Specific Antibody Concentrations Research Articles

A novel antibody avidity methodology for rapid point-of-care serological diagnosis

A novel methodology is introduced for rapid serological diagnosis. This methodology combines the antibody bridging assay principle with the measurement of antibody avidity. The combination allows the determination of the infection phase with a single dilution of a single sample of serum. This is a significant improvement on current serological techniques which often require either paired-sample testing (IgG/IgM serology) or testing of the sample in several dilutions (IgG avidity testing). Assay methods were developed on two immunoassay platforms; the heterogeneous time-resolved fluoroimmunoassay and the separation-free two-photon excitation fluorometry. The new methods were compared to conventional class-specific IgG/IgM and IgG avidity techniques. The major findings were that the avidity results of the new methodology were independent of the sample dilution (specific antibody concentration in serum) and consistent between immunoassay platforms. This new methodology is simple, rapid, and quick to perform. It provides the possibility of running serodiagnostic tests at point-of-care with bench-top random-access analyzers.

Measurement of anti-Aβ1–42 antibodies in intravenous immunoglobulin with indirect ELISA: The problem of nonspecific binding

Improvement in cognitive scores in patients with Alzheimer's disease (AD) has been reported in two trials in which intravenous immunoglobulin (IvIg) preparations were administered. IvIg's benefits in AD patients have been suggested to be due to antibodies to amyloid-beta (Aβ). Our previous study using indirect enzyme-linked immunosorbent assay (ELISA) indicated that much of IvIg's apparent binding to Aβ1–42 is nonspecific; it is detectable even when IvIg is incubated on “specificity controls” (bovine serum albumin [BSA] and Aβ reverse sequence Aβ42–1) rather than Aβ1–42. The objective of this study was to evaluate procedures that might reduce this nonspecific binding. The IvIg preparation used was Gamunex (Talecris Biotherapeutics). Multiple blocking agents were evaluated, but even the most effective blocker only reduced nonspecific binding by 48%. Dissociating Gamunex's antibody–antigen complexes had no effect on specific binding when Aβ42–1 was used as the specificity control, although it increased this binding when BSA was the specificity control. Decreasing Gamunex's dilution from 1:1,500 to 1:500 resulted in a slight (7.4%) but significant ( p = 0.027) increase in specific binding. Using a sandwich ELISA to measure Gamunex's anti-Aβ antibodies resulted in even less specific binding to Aβ1–42 than with the indirect ELISA. Despite Gamunex's low percentage of specific binding to Aβ1–42, it inhibited Aβ oligomer formation. We conclude that, when anti-Aβ antibodies in IvIg are measured by indirect ELISA, extensive nonspecific binding occurs despite procedures taken to prevent it. This must be subtracted from total binding to accurately measure specific anti-Aβ antibody concentrations.

New adjuvants for accelerated and enhanced antibody response

Immunization of animals and birds for the purposes of developing hyperimmune sera or purification of specific antibodies heavily relies on adjuvants. PickCell Laboratories offers a new generation of adjuvants that greatly accelerate development of specific response, decrease the required dose of antigen and increase up to 100-fold the concentration of specific antibody in serum.

Comparative study between the protective effects of Saudi and Egyptian antivenoms, alone or in combination with ion channel modulators, against deleterious actions of Leiurus quinquestriatus scorpion venom

This study compared efficacy of two polyvalent antivenoms (Saudi Arabian and Egyptian), against lethality and pathophysiological changes of Leiurus quinquestriatus quinquestriatus ( LQQ) scorpion venom in mice. Additionally, the study examined whether treatment with selected ion channel modulators, lidocaine, nimodipine or amiodarone would be effective, alone or combined with the antivenoms. The protein concentration of the Saudi antivenom was 1/3 of Egyptian, indicating lesser immunogenicity, while both preservative contents were within limits. In immunodiffusion experiments, both exhibited prominent precipitin bands indicating high concentrations of specific antibodies. Neutralizing capacities (60–70 LD 50) stated on labels were confirmed. Both antivenoms significantly ( P < 0.001) prolonged survival time (from 26.9 ± 1.18 min, 100% dead with venom to 224–300 min, 0–30% dead) of envenomed mice, whether injected iv before or 5 min after venom. Injection of either antivenom plus ion channel modulators, gave comparable results to that observed in mice treated with antivenoms alone. The Na + channel blocker lidocaine and the Ca 2+ channel blocker nimodipine on their own significantly protected the animals ( P < 0.05), but to a lesser extent. The two antivenoms, significantly ameliorated the venom-evoked changes in serum LDH ( P < 0.001) and CKMB ( P < 0.01) plus cardiac TNFα and nitrate/nitrite levels ( P < 0.001). When combined with lidocaine or nimodipine, the effects were not greater than antivenom alone. Moreover, the antivenoms ameliorated characteristic venom-evoked changes in the isolated perfused Langendorff hearts. Lidocaine and amiodarone were more effective than nimodipine. In Conclusion both Saudi and Egyptian antivenoms protected mice from the pathological and lethal effects of LQQ scorpion. Sodium and calcium channel blockers, lidocaine and nimodipine, may be useful when antivenoms are not available.

Antibody concentrations to Aβ1–42 monomer and soluble oligomers in untreated and antibody–antigen-dissociated intravenous immunoglobulin preparations

Cognitive improvement in Alzheimer's disease (AD) patients treated with intravenous immunoglobulin (IvIg) has been attributed to its antibodies to amyloid beta (Aβ). We compared the concentrations of specific antibodies to soluble Aβ1–42 conformations, namely Aβ1–42 monomer and Aβ1–42 soluble oligomers, between three IvIg preparations, Gamunex, Gammagard, and Flebogamma. To determine specific antibody concentrations to these Aβ1–42 conformations, nonspecific binding of the IvIg preparations to the Aβ reverse sequence, Aβ42–1, was subtracted. These antibodies were measured in untreated IvIg preparations and also after they were treated to dissociate antibody–antigen complexes, because this procedure has been reported to increase the detectable levels of serum anti-Aβ antibodies. Antibody levels to Aβ1–42 monomer were significantly higher in untreated Gamunex than in the other two IvIg preparations, and antibody–antigen dissociation increased the measured anti-Aβ monomer concentrations in Gamunex and Gammagard. Dissociated Gamunex and Gammagard had higher anti-Aβ monomer levels than Flebogamma. Generally similar results were found for antibodies to soluble Aβ1–42 oligomers, with the exception that after antibody–antigen dissociation, only Gammagard had significantly higher antibody levels than Flebogamma. These differences in antibody concentrations to Aβ1–42 conformations (particularly to Aβ1–42 soluble oligomers, thought to be the most neurotoxic conformation of soluble Aβ) and the increased availability of these antibodies after antibody–antigen complex dissociation have important implications for IvIg treatment of AD patients.

The construction of new immunopotentiating MUC1-VNTR-C144 DNA vaccine for pancreatic cancer

Objective To construct new MUC1-VNTR-C144 DNA vaccine for pancreatic cancer and study both CTL responses and antibody responses specific to VNTR enhanced by the C144 gene. Methods DNA encoding the 144 amino acids of the N-terminus of HBV core gene was cloned and then inserted into the recombinant plasmid pcDNA3.1-VNTR/Myc-his( + ) A. C57BL/6 mice were randomly immunized intramusscularly into anterior tibialis muscle with 100 μg plasmid DNA encoding VNTR ( V group,n = 15) or VNTR/CI44 (VC group,n = 15). Mice injected with the plasmid pcDNA3.1-C144/ Myc-his( + ) A vector (C group, n = 15 ) were used as controls. Four weeks later, all mice were injected a-gain with the same solution as before. Two weeks after the last immunization, spleen cells were obtained and analyzed for cytotoxic activity 6 days after in vitro stimulation by the synthesized VNTR polypeptide (Calcein AM assay). Blood was collected for the ELISA assay of anti-VNTR antibodies. Results The specific CTL killing rate against VNTR polypeptide induced in the VC group (46.7±8.2)% was signifi-cantly higher than in the V group (34.8±3.1 ) % and the C group ( 12.9±1.2) % ( P < 0.01 ) ,indicating the C144 gene enhances the CTL response induced by the vaccine. However,CTL lysed much more VNTR positive EIA than VNTR negative EIA ( P < 0.01 ), while the anti-VNTR antibody VU 3C6 significantly restrained such activity ( P <0.01 ) ,which indicated the CTL response was specific to VNTR. The equiva-lent concentration of specific antibody against VNTR in the VC group (2810.2±308.3 ) mg/L was signif-icantly higher than the V group (2323.5±238.3) mg/L and the C group (2130.9±138.5) mg/L (P < 0.01 ),which implied that the C144 gene could enhance the antibody response induced by the vaccine. Conclusion The VNTR specific CTL response and antibody response induced in mice immunized with new MUCl-VNTR-C144 DNA vaccine for pancreatic cancer can be enhanced significantly by the C144 gene. Key words: Pancreatic carcinoma; DNA vaccine

Experimental verification of the model of complement-dependent immune lysis of liposomes

The quantitative dependences of the immune complement-dependent lysis of a monodisperse suspension of 200-nm liposomes whose membrane was sensitized by monovalent hapten (2,4-DNP-epsilon-caproyl-DPPE) or a polyvalent antigen (LPS from F. tularensis) on the initial concentration of specific antibodies (IgG) to hapten and the antigen have been investigated. The quantity of antibodies binding sites on the surface of liposome was evaluated. The difference between the complement-dependent immune lysis of poly- and monodisperse suspensions of liposomes was shown. The experimental results are well described by the direct binding model.

A novel recombinant tandem repeat DNA vaccine targeting at MUC1

3066 Background: Tandem repeat (TR) is the key epitope of mucin 1 (MUC1) for inducing cytotoxic T lymphocytes (CTL) to kill the tumor cells specifically. A novel recombinant TR DNA vaccine was constructed to study its induced immune responses. Methods: A recombinant human TR (rhTR) gene encoding a single TR polypeptide of MUC1 was synthesized and cloned into the multiple cloning sites of plasmid pcDNA3.1/Myc-his (+) A to construct the recombinant plasmid pcDNA3.1-TR/Myc-his (+) A (pTR plasmid). Expression of pTR plasmid was confirmed by transfection assay and Western blot analysis. C57BL/6 (H-2b) mice were immunized with pTR plasmid (n=15) by tibial muscle injection. Mice inoculated with the empty vector (EV group, n=15) and 0.9% NaCl solution (NS group, n=15) were used as vector and blank control respectively. Four weeks later, all mice were immunized again. Specific antibody detection and cytotoxic assay were used to evaluate the vaccine-induced TR specific immune responses. Results: DNA sequencing confirmed that the pTR plasmid was exactly constructed. Transfection assay and Western blot analysis found that the transfected COS7 cells expressed TR polypeptide of MUC1 48 hours after transfection. Cytotoxic assay showed that immunization with pTR plasmid into C57BL/6 mice resulted in more efficient induction of CTL specific cytolysis against TR polypeptide than that of EV group and NS group (p&lt;0.01). Vaccine immunized mice had a higher equivalent concentration of anti-TR specific antibodies (2324μg/ml±238μg/ml) than that of EV group (1896μg/ml±533μg/ml, p&lt;0.01) and NS group (1736μg/ml±142μg/ml, p&lt;0.01). Conclusions: The novel recombinant TR DNA vaccine targeting at MUC1 was exactly constructed, immunization with which could induce TR specific CTL response and antibodies response in mice. No significant financial relationships to disclose.

Cytometric Approach for Detection of Encephalitozoon intestinalis , an Emergent Agent

Encephalitozoon intestinalis is responsible for intestinal disease in patients with AIDS and immunocompetent patients. The infectious form is a small spore that is resistant to water treatment procedures. Its detection is very important, but detection is very cumbersome and time-consuming. Our main objective was to develop and optimize a specific flow cytometric (FC) protocol for the detection of E. intestinalis in hospital tap water and human feces. To determine the optimal specific antibody (Microspor-FA) concentration, a known concentration of E. intestinalis spores (Waterborne, Inc.) was suspended in hospital tap water and stool specimens with different concentrations of Microspor-FA, and the tap water and stool specimens were incubated under different conditions. The sensitivity limit and specificity were also evaluated. To study spore infectivity, double staining with propidium iodide (PI) and Microspor-FA was undertaken. Distinct approaches for filtration and centrifugation of the stool specimens were used. E. intestinalis spores stained with 10 microg/ml of Microspor-FA at 25 degrees C overnight provided the best results. The detection limit was 5 x 10(4) spores/ml, and good specificity was demonstrated. Simultaneous staining with Microspor-FA and PI ensured that the E. intestinalis spores were dead and therefore noninfectious. With the stool specimens, better spore recovery was observed with a saturated solution of NaCl and centrifugation at 1,500 x g for 15 min. A new approach for the detection of E. intestinalis from tap water or human feces that ensures that the spores are not viable is now available and represents an important step for the prevention of this threat to public health.

567 L’incidence des anticorps anti-toxoplasmiques chez les patients roumains

Introduction Toxoplasmosis is an anthropo-zoonosis widely spread around the earth, whose ocular complications are frequent and are often a first sign of infestation . Objectifs and Methods This is a retrospective statistic research based on the clinical survey and periodic control of a lot of 135 patients with toxoplasmosis, out of which 90 presented ocular toxoplasmosis, either admitted into hospital or treated ambulatory between 2000 and 2005 by the Medical Centre of Diagnosis and Ambulatory Treatment of the Defence Ministry Bucharest, the Ophthalmology Department of the Central Military Hospital of Bucharest and Army Center for Medical Research. Specific serological tests consisted in the determination of Ig G and Ig M antibobies by ELISA method. The concentration of specific antibodies is expressed in optical density units (ODU) being considered a titter over 0.300 ODU. Results The epidemiological study demonstrated the following: the disease occurs more often in the urban area (48 cases), in adult population (highest incidence between 30 and 39 years) and in females (52 cases). The main factors of risk in toxoplasmosis, as revealed by the case studies (where we used survey cards), are: contact with cats: 41 cases – 45,6%, raw meat consumption: 25 cases – 27,8%, combination of risk factors: 11,1% of the cases, unknown risk factors: 14 cases – 15,6%. Discussion The treatment for toxoplasmosis is done both locally and generally. In the case of multiple aetiology, the associated affections must also be taken into account. In persons with immune-deprivation even asymptomatic forms must be treated, to prevent the reactivation of latent forms. Most patients need two periods of treatment, according to their evolution and prognosis. Conclusion The therapeutic success depends on the intensity of clinical manifestations, the earliness of the diagnosis, the presence of complications, the accessibility to therapeutic resources. The fact that most cases are congenital requires better investigation and follow-up of pregnant women suspected of toxoplasmotic infestation and possibly the start of specific therapy during the pregnancy. Later on the fetus must also be investigated by analyzing the blood in the umbilical cord immediately after birth.

Pharmacokinetics of a new 10% intravenous immunoglobulin in patients receiving replacement therapy for primary immunodeficiency

Intravenous immunoglobulin (IVIg) is used in treating immunodeficiencies and autoimmune or inflammatory disorders. As manufacturing processes and storage can alter IgG molecules, pharmacokinetic assessments are important for new preparations. Thus, we studied pharmacokinetics of IgPro10, a new 10% liquid IVIg product stabilised with l-proline, in patients with common variable immunodeficiency (CVID) and X-linked agammaglobulinaemia (XLA). Patients received IgPro10 for ≥4 months (median dose of 444 mg/kg, at 3- or 4-week intervals). Median total IgG serum concentrations increased from 10.2 g/l pre-infusion to 23.2 g/l at infusion end. Serum IgG concentrations decreased in a biphasic manner; median terminal half-life was 36.6 days. Median half-lives were 33.2 for IgG 1, 36.3 for IgG 2, 25.9 for IgG 3 and 36.4 days for IgG 4. Specific antibody concentrations (anti-CMV, anti- Hemophilus influenzae type B, anti-tetanus toxoid and anti- Streptococcus pneumoniae) decreased with median half-lives of 22.3–30.5 days. IgPro10 pharmacokinetics were similar in patients with CVID and XLA, although patients with CVID showed higher levels of anti-tetanus and anti- S. pneumoniae antibodies than patients with XLA, suggesting residual specific antibody production. IgPro10 pharmacokinetics fulfilled expectations for and were similar to intact IgG products. Administration of IgPro10 at 3- or 4-week intervals achieved sufficient plasma concentrations of total IgG, IgG subclasses and antibodies specific to important pathogens.

Usefulness of Wheat and Soybean Specific IgE Antibody Titers for the Diagnosis of Food Allergy

Since the first suggestion of threshold values for food specific IgE antibody levels in relation to clinical reactivity, several authors have proposed different threshold values for different allergens. We investigated the relationship between wheat/soybean specific IgE antibody levels and the outcome of wheat/soybean allergy diagnosis in children of different ages. A retrospective study was conducted in 536 children admitted consecutively to our clinic with the suspicion of wheat and/or soybean allergy. The children underwent an oral food challenge and blood samples for specific IgE measurement were obtained. The children who reacted to the oral food challenge had higher specific IgE titers to the specific allergen compared to the non-reacting group. The risk for reaction increased 2.33-fold (95% CI 1.90-2.87) for wheat and 2.08-fold (95% CI 1.65-2.61) for soybean, with increasing levels of specific IgE. A significant difference between the ages of subjects pertained only to wheat. We found a relationship between the probability of failed challenge and the concentration of IgE antibodies to both wheat and soybean. Age influences the relationship of allergen specific IgE levels to wheat and oral food challenge outcome. Younger children are more likely to react to low levels of specific IgE antibody concentration to wheat than older children.

Specific immune milk production of cows implanted with antigen-release devices

A new antigen-release device (ARD) that can be implanted to enhance the titer of specific IgG and concentration of total IgG in milk of lactating cows was evaluated. An immunostimulating complex-based vaccine in the core of the ARD was made from the adjuvant Quil A and type XIII lipase from Pseudomonas spp. with a polylactide acid capsule that was used to control antigen release. Forty lactating Holstein dairy cows were divided into 2 groups (n = 20). All cows in the test group were implanted in the right iliac lymph node with 3 types of ARD at the same time, which were designed to release antigens on different days. The other group was used as a control with no implantation. The 3 ARD were designed to release the antigen on d 0, 14, and 28 after implantation. Specific IgG titers in whey and serum were measured by indirect ELISA, and total IgG concentrations were measured using sandwich ELISA. The results indicated that ARD implantation brought no negative effects on the health status, production performance of cows, and caused neither subclinical nor acute mastitis. The levels of specific IgG in serum (200,000±45,000 vs. 1,200±360) and whey (41,000±6,000 vs. 820±210) increased in the cows implanted with ARD. Specific IgG in whey was increased after 9 d. The dynamics of specific IgG titer demonstrated a pattern with the release of the antigen from 3 types of ARD. The average ELISA titer of test group in whey was 41,000±6,000, which suggested high efficiency of immune milk production caused by the ARD implantation. For total IgG in milk, greater concentration in the test compared with the control cows occurred from 11 to 20 d following implantation. The IgG mass was consistent with the dynamics of specific IgG titer and was higher from 15 to 30 d between test and control group (7.89±1.34 vs. 6.48±1.17g). In conclusion, ARD implantation was effective in improving specific antibody concentration in serum and whey. Furthermore, the whey:serum ratio of specific IgG titer, the milk:serum ratio of total IgG concentration and total IgG mass in milk suggested that a transiently upregulated IgG transfer occurred after ARD implantation.

Enhancing effects of the chemical adjuvant levamisole on the DNA vaccine pVIR-P12A-IL18-3C

DNA-based vaccination is an attractive alternative for overcoming the disadvantages of inactivated virus vaccines; however, DNA vaccines alone often generate only weak immune responses. In this study, the efficacy of LMS as a chemical adjuvant on a DNA vaccine (pVIR-P12A-IL18-3C) encoding the P1-2A and 3C genes of the FMDV and swine IL-18, which provides protection against FMDV challenge, was tested. All test pigs were administered booster vaccinations 28 days after the initial inoculation, and were challenged with 1000 ID50 FMDV O/NY00 20 days after the booster vaccination. Positive and negative control groups were inoculated with inactivated virus vaccine and PBS respectively. The DNA vaccine plus LMS induced greater humoral and cell-mediated responses than the DNA vaccine alone, as evidenced by higher concentrations of neutralizing and specific anti-FMDV antibodies, and by higher concentrations of T-lymphocyte proliferation and IFN-y production, respectively. FMDV challenge revealed that the DNA vaccine plus LMS provided higher protection than the DNA vaccine alone. This study demonstrates that LMS may be useful as an adjuvant for improving the protective efficiency of DNA vaccination against FMDV in pigs.

Utility of ovomucoid-specific IgE concentrations in predicting symptomatic egg allergy

Children with allergy to raw egg white might tolerate low amounts of heated egg. Ovomucoid-specific IgE antibodies have been suggested to be predictors of whether children could tolerate heat-treated egg. The aim was to evaluate the clinical usefulness and added diagnostic value of measurements of IgE antibodies to egg white, ovalbumin, and ovomucoid in children with egg allergy. One hundred eight patients (median age, 34.5 months) with suspected egg allergy underwent double-blind, placebo-controlled food challenges with raw and heated egg. The outcomes of the challenges were related to the serum concentration of specific IgE antibodies and total IgE by using ImmunoCAP. Reactions to heated egg white were observed in 38 patients (considered allergic to raw and heated egg), 29 patients reacted to only raw egg white, and 41 patients were tolerant. Correlation was observed between the serologic parameters studied. Receiver operating characteristic analysis showed that egg white ImmunoCAP was useful in the diagnosis of allergy to raw egg white. The positive decision point, based on 95% clinical specificity, was 7.4 kU(A)/L, and the negative decision point, based on 95% clinical sensitivity, was 0.6 kU(A)/L. For reaction to heated egg white, ovomucoid ImmunoCAP was superior. The positive decision point was 10.8 kU(A)/L, and the negative decision point was 1.2 kU(A)/L. Quantitative measurements of specific IgE antibodies to both egg white and ovomucoid and the evaluation against the suggested positive and negative decision points for specific IgE will be useful in the diagnosis of egg allergy.

Immunization in children with cancer

Children treated for cancer are immunosuppressed during treatment and for a variable period after completion of chemotherapy. There is reduction of vaccine-antigen specific antibody concentration after completion of chemotherapy. This is a practical review of immunisation of children during and after completion of chemotherapy.

Promotion of immunity of mice to Pasteurella multocida and hog cholera vaccine by pig interleukin-6 gene and CpG motifs

A novel oligodeoxynuleotides containing 11 CpG motifs was synthesized and inserted into the VR1020 plasmid containing pig interleukin-6 (IL-6) gene (VPIL6) to construct recombinant plasmid, VPIL6C. The chitosan nanoparticles (CNP) were prepared by ionic cross linkage to entrap the VPIL6C (VPIL6C-CNP), VPIL6 (VPIL6-CNP) and CpG (CpG-CNP). 42-Day old female mice were divided into four groups and intramuscularly injected respectively with 6 pmol VPIL6C-CNP, VPIL6-CNP, CpG-CNP and VR1020-CNP along with the bivalent vaccines against the Pasteurellosis and hog cholera. The blood was weekly collected from mice after vaccination to detect the changes of immunoglobulins, specific antibodies, IL-2, IL-4, IL-6 and immune cells. 28 days after vaccination, the mice were orally challenged with virulent Pasteurella multocida. The results showed that in comparison with those of the control VR1020 group, the content of immunoglobulins, specific antibodies and interleukins significantly increased in the sera from the treated two groups (P<0.05). Meanwhile, the number of lymphocytes and monocytes also remarkably elevated in the treated groups (P<0.05). The immune responses of VPIL6C mice were notably stronger than those of VPIL6 and CpG group. The challenge results proved that the overall immunity was further promoted in the treated mice which resisted the challenge infection; while the control mice manifested evident symptoms and lesions, and died of infection. These suggested that VPIL6C-CNP could better promote the immunity and resistance of mice against Pasteurellosis than VPIL6-CNP and CpG-CNP, and facilitate the development of effective adjuvant to enhance the immunity of animal against infection.

Sensitivity and specificity of recombinant ω‐5 gliadin‐specific IgE measurement for the diagnosis of wheat‐dependent exercise‐induced anaphylaxis

A recent study has shown that the measurement of specific IgE antibodies to B-cell epitope peptides of wheat omega-5 gliadin (Pep A) and high molecular weight glutenin subunit (Pep B) are useful to diagnose wheat-dependent exercise-induced anaphylaxis (WDEIA). We sought to compare the sensitivity and specificity of the in vitro tests for measuring the specific IgE antibodies to recombinant omega-5 gliadin (romega-5 gliadin) with those for wheat, gluten, Pep A, and Pep B in identification of patients with WDEIA. Fifty patients with WDEIA, 25 healthy subjects and 25 patients with atopic dermatitis with specific IgE antibodies to wheat but without experience of allergic reactions after ingestion of wheat products were enrolled in this study. The concentrations of specific IgE antibodies were measured using ImmunoCAP. The empirical receiver operating characteristics curves (ROC) for each test were prepared and the areas under the ROC curve (AUC) were compared. In patients with WDEIA, the sensitivities of the allergen-specific IgE tests for wheat, gluten, Pep A, Pep B and romega-5 gliadin were 48%, 56%, 76%, 22%, and 80%, respectively. The seven of 10 WDEIA patients with no specific IgE antibodies to romega-5 gliadin had specific IgE antibodies to Pep B. The highest AUC (0.850) was observed in the test for romega-5 gliadin. Measuring the concentration of specific IgE antibodies to romega-5 gliadin is more useful than to wheat, gluten, or Pep A in the identification of patients with WDEIA.

Comparative evaluation of two commercial enzyme immunoassays for serodiagnosis of human parvovirus B19 infection

The present study describes the performance of two commercial enzyme immunoassays (EIAs) employing recombinant capsid proteins derived from baculovirus or from yeast for diagnosis of human parvovirus B19 (B19) infection. At first, 450 sera from routine daily practice submitted consecutively for B19 antibody testing during a 2-week period in March 2006 were tested. Eighty percent of the routine sera were from pregnant women. There was a high degree of accordance between the two assay systems in detection of B19 IgG antibodies (98.9%) and B19 IgM antibodies (98.7%). Specific antibody concentrations of serum specimens with discordant test results ( n = 11) were within or close to the equivocal range of the respective assay. Subsequently, specificity and sensitivity of the IgM EIAs were assessed in detail by testing 160 sera collected from patients with a defined disease state. Specificity ranged between 94.2 and 98.5% in patients ( n = 70) with other acute infections or autoimmune diseases. In sera from pregnant women ( n = 30) and children ( n = 30) with acute B19 infection, both assays were 100% sensitive. Whereas sensitivity varied from 63.0 to 70.0% in pregnant women ( n = 30) investigated 8–12 weeks after onset of disease. According to our evaluation the diagnostic performance of the two assay systems appears to be substantially equivalent. Fetal hydrops is sometimes a late complication of gestational B19 infection and maternal B19 IgM antibodies may already have declined to undetectable levels at the time of clinical diagnosis. A negative B19 IgM test during pregnancy should therefore be interpreted with caution.

Enhancement of immunity to an Escherichia coli vaccine in mice orally inoculated with a fusion gene encoding porcine interleukin 4 and 6

Experiments were conducted to investigate the effect of a fusion gene of porcine IL-4 and IL-6 (PIL4/IL6) packaged with chitosan nanoparticles (CNPs) in terms of the development of a novel effective adjuvant. The IL4/PIL6 fusion gene was constructed and inserted into a eukaryotic expression vector. The plasmid was bound to CNP and then utilized to orally inoculate 21-day-old female Kunming mice that simultaneously received intramuscular injection of inactivated Escherichia coli vaccine. At 35 days post-vaccination, the mice were challenged by oral feeding with virulent O139: K88 strain EPEC E. coli bacteria. Compared with those of control mice, the content of immunoglobulins and specific antibodies to E. coli increased significantly in the sera of mice immunized with VPIL4/IL6-CNP ( P < 0.05). Furthermore, the levels of IL-2, IL-4 and IL-6 increased remarkably in the sera of immunized mice ( P < 0.05). After challenge, these immunological markers were elevated to different degrees in the mice immunized with the fusion gene construct (IL4/VPIL6–CNP) or individual plasmids (VPIL4 + VPIL6–CNP). The immunized mice all survived the challenge and did not show any symptoms or lesion, whereas the VR1020-CNP control mice manifested obvious clinical symptoms and hemorrhagic lesions in the digestive tracts. These results demonstrated that VPIL4/IL6 entrapped with CNP is a novel promising adjuvant to promote specific immunity and resistance of animals against infectious pathogen.