-to-infant transmission is the major cause of hepatitis B virus (HBV) infection among immunized children. There has been much debate about screening pregnant women and administering hepatitis B immunoglobulin (HBIG) to newborns. We analyzed the rate of HBV infection among children born to hepatitis B surface antigen (HBsAg)-positive mothers and whether HBIG administration reduces transmission.

METHODS

We analyzed data from 2356 children born to HBsAg-positive mothers, identified through prenatal maternal screens. In addition to HBV vaccines, HBIG was given to all 583 children with hepatitis B e antigen (HBeAg)-positive mothers and to 723 of 1773 children with HBeAg-negative mothers. Serology tests for HBV were performed from 2007 to 2009, when children were 0.5-10 years old.

RESULTS

A significantly greater percentage of children with HBeAg-positive mothers tested positive for antibodies against the hepatitis B core protein (16.76%) and HBsAg (9.26%) than children with HBeAg-negative mothers (1.58% and 0.29%, respectively; P < .0001 and <.001). Among the HBV-infected children, the rate of chronicity also was higher among children with HBeAg-positive mothers than children with HBeAg-negative mothers (54% vs 17%; P = .002). Similar rates of antibodies against the hepatitis B core protein (0.99% and 1.88%; P = .19) and HBsAg (0.14% and 0.29%; P = .65) were noted in children born to HBeAg-negative mothers who were or were not given HBIG. Infantile fulminant hepatitis developed in 1 of 1050 children who did not receive HBIG (.095%).

CONCLUSIONS

Children born to HBeAg-positive mothers are at greatest risk for chronic HBV infection (9.26%), despite immunization. Administration of HBIG to infants born to HBeAg-negative mothers did not appear to reduce the rate of chronic HBV infection, but might prevent infantile fulminant hepatitis. Screening pregnant women for HBsAg and HBeAg might control mother-to-infant transmission of HBV.

Dynamics of HBV cccDNA expression and transcription in different cell growth phase

Background

The covalently closed-circular DNA (cccDNA) of hepatitis B virus (HBV) is associated with viral persistence in HBV-infected hepatocytes. However, the regulation of cccDNA and its transcription in the host cells at different growth stages is not well understood.

Methods

We took advantages of a stably HBV-producing cell line, 1.3ES2, and examine the dynamic changes of HBV cccDNA, viral transcripts, and viral replication intermediates in different cellular growth stages.

Results

In this study, we showed that cccDNA increased suddenly in the initial proliferation phase of cell growth, probably attributable to its nuclear replenishment by intracellular nucleocapsids. The amount of cccDNA then decreased dramatically in the cells during their exponential proliferation similar to the loss of extrachromosomal plasmid DNA during cell division, after which it accumulated gradually while the host cells grew to confluency. We found that cccDNA was reduced in dividing cells and could be removed when proliferating cells were subjected to long term of lamivudine (3TC) treatment. The amounts of viral replicative intermediates were rapidly reduced in these proliferating cells and were significantly increased after cells reaching confluency. The expression levels of viral transcripts were increased in parallel with the elevated expression of hepatic transcription factors (HNF4α, CEBPα, PPARα, etc.) during cell growth confluency. The HBV transcripts were transcribed from both integrated viral genome and cccDNA, however the transcriptional abilities of cccDNA was less efficient then that from integrated viral genome in all cell growth stages. We also noted increases in the accumulation of intracellular viral particles and the secretion of mature virions as the cells reached confluency and ceased to grow.

Conclusions

Based on the dynamics of HBV replication, we propose that HBV replication is modulated differently in the different stages of cell growth, and can be divided into three phases (initial proliferation phase, exponential proliferation phase and growth confluency phase) according to the cell growth curve. The regulation of cccDNA in different cell growth phase and its importance regarding HBV replication are discussed.

Long-term effect of maternal HBeAg on delayed HBeAg seroconversion in offspring with chronic hepatitis B infection

BACKGROUND AND AIMS

This cohort study investigated the long-term effect of maternal hepatitis B virus (HBV) sero-status on the spontaneous HBeAg seroconversion in offspring with chronic HBV infection.

METHODS

A total of 185 HBeAg-positive chronic HBV-infected children, with maternal HBV seromarkers checked, were enrolled. The median age at enrolment and follow-up duration was 5.7 years (range, neonate to 16.5 years) and 20.2 years (range, 4.2-31.0 years) respectively. These children were grouped according to the initial maternal HBsAg and HBeAg status: (i) children of non-carrier mothers (n=48); (ii) children of HBeAg-negative chronic HBV-infected mothers (n=57); (iii) children of HBeAg-positive chronic HBV-infected mothers (n=80). HBV seromarkers and liver function profiles of these children were performed at 6-month intervals.

RESULTS

One hundred and twenty-one (65.4%) subjects had achieved spontaneous HBeAg seroconversion at the end of this follow-up study. Spontaneous HBeAg seroconversion was achieved in 83.3% of children with non-carrier mothers, 73.7% of children with HBeAg-negative chronic HBV-infected mothers and 48.8% of children with HBeAg-positive mothers during similar duration (P<0.001). Positive maternal HBeAg and genotype C were associated with delayed spontaneous HBeAg seroconversion in multivariate analysis (P=0.01 and P=0.002 respectively). In children of HBeAg-positive chronic HBV-infected mothers, persistent presence of maternal HBeAg showed a trend of association with delayed HBeAg seroconversion in their offspring (P=0.06). Children of late maternal HBeAg seroconversion (>40 years old) had delayed HBeAg seroconversion compared with those of early HBeAg seroconversion mothers (P=0.06).

CONCLUSIONS

Persistence of maternal HBeAg is an important risk factor for delayed spontaneous HBeAg seroconversion in children with chronic HBV infection.

Natural history of hepatitis B virus infection: pediatric perspective

Hepatitis B virus (HBV) infection is an important disease globally. Chronic HBV infection may result in serious complications. Its transmission may be either perinatal or horizontal. Perinatal transmission is particularly important after the implementation of a universal vaccination program. Through either route, chronic carrier status is usually established in early childhood. The course of the disease course is determined by the host-virus interaction. The host's immune system initially tolerates the virus, and then gradually attempts to clear it. The virus, on the other hand, tries to avoid host immune system attack by a strategy involving targeted epitope mutations. By generating mutants, the virus can survive attacks from the host's immune system, enabling the infection to persist. Different individuals have different responses to HBV infection; genetic polymorphisms in cytokines, hormones, and other immune modulators may affect the final outcome of chronic HBV infection. Due to the implementation of a universal infant HBV vaccination program, HBV infection is now under control. Unfortunately, there still are some cases of vaccination failure. Very high maternal viremia, in utero infection, or escape mutants are possible reasons for vaccination failure. Immunocompromised hosts also risk vaccination failure. Blood or organ donors with occult HBV infection are possible sources for immunocompromised hosts. These victims of vaccination failure may exhibit a different disease course due to chronic HBV infection from those who acquired the infection before the universal vaccination era. The achievement of our ultimate goal of HBV elimination depends on a globally effective universal vaccination program, as well as the application of some novel successful medications to control those who are already infected.

Tumour necrosis factor-α promoter region polymorphisms affect the course of spontaneous HBsAg clearance

BACKGROUND

This study aimed to investigate the roles of tumour necrosis factor-α (TNF-α) gene polymorphisms in the spontaneous clearance of HBsAg after a hepatitis B virus (HBV) infection.

METHODS

Polymorphisms in the TNF-α (-1031 T to C, -863 C to A, -857 C to T, -308 G to A and -238 G to A transition) gene were evaluated in 274 chronic HBV-infected patients and 194 patients with resolved HBV infection. The peripheral blood mononuclear cells (PBMC) isolated from 77 (28%) of the 274 chronic HBV-infected patients with negative HBeAg and positive antibody to HBeAg were stimulated with HBcAg. Data on TNF-α genotypes and phenotypes in subjects with/without the A allele at the TNF-α-863 promoter single nucleotide polymorphism (rs1800630) were compared.

RESULTS

The A allele in the -863 promoter region of the TNF-α gene was present in 154 (56.2%) chronic HBV-infected patients and 87 (44.8%) patients who recovered from HBV infection (odds ratio 1.58; P<0.01). The TNF-α-863 A allele genotype predicted lower TNF-α production by PBMC after in vitro HBcAg stimulation (P<0.02).

CONCLUSIONS

The A allele at the -863 locus of the promoter region of the TNF-α gene predicts lower HBcAg-inducible TNF-α secretion. It is also associated with chronicity of HBV infection.

Does hepatitis B virus prenatal transmission result in postnatal immunoprophylaxis failure?

The objective of this work was to evaluate whether postnatal hepatitis B immunization failure in children is caused by prenatal infections. A prospective study was conducted from October 2006 to September 2008. Fetal samples from HBsAg-positive mothers were retrieved by either amniocentesis or cordocentesis (percutaneous umbilical blood sampling [PUBS]). Hepatitis B virus (HBV) serologic markers (HBVM) and quantitative HBV DNA assays were performed to assess prenatal infection. All neonates were given combined HBV immunoprophylaxis after delivery. The newborns were followed up with HBV serologic testing at 1 year old. For the 252 pregnant women recruited, 16 fetuses were found to be HBV DNA positive, with all HBV DNA levels under 10(4) copies/ml. HBsAg and HBV DNA detected in the uterus were uncommon and were expressed at low levels. In contract to the case with prenatal statuses, neonatal serologies were more similar to their mothers'. The response rate of vaccination was 95%. Six children for whom immunoprophylaxis failed were born to HBeAg-positive mothers with high HBV DNA levels (>10(8) copies/ml), but only one of them was found to be positive for intrauterine HBV DNA (8.5 × 10(2) copies/ml). The presence of intrauterine hepatitis B antigen and DNA does not indicate postnatal HBV infection and vaccination failure.

HEPATITIS B AND PREGNANCY, THE SCIENTIFIC BASIS FOR PERINATAL PREVENTION

Hepatitis B and its complications are one of the major global health problems. Around 2 billion individuals are infected by hepatitis B virus (HBV) worldwide, more than 350 million are chronically infected, and approximately 15 to 40 percents of them will develop serious complications such as liver cirrhosis, hepatic failure, or hepatocellular carcinoma (HCC). The worldwide prevalence of chronic HBV infection ranges from 0.1 to 20 percent and varies widely in different geographic areas. According to the prevalence rate, WHO has classified countries into 3 levels: high areas (>8%) such as Africa, Asia, Western Pacific and Middle East; intermediate areas (2–8%) such as South America and Eastern Europe, and low areas (<2%) such as Western Europe, North America, and Australia.

Management of chronic hepatitis B in children

Hepatitis B virus (HBV) infection is a worldwide problem and can cause acute liver failure, acute hepatitis, chronic hepatitis, liver cirrhosis, and liver cancer. In areas of high prevalence such as in Asia, Africa, southern Europe, and Latin America, the hepatitis B surface antigen positive rate ranges from 2% to 20%.In endemic areas, HBV infection occurs mainly during infancy and early childhood. Mother-to-infant transmission accounts for approximately half of the chronic HBV infections. In contrast to infection in adults, HBV infection during early childhood results in a much higher rate of persistent infection and long-term serious complications such as liver cirrhosis and HCC.Three phases of chronic hepatitis B have been identified: the immune-tolerant phase, the immune-active phase, and the inactive hepatitis B phase. These phases of infection are characterized by variations in viral replication, hepatic inflammation, spontaneous clearance, and response to antiviral therapy.The optimal goal of antiviral therapy for chronic HBV infection is to eradicate HBV and to prevent its related liver complications. However, due to the limited effect of available therapies in viral eradication, the goal of treatment is to reduce viral replication, to minimize liver injury, and to reduce infectivity. In this review the current recommendations for monitoring and treating chronic HBV infection in children are reviewed.

HBV infection in indigenous children, 20 years after immunization in Taiwan: a community-based study

OBJECTIVES

Hepatitis B virus infection is hyperendemic in Taiwan. In the past, the infection rate has been higher in indigenous villages. The prevalence of chronic HBV infection among indigenous children after immunization remains unknown.

METHODS

A total of 843 indigenous children were checked for the hepatitis B seromarker. Another 606 metropolitan children were enrolled for comparison in 2005.

RESULTS

The seroprevalences (%) of HBsAg, (hepatitis B surface antigen) anti-HBs, (antibody to hepatitis B surface antigen) and anti-HBc (antibody to hepatitis B core antigen) among indigenous and metropolitan children were 3.2 vs. 0.17 (p<0.001), 47.4 vs. 51.2 (p=0.164), and 10.7 vs. 1.7 (p<0.001), respectively. Among the indigenous children, who were divided into three age groups, the prevalences of HBsAg and anti-HBc increased with age, while anti-HBs decreased significantly (p=0.025, 0.002, and <0.001, respectively). Children with positive HBsAg had a significantly higher mean (SD) age (10.2 (2.2) vs. 9.2 (2.1) years, p=0.024) and a higher ALT value (16.4 (8.0) vs. 10.6 (8.3) IU/L, p=0.001). In a multivariable analysis, indigenous residency, older age group and abnormal ALT value were independent factors associated with positive HBsAg.

CONCLUSIONS

The seroprevalence of hepatitis B infection has obviously declined among indigenous children 20 years after mass immunization programs launched in Taiwan. However, it is still higher than that of metropolitan children. Higher rates of chronic HBV infection in the mothers might be one important explanation for this finding.

Mutations of T-cell epitopes in the hepatitis B virus surface gene in children with chronic infection and hepatocellular carcinoma

BACKGROUND AND OBJECTIVES

Hepatitis B virus (HBV) infection induces an interaction of host immune responses against virus antigen-presenting hepatocytes. The emergence of mutants is a strategy through which the virus can escape host attacks and produce chronic infection. In this study, we aimed to investigate mutations of the human leukocyte antigen-A2-restricted T-cell epitope (TCE) in chronic HBV-infected children.

METHODS

In total, 441 chronic HBV-infected children were longitudinally followed-up every 6 months. They were divided into hepatitis B e antigen (HBeAg) (-) (N = 60) and HBeAg (+) (N = 381) groups according to this seromarker at their enrollment. The HBeAg (+) group was further divided into HBeAg (+/-) (N = 229) and HBeAg (+/+) (N = 152) groups, depending on the occurrence of spontaneous HBeAg seroconversion. Twenty-five children with HBV-related hepatocellular carcinoma (HCC) were also recruited. TCE mutations were examined using the latest serum samples, and serum samples at enrollment were used if TCE mutations were present in the latest serum samples in the seroconverters. HBV genotypes and liver enzymes were also analyzed.

RESULTS

The HBeAg (+/+) group had a lower TCE mutation rate (7.9%) than that of the HBeAg (+/-) (29.2%), HBeAg (-) (26.7%), and HCC (28.0%) groups. In the HBeAg (+/-) group, TCE mutations were present before HBeAg seroconversion in 11.9% of the subjects. Those with TCE mutations showed HBeAg seroconversion at an older age (16.1 +/- 5.3 yr vs 12.7 +/- 5.7 yr, P < 0.001) and with higher peak alanine aminotransferase (ALT) levels (median 175 U/L vs 119 U/L, P = 0.03) than those without TCE mutations.

CONCLUSIONS

TCE mutations tended to be positively associated with HBeAg seroconversion and higher ALT levels in chronic HBV-infected children.

Natural history and clinical management of chronic hepatitis B virus infection in children

Hepatitis B virus (HBV) infection may cause acute, fulminant, or chronic hepatitis, leading to liver cirrhosis or hepatocellular carcinoma. Despite the availability of effective vaccine, HBV infection during infancy or early childhood is common in areas of high endemicity. In these regions, mother-to-infant transmission accounts for approximately 50% of chronic infections. Although the natural history of HBV infection in adults is well characterized, little information is available in the literature regarding the natural history of HBV infection in children. Similar to infection in adults, chronic HBV infection in children can be divided into distinct phases: immune tolerant, immune clearance, and inactive carrier state. However, acute exacerbation, with reactivation of HBV replication and re-elevation of alanine aminotransferase levels after hepatitis B e antigen seroconversion, is relatively rare in children, in comparison to adults. Although several potent antiviral agents are now available for the treatment of chronic hepatitis B, experience with these agents in the pediatric setting is limited. To date, conventional interferon alpha and lamivudine are the only two antiviral agents approved to treat chronic hepatitis B in children. The rapid emergence of resistant HBV associated with long-term lamivudine therapy, as well as poor tolerability associated with conventional interferon alpha, are factors that should be considered before initiating antiviral therapy. This article reviews current knowledge regarding the natural history and treatment of chronic hepatitis B in children. Factors that affect the natural history of HBV infection in children are also reviewed.

Natural history of hepatitis B virus infection: an update for clinicians

Hepatitis B virus (HBV) is a common viral pathogen that causes a substantial health burden worldwide. Significant progress has been made in the past few decades in understanding the natural history of HBV infection. A dynamic balance between viral replication and host immune response is pivotal to the pathogenesis of liver disease. In immunocompetent adults, most HBV infections spontaneously resolve, whereas in most neonates and infants they become chronic. Those with chronic HBV may present in 1 of 4 phases of infection: (1) in a state of immune tolerance, (2) with hepatitis B e antigen (HBeAg)positive chronic hepatitis, (3) as an inactive hepatitis B surface antigen carrier, or (4) with HBeAg-negative chronic hepatitis. Of these, HBeAg-positive and HBeAg-negative chronic hepatitis may progress to cirrhosis and its long-term sequelae including hepatic decompensation and hepatocellular carcinoma. Several prognostic factors, such as serum HBV DNA concentrations, HBeAg status, serum aminotransferases, and certain HBV genotypes, have been identified to predict long-term outcome. These data emphasize the importance of monitoring all patients with chronic HBV infection to identify candidates for and select optimal timing of antiviral treatment, to recognize those at risk of complications, and to implement surveillance for early detection of hepatocellular carcinoma.