Differences In Antibody Levels Research Articles

Abstract 3772A: Merkel cell polyomavirus infection in Merkel cell carincoma

Abstract OBJECTIVE: The newly discovered Merkel cell polyomavirus (MCV) may play a role in the etiology of Merkel cell carcinoma (MCC), a rare neuroendocrine malignancy of the skin, as several studies have demonstrated MCV DNA in tumor tissues. However, MCV serologic data are sparse, with few studies investigating MCV DNA in tumor tissues and MCV antibodies within the same patients, and no published data on antibodies to MCV T-antigen. We conducted a pilot study to evaluate MCV antibody profiles in MCC cases versus controls and to examine the correlation between MCV DNA in tumors and MCV seroreactivity. METHODS: Plasma samples were obtained from 33 patients diagnosed and/or treated for MCC at the Moffitt Cancer Center in 2006-08, including 25 males and 8 females, ages 53-88 years. Controls were comprised of 37 patients undergoing routine skin cancer screening exams who had no history of skin cancer and were determined to be negative for all types of non-melanoma skin cancer (NMSC) by a nurse practitioner. Fresh-frozen tumor tissue was obtained from 15 MCC patients, including 9 from whom plasma was also obtained. Virus-like particle-based enzyme linked immunosorbent assays (ELISA) were used to measure IgG and IgA antibodies to the MCV VP1 capsid protein. Levels of IgG directed against MCV large T-antigen were also measured using ELISA. MCV DNA was measured in MCC tumor tissues using real-time polymerase chain reaction for the amplification of the small T-antigen region of the MCV genome. Differences in antibody levels across groups were assessed using Wilcoxon rank sum test. RESULTS: Levels of IgG directed against the MCV capsid protein were higher among MCC cases than healthy controls (mean (SD)= 1876 (4001) in cases, 1521 (4889) in controls; p=0.005), as were levels of MCV capsid IgA (mean (SD) = 0.21 (0.25) and 0.09 (0.15) p=0.005). Although levels of IgG antibodies directed against the large T-antigen were slightly higher among MCC cases compared to healthy controls (mean (SD) =0.25 (0.27) vs. 0.19(0.07)), this difference was not statistically significant. MCV DNA was observed in 10 (67%) of 15 tumor tissues tested, with viral loads ranging from 7.1 to 15.6 viral copies per cell equivalent. Levels of IgG antibodies directed against MCV capsid and T-antigen were higher among the 6 MCV DNA-positive cases than the 3 MCV DNA-negative cases for whom plasma was available (mean (SD): capsid IgG: 1040 (1210) in MCV DNA-positive, 384 (494) in MCV DNA-negative, p=0.52; T-antigen IgG: 0.26 (0.26) in MCV DNA-positive, 0.15 (0.15) in MCV DNA-negative, p=0.52). CONCLUSION: MCV seroreactivity is associated with MCC, and MCV antibody levels are higher among MCC patients with MCV DNA-positive tumor tissues. A larger study is needed to confirm these associations with greater statistical power and provide the evidence needed to establish causality between MCV infection and MCC. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3772A.

Autoimmune response to heat shock protein 60 in haemodialysis patients

Dear Sir,We read with great interest the paper by Gruden et al. [1] recently published in Journal of Internal Medicine. The authors reported a significant inverse correlation between diabetic micro- and macroangiopathy and serum levels of anti-Heat Shock Protein 70 (HSP70) antibodies in a large cohort of type 1 diabetic patients. HSP70 levels resulted higher in healthy subjects compared with diabetic patients, while no significant difference was found in anti-HPS60 levels between patients and controls. In a longitudinal study, we investigated whether anti-HSP60 antibodies are associated with cardiovascular risk in adult patients on haemodialysis (HD). We evaluated anti-HSP60 serum levels in 33 nondiabetic patients (66.5 ± 10.4 years, m/f: 17/16) on regular HD. Then, we correlated the titer of the antibodies to cardiovascular risk factors, inflammation and incidence of cardiovascular events, during a 24-month follow-up. Cardiovascular risk factors considered were: smoking habit, diabetes, systolic blood pressure and serum cholesterol. Inflammation was assessed by high sensitivity C-Reactive Protein (hs-CRP) serum levels. Thirty healthy sex-age matched subjects (63.3 ± 7.7 years, m/f: 15/15) were the controls. Anti-HSP60 serum levels were measured by ELISA that detected IgG, IgA and IgM isotypes (Stressgen Biotechnologies Corporation,Victoria, BC, Canada). Anti-HSP60 were present in all analysed subjects; there was no significant difference in antibody levels between patients and controls (41.84 ± 34.78 vs. 38.47 ± 11.34 μg mL−1, respectively). Furthermore, anti-HSP60 did not correlate neither to hs-CRP serum levels nor to cardiovascular risk factors and incidence of cardiovascular events. Many studies have been focussed on the pathogenic or predictive role of anti-HSP60 antibodies in patients with ischaemic heart disease, with contrasting results [2–4]. We found no predictive role of anti-HSP60 in adult patients on regular HD, i.e. a population with a cardiovascular risk 20 to 30 times higher than in general population [5]. Our finding fits with the report of Gruden et al. in diabetic patients and add further doubt about a relevant pathogenic role of an autoimmune response to HSP60 in atherosclerosis. All authors state no conflict of interest.

Review article: Hepatitis B and dialysis

The incidence of hepatitis B virus (HBV) infection in dialysis populations has declined over recent decades, largely because of improvements in infection control and widespread implementation of HBV vaccination. Regardless, outbreaks of infection continue to occur in dialysis units, and prevalence rates remain unacceptably high. For a variety of reasons, dialysis patients are at increased risk of acquiring HBV. They also demonstrate different disease manifestations compared with healthy individuals and are more likely to progress to chronic carriage. This paper will review the epidemiology, modes of transmission and diagnosis of HBV in this population. Prevention and treatment will be discussed, with a specific focus on strategies to improve vaccination response, new therapeutic options and selection of patients for therapy.

Breastfeeding stimulates total and cow’s milk‐specific salivary IgA in infants

Breastfeeding may increase the rate of mucosal maturation and IgA production. We sought to determine the effect of breastfeeding vs. formula-feeding on the maturation of oral mucosa by measuring the salivary total antibodies and cow's milk protein-specific IgA. Fifty-eight saliva samples were collected from 39 healthy, full term infants. At the age of 3 months (n = 25) eight infants received only breast milk and seventeen formula (cow's milk based n = 10, hydrolysed n = 7) and breast milk; and at the age of 6 months (n = 33) eleven received breast milk, seventeen formula and breast milk and five were not breastfed any more (cow's milk based n = 14, hydrolysed n = 8). Total IgA, IgG, IgM and protein, and beta-lactoglobulin specific IgA were measured from saliva with enzyme-linked immunoassay (ELISA). The antibody results were proportioned to total protein. No differences in antibody levels between the feeding groups were found at 3 months of age. At 6 months, total IgA, total IgM and beta-lactoglobulin-specific IgA were higher among the breastfed infants compared to those receiving formula as supplement to breast milk or not breastfed any more (breast milk vs. any formula p = 0.029, p = 0.015, p = 0.058; breast milk vs. cow's milk formula p = 0.025, p = 0.044, p = 0.038). To conclude, breastfeeding stimulated the mucosal immune system to produce IgA to saliva, which is a marker for immunological maturation and likely provides protection against environmental antigens.

Anti-PGL-Tb1 responses as an indicator of the immune restoration syndrome in HIV-TB patients

A prospective and multi-centre study has allowed us to analyse antibody responses and Mycobacterium tuberculosis clinical isolate genotypes on 24 consecutive HIV-TB co-infected patients treated with Highly Active Antiretroviral Therapy (HAART) who either went on to develop a TB Immune Restoration Syndrome (TB-IRS), or not. Circulating free and immune-complexed antibodies against ManLAM, ESAT-6/CFP10 and PGL-Tb1 in HIV-TB co-infected patients were measured by ELISA at the initiation of anti-TB treatment, at the date of HAART initiation and thereafter. Presence of circulating B cells was also monitored by in vitro antibody production (IVAP) against ESAT-6/CFP10 and PGL-Tb1. Finally, 16 out of 24M. tuberculosis clinical isolates from patients with TB-IRS were genotyped using spoligotyping and MIRUs-VNTR typing. Eleven patients (45.8%) experienced TB-IRS (TB-IRS+). Significantly, lower anti-PGL-Tb1 antibody levels were identified in TB-IRS+ compared to TB-IRS-negative patients prior to TB-IRS development. These very low levels were neither related to CD4 counts nor with complexed antibodies. No difference in antibody levels was observed with the other tested antigens. In addition, no specific strain genotype was associated with TB-IRS. The presence of specific anti-PGL-Tb1 antibodies only in TB-IRS-negative patients represents for the first time an indicator of a potential protective response or a diagnostic biomarker for the detection of non-progression to TB-IRS in HIV-TB co-infected patients starting HAART.

Schizophrenia and toxoplasmosis.

Schizophrenia and toxoplasmosis.

Humoral response to hemagglutinin components of influenza vaccine in patients with non-Hodgkin malignant lymphoma

Lymphoma disease and immunosuppressive drugs used in this case cause immunity disorders increasing the risk of severe infections, including influenza. There are opinions that patients from high-risk group are not able to respond to vaccination effectively and vaccination may contribute to exacerbation of the chronic disease. The aim was to assess humoral response to influenza vaccine in 32 patients with non-Hodgkin malignant lymphoma (mean age 57.2) and 32 healthy subjects (mean age 44.3). Sixteen patients were treated with immunosupressive drugs (group A) and 11 were not subjected to this therapy (group B). Levels of antihemagglutinin (anti-HA) antibodies were assessed in sera before vaccination and after 1 month by hemagglutination inhibition test. Nasal and throat swabs were collected from persons with influenza symptoms during the study to detect the etiological agent of the infection. Post-vaccination anti-HA antibody levels were significantly higher than pre-vaccination values and mean fold increases (MFI) ranged from 9.3 to 12.2 in patients and from 27.6 to 44.3 in healthy subjects. The percentage of patients with the protective anti-HA antibody titers ≥1:40 (protection rate) ranged after vaccination from 59.4% to 68.8%. The percentage of patients with at least a four-fold increase of anti-HA antibody titers (response rate) after vaccination ranged from 46.9% to 68.8%. There were no significant differences in antibody levels between patients treated with immunosuppressive drugs and those not treated. No respiratory infections were laboratory confirmed. This study showed that influenza vaccine is less immunogenic in patients with non-Hodgkin malignant lymphoma, because it induces antibody production in lower titers in comparison to the production in healthy people. Despite this, influenza vaccine should be offered to this group, considering high MFI values and response rates as well as the protective effect for individual patients.

The reactivity of paired plasma and serum samples are comparable in the anticardiolipin and anti‐β2‐glycoprotein‐1 ELISAs. Reply to a rebuttal

We thank Wong and Favaloro for suggesting an alternate method for displaying and analyzing our data concerning the reactivity of paired plasma and serum samples in the anticardiolipin (ACL) and anti‐β2‐glycoprotein‐1 (anti‐β2GP1) ELISAs [1Wong R.C. Favaloro E.J. The reactivity of paired plasma and serum samples are comparable in the anticardiolipin and anti‐β2‐glycoprotein‐1 ELISAs: a rebuttal.J Thromb Haemost. 2006; 4: 1434-5Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar]. The ELISA data from our original report have now been analyzed using Bland–Altman difference plots (Fig. 1A–D) [2Lewis D.A. Pound M.L. Ortel T.L. The reactivity of paired plasma and serum samples are comparable in the anticardiolipin and anti‐β2‐glycoprotein‐1 ELISAs.J Thromb Haemost. 2006; 4: 265-7Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar, 3Bland J.M. Altman D.G. Statistical methods for assessing agreement between two methods of clinical measurement.Lancet. 1986; 1: 307-10Abstract PubMed Scopus (39517) Google Scholar]. The mean difference of the antibody levels in the two pairs of sample types (value detected in plasma sample minus value detected in serum sample) and 95% limits of agreement for these values are shown as dashed lines on the graphs and are listed in the figure legend. The mean differences for both sample pairs in both ELISAs are relatively small (−0.91–1.89 GPL units) and vary in a random manner, indicating that the sample pairs behave similarly in each of the ELISAs. The absolute values of 95% limits of agreement for the samples pairs are within 18 GPL units for the ACL ELISA and 30 anti‐β2GP1 units for the anti‐β2GP1 ELISA, indicating that the differences we found in the antibody values determined using the different sample types are not clinically relevant. As expected, the mean differences between the sample types in both ELISAs were greater at higher antibody levels. If antibody levels above 100 GPL or 100 anti‐β2GP1 units are excluded from the analysis, the absolute values of 95% limits of agreement are < 12 GPL or 12 anti‐β2GP1 units for both sample pairs in both assays (data not shown). Wong and Favaloro also raised concerns about dilution artifacts in plasma samples. In our original letter the antibody levels determined using citrated plasma samples were corrected for dilution of samples (collection of blood using ethylenediamine‐tetraacetic acid (EDTA) as an anticoagulant does not result in dilution of the sample). We do note, however, that the mean differences in antibody levels and the 95% limits of agreement for the two sets of sample pairs for both ELISAs are greater for citrated plasma and serum pairs compared with the EDTA plasma and serum pairs (Fig. 1A–D). It is unlikely that this difference reflects only a dilution artifact as the results vary in a random manner. Analysis of our data using different plots supports our original conclusion that the reactivity of plasma and serum is comparable in the ACL and anti‐β2GP1 ELISAs developed in our laboratory. These data would suggest that it is valid to compare antigen levels in datasets containing a combination of citrated plasma, EDTA plasma and serum samples. Our interest in this comparison was to confirm the ability to identify ACL and anti‐β2GP1 antibodies in different plasma and serum samples for future research studies. For clinical laboratory testing we would agree with adhering to the recommended laboratory practices and not mixing sample preparations. This work was supported by a cooperative agreement (U18DD00014) with the Hematologic Diseases Branch, Centers for Disease Control and Prevention (T. L. Ortel), and grant (U54‐HL077878) from the National Institutes of Health (T. L. Ortel).

Antibody Response to Inhaled Insulin in Patients with Type 1 or Type 2 Diabetes. An Analysis of Initial Phase II and III Inhaled Insulin (Exubera) Trials and a Two-Year Extension Trial

To compare antibody responses to inhaled human insulin vs. sc human insulin and to determine whether insulin antibody binding is associated with adverse clinical consequences. Insulin antibody data from initial phase II/III trials were analyzed comparing the efficacy and safety of inhaled insulin with various agents, including sc insulin. Additionally, data from a 24-month extension of the phase III studies were examined. Data were pooled into the following three groups based on insulin treatment status at baseline: patients with type 1 diabetes, and patients with type 2 diabetes using insulin and not using insulin at baseline. Ig class analysis was also performed on randomly selected sera from type 1 patients at the end of the initial trials. In the initial trials, greater insulin antibody binding was observed in patients receiving inhaled insulin vs. sc insulin. The greatest antibody responses to inhaled insulin were observed in patients with type 1 diabetes [nonparametric comparison of medians at the end of the study, 22.0% binding (unadjusted 95% confidence interval: 19.5, 24.5)], and the lowest responses were observed in non-insulin-using patients with type 2 diabetes in which there was no difference in median values at the end of the study. There were no correlations between antibody binding and glycemic control (measured using glycosylated hemoglobin), insulin dose requirements, hypoglycemic events, or pulmonary function (measured by changes in forced expiratory volume in 1 sec and diffusion capacity of carbon monoxide). Antibody responses were IgG in type. Differences in antibody levels observed in patients with type 1 vs. type 2 diabetes were maintained over the 24-month extension trials. Peak antibody levels across all groups were generally observed after 6-12 months of insulin therapy. Inhaled insulin therapy was not associated with a greater incidence of allergy or other hypersensitivity reactions. Inhaled insulin was observed to produce a larger antibody response than sc insulin. Insulin antibody binding has not been associated with adverse clinical consequences in trials to date.

Evidence for antigen production in muscles by dengue and Japanese encephalitis DNA vaccines and a relation to their immunogenicity in mice

This study demonstrated viral antigen production in muscle tissues following inoculation with DNA vaccines and examined its relation to antibody induction in mice using the flavivirus system. To achieve detectable levels of antigen production, we used a needle-free jet injector and examined 10% homogenate of quadriceps muscle for viral antigens in a sandwich enzyme-linked immunosorbent assay. We compared DNA vaccines against dengue type 1 (designated pcD1ME), dengue type 2 (pcD2ME) and Japanese encephalitis (pcJEME). The amounts of viral envelope (E) antigen contained in muscle homogenate 1, 2, 3 and 4 days following inoculation with 50μg of pcJEME were 1.1, 1.0, 0.3 and <0.1ng/ml, respectively. Muscles from pcD2ME- and pcD1ME-inoculated mice did not contain detectable levels of E antigen (<0.1ng/ml) during 4 days following inoculation. The E amounts released from Vero cells transfected with DNAs were in the order pcJEME>pcD2ME>pcD1ME. Levels of neutralizing antibody induced by two immunizations with 100μg of each DNA vaccine using needle-free or normal needle/syringe injection systems also were in the order pcJEME>pcD2ME>pcD1ME, 2–11 weeks after the first immunization. However, the difference in antibody levels among three DNA vaccines 14–18 weeks after immunization was smaller than that in the early phase of immunization. These results provide fundamental information useful for developing combination DNA vaccines, such as a dengue tetravalent DNA vaccine, which require adjustment of immunogenicity of each component.

Respiratory disease in kennelled dogs: serological responses to Bordetella bronchiseptica lipopolysaccharide do not correlate with bacterial isolation or clinical respiratory symptoms.

The role of Bordetella bronchiseptica in a natural outbreak of canine infectious respiratory disease was investigated both by culture and serological analysis. B. bronchiseptica was found in the lungs of a large proportion of clinically healthy dogs and in a greater proportion of dogs with respiratory disease. Using a lipopolysaccharide (LPS) antigen-based enzyme-linked immunosorbent assay, we analyzed the serological responses of a large number of dogs. Dogs with high antibody levels showed no protection from disease, and there was no correlation between the development of disease and rising antibody titer. Similarly, there was no difference in antibody levels in dogs with and without B. bronchiseptica in the lungs. Antibodies to LPS have no predictive value in determining which animals will contract respiratory disease, how severe the disease will be, or which dogs will have B. bronchiseptica colonizing the lungs.

Immunoglobulin G antibody against Helicobacter pylori: clinical implications of levels found in serum.

The clinical significance of high levels of antibody against Helicobacter pylori is still unclear. We sought to evaluate whether the serum antibody levels could predict the presence of macroscopic gastroduodenal disease, to identify factors that correlate with antibody levels in a multivariate context, and to determine the predictive value of antibody levels for diagnosing H. pylori infection. The grades of gastritis and density of H. pylori colonization were scored separately using the updated Sydney system for antral and body mucosa. An enzyme-linked immunosorbent assay (ELISA) for the quantitative detection in serum of IgG antibodies to H. pylori was performed. Of the 170 dyspeptic patients, 105 (62%) had H. pylori infection. There was no difference in antibody levels among endoscopic findings of normal mucosa, chronic gastritis, and duodenal ulcer. On multivariate linear regression analysis, the status of H. pylori infection, mononuclear cell infiltration of body mucosa, and age correlated with antibody levels. The negative predictive value for antibody levels of <30 U/ml is 94%, and the positive predictive value of antibody levels of >70 U/ml is 98%. We conclude that serum antibody levels do not predict the severity of gastroduodenal diseases or the density of H. pylori colonization in H. pylori-infected dyspeptic patients. Higher levels are associated with the presence of H. pylori infection, the chronic gastritis score of the corpus, and older age. Setting a gray zone is necessary for ELISA, since the accuracy in this zone does not allow a precise determination of H. pylori status.

Differentiation of entamoeba histolytica/entamoeba dispar by PCR and their correlation with humoral and cellular immunity in individuals with clinical variants of amoebiasis.

To correlate a particular state of immunity with Entamoeba spp., we used colorimetric PCR to differentiate E. histolytica from E. dispar in individuals with amoebiasis and to associate its presence with the clinical profile, including humoral and cellular immune responses to E. histolytica. Our results showed high levels of antibody in acute amoebiasis and elevation of IL-4 production, a cytokine related to Th2 profile, associated with E. histolytica. In chronic amoebiasis, even with anti-E. histolytica seropositivity, intestinal symptoms were associated with E. dispar in all the cases, without differences in level of antibodies, BTI, CD4+/CD8+ ratio, INF-gamma, and IL-4. Among asymptomatic carriers, E. dispar was more frequently found; however, identification of E. histolytica in two asymptomatic carriers associated with high levels of INF-gamma, a cytokine related to Th1 profile, demonstrate the importance of making specific diagnosis of Entamoeba spp., to establish the clinical and epidemiological behavior in both intestinal and extra-intestinal amoebiasis.

The effect of pasture species on parasitism and performance of lambs grazing one of three grass—white clover pasture swards

Lamb parasitism and performance were compared on three pasture treatments: browntop/white clover, Yorkshire fog/white clover, and ryegrass/white clover swards maintained at a sward height of 5 cm in each of two years by using continuous variable stocking management. In year 1, lamb performance (both suppressively drenched (SD) and trigger drenched (TD)) was similar on ryegrass and browntop swards but was poorer ( P<0.05) on Yorkshire fog swards. In year 2, lamb performance (both SD and TD) was markedly better on ryegrass than on Yorkshire fog or browntop swards. This coincided with an increase in white clover content in the ryegrass/white clover swards and a decrease in white clover content in the browntop/white clover swards. Lamb performance was related to the white clover content of the swards ( R 2=85.4, P<0.001 and R 2=77.5, P<0.001 for SD lambs and TD lambs, respectively). Differences among pasture treatments in faecal egg count (FEC) of TD lambs were greater in year 2 than in year 1 when no significant pasture effects were observed. In year 2, FEC was lowest in lambs which grazed ryegrass/white clover, intermediate in those which grazed Yorkshire fog/white clover and highest in lambs which grazed browntop/white clover, despite herbage allowance (kg herbage mass/kg lamb mass) being greater on the browntop/white clover and Yorkshire fog/white clover swards than the ryegrass/white clover swards. Circulating antibodies to gastrointestinal parasites were measured at the end of year 2. Antibody titres were highest ( P<0.05) in the plasma of lambs which grazed ryegrass/white clover swards, and lowest in lambs which grazed browntop/white clover swards due to differences in levels of antibody to ( P<0.05) Haemonchus contortus, Ostertagia circumcincta larvae and adults, but not Trichostrongylus colubriformis larvae or adults. These findings indicate that pasture composition, especially, the proportion of white clover, can help alleviate the production losses due to gastrointestinal parasitism. This information can provide a quick and readily adoptable practice for farmers who aim to reduce drench reliance and could become a key component of any integrated parasite control programme.

Systemic antibodies to Clostridium botulinum type C: do they protect horses from grass sickness (dysautonomia)?

The aetiology of equine grass sickness (EGS) is still unknown. There is increasing evidence that toxicoinfection with Clostridium botulinum type C is involved. Epidemiological evidence shows that resistance to EGS can occur in older horses and those that have been on a particular pasture for longer or have been in prior contact with the disease. This resistance may be in the form of an immune response to the aetiological agent. Levels of systemic antibodies to the surface antigens of C. botulinum type C (using the closely related and safe C. novyi type A as a phenotypic marker) and to the botulinum type C neurotoxin (BoNT/C) were investigated in horses with and without EGS. Horses with grass sickness were found to have significantly lower levels of systemic IgG to both surface antigens and BoNT/C. Horses with low levels of systemic immunity to these antigens may be more susceptible to developing EGS. There were no significant differences in antibody levels between the different categories of EGS, suggesting systemic immunity to C. botulinum type C does not play a significant role in influencing the severity of the disease. However, horses that had been in contact with EGS or that were grazing land where it had occurred frequently in the past had significantly higher antibody levels to these antigens. These horses may have been exposed to subclinical doses of C. botulinum type C and BoNT/C, resulting in the production of a protective immune response against the putative aetiological agent. This finding is of potential significance for the prospect of prevention of EGS by vaccination against C. botulinum type C.

Validation of five commercially available ELISAs for the detection of antibodies against infectious bursal disease virus (serotype 1)

In this study, the results are reported from a validation study of five commercially available enzymelinked immunosorbent assays (ELISAs) for the detection of antibodies against infectious bursal disease virus (IBDV), serotype 1. The specificity of the ELISAs varied from 63.8 to 100%. All ELISAs reached a sensitivity of 100% on sera between 14 and 21 days post-vaccination (d.p.v.) with two classical vaccines and a Delaware variant-E virus. Overall, most birds became positive between 8 and 11 d.p.v. As expected, the ELISA with the lowest specificity showed the highest sensitivity at 5 d.p.v. When the decrease in maternally derived antibodies against IBDV was measured, a highly significant correlation (P < 0.001) was found for all ELISAs and the virus neutralization test (VNT). R 2 varied from 0.44 to 0.76, whereas the slope varied from 0.33 to 0.57. This indicates that there is a certain correlation between VNT and ELISA titres, but that the correlation differs from ELISA to ELISA. For all ELISAs, no significant (P < 0.05) differences in level of antibodies were detected between antibody titres in breeder serum, egg yolk and progeny at 1 and 4 days of age. This validation of five commercially available ELISAs for the detection of antibodies against IBDV (serotype 1) shows that there are significant differences in their performance. Therefore, choosing an ELISA or interpreting ELISA results without knowing the technical performance should be avoided.

Immunodiagnostic differentiation of alveolar and cystic echinococcosis using ELISA test with 18-kDa antigen extracted from Echinococcus protoscoleces

Immunoblotting analysis was carried out using crude extracts of Echinococcus multilocularis and E. granulosus. A total of 214 serum samples were examined for the detection of antibody responses against 18-kDa polypeptides (Eg18 and Em18). Of 44 sera from patients with alveolar echinococcosis (AE) 91% were positive against both Eg18 and Em18, compared with 10% and 13%, respectively, of 70 cystic echinococcosis (CE) samples and 13% and 17% of 29 cysticercosis samples. A relatively purified 18-kDa antigen was extracted from E. granulosus protoscoleces and an 18-kDa-ELISA test which is simple, fast and highly sensitive and specific has been established. A comparative ELISA analysis, using the purified 18-kDa antigen and pooled AE and CE serum, indicated that there are significant differences in antibody levels between AE and CE sera. The maximum ratio for the evaluation of AE to CE was 2.26. The 18-kDa-ELISA was positive for 91% (40/44) and 11% (8/70) of AE and CE sera, respectively, and there was no cross-reactivity with cysticercosis sera or healthy controls. The overall diagnostic values of 18-kDa-ELISA for AE sera were sensitivity 91%, specificity 94%, positive predictive value 83% and negative predictive value 97%. We conclude that (i) the 18-kDa antigenic component may not be species specific but (ii) levels of antibody to the 18-kDa antigen are significantly different between AE and CE sera. Therefore, the 18-kDa antigen can be a reliable serological marker for differentiation of AE from CE.

Autoantibodies to oxidized low-density lipoprotein in coronary artery disease

Background: The significance of antioxidized low-density lipoprotein (oxLDL) antibodies in atherogenesis is not yet clear, and there are conflicting data regarding anti-oxLDL levels in early hypertension. Methods: The levels of anti-oxLDL antibodies were studied in coronary artery disease patients with ( n = 82) or without ( n = 36) hypertension, in association to other risk factors for coronary artery disease. Results: The levels of anti-oxLDL antibodies did not differ significantly between coronary artery disease patients with or without hypertension. (0.132 ± 0.146 v 0.153 ± 0.158 optical density at 405 nm, respectively; P = .48). No significant differences in anti-oxLDL antibodies were found between men and women with and without hypertension, between hypertensive patients with normal and abnormal blood pressure measurements, and between medicated and nonmedicated hypertensive patients. The presence of diabetes mellitus, smoking, and hypercholesterolemia, either solely or in combination, did not result in significant differences in antibody levels in the hypertensive or normotensive patients. Conclusions: Although the levels of oxLDL antibodies might be modified in early hypertension, once advanced coronary artery disease has developed the presence of hypertension does not affect anti-oxLDL levels.

Measles antibody responses after early two dose trials in Guinea-Bissau with Edmonston-Zagreb and Schwarz standard-titre measles vaccine: better antibody increase from booster dose of the Edmonston-Zagreb vaccine

In Guinea-Bissau, children were randomised at 6 months of age to receive either two doses of standard-titre measles vaccine at 6 and 9 months of age or an inactivated polio vaccine at 6 months and standard-titre measles vaccine at 9 months of age. During the first 5 months, children received Edmonston-Zagreb (EZ) vaccine and during the following 11 months, the Schwarz (SW) vaccine. Five percent of the mothers, 74% of children at 6 months of age, and 92% of unvaccinated children at 9 months of age had unprotective levels (<125 mIU/ml) of measles antibodies. Among children receiving EZ vaccine, 1% were unprotected at 18 months of age after either two (3/240) or one (3/211) doses of vaccine, the geometric mean measles antibody titre (GMT) being ∼1550 mIU/ml in both groups. Among those receiving SW vaccine 9% (34/365) and 3% (9/310) were unprotected at 18 months of age in the two-dose and the one-dose groups (RR=3.21 (95% confidence interval (CI) 1.56–6.58)), respectively. The GMT was higher after one dose of SW vaccine at 9 months of age (2491 mIU/ml) than after two doses of SW vaccine (1125 mIU) ( P<0.001). In the EZ vaccine group, there was no significant difference in antibody level for children vaccinated in the presence of high or low levels of maternal antibodies, whereas there was a marked difference in the SW group. The second EZ vaccine induced a significant antibody increase between 9 months of age (1191 mIU) and 18 months of age (1602 mIU, P=0.011), whereas antibody levels tended to decline from 9 months (1243 mIU) to 18 months of age (998 mIU, P=0.124) after the second dose of SW vaccine. Conclusively, after two doses of EZ measles vaccine more children were protected at 18 months of age than after two doses of SW. One dose of SW provided the highest antibody response, but a higher proportion of unprotected than one or two doses of EZ. The EZ vaccine was less sensitive to maternal antibodies, and able to increase the antibody response by revaccination, while the second SW vaccine resulted in an unchanged or lower antibody response.

Antizona and antisperm antibodies in women with endometriosis and/or infertility

Objective: To measure the levels of antigamete antibodies in serum and peritoneal fluid of women with endometriosis and/or infertility. Design: Antibody activity against human sperm and porcine oocytes was analyzed in selected subgroups of women. Setting: Clinic of reproduction. Patient(s): Women with endometriosis and/or infertility. Intervention(s): No treatment was implemented before peritoneal fluid and blood sample collection. Main Outcome Measure(s): Quantitative ELISA. Result(s): Four groups of women (n = 98) were analyzed for the presence of antizona and antisperm antibodies: infertile with endometriosis (n = 30), idiopathic infertility (n = 28), fertile with endometriosis (n = 20), and healthy fertile controls (n = 20). Antibodies were analyzed simultaneously in serum and peritoneal fluid. No statistically significant differences in antibody levels were detected in serum samples among the analyzed groups. The median values for antizona and antisperm antibodies in peritoneal fluid were significantly higher in women with idiopathic infertility than in the control group. In women with unexplained infertility, a high degree of correlation (Spearman) was found between the presence of antizona antibodies in peritoneal fluid and serum ( r = 0.579). A positive predictive value of 80% was calculated for the presence of antizona antibodies (>5 ng/oocyte) in the peritoneal fluid of patients with infertility. Conclusion(s): Antizona antibodies locally produced in the peritoneal fluid have diagnostic value for infertility status; however, they cannot be treated as a marker or prognostic factor for minimal endometriosis and/or its treatment.