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

Navigating Perinatal Challenges: A Comprehensive Review of Hepatitis B Viral Infection and Pregnancy Outcomes

Hepatitis B viral infection poses a significant challenge during pregnancy, as the risk of vertical transmission carries serious consequences for both maternal and neonatal well-being. This comprehensive review delves into the intricacies surrounding hepatitis B infection during the perinatal period, shedding light on its impact on pregnancy outcomes and stressing the necessity of addressing it within the broader framework of perinatal care. By scrutinizing current evidence, diagnostic methodologies, management techniques, and preventive measures, this review emphasizes the urgent need for enhanced screening protocols, timely interventions, and augmented public health initiatives. Notably, key findings underscore the elevated likelihood of chronic hepatitis B virus (HBV) infection in infants and its enduring implications for the health of both mothers and newborns. The imperative call to action advocates for a multifaceted approach, engaging healthcare professionals, policymakers, and public health agencies to optimize strategies for management and prevention, thereby striving for improved outcomes for pregnant women and their infants affected by hepatitis B viral infection.

Solely HBsAg intrauterine exposure accelerates HBV clearance by promoting HBs-specific immune response in the mouse pups

Chronic hepatitis B virus (HBV) infection due to perinatal mother-to-infant transmission (MTIT) remains a serious global public health problem. It has been shown that intrauterine exposure to HBV antigens might account for the MTIT-related chronic infection. However, whether hepatitis B surface antigen (HBsAg) intrauterine exposure affected the offspring’s immune response against HBV and MTIT of HBV has not been fully clarified. In this study, we investigated the effects and the potential mechanisms of the HBsAg intrauterine exposure on the persistence of HBV replication using a solely HBsAg intrauterine exposure mice model. Our results revealed that solely HBsAg intrauterine exposure significantly accelerated the clearance of HBV when these mice were hydrodynamically injected with pBB4.5-HBV1.2 plasmids after birth, which may be due to the increased number of HBs-specific CD8⁺ T cells and interferon-gamma secretion in the liver of mice. Mechanismly, HBsAg intrauterine exposure activated antigen-presenting dendritic cells, which led to the generation of antigen-specific cellular immunological memory. Our data provide an important experimental evidence for the activation of neonatal immune response by HBsAg intrauterine exposure.

Tenofovir alafenamide in blocking mother-to-child transmission of hepatitis B virus: a multi-center, prospective study

BACKGROUND

Data of tenofovir alafenamide (TAF) in preventing mother-to-child transmission (MTCT) of hepatitis B virus (HBV) are limited. This study aimed to evaluate the effectiveness and safety of TAF for preventing MTCT.

METHODS

Pregnant women with chronic HBV infection, positive for HBeAg and high-level HBV DNA, received oral TAF from gestational weeks 24-28 until postpartum week 4. All infants received HBV immunoprophylaxis. All mothers and infants were followed up until postpartum seven month. The primary outcome was the rate of MTCT at seven month.

RESULTS

Eighty-nine mothers delivered and 91 infants were born. All were followed up to postpartum seven month. TAF was initiated at a mean gestational age of 25.0 (±1.0) weeks with the mean treatment duration of 14.3 (±1.2) weeks before delivery; 92.1% (82/89) mothers discontinued TAF, the median [IQR] time was 5.9 [4.7] weeks postpartum. The HBsAg positive rate was 0% at seven months in 91 infants, no growth retardation and congenital defects. All mothers were tolerated during TAF treatment. At delivery, 82.02% (73/89) mothers achieved HBV DNA < 200,000 IU/ml, 21.35% (19/89) achieved HBV DNA < 500 IU/ml. No significant changes on the mean (±SD) serum phosphate between baseline (1.20 ± 0.10 mmol/L) and at delivery (1.21 ± 0.13 mmol/L, p > .05). Serum creatinine at delivery (52.23 ± 8.50 µmol/L) was higher than baseline (45.97 ± 5.60 µmol/L, p < .05), but within normal range. Nine of 82 mothers stopped TAF treatment after delivery had mild ALT elevation.

CONCLUSION

TAF therapy initiated during the second trimester was effective in preventing MTCT with no safety concerns for mothers and infants (ClinicalTrials.gov number, NCT04065230).

Efficacy of Peginterferon alfa-2b in Nucleoside Analogue Experienced Patients with Negative HBeAg and Low HBsAg: A Non-Randomized Clinical Trial

INTRODUCTION

Hepatitis B surface antigen (HBsAg) clearance is the treatment goal for hepatitis B e antigen (HBeAg)-negative patients with chronic hepatitis B (CHB). However, its rate is extremely low with nucleoside (acid) analogues (NAs) monotherapy. Peginterferon could enhance HBsAg clearance. This study aimed to evaluate the efficacy of peginterferon alfa-2b (PegIFNα-2b) in NAs-experienced patients with CHB with negative HBeAg and low HBsAg level.

METHODS

HBeAg-negative patients with CHB who had received NAs therapy over 24 weeks with HBsAg < 1500 IU/mL and HBV DNA < 100 IU/mL were enrolled. Patients received either PegIFNα-2b add-on therapy (n = 108) or continuous NAs monotherapy (n = 75). The primary endpoint was HBsAg clearance rate at week 48.

RESULTS

At week 48, serum HBV DNA was undetectable among all PegIFNα-2b add-on therapy patients. Almost all patients maintained HBV DNA suppression in the PegIFNα-2b add-on group (100%, 108/108) and NAs monotherapy group (97.33%, 73/75). Only patients with PegIFNα-2b add-on therapy achieved HBsAg clearance (50.93%, 55/108) and HBsAg seroconversion (48.15%, 52/108) at week 48. Patients with baseline HBsAg < 100 IU/mL achieved the highest HBsAg clearance rate and HBsAg seroconversion rate at week 48 (60.87%, 28/46 and 58.70%, 27/46 respectively). HBsAg clearance and HBsAg seroconversion at week 72 had no significant difference with continuing or discontinuing PegIFNα-2b therapy after 48 weeks of treatment. PegIFNα-2b add-on therapy was well tolerated.

CONCLUSIONS

PegIFNα-2b add-on therapy increases HBsAg clearance rate and seroconversion rate for HBeAg-negative patients with CHB, particularly for those with lower HBsAg level. It would be unnecessary to prolong PegIFNα-2b duration after 48 weeks of PegIFNα-2b treatment.

Impact of Introducing Hepatitis B Birth Dose Vaccines into the Infant Immunization Program in Burkina Faso: Study Protocol for a Stepped Wedge Cluster Randomized Trial (NéoVac Study)

To achieve global hepatitis elimination by 2030, it is critical to prevent the mother-to-child transmission (MTCT) of hepatitis B virus (HBV). Since 2009, the WHO has recommended administering hepatitis B vaccine to all neonates within 24 h of birth to prevent MTCT. However, many countries in sub-Saharan Africa only provide hepatitis B immunization at the age of 6, 10, and 14 weeks or 8, 12, and 16 weeks using a combined vaccine. To accelerate the introduction of the hepatitis B birth dose vaccine (HepB-BD) into sub-Saharan Africa, it is critical to establish to what extent the addition of HepB-BD can further reduce HBV transmission in areas where three-dose infant vaccination has been implemented. We therefore designed a study to evaluate the impact, acceptability, and cost-effectiveness of incorporating the HepB-BD into the routine immunization program in a real-life field condition in Burkina Faso, where the hepatitis B vaccination is currently scheduled at 8-12-16 weeks. Through a multidisciplinary approach combining epidemiology, anthropology, and health economics, the Neonatal Vaccination against Hepatitis B in Africa (NéoVac) study conducts a pragmatic stepped wedge cluster randomized controlled trial in rural areas of the Hauts-Bassins Region. The study was registered in ClinicalTrials.gov (identifier: NCT04029454). A health center is designated as a cluster, and the introduction of HepB-BD will be rolled out sequentially in 24 centers. Following an initial period in which no health center administers HepB-BD, one center will be randomly allocated to incorporate HepB-BD. Then, at a regular interval, another center will be randomized to cross from the control to the intervention period, until all 24 centers integrate HepB-BD. Pregnant women attending antenatal care will be systematically invited to participate. Infants born during the control period will follow the conventional immunization schedule (8-12-16 weeks), while those born in the interventional period will receive HepB-BD in addition to the routine vaccines (0-8-12-16 weeks). The primary outcome, the proportion of hepatitis B surface antigen (HBsAg) positivity in infants aged at 9 months, will be compared between children born before and after HepB-BD introduction. The study will generate data that may assist governments and stakeholders in sub-Saharan Africa to make evidence-based decisions about whether to add HepB-BD into the national immunization programs.

Epidemiological projections of viral-induced hepatocellular carcinoma in the perspective of WHO global hepatitis elimination

Hepatitis B is an eminent risk factor for hepatocellular carcinoma (HCC) in Southeast Asia and sub-Saharan Africa, whereas hepatitis C is a key risk factor for HCC in Western Europe and North America. Increased awareness of the global burden of viral hepatitis resulted, in May 2016, in the adoption of the first global health sector strategy on viral hepatitis by the World Health Assembly, which calls for the elimination of viral hepatitis as a public health threat by 2030. Although the incidence of liver cancer resulting from viral infections has increased since the 1990s, the implementation of public health interventions, such as hepatitis B vaccination and antiviral therapies might have reduced the global burdens of HCC. Hepatitis B immunization in infancy has been associated with a reduction in the risk of infant fulminant hepatitis, chronic liver disease, and HCC in Taiwan. Achieving viral hepatitis elimination by 2030 can be accelerated by improving the access to HCC screening programs. HCC surveillance programs in developed countries must be refined to increase an access to personalized surveillance program, whereas the limited access to surveillance and treatment of HCC in developing countries remains a significant public health issue.

Efficacy and safety of antiviral prophylaxis during pregnancy to prevent mother-to-child transmission of hepatitis B virus: a systematic review and meta-analysis

BACKGROUND

To eliminate mother-to-child transmission (MTCT) of hepatitis B virus (HBV), peripartum antiviral prophylaxis might be required for pregnant women infected with HBV who have a high risk of MTCT despite infant immunoprophylaxis. We aimed to determine the efficacy and safety of peripartum antiviral prophylaxis to inform the 2020 WHO guidelines.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Embase, Scopus, CENTRAL, CNKI, and Wanfang for randomised controlled trials and non-randomised studies of peripartum antiviral prophylaxis versus placebo or no prophylaxis, with no language restriction, published from database inception until March 28, 2019. We used search terms covering HBV, antiviral therapy, and pregnancy. We included studies that enrolled pregnant women with chronic infection with HBV who received antiviral prophylaxis anytime during pregnancy; that included any of the following antivirals: adefovir, emtricitabine, entecavir, lamivudine, telbivudine, tenofovir alafenamide fumarate, and tenofovir disoproxil fumarate; and that reported the following outcomes: MTCT, indicated by infant HBsAg positivity or HBV DNA positivity, or both, at age 6-12 months, and any infant or maternal adverse events. Two reviewers independently extracted data. Our primary endpoint was MTCT based on infant HBsAg positivity. We assessed pooled odds ratios (ORs) of the efficacy of peripartum antiviral prophylaxis to reduce the risk of MTCT. We assessed safety of prophylaxis by pooling risk differences. The protocol for the systematic review was pre-registered in PROSPERO, CRD42019134614.

FINDINGS

Of 7463 articles identified, 595 articles were eligible for full-text review and 129 studies (in 157 articles) were included. The following antivirals were assessed in the meta-analysis: tenofovir disoproxil fumarate 300 mg (19 studies, with 1092 mothers and 1072 infants), lamivudine 100-150 mg (40 studies, with 2080 mothers and 2007 infants), and telbivudine 600 mg (83 studies, with 6036 mothers and 5971 infants). The pooled ORs for randomised controlled trials were similar, at 0·10 (95% CI 0·03-0·35) for tenofovir disoproxil fumarate, 0·16 (0·10-0·26) for lamivudine, and 0·14 (0·09-0·21) for telbivudine. The pooled ORs in non-randomised studies were 0·17 (0·10-0·29) for tenofovir disoproxil fumarate, 0·17 (0·12-0·24) for lamivudine, and 0·09 (0·06-0·12) for telbivudine. We found no increased risk of any infant or maternal safety outcomes after peripartum antiviral prophylaxis.

INTERPRETATION

Peripartum antiviral prophylaxis is highly effective at reducing the risk of HBV MTCT. Our findings support the 2020 WHO recommendation of administering antivirals during pregnancy, specifically tenofovir disoproxil fumarate, for the prevention of HBV MTCT.

FUNDING

World Health Organization.

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.

Development of a simple score based on HBeAg and ALT for selecting patients for HBV treatment in Africa

BACKGROUND & AIMS

To eliminate hepatitis B virus (HBV) infection, it is essential to scale up antiviral treatment through decentralized services. However, access to the conventional tools to assess treatment eligibility (liver biopsy/Fibroscan®/HBV DNA) is limited and not affordable in resource-limited countries. We developed and validated a simple score to easily identify patients in need of HBV treatment in Africa.

METHODS

As a reference, we used treatment eligibility determined by the European Association for the Study of the Liver based on alanine aminotransferase (ALT), liver histology and/or Fibroscan and HBV DNA. We derived a score indicating treatment eligibility by a stepwise logistic regression using a cohort of chronic HBV infection in The Gambia (n = 804). We subsequently validated the score in an external cohort of HBV-infected Africans from Senegal, Burkina Faso, and Europe (n = 327).

RESULTS

Out of several parameters, two remained in the final model, namely HBV e antigen (HBeAg) and ALT level, constituting a simple score (treatment eligibility in Africa for the hepatitis B virus: TREAT-B). The score demonstrated a high area under the receiver operating characteristic curve (0.85, 95% CI 0.79-0.91) in the validation set. The score of 2 and above (HBeAg-positive and ALT ≥20 U/L or HBeAg-negative and ALT ≥40 U/L) had a sensitivity and specificity for treatment eligibility of 85% and 77%, respectively. The sensitivity and specificity of the World Health Organization criteria based on the aspartate aminotransferase-to-platelet ratio index (APRI) and ALT were 90% and 40%, respectively.

CONCLUSIONS

A simple score based on HBeAg and ALT had a high diagnostic accuracy for the selection of patients for HBV treatment. This score could be useful in African settings.

LAY SUMMARY

Limited access to the diagnostic tools used to assess treatment eligibility (liver biopsy/Fibroscan/hepatitis B virus DNA) has been an obstacle to the scale up of hepatitis B treatment programs in low- and middle-income countries. Using the data from African patients with chronic HBV infection, we developed and validated a new simple diagnostic score for treatment eligibility, which only consists of hepatitis B virus e antigen and alanine aminotransferase level. The diagnostic accuracy of the score for selecting patients for HBV treatment was high and could be useful in African settings.

Antiviral therapy in hepatitis B virus-infected children with immune-tolerant characteristics: A pilot open-label randomized study

BACKGROUND & AIM

Chronic infection with hepatitis B virus (HBV) in children is a serious health problem worldwide. How to treat children with immune-tolerant chronic hepatitis B infection, commonly characterized by hepatitis B e antigen (HBeAg) positivity, high viral load, normal or mildly elevated alanine aminotransferase and no or minimal inflammation in liver histology, remains unresolved. This trial aims to study the benefits of antiviral therapy in children with these characteristics.

METHODS

This is a pilot open-label randomized controlled study. From May 2014 to April 2015, 69 treatment-naive chronically HBV-infected children, aged 1 to 16 years, who had immune-tolerant characteristics were recruited to this trial and randomly assigned, in a 2:1 ratio, to treatment group and control group. Patients in the treatment group received either interferon-α (IFN) monotherapy or consecutively received IFN monotherapy, combination therapy of IFN and lamivudine (LAM), and LAM therapy alone. All patients were observed until week 96.

RESULTS

At baseline, epidemiological, biochemical, serological, virological and histological indices were consistent across the treatment and control groups. Of the 46 patients in the treatment group, 73.91% had undetectable serum HBV DNA, 32.61% achieved HBeAg seroconversion and 21.74% lost hepatitis B surface antigen (HBsAg) at the endpoint. No LAM resistance emerged at week 96. In the control group, only one (4.35%) patient underwent spontaneous HBeAg seroconversion and had undetectable serum HBV DNA during observation, and moreover, none developed HBsAg clearance. For all patients, no serious adverse events were observed.

CONCLUSION

Antiviral treatment with a sequential combination of IFN and LAM resulted in a significant improvement in the rates of undetectable serum HBV DNA, HBeAg seroconversion and HBsAg loss in children with chronic HBV infection and immune-tolerant characteristics.

LAY SUMMARY

There is a lack of data regarding treatment of immune-tolerant chronic hepatitis B (CHB). It remains unresolved how children with immune-tolerant CHB should be treated. This paper reports the outcomes from a pilot open-label randomized controlled trial on antiviral therapy in children with immune-tolerant characteristics. It shows that a sequential combination of interferon-α and lamivudine was beneficial.

An expert consensus for the management of chronic hepatitis B in Asian Americans

BACKGROUND

Hepatitis B virus (HBV) infection is common with major clinical consequences. In Asian Americans, the HBsAg carrier rate ranges from 2% to 16% which approximates the rates from their countries of origin. Similarly, HBV is the most important cause of cirrhosis, hepatocellular carcinoma (HCC) and liver related deaths in HBsAg positive Asians worldwide.

AIM

To generate recommendations for the management of Asian Americans infected with HBV.

METHODS

These guidelines are based on relevant data derived from medical reports on HBV from Asian countries as well as from studies in the HBsAg positive Asian Americans. The guidelines herein differ from other recommendations in the treatment of both HBeAg positive and negative chronic hepatitis B (CHB), in the approach to HCC surveillance, and in the management of HBV in pregnant women.

RESULTS

Asian American patients, HBeAg positive or negative, with HBV DNA levels >2000 IU/mL (>10⁴ copies/mL) and ALT values above normal are candidates for anti-viral therapy. HBeAg negative patients with HBV DNA >2000 IU/mL and normal ALT levels but who have either serum albumin <3.5 g/dL or platelet count <130 000 mm³ , basal core promoter (BCP) mutations, or who have first-degree relatives with HCC should be offered treatment. Patients with cirrhosis and detectable HBV DNA must receive life-long anti-viral therapy. Indications for treatment include pregnant women with high viraemia, coinfected patients, and those requiring immunosuppressive therapy. In HBsAg positive patients with risk factors, life-long surveillance for HCC with alpha-fetoprotein (AFP) testing and abdominal ultrasound examination at 6-month intervals is required. In CHB patients receiving HCC treatments, repeat imaging with contrast CT scan or MRI at 3-month intervals is strongly recommended. These guidelines have been assigned to a Class (reflecting benefit vs. risk) and a Level (assessing strength or certainty) of evidence.

CONCLUSIONS

Application of the recommendations made based on a review of the relevant literature and the opinion of a panel of Asian American physicians with expertise in HBV treatment will inform physicians and improve patient outcomes.

Telbivudine therapy for gravidas with chronic hepatitis B infection and patients at risk of renal impairment

Hepatitis B virus infection is currently the most important cause of chronic viral hepatitis worldwide and is one of the most frequent causes of end-stage liver disease. With the international implementation of the hepatitis B vaccine and combined prophylaxis for infants born to HBsAg(+) mothers, the prevalence of hepatitis B has decreased remarkably. However, intra-uterine transmission has become a critical bottleneck for eliminating hepatitis B infection. The efficacy of nucleos(t)ide analogs on inhibiting hepatitis B replication has been widely confirmed, and the quality of life and the survival of individuals with chronic hepatitis B (CHB) have improved to a great degree. However, with the availability of long-term antiviral treatment and the ever increasing ageing population, renal disorders should be considered when choosing antiviral medicines. The antiviral efficacy and safety of telbivudine (LdT) have been shown in patients with CHB infection, and LdT is approved as a class B drug for pregnancy. Furthermore, the renal protective function of LdT has been demonstrated recently. In this review, we will focus on the efficacy and safety of LdT in gravidas with CHB infection, as well as the renal protective function of LdT in CHB patients. LdT might provide physicians with a solid option for effectively treating patients with CHB, especially gravidas or those either with or at risk of renal impairment.

Natural history of chronic HBV infection in West Africa: a longitudinal population-based study from The Gambia

BACKGROUND

The natural history of chronic HBV infection in sub-Saharan Africa is unknown. Data are required to inform WHO guidelines that are currently based on studies in Europe and Asia.

METHODS

Between 1974 and 2008, serosurveys were repeated in two Gambian villages, and an open cohort of treatment-naive chronic HBV carriers was recruited. Participants were followed to estimate the rates of hepatitis B e (HBeAg) and surface antigen (HBsAg) clearance and incidence of hepatocellular carcinoma (HCC). In 2012-2013, a comprehensive liver assessment was conducted to estimate the prevalence of severe liver disease.

RESULTS

405 chronic carriers (95% genotype E), recruited at a median age of 10.8 years, were followed for a median length of 28.4 years. Annually, 7.4% (95% CI 6.3% to 8.8%) cleared HBeAg and 1.0% (0.8% to 1.2%) cleared HBsAg. The incidence of HCC was 55.5/100 000 carrier-years (95% CI 24.9 to 123.5). In the 2012-2013 survey (n=301), 5.5% (95% CI 3.4% to 9.0%) had significant liver fibrosis. HBV genotype A (versus E), chronic aflatoxin B1 exposure and an HBsAg-positive mother, a proxy for mother-to-infant transmission, were risk factors for liver fibrosis. A small proportion (16.0%) of chronic carriers were infected via mother-to-infant transmission; however, this population represented a large proportion (63.0%) of the cases requiring antiviral therapy.

CONCLUSIONS

The incidence of HCC among chronic HBV carriers in West Africa was higher than that in Europe but lower than rates in East Asia. High risk of severe liver disease among the few who are infected by their mothers underlines the importance of interrupting perinatal transmission in sub-Saharan Africa.

Systematic review with meta-analysis: the risk of mother-to-child transmission of hepatitis B virus infection in sub-Saharan Africa

BACKGROUND

The risk of mother-to-child transmission of hepatitis B virus (HBV) has been quoted as 70-90% among women positive for hepatitis B surface antigen (HBsAg) and e antigen (HBeAg), and 5-30% among HBsAg-positive HBeAg-negative women. These risks are derived from Asia; little is known about sub-Saharan Africa.

AIM

To determine the risk of mother-to-child transmission in sub-Saharan Africa, according to maternal HBeAg and type of prophylaxis.

METHODS

We searched Medline, Global Health, Embase, African Journals Online and African Index Medicus. We included observational or interventional studies that enrolled infants of HBV-infected women, and that tested for HBsAg or HBV DNA between 3 and 12 months of age.

RESULTS

Fifteen articles from 11 African countries were included. Among HBeAg-positive women, the pooled risk was 38.3% (95% CI: 7.0-74.4%) without prophylaxis, which was significantly lower than the lower bound of 70-90% risk in the literature (P = 0.007). Among HBeAg-negative women, the pooled risk was 4.8% (95% CI: 0.1-13.3%) without prophylaxis, which lays within the lower range of the 5-30% risk in Asia. By extrapolating the pooled transmission risks to the number of births to infectious mothers, an estimated 1% of newborns (n = 367 250) are annually infected with HBV at birth in sub-Saharan Africa.

CONCLUSIONS

Compared to Asia, the risk of mother-to-child transmission is low in sub-Saharan Africa. However, the annual number of infants perinatally infected with HBV is twice the number of incident paediatric HIV infections in sub-Saharan Africa (n = 190 000). This highlights the importance of preventing mother-to-child transmission of HBV in sub-Saharan Africa, which has been long neglected.

Hepatitis B immunity in the pediatric liver transplant population

PURPOSE OF REVIEW

Hepatitis B virus (HBV) infection contributes significantly to vaccine-preventable disease related deaths, and insufficient HBV immunity may have unique implications for the pediatric liver transplant population. This article reviews the significance of HBV infection and the vaccination and screening measures needed to achieve adequate HBV immunity in these children.

RECENT FINDINGS

HBV non-immunity among transplant candidates is higher than expected, even after appropriate completion of the vaccine series. Annual measurement of quantifiable HBV surface antibody in this vulnerable group should guide administration of booster and/or re-vaccination, improving immunoprotection from this potentially deadly hepatotropic virus. The liver plays a vital role in immune regulation; it induces immune tolerance and competence and both clears antigens from the circulation and generates liver-primed memory cells through antigen presentation via hepatic scavenger cells. Lymphocyte populations are depleted in patients with liver disease.

SUMMARY

Immunity provided during early childhood against HBV infection is important to both pediatric liver transplant candidates and aging recipients. Appropriate vaccination and achievement of adequate immunity pre-transplant and post-transplant is critical. The field of pediatric transplantation is ripe for functional cellular and humoral immunity studies that examine factors which predict poor immune response to childhood vaccines, particularly HBV.

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.

Seroprevalence of hepatitis B among pregnant women in Varna Region, Bulgaria

The aim of the present study was to assess the prevalence of hepatitis B surface antigen among pregnant women in Varna Region, Bulgaria. During the period 2009-2013, an average prevalence of 2.26% (95%CI 1.75, 2.91) was measured in a total number of 2,700 samples. Analysis demonstrated that rural residence and minority ethnic origin are important risk factors for hepatitis B infection among pregnant women with hazard ratios of 2.40 (95%CI 1.46, 3.94), and 2.43 (95%CI 1.46, 4.05) when compared with urban residence and ethnic majority origin, respectively. J. Med. Virol. 88:2012-2015, 2016. © 2016 Wiley Periodicals, Inc.

Children with Chronic Hepatitis B in the United States and Canada

OBJECTIVES

To test the hypothesis that children with chronic hepatitis B living in the US and Canada would have international origins and characteristic hepatitis B virus (HBV) genotypes and laboratory profiles.

STUDY DESIGN

Clinical characteristics of children enrolled in the Hepatitis B Research Network were collected from 7 US and Canadian centers.

RESULTS

Children (n = 343) with an age range of 1.0-17.8 years were enrolled; 78% of the children were Asian, 55% were adopted, and 97% had international origins with either the child or a parent born in 1 of 31 countries. The majority had HBV genotype B (43%) or C (32%), and the remainder had genotype A (5%), D (16%), E (4%), or multiple (<1%). Children with genotype B or C were more likely to be Asian (98% and 96%), more consistently hepatitis B envelope antigen positive (95% and 82%), had higher median HBV DNA levels (8.2 and 8.3 log10 IU/mL), and less frequently had elevated alanine aminotransferase values (43% and 57%) compared with children with other genotypes. The percentage of hepatitis B envelope antigen positivity and of those with HBV DNA ≥6 log₁₀ IU/mL declined with age.

CONCLUSIONS

The majority of children in the Hepatitis B Research Network have HBV genotypes that reflect their international origins. Clinical and laboratory data differ substantially by patient age and HBV genotype. Use of these data can help drive the development of optimal strategies to manage and treat children with chronic hepatitis B.

Is liver biopsy still needed in children with chronic viral hepatitis?

Liver biopsy is a standard method used for obtaining liver tissue for histopathological evaluation. Since reliable serological and virological tests are currently available, liver biopsy is no longer needed for the etiological diagnosis of chronic hepatitis B and C. However, liver histology remains the gold standard as a prognostic tool, providing information about the liver disease progression (grading of necroinflammatory activity and staging of fibrosis) and serving clinicians in the management and therapeutic decisions. In general, histopathological evaluation is indicated before starting the antiviral treatment. Main limitations of the liver biopsy include its invasive and painful procedure, sampling errors and the inter- and intra-observer variability. In addition, indications for the liver biopsy in pediatric patients with chronic viral hepatitis were questioned recently, and efforts have been made toward the development of non-invasive methods as an alternative to the liver biopsy. The most commonly used methods are novel imaging studies (elastography) and combinations of biomarkers. However, to date, none of these tests was validated in children with chronic viral hepatitis. In this review, we present the current status of the liver biopsy in the management of chronic viral hepatitis B and C in pediatric population, including specific indications, complications, contraindications, problems, limitations, and alternative non-invasive methods.

Hepatitis B and Delta Virus: Advances on Studies about Interactions between the Two Viruses and the Infected Hepatocyte

The mechanisms determining persistence of hepatitis B virus (HBV) infection and long-term pathogenesis of HBV-associated liver disease appear to be multifactorial. Although viral replication can be efficiently suppressed by the antiviral treatments currently available, viral clearance is generally not achieved since HBV has developed unique replication strategies, enabling persistence of its genome within the infected hepatocytes. Moreover, no direct antiviral therapy exists for the more than 15 million people worldwide that are also coinfected with the hepatitis delta virus (HDV), a defective virus that needs the HBV envelope proteins for propagation. The limited availability of robust HBV and HDV infection systems has hindered the understanding of the complex network of virus-virus and virus-host interactions that are established in the course of infection and slowed down progress in drug development. Since chronic HBV/HDV coinfection leads to the most severe form of chronic viral hepatitis, elucidation of the molecular mechanisms regulating virus-host interplay and pathogenesis are urgently needed. This article summarizes the current knowledge regarding the interactions among HBV, HDV, and the infected target cell and discusses the dependence of HDV on HBV activity and possible future therapeutic approaches.

Effects of tenofovir disoproxil fumarate in hepatitis B e antigen-positive patients with normal levels of alanine aminotransferase and high levels of hepatitis B virus DNA

BACKGROUND & AIMS

Little is known about the benefit of antiviral therapy for hepatitis B e antigen (HBeAg)-positive patients with high viral load and normal levels of alanine aminotransferase. We evaluated the effects of single and combination therapies in immune-tolerant patients with chronic hepatitis B.

METHODS

In a double-blind study, nucleos(t)ide-naïve patients with high levels of hepatitis B virus (HBV) DNA who were positive for HBeAg and had normal levels of alanine aminotransferase were randomly assigned to groups given either oral tenofovir disoproxil fumarate (TDF, 300 mg) and placebo (n = 64) or a combination of TDF (300 mg) and emtricitabine (200 mg, n = 62) for 192 weeks. The primary end point was proportion of patients with serum levels of HBV DNA <69 IU/mL at week 192.

RESULTS

The study population (mean age was 33 years; 89% were Asian) was predominantly infected with HBV genotypes B and C (93%), 99% were HBeAg positive with a mean baseline level of HBV DNA of 8.41 log10 IU/mL. At week 192, 55% of patients (35 of 64) in the TDF+placebo group and 76% of patients (47 of 62) in the TDF+emtricitabine group had levels of HBV DNA <69 IU/mL (P = .016). No patients were found to have viral resistance to therapy. HBeAg seroconversion occurred in 3 patients (5%), all in the TDF+placebo group; no patient had loss of hepatitis B surface antigen. In multivariate analysis, female sex (odds ratio = 7.05; P = .002) and TDF+emtricitabine treatment (odds ratio = 3.9; P = .01) were associated with a favorable response. Both regimens were well tolerated.

CONCLUSIONS

In HBeAg-positive patients with chronic HBV infection, high viral loads, normal levels of alanine aminotransferase, and therapy with the combination of TDF and emtricitabine provided better viral suppression than TDF alone, although rates of HBeAg seroconversion and hepatitis B surface antigen loss were low.

Management of chronic hepatitis B in children: an unresolved issue

Although a rather benign course of chronic hepatitis B virus (HBV) infection during childhood has been described, 3-5% and 0.01-0.03% of chronic carriers develop cirrhosis or hepatocellular carcinoma before adulthood. Considering the whole lifetime, the risk of hepatocellular carcinoma rises to 9-24% and the incidence of cirrhosis to 2-3% per year. The aim of this article is to review the current knowledge regarding the natural history and treatment of chronic hepatitis B in children and to focus on critical aspects and unresolved questions in the management of childhood HBV infection. A literature search was carried out on MEDLINE, EMBASE, and Web of Science for articles published in English in peer-reviewed journals from January 1980 to February 2013. The search terms used included "Hepatitis B virus infection," "children," "HBV," "interferon," "lamivudine," "adefovir," "entecavir," and "tenofovir." Articles resulting from these searches and relevant references cited in the articles retrieved were reviewed. The current goals of therapy are to suppress viral replication, reduce liver inflammation, and reverse liver fibrosis. Therapeutic options for children are currently limited, and the risk for viral resistance to current and future therapies is a particular concern. Based on the data available at this time, it is the consensus of the panel that it is not appropriate to treat children in the immune-tolerant phase or in the inactive carrier state. For children in the immune-active or reactivation phases, liver histology can help guide treatment decisions. Outside of clinical trials, interferon is the agent of choice in most cases; currently, available nucleoside analogs are secondary therapies.

Unrecognized hepatitis B in pre-screened children with hematologic and oncologic conditions

BACKGROUND

This study evaluates the effectiveness and interpretation of hepatitis B (HBV) screening in an at-risk cohort of children with cancer or blood disorders.

PROCEDURE

We conducted a retrospective epidemiologic analysis of children who screened positive for HBV (HBsAg, HbcAb) from 1999 to 2009 at a quaternary children's hospital, focusing on patients with hematologic and oncologic conditions. Descriptive statistics were generated for demographics and serologies. Follow-up of positive serologies and clinical outcomes were analyzed.

RESULTS

A total of 12,754 children were screened for HBV. Of 391 that screened positive, 118 had a hematologic or oncologic diagnosis. Leukemia, anemia, and thrombocytopenia comprised 84% of diagnoses. The majority (98%) tested HBcAb positive but only 20% received confirmatory HBV DNA testing. Three patients (13% of those HBV DNA tested) were identified to have chronic disease. HBV was not a known pre-existing condition, and chemotherapy preceded HBV diagnosis in all cases.

CONCLUSIONS

The majority of children with cancer or blood disorders who screened HBV positive did not receive follow-up DNA testing, exposing them to reactivation risk and delaying definitive therapy. HBcAb may be the only indicator of chronic HBV infection and DNA confirmation should be routine. Our findings suggest a significant number of additional patients eligible for HBV treatment may have been identified with reflexive DNA testing.

What physicians should know about the management of chronic hepatitis B in children: East side story

Understanding the natural course of chronic hepatitis B virus (HBV) infection is very important for the management and treatment of chronic hepatitis B in children. Based on treatment guidelines, the management of HBV carriers and treatment of active hepatitis have been advancing and resulted in increased survival, as well as decreased risks of complications such as liver cirrhosis and hepatocellular carcinoma. Development of a continuing medical education (CME) program for primary physicians becomes an important responsibility of pediatric hepatologists. CME could prevent misdiagnosis and unnecessary treatment that could lead to liver complications or antiviral resistance. In addition, education of patients and their parents is necessary to achieve better therapeutic outcomes.

HIV/HBV coinfection in children and antiviral therapy

Small cohort studies from countries where both HIV and HBV are endemic demonstrate prevalence rates of chronic hepatitis B in HIV-infected children of between 1 and 49%. While data on coinfected children are limited, results from studies in adults with HIV/HBV coinfection raise the concern that coinfected children may be at a higher risk of liver disease, hepatic fibrosis and cirrhosis. With the scale-up of combination antiretroviral therapy worldwide, of which lamivudine is included in most first-line regimens, coinfected children treated with lamivudine risk development of HBV resistance mutations. This article summarizes the current literature relevant to HIV/HBV coinfection in children, the options for treatment and highlights priorities for future research.

Chronic hepatitis B in children and adolescents: epidemiology and management

Hepatitis B virus (HBV) infection is a worldwide health problem, which can cause acute liver failure, acute hepatitis, chronic hepatitis, liver cirrhosis, and liver cancer. It is most prevalent in Asia, Africa, Southern Europe, and Latin America. Approximately 2 billion people in the world have been infected by HBV, with more than 350 million as chronic carriers. Implementation of the HBV vaccine led to a significant reduction in viral transmission in many areas of the world; however, it remains highly endemic in many developing countries. The main source of infection in childhood is via perinatal transmission or horizontal transmission during preschool years. The majority of children with chronic hepatitis B (CHB) infection are asymptomatic; however, they may develop progressive disease and are at increased risk of advanced liver disease or liver cancer before their third decade. All children with chronic HBV infection should be regularly monitored for disease progression. The goal of therapy for children with CHB is to arrest disease progression and reduce the risk of developing cirrhosis and cancer. The available medications have a low success rate because of immunotolerance in the child and the development of viral resistance to standard therapy. Therefore, case selection and determination of the best time to commence treatment are essential to increase treatment efficacy and reduce the risk of viral resistance.

Role of peripheral blood mononuclear cell transportation from mother to baby in HBV intrauterine infection

PURPOSE

We aimed to investigate the role of peripheral blood mononuclear cell transportation from mother to baby in hepatitis B virus (HBV) intrauterine infection.

METHODS

Thirty HBsAg-positive pregnant women in the second trimester and their aborted fetuses were included in this study. Enzyme-linked-immunosorbent-assay was utilized to detect HBsAg in the peripheral blood of pregnant women and the femoral vein blood of their aborted fetuses. HBV-DNA in serum and peripheral blood mononuclear cells (PBMC) and GSTM1 alleles of pregnant women and their aborted fetuses were detected by nested polymerase chain reaction (PCR) and seminested PCR, respectively. We also examined the location of placenta HBsAg and HBcAb using immunohistochemical staining. The expression of placenta HBV-DNA was detected by in situ hybridization.

RESULTS

For the 30 aborted fetuses, the HBV intrauterine infection rate was 43.33%. The HBV-positive rates of HBsAg in peripheral blood, serum, and PBMC were 10% (3/30), 23.33% (7/30), and 33.33% (10/30), respectively. Maternal-fetal PBMC transport was significantly positively correlated with fetal PBMC HBV-DNA (P = 0.004). Meanwhile, the rates of HBV infection gradually decreased from the maternal side to the fetus side of placenta (decidual cells > trophoblastic cells > villous mesenchymal cells > villous capillary endothelial cells). However, no significant correlation between placenta HBV infection and HBV intrauterine infection was observed (P = 0.410).

CONCLUSIONS

HBV intrauterine infection was primarily due to peripheral blood mononuclear cell maternal-fetal transportation in the second trimester in pregnant women.

IL17A gene polymorphisms, serum IL-17A and IgE levels, and hepatocellular carcinoma risk in patients with chronic hepatitis B virus infection

Interleukin (IL)-17A plays important roles in hepatitis B virus (HBV)-induced liver diseases. This study aims to investigate IL17A single nucleotide polymorphisms (SNPs) and the predispositions to chronic HBV infection and hepatocellular carcinoma (HCC) risk and the correlations to IL-17A and IgE levels. Three hundred ninety-five chronic HBV patients, 75 HBV infection resolvers, and 174 healthy controls were included. IL17A SNPs rs8193036 (C/T) and rs2275913 (A/G) and serum IL-17A and IgE levels were determined. HBV infection resolvers had higher rs8193036 allele T and allele T-containing genotypes than HBV patients or controls. Compared with chronic hepatitis, HCC patients had more frequent rs2275913 genotype GG (odds ratios [OR] 3.317, 95% confidence interval [CI] 1.663-6.617, P = 0.001) and allele G (OR 1.844, 95% CI 1.311-2.595, P < 0.001), and more frequent haplotypes CG (OR 1.868, 95% CI 1.256-2.778, P = 0.002) and TG (OR 1.788, 95% CI 1.031-3.101, P = 0.037) of rs8193036 and rs2275913. Comparison of HCC patients with cirrhosis yielded similar findings. Apart from male gender and older ages, IL-17A level (OR 1.020, 95% CI 1.003-1.036, P = 0.019) and rs2275913 genotypes AG and GG (OR 1.704, 95% CI 1.214-2.390, P = 0.006) were factors significantly associated with HCC risk in multivariate analysis in comparison with HBV patients without HCC. These factors remained significant in multivariate analysis in relation to cirrhosis. IL17A rs2275913 genotype GG was associated with significantly increased IL-17A and IgE levels. IL17A polymorphisms may influence HCC risk in chronic HBV infection via regulating IL-17A production.

Predictive factors of lamivudine treatment success in an hepatitis B virus-infected pediatric cohort: a 10-year study

BACKGROUND

Hepatitis B virus (HBV) infections are responsible for the development of chronic hepatitis in 400 million people worldwide. Currently, no consensus exists as to when treatment should be initiated for pediatric patients.

OBJECTIVES

To evaluate the risks and predictive factors of success of lamivudine treatment in children with chronic, active HBV infection.

METHODS

Forty-three children (22 male, median age 9.6 years) chronically infected with HBV and treated between 1998 and 2008 at CHU Ste-Justine (Montreal, Quebec) were included in the present chart review study. Inclusion criteria were detectable hepatitis B surface antigen and hepatitis B e antigen (HBeAg), minimum serum alanine aminotransferase (ALT) level of two times the upper limit of normal and detectable serum HBV DNA for at least three months. Patients received lamivudine for a minimum of six months (median 14 months). Genotyping was performed.

RESULTS

Lamivudine treatment was effective in 35% of cases (15 of 43) and overall virological response (during or after treatment) was achieved in 51% of patients. Three patients harboured suspected lamivudine-resistant mutations and five progressed to HBeAg-chronic HBV. Predictive factors for success of treatment were: younger age at beginning of treatment (P=0.05), elevated ALT levels throughout treatment duration (P=0.003) and loss of HBeAg during treatment (P=0.016). Asian origin did not affect treatment success or spontaneous viral control during follow-up. HBV genotype did not influence treatment success.

CONCLUSIONS

Lamivudine treatment in a carefully selected cohort of HBV patients demonstrated a good rate of success and low incidence of mutation. Younger age at the beginning of treatment and high ALT levels during treatment predicted a positive outcome.

Medical management of chronic liver diseases in children (part I): focus on curable or potentially curable diseases

The management of children with chronic liver disease (CLD) mandates a multidisciplinary approach. CLDs can be classified into 'potentially' curable, treatable non-curable, and end-stage diseases. Goals pertaining to the management of CLDs can be divided into prevention or minimization of progressive liver damage in curable CLD by treating the primary cause; prevention or control of complications in treatable CLD; and prediction of the outcome in end-stage CLD in order to deliver definitive therapy by surgical procedures, including liver transplantation. Curative, specific therapies aimed at the primary causes of CLDs are, if possible, best considered by a pediatric hepatologist. Medical management of CLDs in children will be reviewed in two parts, with part I (this article) specifically focusing on 'potentially' curable CLDs. Dietary modification is the cornerstone of management for galactosemia, hereditary fructose intolerance, and certain glycogen storage diseases, as well as non-alcoholic steatohepatitis. It is also essential in tyrosinemia, in addition to nitisinone [2-(nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione] therapy, as well as in Wilson disease along with copper-chelating agents such as D-penicillamine, triethylenetetramine dihydrochloride, and ammonium tetrathiomolybdate. Zinc and antioxidants are adjuvant drugs in Wilson disease. New advances in chronic viral hepatitis have been made with the advent of oral antivirals. In children, currently available drugs for the treatment of chronic hepatitis B virus infection are standard interferon (IFN)-α-2, pegylated IFN-α-2 (PG-IFN), and lamivudine. In adults, adefovir and entecavir have also been licensed, whereas telbivudine, emtricitabine, tenofovir disoproxil fumarate, clevudine, and thymosin α-1 are currently undergoing clinical testing. For chronic hepatitis C virus infection, the most accepted treatment is PG-IFN plus ribavirin. Corticosteroids, with or without azathioprine, remain the basic strategy for inducing remission in autoimmune hepatitis. Ciclosporin (cyclosporine) and other immune suppressants may be used for patients who do not achieve remission, or who have significant side effects, with corticosteroid/azathioprine therapy. The above therapies can prevent, or at least minimize, progression of liver damage, particularly if started early, leading to an almost normal quality of life in affected children.

Viral hepatitis B in children: clinical characteristics and antiviral treatment

Chronic hepatitis B is a common and frequent disease occurring in children in China. Chronic hepatitis B virus infection during childhood may cause serious clinical consequences. Reasonable treatment is extremely important for children with therapeutic indications. However, there are many challenges in the treatment of chronic hepatitis B in children, such as treatment indications and the choice of antiviral therapy. This paper describes the natural history of HBV infection in children, indications for antiviral therapy, goals of antiviral treatment, and choice of antiviral drugs.