Chronic hepatitis B in children and adolescents

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.

Infections of the Liver

The portal vein carries blood from the gastrointestinal tract to the liver and in so doing carries microbes as well. The liver may therefore be involved in infections with a myriad number of microbial organisms. While some of these infections most commonly occur in the immunocompromised host, others affect the immune competence. Hepatic infections may be primary in nature or secondary, as part of systemic or contagious disease. The purpose of this chapter is to provide a brief overview of the various infections of the liver in the pediatric patient.

Hepatitis B surface antigen quantity positively correlates with plasma levels of microRNAs differentially expressed in immunological phases of chronic hepatitis B in children

Background and Aim

Children with chronic hepatitis B (CHB) are at high risk of progressive liver disease. It is suggested that a newly-identified panel of 16 microRNAs is important in the pathogenesis of CHB in children. Subviral hepatitis B surface antigen (HBsAg) particles are produced in large excess over infectious virions. Interestingly, circulating HBsAg particles have been shown to carry microRNAs. A thorough characterisation of the identified microRNAs and HBsAg over time in plasma from children with CHB may provide useful information about the natural course of childhood CHB.

Patients and Methods

A cohort of 42 children with CHB was followed over time. Three to five blood samples were obtained from each child at minimum intervals of half a year; in total 180 blood samples. Plasma levels of the 16 microRNAs previously identified were analysed by quantitative real-time polymerase-chain-reaction. Plasma HBsAg was quantified using ARCHITECT® HBsAg assay.

Results

The presence of 14/16 plasma microRNAs in children with CHB was confirmed. All 14 microRNAs were significantly differentially expressed in different immunological phases of the disease. MicroRNA plasma levels were highest in immune-tolerant children, lower in immune-active children, and reached the lowest values in immune-inactive children, p<0.001. Plasma levels of four microRNAs decreased significantly over time in immune-tolerant and immune-active children whereas the microRNA plasma levels were stable in immune-inactive children, p<0.004. HBsAg quantity was positively correlated with plasma levels of 11/14 microRNAs, p<0.004.

Conclusion

This is the first study to characterise plasma microRNAs and HBsAg over time in children with CHB. Our data suggest that plasma levels of selected microRNAs and HBsAg are inversely correlated with immunological control of CHB in children. Further studies are, however, needed to advance the understanding of microRNAs and HBsAg in the pathogenesis of CHB in children.

What evidence exists to support antiviral treatment in children with chronic hepatitis B?

Many questions are unanswered on the optimal management of chronically HBV-infected children. Chronic hepatitis B is generally a mild disease in children; however, response to therapy is partial and limited to specific subgroups, and available drugs have no proven advantage on long-term course of disease versus no treatment, and are hampered by numerous limitations. Studies on the natural history of chronic hepatitis B and the long-term results of the therapeutic schedules adopted so far should be critically appraised. A balance between the potential benefits of the treatment and its side effects, and the spontaneous course of the disease left untreated should be made.

Occult hepatitis B virus infection in anti-HBs-positive infants born to HBsAg-positive mothers in China

Objective

To investigate the prevalence of occult HBV infection (OBI) among children and to characterize virology of occult HBV, we conducted an epidemiological survey.

Methods

186 HB-vaccinated infants born to HBsAg-positive mothers were included in the study. Serological tests for HBV markers were performed using commercial ELISA kits. Real-time quantitative PCR and nested PCR were used to detect HBV DNA. PCR products of the C and pre-S/S regions were sequenced and analyzed.

Results

1.61% (3/186) infants were HBsAg positive, and 4.92% (9/183) infants were considered as occult infection. The viral load of mothers was associated with occult infection (P = 0.020). Incomplete three-dose injections of HB vaccine was associated with HBV infection (P = 0.022). Six OBI infants were positive for anti-HBs, but their titers were not greater than 100 mIU/mL. Seven isolated HBV pre-S/S sequences were obtained from nine OBI infants. Three of the sequences were genotype C, and four of the sequences were genotype C/D. Escape mutation S143L was found in the four sequences of genotype C/D. All seven sequences lacked G145R and other escape mutation in S region.

Conclusions

Occult HBV infection was detected in anti-HBs positive infants born to HBsAg-positive mothers in China. Occult infection was associated with absent anti-HBs or with low anti-HBs level, high maternal viral loads and escape mutations in the S gene.

Treatment of children with chronic viral hepatitis: what is available and what is in store

BACKGROUND

At present, therapy of children with chronic hepatitis B and C is still based on few drugs, all burdened by a series of side-effects, unsatisfactory serum conversion rates, and/or drug-resistance. Moreover, selection of subjects to treat with conventional therapies is not univocal, especially during the pediatric age when the disease course is often mild with significant spontaneous seroconversion rate. Our review deals with pros and cons points when a physician decides to design a drug therapy for a child with chronic viral hepatitis, and different possible therapeutic opportunities.

METHODS

A literature search was performed through PubMed. The newest articles, reviews, systematic reviews, and guidelines were included in this review.

RESULTS

The management of children with viral hepatitis is still controversial over whom and when to treat and the use of drug(s). Novel therapeutic strategies have been evaluated only in clinical and preclinical trials involving, for instance, "therapeutic" vaccines. The data on safety and effectiveness of new drugs are also reviewed.

CONCLUSION

The results of reported studies confirmed that at least some of the new drugs, with greater efficacy and/or minor side-effects, will be used clinically.

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.

Differential plasma microRNA profiles in HBeAg positive and HBeAg negative children with chronic hepatitis B

BACKGROUND AND AIM

Children chronically infected with hepatitis B virus (HBV) are at high risk of progressive liver disease. However, no treatment is available that is consistently effective in curing chronic hepatitis B (CHB) in children. Improved understanding of the natural course of disease is warranted. Identification of specific microRNA (miRNA) profiles in children chronically infected with HBV may provide insight into the pathogenesis of CHB and lead to advances in the management of children with CHB.

PATIENTS AND METHODS

MiRNA PCR panels were employed to screen plasma levels of 739 miRNAs in pooled samples from HBeAg positive, HBeAg negative, and healthy children. The three groups' plasma miRNA profiles were compared, and aberrantly expressed miRNAs were identified. The identified miRNAs were then validated. Individual RT-qPCRs were performed on plasma from 34 HBeAg positive, 26 HBeAg negative, and 60 healthy children.

RESULTS

A panel of 16 plasma miRNAs were identified as aberrantly expressed in HBeAg positive and HBeAg negative children (p<0.001). Levels of all of the miRNAs were upregulated in HBeAg positive children compared with in HBeAg negative children. A positive correlation was furthermore found between plasma levels of the identified miRNAs and HBV DNA (p<0.001).

CONCLUSION

We are the first to investigate the plasma miRNA profile of children chronically infected with HBV. Our data indicates the existence of a relationship between abundance of circulating miRNAs and immunological stages in the natural course of disease. Certain miRNAs may contribute to the establishment and maintenance of CHB in children. Further studies are warranted to advance understanding of miRNAs in the pathogenesis of CHB, hopefully leading to the identification of future therapeutic targets.