Presence Of anti-HBs Antibodies Research Articles

Assessment of anti-HBs antibody concentration in children with juvenile idiopathic arthritis treated with biological drugs, vaccinated against viral type B hepatitis in infancy.

ObjectivesThe introduction of vaccinations against viral hepatitis B in the years 1994–1996 in Poland significantly improved the epidemiological situation of hepatitis B virus (HBV) infections in our country. According to the report of the National Institute of Public Health – National Institute of Hygiene in 2018, 40 cases of acute hepatitis B were noted while still in the 1980s between 10 and 20 thousand new cases were reported annually. The aim of the study was to determine whether in children treated with biological drugs (adalimumab, etanercept, infliximab) due to juvenile idiopathic arthritis (JIA), vaccinated against hepatitis B in infancy, a protective concentration of anti-HBs antibodies persists. In patients, the value ≥ 10 mIU/ml is regarded as a protective concentration of antibodies, determined at least four weeks after administration of the last vaccine dose. Among healthy individuals, presence of anti-HBs antibodies in any concentration means seroprotection. No booster vaccinations are recommended in basically vaccinated healthy individuals.Material and methodsThe concentrations of anti-HBs antibodies were determined in 56 children with JIA (38 girls – 67.9% and 18 boys – 32.1%) aged from 2 years and 4 months to 17.5 years, treated for at least three months with biological drugs. The diagnosis of JIA was made based on the International League of Associations for Rheumatology (ILAR) criteria. All studied patients were at the stable stage of the disease and received a full course of hepatitis B vaccination during infancy (in accordance with 0,1,6 months injection scheme).ResultsIn the studied children a protective anti-HBs antibody concentration was found in 34 cases (60.7%), and 22 children (39.3%) had anti-HBs antibody concentration < 10 mIU/ml (in these children no seroprotection was found).ConclusionsThe post-vaccination antibody concentration should be determined in children with JIA, treated with biological drugs and, in case of absence of a protective concentration, revaccination should be started.

Presence of anti-HBs antibodies in blood donors 18-22 years after vaccination and implications for the selection of candidates for plasmapheresis for the production of hyperimmune plasma.

Hepatitis B virus (HBV) infection is one of the major causes of human morbidity and mortality. It is estimated that at least two billion people are infected worldwide and that more than 350 million are chronic virus carriers; 4.5 million people develop new infections every year, of whom 15–40% will develop cirrhosis, various liver diseases, and hepatocellular carcinomas1. In addition to measures aimed at improving socioeconomic conditions and hygiene standards (the screening of blood units and blood components, the disinfection and sterilisation of medical and surgical instruments, the introduction and use of disposable equipment, and environmental and hospital education campaigns), the implementation of the mass vaccination programmes recommended by the World Health Organization (WHO) since 1992 has dramatically decreased the incidence of HBV infection among children and adolescents2,3. As early as 1983, some Italian regions began selective vaccination of people at risk, including intravenous drug users, male homosexuals, people with multiple sex partners, the life partners of HB surface antigen (HBsAg)-positive patients, haemophiliacs, and newly born babies of HBsAg-positive mothers. In 1991 (with Law N. 165 of 27 May 1991, published in the Official Gazette of the Italian Repreprintlic, 1st June 1991), in addition to maintaining selective vaccination of people at risk, vaccination was made compulsory for all children aged 12 years old (limited to the first 12 years of application) and infants in their first year of life4,5, with the aim of creating immunity in childhood or adolescence in order to protect adults whose lifestyles or occupations may increase the risk of infection. By the end of 2010, more than 20 million children had been vaccinated6 and coverage was 95.3% in 20137. This vaccination campaign therefore created two vaccinated populations: those vaccinated at the age of 12 years and those vaccinated during the first year of life. Numerous studies have been carried out in order to assess and confirm the effectiveness of the vaccination8. Post-vaccination anti-HBs antibody levels of ≥10 mIU/mL are generally considered to be protective8 but, although titres decline over time to undetectable values, this does not indicate a loss of protection and booster vaccine doses are not recommended8–11. Anti-HBs titres and their persistence depend on the number of doses received, the vaccine type, and the route and timing of administration6,8,9,12,13. It has been also observed that lower values are found in subjects vaccinated as infants than in those vaccinated after the first year of life6,9,14. The relative immaturity of the infant immune system could explain the weaker antibody response in subjects vaccinated as infants than in those vaccinated after the first year of life14. However, it is still generally agreed that, regardless of the time of administration, the vaccination induces long-term protection and that there is no need for additional booster doses8,9. On the other hand, antibody levels in young adults may be important in the field of transfusion as it is necessary to identify donors with high anti-HBs titres (after a booster vaccine dose) for the production of anti-HBs hyperimmune plasma15. The aim of this study was to evaluate antibody levels in blood donors 18–22 years after they had been vaccinated during the first year of life or at the age of 12 years.

Highly Sensitive Detection of Hepatitis B Virus Surface Antigen by Use of a Semiautomated Immune Complex Transfer Chemiluminescence Enzyme Immunoassay

The performance of hepatitis B surface antigen (HBsAg) screening assays is continuously improved to reduce the risk of transfusion-associated hepatitis B. In this study, a semiautomated immune complex transfer chemiluminescence enzyme immunoassay (ICT-CLEIA) for the detection of HBsAg, which is as sensitive as hepatitis B virus (HBV) DNA PCR, was developed; the ICT-CLEIA assay performance was compared with the performance of the Architect HBsAg QT assay and HBV DNA PCR. The specificities in the initial assay and after retesting were 99.50% (1,988/1,998 samples) and 99.95% (1,997/1,998 samples), respectively. The analytical detection limit was determined to be 0.2 mIU/ml using the 2nd International WHO HBsAg standard, and the cutoff value (0.5 mIU/ml) of the ICT-CLEIA assay was 8.0 standard deviations (SD) above the mean of the HBsAg-negative specimens. The ICT-CLEIA assay could detect HBsAg even in the presence of anti-HBs antibodies and demonstrated a 23.6-day-shorter window period using commercially available HBsAg seroconversion panels than the Architect HBsAg QT assay. Furthermore, the monitoring of the viral kinetics by the ICT-CLEIA assay and the HBV DNA PCR produced very similarly shaped curves during both the HBsAg seroconversion and reverse seroconversion periods. Therefore, the ICT-CLEIA assay may be useful not only for an earlier detection of HBV reactivation but also for the monitoring of hepatitis B patients.

Occult HBV infection among anti-HBc positive HIV-infected patients in apex referral centre, Eastern India

Background. The prevalence of occult HBV, defined by the presence of HBV DNA in individuals with antibodies to HBV core antigen and with absence of HBV surface antigen, but its clinical significance and virological features in HIV-infected patients is still unclear.Aim. To investigate the prevalence, clinical significance and molecular characterization of occult hepatitis B virus infection in ART-Naive HIV-positive individuals.Material and methods. Among the 1077 HIV-infected patients with different risk factors for HIV infection, 297 were HBsAg-ve ART-naive, of them 112 was randomly selected for the study. HBV DNA was tested by in-house PCR and quantified by qPCR. Molecular characterization was performed by sequencing the envelope and overlapping polymerase genes.Results. We found the prevalence of occult HBV to be 10.7% among a randomly selected group of HBsAg-ve/antiHBc+ve HIV-infected patients. Overall 33.9% (38 of 112) of the patients were antiHBc positive indicating exposure to HBV infection. HBV DNA was detected in 12/38 (31.5%) antiHBc positive samples and 50% of them had CD4 T cell count < 200 cells/mm3. HCV coinfection was low (2.7%). No surrogate marker for OBI could be identified. Presence of antiHBs antibodies did not rule out OBI. Liver biopsy in six cases showed varying stages of chronic hepatitis. Several mutations were detected but not the common immune escape mutant G145R.Conclusion. In conclusion the prevalence of OBI was significantly high among HIV coinfected patients, which highlights the importance of HBV DNA testing in these patients and indicates need for further prospective studies in larger cohorts to assess its clinical significance.

Occult Hepatitis B Virus infection in ART-Naive HIV-Infected Patients seen at a Tertiary Care Centre in North India

BackgroundCo-infections of hepatitis B and C viruses are frequent with HIV due to shared routes of transmission. In most of the tertiary care health settings, HIV reactive patients are routinely tested for HBsAg and anti-HCV antibodies to rule out these co-infections. However, using the routine serological markers one can only detect active HBV infection while the occult HBV infection may be missed. There is insufficient data from India on HIV-HBV co-infection and even scarce on occult HBV infection in this group.MethodsWe estimated the burden of HBV infection in patients who were tested positive for HIV at a tertiary care centre in north India. We also attempted to determine the prevalence and clinical characteristics of occult HBV infection among these treatment-naïve patients and compare their demographic features with other HIV patients. During a period of 6 years between January 2002 to December 2007, 837 HIV positive patients (631 males and 206 females (M: F :: 3.06:1) were tested for serological markers of HBV (HBsAg) and HCV (anti-HCV antibodies) infections in our laboratory. For comparison 1000 apparently healthy, HIV-negative organ donors were also included in the study. Data on demographics, sexual behaviour, medical history, laboratory tests including the serum ALT and CD4 count of these patients were recorded. A sub-group of 53 HBsAg negative samples from HIV positive patients were assessed for anti-HBs, anti-HBc total (IgG+IgM) and HBV-DNA using a highly sensitive qualitative PCR and analysed retrospectively.ResultsOverall, 7.28% of HIV positive patients showed presence of HBsAg as compared to 1.4% in the HIV negative control group. The prevalence of HBsAg was higher (8.55%) in males than females (3.39%). The study revealed that occult HBV infection with detectable HBV-DNA was prevalent in 24.5% of patients positive for anti-HBc antibodies; being 45.5% in HBsAg negative patients. Most importantly the occult infection was seen in 20.7% patients who were positive for anti-HBs antibodies. However, in none of the seronegative patient HBV-DNA was detected. Five of the nine HBV-DNA positive (55.6%) patients showed raised alanine aminotransferase levels and 66.7% had CD4+ T cell counts below 200 cells/cumm.ConclusionsHigh prevalence of HIV-HBV co-infection was found in our patients. A sizeable number of co-infected patients remain undiagnosed, if only conventional serological markers are used. Presence of anti-HBs antibodies was not a reliable surrogate marker to rule out occult HBV infection. The most reliable method to diagnose occult HBV co-infection in HIV seropositive patients is the detection of HBV-DNA.

Successful interferon treatment in a patient chronically infected with hepatitis B virus carrying unusual S‐ (and P‐) mutants in the presence of anti‐HBs antibodies

Hepatitis B virus (HBV) immune escape mutants with point mutations within the S gene may arise during the natural course of HBV infection, due to a positive selection pressure exerted by the host immune response. Mutations within the immunodominant B and T cell epitopes of hepatitis B surface antigen (HBsAg) allow the resulting S-mutants to propagate even in the presence of neutralizing anti-HBs antibodies and the HBV-specific T-cell immune response. To study the antiviral effect of Pegylated-interferon (Peg-IFN) in a patient with chronic hepatitis B carrying unusual S-(and P-) mutants in the presence of anti-HBs antibodies. We report on a 43-year-old male chronically infected with a genotype A HBV strain, with cocirculation of both HBsAg and anti-HBs antibodies, who received treatment with 120 mug of Peg-IFN for 24 weeks. HBeAg seroconversion and clearance of both HBV DNA by polymerase chain reaction and HBsAg were successfully achieved. Improved histology was observed in a biopsy performed 44 weeks after Peg-IFN therapy was completed. It seems plausible that the ascribed genotype A could have contributed to the effective response to Peg-IFN, even though the treatment was provided only throughout a 24-week period. To our knowledge, this is the first report regarding the successful result obtained by using Peg-IFN as a treatment for a chronically HBV-infected patient carrying HBsAg immune escape mutants.

Dynamics of a hepatitis B virus e antigen minus population ascribed to genotype F during the course of a chronic infection despite the presence of anti-HBs antibodies

The in vivo evolution of genotype F HBV variants was recorded in a chronically infected patient throughout a 3-year observation period. Fluctuating levels of HBs Ag and anti-HBs antibodies were recorded, both of them cocirculating in peripheral blood samples at given times. Fifty S gene derived clones were sequenced and phylogenetically analyzed. As expected, some amino acid replacements within the S ORF were also observed within the P ORF while others were silent for the former. Such change was statistically significant for both S and P overlapping genes, which clearly indicates the appearance of a positive selection pressure. Supporting this notion, amino acid replacements were documented at both B and T cell epitopes in samples from 1997 and 1998. Several mutations were documented within and outside the “ a” determinant in the major hydrophilic region. Such substitutions might have resulted from the attempt of HBV to evade both humoral and/or cellular immune response. To the best of our knowledge this unusual profile of HBV variants in presence of usually “neutralizing” anti-HBs antibodies was examined in vivo for the first time.