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Background: Although nucleos(t)ide analogues (NAs) are thought to reduce the risk of hepatitis B virus (HBV)‐related hepatocellular carcinoma (HCC), the effect of NA discontinuation on the prognosis of HBV‐related HCC after hepatectomy is rarely reported. We aimed to investigate the potential for hepatitis B virus e antigen (HBeAg)‐negative HBV‐related HCC patients to discontinue NAs based on preoperative hepatitis B virus surface antigen (HBsAg) status. Methods: This historical cohort study involved 1232 NA‐treated HBeAg‐negative patients who underwent curative hepatectomy for HBV‐related HCC from 2014 to 2019. The recurrence‐free survival (RFS) and overall survival (OS) of patients discontinuing NAs before surgery were compared with those continuing NAs. Propensity score matching (PSM) was used to balance baseline characteristics. Results: Of all enrolled patients, 839 (68.1%) patients continued NAs, and 393 (31.9%) patients discontinued NAs. Continuation of NAs was identified as an independent risk factor for RFS (HR 2.047, 95% CI 1.348–3.109, p < 0.001 before PSM and HR 2.756, 95% CI 1.537–4.942, p < 0.001 after PSM) in HBsAg‐negative patients. Similarly, subgroup survival analyses showed that NA discontinuation was associated with better RFS (p = 0.029 before PSM and p < 0.001 after PSM) and comparable OS (p = 0.935 before PSM and p = 0.115 after PSM) than NA continuation in HBsAg‐negative patients. The interaction between HBsAg status and continuation or discontinuation of NAs was significant (p for interaction <0.001). Conclusions: These findings demonstrate the potential for HBeAg‐negative HBV‐related HCC patients who have achieved HBsAg seroclearance to discontinue NAs under strict monitoring. [ABSTRACT FROM AUTHOR]

A highly sensitive and reliable Hepatitis B virus surface antigen (HBsAg) measurement is essential to universal screening, timely diagnosis, and management of Hepatitis B virus (HBV) infection. This study aimed to evaluate the performance of MAGLUMI HBsAg chemiluminescence immunoassay (CLIA). MAGLUMI HBsAg (CLIA) was compared against ARCHITECT HBsAg. 411 HBsAg positive samples, including different stages of infection, genotypes, subtypes, mutants, and 30 seroconversion panels were tested to evaluate diagnostic sensitivity. Diagnostic specificity was evaluated by testing 205 hospitalized samples and 5101 blood donor samples. Precision, limit of blank (LoB), limit of detection (LoD), and linearity were also verified. The diagnostic sensitivity of the MAGLUMI HBsAg (CLIA) was 100% with better seroconversion sensitivity than ARCHITECT HBsAg. The MAGLUMI HBsAg (CLIA) has optimal detection efficacy for HBV subgenotypes samples. The analytical sensitivity is 0.039 IU/mL. The initial diagnostic specificity is 99.63% on blood donors and 96.59% on hospitalized samples. The verification data demonstrated high repeatability, a LoB of 0.02 IU/mL, LoD of 0.05 IU/mL and an excellent linearity of 0.050–250 IU/mL (R2 = 0.9946). The MAGLUMI HBsAg (CLIA) is proved a highly sensitive and reliable assay with optimal subgenotype detection efficacy. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Kunming Medical University / Kunming Yike Daxue Xuebao is the property of Kunming Medical Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Though the world-wide hepatitis B virus (HBV) vaccination program has been well completed for almost thirty years in many nations, almost HBV-related hepatocellular carcinoma (HCC) occurs in unvaccinated middle-aged and elderly adults. Apparently, treating 80% of qualified subjects could decrease HBV-related mortality by 65% in a short period. Nevertheless, globally, only 2.2% of CHB patients undergo antiviral therapy. The HBV markers related to HCC occurrence and prevention are as follows: the HCC risk is the highest at a baseline of HBV DNA of 6–7 log copies/mL, and it is the lowest at a baseline of an HBV DNA level of >8 log copies/mL and ≤4 log copies/mL (parabolic, and not linear pattern). The titer of an HBV core-related antigen (HBcrAg) reflecting the amount of HBV covalently closed circular DNA (ccc DNA) in the liver is related to HCC occurrence. The seroclearance of HBs antigen (HBsAg) is more crucial than HBV DNA negativity for the prevention of HCC. In terms of the secondary prevention of hepatitis B-related HCC involving antiviral therapies with nucleos(t)ide analogues (NAs), unsolved issues include the definition of the immune-tolerant phase; the optimal time for starting antiviral therapies with NAs; the limits of increased aminotransferase (ALT) levels as criteria for therapy in CHB patients; the normalization of ALT levels with NAs and the relation to the risk of HCC; and the relation between serum HBV levels and the risk of HCC. Moreover, the first-line therapy with NAs including entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF) remains to be clarified. Discussed here, therefore, are the recent findings of HBV markers related to HCC occurrence and prevention, unsolved issues, and the current secondary antiviral therapy for the prevention of HBV-related HCC. [ABSTRACT FROM AUTHOR]

Copyright of China Tropical Medicine is the property of China Tropical Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hepatitis delta virus (HDV) coinfected with HBV causes severe viral hepatitis, however, the number of HDV infection may be underestimated. In the present study, we enrolled 1,141,331 blood donations, routinely tested for HBsAg and/ or HBV DNA, from 21 blood establishments in China. 2,690 donors were HBsAg and/or HBV DNA positive after screening tests. After verification of HBsAg and HBV DNA, 1,490 samples were HBsAg confirmed-positive, including 1,459 HBV DNA-positive samples, and 825 samples were seronegative but HBV DNA positive. We first analyzed demographic characteristics of involved 2,690 donors with different HBV infection status and found the proportions of males, the older donors, workers and farmers were higher in HBsAg-/HBV DNA+ group. Then we evaluated specificity of HDV IgG and IgM antibody assays with 375 HBsAg and HBV DNA confirmed-negative samples, and 374 were tested negative using the two assays, respectively, suggesting a specificity of 99.73% for both assays (374/375, 95% Cl: 98.51–99.95%). Subsequently, we tested for HDV IgG and IgM of 2,315 HBsAg and/or HBV DNA confirmed-positive samples, and nine showed reactivity for IgG, while two were reactive for IgM. All these 11 reactive samples were tested again with another HDV pan-Ig and IgM testing assays and HDV RNA, and only one donor was identified as HDV IgG positive and HDV RNA negative, showing an HDV seroprevalence of 0.067% (95%CI: 0.012–0.38%) among HBsAg-positive blood donors in China. The positive donor was followed up for 2 years after the donation date, and decreased antibody titer of HDV IgG and HBsAg conversion were observed, and the infection status of the donor was HDV infection with recovery and occult hepatitis B virus infection with genotype C2. These results indicated a low seroprevalence of HDV infection among blood donors and a low risk of HDV transmission through blood transfusion in China. [ABSTRACT FROM AUTHOR]

Background: Hepatitis B virus surface antigen (HBsAg) is an important protein in both diagnosis and prevention of hepatitis B infection. In the current study, a piezoelectric immunosensor based on antibody-antigen interaction was designed to detect HBsAg. A quartz crystal microbalance system was employed to detect antibody-antigen interaction. Methods: At first, an oscillator was designed to measure the resonant frequency affected by the reactants using IC 74LVC1GX04. Antibody against HBsAg was immobilized on 10 MHz AT-cut quartz crystal. The surface modifications were monitored by atomic force microscopy (AFM) and contact angle measurements. Different concentrations of antibody were used for surface immobilization and the frequency shifts were assessed. The system stability was studied by evaluating the stability of the crystal and the immobilized antibody. The adsorption of antibody onto the crystal was analyzed using AFM and changes in the resonance frequency. Further, a direct immunoassay was performed with this immobilized antibody to identify HBsAg solutions at different concentrations. Finally, specific and non-specific responses were investigated using hepatitis B (HBsAg) and hepatitis C (HCV Ag) antigens, respectively. Results: Antibodies against HBsAg were successfully immobilized on 10 MHz AT-cut quartz crystal. The stability tests of crystal immobilized with antibody and unimmobilized crystal revealed that both forms of crystals were stable. Theoretical and experimental frequency assays were compared. A decrease in the contact angle indicated the hydrophilicity of surface after modifications. AFM images illustrated a more uniform surface after antibody adsorption and the surface roughness (RMS) reduced from 1.13 to 0.99 nm. Changes in the frequency were detected after the physical adsorption of HBsAb on the designed chip. The standard curve of antigen revealed the frequency changes depend on concentration of antigen. Finally, the specificity test confirmed the specificity of the designed biosensor for the detection of HBsAg from HCV Ag. The quantization of immobilized antibody was characterized by the frequency shift of the QCM. The obtained results were compared with ELISA assay. The correlation coefficients of HBsAg dilution between QCM and ELISA was 0.9821. Conclusions: This study is a new step to meet the challenges regarding HBsAg detection. Physical adsorption used in this study was effective as the simplest immobilization method to design a QCM-based immunosensor for HBsAg detection. Facilitated, fast, and simple detection of HBsAg by an antibody-based QCM biosensor is our main objective. [ABSTRACT FROM AUTHOR]

Background: Many efforts are currently focused on functional treatment of the hepatitis B virus (HBV). This can be done by suppressing the secretion of HBV surface antigen (HBsAg). Scientific communities are very interested in natural products in that respect. Objective: Use of root extract of Havachoobe (Onosma dichroanthum BoissI), a Northern Iranian native medical herb, for assessment of its anti-HBsAg secretion activity. Methods: Havachoobe had been bought at a nearby apothecary store. Plant root extract was obtained using a hydroalcoholic process. Cytotoxic activity of the extract was examined on PLC/PRF/5 cells using MTT assay. ELISA has been used to measure HBsAg in the treated cell line supernatants. In addition, real-time PCR analysis was performed to evaluate the expression of HBsAg before and after treatment of Onosma in vitro. Results: The results showed very low root extract cytotoxicity at concentrations under 8 μg/mL. Tissue culture infectious dose 50 was obtained at 63.78 μg/mL. In a dose-dependent and time-dependent manner, a significantly reduced HBsAg secretion was observed at a concentration of 8 ppm at 12 h post-treatment. The real-time PCR result showed relative decreased HBsAg expression at all doses at 12 h post-treatment time. Discussion: In this study, we first reported anti-HBsAg activity on an Iranian herbal medicine. Havachoobe root extract was shown to be able to inhibit HBsAg in a dose-dependent and time-dependent manner. We find the extract exerts its inhibitory effect of HBsAg by targeting transcription of HBsAg. [ABSTRACT FROM AUTHOR]

For personalized treatment of chronic HBV-infected patients, it is necessary to identify hepatitis B virus (HBV) surface antigen (HBsAg) subtypes and HBV genotypes circulating among infected individuals. To this end, a laboratory version of the test kit for HBsAg subtype and HBV genotype identification in human blood serum/plasma using enzyme-linked immunosorbent assay (ELISA) and a custom monoclonal antibody (MAb) panel has been developed. With this kit version, it appears possible to identify the main HBsAg subtypes (ayw2, ayw3, adw2, and adrq+) and HBV genotypes (A, C, and D) circulation in Russian Federation. The aim of the work was to test the laboratory-developed ELISA kits for HBsAg subtyping and HBV genotyping in human HBsAg-positive blood plasma samples. A total of 146 HBsAg-positive plasma samples were tested. For 108 samples with detectable viral DNA, the results of HBsAg subtyping and HBV genotyping using the suggested MAb panel were compared with the results of genomic DNA sequencing for HBV isolates. For 38 HBsAg-positive samples in which HBV DNA could not be detected, ELISA, using the highly specific MAb panel kindly provided by P. Swenson, PhD, was employed as a reference technique. The study demonstrated that for the group of HBsAg-positive samples with detectable HBV DNA, the coincidence between the results obtained using the suggested MAb panel and the results of HBV DNA genome sequence analysis was 85% for HBsAg subtyping and 98% for HBV genotyping. For the group of HBsAg-positive samples with undetectable HBV DNA, the coincidence between the two techniques (the one using the suggested MAb panel and one using Swenson's MAb panel) was 95% in the case of HBsAg subtyping and 100% for HBV genotyping. The reported results allow recommending the suggested laboratory ELISA test kit for HBsAg subtype and HBV genotype identification in human blood plasma as an alternative or a complementary technique to genomic analysis in order to study HBV characteristics especially in those cases when HBV DNA isolation appears impossible. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Modern Laboratory Medicine is the property of Journal of Modern Laboratory Medicine Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Transfusion-transmissible hepatitis B virus (HBV) infection is a major problem worldwide. Recently, confirmatory nucleic acid tests (NATs) for HBV DNA have been employed in several countries. We assessed the prevalence and yearly trends of HBV infection in blood donors in the Eastern Province of Saudi Arabia, screening for HBV surface antigen (HBsAg), antibody against HBV core antigen (anti-HBc), and HBV DNA. Methods: Between 2011 and 2015, a total of 22,842 donors were screened for HBsAg, anti-HBc, and HBV DNA using the HBsAg Qualitative II kit (Abbott, Ireland Diagnostics Division, Sligo, Ireland), ARCHITECT Anti-hepatitis B core antigen antibody (HBc) II Assay kit (Abbott GmbH & Co. KG, Wiesbaden, Germany), and NAT Procleix Ultrio Elite Assay kit (Grifols Diagnostic Solutions Inc., Los Angeles, CA, USA), respectively. Results: A total of 739 (3.24%) donors were HbsAg(+), anti-HBc(+), or HBV DNA(+); 63 (0.28%) were HbsAg(+), anti-HBc(+), and HBV DNA(+). Twelve (0.05%) were anti-HBc(+) and HBV DNA(+) but HBsAg(-); they were considered to have occult infection. Further, 664 (2.91%) were HBsAg(-) but anti-HBc(+), indicating chronic or resolving infection. HBV prevalence increased significantly from 2011 to 2012, increased marginally till 2013, and showed a decreasing trend from 2013 (P >0.05). Conclusions: The five-year prevalence of HBV infection among blood donors in the Eastern Province of Saudi Arabia (3.24%) is lower than that reported for other regions in the country. The occult HBV infection rate of 0.05% emphasizes the importance of NATs in isolating potential infectious blood units. [ABSTRACT FROM AUTHOR]

Abstract: A critical challenge in producing an antibody‐based assay with the highest reproducibility and sensitivity is the strategy to immobilize antibodies to solid phase. To date, numerous methods of antibody immobilization were reported but each was subjected to its advantages and limitations. The current study proposes a new potential antibody binding protein, the human neonatal fragment crystallizable (Fc) receptor. This protein has shown its high affinity to the Fc of antibody either in vivo or in vitro. Human neonatal Fc receptor is a heterodimer constructed by p51 α‐heavy chain and β2‐microglobulin light chain; however, the binding sites toward the antibody are located in the p51 α‐heavy chain. Hence, vector cloning and recombinant protein expression were carried out to express the p51 α‐heavy chain of the human neonatal Fc receptor (hFcRn‐α). The recombinant protein expressed, hFcRn‐α, was adopted to pin rabbit IgG against hepatitis B virus surface antigen to a solid phase. A sandwich enzyme‐linked immunosorbent assay was further developed to evaluate the efficiency of hFcRn‐α‐directed immobilization in antigen detection. The result was compared with the conventional physical adsorption method. The findings demonstrated that human neonatal Fc receptor was efficient in pinning antibodies and generating higher signals compared with the physical adsorption of antibody. [ABSTRACT FROM AUTHOR]

Abstract: A sensitive electrochemical immunosensor for Hepatitis B virus surface antigen (HBsAg) detection was fabricated based on hemin/G‐quadruplex interlaced onto Fe3O4‐AuNPs or hemin ‐amino‐reduced graphene oxide nanocomposite (H‐amino‐rGO‐Au). G‐quadruplex DNAzyme, which is composed of hemin and guanine‐rich nucleic acid, is an effective signal amplified tool for its outstanding peroxidase activity and Fe3O4‐AuNPs or (H‐amino‐rGO‐Au) nanocomposites with quasi‐enzyme activity provide appropriate support for the immobilization of hemin/G‐quadruplex. The target protein was sandwiched between the primary antibody immobilized on the GO and secondary antibody immobilized on the Fe3O4‐AuNPs or (H‐amino‐rGO‐Au) nanocomposites and glutaraldehyde was used as linking agent for the immobilization of primary antibody on the surface of GO. Both Fe3O4‐AuNPs and H‐amino‐rGO‐Au nanocomposite and also hemin/G‐quadruplex can cooperate the electrocatalytic reduction of H2O2 in the presence of methylene blue as mediator. The proposed immunosensor has a wide linear dynamic range of 0.1 pg/ml to 300 pg/ml with a detection limit of 60 fg/ml when Fe3O4‐AuNPs was used for immobilization of hemin/G‐quadruplex, while the dynamic range and DL were 0. 1–1000 pg/mL and 10 fg/mL, respectively in the presence of H‐amino‐rGO‐ Au nanocomposite as platform for immobilizing of hemin/G‐quadruplex. The proposed immunosensor was also used for analysis of HBsAg in spiked human serum samples with satisfactory results. [ABSTRACT FROM AUTHOR]

The replication of hepatitis B virus (HBV) may be modulated by a variety of cell signaling pathways, including the phosphatidylinositol 3‑kinase (PI3K)‑RAC‑α serine/threonine‑protein kinase (AKT)‑serine/threonine‑protein kinase mTOR (mTOR) pathway. The aim of the present study was to determine the regulatory effects of this pathway on the infection and replication of HBV. The results indicated that the HBV entry process may activate the AKT pathway, as demonstrated by AKT phosphorylation in HBV natural infection. However, inhibition of AKT phosphorylation by short‑term treatment with AKT inhibitors was unable to block HBV entry, which suggested that AKT activation induced by HBV infection is not essential for viral entry process. Prolonged treatment with PI3K‑AKT‑mTOR pathway inhibitors markedly promoted HBV replication in HBV replicating and natural infection models. The PI3K‑AKT‑mTOR pathway was therefore identified to be a negative regulator of HBV replication. These inhibitors enhanced the replication and transcription of HBV in an HBx‑dependent way. The results additionally indicated that a PI3K inhibitor, Ly294002, inhibited the secretion of the small surface antigen of HBV in a PI3K‑AKT‑independent manner. The inhibitor Ly294002 may be used as a tool for the drug development of surface antigen secretion inhibitors. [ABSTRACT FROM AUTHOR]

Background: Hepatitis B is the world's most common serious liver infection. Infection by hepatitis B virus during pregnancy has high rate of vertical transmission and adverse effect on both the mother and child. Data on seroprevalence and associated factors among pregnant women in Dawuro or surrounding was scarce. Therefore, the aim of this study was to assess prevalence of hepatitis B virus and factors associated among pregnant women in Dawuro Zone. Methods: Institution based cross-sectional study was conducted from 1st April to May 31, 2015 in Dawuro zone. Venous blood was collected, plasma was separated and hepatitis B virus surface antigen was screened using rapid test. Logistic regression was employed with 95% CI and p value of <0.05 was used as statistically significant. Results: Data were collected on 289 women. The overall prevalence from this study was (p=3.5%, 95% CI 1.4-5.6%) multivariate analysis using logistic regression showed multiple sexual partner (AOR=6.923; 95% CI 1.685-28.441), and abortion history (AOR = 4.975; 95% CI 1.21-20.456), were significantly associated with hepatitis B virus surface antigen (HBsAg) infection. Conclusion: This seroprevalence was categorized as intermediate endemicity according to WHO classification criteria. Health education on sexual transmission of hepatitis B virus and inclusion of screening hepatitis b virus as routine antenatal care service is recommended. [ABSTRACT FROM AUTHOR]

Background: Although Egypt had adopted implementation of routine infant hepatitis B virus (HBV) vaccination in 1992, its effectiveness is not evaluated on a national scale. Assessment of early and long-term seroprotection after compulsory vaccination is an important measure for monitoring the success of the vaccination program. Aim: The aim of this study was to assess HBV seroprotection and immune memory in children and adolescents who were vaccinated during infancy in Cairo Governorate. Materials and Methods: The study was carried out in two phases. The first phase was a cross-sectional study carried out in five districts in Cairo Governorate, recruiting 819 children in the age range of 9 months to 16 years. All children had received full doses of the compulsory HBV vaccination. Serum samples were taken from each child and assessed for antibody against hepatitis B virus surface antigen (anti-HBs) titer; total antibodies against HBV core antigen, and HBV surface antigen. HBV DNA was investigated by real-time PCR for those who were HBV core antigen or HBV surface antigen positive. In the second phase, nonseroprotected children (anti-HBs <10 IU/l) received HBV booster dose. Anti-HBs titer was reassessed after 4 weeks to identify anamnestic response. Individuals showing antibody concentrations of less than 10 IU/l were then given an additional complete course of vaccination. Results: Four out of 819 children had HBV breakthrough infection. The seroprotection rate was 60.7%, and was significantly higher among children aged less than 5 years compared to the older age groups and among boys compared to girls. Multivariate logistic analysis showed age as the only independent predictor of low anti-HBs titer. About 95% of nonseroprotected children developed anamnestic response postbooster. Anti-HBs geometric mean titer (GMT) increased significantly from pre-booster (13.8±16.9IU/L) compared to post-booster (307±6.0IU/L, P<0.001). Anti-HBs GMT was significantly higher among children with prebooster anti-HBs level =1 IU/l (424.9±4.4 IU/l) compared to children with undetectable level (178.3±8.3). Conclusion: Despite waning of anti-HBs over time, long-term protection still exists. The high anamnestic response rate signifies the existence of immune memory and giving a booster dose is not recommended. However, we suggest that prolonged follow up and surveillance of vaccinees immunized at an early age should be continued. [ABSTRACT FROM AUTHOR]

In this paper, a novel time-resolved fluorescence immunoassay (TRFIA) is described that allows the simultaneous quantitative detection of hepatitis B virus surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) in human serum to aid the diagnosis and monitoring of hepatitis B virus infection. The proposed method was developed based on a two-step sandwich immunoassay protocol in which monoclonal antibodies against HBsAg and HBeAg were co-coated in 96 microtitration wells, then tracer polyclonal antibodies against HBsAg labeled with samarium and tracer monoclonal antibodies against HBeAg labeled with europium chelates were used for detection. The detection range was 0.1-150 IU/mL for HBsAg and 0.5-160 PEIU/mL for HBeAg, and the detection limits were 0.03 IU/L and 0.09 PEIU/ml, respectively. The intra- and inter-assay coefficients of variation were below 8 % for both virus antigens. The dilution linearity and accuracy of the assay were satisfactory. No statistically significant differences were observed in sensitivity or specificity for the serum samples between the dual-label TRFIA and a commercial single-label TRFIA. These results demonstrate that an effective, reliable and convenient HBsAg/HBeAg dual-label TRFIA was successfully developed that may be clinically applicable for blood screening to monitor the course of hepatitis B virus infection and predict treatment responses. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the in vitro effects of hepatitis B virus surface antigen (HBsAg) on the immune function of human monocyte-derived dendritic cells (MD-DCs), and the moderating role of T cell immunoglobulin and mucin domain-containing molecule-3 (Tim-3) signaling molecule. The monocytes, obtained from healthy adult peripheral blood, were incubated with recombinant human granulocyte-macrophage colony-stimulating factor and interleukin (IL)-4 to induce DCs. DC-associated cell markers were detected using flow cytometry. MD-DCs were treated with HBsAg (5 μg/ml) in vitro for 48 h and subsequently, cell markers, lymphocyte stimulatory capacity, signaling protein and downstream cytokines were assessed. In addition, a Tim-3 monoclonal antibody was used to inhibit the Tim-3 signaling pathway, and subsequently the immune responses of MD-DCs to HBsAg stimulation were determined using the aforementioned method. The cell phenotype expressions of MD-DCs were all significantly increased with cluster of differentiation (CD)11c at 70.09±0.57%, human leukocyte antigen-DR at 79.83±2.12%, CD80 at 48.33±7.34% and CD86 at 44.21±5.35%. The treatment of MD-DCs with HBsAg resulted in a CD80 and CD86 enhanced expression, enhanced lymphocyte stimulatory capacity, upregulated expression of Tim-3 and nuclear factor-κB (NF-κB), as well as enhanced cytokine secretion of IL-6, IL-10 and interferon (IFN)-γ. However, a reduced immune response of MD-DCs in response to HBsAg stimulation was observed when the Tim-3 signaling pathway was inhibited prior to stimulation. The expression of NF-κB was decreased and the cytokine secretion level of IL-6, IL-10 and IFN-γ were downregulated. The treatment with HBsAg in vitro resulted in an enhanced immune response of MD-DCs, which may be positively regulated by the Tim-3 signaling molecule. [ABSTRACT FROM AUTHOR]

Objectives In the case of coinfection with HIV and hepatitis B virus ( HBV) and/or hepatitis C virus ( HCV), hepatic disease progression is often accelerated, with higher rates of liver cirrhosis and liver-related mortality. We aimed to evaluate the performance of the rapid tests used routinely to detect HBV surface antigen ( HBsAg) and anti- HCV among HIV-infected patients in Guinea- Bissau. Methods Blood samples from HIV-infected patients in Guinea- Bissau were stored after testing for HBsAg and anti- HCV with rapid tests. Samples were subsequently re-tested for HBsAg and anti- HCV in Denmark. Results Two rapid tests were used in Guinea- Bissau: HBsAg Strip Ref 2034 ( VEDA. LAB, Alençon, France; sensitivity 62.3%; specificity 99.2%) and HEPA-SCAN ( Bhat Bio- Tech, Bangalore, India; sensitivity 57.1%; specificity 99.7%). In the two tests the ability to obtain the correct outcome depended on the antigen and antibody concentrations, respectively. Sex, age, CD4 cell count and antiretroviral therapy status did not differ between false negative and true positive samples in either of the tests. The study is limited by a low number of anti- HCV positive samples. Conclusions New diagnostic rapid tests should always be evaluated in the setting in which they will be used before implementation. [ABSTRACT FROM AUTHOR]

Occult hepatitis B virus infection (OBI) is highly prevalent worldwide. In some cases, it is a consequence of infection with variant viruses mutated in the S gene and producing a surface antigen not recognized by diagnostic kits. In most cases, OBI is due to a strong inhibition of hepatitis B virus (HBV) activities exerted by host defense mechanisms. OBI may reactivate in patients undergoing immunosuppressive therapy and/or chemotherapy with the possibility of a consequent development of acute hepatitis that may lead to hepatic failure. Hematological malignancies and therapeutic schedules including rituximab are the conditions most frequently associated with OBI reactivation. However, this event may occur in a large number of additional clinical and therapeutic settings. Identification of patients prone to undergo reactivation is of great importance for promptly starting a proper antiviral therapy that may stop the HBV reactivation and prevent its clinical sequelae. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

DNA damage response and repair pathways are important barriers to carcinogenesis. Here, we show that promyelocytic leukaemia ( PML, also known as TRIM19), involved in sensing DNA damage and executing homologous recombination repair, is down-regulated in non-tumour liver cells surrounding hepatitis B virus ( HBV)-related hepatocellular carcinoma ( HCC). No PML mutation or deletion was found in HBV-infected liver or HCC cells. Immunohistochemical analysis of liver biopsies from patients with breast or liver cancer and HBV reactivation after chemotherapy revealed PML up-regulation and HBV exacerbation in normal liver tissue in response to DNA damage (functional PML), PML down-regulation in HCC peritumour cells associated with high HBsAg accumulation and low HBV replication activity (suppressive PML), and heterogeneous nuclear PML expression in HCC cells that lost HBV DNA and HBsAg and were non-reactive to DNA damage (dysregulated PML). Loss of PML in HBsAg-transgenic mice promoted chromosome breaks in liver cells and accelerated the accumulation of body and liver fat and the development of a liver steatosis-dysplasia-adenoma-carcinoma sequence in an inflammation-independent and male-predominant manner, compared to PML knock-out or HBsAg-transgenic mice during the same time period. These results indicate that PML deficiency facilitates genomic instability and promotes HBsAg-related hepatocarcinogenesis, which also involves androgen and lipid metabolism. These findings uncover a novel PML link between HBV-related tumourigenesis, DNA repair, and metabolism. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We developed a fluorescence-activated cell sorter (FACS)-based immunoassay using Escherichia coli with autodisplayed Z-domains as a solid support for detection antibodies as well as a method to optimize the signal-to-noise ratio of fluorescence signals from E. coli. To improve the sensitivity of FACS measurements by eliminating artifactual signals from unrelated small particles in the sample mixture, E. coli with autodisplayed Z-domains was modified to express enhanced green fluorescence protein (eGFP) in the cytosol. By selectively gating the measurement channel for eGFP in the cytosol, we were able to discriminate between green fluorescent E. coli and artifact particles. We confirmed the efficacy of this optimization method for FACS-based immunoassay using several model reactions. Finally, as proof of concept, we used the FACS-based immunoassay and our optimization method for the medical diagnosis of human hepatitis B virus surface antigen. [ABSTRACT FROM AUTHOR]

ABSTRACT Time-resolved fluorometry of lanthanide chelates is one of the most useful non-isotopic detection techniques and has been used in numerous applications in biomedical science. We developed a time-resolved fluoroimmunoassay (TRFIA) to quantify α-fetoprotein (AFP) and hepatitis B virus surface antigen (HBsAg) in human serum. Based on a two-site sandwich protocol, monoclonal antibodies (McAbs) against AFP and HBsAg were co-coated in 96 microtitration wells and tracer McAbs against HBsAg and AFP were labeled with europium (Eu) and samarium (Sm) chelates, respectively. After application of diluted serum samples, Eu3+- and Sm3+-McAbs were added and fluorescence signals of Sm3+ and Eu3+ tracers were collected. Detection limits of AFP and HBsAg were 0.09 mIU/L and 0.01 µg/L, respectively. Measurement ranges of AFP-TRFIA and HBsAg-TRFIA were 1-1000 mIU/L and 0.2-150 µg/L, respectively. Intra- and inter-assay coefficients of variation of AFP-TRFIA were 3.3-4.1% and 5.7-7.2% and for HBsAg-TRFIA were 2.9-3.9% and 4.9-6.8%, respectively. Linear correlation of TRFIA and chemiluminescence immunoassay measurements resulted in a correlation coefficient of 0.9949 for AFP and 0.9940 for HBsAg. For the endurance test, Eu-labeled McAbs were stable for at least one year at −20°C and the results of the TRFIA with the same reagents were also reproducible after one year. The availability of a highly sensitive, reliable and convenient AFP/HBsAg TRFIA will allow the quantification of both AFP and HBsAg, thereby providing diagnostic value in various clinical conditions and could be applied for clinical use. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Purpose: Measurement of serum hepatitis B virus surface antigen (HBsAg) levels is important for the management of chronic hepatitis B patients in terms of monitoring response to antiviral therapy. This study aimed to evaluate the diagnostic performance of a new diagnostic kit, which quantitatively measures serum HBsAg level using an immunoradiometric assay (IRMA)-based method. Measurements were compared with those obtained using a chemiluminescent microparticle immunoassay (CMIA)-based method. Methods: The blood samples of 96 patients with chronic hepatitis B were used in this study. Copy numbers of serum hepatitis B virus (HBV) DNA were determined in 23 of these samples. The correlation between and the concordance of IRMA and CMIA results were determined using Pearson's correlation coefficients. P values of 0.05 were considered to be statistically significant throughout. Results: Laboratory diagnoses based on IRMA were wholly in agreement with those based on CMIA. Furthermore, serum HBsAg levels by IRMA were found to be highly correlated with those determined by CMIA (correlation coefficient R = 0.838, p < 0.001). Serum HBsAg level and serum HBV DNA copies were found to be linearly related by both methods ( R = 0.067, p = 0.316 by IRMA, and R = 0.101, p = 0.215 by CMIA). Conclusion: The diagnostic performance of the investigated IRMA method of determining HBsAg levels was found to be comparable with that of a CMIA-based method in chronic hepatitis B patients. [ABSTRACT FROM AUTHOR]

To check feasibility and effectiveness of the α-amylase reporter system, two vectors were designed and tested using hepatitis B virus surface antigen (HBsAg) and Homo sapiens granulocyte-macrophage colony stimulating factor 2 (hGM-CSF2) as a model. By integrating the vector containing two independent cassettes into the same genome locus, high-producing clones of HBsAg (or hGM-CSF2) were screened using the α-amylase as a reporter. Results show there was a positive correlation (Correlation coefficient, R > 0.95) between the yield of recombinant proteins and the α-amylase activity of corresponding transformants, which was independent of the gene dosage. [ABSTRACT FROM AUTHOR]

Summary: Expenditure on screening blood donations in developing countries can be reduced by testing donations in pools. This study evaluated serological screening in pools for hepatitis B virus (HBV) at the Israeli national blood bank and a hospital blood bank in Gaza, the Palestinian Authority. The accuracy of HBV surface antigen (HBsAg) enzyme immunoassay performed on pools of 3–24 samples was compared with individual tests. Delay in detecting positive samples due to dilution in pools and the possibility of antibody-antigen neutralization were analyzed. The sensitivity of pooled testing for HBsAg was 93–99%, prolonging the window period by 5 days (8.3%). Neutralization of HBsAg by hepatitis B surface antibodies (anti-HBs) could be minimized by testing immediately after pooling. Serological testing for HBsAg in pools may be performed using manually created pools of up to six samples, with 5% loss in sensitivity and a risk of neutralization by anti-HBs present in the donor population. Pooling can therefore be considered as an option only in countries with a low prevalence of HBV. [Copyright &y& Elsevier]

The small (S) envelope protein is the major component of hepatitis B virus surface antigen (HBsAg). Some mutations in the S-HBsAg coding region may cause deficiency in the secretion of both viral and empty subviral particles (SVPs) and lead to accumulation of HBsAg inside the cells. In this study, we identified a unique amino acid substitution (L215Q) in the carboxyl-terminal end of S-HBsAg of an HBV genotype F isolate that provoked an inhibitory effect on secretion of SVPs. HBsAg levels were measured daily by enzyme-linked immunosorbent assay in the medium and cell extracts of HuH7 and CHO cells transiently transfected with plasmids containing wild-type or mutated S-HBsAg gene. Wild-type HBsAg was detectable in both medium and cell extracts of transfected cells. In contrast, extracellular levels of mutant HBsAg were not higher than cut-off values. By immunofluorescence with monoclonal antibody, it was shown that wild-type HBsAg was distributed throughout the cytoplasm, whereas mutant HBsAg was concentrated around the nucleus, suggesting retention in the endoplasmic reticulum. Amino acid substitutions that inhibit HBsAg secretion, such as that characterized in this study (L215Q), should have implications in HBV immunological diagnostics. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Hepatitis B virus surface antigen (HBsAg), a specific antigen on the membrane of hepatitis B virus (HBV)-infected cells, provides a perfect target for therapeutic drugs. In order to mediate successful targeted delivery of these therapies, it is essential to have antibodies that recognize HBsAg with high specificity and affinity. In this report, we constructed a natural immune antigen binding fragments (Fab) antibody phage display library against HBsAg and after three rounds of panning, five Fab fragments with significant HBsAg binding ability were selected and analysed. DNA sequencing revealed that all the light chains had the same sequence, while all the Fd genes exhibited different sequences. For further application, all of the Fab antibodies were reconstructed into single chain antibodies (scFvs) and expressed in Escherichia coli BL21 cells. Indirect enzyme-linked immunosorbent assay analysis demonstrated that all five scFvs maintained a high affinity for HBsAg and could bind HBsAg on the membrane of HBV-infected cells. Indirect fluorescent staining analysis revealed that one of the scFvs (scFv15) could be internalized into HBsAg-positive HepG2.2.15 cells through clathrin-mediated endocytosis pathway. The internalizing scFv15 antibody would have great potential for the targeted delivery of therapeutics to HBV-infected cells. [ABSTRACT FROM AUTHOR]

Objective: We have reexamined hepatitis B virus subtypes to determine the role of specific HBsAg amino acids in serologic reactivity because of problematic genotype/subtype associations seen in a set of geographically diverse serum specimens. Methods: We obtained DNA sequences for 491 HBsAg-positive specimens from geographically distinct locations, determined their genotypes through phylogenetic analysis, and subtyped the specimens using an algorithm derived from published data on the molecular basis of HBsAg subtype reactivity. Problematic samples were subtyped serologically to resolve conflicts based on the amino acid sequence alone. Results: Three isolates were found to have unusual genotype/subtype associations. Examination of the isolates’ amino acid sequences suggested amino acid positions 122, 127, 140, 159 and 160 can be used to determine subtype reactivity from HBsAg amino acid sequences, while position 134, previously thought to play a role, is no longer important. Conclusions: This re-examination of hepatitis B virus subtypes shows the involvement of amino acid positions 122, 127, 140, 159 and 160 in HBsAg reactivity. While d, y, and r reactivities are controlled by single amino acid changes, w reactivity is determined by positions 122, 127, 140, and 159. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The antigenic “a” determinant of the human hepatitis B virus surface antigen (HBsAg) is highly conserved and involved in inducing neutralizing antibody. Mutations on this determinant have been associated with the hepatitis B virus (HBV) escape from vaccination but are also found in chronic HBV carriers, but their involvement in liver diseases including hepatocellular carcinoma (HCC) is unclear. To investigate the possible liver disease-associated role of HBsAg mutants, their incidence was analyzed in 11 paraffin embedded HCC tissues using an improved DNA extraction method. Mutations on the “a” determinant (Thr126Ser, Gly145Arg, a double mutant Thr126Ser/Gln129Asn, Met133Leu and Thr140Ile) were identified in 5 samples while the wild type sequence was found in 2 others. Future characterization of these HCC-associated HBsAg mutants should provide new insights on their role in the pathogenesis of HCC. [ABSTRACT FROM AUTHOR]

The present studies examined the cytotoxic activities of peripheral blood lymphocytes (PBL) from volunteers with (sero-positive) and without (sero-negative) circulating antibodies to hepatitis B virus surface antigen before and 30 days after vaccination with hepatitis B virus surface antigen (HBsAg). Long-term culture of monospecific hepatitis B surface (HBsAg)-responsive T-lymphocytes were isolated and grown in large numbers. The mechanism of T-cell mediated cytolysis, and the identification of the carbohydrate determinants on the surface of these effector cells responsible for the killing effect, are being examined. [ABSTRACT FROM AUTHOR]

To assess whether a different IgG subclass distribution was elicited in “low” and “high responders” after vaccination with recombinant hepatitis B virus surface antigen, we selected from 360 vaccine recipients 30 “lowresponder” subjects, with anti-HBs levels of 10–160 mIU/ml, and 40 “high-responder” subjects, with anti-HBs levels greater than 10,000 mIU/ml. In both groups all IgG subclasses were elicited in the anti-HBs response and the greatest contribution was that of IgG 1, followed by IgG2. IgG l was significantly less represented after the second (58%) and third doses (61%) of vaccine in “low responders” compared with “high responders” (65% and 69%). The relative percentage of IgG2 was significantly higher after the second (33%) and third (30%) doses of vaccine in “low responders” than in “high responders” (29% and 26%). In “low responders” the age of vaccine recipients significantly influenced the anti-HBs IgG subclass distribution: IgG2 and IgG4 production was positively correlated with age, whereas the opposite was observed for IgGl. These data support the evidence that: (1) IgGl and IgG2 subclasses are mainly involved in the specific anti-HBs response both in “high” and “low responders”; (2) the relative contribution of specific IgG2 to vaccination is higher in low responders and progressively increases with age. [ABSTRACT FROM AUTHOR]