Update on prevention and treatment of viral hepatitis in children

Hepatitis A virus infections, immunisations and demographic determinants in children and adolescents, Germany

Hepatitis A is a vaccine-preventable disease with a global distribution. It predominantly occurs in regions with inadequate living conditions, but also affects populations in industrialised countries. Children are frequently involved in the transmission of hepatitis A virus (HAV) and thus play a central role in the epidemiology of hepatitis A. Here, we investigated HAV infections, immunisations, and associated demographic determinants in a nationwide, population-based, cross-sectional survey conducted in Germany from 2003-2006. Out of 17,640 children and adolescents, complete data sets (HAV serology, demographic information and vaccination card) were available for 12,249 (69%), all aged 3-17 years. We found protective antibody levels (>=20 IU/L) in 1,755 (14%) individuals, 1,395 (11%) were vaccinated against hepatitis A, 360 (3%) individuals were HAV seropositive without prior hepatitis A vaccination, thus indicating a previous HAV infection. Antibody prevalence (attributable to vaccination or infection) increased significantly with age. Multivariate logistic regression revealed that predominantly children and adolescents with migration background-even if they were born in Germany-are affected by HAV infections. Our results provide a rationale to emphasise existing vaccination recommendations and, moreover, to consider additional groups with a higher risk of infection for targeted vaccination, especially children with a migration background.

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.

Factors influencing clinical course and histological findings in children with chronic hepatitis B

INTRODUCTION

Although the clinical course of chronic hepatitis B (CHB) is relatively mild in a majority of children, a certain proportion of patients develops chronic liver disease that finally results in serious liver injury. Reports regarding clinical outcome of infection are scarce.

OBJECTIVE

The aim of this study was to assess inflammatory activity, fibrosis, and their correlation to clinical data in children with CHB before antiviral treatment.

MATERIALS AND METHODS

The study included 200 children, aged 1.5-18 years (mean 7.49+/-4.01 years), with CHB hospitalized before liver biopsy between 1992 and 2003. History and clinical data were analyzed. Histopathological assessment was based on the modified Knodell system. Statistical analysis was performed, and results with P<0.05 were considered significant.

RESULTS

Necroinflammatory activity was found to be mild in 115 children and moderate in 44. Ninety-three children had minimal fibrosis (S1), 62 children - S2, and the remaining 8 - S3-S4. Alanine aminotransferase (ALT) activity was proportional to staging (Kruskall-Wallis test H=10.84, P=0.028) and was significantly higher in the children with staging >or=S2, P=0.0008. Spontaneous hepatitis B early antigen seroconversion occurred in 30/200 children (15%) and was related to the shorter length of infection, P=0.008.

CONCLUSION

Intensity of liver injury in children with CHB varies from minimal to marked necroinflammatory activity and fibrosis varies from none to advanced. Progression of liver fibrosis seems to be proportional to the age at infection. ALT activity appears to be higher in the children with significant (S2-S4) fibrosis. Spontaneous hepatitis B early antigen seroconversion is apparently related to the shorter length of infection and higher ALT activity.

The pharmacokinetics and safety of adefovir dipivoxil in children and adolescents with chronic hepatitis B virus infection

There is a continued need for safe and effective treatments for children and adolescents with chronic hepatitis B. Adefovir dipivoxil (ADV) is a licensed treatment for chronic hepatitis B in adults. This study was designed to characterize the pharmacokinetic profile of adefovir following the administration of 0.14 mg/kg and 0.3 mg/kg of ADV (oral solution) in children aged 2 to 11 years and of ADV 10 mg in adolescents aged 12 to 17 years. Forty-five subjects were included in the pharmacokinetic and safety evaluations. Adefovir was rapidly absorbed. Adefovir levels rose rapidly in the first hour and then declined in a biphasic manner. Dose-proportional pharmacokinetics was observed in the 0.14-mg/kg and 0.3-mg/kg groups. The 0.3-mg/kg dose in children aged 2 to 6 and the 10-mg dose in adolescents resulted in exposures that were comparable to those seen previously in adults given ADV 10 mg. Adefovir dipivoxil was well tolerated at the doses evaluated in this study. Adverse events were generally mild and reported as being unrelated to study medication. There was 1 serious adverse event reported that was not related to study medication. No patient discontinued the study prematurely due to an adverse event related to the study drug.

Long-term outcome in children with chronic hepatitis B: a 24-year observation period

BACKGROUND

Chronic hepatitis B seems to manifest as mild disease in children and young adults. However, data regarding the long-term course of hepatitis B in untreated and interferon-treated children are still scarce. This study investigates the long-term outcome of disease in a large series of untreated and treated children with hepatitis B virus (HBV) infection.

METHODS

Clinical, biochemical, virological, and histological features were evaluated in children (age range, 2-18 years) with chronic HBV infection who did not have concomitant chronic systemic diseases other than HBV infection and who were admitted to the liver unit in the Department of Pediatrics at University "Frederico II" (Naples, Italy) during the period 1981-2005.

RESULTS

One hundred eight consecutive patients observed for up to 24 years were studied. During the observation period, 67 children remained untreated, and 41 were treated with interferon-alpha. After a median period of observation of 12.1 years (range, 5-23 years), hepatitis B early antigen loss and serum HBV DNA clearance occurred in 43 untreated patients (69.3%) who were hepatitis B early antigen positive at study entry and in 33 treated children (80%; the P value is not statistically significant). In addition, 6 untreated patients (9.7%) and 4 treated patients (9.7%) became anti-HBs [corrected] positive at the end of the follow-up period. Histological assessment, evaluated for 57 children, showed mild-to-moderate disease in 91.2% of cases of HBV infection. No patient developed end-stage liver disease or hepatocellular carcinoma.

CONCLUSIONS

Children with chronic HBV infection are symptom free, with morphologically mild liver disease. Considering that the overall long-term outcomes did not differ between treated and untreated patients, the real impact of therapy on the long-term course of HBV infection remains to be established. Additional studies are needed to confirm our conclusions.

Characterization of HCV strains in an oncohematological pediatric department reveals little horizontal transmission but multiple introductions by un-screened blood products in the past

Because several children were found infected with hepatitis C virus (HCV) at a pediatric oncohematological department in Vilnius, 474 children were tested for anti-HCV. Fifty-eight percent of 96 children treated with blood and plasma products manufactured before the introduction of anti-HCV screening of blood in Lithuania in 1994 were positive for anti-HCV versus 3.4% of those treated after 1994. The possible route of transmission for 45 of these was investigated by phylogenetic analyses within the NS5B region. Children treated before 1995 were infected with a multiplicity of strains of different subtypes, predominantly 1b found in 21 cases, 3a in 5 cases, 2 in 3 cases, 1a in 1 case, and not subtypeable genotype 1 strains in 2 cases. Children who had received blood products after 1994 were infected with only two subtypes, 1b in six and 3a in seven. Genetic analysis showed multiple introductions of HCV before 1995 and that horizontal spread between patients had occurred only to a minor extent at the department. However, two transmission chains involved children treated before 1995. Another chain involved five children treated after 1994. Since the most important risk factor for acquiring hepatitis C was blood products manufactured before the introduction of donor screening for anti-HCV, the spread between children would not have been revealed without molecular tools. These and the background strains provide the first reported sequence data on Lithuanian HCV strains. In general, these were shown to form autochthonous clades, except the 3a strains that were related to strains from the former USSR.

Epidemiology and management of infectious diseases in international adoptees

International adoptees represent a group of children with unique health care needs. Data from published studies, along with the recent experience of the Yale International Adoption Clinic, suggest that the risk of serious infections in adoptees is low, although infections associated with institutionalization still occur commonly. Interpretation of these data must be undertaken with caution, however, since many, if not most, international adoptees are not evaluated in specialty clinics. Thus, prospective studies designed to minimize selection and referral bias are needed in order to accurately define the risk of infectious and noninfectious diseases in all international adoptees.

Risk of hepatocellular carcinoma in liver mitochondrial respiratory chain disorders

Mitochondrial respiratory chain disorders (MRCD) are a large group of disorders that can affect any organ besides muscles or the central nervous system. We report two children who presented with neonatal cholestasis and progressive cirrhosis, who subsequently developed hepatocellular carcinoma (HCC). This suggests a particular risk of degeneration in these patients and the importance of a regular screening for secondary liver cancer. Suggestion of HCC should lead to early liver transplantation, which was successful without tumor recurrence in the two patients.

Chronic hepatitis B infection: long term comparison of children receiving interferon alpha and untreated controls

OBJECTIVES

To investigate the virological outcome of chronic hepatitis B (CH-B) in children who received interferon alpha (IFN) compared with no treatment.

METHODS

Seventy-four children with CH-B (median age, 6.1 years; 44 boys) selected from a cohort of 158 cases were included and divided into two groups: IFN-treated (n = 37) and control (n = 37). The controls were matched with the treated children by baseline alanine aminotransferase (ALT) levels, sex and age. The Kaplan-Meier method was performed to estimate the time to clearance of hepatitis B e antigen (HbeAg) and hepatitis B surface antigen (HbsAg).

RESULTS

Mean duration of follow-up was comparable in two groups (5.2 +/- 3.8 years in treatment group versus 5.2 +/- 3.7 years in control group, NS). HBeAg and HBsAg loss occurred in 20 (54.1%) and three treated children versus 13 (35.1%) and one untreated children (NS), respectively. The 7-year cumulative HBeAg and HBsAg clearance rates were 47.5% and 8.9% after the first visit in the treatment group versus 33.5% and 4.0% in untreated children (NS), respectively. Elevated baseline ALT (two times upper limit of normal) had a significant effect on the long-term cumulative rate of HBeAg seroconversion in treated patients (P = 0.01) but not in the untreated group.

CONCLUSIONS

These findings show that the overall long-term virological outcome does not differ significantly between IFN-treated and untreated children but that a significant benefit of treatment on the long term rate of HBeAg seroconversion is obtained in children with higher baseline ALT levels.

Low birth weight: a possible risk factor also for liver diseases in adult life?

Birth weight is a popular topic, because it is precisely recorded, a major determinant of infant survival, associated with infant mortality, and health outcomes later in life. Low birth weight (LBW) is a predisposing factor for metabolic abnormalities such as atherosclerosis, renal disease, non-insulin diabetes mellitus, asthma, low IQ, hypertension, obesity, psychological distress. They have all been reported to be more common among those who were small at birth. Due to lack of studies suggesting a linkage between LBW and diseases of liver; evidences, which support the hypothesis on the creation of a link between LBW, an indicator of unfavourable intrauterine environment, and liver diseases emerging in the adult life, and possible direct associations of LBW with liver diseases, e.g., hepatitis, non-alcoholic fatty liver disease, cirrhosis, hepatoblastoma, or hepatocellular carcinoma were discussed. The associations between LBW and hepatitis vaccination as well as paediatric parental nutrition were also noted.

Virus genotype 1b and long-term response to interferon alpha monotherapy in children with chronic hepatitis C

Interferon alpha (IFN-alpha) remains the basic modality in the treatment of chronic hepatitis C in children, but the effects of therapy are still unsatisfactory. The aim of this study was to evaluate parameters linked to IFN-alpha response within a 2-year period. Human C virus (HCV) infected children (n=34) were subdivided into IFN-treated (n=20) and IFN-untreated (n=14 control) groups. The IFN-treated group received a dosage 3 MU of IFN-alpha three times a week for 24 weeks. Liver biopsy was performed in all IFN-treated children and the HCV genotype was determined before the start of the study. Patients were sequentially screened for alanine transaminase (ALT) activity and tested for the presence of HCV-RNA in serum. All patients had either mild persistent or moderate active hepatitis, which was diagnosed from the liver biopsy. In the IFN-treated group ALT normalisation was observed by the end of treatment in 9/20 patients, but after 6 months 10 patients (50%) had sustained ALT normalisation and in 4 of them the virus was eliminated. They continued to show these features up to the end of the observation period (2 years). Eighteen out of 24 children tested had 1b genotype of virus. Out of 10 responders, all patients who were clear of HCV had the 1b genotype. The median age of responders (6.0, range 3.8-16) was significantly lower than non-responders (14.0, range 4-15) In the control group none of the children were clear of HCV-RNA.

CONCLUSION

The negative predictive effect of HCV genotype 1b in the course of IFN-alpha treatment may be not valid in children and other features have to be taken into account in the assessment of the efficacy of therapy.

Drug treatment of pediatric chronic hepatitis B

Children with chronic hepatitis B are at risk of developing long-term complications such as cirrhosis and hepatocarcinoma. It is estimated that half to two-thirds of affected children will clear the hepatitis B e antigen (HBeAg) naturally before reaching adulthood. As in adults, treatments in children accelerate the virological response (DNA negativity and HBeAg loss, with anti-HBe seroconversion), which is associated with normalization of transaminase levels. Treatments also favor subsequent loss of hepatitis B surface antigen (HbsAg), the ultimate goal for minimizing long-term consequences. Interferon-alpha was the first approved treatment for pediatric chronic hepatitis B, and was shown to promote DNA negativity and HBeAg loss in 26% of treated patients (6 MU/m(2) body surface area for 6 months) at 1 year and 33% at 18 months (versus 11% in controls). 10% of treated patients also lost HBsAg. Adverse effects mainly included fever, flu-like symptoms and growth impairment during the treatment phase. Nucleotide analogs have now emerged as promising alternatives for the treatment of chronic hepatitis B. Lamivudine dose-ranging studies showed a higher clearance in children, and the optimal dosage was established to be 3 mg/kg once daily in children up to 12 years of age. Efficacy trials showed complete virological response (HBeAg loss and DNA negativity) in 23% of all treated patients after 1 year, and in 34% of patients with initial transaminase levels >2 x the upper limit of normal. Lamivudine resistance due to mutant/variant viruses is observed in 19% of children after 1 year, a figure that may increase by an average of 20% per year. Other nucleotide analogs, such as adefovir, will soon be tested in children, and have shown promising results in adults without so far demonstrating viral resistance. Finally, therapeutic vaccines aiming to induce a cellular immune response towards hepatitis B antigens are being tested in adults, but no clinical benefit has so far been established.