Search

BACKGROUND Occult hepatitis B infection (OBI) has been described in various clinical settings including after hepatitis B virus (HBV) immunization. The purpose of study was to characterize the prevalence of OBI among immunized children from a subset of general population and the parents of OBI-positive cases. METHODS Sera of 1200 children from general population who have been previously immunized by HBV vaccine were assayed for anti-HBs. 660 were randomly selected for HBV DNA testing by different polymerase chain reaction (PCR) methods and were analysed by direct sequencing on surface genes. RESULTS None of participants were positive for HBsAg and anti-HBc. 549 (45.7%) and 651 (54.3%) cases had anti-HBs > 10 mIU/mL (responders) and

BackgroundMost Chinese Blood Centers adopted mini pool (MP) nucleic acid testing (NAT) for HBV screening due to high cost of Individual donation (ID) NAT, and different proportions of MP-reactive but ID-non-reactive donations (MP+/ID−, defined as non-resolved donations) have been observed during daily donor screening process. Some of these non-resolved donations are occult HBV infections (OBIs), which pose potential risk of HBV transmission if they are not deferred. This study is aimed to further analyze these non-resolved donations.MethodsThe non-resolved plasma samples were further analyzed by serological tests and various HBV DNA amplification assays including quantitative PCR (qPCR) and nested PCR amplifying the basic core and pre-core promoter regions (BCP/PC; 295 base pairs) and HBsAg (S) region (496 base pairs). Molecular characterizations of HBV DNA+ non-resolved samples were determined by sequencing analysis.ResultsOf 17,226 MPs from 103,356 seronegative blood donations, 98 MPs were detected reactive for HBV. Fifty-six out of these 98 (57.1%) reactive MPs were resolved as HBV DNA+, but the remaining 42 pools (42.9%, 252 donations) were left non-resolved with a high rate (53.2%) of anti-HBc+. Surprisingly, among 42 non-resolved MPs, 17 contained one donation identified as OBIs by alternative NAT assays. Sequence analysis on HBV DNAs extracted from these OBI donations showed some key mutations in the S region that may lead to failure in HBsAg detection and vaccine escape.ConclusionA total of 53.2% of the non-resolved donations were anti-HBc+, and OBIs were identified in 40.5% of these non-resolved pools. Therefore, non-resolved donations with anti-HBc+ might pose potential risk for HBV transmission. Our present analysis indicates that anti-HBc testing in non-resolved donations should be used to identify OBIs in order to further increase blood safety in China.

Occult hepatitis B infection is characterized by negative hepatitis B surface antigen (HBs Ag) and also detectable hepatitis B virus (HBV) DNA. Spontaneous HBs Ag-negative is a rare occurrence in chronic hepatitis B patients. This study aimed to determine the prevalence of HBV DNA in patients that surface antigen hepatitis B virus had lost. During this study, 3320 patients with chronic hepatitis B were followed, of which 1750 patients were men and 1570 patients women. They were HBs Ag-negative patients and AST and ALT levels were normal in them. To isolate HBV DNA, real-time PCR technique was performed, while ELISA technique was used to detect HBs Ag. Data collected and analyzed by SPSS software. Of the 3320 patients with chronic hepatitis B virus, 96 patients—including 62 men (64.5%) and 34 women (35.4%)—had no HBV surface antigen and a significant relationship was observed between HBs Ag clearance process and gender (p value = 0.05). The prevalence of HBV DNA was reported in 29.2% of cases. It is worth noting that between HBV DNA positive and using antiviral drugs, a significant relationship has been observed in patients (p = 0.0001). Our results showed a significant relationship between existence of HBV DNA and drug consumption.

INTRODUCTION: Occult hepatitis B infection (OBI) may contribute to liver damage and variable therapeutic response in patients with chronic hepatitis C (CHC) infection. AIMS: To study the prevalence of OBI and to evaluate its impact and/or that of anti-HBc total seropositivity on clinical outcomes and response to directly acting antiviral (DAA) therapy in CHC-infected patients. SETTINGS AND DESIGN: A retrospective cohort study was conducted in a tertiary care liver hospital from January to May 2017. SUBJECTS AND METHODS: Eighty HBsAg-negative CHC patients who were initiated on DAA therapy were retrospectively included. Archived pretreatment baseline plasma samples were retrieved and tested for quantitative HBV DNA, anti-HBs, and anti-HBc total antibodies. HCV RNA, genotype, clinical, biochemical and histopathological parameters & treatment response data were obtained from the hospital information system. STATISTICAL ANALYSIS USED: Comparison of continuous variables was done by Mann–Whitney and Kruskal–Wallis tests and categorical variables by Fisher’s exact test or Pearson’s Chi-square test. RESULTS: Prevalence of OBI was 1.25%. Anti-HBc total positivity was seen in 25% patients. Based on anti-HBc total status, patients were categorized into two groups namely Group 1 (anti-HBc positive) and Group 2 (anti-HBc negative). Group 1 patients were further categorized into three subgroups based on signal/cutoff (S/Co) of HBc total antibody semi-quantitative values. HBc total antibody levels did not influence the severity of CHC disease. Comparative evaluation of parameters such as median log10 baseline RNA (P = 0.929 and 0.464), median alanine aminotransferase (ALT 0) (P = 0.519 and 0.449), ALT at 12 weeks (P = 0.875 and 0.594), sustained virological response (SVR) at 12 weeks (P = 0.405 and 0.263) and SVR at 24 weeks (P = 0.265 and 0.625) between Groups 1 and 2 and among three categories within Group 1, respectively, were not found to be statistically significant. Conclusions: Very low prevalence of OBI was seen in CHC patients. HBc total antibody levels did not influence clinical outcome and response to DAA therapy in this cohort.

We tested the frequency of occult hepatitis B infection (OBI) among Egyptian healthcare workers (HCWs). We tested 132 HCWs for hepatitis B virus (HBV) DNA by nested polymerase chain reaction (PCR), and hepatitis C virus antibody (anti-HCV) by ELISA. HCV RNA was measured by nested PCR in anti-HCV-positive HCWs. HBV-DNA-positive HCWs were subjected to HBV genotyping. We included 132 HCWs who were negative for hepatitis B surface antigen and positive for hepatitis B core antibody (anti-HBc). OBI was detected in 7 male HCWs, and HBV E genotype was detected in 3, HBV D in 2 and HBV D and E in 2. Two OBI-positive HCWs had a history of neonatal hepatitis B vaccination. Anti-HCV seropositivity was detected in 17 HCWs who were positive for anti-HBc; 15 of whom were positive for HCV RNA by nested PCR. HCV infection was confirmed by anti-HCV and HCV RNA in 1 of 7 HCWs with OBI. In conclusion, Egyptian HCWs have a significant rate of OBI and HBV E genotype is prevalent.الإصابة بعدوى التهاب الكبد الوبائي B الخفي بين العاملين في مجال الرعاية الصحية في مصر.ريم المغلوب، أشرف البحراوي، جمال الديداموني، علاء هاشم، محمد حنفي مرسي، أسامة حنطور، عبد اللطيف حنطور، محمد عبد البصير.أجرينا اختباراً لمدى تكرار الإصابة بعدوى فروس التهاب الكبد B الخفي (OBI) ما بن العاملن المصرين في مجال الرعاية الصحية. وأجرينا تحلياً ل 132 عاماً في المجال الصحي للكشف عن ال DNA لفيروس التهاب الكبد B باستخدام ال PCR المزدوج، والكشف عن الأجسام المضادة لفروس التهاب الكبد C باستخدام ال ELISA. وقيس ال (RNA) لفيروس التهاب الكبد C باستخدام ال PCR المزدوج. وتم الكشف عن الإصابة بفروس التهاب الكبد B الخفي في 7 عاملن ذكور من العاملن في مجال الرعاية الصحية، والنوع الجيني E لفيروس التهاب الكبد B في 3 عاملن، والنوع الجيني D في عاملنْ اثنن، والنوع الجيني E و D في عاملنْ اثنن. وتبنّ أن اثنن من العاملن الذين ثبت إصابتهم بفروس التهاب الكبد B الخفي سبق لهم التطعيم ضد التهاب الكبد B المقدّم لحديثي الولادة. وتم الكشف عن إيجابية مصلية للأجسام المضادة لفروس التهاب الكبد C في 17 عاماً من العاملن في المجال الصحي الذين جاءت نتائج تحليلهم إيجابية للأجسام المضادة لفروس التهاب الكبد B ؛ 15 منهم جاءت نتائجهم إيجابية لل RNA لفروس التهاب الكبد C باستخدام ال PCR المزدوج. نخلص من ذلك إلى ارتفاع معدل الإصابة بفروس التهاب الكبد B الخفي بن العاملن في مجال الرعاية الصحية في مر مع انتشار النوع الجيني E من فروس التهاب الكبد B.Hépatite B occulte chez des agents de soins de santé égyptiens.Nous avons étudié la fréquence de l’hépatite B occulte chez des agents de soins de santé égyptiens. Nous avons examiné 132 agents de santé à la recherche d’ADN du virus de l’hépatite B (VHB) au moyen de l’amplification en chaîne par polymérase (PCR) nichée et de l’anticorps du virus de l’hépatite C (anti-VHC) par la méthode ELISA. L’ARN du VHC a été mesurée par PCR nichée chez des agents de santé positifs pour l’anticorps anti-VHC. Les agents de santé positifs pour l’ADN du VHB ont été soumis au génotypage du VHB. Nous avons inclus 132 agents de soins qui étaient négatifs pour l’antigène de surface de l’hépatite B et positifs pour l’anticorps antinucléaire de l’hépatite B (Anti-HBc). Une hépatite B occulte a été détectée chez 7 agents de santé de sexe masculin, et le VHB de génotype E a été détecté chez trois agents, le VHB de génotype D chez 2 agents, et le VHB de génotype D et E chez 2 agents. Deux des agents positifs pour l’hépatite B occulte avaient été vaccinés durant la période néonatale. Une séropositivité anti-VHC a été détectée chez 17 agents de santé qui étaient positifs pour l’anticorps anti-HBc, dont 15 étaient positifs pour l’ARN du VHC par PCR nichée. L’infection à VHC a été confirmée par l’anti-VHC et par l’ARN du VHC chez 1 agent sur 7 atteints d’hépatite B occulte. En conclusion, les agents de santé égyptiens ont un taux d’hépatite B occulte significatif et le génotype E du VHB est prévalent.

INTRODUCTION: HBV and HIV have identical transmission routes. The aim of this study was to determine the prevalence of HBV in HIV patients and to detect the presence of occult HBV infection. METHODS: All samples were tested for serology markers and using qPCR. RESULTS: This study included 232 individuals, out of which 36.6% presented with HBV markers and 11.8% presented with HBsAg or HBV-DNA, including 3 patients that showed OBI. CONCLUSIONS: We observed a high prevalence of HBV among HIV patients. In addition, the results suggest that OBI can occur in patients with serological profiles that are indicative of past infection. Therefore, the application of molecular tests may enable the identification of infections that are not evident solely based on serology.

International audience; BackgroundIn Cameroon, the prevention of hepatitis B virus (HBV) transmission by blood transfusion is still only based on hepatitis B surface antigen (HBsAg) screening. However, occult HBV infection (OBI) characterised by the absence of detectable HBsAg and low level of viral DNA remains a potential threat for blood safety. The prevalence of OBI was investigated in blood donors from Yaoundé to provide evidence-based recommendations to improve HBV blood safety.Material and methodsBlood donations from August 1st, 2016 to March 31st, 2017 were routinely screened for HBV, human immunodeficiency virus (HIV), and hepatitis C virus (HCV) infections (Murex HBsAg Version 3, Murex HIV Ag/Ab Combination, and Murex HCV Ag/Ab Combination [DiaSorin]). Additional HBV investigations were performed, including hepatitis B core antibody ([HBc] Monolisa Anti-HBc PLUS; BIO-RAD) and HBV DNA tested in minipools of two samples using the quantitative Cobas Taqman HBV assay (Roche; LoQ: 6 IU/mL) and HBV DNA genotyping by sequencing.ResultsOf 1,162 donations analysed, 91 (7.8%) were reactive for HBsAg. All of them were also anti-HBc positive. Among the 1,071 HBsAg negative samples, 522 (48.7%) were reactive for anti-HBc. Six (0.56% of all donations) samples fulfilled the consensus definition of OBI and showed low HBV DNA loads (all

Background Transfusion-transmitted hepatitis B virus continues to be a problem despite its significantly reduced prevalence. In this study, in addition to screening for the presence of HBsAg in donors' blood, anti-HBc and anti-HBs markers were investigated using the chemiluminescence immunoassay (CLIA) method, and real-time PCR was used to detect HBV DNA. Methods The study's material involved serum samples of 4,073 blood donors. HBsAg, anti-HBs, anti-HBc tests were undertaken using the CLIA method, and HBV DNA's presence was investigated using the real-time PCR method. Results HBsAg and anti-HBc tests were negative in 3,331 (81.78%) and positive in 37 (0.90%). For the remaining 705 (17.30%), HBsAg was negative and anti-HBc was positive. According to the results of the anti-HBs test for these samples, HBsAg negativity and anti-HBc and anti-HBs positivity were found in 619 samples (15.19%), while 86 samples (2.11%) were negative for HBsAg and anti-HBs but positive for anti-HBc (isolated anti-HBc positivity). ID-HBV DNA real-time PCR tests were performed on 86 samples. None of the samples was positive for HBV DNA. Conclusions Recommended tests for screening occult HBV infection include anti-HBc, anti-HBs, and/or HBV DNA. Anti-HBc screening may result in loss of donors and blood products, particularly in countries with moderate endemicity of HBV, such as Turkey.

Background and Aims: Occult hepatitis B virus infection (OBI) is known as an important source of hepatitis B virus (HBV) infection. It is categorized as Hepatitis B surface antigen (HBsAg) not being present and low DNA viral load in serum. In this study, an attempt was made to investigate the outbreak of anti-HBc and OBI among the HBsAg-negative donors in Golestan province. Materials and Methods: The present cross-sectional experiment was conducted on 3500 voluntary blood donors in Golestan province to examine the presence of human immunodeficiency viruses Ag-Ab, HBsAg, and hepatitis C virus Ab. Then, samples with negative results for the mentioned tests were screened for total HBc antibody (IgM-IgG) through ELISA technique. Afterward, HBV-DNA extraction and R-T PCR assay were conducted for all HBsAg negative samples by using Real ART HBV LC PCR kit on a Light Cycler instrument. Results: The study participants included 3255 (93%) male and 245 (7%) female. In general, 385 (11%) out of 3500 samples were anti-HBc positive. HBV-DNA results for every sample with either positive or negative anti-HBc were found to be negative. Conclusions: As the area under study has a high rate of anti-HBc outbreak (11%) without the presence of HBV-DNA, anti-HBc screening can cause blood donor deferrals and limit blood supply; therefore, the HBsAg test with high analytical sensitivity is recommended for HBV screening in this area. Regarding the cost analyses and also the status of HBV endemicity, HBsAg test along with ID-NAT is preferable, if possible, for improving blood safety.

Aim: The aims of this study were to find out the prevalence of occult hepatitis B infection (OBI) in HIV-1 patients, as well as to analyze the mutational patterns of OBI-positive individuals. Materials & methods: 172 HBsAg-negative, HIV-1-positive patients were selected according to data extracted from questionnaires. HBV serologic and molecular assays were performed. An extensive mutational analysis was applied using direct sequencing on HBsAg. Results: Thirty-one samples (18%) were OBI positive. Among 24 available OBI-positive samples, 17 (71%) contained at least one mutation only within ‘a’ determinant region of HBsAg. A stretch of mutations was found between amino acid positions 121 and 136. The physicochemical properties of individual amino acid substitutions and their potential impacts on 3D structure of ‘a’ determinant mutants were also determined. Conclusion: HBV serologic assays are not reliable markers to exclude occult HBV infection in HIV-positive patients.

Occult hepatitis B infection (OBI) is the presence of hepatitis B virus (HBV) DNA in the liver and/or serum (< 200 IU/mL) in HBsAg-negative patients with or without serologic markers of previous viral exposure. The clinical significance of OBI is of concern in post-transfusional hepatitis B infection, hepatitis B reactivation, chronic liver disease and hepatocellular carcinoma (HCC). The diagnosis of OBI relays on the use of highly sensitive and specific laboratory techniques. Herein, comments derived from a study analyzing the frequency and characteristics of OBI in HCC Japanese patients are stated. While OBI and other causes of HCC have been highly studied in Asia and Europe, research in Latin America in these topics is limited. Several findings such as population risk groups with high prevalence of overt and OBI infection, HBV genotype F in Argentinean HCC patients, and the clinical impact of the foreign A-D genotypes suggest the need of further investigation. Additionally, alcoholism, obesity, NASH and type 2 diabetes may override the presence of OBI. Therefore, OBI diagnosis is essential. It is known that anti-HBc alone is a predictive signal of potential OBI and given the fluctuations of the HBV infection markers, testing for HBsAg and anti-HBc at baseline and follow-up is recommended. In conclusion, OBI and other causes involved in the epidemiology of HCC in Latin America are unexplored risk factors. Genome-based research is required to decipher the role of gene-environmental interactions associated with chronic liver disease. Novel algorithms to detect OBI supported by basic/applied/clinical research are also needed.

Objectives: Health care workers, including dentists, are at the front line for acquiring blood-borne virus infections. This study aimed to investigate the prevalence of hepatitis B, hepatitis C and human immunodeficiency viruses among Iranian dentists. Material and Methods: The survey included 1628 dental health care workers who attended the 51st annual Congress of the Iranian Dental Association. Data on the risk of blood-borne virus transmission during health care and infection control practices were gathered from self-administered questionnaires. Sera were screened serologically by enzyme-linked immunosorbent assay (ELISA). The positive samples were examined by polymerase chain reaction (PRC) followed by direct sequencing. Results: Six (0.36%) and 81 (5.0%) were positive for hepatitis B surface antigen (HBsAg) and (anti-hepatitis B virus core antigen (anti-HBc), respectively. Only 1 (0.061%) was positive for anti-hepatitis C virus (anti-HCV). No case was positive for anti-human immunodeficiency virus (anti-HIV). One case was diagnosed as being occult hepatitis B virus (HBV) infection. One thousand five hundred thirty-five (94.3%) of participants had received at least 1 dose of HBV vaccine. One thousand three hundred fifty-nine (88.5%) contained hepatitis B surface antibody (anti-HBs) > 10 IU/ml, of whom 55 (4.0%) were anti-HBc positive, suggesting that they had been infected with HBV in the past. Anti-HBc positive cases had past histories of hepatitis, either their own or their spouses’. Individuals with inadequate anti-HBs levels (< 10 IU/ml) were significantly more prevalent among anti-HBc positive cases (p < 0.001). Conclusions: The prevalence of blood-borne viruses among dental HCWs found in this study was lower than past reports from Iranian dentists and general population. The implementation of HBV vaccination together with improvement in infection control procedures has reduced the potential for risk infection among Iranian dentists.

BACKGROUND Many studies have identified mutations in the hepatitis B surface antigen (HBsAg) as important factors limiting the ability of commercial serological assays to detect this viral antigen. However, an association between mutations in the HBsAg gene and the occurrence of occult HBV infection (OBI) in patients has not been established. OBJECTIVES To detect hepatitis B virus (HBV) DNA in patients with anti-HBc as a unique serological marker, a previously published, cost-effective TaqMan-based real-time polymerase chain reaction (PCR) test with minor groove binding probes was adapted for use in this study. The current study also aimed to investigate HBsAg mutations and genotypes of HBV in OBI at the Viral Hepatitis Ambulatory Clinic in Rio de Janeiro to determine any possible association. METHODS Intra-assay and inter-assay reproducibility were determined, and the mean coefficient of variation values obtained were 2.07 and 3.5, respectively. Probit analysis indicated that the 95% detection level was 25 IU/mL. The prevalence of OBI was investigated in 35 serum samples with an ‘anti-HBc alone’ profile from individuals who attended our clinic between 2011 and 2013. FINDINGS HBV DNA was detected in only one sample, resulting in an OBI rate of 2.9%. Nucleotide sequencing of the pre-S/S region was performed to genotype and analyse mutations within the HBsAg gene of this HBV DNA. The HBV in the OBI case was classified as sub-genotype A1, and a sequence analysis of the small S gene revealed 12 mutations in the major hydrophilic region compared to the consensus A1 sequence. Most of these mutations occurred in amino acid residues that have been reported as clinically relevant because they have been implicated in vaccine escape and/or inability to detect HBsAg by commercial serological assays. MAIN CONCLUSIONS Our study suggests the importance of specific HBsAg mutations, different from those in D, B, and C genotypes, in sub-genotype A1 HBV associated with OBI.

Studies on the prevalence of infection with hepatitis B virus (HBV) among children are scarce in Latin American countries, especially in Mexico. This study was aimed to investigate the prevalence of HBV infection, occult hepatitis B infection (OBI) and HBV genotypes among children with clinical hepatitis. In total, 215 children with clinical hepatitis were evaluated for HBV infection. HBV serological markers and HBV DNA were analysed. OBI diagnosis and HBV genotyping was performed. HBV infection was found in 11.2% of children with clinical hepatitis. Among these HBV DNA positive-infected children, OBI was identified in 87.5% (n = 21/24) of the cases and 12.5% (n = 3/24) were positive for both HBV DNA and hepatitis B surface antigen. OBI was more frequent among children who had not been vaccinated against hepatitis B (p < 0.05) than in those who had been vaccinated. HBV genotype H was prevalent in 71% of the children followed by genotype G (8%) and genotype A (4%). In conclusion, OBI is common among Mexican children with clinical hepatitis and is associated with HBV genotype H. The results show the importance of the molecular diagnosis of HBV infection in Mexican paediatric patients with clinical hepatitis and emphasise the necessity of reinforcing hepatitis B vaccination in children.

Purpose Occult hepatitis B infection (OBI) among HIV positive patients varies widely in different geographic regions. We undertook a study to determine the prevalence of occult hepatitis B infection among HIV infected individuals visiting a health facility in South West Cameroon and characterized occult HBV strains based on sequence analyses. Methods Plasma samples (n = 337), which previously tested negative for hepatitis B surface antigen (HBsAg), were screened for antibodies against hepatitis B core (anti-HBc) and surface (anti-HBs) antigens followed by DNA extraction. A 366 bp region covering the overlapping surface/polymerase gene of HBV was then amplified in a nested PCR and the amplicons sequenced using Sanger sequencing. The resulting sequences were then analyzed for genotypes and for escape and drug resistance mutations. Results Twenty samples were HBV DNA positive and were classified as OBI giving a prevalence of 5.9%. Out of these, 9 (45%) were anti-HBs positive, while 10 (52.6%) were anti-HBc positive. Additionally, 2 had dual anti-HBs and anti-HBc reactivity, while 6 had no detectable HBV antibodies. Out of the ten samples that were successfully sequenced, nine were classified as genotype E and one as genotype A. Three sequences possessed mutations associated with lamivudine resistance. We detected a number of mutations within the major hydrophilic region of the surface gene where most immune escape mutations occur. Conclusions Findings from this study show the presence of hepatitis B in patients without any of the HBV serological markers. Further prospective studies are required to determine the risk factors and markers of OBI. Electronic supplementary material The online version of this article (doi:10.1186/s12981-017-0136-0) contains supplementary material, which is available to authorized users.

This article is part of Viet Le's doctoral thesis which is available in Munin at http://hdl.handle.net/10037/6970 Safe blood and blood products should be offered to all patients in need for blood transfusion. The objectives of the present study were to establish prevalence estimates for hepatitis B and hepatitis C virus infections as a foundation for safe blood transfusion in rural Vietnam, and to check the accuracy of the laboratory analysis used for hepatitis testing of blood donors in Vietnam. A cross-sectional study was conducted in two rural communities in Quang Tri, Vietnam. A total of 1,200 blood samples collected from potential blood donors were tested by an enzyme immunoassay technique (EIA) for detection of hepatitis surface antigen (HBsAg), antibodies to hepatitis B core antigen (anti-HBc), and antibodies to hepatitis C antigen (anti-HCV). The EIA test outcome was validated by a chemiluminescent micro particle immunoassay technique (CMIA). Results: The prevalence of HBsAg and anti-HBc in the study population was 11.4 per cent (95% CI 9.6 - 13.2) and 51.7 per cent (95% CI 48.8 - 54.5), respectively, the prevalences being higher in males than females. The prevalence of anti-HCV was 0.17 per cent. The test agreement between the EIA and CMIA techniques was high both for HBsAg detection (κ = 0.91; 95% CI: 0.83 - 0.99) and for anti-HBc detection (κ = 0.89; 95% CI 0.81 - 0.97). Compared to CMIA results, the positive and negative predictive values of the EIA tests were found to be 94.9 per cent (95% CI 87.5 - 98.6) and 97.5 per cent (95% CI 86.8 - 99.9) for HBsAg, and 92.4 per cent (95% CI 84.2 - 97.2) and 100 per cent (95% CI 91.2 - 100) for anti-HBc. Interpretation & conclusions: The study shows that hepatitis B virus infection is endemic in rural areas of Vietnam and that almost half of the population is or has been infected. Hepatitis C infection is rare, but false negative test results cannot be ruled out. Also, the results indicate that the EIA performance in blood donor screening in Vietnam may be sub-optimal, missing 2.5 per cent of hepatitis B virus carriers and falsely excluding more than 7 per cent of blood donors. As the prevalence of hepatitis B infection is high, occult hepatitis B infection may represent a threat to safe blood transfusion. Therefore, nucleic acid amplification testing for HBV should be considered for blood donor screening in Vietnam.

Background/Aim: Occult hepatitis B infection (OBI) is identified as a form of hepatitis in which despite the absence of detectable HBsAg, HBV-DNA is observed in peripheral blood of patients. The main aim of this study has been to investigate the association between polymorphisms in +874 of IFN-γ and +1188 of IL-12 with their serum level in patients suffering from OBI. Materials and Methods: In this experimental study, plasma samples of 3700 blood donors were tested for the presence of hepatitis B surface antigen (HBsAg) and anti-HBc by ELISA. The HBsAg - /anti-HBc + samples were selected and screened for HBV-DNA by PCR. HBV-DNA positive samples were assigned as OBI cases and ARMS-PCR techniques were performed to examine the two known polymorphisms within IL-12 and IFN-γ. In addition, the serum levels of IL-12 and IFN-γ were also determined by ELISA. Results: Results of this study demonstrated that, 352 (9.5%) out of 3700 blood samples were HBsAg - /anti-HBc + and HBV-DNA was detected in 57/352 (16.1%) of HBsAg - /anti-HBc + samples. Our results showed that groups showed significant difference in CC allele of +1188 region of IL-12 and no difference was observed in the other evaluated genes. Our results also showed that the alleles of +1188 region of IL-12 and alleles of +874 of IFN-γ were also not associated with serum level of cytokines. Conclusion: According to the results of this study, it may be concluded that the polymorphisms in +1188 region of IL-12 and +874 region of IFN-γ would not affect the expression of both cytokines at serum level in OBI patients.

Background and Objective: Occult hepatitis B infection is a form of hepatitis in which despite of absence of detectable HBsAg, HBV-DNA is present in peripheral blood of patients. The mechanisms which are responsible for progression of OBI yet to be clarified but some investigators believed that the genetics and immunological parameters may are different in resistant individuals and patients. Cytokine network system could be leading alteration in viral immune response. The aim of this study was to investigate the relation between polymorphisms +874 region of IFN-Gama with occult hepatitis B infection. Materials and Methods: In this study, the plasma samples of 3700 blood donors were tested for HBsAg and anti-HBs by ELISA. The HBsAg negative and anti-HBc positive samples were selected and screened for HBV-DNA by PCR. HBV-DNA positive samples assigned as occult hepatitis B infection cases and ARMS-PCR technique were performed to examine the present polymorphisms in +874 region of IFN-Gama genes of patients with occult hepatitis B infection. Results: 352 (9.51%) out of 3700 blood samples were negative for HBsAg and positive for anti-HBc antibody. HBV-DNA was detected in 57 (16.1%) of HBsAg negative and anti-HBc positive samples. Our results showed that there was not any significant difference between patients and control group in polymorphisms in +874 region of IFN-Gama genes. Conclusion: This study showed that there is not any significant difference between polymorphisms in +874 region with IFN-Gama occult hepatitis B infection.

Background and Aims Occult hepatitis B infected (OBI) patients can not completely eradicate hepatitis B virus-DNA (HBV-DNA) from their liver and peripheral blood. The main aim of this study was to investigate the Interleukin (IL)-10and IL-17A serum levels in patients suffering from OBI. Material and Methods In this observational study, plasma samples of 3700 blood donors were tested for hepatitis Bsurface antigen (HBsAg) and antibodies to the hepatitis B core antigen (anti-HBc), using enzyme-linked immunosorbent assay (ELISA). The HBsAg-/anti-HBc+ samples were selected and screened for HBV-DNA, using the polymerase chain reaction (PCR). HBV-DNA positive samples were assigned as OBI cases and IL-10 and IL-17 serum levels were detected using ELISA. Results The results demonstrated that, 352 (9.5%) out of 3700 blood samples were HBsAg-/anti-HBc+ and HBV-DNA was detected in 57/352 (16.1%) of the HBsAg-/anti-HBc+ samples. Our results showed that the IL-10 and IL-17A serum levels increased significantly in the OBI cases in comparison to the controls (P < 0.001). Conclusions According to the results of this study the higher level of IL-10 production may suppress the functioning of the immune system against HBV in OBI patients. The elevated IL-17A serum level also indicates a long period of infection in the patients observed.

Background: Occult hepatitis B infection (OBI) is a form of viral hepatitis in which the HBV-DNA is present in blood while the HBsAg is undetectable. As differences in genetics and immunological responses have important role on OBI we were persuaded to analyze the known CCR5-D32 mutation (a chemokine receptor) in patients with OBI.Materials and Methods: In this descriptive study, 3700 blood samples that were HBsAg negative were collected during March 2006 to February 2007, from Rafsanjan blood transfusion services. All samples were tested for anti-HBc antibody. The HBsAg negative and anti-HBc positive samples were analyzed for HBV-DNA by PCR technique. The HBV-DNA positive samples were regarded as OBI cases. Finally, the Gap-PCR was performed to examine the d32 mutation in OBI patients. Results: The analysis of results showed that 352 (9.51%) cases of HBsAg negative samples were positive for anti-HBc. Following examination of HBsAg negative and anti-HBc positive samples for HBV-DNA by PCR based methods; we found that 57(16.1%) cases had HBV-DNA. None of the OBI patients had d32 mutation in CCR5 chemokine receptor whereas 2(2%) of controls had heterozigotic form of this mutation.Conclusion: Based on the results of this study it seems that CCR5-D32 mutation does not affect the immune response against HBV to make OBI.

(Received 5 Oct, 2008; Accepted 14 Feb, 2009)AbstractBackground and purpose: Occult hepatitis B infection (OBI) is defined as a form of hepatitis B that despite absence of detectable HBsAg, HBV-DNA is present in patient’s peripheral blood. Genetic and immunological differences appear to play important roles in producing OBI. Therefore, this project was aimed to examine the expression of a chemokine receptor (CCR5) on CD8 T cells of OBI patients.Materials and methods: In this experimental study, 3,700 HBsAg- plasma samples were collected. Samples were tested for anti-HBc antibody and all of HBsAg-/anti-HBc+ samples were screened for HBV-DNA by PCR. HBV-DNA positive samples were assigned as OBI cases. Also, flow cytometry analysis was performed to examine the expression of CCR5 on CD8 T cells of OBI patients.Results: Results of current study showed that 352 (9.5%) cases of samples were positive for anti-HBc. Examination of HBsAg-/anti-HBc+ samples for HBV-DNA by PCR showed that 57 (16.1%) cases had HBV-DNA. Flow cytometric studies indicated lymphocytosis in these patients; however, the number of cells which expressed CD8 and CCR5 is decreased significantly in patients, compared to healthy control. In addition to CD8 T cells, the expression of CCR5 is also decreased on all immune cells.Conclusion: One of the chemokine receptors which are expressed by CD8+ T cells is CCR5 and these cells are recruited to infected tissues, including liver by CCR5. Therefore, based on results of this investigation, one may conclude that due to the decreased expression of CCR5, the CD8+ T cells are unable to respond to the chemokines (CCR5 ligands) and, hence, can not immigrate to the infected liver and incorporate in clearance of hepatitis B virus.J Mazand Univ Med Sci 2009; 19(68): 11-18 (Persian)

Aims Occult hepatitis B infection (OBI) may adversely affect the outcome of patients with chronic liver disease (CLD). There are no data on OBI and CLD in children. This study determined the prevalence and effect of OBI in HBsAg-negative CLD children. Materials and methods CLD children were prospectively evaluated with a demographic, clinical, and investigative proforma. All HBsAg-negative CLD cases were tested for exposure to hepatitis B (total anti-HBc, anti-HBs). Serum hepatitis B virus DNA was measured in exposed (total anti-HBc positive) patients. Results A total of 115 HBsAg-negative CLD children (59 boys, age 9.0±3.6 years) were enrolled. The etiology of CLD was known in 94 cases and 21 children had cryptogenic CLD. Of these, 45 (39.1%) had evidence of HBV exposure (23 total anti-HBc positive, 17 total anti-HBc and anti-HBs positive, five only anti-HBs positive without previous vaccination). The anti-HBc-positive children had a higher Child's score than the anti-HBc-negative children [11 (5-13) vs. 7 (5-13); P=0.00]. A total of 4/45 children had seropositive OBI with serum HBV DNA of 8, 36, 133, and 156 IU/ml, respectively. The proportion of total anti-HBc positivity (8/21 vs. 32/94; P=0.8) and OBI (2/21 vs. 2/94; P=0.1) was similar in cryptogenic CLD and known cause CLD. Conclusion Seropositive OBI is infrequent in Indian children with CLD. The prevalence is similar in cryptogenic and CLD of known etiology.

(Received 26 August, 2009 ; Accepted 18 Novamber, 2009)AbstractBackground and purpose: Occult hepatitis B infection (OBI) is a form of hepatitis in which despite the absence of detectable HBsAg, HBV-DNA is present in peripheral blood of patients. Investigators believed that the genetics and immunological parameters may be different in resistant individuals and patients. Cytokines, such as IL-12, could be leading to alteration in viral immune response. The main aim of this study was to investigate the serum level of IL12 in OBI patients.Materials and methods: In this study, the plasma samples of 3700 HBsAg negative blood donors were tested for anti-HBs by ELISA. The HBsAg negative and anti-HBc positive samples were selected and screened for HBV-DNA by PCR. HBV-DNA positive samples were assigned as OBI cases and ELISA technique were performed to examine the serum level of IL-12 in OBI and 100 healthy controls.Results: Our results showed that there was no significant difference in serum level of IL-12 between OBI patients and controls.Conclusion: In order to be clear of viruses, L-12 is increased in viral infection. Based on the results of this study, it is concluded that OBI patients can not produce enough IL-12 to clear HBV. J Mazand Univ Med Sci 2009; 19(72): 81-83 (Persian)

In this cross-sectional study, 207 hepatitis B surface antigen (HBsAg)-negative kidney transplant recipients were evaluated based on demographic and epidemiological data and on the levels of serological markers of hepatitis B virus (HBV) and hepatitis C virus infection and liver enzymes. Patients with HBV or human immunodeficiency virus infection were excluded. Sera were analysed for the presence of HBV-DNA. HBV-DNA was detected in two patients (1%), indicating occult hepatitis B (OHB) infection (the HBV-DNA loads were 3.1 and 3.5 IU/mL in these patients). The results of the liver function tests were normal and no serological markers indicative of HBV infection were detected. The prevalence of OHB infection was low among kidney transplant recipients, most likely due to the low HBsAg endemicity in the general population of the study area.

AIM To investigate the prevalence and virological characteristics of occult hepatitis B virus (HBV) infections in patients with hematological malignancies in South Egypt. METHODS Serum samples were collected from 165 patients with hematological malignancies to monitor titers of HBV DNA, hepatitis B surface antigen (HBsAg), and antibodies to HBV core (anti-HBc) and surface antigens. Serum samples negative for HBsAg and positive for anti-HBc were subjected to nucleic acid extraction and HBV DNA detection by real-time polymerase chain reaction. DNA sequences spanning the S region were analyzed in cases with occult HBV infection. In vitro comparative study of constructed 1.24-fold wild type and S protein mutant HBV genotype D clones was further performed. RESULTS HBV DNA was detected in 23 (42.6%) of 54 patients with hematological malignancies who were HBsAg negative, but anti-HBc positive, suggesting the presence of occult HBV infection. The complete HBV genome was retrieved from 6 occult HBV patients, and P120T and S143L were detected in 3 and 2 cases, respectively. Site directed mutagenesis was done to produce 1.24-fold genotype D clones with amino acid mutations T120 and L143. The in vitro analyses revealed that a lower level of extracellular HBsAg was detected by chemiluminescence enzyme immunoassay (CLEIA) with the clone containing T120 mutation, compared with the wild type or the clone with S143L mutation despite the similar levels of extracellular and intracellular HBsAg detected by Western blot. Southern blot experiments showed that the levels of intracellular HBV DNA were not different between these clones. CONCLUSION Occult HBV infection is common in patients with hematological malignancies and associated with P120T and S143L mutations. 120T mutation impairs the detection of HBsAg by CLEIA.

stopping NA treatment. Nobody had HBsAg loss. Of the patients with undetectable HBcrAg, 39% had HBsAg level of