Recurrence and influencing factors of hepatitis B surface antigen seroclearance induced by peginterferon alpha-based regimens

BACKGROUND The long-term stability of hepatitis B surface antigen(HBsAg)seroclearance following peginterferon alpha(peg-IFN-α)-based therapy has not been extensively studied,leaving the full potential and limitations of this strategy unclear.AIM To assess HBsAg recurrence after seroclearance achieved by peg-IFN-αregimens.METHODS This prospective,multicenter,observational study was conducted from November 2015 to June 2021 at three Chinese hospitals:The Second Affiliated Hospital of Xi’an Jiaotong University,Ankang Central Hospital,and The Affiliated Hospital of Yan’an University.Participants who achieved HBsAg seroclearance following peg-IFN-α-based treatments were monitored every 4-12 weeks post-treatment for hepatitis B virus(HBV)markers,HBV DNA,and liver function.The primary outcome was HBV recurrence,defined as the reemergence of HBsAg,HBV DNA,or both,at least twice within 4-8 weeks of follow-up.RESULTS In total,121 patients who achieved HBsAg seroclearance were enrolled.After a median follow-up of 84.0(48.0,132.0)weeks,four subjects were lost to follow-up.HBsAg recurrence was detected in 16 patients.The cumulative HBsAg recurrence rate in the intention-to-treat population was 15.2%.Multivariate logistic regression analysis demonstrated that consolidation time<12 weeks[odds ratio(OR)=28.044,95%CI:4.525-173.791]and hepatitis B surface antibody disappearance during follow-up(OR=46.445,95%CI:2.571-838.957)were strong predictors of HBsAg recurrence.HBV DNA positivity and decompensation of liver cirrhosis and hepatocellular carcinoma were not observed.CONCLUSION HBsAg seroclearance following peg-IFN-αtreatment was durable over 84 weeks of follow-up with a cumulative recurrence rate of 15.2%.

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.

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.

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.

Clinical utility of hepatitis B surface antigen kinetics in treatment-na?ve chronic hepatitis B patients during longterm entecavir therapy

AIM To investigate the utility of hepatitis B surface antigen(HBsAg) kinetics in chronic hepatitis B patients during long-term entecavir treatment.METHODS This retrospective study included treatment-na?ve chronic hepatitis B patients who received at least 2 years of consecutive entecavir treatment. Patients were followed up at three to six month intervals with liver biochemistry, hepatitis B virus DNA, and abdominal sonography. In hepatitis B e antigen(HBeAg)-positive patients, HBeAg levels were assessed every three to six month until results became negative. Serum HBsAg levels were determined at the baseline, oneyear and five-year time points. Liver cirrhosis was diagnosed through liver biopsy, imaging examinations, or clinical findings of portal hypertension. Hepatocellular carcinoma was diagnosed by histological examination or dynamic image studies.RESULTS A total of 211 patients were enrolled. The median treatment time was 5.24(2.00-9.62) years. Multivariate analysis showed that lower baseline HBsAg levels were associated with an earlier virological response, earlier hepatitis B e antigen(HBeAg) seroconversion, and earlier biochemical response in HBeAg-positive patients(cut-off value: 4 log IU/mL) and an earlier virological response in HBeAg-negative non-cirrhotic patients(cut-off value: 2.4 log IU/mL). Although HBsAg levels decreased slowly during long-term entecavir treatment, higher HBsAg decrease rates were found in the first year for HBeAg-positive non-cirrhotic patients, and patients with higher baseline HBsAg levels. More favorable clinical outcomes were not observed by a rapid HBsAg decline per se, but depended on lower baseline HBsAg levels.CONCLUSION Baseline HBsAg can be used to predict treatment responses. HBsAg levels and decrease rates should be considered together according to disease status while interpreting HBsAg changes.

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.

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.

Evaluation of changes of serum hepatitis B surface antigen from a different perspective

AIM:To investigate the dynamic changes of serum hepatitis B surface antigen(HBs Ag) levels apportioned by the same hepatic parenchyma cell volume(HPCV),namely,hepatic cell quantities.METHODS:Serum HBs Ag levels were detected by electrochemiluminescence and serum HBs Ag levels apportioned by the same HPCV were figured out according to the theory of sphere geometry.HBs Ag levels were compared among different liver inflammation grades,as well as different hepatic fibrosis stages.RESULTS:In hepatitis B e antigen-negative chronic hepatitis B,serum HBs Ag levels in liver histological inflammation grades 1-4 were 3.66 ± 0.40,3.74 ± 0.35,3.74 ± 0.26 and 3.71 ± 0.34 log10 COI(cut off index),respectively,and there were no differences before apportion(P =0.640).Serum HBs Ag levels apportioned by the same HPCV were 5.57 ± 0.62,5.98 ± 0.65,6.59 ± 0.50 and 6.81 ± 0.84 log10 COI,respectively,and there were significant differences after apportion(P < 0.001).Serum HBs Ag levels in hepatic fibrosis stagesⅠ-Ⅳ were 3.66 ± 0.43,3.75 ± 0.33,3.71 ± 0.28 and 3.75 ± 0.26 log10 COI,respectively,and there were no differences before apportion(P =0.513).Serum HBs Ag levels apportioned by the same HPCV were 5.53 ± 0.66,5.98 ± 0.53,6.29 ± 0.46 and 7.06 ± 0.48 log10 COI,respectively,and there were significant differences after apportion(P < 0.001).CONCLUSION:Serum HBs Ag levels apportioned by the same HPCV(hepatic cell quantities),rather than serum HBs Ag levels,increase with liver inflammation grades and hepatic fibrosis stages.

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).

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.

Hepatitis B surface antigen levels of cessation of nucleos(t)ide analogs associated with virological relapse in hepatitis B surface antigen-negative chronic hepatitis B patients

AIM:To investigate the virological relapse rate in hepatitis B e antigen(HBeAg)-negative patients after antiviral therapy discontinuation and analyze the factors associated with virological relapse.METHODS:Among patients diagnosed with chronic hepatitis B infection between May 2005 and July2010,204 were eligible for analysis.The Kaplan-Meier method and log-rank test were used to calculate the cumulative rate of relapse and compare cumulative relapse rates between groups.The Cox proportional hazards regression model was used to evaluate the predictive factor of virological relapse.RESULTS:The 2 and 1 year cumulative risks of virological relapse after antiviral therapy discontinuation were 79.41%(162/204) and 43.82%(71/162),respectively.Multivariate analysis revealed that only post treatment hepatitis B surface antigen(HBsAg)level was associated with virological relapse {P= 0.011).The cumulative risk of virological relapse was higher in the patients with HBsAg levels ≥1500 IU/L than in those with HBsAg levels < 1500 IU/L(P= 0.0013).The area under the curve was 0.603(P= 0.033).The cutoff HBsAg value for predicting virological relapse was 1443IU/L CONCLUSION:We found that the virological relapse rate remained high after antiviral therapy discontinuation in the HBeAg-negative patients and that the post treatment HBsAg levels predicted virological relapse.

Hepatitis B surface antigen escape mutations: Indications for initiation of antiviral therapy revisited

Approximately 240 million people are chronically infected with hepatitis B. The implementation of rigorous vaccination programs has led to an overall decrease in the prevalence of this disease worldwide but this may also have led to emergence of viral mutations that can escape the protection of hepatitis B surface antibody. As this phenomenon is increasingly recognized, concern for transmission to vaccinated individuals has also been raised. Herein, we describe two cases where the suspected presence of a hepatitis B surface antigen escape mutation impacted the decision to initiate early antiviral therapy, as well as provide a brief review of these mutations. Our findings described here suggest that a lower threshold for initiating therapy in these individuals should be considered in order to reduce the risk of transmission, as vaccination does not provide protection.

Expression of hepatitis B virus surface antigen in 120 Hodgkin's lymphoma patients

Background and Objective: Little is known about the incidence of hepatitis B virus (HBV) infection in Hodgkin's lymphoma patients. This study was to evaluate the impact of HBV infection on the survival of Hodgkin's lymphoma patient. Methods: Clinical data of 120 Hodgkin's lymphoma patients treated at the Sun Yat-sen University Cancer Center between January 2004 and October 2007 were collected. The impact of prognostic factors including HBV infection on survival was examined by univariate and multivariate analyses. A log-rank test was used for univariate analysis and the Cox proportional hazards regression model was used for multivariate analysis. Results: Of the 120 patients, 18 (15.0%) were hepatitis B virus surface antigen (HBsAg)-positive. The HBsAg-positive patients had lower 5-year survival rate than did the HBsAg-negative ones (66.9% vs. 91.3%, P = 0.006). When the patients were divided into early-stage (Ⅰ+Ⅱ) and advanced-stage (Ⅲ+Ⅳ) groups, the 5-year survival rate was significantly different between the HBsAg-positive and -negative patients in early-stage group (64.8% vs. 96.0%, P < 0.001), while not significantly different in advanced-stage group (75.0% vs. 84.8%, P=0.667). Both univariate and multivariate analyses showed that radiotherapy and HBV infection were independent prognosis factors for the patients with early-stage Hodgkin's lymphoma (P=0.006 and 0.014, respectively). Conclusions: The incidence of HBV infection is similar between Hodgkin's lymphoma patients and normal population. HBV infection is an independent prognosis factor for survival in the patients with early-stage Hodgkin's lymphoma.

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.

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.

Expression of hepatitis B virus surface antigens induces defective gonad phenotypes in Caenorhabditis elegans

AIM To test whether a simple animal, Caenorhabditis elegans(C. elegans), can be used as an alternative model to study the interaction between hepatitis B virus antigens(HBs Ag) and host factors. METHODS Three plasmids that were able to express the large, middle and small forms of HBs Ags(LHBs Ag, MHBs Ag, and SHBs Ag, respectively) driven by a ubiquitous promoter(fib-1) and three that were able to express SHBs Ag driven by different tissue-specific promoters were constructed and microinjected into worms. The brood size, egglaying rate, and gonad development of transgenic worms were analyzed using microscopy. Levels of m RNA related to endoplasmic reticulum stress, enpl-1, hsp-4, pdi-3 and xbp-1, were determined using reverse transcription polymerase reaction(RT-PCRs) in three lines of transgenic worms and dithiothreitol(DTT)-treated wild-type worms. RESULTS Severe defects in egg-laying, decreases in brood size, and gonad retardation were observed in transgenic worms expressing SHBs Ag whereas moderate defects were observed in transgenic worms expressing LHBs Ag and MHBs Ag. RT-PCR analysis revealed that enpl-1, hsp-4 and pdi-3 transcripts were significantly elevated in worms expressing LHBs Ag and MHBs Ag and in wild-type worms pretreated with DTT. By contrast, only pdi-3 was increased in worms expressing SHBs Ag. To further determine which tissue expressing SHBs Ag could induce gonad retardation, we substituted the fib-1 promoter with three tissue-specific promoters(myo-2 for the pharynx, est-1 for the intestines and mec-7 for the neurons) and generated corresponding transgenic animals. Moderate defective phenotypes were observed in worms expressing SHBs Ag in the pharynx and intestines but not in worms expressing SHBs Ag in the neurons, suggesting that the secreted SHBs Ag may trigger a cross-talk signal between the digestive track and the gonad resulting in defective phenotypes. CONCLUSION Ectopic expression of three forms of HBs Ag that causes recognizable phenotypes in transgenic worms suggests that C. elegans can be used as an alternative model for studying virus-host interactions because the resulting phenotype is easily detected through microscopy.

Predictors of loss of hepatitis B surface antigen in HIV-infected patients

AIM:To study factors associated with loss of hepatitis B surface antigen (HBsAg) in patients co-infected with human immunodeficiency virus (HIV) and hepatitis B virus (HBV).METHODS:We retrospectively reviewed the medical records of 5681 patients followed up at two New York City HIV clinics from January 1999 to May 2007.Clinical and laboratory parameters including baseline and follow-up HIV viral loads,CD4 cell counts,alanine transaminase levels,demographics,presence of hepatitis C infection,and treatment with highly active antiretroviral therapy dually active against both HIV and HBV infection,were analyzed to determine factors associated with loss of HBsAg.RESULTS:Three hundred and fifty five patients (355/5681,6.84%) were co-infected with HIV and HBV and were evaluated.Of these,226 patients with more than 12 mo follow-up were included in further analysis to determine factors associated with loss of HBsAg in the long-term follow-up.In the univariate analysis,baseline CD4 cell count was associated with loss of HBsAg (P=0.052).Cox regression analysis revealed that loss of HBsAg was associated with baseline CD4 cell count > 500 cells/mm3 (P=0.016,odds ratio:76.174,95% confidence interval:2.233-2598.481).CONCLUSION:Our study showed an interesting association of loss of HBsAg in HIV-HBV co-infected patients with higher CD4 cell count,suggesting that T-cell cytolytic activity against HBV may still be effective in clearing HBV infection.

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.

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.