The Rate of Conversion from Immune-tolerant Phase to Early Immune-clearance Phase in Children with Chronic Hepatitis B Virus Infection

Translational Strategies to Eliminate Chronic Hepatitis B in Children: Prophylaxis and Management in East Asian Countries

Translational medical research on hepatitis B virus (HBV) infection and chronic hepatitis B (CHB) pathogenesis provides guidance on strengthening the treatment and prevention strategies of CHB. Preventing vertical transmission is the key to eliminating HBV infection in children. The understanding of HBV replication, hepatocyte turnover, and the fate of covalently closed circular DNA (cccDNA) would help establish a personalized application of the guidelines, especially concerning the discontinuation of nucleos(t)ide analog (NA) treatment in children. Transplacental leakage of HBV-infected maternal blood is suggested as the leading cause of vertical transmission. Prenatal maternal prophylaxis could diminish maternal HBV viremia at delivery, to reduce the risk of neonatal HBV infection. The meaning of the expression "no additional risk of breast milk feeding" is thereby explained. Understanding the untreated natural course of CHB in children and the course changeable by treatment is important to apply individualistic strategies and avoid the immoral selection of treatment indications. NAs with potent efficacy and a high barrier to drug resistance should be used as first-line treatment to reduce the likelihood of NA-resistant HBV development because the rate of mutant HBV emergence might count on the infected hepatocyte turnover rate in chronic HBV infection. Although elimination of intranuclear cccDNA is difficult by NAs alone, a cure is possible by human immunity and hepatocyte turnover. The reduction of intranuclear cccDNA occurs after the destruction of HBV-infected hepatocytes, non-cytolytic immune response, apoptosis of hepatocytes, and compensatory cell proliferation. Therefore, consolidation therapy after NA-induced hepatitis B e-antigen seroconversion must be necessary for a sufficient period. This review also summarizes the treatment strategies of CHB in children based on the practical application of translational research.

Hepatitis B: Who should be treated?-managing patients with chronic hepatitis B during the immune-tolerant and immunoactive phases

New hepatitis B virus (HBV) infections are decreasing owing to improved antiviral therapy and increased HBV vaccination worldwide; however, the number of HBV infections remains a major cause of liver carcinogenesis. HBV triggers cytotoxic immunity to eliminate HBV-infected cells. Therefore, the HBV pathophysiology changes in persistently infected individuals depending on host immune responses and HBV DNA proliferation state. To prevent liver cirrhosis and carcinogenesis caused by HBV, it is important to treat HBV infection at an early stage. Active treatment is recommended for the immunoactive hepatitis B surface-antigen-positive and -negative phase, but not during the immune-inactive phase or immune-tolerant phase; instead, follow-up is recommended. However, these patients should be monitored through regular blood tests to accurately diagnose the immune-inactive or -tolerant phases. The treatment regimen should be determined based on the age, sex, family history of liver cancer, and liver fibrosis status of patients. Early treatment is often recommended due to various problems during the immune-tolerant phase. This review compares the four major international practice guidelines, including those from the Japanese Society of Hepatology, and discusses strategies for chronic hepatitis B treatment during the immune-tolerant, immune-inactive, and resolved phases. Finally, recommended hepatitis B antiviral therapy and follow-up protocols are discussed.

Chronic Hepatitis Is Common and Often Untreated Among Children with Hepatitis B Infection in the United States and Canada

OBJECTIVE

To determine the outcomes of chronic hepatitis B virus (HBV) infection in a large, prospectively studied cohort of children in the US and Canada.

STUDY DESIGN

This was a prospective, observational study of children with chronic HBV enrolled in 7 clinical centers and evaluated at baseline, weeks 24 and 48, and annually thereafter, with analysis of demographic, clinical, physical examination, and blood test data.

RESULTS

Among 362 children followed for a median of 4.2 years, elevated alanine aminotransferase (ALT) levels (>1 upper limit of normal) were present in 72% at last evaluation, including in 60% of children with loss of hepatitis B e antigen during follow-up and 70% of those who were hepatitis B e antigen negative at baseline. Significant ALT flares (male patients ≥400 U/L, female patients ≥350 U/L) occurred in 13 children. Of 129 children who fulfilled the American Association for the Study of Liver Diseases treatment criteria during follow-up, anti-HBV treatment was initiated in only 25. One child died (unrelated to liver disease), 1 developed cirrhosis, but no episodes of cirrhotic decompensation or hepatocellular carcinoma were observed. Decline in platelet count was inversely associated with ALT elevations.

CONCLUSIONS

In a cohort of children with chronic HBV infection in the US and Canada, many children remained at risk of progressive liver disease due to active hepatitis, but major clinical outcomes such as cirrhosis, cancer, and death were rare. Many children who met criteria for treatment remained untreated.

Longitudinal Immune Phenotype Assessment and Serological Outcome in Foreign-born Children With Chronic Hepatitis B

OBJECTIVES

The aim of the study was to assess changes in clinical phenotype, and identify determinants of outcome in children with chronic hepatitis B virus (HBV) infection born in HBV-endemic countries followed in 2 Italian tertiary care centers after immigration or adoption.

METHODS

A prospective observational study on hepatitis B e-antibodies-negative chronic hepatitis B children started on 2002. Patients with liver fibrosis, or those needing antiviral treatment were excluded. Immune active patients were defined those with raised transaminases (alanine aminotransferase > 40 IU/L), immune tolerants those having normal alanine aminotransferase, both exhibiting substantial viral replication (HBV DNA >2000 IU/mL).

RESULTS

Sixty-nine patients (44 boys, median age 4.7 years) had a median follow-up of 53 months. At entry, 18 (26%) children were immune tolerant, 47 (68%) immune active, and 4 had indeterminant immune status. At last follow-up, 14 (78%) of the immune-tolerant patients remained so, whereas only 23 (49%) of the immune active children maintained their initial immune phenotype. Seroconversion to hepatitis B e antibodies (SCHBe) occurred in only 2 (11%) immune tolerants, whereas 13 (28%) immune active patients achieved SCHBe.Ethnicity was the only feature independently correlated to SCHBe: Asian origin reduced by 4.1 times the probability of SCHBe (Asian vs other; odds ratio = 0.24 [95% confidence interval = 0.07-0.76]; P = 0.016) compared to other ethnicities, whereas viral genotype did not influence the outcome.

CONCLUSIONS

Ethnicity and immune status phenotype against HBV, rather than HBV genotype, are the main determinants of SCHBe in foreign-born children with chronic HBV infection.

Cost-effectiveness of couple-based immunization strategy to prevent mother-to-child transmission of hepatitis B virus in China: A decision-analytic Markov model

BACKGROUND

Mother-to-child transmission (MTCT) is the major route of HBV transmission in many parts of the world. We designed couple-based immunization strategy and aimed to assess the cost-effectiveness of this strategy in China.

METHODS

We constructed a decision-analytic Markov model to compared current immunization strategy consisting of hepatitis B vaccination (HepB) for all infants and extra hepatitis B immunoglobulin for infants with HBsAg-positive mothers versus couple-based immunization strategy including additional HBV screening for pre-pregnant couples and HepB for high-risk wives. Costs were assessed from a healthcare system perspective. Number of infants with perinatal HBV infection, life-years (LYs), quality-adjusted life-years (QALYs), and disability-adjusted life-years (DALYs) were used to access effects. We calculated incremental cost-effectiveness ratios (ICERs) and performed sensitivity analysis.

FINDINGS

Based on the birth cohort of 17,578,815 livebirths in China in 2017, couple-based immunization strategy reduced perinatal HBV infection by 18% (9194/51,365) with cost increase of ¥ 41 million, saved 49,986 LYs (ICER: ¥819 per LY saved), gained 48,879 QALYs (ICER: ¥837 per QALY gained) and averted 63,362 DALYs (¥646 per DALY averted) compared with current immunization strategy. These ICERs were below willingness-to-pay levels of China's once GDP per capita (¥59,660), remaining robust in sensitivity analysis.

INTERPRETATION

Under the intermediate endemic of HBV infection in China, implementation of couple-based immunization strategy can improve the efficiency of preventing MTCT of HBV, and is highly cost-effective. This strategy can be a new immunization strategy choice to achieve the target of eliminating hepatitis B by 2030.

FUNDING

National Natural Science Foundation of China.

Cost-effectiveness of augmenting universal hepatitis B vaccination with immunoglobulin treatment: a case study in Zhejiang Province, East China

Objective: To evaluate the cost-effectiveness of the current strategy combining universal vaccination with hepatitis B immunoglobulin (HBIG) treatment for infants of hepatitis B surface antigen (HBsAg) positive mothers compared with universal vaccination with hepatitis B vaccine only.Methods: A decision tree model with a Markov process was constructed and used to simulate the lifetime of the birth cohort in Zhejiang Province during 2016. The current strategy was compared against universal vaccination with respect to costs and health effects. Costs were assessed from the health care system perspective. Health effects were measured by the number of hepatitis B virus (HBV) related diseases and deaths avoided and quality-adjusted life-years (QALYs) gained. The incremental cost‑effectiveness ratio (ICER) is calculated and compared to standard willingness-to-pay thresholds. A one-way sensitivity analysis and a probabilistic sensitivity analysis (PSA) were performed to assess parameter uncertainties.Results: Over the cohort's lifetime, 182 acute symptomatic infections, 2215 chronic infections, 872 cases of cirrhosis, 595 cases of hepatocellular carcinoma (HCC) and 1,350 HBV-related deaths among the cohort of 624,000 infants would be further avoided by the current strategy compared to universal vaccination. Universal vaccination was dominated by the current strategy that produced not only higher total QALYs, but also had lower costs. The results remained robust over a wide range of assumptions.Conclusions: The current strategy was cost saving compared to universal vaccination, and continuing the current strategy is recommended to further decrease the burden of hepatitis B.

Updates in the management of hepatitis B in children

Introduction: Universal infant hepatitis B virus (HBV) vaccination program has reduced HBV infection dramatically in vaccinated young generations. Management of chronically infected children is still challenging concerning high viral load with mostly mild diseases, yet with a nonnegligible proportion of advanced diseases, and long-term effect of antivirals. However, with more potent antivirals approved for pediatric patients, to start antivirals earlier in eligible patients may benefit their outcomes. This review aimed to update the current management of chronic hepatitis B in children.Areas covered: This review covered the natural history of chronic HBV infection, management of chronic hepatitis B in children from the past to the present, current consensus on the treatment of chronic hepatitis B in children, controversies in cessation of oral antivirals, and management of special populations such as pregnancy and co-infections.Expert opinions: Without contraindication, peginterferon is recommended for immune-active children ≥ 3 years old. For those intolerant, decompensating or preferring oral therapy, first-line Nucleos(t)ide analogs (NUC), Entecavir or Tenofovir, may be applied. For immune-tolerant or inactive carriers, close monitoring is crucial. When to stop NUCs and novel therapies for HBV cure await further research.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The management of hepatitis B and hepatitis C in children

In the present paper, we review the increased disease burden of hepatitis B (HBV) and hepatitis C (HCV) infection that is recognized worldwide; especially in children when the most common mode of transmission is vertically from infected mothers. In children with HBV and HCV infection, spontaneous clearance of the virus in the first years of life is not common, in contrast with adults, but these patients often stay asymptomatic until early adulthood, when disease has progressed to chronic hepatitis with increased risk of cirrhosis and its complication, and hepatocellular carcinoma. Due to limited treatment options of HBV infection in the pediatric population, clinicians focus on primary prevention, by vaccinating all infants during their first days of life. Infants born to infected mothers, receive intravenous immunoglobulin on top of the vaccine, and thus preventing transmission in 95% of the infants. While for HCV infection, since there is no vaccine to prevent HCV disease, providers focus primarily on treatment. The treatment landscape of HCV infection in children rapidly evolves, away from interferon regimens, and towards direct-acting antiviral agents that have a safer and more efficacious drug profile. Currently, there are ongoing clinical trials investigating the efficacy and tolerance of direct-acting agents in children below 12 years of age.

Management of chronic hepatitis B patients in immunetolerant phase: what latest guidelines recommend

The natural history of chronic hepatitis B (CHB) is complex and may run through different immune phases that may overlap. In particulars, the immune-tolerant phase is the most interesting and not as well understood as we thought. The concept of true immune tolerance have been under challenged from immunology points of view. The major international guidelines have not yet reached a consensus on the definition of the immune-tolerant phase. While positive hepatitis B e antigen (HBeAg), high serum hepatitis B virus (HBV) DNA and normal serum alanine aminotransferase (ALT) levels are the three key features of this phase, some guidelines also put age into consideration. A new nomenclature, Phase 1 or HBeAg-positive chronic HBV infection, is given by the latest European Association for the Study of the Liver (EASL) published in April 2017. While current guidelines advise against starting antiviral treatment for immune-tolerant CHB patients, some new data suggest treating such patients may reduce the risk of liver fibrosis progression and hepatocellular carcinoma.

A Multicenter Study of the Antiviral Efficacy of Entecavir Monotherapy Compared to Lamivudine Monotherapy in Children with Nucleos(t)ide-naïve Chronic Hepatitis B

BACKGROUND

The aim of this study was to compare the long-term efficacy of entecavir (ETV) and lamivudine (LAM) therapy in children with chronic hepatitis B (CHB) who had not received nucleoside analogue treatment.

METHODS

In this multicenter, retrospective study, we included pediatric CHB patients younger than 20 years who received ETV or LAM treatment for at least 12 months and had no concomitant diseases. All of the patients were followed up every 1 to 3 months. At each visit, the patients underwent clinical evaluation and biochemical testing.

RESULTS

Eight (53.3%), 14 (93.3%), and 2 (15.4%) of the ETV-treated patients achieved virologic suppression, alanine aminotransferase (ALT) normalization and hepatitis B e antigen (HBeAg) seroconversion, respectively, at 1 year. In the ETV group, the cumulative rate of virologic suppression at 3 years was 91.7%, which was significantly higher than that in the LAM group (P < 0.001). The mean duration of treatment before virologic suppression was shorter in the ETV group than in the LAM group (P = 0.040). The cumulative rate of seroconversion in the ETV group at 3 years was 39.4%, which was not significantly different from that in the LAM group (P = 0.439). The ETV group showed lower cumulate rates of virologic breakthrough (33.3% at 6 years) and genotypic mutation than the LAM group (P = 0.033 and P = 0.011, respectively).

CONCLUSION

ETV is superior to LAM in pediatric CHB treatment because of its higher virologic suppression rate and lower cumulative rates of virologic breakthrough and genotypic mutation.

Antiviral Efficacy of Tenofovir Monotherapy in Children with Nucleos(t)ide-naive Chronic Hepatitis B

BACKGROUND

The purpose was to compare the efficacy between tenofovir disoproxil fumarate (TDF) and lamivudine (LMV) in children with nucleos(t)ide-naive chronic hepatitis B (CHB) infection. Patients with CHB were treated with TDF in the immune-reactive phase and compared with a historical control group of patients treated with LMV before the TDF era.

METHODS

Hepatitis B virus (HBV) DNA titer decrements (> 3 log₁₀ IU/mL) were monitored after treatment initiation. The treatment duration for HBV DNA clearance (< 357 IU/mL) and complete response (HBeAg loss and HBV DNA clearance) were analyzed. The follow-up period was 96 weeks.

RESULTS

Sixteen patients were treated with TDF and compared with a historical control group of 24 patients treated with LMV. HBV DNA decrement (> 3 log₁₀ IU/mL) was achieved in 100% (16/16) of the TDF group but in only 62.5% (15/24) of the LMV group (P = 0.005) at 48 weeks. The HBV DNA clearance (< 357 IU/mL) in the TDF and LMV groups was, respectively, as follows: 62.5% (10/16) and 25.0% (6/24) at 12 weeks (P = 0.018), 81.3% (13/16) and 37.5% (9/24) at 24 weeks (P = 0.006), 93.8% (15/16) and 50.0% (12/24) at 48 weeks (P = 0.004), and 100% (16/16) and 54.2% (13/24) at 96 weeks (P = 0.001). Complete response occurred in 41.7% (5/12) of HBeAg-positive patients in the TDF group and 28.6% (6/21) of the LMV group at 96 weeks (P = 0.443).

CONCLUSION

TDF monotherapy for 96 weeks produced a significantly more effective virologic response than LMV monotherapy in children with nucleos(t)ide-naive CHB.

Treatment strategies according to genotype for chronic hepatitis B in children

This review article was requested by editor-in-chief of this journal as 'pediatric CHB treatment' for the upcoming special issue. The main objective of chronic hepatitis B (CHB) treatment is diminishing the risk of complications related to chronic liver disease. In Asia, there are already some reports about hepatocellular carcinoma (HCC) in hepatitis B virus (HBV) infected children. The key points of treatment in children with CHB infections are selection of which patients to treat and conformation of the optimal therapy time that would reduce viral resistance. The choice of therapy is determined by the district (Western/Eastern), HBV genotype, medical accessibility, and economic state of the country. Newly developed nucleos(t)ide analogues (NAs) are potent in children with CHB. However, to improve therapeutic efficacy, physicians are recommended to follow treatment guidelines and determine the specific genotype in the CHB patient. In this article, the treatment of pediatric CHB is reviewed according to differences in genotype.

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.