Hepatitis B surface antigen-negative but hepatitis B envelope antigen-positive false occult hepatitis B virus infection:A case report

BACKGROUND Occult hepatitis B infection(OBI)is characterized by the detection of hepatitis B virus(HBV)DNA in serum(usually HBV DNA<200 IU/mL)or the liver but negativity for hepatitis B surface antigen(HBsAg).The diagnosis of OBI relies on the sensitivity of assays used in the detection of HBV DNA and HBsAg.HBsAg assays with inadequate sensitivity or inability to detect HBV S variants may lead to misdiagnosis of OBI in people with overt HBV infection.CASE SUMMARY We report a HBsAg-negative but hepatitis B envelope antigen-positive patient who had a significant HBV DNA level.The patient was initially diagnosed as having OBI.However,sequence analysis revealed a unique insertion of amino acid residues at positions 120-124 in the S protein,which affects the formation of a disulfide bond that is associated with the formation of a loop.It is well known that there is an overlap between the S protein and Pol protein.We found that this new insertion site occurred in polymerase/reverse transcriptase domain,indi-cating that this insertion might be involved in HBV pathogenicity.The patient was finally diagnosed with a false OBI.CONCLUSION An insertion of amino acid residues at positions 120-124 of the S protein affects the formation of immunodominant epitopes and results in negative HBsAg levels.

Quantitative hepatitis B core antibody and quantitative hepatitis B surface antigen:Novel viral biomarkers for chronic hepatitis B management

The management of hepatitis B virus(HBV)infection now involves regular and appropriate monitoring of viral activity,disease progression,and treatment response.Traditional HBV infection biomarkers are limited in their ability to predict clinical outcomes or therapeutic effectiveness.Quantitation of HBV core antibodies(qAnti-HBc)is a novel non-invasive biomarker that may help with a variety of diagnostic issues.It was shown to correlate strongly with infection stages,hepatic inflammation and fibrosis,chronic infection exacerbations,and the presence of occult infection.Furthermore,qAnti-HBc levels were shown to be predictive of spontaneous or treatment-induced HBeAg and HBsAg seroclearance,relapse after medication termination,re-infection following liver transplantation,and viral reactivation in the presence of immunosuppression.qAnti-HBc,on the other hand,cannot be relied on as a single diagnostic test to address all problems,and its diagnostic and prognostic potential may be greatly increased when paired with qHBsAg.Commercial qAnti-HBc diagnostic kits are currently not widely available.Because many methodologies are only semi-quantitative,comparing data from various studies and defining universal cut-off values remains difficult.This review focuses on the clinical utility of qAnti-HBc and qHBsAg in chronic hepatitis B management.

Immunoprophylaxis failure and vaccine response in infants born to mothers with chronic hepatitis B infection in Djibouti

BACKGROUND In endemic areas,vertical transmission of hepatitis B virus(HBV)remains a major source of the global reservoir of infected people.Eliminating mother-to-child transmission(MTCT)of HBV is at the heart of World Health Organization’s goal of reducing the incidence of HBV in children to less than 0.1%by 2030.Universal screening for hepatitis B during pregnancy and neonatal vaccination are the main preventive measures.AIM To evaluate the efficacy of HBV vaccination combined with one dose of immunoglobulin in children born to hepatitis B surface antigen(HBsAg)-positive mothers in Djibouti city.METHODS We conducted a study in a prospective cohort of HBsAg-positive pregnant women and their infants.The study ran from January 2021 to May 2022,and infants were followed up to 7 mo of age.HBV serological markers and viral load in pregnant women were measured using aVidas microparticle enzyme-linked immunosorbent assay(Biomérieux,Paris,France)and the automated Amplix platform(Biosynex,Strasbourg,France).All infants received hepatitis B immunoglobulin and were vaccinated against HBV at birth.These infants were closely monitored to assess their seroprotective response and for failure of immunoprophylaxis.Simple logistic regression was also used to identify risk factors associated with immunoprophylaxis failure and poor vaccine response.All statistical analyses were performed with version 4.0.1 of the R software.RESULTS Of the 50 pregnant women recruited,the median age was 31 years,ranging from 18 years to 41 years.The MTCT rate in this cohort was 4%(2/50)in HBsAg-positive women and 67%(2/3)in hepatitis B e antigen-positive women with a viral load>200000 IU/mL.Of the 48 infants who did not fail immunoprophylaxis,8(16%)became poor responders(anti-HB<100 mIU/mL)after HBV vaccination and hepatitis B immunoglobulin,while 40(84%)infants achieved a good level of seroprotection(anti-HB>100 mIU/mL).Factors associated with this failure of immunoprophylaxis were maternal HBV DNA levels(>200000 IU/mL)and hepatitis B e antigen-positive status(odds ratio=158,95%confidence interval:5.05-4958,P<0.01).Birth weight<2500 g was associated with a poor immune response to vaccination(odds ratio=34,95%confidence interval:3.01-383.86,P<0.01).CONCLUSION Despite a failure rate of immunoprophylaxis higher than the World Health Organization target,this study showed that the combination of immunoglobulin and HBV vaccine was effective in preventing MTCT of HBV.Therefore,further studies are needed to better understand the challenges associated with immunoprophylaxis failure in infants in Djibouti city.

Transformation of hepatitis B serologic markers in babies born to hepatitis B surface antigen positive mothers

AIM:To better understand the clinical significance of hepatitis B seroiogic markers in babies born to hepatitis B surface antigen (HBsAg) positive mothers, the incidence of maternal seroiogic markers of hepatitis B via placenta and its transformation in these babies were investigated. METHODS: Mothers with positive HBsAg were selected in the third trimester of pregnancy. Their babies received immunoprophylaxis with hepatitis B immunoglobulin and hepatitis B vaccine after birth, and were consecutively followed up for hepatitis B seroiogic markers and HBV DNA at birth, mo 1, 4, 7, 12, and 24. RESULTS: Forty-two babies entered the study, including 16 born to hepatitis B e antigen (HBeAg)-positive HBsAg carrier mothers and 26 to HBeAg-negative HBsAg carrier mothers. Apart from four babies born to HBeAg-positive carrier mothers and demonstrated persistent positive HBeAg eventually became HBV carriers, all other babies developed anti-HBs before 12 mo of age. Among the other 12 babies born to HBeAg-positive carrier mothers, HBeAg was detected in 7 at birth, in 4 at mo 1, and in none of them thereafter. No antibody response to the transplacental HBeAg was detected. Among the babies born to HBeAg-negative carrier mothers, anti-HBe was detected 100% at birth and mo 1, in 88.5% at mo 4, in 46.2% at mo 7, in 4.2% at mo 12 and none in mo 24. Among all the immunoprophylaxis-protected babies born to either HBeAg-positive or HBeAg-negative carrier mothers, anti-HBc was detected in 100% at birth, mo 1 and mo 4, in 78.9% at mo 7, in 36.1% at mo 12 and in none at mo 24. CONCLUSION: HBeAg can pass through human placenta from mother to fetus and become undetectable before 4 mo of age, but no antibodies response to the transplacental HBeAg can be detected till mo 24 in the immunoprophylaxis-protected babies. The sole existence of anti-HBe before 1 year of age or anti-HBc before 2 years of age in babies born to HBsAg carrier mothers may simply represent the transplacental maternal antibodies, instead of indicators of HBV infection status.

Hepatitis B surface antigen clearance in inactive hepatitis B surface antigen carriers treated with peginterferon alfa-2a

AIM: To examine the association between interferon(IFN) therapy and loss of hepatitis B surface antigen(HBs Ag) in inactive HBs Ag carriers. METHODS: This was a retrospective cohort study in inactive HBs Ag carriers, who were treatment-naive, with a serum HBs Ag level < 100 IU/m L and an undetectable hepatitis B virus(HBV) DNA level(< 100 IU/m L). All the 20 treated patients received subcutaneous PEG-IFN alfa-2a 180 μg/wk for 72 wk and were then followed for 24 wk. There were 40 untreated controls matched with 96 wk of observation. Serum HBs Ag, HBV DNA, and alanine aminotransferases were monitored every 3 mo in the treatment group and every 3-6 mo in the control group. RESULTS: Thirteen(65.0%) of 20 treated patients achieved HBs Ag loss, 12 of whom achieved HBs Ag seroconversion. Mean HBs Ag level in treated patients decreased to 6.69 ± 13.04 IU/m L after 24 wk of treatment from a baseline level of 26.22 ± 33.00 IU/m L. Serum HBV DNA level remained undetectable(< 100 IU/m L) in all treated patients during the study. HBs Ag level of the control group decreased from 25.72 ± 25.58 IU/m L at baseline to 17.11 ± 21.62 IU/m L at week 96(P = 0.108). In the control group, no patient experienced HBs Ag loss/seroconversion, and two(5.0%) developed HBV reactivation.CONCLUSION: IFN treatment results in HBs Ag loss and seroconversion in a considerable proportion of inactive HBs Ag carriers with low HBs Ag concentrations.

Hepatitis B surface antigen levels during natural history of chronic hepatitis B: A Chinese perspective study

AIM: To determine the baseline hepatitis B surface antigen (HBsAg) levels during the different phases of chronic hepatitis B (CHB) patients in China.

Inhibition of hepatitis B virus surface antigen expression by small hairpin RNA in vitro

AIM: To explore the anti-hepatitis B virus effect of RNA interference (RNAi) using small hairpin RNA (shRNA)expression vector.METHODS: Hepatitis B virus surface antigen green fluorescent protein (HBs-GFP) fusion vector and shRNA expression vectors were constructed and cotransfected transiently into HepG2 cells. mRNAs extracted from HepG2 cells were detected by real-time PCR. Fluorescence of HBs-GFP protein was detected by fluorescence-activated cell sorting (FACS). The effective shRNA expression vector was transfected into HepG2.2.15 cells. HBsAg and HBeAg in HepG2.2.15 cells were analyzed by radioimmunoassay (RIA) method.RESULTS: FACS revealed that shRNA targeting at HBsAg reduced the GFP signal by 56% compared to the control.Real-time PCR showed that HBs-GFP mRNA extracted from HepG2 cells cotransfected with pAVU6+27 and HBs-GFP expression plasmids decreased by 90% compared to the empty vector control. The expressions of HBsAg and HBeAg were also inhibited by 43% and 64%, respectively.CONCLUSION: RNAi using shRNA expression vector can inhibit the expression of HBsAg, providing a fresh approach to screening the efficient small interfering RNAs (siRNAs).

Serum hepatitis B surface antigen levels predict treatment response to nucleos(t)ide analogues

Quantification of hepatitis B surface antigen(HBsAg)has been suggested to be helpful in the management of chronic hepatitis B(CHB)patients.Nucleos(t)ide analogs(NAs)are the therapy of choice for CHB and are used in the majority of CHB patients.NAs are able to induce hepatitis B virus(HBV)viral suppression,normalization of alanine aminotransferase(ALT)levels,and improvement in liver histology.Automated quantitative assays for serum HBsAg have recently become available,facilitating standardized quantification of serum HBsAg.This has led to increased interest in the clinical application of quantitative serum HBsAg for predicting therapeutic response to NAs.Recent studies have shown that a decline in serum HBsAg levels in patients receiving peginterferon may signal successful induction of immune control over HBV,and can therefore be used to predict therapeutic response.NA treatment typically induces a less rapid decline in HBsAg than interferon treatment;it has been estimated that full HBsAg clearance can require decades of NA treatment.However,a rapid HBsAg decline during NA therapy may identify patients who will show clearance of HBsAg.Currently,there is no consensus on the clinical utility of serum HBsAg monitoring for evaluating patient responses to NA therapy.This review focuses on recent findings regarding the potential application of HBsAg quantification in the management of CHB patients receiving NA therapy.

Liver grafts from hepatitis B surface antigen-positive donors: A review of the literature

The scarcity of available organs and the gap between supply and demand continue to be the main limitations of liver transplantation. To relieve the organ shortage, current transplant strategies have implemented extended criteria, which include the use of liver from patients with signs of past or present hepatitis B virus(HBV) infection. While the use of liver grafts from donors with evidence of past HBV infection is quite limited, some data have been collected regarding the feasibility of transplanting a liver graft from a hepatitis B surface antigen(HBs Ag) positive donor. The aim of the present work was to review the literature regarding liver transplants from HBs Ag-positive donors. A total of 17 studies were identified by a search in Medline. To date, HBs Ag positive grafts have preferentially been allocated to HBs Ag positive recipients. The large majority of these patients continue to be HBs Ag positive despite the use of immunoglobulin, and infection prevention can only be guaranteed by using antiviral prophylaxis. Although serological persistence is evident, no significant HBV-related disease has been observed, except in patients coinfected with delta virus. Consistently less data are available for HBs Ag negative recipients, although they are mostly promising. HBs Agpositive grafts could be an additional organ source for liver transplantation, provided that the risk of reinfection/reactivation is properly prevented.

Screening and evaluation of human single-chain fragment variable antibody against hepatitis B virus surface antigen

BACKGROUND: Phage display technology has become a vital tool in studies aimed at identifying molecules binding to a specific target. It enables the rapid generation and selection of high affinity, fully human antibody product candidates to essentially any disease target appropriate for antibody therapy. In this study, we prepared the recombinant single-chain fragment variable ( ScFv) antibody to hepatitis B virus surface antigen (HBsAg) by the phage display technology for obtaining a virus-targeting mediator. METHODS: mRNA was isolated from B-lymphocytes from a healthy volunteer and converted into cDNA. The fragment variables of heavy and light chain were amplified separately and assembled into ScFv DNA with a specially constructed DNA linker by polymerase chain reaction. The ScFv DNA was ligated into the phagmid vector pCANT-AB5E and the ligated sample was transformed into competent E. coli TG1. The transformed cells were infected with M13K07 helper phage to form a human recombinant phage antibody library. The volume and recombinant rate of the library were evaluated by bacterial colony count and restriction analysis. After two rounds of panning with HBsAg. the phage clones displaying ScFv of the antibody were selected by enzyme-linked immunosorbant assay ( ELISA) from the enriched phage clones. The antigen binding affinity of the positive clone was detected by competition ELISA. HB2151 E. coli was transfected with the positive phage clone demonstrated by competition ELISA for production of a soluble form of the anti-HBsAg ScFv. ELISA assay was used to detect the antigen binding affinity of the soluble anti-HBsAg ScFv. Finally, the relative molecular mass of soluble anti-HBsAg ScFv was measured by SDS-PAGE. RESULTS: The variable heavy ( VH ) and variable light (VL) and ScFv DNAs were about 340bp, 320bp and 750bp, respectively. The volume of the library was up to 2 × 106 and 8 of 10 random clones were recombinants. Two phage clones could strongly compete with the original HBsAb for binding to HBsAg. Within 2 strong positive phage clones, the soluble anti-HBsAg ScFv from one clone was found to have the binding activity with HBsAg. SDS-PAGE showed that the relative molecular weight of soluble anti-HBsAg ScFv was 32 kDa. CONCLUSION: The anti-HBsAg ScFv successfully produced by phage antibody technology may be useful for broadening the scope of application of the antibody.

Long term follow-up and outcome of liver transplantation from hepatitis B surface antigen positive donors

Liver transplant for hepatitis B virus(HBV) currently yields excellent outcomes: it allows to rescue patients with an HBV-related advanced liver disease, resulting in a demographical modification of the waiting list for liver transplant. In an age of patient-tailored treatments, in liver transplantation as well the aim is to offer the best suitable graft to the patient who can benefit from it, also expanding the criteria for organ acceptance and allocation. With the intent of developing strategies to increase the donor pool, we set-up a multicenter study involving 3 Liver Transplant Centers in Italy: patients undergoing liver transplantation between March 03, 2004, and May 21, 2010, were retrospectively evaluated. 1408 patients underwent liver transplantation during the study period, 28(2%) received the graft from hepatitis B surface antigen positive(HBs Ag)-positive deceased donors. The average follow-up after liver transplantation was 63.7 mo [range: 0.1-119.4; SD ± 35.8]. None Primary nonfunction, re-liver transplantation, early or late hepatic artery thrombosis occurred. The 1-, 3-and 5-year graft and patient survival resulted of 85.7%, 82.1%, 78.4%. Our results suggest that the use of HBs Agpositive donors liver grafts is feasible, since HBV can be controlled without affecting graft stability. However, the selection of grafts and the postoperative antiviral therapy should be managed appropriately.

Hepatitis B surface antigen seroconversion after HBV reactivation in non-Hodgkin's lymphoma

Reactivation of hepatitis B virus(HBV)can occur in lymphoma patients infected with HBV when they receive chemotherapy or immunotherapy.Prophylactic administration of lamivudine(LAM)reduces the morbidity and mortality associated with HBV reactivation.However,what defines HBV reactivation and the optimal duration of treatment with LAM have not yet been clearly established.HBV reactivation may occur due to the cessation of prophylactic LAM,although re-treatment with nucleoside analogs may sometimes result in hepatitis B surface antigen(HBsAg)seroconversion,which is a satisfactory endpoint for the management of HBV infection.We report a case of HBV reactivation in a 68-year-old HBsAg-positive patient who received rituximab-based immunochemotherapy for follicular lymphoma.HBV reactivation developed following cessation of prophylactic LAM therapy.The patient subsequently received treatment with entecavir(ETV),which led to a rapid and sustained suppression of HBV replication and HBsAg seroconversion.We also appraised the literature concerning HBV reactivation and the role of ETV in the management of HBV reactivation in lymphoma patients.A total of 28 cases of HBV reactivation have been reported as having been treated with ETV during or after immunosuppressive chemotherapy in lymphoma patients.We conclude that ETV is an efficacious and safe treatment for HBV reactivation following LAM cessation in lymphoma patients treated with rituximab-based immunochemotherapy.

Seroprevalence of hepatitis B surface antigen in pregnant women attending antenatal clinic in Honiara Solomon Islands,2015

AIMTo determine the seroprevalence of hepatitis B surface antigen (HBsAg) among pregnant women attending antenatal clinic in Honiara, Solomon Islands. METHODSThis descriptive cross-sectional study was carried out in seven area health centers in Honiara. From March to June 2015, identification of eligible pregnant women in each site was conducted using systematic random sampling technique. A total of 243 pregnant women who gave written informed consent were enrolled. Standardized tool was used to record demographics, obstetric history and serology results. HBsAg and hepatitis B e antigen (HBeAg) were tested using point-of-care rapid diagnostic test. All HBsAg positive samples were verified using enzyme-linked immunosorbent assay. RESULTSThe mean age of participants was 26 &plusmn; 6 years. The overall hepatitis HBsAg prevalence was 13.8% with higher rate (22%) reported in women between 30-34 years of age. Majority of HBsAg positive participants were Melanesians (29 out for 33). None of the pregnant women in the 15-19 years and &ge; 40 years tested positive for HBsAg. There was no statistically significant difference in HBsAg prevalence by age, ethnicity, education and residential location. The overall HBeAg seroprevalence was 36.7%. Women between 20-24 years of age had the highest rate of 54.5%. Low level of knowledge about hepatitis B vaccination was reputed. Overall, 54.6% of participants were not aware of their hepatitis B vaccination status and only 65.2% of mothers reported their child had been vaccinated. CONCLUSIONHepatitis B is a disease of public health importance in Solomon Islands and emphasize the need for integrated preventative interventions for its control.

Hepatitis B surface antigen and hepatitis B core-related antigen kinetics after adding pegylated-interferon to nucleos(t)ids analogues in hepatitis B e antigen-negative patients

BACKGROUND Hepatitis B e antigen-negative chronic hepatitis B patients under nucleos(t)ids analogues(NAs)rarely achieve hepatitis B surface antigen(HBsAg)loss.AIM To evaluate if the addition of pegylated interferon(Peg-IFN)could decrease HBsAg and hepatitis B core-related antigen(HBcrAg)levels and increase HBsAg loss rate in patients under NAs therapy.METHODS Prospective,non-randomized,open-label trial evaluating the combination of Peg-IFN 180μg/week plus NAs during forty-eight weeks vs NAs in monotherapy.Hepatitis B e antigen-negative non-cirrhotic chronic hepatitis B patients of a tertiary hospital,under NAs therapy for at least 2 years and with undetectable viral load,were eligible.Patients with hepatitis C virus,hepatitis D virus or human immunodeficiency virus co-infection and liver transplanted patients were excluded.HBsAg and HBcrAg levels(log10 U/mL)were measured at baseline and during ninety-six weeks.HBsAg loss rate was evaluated in both groups.Adverse events were recorded in both groups.The kinetic of HBsAg for each treatment group was evaluated from baseline to weeks 24 and 48 by the slope of the HBsAg decline(log10 IU/mL/week)using a linear regression model.RESULTS Sixty-five patients were enrolled,61%receiving tenofovir and 33%entecavir.Thirty-six(55%)were included in Peg-IFN-NA group and 29(44%)in NA group.After matching by age and treatment duration,baseline HBsAg levels were comparable between groups(3.1 vs 3.2)(P=0.25).HBsAg levels at weeks 24,48 and 96 declined in Peg-IFN-NA group(-0.26,-0.40 and-0.44)and remained stable in NA group(-0.10,-0.10 and-0.10)(P<0.05).The slope of HBsAg decline in Peg-IFN-NA group(-0.02)was higher than in NA group(-0.00)(P=0.015).HBcrAg levels did not change.Eight(22%)patients discontinued Peg-IFN due to adverse events.The HBsAg loss was achieved in 3(8.3%)patients of the Peg-IFN-NA group and 0(0%)of the NA group.CONCLUSION The addition of Peg-IFN to NAs caused a greater and faster decrease of HBsAg levels compared to NA therapy.Side effects of Peg-IFN can limit its use in clinical practice.

Significance of hepatitis B virus surface antigen, hepatitis C virus expression in hepatocellular carcinoma and pericarcinomatous tissues

AIM： To investigate the correlation between hepatitis B virus surface antigen （HBsAg）, hepatitis C virus （HCV） expression in hepatocellular carcinoma （HCC）, the HAI score of the noncancerous region of the liver and the serum Alpha fetoprotein （AFP） level. METHODS： The patterns of HBsAg and HCV in 100 cases of HCC and their surrounding liver tissues were studied on paraffin-embedded sections with immunohistochemistry, the histological status was determined by one pathologist and one surgeon simultaneously using the hepatitis activity index （HAIl score, and AFP was detected by radioimmunity. The study included 100 consecutive patients who underwent curative resection for HCC. Based on HBsAg and HCV expression, the patients were classified into 4 groups： patients positive for HBsAg （HBsAg group）, patients positive for HCV （HCV group）, patients negative for both HCV and HBsAg （NBNC group） and patients positive for both HBsAg and HCV （BC group）. RESULTS： The BC group had significantly higher HAI scores than the other three groups. （BC 〉 HCV 〉 HBsAg 〉 NBNC）. HBV and HCV virus infection was positively correlated with HAI （rs = 0.39, P = 0.00011. The positive rate of AFP （85.7%） and the value of AFP （541.2 ng/mL） in the group with HBV and HCV co-infection were the highest among the four groups. The positive rate （53.3%） of AFP and the value of AFP （ 53.3 ng/mL） in the group with none-infection of HBV and HCV were the lowest. HBV and HCV virus infection was positively correlated with AFP（rs = 0.38, P = 0.0001）. CONCLUSION： The AFP increase in patients with liver cancer was positively correlated with the infection of HBV and HCV. The-serum AFP elevation by the infection of HBV and HCV is one of mechanisms which lead to hepatocarcinogenesis, and the antivirus intervening treatment of hepatitis is significant for the prognosis of liver cancer. From our Spearman＇s rank correlation analysis, we can conclude that the severity of virally induced inflammation is correlated with HBsAg and HCV expression in HCC tissues and noncancerous tissues. Prior co-infection of HBV in HCV patients may be an adverse risk factor for intrahepatic inflammation.

High affinity mouse-human chimeric Fab against Hepatitis B surface antigen

AIM： Passive immunotherapy using antibody against hepatitis B surface antigen （HBsAg） has been advocated in certain cases of Hepatitis B infection. We had earlier reported on the cloning and expression of a high affinity scFv derived from a mouse monoclonal （5S） against HBsAg. However this mouse antibody cannot be used for therapeutic purposes as it may elicit anti-mouse immune responses. Chimerization by replacing mouse constant domains with human ones can reduce the immunogenicity of this antibody.METHODS： We cloned the VH and V, genes of this mouse antibody, and fused them with CH1 domain of human IgG1 and C, domain of human kappa chain respectively. These chimeric genes were cloned into a phagemid vector. After initial screening using the phage display system, the chimeric Fab was expressed in soluble form in E. coli.RESULTS： The chimeric Fab was purified from the bacterial periplasmic extract. We characterized the chimeric Fab using several in vitro techniques and it was observed that the chimeric molecule retained the high affinity and specificity of the original mouse monoclonal. This chimeric antibody fragment was further expressed in different strains of E. coli to increase the yield.CONCLUSION： We have generated a mouse-human chimeric Fab against HBsAg without any significant loss in binding and epitope specificity. This chimeric Fab fragment can be further modified to generate a fulllength chimeric antibody for therapeutic uses.

Translational Enhancer of Tobacco mosaic virus Enhancing Expression of Hepatitis B Surface Antigen in Transgenic Panax ginseng C. A. Meyer Callus

The 5＇-nontranslated leader（omega sequence） of Tobacco mosaic virus（TMV） was used as a translational enhancer sequence in the expression of the hepatitis B surface antigen（HBsAg） gene in transgenic ginseng callus cultures. The adr subtype HBsAg gene was placed under the control of the Cauliflower mosaic virus（CaMV） 35S promoter linking to the TMV leader sequence. The antisense omega sequence was used in a control construct. The resulting constructs cloned in the binary vector pBI121 were used to transform the ginseng callus tissue via the Agrobacterium-mediated procedure. The integration and expression of the HBsAg gene were evaluated by PCR and western blot, respectively. Enzyme-linked immunoassays（ELISA） using a monoclonal antibody directed against human serum-derived HBsAg revealed a three to four-fold enhanced expression of HBsAg in ginseng cells conferred by the TMV omega element.

Soluble programmed death-1 is predictive of hepatitis B surface antigen loss in chronic hepatitis B patients after antiviral treatment

BACKGROUND Hepatitis B surface antigen(HBsAg)loss,a functional cure in patients with chronic hepatitis B(CHB)undergoing antiviral therapy,might be an ideal endpoint of antiviral treatment in clinical practice.The factors that contribute to the functional cure remain unclear,and the predictors of functional cure are worth exploring.The concentration and kinetics of soluble programmed death-1(sPD-1)in patients with CHB may play an important role in elucidating the immune response associated with functional cure after nucleos(t)ide analogs therapy.AIM To investigate the factors associated with HBsAg loss and explore the influence of sPD-1 Levels.METHODS This study analyzed the data and samples from patients with CHB who underwent antiviral treatment in a non-interventional observational study conducted at Peking University First Hospital in Beijing(between 2007 and 2019).All patients were followed up:Serum samples were collected every 3 mo during the first year of antiviral treatment and every 6 mo thereafter.Patients with positive hepatitis B e antigen levels at baseline and with available sequential samples who achieved HBsAg loss during antiviral treatment served as the case group.This case group(n=11)was further matched to 44 positive hepatitis B e anti patients without HBsAg loss as controls.The Spearman’s rank correlation test and receiver operating characteristic curves analysis were performed.RESULTS The sPD-1 Levels were higher in patients with HBsAg loss than in those without HBsAg loss from baseline to month 96,and the differences were significant between the groups at baseline(P=0.0136),months 6(P=0.0003),12(P<0.0001),24(P=0.0007),48(P<0.0001),and 96(P=0.0142).After 6 mo of antiviral treatment,the sPD-1 levels were positively correlated with alanine transaminase(ALT)levels(r=0.5103,P=0.0017),and the sPD-1 levels showed apparent correlation with ALT(r=0.6883,P=0.0192)and HBV DNA(r=0.5601,P=0.0703)levels in patients with HBsAg loss.After 12 mo of antiviral treatment,the sPD-1 levels also showed apparent correlation with ALT(r=0.8134,P=0.0042)and HBV DNA(r=0.6832,P=0.0205)levels in patients with HBsAg loss.The sPD-1 levels were negatively correlated with HBsAg levels in all patients after 12 mo of antiviral treatment,especially at 24(r=-0.356,P=0.0497)and 48(r=-0.4783,P=0.0037)mo.After 6 mo of antiviral treatment,the AUC of sPD-1 for HBsAg loss was 0.898(P=0.000),whereas that of HBsAg was 0.617(P=0.419).The cut-off value of sPD-1 was set at 2.34 log pg/mL;the sensitivity and specificity were 100%and 66.7%,respectively.CONCLUSION The sPD-1 levels at 6 mo can predict HBsAg loss after 144 mo of antiviral treatment.

Correlation of hepatitis B surface antigen expression with clinicopathological and biochemical parameters in liver biopsies: A comprehensive study

BACKGROUND Chronic viral B hepatitis(CHB)is a potentially life-threatening liver disease that may progress to liver failure and cirrhosis.Currently,although combinations of different laboratory methods are used in the follow-up and treatment of CHB,the failure of these procedures in some cases has led to the necessity of developing new approaches.In CHB,the intrahepatic expression pattern of viral antigens,including hepatitis B surface antigen(HBsAg),is related to different phases of inflammation.However,many studies have focused on the intracytoplasmic properties of HBsAg staining,and HBsAg positivity in liver tissue has not been evaluated by objective quantitative methods.AIM To investigate the relationship of image analysis-based quantitative HBsAg expression and its staining patterns with clinicopathological factors and treatment in CHB.METHODS A total of 140 liver biopsies from treatment-naïve cases with CHB infection were included in this study.Following diagnosis,all patients were treated with entecavir(0.5 mg)and followed up at three-month intervals.The percentage of immunohistochemical HBsAg(p-HBsAg)expression in the liver was determined in whole tissue sections of biopsies from each case by image analysis.The immunohistochemical staining pattern was also evaluated separately according to 3 different previously defined classifications.RESULTS A positive correlation between p-HBsAg and serum levels of hepatitis B virus(HBV)DNA and HBsAg was observed(P<0.001).The p-HBsAg value was significantly higher in younger patients than in older patients.When the groups were categorized according to the hepatitis B e antigen(HBeAg)status in HBeAgpositive cases,p-HBsAg was correlated with HBV DNA,hepatitis activity index(HAI)and fibrosis scores(P<0.001).In this group,p-HBsAg and HBsAg expression patterns were also correlated with the viral response(VR)and the serological response(SR)(P<0.001).Multivariate analysis revealed that p-HBsAg was an independent predictor of either VR or SR(P<0.001).In HBeAg-negative patients,although HBsAg expression patterns were correlated with both HAI and fibrosis,no relationship was observed among p-HBsAg,clinicopathological factors and VR.CONCLUSION In pretreatment liver biopsies,the immunohistochemical determination of HBsAg expression by quantitative methods,beyond its distribution within the cell,may be a good predictor of the treatment response,especially in HBeAg-positive cases.

The Expression of Sperm Membrane Peptide-Hepatitis B SurfaceAntigen Fusion Protein with Recombinant Vaccinia Virus

A synthetic oligonucleotide, HSD-2a, encoding a peptide segment of the extracel-lular domain of a human sperm membrane protein, YWK-II, was fused with hepatitisB surface antigen gene (HBs gene ). The fused gene was then cloned to pUC18plasmid. The fused gene was prepared from the recombinant pUC18 plasmid byBamH I and Eco R I digestion, and then cloned into the transfer vector pGJP- 5 underthe control of P;., promoter, designated as pGJP-HSD/HBs. CV-1 cells were co-transfected with vaccinia virus (Tian Tan strain) and pGJP-HSD/IIBs and homolo-gous re combination occurred between the vaccinia virus TK gene of the plasmid flank-ing the foreign gene and the same sequences within the virus genome. TK phen0tyPerecombinant virus, vv-HSD/HBs, were selected from trandected HuTK' cells byplaque purthcation technique. The eopressi0n of HSD-b in spent medium and cellu-lar protein of HuTK cells infected with vv-HSD/HBs was determined by ELISAand Western-blot analysis using anti-rwK-II antiserum. The present study indicatesthat the vv-HSD/HBs seems promising as an antdertility vaccine.