Response to hepatitis B vaccine in family members of HBsAg carriers

Non-invasive screening of HLA-DPA1 and HLA-DPB1 alleles for persistent hepatitis B virus infection: susceptibility for vertical transmission and toward a personalized approach for vaccination and treatment

BACKGROUND

Polymorphisms in the major histocompatibility complex (MHC) and non-MHC genes were recently reported to be associated with persistent hepatitis B virus (HBV) infection and host response to hepatitis B vaccine in Asian populations. We aimed to confirm the associations in Chinese population and develop a non-invasive screening method for the risk loci.

METHODS

We genotyped 2 risk alleles on the MHC loci, HLA-DPA1 (rs3077) and HLA-DPB1 (rs9277535), and 1 risk allele near a non-MHC gene, FOXP1 (rs6789153) using high-resolution melting curve analysis. With minimal processing steps and time, salivary DNA was extracted with a modified protocol of a blood kit. We compared the genotyping fidelity between peripheral blood DNA and salivary DNA.

RESULTS

Both rs3077 and rs9277535, but not rs6789153, are significantly associated with CHB in Chinese population (p-value<0.001). High genotype concordance between different sources of genomic DNA was obtained.

CONCLUSIONS

Genotyping salivary DNA using our modified methods provides a non-invasive fast screening for host susceptibility loci. The transmission mechanism of hepatitis B can now be modified by adding genetic susceptibility to the traditional vertical transmission model of hepatitis B.

Reduced response to hepatitis B virus vaccination in boys with steroid-sensitive nephrotic syndrome

Vaccination against hepatitis B virus (HBV) was performed in 18 boys (aged 5.7 +/- 2.4 years) suffering from steroid-sensitive nephrotic syndrome (SSNS) and in a control group of 21 healthy boys (aged 5.6 +/- 3.8 years). The percentage of patients who responded to vaccination was significantly lower than the control group 1, 6, 8, 12, 18 and 24 months after the start of vaccination. The titre of antibodies to HBV surface antigen produced by responders at 6 and 24 months was significantly lower in patients than in the control group. Boys with SSNS have an impaired response to HBV vaccination.

Vaccination against hepatitis B and protection against chronic viral carriage in The Gambia

358 children in the Gambian villages of Keneba and Manduar, where hepatitis B virus (HBV) infection is endemic, were vaccinated with plasma-derived vaccine against HBV according to one of four regimens and followed for up to 4 years. Two regimens by which vaccine was injected intradermally into children between 0 and 4 years old led to peak geometric mean (95% CI) concentrations of antibody against HBV surface antigen of 270 (202-358) and 555 (418-748) mlU/ml. The third regimen--intramuscular vaccination of children aged between 0 and 4 years--gave geometric mean peak antibody concentrations of 926 (765-1122) mlU/ml. A fourth regimen was intramuscular vaccination of children between 1 and 9 months old, which gave geometric mean antibody concentrations of 5431 (3903-75,456) mlU/ml. Despite these widely divergent responses and a 89% decay in antibody over the first 2 years, vaccination against HBV was 97% effective in preventing chronic infection. Vaccination was less effective in preventing uncomplicated infection: 5.3% of 264 vaccinees in Keneba and 19.1% of 94 vaccinees in Manduar tested positive for antibody to HBV core antigen. These "breakthrough infections" did not differ in frequency between regimens, and were associated with low initial antibody responses and chronic maternal carriage of HBV.

Hepatitis B vaccination of relatives of hepatitis B virus DNA positive carriers: an experience with plasma-derived vaccine

We assessed in a western population the efficacy of a plasma-derived hepatitis B vaccine in relatives of highly infectious hepatitis B virus (HBV) carriers. A consecutive group of 103 HbsAg, anti-HBs and anti-HBc negative household relatives of 45 HBV-DNA positive chronic carriers received a 5 micrograms dose of plasma-derived vaccine at 0, 1, 2 and 12 months. Protective levels of immunity developed in 101 subjects (97.8%) 3 months after boosting. Low responders to the vaccine were mostly found among parents and spouses of carriers, whilst offspring and siblings were usually high responders. The main discriminant in predicting a good response was age below 12 years. Hyporesponsiveness did not occur in family clusters. No major HBV events occurred among immunized relatives patients. Hepatitis B vaccine is safe and effective in immunizing relatives of HBV carriers while no genetic conditioning of the immune response is evident among them.