Chronic hepatitis B in male and female children of HBsAg carrier mothers

The association between maternal hepatitis B e antigen status, as a proxy for perinatal transmission, and the risk of hepatitis B e antigenaemia in Gambian children

BACKGROUND

Early age at infection with hepatitis B virus (HBV) increases the risk of chronic HBV infection. In addition early age at infection may further increase the risk of persistent viral replication beyond its effect on chronicity. The effects of perinatal and early postnatal transmission on the risk of prolonged hepatitis B e antigenaemia in children with chronic HBV infection are not well documented in Africa. We examine these associations using maternal HBV sero-status and the number of HBV-positive older siblings as proxy measures for perinatal and early postnatal transmission, respectively.

METHODS

Hepatitis B e antigen (HBeAg)-positive mothers were identified in six population-based HBV sero-surveys conducted in The Gambia between 1986 and 1990. For every HBeAg-positive mother, a hepatitis B surface antigen (HBsAg)-positive HBeAg-negative mother and HBsAg-negative mother were randomly selected from the population surveyed. These mothers and their family members were tested for HBV sero-markers in a subsequent survey conducted between 1991 and 1993.

RESULTS

Thirty-eight HBeAg positive mothers and the same number of HBsAg-positive HBeAg-negative mothers and HBsAg-negative mothers participated in the study. Sixty-nine percent of their children also participated. There was a non-significant positive association between HBeAg prevalence in children and the number of HBeAg-positive older siblings (64.1%, 69.2% and 83.3% in children with 0, 1 and ≥2 HBeAg-positive older siblings, respectively). After adjusting for confounders, having an HBeAg-positive mother was a risk factor for HBeAg positivity in children carrying HBsAg (adjusted OR 4.5, 95% CI: 1.0-19.5, p = 0.04), whilst the number of HBeAg-positive older siblings was not.

CONCLUSIONS

Maternal HBeAg was associated with positive HBeAg in children with chronic HBV infection. This suggests that interrupting mother-to-infant transmission in sub-Saharan Africa might help reduce the burden of liver disease. A timely dose of HBV vaccine within 24 hours of birth, as recommended by WHO, should be implemented in sub-Saharan Africa.

Association of early age at establishment of chronic hepatitis B infection with persistent viral replication, liver cirrhosis and hepatocellular carcinoma: a systematic review

Age at infection with hepatitis B virus (HBV) is a known risk factor for chronic HBV infection. However, in addition, there is some evidence that early age at infection further increases the risk of primary liver cancer beyond its association with increased risk of chronic infection. This systematic review of observational studies assesses the association between age at initiation of chronic HBV infection and liver cirrhosis, hepatocellular carcinoma, and their predictors including indicators of ongoing viral replication and hepatic damage. The review includes birth order and maternal HBV serology as proxies for age at infection. Electronic searches in two English-language (Medline and Embase, until Jan 2012) and two Chinese-language (CNKI and SinoMed, until Sep 2012) databases without language restriction and manual search through reference lists identified 7,077 papers, of which 19 studies of 21 outcomes (8 primary liver cancer, 1 liver cirrhosis, 10 viral replication and 2 liver inflammation) are included. One study directly examined the age at infection in a longitudinal cohort, 12 assessed maternal sero-status and 6 investigated birth order. The direction of associations in all studies was in accordance with our hypothesis that earlier age at infection is associated with worse outcomes in addition to its effect of increasing the probability of chronic HBV infection. This has implications for the control of hepatitis B.

Does genotype predict response to treatment in children infected with hepatitis B perinatally?

HBV genotype may correlate with outcome and treatment response. Genotype has been compared with treatment response in children infected perinatally with hepatitis B following treatment with oral antiviral drugs (lamivudine or adefovir) or interferon (IFN) alone and with prednisolone priming (Pred/IFN). All children who took part in clinical trials in this unit since 1990 were included. Hepatitis B genotypes were determined by direct sequencing or using a commercial line probe assay (InnoLipa). Sixty-five children were included; 20 were treated with IFN; 19 with Pred/IFN; 22 with lamivudine and 7 with adefovir, some took part in more than one treatment study. 63 out of 65 children were clearly typed into single genotypes; 16, 7, 3, and 37 typing as A, B, C, and D respectively. The majority of South-Asian children had genotype D and European and Afro-Caribbean children were more likely to have genotype A. Treatment response (seroconversion from HBeAg to Anti-HBe) was better in children with genotypes A [n = 16] and D [n = 37] (55.5% and 48.7%), compared to those with B [n = 7] and C [n = 3] (12.5% and 0%) for all treatments. The response to interferon alone was better in children with genotype A compared to D (50% and 36%), but prednisolone priming improved the response so that there was no difference between genotypes A and D (66.7% and 70%). Assessment of genotype in children pre-treatment may provide a guide to potential response. The response to treatment by genotype should be evaluated in future clinical trials in children.

Profile of chronic hepatitis B virus in children in India: experience with 116 children

BACKGROUND

Hepatitis B virus (HBV) infection in children is mostly asymptomatic and therefore the disease burden is likely to be under appreciated. There is limited information on the profile of chronic HBV infection in children from the Indian subcontinent.

METHOD

In 116 (male:female 89:27) children, aged <15 years, with persistent HBsAg positivity for more than 6 months, a clinical, biochemical, virological and histological assessment was carried out.

RESULTS

At presentation, 21.6% of children were symptomatic, with icterus in 12%. Features of decompensation such as ascites (7%) and gastrointestinal (GI) bleed (5%) were noted uncommonly. Five (4.3%) children had hepatocellular carcinoma (HCC) at presentation. Elevated alanine aminotransferase (ALT) was observed in 76% of subjects (median 61; range 14-815). A significantly higher proportion of children with hepatitis B early antigen (HbeAg) positive status had higher histological activity index (HAI) (84% vs 16%, P < 0.001) and fibrosis score (80% vs 20%, P = 0.007). A strong positive correlation was noted between aspartate aminotransferase (AST), ALT, HBV-DNA and histological severity of the disease (HAI > or =4, fibrosis > or =2). Median HBV-DNA levels were significantly higher in the HBeAg positive compared to the HBeAg negative group (25.6 vs 0.7 pg/mL, P = 0.004). Seventy-four percent of the mothers had evidence of past or present HBV infection.

CONCLUSIONS

Majority of the children with chronic HBV infection are asymptomatic at presentation. HBeAg positive status reflects histologically more severe disease, and a higher level of HBV-DNA. Almost two-thirds of the children may have acquired their HBV infection perinataly.

Long-term follow-up of hepatitis B carrier children treated with interferon and prednisolone

The long-term outcome of treatment with Interferon Alpha 2B with and without Prednisolone priming in children infected perinatally with hepatitis B was reviewed. The group studied included 48 children (aged 2-16 years), who were HBe antigen and hepatitis B DNA positive between 1991 and 1993. Twenty children were randomized to a therapeutic trial at that time, and received Prednisolone in reducing doses for 6 weeks and Interferon for 16 weeks while 22 children were monitored without treatment for 12 months. Fourteen of the untreated group and 6 additional children later received treatment with Interferon alone (n = 20). Eight children for whom treatment was declined were followed long term. Median follow-up was 7.5 years (range 1.5-10.6). There was no significant effect of Interferon therapy on seroconversion with or without Prednisolone at 12 months post-treatment compared to untreated children. On longer term follow-up, the 5-year HBeAg to anti-HBe seroconversion percentages, estimated from Kaplan-Meier curves, were 54% for Prednisolone plus Interferon, 22% for Interferon alone, and 12% for untreated children. The median time to seroconversion was 3.9 years (range 0.4-8.2) and was shortest in those treated with Prednisolone plus Interferon. Children who had elevated hepatic transaminase enzymes prior to treatment or during Prednisolone priming had a better response. In contrast to many European studies, no child cleared HBsAg and produced anti-HBs. Treatment with Prednisolone priming and Interferon, improved both the time and rate of seroconversion compared to no treatment or Interferon alone, suggesting that this combination of drugs might have an immunomodulatory effect.

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.

Targeted hepatitis B vaccination--a cost effective immunisation strategy for the UK?

OBJECTIVE

To compare the potential cost effectiveness of vaccination against hepatitis B virus (HBV) targeted at genitourinary clinic (GU) attendees with that of universal infant vaccination.

DESIGN

A mathematical model of sexual and perinatal transmission of HBV was used to compare the effectiveness among heterosexual and homosexual populations of programmes of mass infant vaccination and targeted immunisation of genitourinary medicine (GU) clinic attendees. Each was applied to 90% of the eligible population with differing assumptions about rates of compliance and seroconversion - problems of delivery (obtaining high compliance) was considered a significant drawback of targeted vaccination. Observed relationships between GU clinic attendance and sex partner change rates for heterosexuals and for homosexuals were used to define the rates of vaccination uptake within sexual activity risk groups.

SETTING

England and Wales.

RESULTS

Model results showed that for heterosexuals universal infant vaccination became more effective than clinic based vaccination only approximately 40 years after the start of the programme and that the predicted cost effectiveness of GU clinic vaccination was greater at all times. For homosexuals, clinic vaccination was always more effective over the time frame considered, but by 50 years if it were carried out without prior screening it had become appreciably less cost effective than a mass infant programme. With prior screening in GU clinics this cost effectiveness deficit was only marginal.

CONCLUSIONS

Targeted vaccination might have a much greater potential than is realised at present, particularly if it were possible to improve compliance of clinic attendees. A fuller comparison between mass infant and targeted vaccination must await the specific inclusion in the model of other risk groups such as intravenous drug users. An important determinant of the relative merits of the two approaches is the relationship between rates of attendance and of changing sexual partners. Further research on this is required.

Ante-natal screening for hepatitis B surface antigen: an appraisal of its value in a low prevalence area

The costs and projected benefits of universal screening for hepatitis B virus (HBV) infection in pregnant women in East Anglia are calculated and compared with current practice. By adjusting data from West Midlands region for ethnicity, the prevalence of maternal hepatitis B surface-antigen (HBsAg) positivity in East Anglia is predicted to be 0.083% (1 in 1200). Published data on health risks of perinatal HBV infection and on immunisation efficacy are used to derive benefits of screening. The marginal direct cost of screening is identified from regional sources. Current clinical practice in East Anglia identifies 7 surface-antigen positive mothers per year, whereas 22 are expected. Routine antenatal screening in East Anglia would prevent 2.6 additional childhood carriers per year (compared with current practice), resulting in the prevention of 0.7 deaths per year occurring 40-50 years in the future. The direct cost per (undiscounted) life-year saved would be Pounds 2437, not including savings on treatment for chronic hepatitis B infection. Routine prenatal screening for maternal HBsAg should be introduced without delay and continue even if HBV vaccination is introduced into the UK childhood immunisation schedule.