Viremia profiles in children with chronic hepatitis B virus infection and spontaneous e antigen seroconversion

Current treatments for patients with HBeAg-positive chronic hepatitis B virus infection: a comparison focusing on HBeAg seroconversion

HBeAg seroconversion, in association with undetectable levels of hepatitis B virus DNA as determined by polymerase chain reaction, is an important goal in the treatment of patients with HBeAg-positive chronic hepatitis B (CHB). Achievement of sustained HBeAg seroconversion at an early age (<40 years) is associated with a reduced incidence of hepatic complications, increased rates of HBsAg loss and seroconversion and improved survival rates, whether the seroconversion is spontaneous or treatment induced. Patients with HBeAg-positive CHB who achieve sustained HBeAg seroconversion and complete 6-12 months of consolidation therapy are eligible for stopping therapy. In randomized clinical studies involving patients with HBeAg-positive CHB, treatment with pegylated interferon (PegIFN)-alpha is associated with higher and more durable HBeAg seroconversion rates than are lamivudine and adefovir. More recently, newer generation oral nucleos(t)ide analogs (NAs) have become available. These include entecavir, telbivudine and tenofovir, and they demonstrate superior antiviral potency and efficacy. This review examines the importance of HBeAg seroconversion as an end point for therapy in the treatment of patients with HBeAg-positive CHB, and examines the rates and durability of HBeAg seroconversion with PegIFN and oral NA therapy. The mechanisms for enhanced HBeAg seroconversion rates with new-generation NAs are also discussed.

Effect of puberty onset on spontaneous hepatitis B virus e antigen seroconversion in men

BACKGROUND

Male predominance is a remarkable phenomenon in hepatitis B virus (HBV)-related liver disease. This study elucidated the effects of puberty on spontaneous hepatitis B virus e antigen (HBeAg) seroconversion in boys.

METHODS

One-hundred HBeAg-positive chronic HBV-infected males recruited at younger than 10 years of age who had been followed for >10 years were selected randomly from our long-term followed cohort into this study. Serum testosterone levels, androgen receptor exon-1 CAG repeat number and steroid 5alpha reductase type II (SRD5A2, valine vs leucine alleles) polymorphism were determined. Serial clinical data, HBV genotype, and spontaneous HBeAg seroconversion age were also analyzed.

RESULTS

Seventy-two subjects had spontaneous HBeAg seroconversion during the follow-up period. Subjects with serum testosterone levels > or =2.5 ng/mL at 15 years old (earlier-onset puberty, n = 87) had earlier HBeAg seroconversion (median age, 13.2 vs 22.5 years; hazard ratio = 2.95; P = .005), higher peak alanine aminotransferase levels when HBeAg positive (305.7 +/- 372.7 vs 154.8 +/- 126.0 IU/L; P = .006), and a greater HBV viral load reduction from 10 to 20 years of age (1.6 +/- 2.4 vs 0.2 +/- 1.4 log10 copies/mL; P = .009) than those with serum testosterone levels <2.5 ng/mL (later-onset puberty, n = 13). Valine allele carrier at the SRD5A2 V89L polymorphism was also associated with earlier spontaneous HBeAg seroconversion (median age, 11.7 vs 18.7 years; hazard ratio = 1.88; P = .028).

CONCLUSION

Earlier-onset puberty and increased SRD5A2 enzyme activity are associated with earlier HBeAg seroconversion, higher serum alanine aminotransferase levels, and a greater HBV viral load decrement in chronic HBV infected males.

Age-specific prognosis following spontaneous hepatitis B e antigen seroconversion in chronic hepatitis B

Hepatitis B e antigen (HBeAg) seroconversion in chronic hepatitis B virus infection confers a favorable prognosis, but untoward outcomes may develop in some patients. The impact of the age of HBeAg seroconversion on prognosis is not clearly known. HBeAg-positive patients with biopsy-proven chronic hepatitis B were followed up long-term. Follow-up studies included liver biochemistry, alpha-fetoprotein, and ultrasonography every 3 to 6 months or more frequently if clinically indicated. Of the patients who underwent spontaneous HBeAg seroconversion, the incidences of HBeAg-negative hepatitis, cirrhosis, hepatocellular carcinoma (HCC), and hepatitis B surface antigen seroclearance were compared between patient groups with different ages at the time of HBeAg seroconversion using Kaplan-Meier survival analysis and Poisson regression model. Spontaneous HBeAg seroconversion was documented in 508 patients. Of the 483 patients who had no evidence of cirrhosis or HCC at the time of HBeAg seroconversion, HBeAg seroconversion occurred before age 30 in 218 patients (group A), between age 31 and 40 in 199 patients (group B), and after age 40 in 66 patients (group C). The 15-year cumulative incidences of HBeAg-negative hepatitis, cirrhosis, and HCC increased with increasing age of HBeAg seroconversion, the lowest being in group A (31.2%, 3.7%, and 2.1%, respectively) and highest being in group C (66.7% [P < 0.0001], 42.9% [P <0.0001], and 7.7% [P = 0.29], respectively). The hazard ratio of HBeAg-negative hepatitis, cirrhosis, and HCC was 2.95, 17.6, and 5.22, respectively, in group C compared with group A.

CONCLUSION

Patients with HBeAg seroconversion before age 30 have excellent prognosis, whereas patients with delayed HBeAg seroconversion after age 40 have significantly higher incidences of HBeAg-negative hepatitis, cirrhosis, and HCC.

Lower baseline ALT cut-off values and HBV DNA levels better differentiate HBeAg- chronic hepatitis B patients from inactive chronic carriers

AIM

To determine whether new cut-off values for alanine aminotransferase (ALT) and baseline hepatitis B virus (HBV) DNA levels better differentiate HBeAg(-) chronic hepatitis B (CHB) patients from inactive chronic carriers.

METHODS

Ninety-one patients [32 HBeAg(+) CHB, 19 inactive carriers and 40 HBeAg(-) CHB] were followed up for 2 years and were tested for HBV DNA levels by a PCR-based assay. ALT was tested twice during the last 6 mo using new cut-off values: ULN (upper limit of normal) 30 IU/L for males, 19 IU/L for females. Diagnostic accuracy, sensitivity, specificity, positive and negative predictive values were calculated by discriminant analysis.

RESULTS

When using the revised ALT cut-off values, the lowest optimal HBV DNA level that differentiated HBeAg(-) CHB patients from inactive carriers was 50 000 copies/mL. The diagnostic accuracy of HBV DNA to determine inactive carriers with a cut-off of 50 000 copies/mL was similar to the previously recommended cut-off of 100 000 copies/mL (91%). HBV DNA levels were lower than the cut-off value in 95% of inactive carriers and in 28% of HBeAg(-) CHB patients. With ALT < 30 IU/L in men and < 19 IU/L in women and HBV DNA levels < 100 000 copies/mL, the risk of CHB is 5%. On the other hand, if ALT values were > 30 IU in men and > 19 IU in women and baseline HBV DNA levels were > 100 000 copies/mL, the risk is 86%.

CONCLUSION

New cut-off values for ALT together with HBV DNA levels proposed by AASLD (American Association for the Study of Liver Diseases) and NIH (National Institute of Health) consensus seem appropriate to characterize inactive carriers.

Chronic hepatitis B and C infection in children in New South Wales

OBJECTIVE

To characterise epidemiological, clinical and laboratory features of children in New South Wales with chronic hepatitis B (HBV) or C (HCV) infections.

DESIGN AND SETTING

Retrospective record review of epidemiological, clinical, laboratory, liver biopsy and treatment data for children (aged < 18 years) referred to tertiary referral paediatric and refugee clinics in NSW with chronic HBV or HCV during 2000-2007; and comparison with NSW Health notification data for the same period.

MAIN OUTCOME MEASURES

Numbers and characteristics of referred children with HBV and HCV, and notifications to NSW Health.

RESULTS

During 2000-2007, 79 children with chronic HBV and 29 with HCV infection were referred to specialist clinics, while 930 children with HBV and 777 with HCV infection were reported to NSW Health. Most of the referred children with HBV were born overseas, while most with HCV were born in Australia to mothers with a history of intravenous drug use. Of the 79 HBV-infected children, 56 were e-antigen positive. Most HCV-infected children (23/29) had alanine aminotransferase levels < or = 2 times the upper limit of normal, and more than half of those who had genotype determined had type 2 or 3. Fibrosis was evident in liver biopsies performed for both HBV and HCV.

CONCLUSIONS

Although advanced liver disease was uncommon in children referred with HBV or HCV infection, a large number of infected children in NSW were not referred for specialist medical care, indicating that opportunities to intervene early in the natural history of these infections, particularly HCV, are being missed.

Hepatitis B virus DNA levels and outcomes in chronic hepatitis B

Serum hepatitis B virus (HBV) DNA levels can fluctuate markedly during the course of chronic HBV infection. Both case-control and cohort studies have shown a significant, dose-response association between serum HBV DNA levels measured at the time of initial evaluation and the subsequent risk of cirrhosis. A similar direct relationship has been shown for the risk of hepatocellular carcinoma (HCC) in cross-sectional, case-control, and cohort studies. Interventional studies have shown a strong correlation between the indices of disease activity seen on liver biopsy and levels of serum HBV DNA. These studies have also shown that reduction in HBV DNA levels correlate strongly with improvements in liver histology. For patients with HCC, prognosis (including risk of death, metastasis, and recurrence following surgery) is worse with higher serum HBV DNA levels. The preponderance of the evidence in the published literature demonstrates that serum HBV DNA level is an important and independent risk factor for disease progression in chronic hepatitis B. The relative importance of serial HBV DNA measurements, the loss of hepatitis B e and surface antigens, as well as the emergence of HBV mutants in the progression of chronic hepatitis B, especially in young patients, is an important need for future research.

Long-term efficacy of plasma-derived and recombinant hepatitis B vaccines in a rural township of Central Taiwan

AIMS

To assess the differences of long-term efficacy between plasma-derived and recombinant hepatitis B virus (HBV) vaccines and the effectiveness of catch-up vaccination in adolescents with undetectable anti-HBs.

METHODS

Before 1992, infants born in Taiwan were immunized using plasma-derived HB vaccine, and thereafter, by using recombinant HB vaccine. From the only junior middle school of a rural township in central-southern Taiwan, 1788 (93.7%) students from five cross-sectional screenings, grouping into three birth cohorts (Group I: born during 1984-1986, II: 1986-1992 and III: 1992-1995), were enrolled for checking HBsAg, anti-HBs and anti-HBc. Students with undetectable HBsAg and anti-HBs underwent a booster dose (2.5ug) of recombinant HB vaccine (Engerix-B; GlaxoSmithKline, Rixensart, Belgium) and had anti-HBs re-checked 3 weeks later. Individuals who had remained undetectable for anti-HBs completed the other two doses of HB vaccines at 1 and 6 months later.

RESULTS

The prevalence of HBsAg (11.4, 5.4 and 1.2%), anti-HBs (64.5, 44.1 and 36.0%) and anti-HBc (29.5, 12.5 and 4.4%) decreased from Group I to III (P<0.001 for trends). After a booster dose, the positive rates of anti-HBs increased up to 80.5% (16% increase) in Group I, 81.0% (36.9% increase) in Group II, and 94.4% (58.4% increase) in Group III. The percentages of anamnestic response increased with a trend (P<0.001). A total of 110 non-responders completed 3 doses of catch-up HB vaccination, but 3 cases (2.7%) of Group II, evoked primary vaccination response.

CONCLUSION

Recombinant vaccine showed predominant disappearance rate (62.7%) of anti-HBs 12-15 years after vaccination, but provided better anamnestic response after a booster dose. It also showed high success rate (97.3%) in catch-up vaccination in adolescents.

Hepatitis B virus infection

Since the introduction of the hepatitis B vaccine and other preventive measures, the worldwide prevalence of hepatitis B infection has fallen. However, chronic infection remains a challenging global health problem, with more than 350 million people chronically infected and at risk of hepatic decompensation, cirrhosis, and hepatocellular carcinoma. An improved understanding of hepatitis B virology, immunology, and the natural course of chronic infection, has identified hepatitis B virus replication as the key driver of immune-mediated liver injury and disease progression. The approval of potent oral antiviral agents has revolutionised hepatitis B treatment since 1998. Conventional and pegylated interferon alfa and nucleoside and nucleotide analogues are widely authorised treatments, and monotherapy with these drugs greatly suppresses virus replication, reduces hepatitis activity, and halts disease progression. However, hepatitis B virus is rarely eliminated, and drug resistance is a major drawback during long term therapy. The development of new drugs and strategies is needed to improve treatment outcomes.

High-titer antibody to hepatitis B surface antigen before liver transplantation can prevent de novo hepatitis B infection

OBJECTIVE

De novo hepatitis B virus (HBV) infection is defined as infection occurring in HBV surface antigen (HBsAg)-negative patients who become HbsAg positive after organ transplantation. We assessed the incidence and risk factors of de novo HBV infection in pediatric liver transplant recipients.

PATIENTS AND METHODS

From 1996 to 2006, 71 Taiwanese children with non-HBV-related liver diseases underwent orthotopic liver transplantation (OLT) at the National Taiwan University Hospital. All of the surviving recipients were tested regularly for liver function, serum levels of immunosuppressant, HBsAg, titers of antibodies to hepatitis B surface antigen (anti-HBs), antibodies to hepatitis B core antigen (anti-HBc), and antibodies to hepatitis C virus (anti-HCV). HBV vaccination histories and the anti-HBs titers before OLT were recorded. No regular prophylaxis was given.

RESULTS

Fifty-nine patients (33 girls and 26 boys) were followed up for a median of 4.4 years (range 1.0-10.0). Of those, 36 (61.0%) received allografts from anti-HBc-positive and HBsAg-negative donors. De novo HBV infection was found in 9 (15.3%) patients after OLT, 8 of whom received allografts from HBsAg-negative and anti-HBc-positive donors. Forty-eight (81.4%) patients received 3 or more doses of HBV vaccine before OLT. Pre-OLT anti-HBs titers were available for 49 recipients. Of the 9 de novo HBV-infected recipients, 8 had anti-HBs titers <200 mIU/mL. No graft loss or fulminant hepatitis was noted.

CONCLUSIONS

In the absence of adequate prophylaxis, the incidence of de novo HBV infection in pediatric OLT recipients is 15.3%. An anti-HBs titer of >200 mIU/mL before OLT may be sufficient to prevent de novo HBV infection in HBsAg-negative recipients.

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Viral hepatocarcinogenesis: from infection to cancer

Hepatocellular carcinoma (HCC) is a worldwide health issue that has started receiving attention but is still poorly understood. However, the hepatitis B virus (HBV) and the hepatitis C virus (HCV) are known to be two major causative agents of HCC. They differ in their modes of infection, their treatment options, their genomes and their carcinogenic abilities. However, both share a link with HCC through alterations of the host genome. In order to continue in our search for the mechanisms behind viral hepatocarcinogenesis, the individual entities (HBV, HCV, HCC and host), their natural history, treatment options and genomic properties must be further understood. Additionally, an understanding of the genomics, the link between the entities, is crucial for the success of the ongoing search for therapeutic options for HCC. Similar to most types of cancer, hepatocarcinogenesis is a multistep process involving different genetic alterations that ultimately lead to malignant transformation of the hepatocyte. As technology advances and research continues, the genetic changes and influences among these entities will prove essential to improved diagnostic and therapeutic options. It remains a challenge to provide a clear picture of the connection between virus and cancer. We review (i) the epidemiological link between HBV/HCV infection to HCC; (ii) prevention and control of chronic hepatitis B or C in reducing HCC risk; and (iii) genetic characters of viruses and hosts and the mechanisms associated with HCC susceptibilities, with the intention of providing a direction for future research and treatment.

Natural history of chronic hepatitis B: special emphasis on disease progression and prognostic factors

The natural history of chronic hepatitis B virus (HBV) infection and disease is complex and highly variable. We review the natural history of chronic hepatitis B with emphasis on the rates of disease progression and factors influencing the course of the liver disease. Chronic hepatitis B is characterized by an early replicative phase (HBeAg positive chronic hepatitis) and a late low or non-replication phase with HBeAg seroconversion and liver disease remission (inactive carrier state). Most patients become inactive carriers after spontaneous HBeAg seroconversion with good prognosis, but progression to HBeAg negative chronic hepatitis due to HBV variants not expressing HBeAg occurs at a rate of 1-3 per 100 person years following HBeAg seroconversion. The incidence of cirrhosis appears to be about 2-fold higher in HBeAg negative compared to HBeAg positive chronic hepatitis. In the cirrhotic patient the 5-year cumulative risk of developing hepatocellular carcinoma is 17% in East Asia and 10% in the Western Europe and the United States and the 5-year liver related death rate is 15% in Europe and 14% in East Asia. There is a growing understanding of viral, host and environmental factors influencing disease progression, which ultimately could improve the management of chronic hepatitis B.