Long-term follow-up of hepatitis B virus carrier infants

Clearance of Hepatitis B e Antigen in Untreated Chronic Hepatitis B Virus Infection: A Systematic Review and Meta-analysis

BACKGROUND

In people with hepatitis B virus (HBV) infection, persistence of hepatitis B e antigen (HBeAg) is associated with clinical progression and need for treatment. HBeAg loss represents partial immune control and is a critical event in the natural history of chronic HBV.

METHODS

We conducted a systematic review and meta-analysis of cohort studies that report HBeAg loss among people with untreated chronic HBV. We evaluated HBeAg loss using a random-effects model and conducted subanalysis on region.

RESULTS

We screened 10 560 publications, performed 196 full-text analyses, and included 26 studies for meta-analysis. The pooled rate of HBeAg loss was 6.46/100 person-years (PYs) (95% confidence interval, 5.17-8.08). Meta-regression showed that older age of participants and studies in Europe were associated with higher rate of HBeAg loss. Rates per 100 PYs were 7.43 (95% confidence interval, 6.30-8.75; 1 study) in Africa, 3.24 (2.61--4.02; 1 study) in the Eastern Mediterranean, 13.67 (11.21-16.66; 4 studies) in Europe, 7.34 (4.61--11.70; 5 studies) in North America, and 5.53 (4.05--7.55; 15 studies) in the Western Pacific.

CONCLUSIONS

Spontaneous HBeAg loss occurs at a rate of 6.46/100 PYs. Variations by region and age group may reflect epidemiological, immunological, or HBV genotype-related differences.

New Strategies for Blood Donor Screening for Hepatitis B Virus

Serologic testing for hepatitis B virus (HBV) surface antigen (HBsAg) and antibody to HBV core antigen (anti-HBc) has historically been the foundation of blood screening, while HBV nucleic acid testing (NAT) was recently developed to detect HBsAg-negative, anti-HBc-negative blood units donated during early acute infection. Comparison data on seroconversion panels using HBsAg assays of varying sensitivities and pooled- or single-sample NAT, along with viral load estimates corresponding to HBsAg assay detection limits, have provided information on the theoretical benefits of NAT relative to HBsAg. Model-derived estimates have generally been predictive of the yields of DNA-positive, HBsAg-negative window period blood units detected in a number of studies from Europe, Japan, and the US. Studies indicate that the added benefit of pooled-sample NAT is relatively small in areas of low endemicity, with greater yields in areas highly endemic for HBV. Single-sample NAT would offer more significant early window period closure and could prevent a moderate number of residual HBV transmissions not detected by HBsAg assays; however, no fully automated single-sample HBV NAT systems are currently available.Even single-sample HBV NAT may not substitute for anti-HBc screening, as indicated by studies of donors with isolated anti-HBc who have extremely low DNA levels undetectable by standard single-sample NAT and who have been associated with transfusion-transmitted HBV. Moreover, HBsAg testing may still be needed even in the setting of combined anti-HBc and NAT screening. HBsAg-positive units from donors in the chronic stage of infection may contain very low or intermittently detectable DNA levels that single-sample NAT would miss. Although such donors are usually anti-HBc reactive and would be interdicted by anti-HBc screening, some lack anti-HBc. Extensive parallel testing will be needed to determine whether single-sample NAT in combination with anti-HBc might be sufficient to detect all the infectious donors currently interdicted by HBsAg testing. In countries that do not screen for anti-HBc, HBsAg testing would be the only means of detecting donations from chronically infected individuals with low/intermittently detectable DNA, since even single-donor NAT would not identify these potentially infectious blood units. In the future, the current fully automated HBsAg assays may incorporate significant sensitivity improvements, and automated single-sample HBV NAT may become a reality. Each country will need to develop its blood screening strategy based on HBV endemicity, yields of infectious units detected by different serologic/NAT screening methods, and cost effectiveness of test methods in ensuring blood safety.

Permanent loss of anti-HBc after reactivation of hepatitis B virus infection in an anti-HBs and anti-HBc-positive patient after allogeneic stem cell transplantation

BACKGROUND

Reactivation of a hepatitis B virus (HBV) infection after transplantation is associated with a high morbidity and mortality. HBV infections generally result in anti-HBc persisting lifelong.

CASE REPORT

A 44-year-old female presented 10 years after allogeneic stem cell transplantation with a chronic hepatitis B. The infection was reactivated from a resolved (anti-HBs and anti-HBc positive) HBV infection acquired some years prior to transplantation. Interestingly, she lost all antibodies to HBV including anti-HBc and is upto now anti-HBc negative. The sequence of the surface and the core gene did not reveal any escape mutations. Thus, the loss of anti-HBc might suggest an immunotolerance of the donor's immune system against HBcAg.

CONCLUSION

This data illustrate that an HBV infection might be reactivated despite high anti-HBs levels prior to transplantation. Furthermore, this is the first patient in which a complete loss of anti-HBc could be documented. Moreover, since anti-HBc is often used as a screening marker for HBV it should be kept in mind that anti-HBc negative patients with high viremic HBV infection may occur.

Natural history of hepatitis B in perinatally infected carriers

OBJECTIVES

To establish natural seroconversion rates and incidence of hepatic pathology in perinatally infected hepatitis B carriers.

METHODS

Seventy three perinatally infected hepatitis B carriers identified through maternal screening were evaluated. Fifty three were born to parents from the Indian subcontinent, nine were Oriental, six were Afro-Caribbean, and five were white. Median follow up was 10.24 (range 2.02-20.16) years.

RESULTS

Only three of the children followed up had cleared hepatitis B surface antigen during this period, and 30% of the children had seroconverted to anti-HBe. Seroconversions to anti-HBe were observed in Asian (18/50) and white (4/5) children, but not in Oriental or Afro-Caribbean children. More girls (40%) than boys (23%) had seroconverted, but the difference was not significant. All children were asymptomatic with normal physical examination, growth, and development. Almost half (48%) of the hepatitis B e antigen (HBeAg) positive children had normal hepatic transaminases and liver function. Thirty five liver biopsies were performed in children with active virus replication (HBeAg or hepatitis B virus DNA positive) who were being considered for antiviral treatment as part of a clinical trial and were scored using the Ishak method. Two thirds (62%) of the children had mild hepatitis, 60% had mild fibrosis, and 18% had moderate to severe fibrosis. There was a weak correlation between histological evidence of hepatitis and hepatic transaminase activity, implying that biochemical monitoring of hepatic disease activity may be ineffective.

CONCLUSIONS

These asymptomatic hepatitis B virus carrier children remain infectious in the medium to long term with notable liver pathology. They should receive antiviral treatment to reduce infectivity and to prevent further progression of liver disease. Hepatic transaminases alone are not a reliable marker of liver pathology, and liver histology is essential before consideration for antiviral treatment.

Structural and functional heterogeneity of naturally occurring hepatitis B virus variants

Most organisms have developed sophisticated machineries to preserve their genomic integrity. On the contrary hepatitis B virus (HBV), like a lot of other viruses can undergo rapid and drastic sequence changes, especially if the virus has to cope with natural or therapy induced antiviral mechanisms in the host. Here, we try to summarize possible implications for the molecular pathogenesis of HBV based on the extensive research on the genetic variants of HBV.

Outcome of chronic hepatitis B in Caucasian children during a 20-year observation period

BACKGROUND/AIMS

Chronic hepatitis B virus infection can lead to cirrhosis and hepatocellular carcinoma, particularly in men over 40 years of age and in areas where childhood-onset infection is common. The sequence of events from paediatric infection to severe disease in adults is only partially known. The aim of this study was to evaluate the evolution of chronic hepatitis B acquired in childhood during 20 years of follow-up.

PATIENTS

One hundred and eighty-five consecutive, otherwise healthy, Caucasian children were enrolled in Padua (Italy) and in Madrid (Spain) between 1975 and 1985, and followed for an average period of 13 years; 168 were hepatitis B e antigen (HBeAg) positive and five had cirrhosis.

RESULTS

Thirty patients received steroids or levamisole and 21 interferon, but treatment did not significantly influence HBeAg clearance. Overall, two (1.1%) children, with initial cirrhosis, developed hepatocellular carcinoma and the other three (1.6%) cirrhotic patients became asymptomatic carriers of infection after anti-HBe seroconversion and biochemical remission; 14 (7.5%) children maintained HBeAg positive hepatitis; 155 (83.8%) became asymptomatic carriers of infection after anti-HBe seroconversion and biochemical remission; six (3.2%) experienced reactivation of liver disease and viral replication after remission and five (2.7%) maintained biochemical features of liver damage after HBeAg clearance. Only 6% cleared hepatitis B surface antigen.

CONCLUSIONS

Even considering the bias of treatment, the large majority of Caucasian children with chronic hepatitis B became asymptomatic carriers of infection with normal alanine amino-transferase during the first 20 years of observation. Cirrhosis is an early, rare complication, and a risk factor for hepatocellular carcinoma. A subgroup of patients who experienced reactivation or maintained liver damage after HBeAg clearance seems to be at greater risk for disease progression during adult life.

Chronic viral hepatitis in childhood

In endemic areas infection with hepatitis B virus is a common cause of chronic liver disease in childhood. High levels of viral replication and mild ALT abnormalities are the rule in children infected perinatally and many of them are likely to maintain viral replication through their youth. Conversely about 90% of children infected later in life clear HBeAg and achieve sustained remission of liver disease before reaching adulthood. The eventual outcome of infection and disease in these patients remains unpredictable as reactivation of liver damage and viral replication may occur after several years of sustained remission. Cirrhosis is a rare and early complication of chronic HBV infection in children, and a risk factor for hepatocellular carcinoma. IFN therapy can accelerate HBV DNA clearance, improving the spontaneous anti-HBe seroconversion rate in Caucasian children by two to three times. Hepatitis delta is the most severe form of chronic viral hepatitis in childhood. Cirrhosis can be diagnosed in up to 26% of patients at presentation, and few cases respond to IFN therapy. Hepatitis C is relatively rare in children. Before the discovery of HCV, blood transfusions were the most common source of infection. Hepatitis C is usually a mild, asymptomatic disease in otherwise healthy children, but has a poor propensity to spontaneous remission over the years. For this reason, and based on the experience in adults, IFN treatment is now being evaluated.