待孕夫妇乙肝表面抗原及乙肝表面抗体阳性情况分析

目的 分析与探讨待孕夫妇乙肝表面抗原及乙肝表面抗体检测结果,并研究其对临床孕前检查的影响及评价。方法 随机选取2015‒2017年度在我院进行孕前检查的夫妇2440对（4 880例）为研究对象,按照年度将待孕夫妇分为两组,每组2 440例,两组均加强孕前检查中的乙肝表面抗原（HBsAg）及乙肝表面抗体（HBsAb）的检测。A组为2015年3月‒2016年2月在我院进行乙肝表面抗原及乙肝表面抗体检查的待孕夫妇;B组为2016年3月‒2017年2月在我院进行乙肝表面抗原及乙肝表面抗体检查的待孕夫妇。比较两组待孕夫妇乙肝表面抗原及乙肝表面抗体检测的阳性结果。结果 B组HBsAg阳性率、HBsAb阳性率明显高于A组（6.43% vs 4.63%;62.99% vs 58.44%）,差异有统计学意义（P＜0.05）。B组、A组男性HBsAg阳性率明显高于同组女性（59.87% vs 40.13%;60.18% vs 39.82%）,HBsAb阳性率低于同组女性（46.52% vs 53.48%;47.41% vs 52.59%）,差异均有统计学意义（P＜0.05）。B组、A组高中及以上学历HBsAg阳性率明显低于同组高中以下学历（38.85% vs 61.95%;38.05% vs 61.15%）,高中及以上学历HBsAb阳性率高于同组高中以下学历（53.15% vs 46.84%;51.75% vs 48.25%）,差异均有统计学意义（P＜0.05）结论 目前夫妇乙肝感染仍处于增高趋势,对于进行孕前检查的待孕夫妇加强乙肝表面抗原及乙肝表面抗体的检测,有助于疾病的早期诊断、干预及治疗,能够减少乙肝传播,可有效降低新生儿乙肝发病率,促进优生优育,提高出生人口整体素质。     

IgE antibody against hepatitis B surface antigen in mice

Hepatitis B surface antigen (HBs antigen) was examined for elicitation of IgE production by injection into mice. The Prausnitz-Küstner (PK)-type skin test in the rat was employed for detection of IgE antibody to HBs antigen, because no sufficient purified HBs antigen was available as the challenging antigen for the passive cutaneous anaphylaxis (PCA) test in rats. The positive PK test was considered to be due to IgE antibody, since the active principle was inactivated by heating the sera at 56 C for 30 min, did not bind to protein A and was eliminated by anti-mouse IgE antisera. These data indicate that the PK-type test in rats can be used for detection of mouse IgE antibody when the amount of a test sample is not sufficient for the PCA test in rats.     

Standardization and validation of an alkaline phosphatase-linked immunoassay to quantify a plant-derived antibody directed against the hepatitis B virus surface antigen

Immunopurification is one of the most effective chromatography steps to purify the hepatitis B surface antigen, which have successfully been used as an active pharmaceutical ingredient of hepatitis B vaccines. Plant-derived antibodies could be an appropriated ligand for such purposes because plants are the most cost-effective production systems and have the additional advantage that plant viruses cannot infect humans. In this work, a polyclonal antibody alkaline phosphatase-linked immunoassay was standardized and validated to quantify a plant-derived antibody directed against the HBsAg. The validation of an immunoassay to quantify plantibodies is a relatively complex task due to the complexity of the plant extract, the low level of expression of this molecule, and the potential interferences of endogenous peroxidases contributed by plants. These results allow estimating the plant-derived antibody concentration up to 3.81 ng/mL with high specificity, precision, and repeatability. The working range of the standard curve was between 3.81 and 60 ng/mL, and the intra- and inter-variation coefficients were between 10% and 20% in a production process's sample dependent way. This enzyme-linked immunosorbent assay is considered valuable to improve the design of the purification process and also to obtain a better estimation of the antibody expression level and process's recovery.     

Enhanced chemiluminescence ELISA for the detection of antibody to hepatitis B virus surface antigen

A chemiluminescent enzyme linked immunosorbent assay (ELISA) for the detection of antibody to hepatitis B virus surface antigen (anti-HBs) in human serum has been developed. Polystyrene microtitre plates were coated with recombinant, yeast-derived hepatitis B surface antigen (rec-HBsAg). Patient serum samples and appropriate controls were added to the rec-HBsAg-coated wells and incubated to bind anti-HBs. The wells were then washed and a fluorescein isothiocyanate (FITC) conjugate of a human plasma-derived hepatitis B surface antigen (HBsAg) was added. Following incubation and further washing the bound FITC-labelled HBsAg was detected after addition of a horseradish peroxidase (HRP) conjugate of a monoclonal anti-FITC antibody and assaying for the enzyme. The activity of the HRP was measured using luminol and hydrogen peroxide as substrates and iodophenol as a chemiluminescence enhancer. The luminescence was recorded using a camera luminometer. Preliminary tests have shown the assay to be suitable for the detection of antibody in sera from both vaccinees and also from individuals with a past hepatitis B virus infection. The use of the FITC-anti-FITC system together with the measurement of a chemiluminescence signal makes possible the completion of this assay in a few hours. The assay has been shown to be both specific and sensitive and provides a permanent photographic record.     

Production of antibody to individual polypeptides derived from purified hepatitis B surface antigen.

Purified preparations of hepatitis B surface antigen (HBsAg) were solubilized with sodium dodecyl sulfate and urea under reducing conditions and subsequently fractionated by preparative sodium dodecyl sulfate-urea polyacrylamide gel electrophoresis (PAGE). Pools of the individual fractions eluted from the preparative PAGE were concentrated and purified further by analytical PAGE. Five purified polypeptides were isolated from HBsAg, types adw and ayw, with molecular weights of 19,000, 24,000, 27,000, 35,000, and 40,000. Each preparations was emulsified in Freund complete adjuvant and injected into guinea pigs. Antibody to each HBsAg type was measured by radioimmunoassay. The 19,000 molecular weight polypeptide derived from ayw particles and the 27,000 molecular weight subunit obtained from both types failed to elicit an antibody response. The other three polypeptides derived from the ayw particles elicited group-specific antibody responses. Similar group-specific reactivities were observed in the testing of anti-adw 35,000 and anti-adw 40,000 molecular weight polypeptide sera. However, guinea pigs immunized with the 19,000 and the 24,000 molecular weight polypeptides of the adw type produced antibody that reacted preferentially with adw particles. This indicates that either these subunits carry predominately d determinants or that, because of the low levels of material used for inoculation, no immune response or an undetectable one was elicited to the a or w components.     

Human antibody immunosorption of hepatitis B surface antigen from blood and plasma

Removal of the Hepatitis B surface antigen (HBsAg) from whole blood and blood products, using human antibody (HBAb) immunosorbent, was studied and kinetics of complexing were monitored using radioimmunoassay (RIA). An intermittent complexing process was developed that minimizes damage to the cellular components of blood. HBsAg concentration in blood was reduced 1.5 to 2 logarithmic cycles in 3 hr with this system. Free HBsAg remaining in solution at equilibrium was further reduced by transferring the blood to a vessel containing unused immunosorbent. Through multiple stage treatment of a blood sample, it may be possible to reduce the probability of contamination with HBsAg to below the infectious level. This process may be applied to the selective removal of other proteins from blood and plasma.     

Transplacentally acquired maternal antibody against hepatitis B surface antigen in infants and its influence on the response to hepatitis B vaccine

Background

Passively acquired maternal antibodies in infants may inhibit active immune responses to vaccines. Whether maternal antibody against hepatitis B surface antigen (anti-HBs) in infants may influence the long-term immunogenicity of hepatitis B vaccine remains unknown.

Methodology/Principal Findings

Totally 338 pairs of mothers and children were enrolled. All infants were routinely vaccinated against hepatitis B based on 0-, 1- and 6-month schedule. We characterized the transplacental transfer of maternal anti-HBs, and compared anti-HBs response in children of mothers with or without anti-HBs. In a prospective observation, all 63 anti-HBs positive mothers transferred anti-HBs to their infants; 84.1% of the infants had higher anti-HBs concentrations than their mothers. One and half years after vaccination with three doses of hepatitis B vaccine, the positive rate and geometric mean concentration (GMC) of anti-HBs in 32 infants with maternal anti-HBs were comparable with those in 32 infants without maternal antibody (90.6% vs 87.5%, P = 0.688, and 74.5 vs 73.5 mIU/ml, P = 0.742, respectively). In a retrospective analysis, five and half years after vaccination with three doses vaccine, the positive rates of anti-HBs in 88 children of mothers with anti-HBs ≥1000 mIU/ml, 94 children of mothers with anti-HBs 10–999 mIU/ml, and 61 children of mothers with anti-HBs <10 mIU/ml were 72.7%, 69.2%, and 63.9% (P = 0.521), respectively; anti-HBs GMC in these three groups were 38.9, 43.9, and 31.7 mIU/ml (P = 0.726), respectively.

Conclusions/Significance

The data demonstrate that maternal anti-HBs in infants, even at high concentrations, does not inhibit the long-term immunogenicity of hepatitis B vaccine. Thus, current hepatitis B vaccination schedule for infants will be still effective in the future when most infants are positive for maternal anti-HBs due to the massive vaccination against hepatitis B.     

Establishment of hybridoma secreting human monoclonal antibody against hepatitis B virus surface antigen

The HAT (hypoxanthine, aminopterin, thymidine) sensitive and ouabain resistant human B lymphoblastoid cell line TAW-925 was obtained from 6-thioguanine resistant B lymphoblastoid cell line WI-L2. Hybridomas were obtained at a high frequency (10(-4)-10(-5) when TAW-925 was hybridized with cells transformed with Epstein-Barr virus. Using TAW-925 as a parental cell line, we have obtained a hybridoma which stably secretes human monoclonal antibody against hepatitis B virus surface antigen.     

Single-chain antibody fragments specific to the hepatitis B surface antigen, produced in recombinant tobacco cell cultures

An anti-hepatitis B surface antigen (HBsAg), single-chain Fv antibody fragment (scFv) with a 6-histidine N-terminal tag was produced in cultured transgenic tobacco cells. Western blot and antigen-specific chromatography showed high levels of biologically active scFv in the culture supernatant (1 mg l^–1) and in cells (5 mg kg^–1). A simple one-step scFv purification was developed using immobilized metal ion affinity chromatography.     

Patterns of circulating hepatitis B surface antigen variants among vaccinated children born to hepatitis B surface antigen carrier and non-carrier mothers

Hepatitis B virus (HBV) variants that possessed missense mutation within the neutralization epitope of the major S antigen as defined by amino acid residues (aa#) 124–147, termed the a determinant variants, were identified through a population-based serosurvey of 2,305 children of the vaccinated birth cohorts born after 1986. Data on the 678 nucleotides encoding the S antigen of HBV were available for 75 HBV strains that were collected from 63 vaccinated children and 12 unvaccinated or incompletely vaccinated children, and 21 HBV strains from 25 unvaccinated adults. Among the diverse patterns of one to three amino acid substitutions within the a determinant, 145-Arg occurred most frequently (5/14); other variants were: 126-Ala, 127-Thr, 126-Ser/131-Asn/133-Thr, 129-His, 129-Arg, 123-Asn/131-Ile, 133-Leu, 141-Glu, and 141-Arg/144-Ala. Only one of these variants occurred in the 16 hepatitis B surface antigen (HBsAg)-carrier children born to HBsAg-negative mothers, whereas 12 of these variants occurred in the 20 (50%) children born to HBsAg-positive mothers. In addition, early administration of HBV vaccine within the noenatal period increased the likelihood of the emergence of these variants to 64.7% (11/17). Five of the 21 (23.8%) unvaccinated HBsAg-carrier adults harbored the a determinant variants possessing mutations within aa# 125–136, i.e. the putative first loop formed by the cysteine disulfide bonds. Vaccinated children were likely to harbor HBV variants possessing mutations involving altered charge of side chains and/or its hydrophobicity of amino acid residues within the putative second loop between aa#140 and 146. Our data suggest that emergence of these HBV S gene mutants in the phase of HBV vaccination program would be most common among populations in whom perinatal/vertical transmission of HBV is most common, i.e. southeast Asian and the Taiwanese.     

Optimisation of the coupled monoclonal antibody density for recombinant hepatitis B virus surface antigen immunopurification

Using immunosorbents based upon cyanogen bromide-Sepharose CL-4B, we have examined different ligand densities in coupling of monoclonal antibody (MAb) to find the best performance, for recombinant hepatitis B surface antigen (rHBsAg) purification. Three replicates of 5 and 15 cycles of densities ranges: 2.17-2.19, 3.18-3.62, 4.06-4.17, and 5.13-5.40 mg/ml (control); or 1.81-2.47, 3.17-3.41, 4.16-4.28, and 5.16-5.19 mg/ml (control), respectively were evaluated in terms of binding capacity, antigen recovery, ligand leakage and purity of antigen, and compared to the control. Adsorption and antigen recovery of immunosorbents manufactured were not different statistically, eventhough increased 8.08 and 9.90% at a range of 3.17-3.41 mg/ml. At this range, efficiency expressed as productivity and MAb saving was optimal. Ligand leakage and purity of antigen showed similar behaviour among all densities. Aspects related to ligand density in antigen immunoaffinity purification are discussed.     

Proteins of hepatitis B surface antigen.

Purified 22-nm forms of hepatitis B surface antigen (Hbsag) representing the three major antigenic subtypes (adw, ayw, and adr) were analyzed for their constituent polypeptides by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. No consistent difference in either the number or relative distributions of the polypeptides was observed for the various subtypes. Seven polypeptides were designated as P-1 through P-7 in order of their decreasing mobilities. By comparison with protein standards, their molecular weights were estimated as 23, 29.5, 36, 41.5, 53.5, 72, and 97 thousand. The P-1 and P-2 components represented the major polypeptides; P-2 and P-5 might by glycoproteins, based on their reaction with periodic acid-Shiff reagent. Each polypeptide contains cysteine residues. HBSAg was radiolabeled with 3H or 14C by reductive methylation or iodinated with 125I by the chloramine-T or lactoperoxidase procedures. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of labeled HBSAg yielded patterns identical to those obtained with protein stain. Comparison of HBSAg labeled by the chloramine-T and lactoperoxide procedures indicated that there was no distinction between internal or external components within the 22-nm structure.     

Overcoming T cell tolerance to the hepatitis B virus surface antigen in hepatitis B virus-transgenic mice

The sequence of the hepatitis B virus (HBV) major envelope (Env) protein (ayw subtype) was scanned for the presence of H-2(d,b) motifs. Following binding and immunogenicity testing, two new H-2(d)-restricted epitopes (Env.362 and Env.364) were identified. These epitopes induced CTLs capable of recognizing naturally processed HBV-Env, but were apparently generated with lower efficiency than the previously defined dominant Env.28 epitope. Next, HBV-transgenic mice that express all of the HBV proteins and produce fully infectious particles were immunized with a mixture of lipopeptides encompassing the Env.28, Env.362, and Env.364 epitopes. Significant CTL responses were obtained, but they had no effect on viral replication in the liver, nor did they induce an inflammatory liver disease. However, in adoptive transfer experiments, CTL lines generated from the HBV-transgenic mice following immunization were able to inhibit viral replication in vivo without causing hepatitis. This is in contrast to CTL lines derived from nontransgenic mice that displayed both antiviral and cytopathic effects, presumably because they displayed higher avidity for the viral epitopes than the transgenic CTLs. These results suggest that T cell tolerance to HBV can be broken with appropriate immunization but the magnitude and characteristics of the resultant T cell response are significantly different from the response in HBV-naive individuals since their antiviral potential is stronger than their cytotoxic potential. This has obvious implications for immunotherapy of chronic HBV infection.     

Intracellular expression of a cloned antibody fragment interferes with hepatitis B virus surface antigen secretion

We evaluated the potential of an intracellularly expressed antibody fragment to interfere with hepatitis B virus (HBV). Sequences coding for the immunoglobulin variable regions of the HBV surface antigen (HBsAg) specific monoclonal antibody 5C3 were isolated and characterized. A secretory pathway-targeted, 5C3 derived single chain Fv (sFv) fragment was expressed in HuH-7 hepatocellular carcinoma cells together with HBsAg. Quantification of extracellular HBsAg levels in the cell culture supernatant demonstrated that the presence of the 5C3 sFv equipped with a secretory pathway retention signal SEKDEL reduced extracellular HBsAg levels by a mean of 85%. Co-immunoprecipitation studies revealed that the 5C3 sFv targeted to the secretory pathway physically interacted with its target antigen, HBsAg. Confocal microscopy studies confirmed the intracellular expression and colocalization of the 5C3 sFv and HBsAg. We conclude that certain intracellularly expressed antibody fragments will substantially interfere with HBV antigen secretion from the cell.