Search

Objective:To describe the cumulative seroprevalence of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) antibodies during the coronavirus disease 2019 (COVID-19) pandemic among employees of a large pediatric healthcare system.Design, setting, and participants:Prospective observational cohort study open to adult employees at the Children’s Hospital of Philadelphia, conducted April 20–December 17, 2020.Methods:Employees were recruited starting with high-risk exposure groups, utilizing e-mails, flyers, and announcements at virtual town hall meetings. At baseline, 1 month, 2 months, and 6 months, participants reported occupational and community exposures and gave a blood sample for SARS-CoV-2 antibody measurement by enzyme-linked immunosorbent assays (ELISAs). A post hoc Cox proportional hazards regression model was performed to identify factors associated with increased risk for seropositivity.Results:In total, 1,740 employees were enrolled. At 6 months, the cumulative seroprevalence was 5.3%, which was below estimated community point seroprevalence. Seroprevalence was 5.8% among employees who provided direct care and was 3.4% among employees who did not perform direct patient care. Most participants who were seropositive at baseline remained positive at follow-up assessments. In a post hoc analysis, direct patient care (hazard ratio [HR], 1.95; 95% confidence interval [CI], 1.03–3.68), Black race (HR, 2.70; 95% CI, 1.24–5.87), and exposure to a confirmed case in a nonhealthcare setting (HR, 4.32; 95% CI, 2.71–6.88) were associated with statistically significant increased risk for seropositivity.Conclusions:Employee SARS-CoV-2 seroprevalence rates remained below the point-prevalence rates of the surrounding community. Provision of direct patient care, Black race, and exposure to a confirmed case in a nonhealthcare setting conferred increased risk. These data can inform occupational protection measures to maximize protection of employees within the workplace during future COVID-19 waves or other epidemics.

Összefoglaló. Bevezetés: Az 1-es típusú diabetes mellitus és a coeliakia gyakori társulása jól ismert. Néhány tanulmány beszámol átmeneti antitranszglutamináz-emelkedésről 1-es típusú diabeteses betegekben, akiknél az emelkedett antitestszint gluténmentes diéta bevezetése nélkül normalizálódik. Célkitűzés: Kutatásunk során az átmeneti antitranszglutamináz-emelkedés gyakoriságának meghatározását tűztük ki célul. További célunk volt a coeliakia gyakoriságának megállapítása 1-es típusú diabetesszel gondozott betegeink között. Módszer: A Semmelweis Egyetem I. Gyermekgyógyászati Klinikáján 1-es típusú diabetesszel gondozott betegeket vontuk be vizsgálatunkba (238 lány, 265 fiú, medián [IR] életkor az 1-es típusú diabetes diagnózisakor: 7,83 [4,67–11] év). Vizsgáltuk a jelenség időbeli megjelenését, az emelkedés mértékét, gyakoriságát és az antitest típusát. Leíró statisztikai módszereket és khi-négyzet-próbát alkalmaztunk. Eredmények: A vizsgált populációban a coeliakia gyakorisága 12,52%. Átmeneti antitranszglutamináztiter-emelkedést 48 gyermeknél (10,9%) észleltünk. Összesen 71-szer mértünk átmeneti antitranszglutamináz-emelkedést. A gyermekek közül 34 esetben (70,83%) egyszer fordult elő emelkedést mutató antitest, a többi betegnél 2–8 alkalommal. Gyakrabban tapasztaltunk izolált IgA-típusú emelkedést, mint izolált IgG-típusút (54 vs. 5). Következtetés: Az átmeneti antitranszglutamináz-emelkedés gyakorisága magas, összevethető a valódi coeliakiás csoporttal. Kutatásunk alátámasztja a nemzetközi ajánlást, miszerint mérsékelt mértékű antitranszglutamináz-emelkedés esetén, tünetmentes 1-es típusú diabetesszel gondozott betegben a gluténfogyasztás folytatása és az antitestszintek gyakori kontrollja javasolt. Orv Hetil. 2021; 162(48): 1924–1930. Summary. Introduction: The frequent association of type 1 diabetes mellitus with coeliac disease is well known. Development of transitional elevation of anti-tissue transglutaminase antibodies in the diagnosis of type 1 diabetes is reported in some studies. In these cases, the anti-tissue transglutaminase antibodies returned to normal without gluten-free diet. Objective: Our aim was to assess the frequency of transitional elevation of anti-tissue transglutaminase in our type 1 diabetes patients. We aimed to investigate the prevalence of coeliac disease in patients with type 1 diabetes. Method: Patients with type 1 diabetes at the Ist Department of Paediatrics, Semmelweis University, were enrolled in the study (238 girls, 265 boys; the median age at the time of type 1 diabetes diagnosis was 7.83 [4.67–11] years). Descriptive statistical analysis was done and the time of appearance, extent, frequency and type of elevated anti-tissue transglutaminase antibodies were examined. Results: The proportion of children with diagnosed coeliac disease was 12.52%. We detected transitional anti-tissue transglutaminase elevation in 48 cases (10.9%). Temporarily elevated antibody levels were measured 71 times. In 34 children (70.83%), the temporary elevation occured once, while in the others, antibody levels became positive 2–8 times. The elevation of the IgA antibody was more frequent than the elevation of the IgG antibody (54 vs. 5). Conclusion: The frequency of temporary elevated anti-tissue transglutaminase levels is considered high. Our study confirms the recommendation that in the case of moderate anti-tissue transglutaminase levels with lack of clinical symptoms, control antibody measurement is necessary with ongoing gluten consumption. Orv Hetil. 2021; 162(48): 1924–1930.

Evaluation of antibodies produced after immunization is central to immune deficiency diagnosis. This includes assessment of responses to routine immunizations as well as to vaccines administered specifically for diagnosis. Here, we present the basic concepts of the humoral immune response and their relevance for vaccine composition and diagnosis of immune deficiency. Current vaccines are discussed, including nonviable protein and glycoprotein vaccines, pure polysaccharide vaccines, polysaccharide-protein conjugate vaccines, and live agent vaccines. Diagnostic and therapeutic applications of vaccine antibody measurement are discussed in depth. Important adverse effects of vaccines are also presented.

Background: The introduction of the vaccination against SARS-CoV-2 infection creates the need for precise tools for the quality control of vaccination procedures, detection of poor humoral response, and estimation of the achieved protection against the disease. Thus, the study aimed to compare the results of the anti-SARS-CoV-2 tests to evaluate the application of the WHO standard unitage (the binding antibody units, BAU/mL) for a measurement of response to the vaccination. Methods: Patients undergoing vaccination against SARS-CoV-2 with Pfizer/BioNTech BNT162b2 (BNT162b2) (n = 79), referred for SARS-CoV-2 antibody measurement prior to vaccination and 21 days after dose 1, and 8, 14, and 30 days after dose 2 were included. The sera were tested with three assays: Elecsys SARS-CoV-2 S (Roche), LIAISON® SARS-CoV-2 TrimericS IgG (DiaSorin), and SARS-CoV-2 IgG II Quant (Abbott). Results: The three assays showed varying correlations at different time points in the study. The overall agreement for all samples was moderate to high (ρ = 0.663–0.902). We observed the most uniform agreement for the day of dose 2 (ρ = 0.775–0.825), while it was least consistent for day 8 (ρ = −0.131–0.693) and 14 (ρ = −0.247–0.603) after dose 2. The dynamics of changes of the SARS-CoV-2 antibody levels in patients without history of prior SARS-CoV-2 infection appears homogenous based on the Roche results, more heterogenous when considering the DiaSorin results, and in between for the Abbott results. Conclusions: The results highlight the need for further work on the international standard of measurement of SARS-CoV-2 Ig, especially in the era of vaccination. The serological assays can be useful to detect IgG/IgM antibodies to assess the response to the vaccination. However, they cannot be used interchangeably. In terms of the evaluation of the immune response to the BNT162b2 vaccine, Roche and Abbott kits appear to be more useful.

Serological tests play important roles in the fight against the Coronavirus Disease 2019 (COVID-19). The most commonly used methods, enzyme-linked immunosorbent assays (ELISA), provide reliable and sensitive antibody measurement though they require bulky laboratory infrastructure as well as lengthy turnaround time. Conversely, lateral flow immunoassays (LFIA) are suitable for rapid point-of-care tests but with limited sensitivity. To combine the best attributes of ELISA and LFIA, we developed a novel streamlined immuno-PCR assay and applied it to a portable magnetofluidic instrument for point-of-care serological tests. In testing 107 clinical samples, our point-of-care serological test showed 98.3% (58/59) specificity and 93.8% (45/48) agreement with benchtop immunoassays. Moreover, 100% agreement was achieved by only slightly increasing the total assay time to 45 min, demonstrating its potential as a new point-of-care serological test for COVID-19 and beyond.

PurposeIn a country-wide seroprevalence study of COVID-19 in Estonia we aimed to determine the seroprevalence and the dynamics of IgG against SARS-CoV-2 after vaccination or positive PCR-test.MethodsLeftover blood samples were selected between February 8 to March 25, 2021, by SYNLAB Estonia from all counties and age groups (0-9, 10-19, 20-59, 60-69, 70-79, 80-100 years) proportionally to the whole Estonian population and tested for IgG against SARS-CoV-2 spike protein receptor-binding domain (anti-S-RBD IgG) using Abbott SARS-CoV-2 IgG II Quant assay. Antibody levels after positive PCR-test or vaccination were described by nonlinear model.ResultsA total of 2517 samples were tested. Overall seroprevalence (95% CI) was 20.1% (18.5-21.7%), similar in all age groups. If all individuals vaccinated with the first dose at least 14 days before antibody measurement were assumed to be seronegative, the overall seroprevalence was 15.8% (14.4-17.3%), 4-fold larger than the proportion of confirmed COVID-19 cases. According to nonlinear models, age increased anti-S-RBD IgG production after positive PCR-test but decreased after vaccination. The peak of anti-S-RBD IgG in a 52-year-old (median age of PCR-positive and/or vaccinated individuals) was significantly higher after vaccination compared with positive PCR-test (22082 (12897…26875) vs 6732 (2321…8243) AU/mL), but half-life was similar (26.5 (6.9…46.1) vs 38.3 (8.2…68.5) days).ConclusionOne year after the start of COVID-19 pandemic the actual prevalence of infection is still underestimated compared with confirmed COVID-19 cases, underlining the importance of seroepidemiological studies. Older individuals have lower anti-S-RBD IgG level after vaccination, but similar decline rate to younger.

The SARS-CoV-2 mRNA vaccine BNT162b2 (Pfizer-BioNTech) has become a game-changer in the COVID-19 crisis. Faster and wider coverage of vaccine supply is urgently needed, although vaccine supply is far from abundant in many countries and regions. There is no denying that Japan is vaccinating at a slower pace than in many other countries. At the end of April 2021, it had administered less than 2% of the population, according to the statistics website Our World in Data.1 Single-dose vaccination may be considered to induce an adequate antibody response in individuals with prior infection,2–5 which can lead to more effective vaccine distribution to people in serious need. However, multiple antibody responses in populations with various backgrounds, including prior COVID-19 infection, underlying diseases, and age, have not been investigated sufficiently. Due to the lack of antibody measurement data, antibody follow-up measurement recommendations have yet to be suggested. Accumulation of available data regarding quantitative antibody titer will lead to the establishment of personally customized schedules, including antibody follow-up, and will balance both faster delivery of vaccines and confirmation of effective vaccination.

BackgroundIncreasingly, vaccine efficacy studies are being recommended in low-and-middle-income countries (LMIC), yet often facilities are unavailable to take and store infant blood samples correctly. Dried blood spots (DBS), are useful for collecting blood from infants for diagnostic purposes, especially in low-income settings, as the amount of blood required is miniscule and no refrigeration is required. Little is known about their utility for antibody studies in children. This systematic review aims to investigate the correlation of antibody concentrations against infectious diseases in DBS in comparison to serum or plasma samples that might inform their use in vaccine clinical trials.Methods and findingsWe searched MEDLINE, Embase and the Cochrane library for relevant studies between January 1990 to October 2020 with no language restriction, using PRISMA guidelines, investigating the correlation between antibody concentrations in DBS and serum or plasma samples, and the effect of storage temperature on DBS diagnostic performance.We included 40 studies in this systematic review. The antibody concentration in DBS and serum/plasma samples reported a good pooled correlation, (r2= 0.86 (ranged 0.43 to 1.00)). Ten studies described a decline of antibody after 28 days at room temperature compared to optimal storage at -20°C, where antibodies were stable for up to 200 days. There were only five studies of anti-bacterial antibodies.ConclusionsThere is a good correlation between antibody concentrations in DBS and serum/plasma samples, supporting the wider use of DBS in vaccine and sero-epidemiological studies, but there is limited data on anti-bacterial antibodies. The correct storage of DBS is critical and may be a consideration for longer term storage.

BackgroundReliable high-throughput serological assays for SARS-CoV-2 antibodies (Abs) are urgently needed for the effective containment of the COVID-19 pandemic, as it is of crucial importance to understand the strength and duration of immunity after infection, and to make informed decisions concerning the activation or discontinuation of physical distancing restrictions.MethodsIn 184 serum samples from 130 COVID-19 patients and 54 SARS-CoV-2 negative subjects, the analytical and clinical performances of four commercially available chemiluminescent assays (Abbott SARS-Cov-2 IgG, Roche Elecsys anti-SARS-CoV-2, Ortho SARS-CoV-2 total and IgG) and one enzyme-linked immunosorbent assay (Diesse ENZY-WELL SARS-CoV-2 IgG) were evaluated and compared with the neutralization activity achieved using the plaque reduction neutralization test (PRNT).FindingsPrecision results ranged from 0.9% to 11.8% for all assays. Elecsys anti-SARS-CoV-2 demonstrated linearity of results at concentrations within the cut-off value. Overall, sensitivity ranged from 78.5 to 87.8%, and specificity, from 97.6 to 100%. On limiting the analysis to samples collected 12 days after onset of symptoms, the sensitivity of all assays increased, the highest value (95.2%) being obtained with VITRO Anti-SARS-CoV-2 Total and Architect SARS-CoV-2 IgG. The strongest PRNT50 correlation with antibody levels was obtained with ENZY-Well SARS-CoV-2 IgG (rho = 0.541, p < 0.001).InterpretationThe results confirmed that all immunoassays had an excellent specificity, whereas sensitivity varied across immunoassays, depending strongly on the time interval between symptoms onset and sample collection. Further studies should be conducted to achieve a stronger correlation between antibody measurement and PRNT50 in order to obtain useful information for providing effective passive antibody therapy, and developing a vaccine against the SARS-CoV-2 virus.

To identify viral pathogens in patients with secondary glaucoma associated with anterior segment uveitis and compare metagenomic deep sequencing (MDS) with enzyme-linked immunosorbent assay (ELISA) combined with Witmer-Desmonts coefficient (WDC) evaluation and real-time quantitative polymerase chain reaction (qPCR) on investigating pathogens in aqueous humor.Aqueous humor from 31 patients, including 22 Posner-Schlossman Syndrome and 9 other anterior uveitis, was assessed pathogens by ELISA combined with WDC evaluation, virus deoxyribonucleic acid (DNA) detection by real-time qPCR and MDS.Viral pathogens (HCMV or VZV or RV) were detected in 19 out of 31 eyes (61.3%) by real-time qPCR or WDC evaluation. MDS revealed the presence of HCMV DNA sequences in three PSS patients.Virus is an important pathogen in secondary glaucoma associated with anterior segment uveitis. MDS is a potential etiologic diagnosis tool to seek intraocular viral pathogens for secondary glaucoma associated anterior segment uveitis.

Serology tests are extremely useful for assessing whether a person has been infected with a pathogen. Since the onset of the COVID-19 pandemic, measurement of anti-SARS-CoV-2-specific antibodies has been considered an essential tool in identifying seropositive individuals and thereby understanding the extent of transmission in communities. The Luminex system is a bead-based technology that has the capacity to assess multiple antigens simultaneously using very low sample volumes and is ideal for high-throughput studies. We have adapted this technology to develop a COVID-19 multi-antigen serological assay. This protocol described here carefully outlines recommended steps to optimize and establish this method for COVID-19-specific antibody measurement in plasma and in saliva. However, the protocol can easily be customized and thus the assay is broadly applicable to measure antibodies to other pathogens.

The optimum titers play a pivotal role for the success of CPT;in the ICMR study, they have only mentioned that the titers were detectable but the percentage is high, moderate and low titers has not been mentioned. On the question of neutralising antibody titers, IgG titers are typically associated with the severity of disease and decline in the early convalescent phase in less severe forms of the disease. In the PLACID trial, most of the donors (94.2%) had mild disease. Moreover, the fact that antibody titers were not measured in CP before transfusion, due to lack of validated and reliable commercial tests for qualitative or quantitative antibody measurement, could be another key confounding factor. The heterogeneity of the PLACID trial across its 39 study sites, especially in the severity of disease of enrolled participants, estimation of nAB (timing and method), and the "Standard of Care," could impinge on the reliability of the study data. Further, in the ICMR study, 67.9% of CPT group are PCR negative by day 7 when compared to 54.6% of non-CPT. This perhaps can be considered as beneficial impact of CPT which helps in decreasing community transmission. This data can also be used to tighten the discharge criteria to enable faster discharges, thus improving the availability of beds for a worsening pandemic. Notably, the dosage of CP administered is also variable. Some trials are administering doses as high as 600 ml, in single infusions or divided doses, up to five transfusion sessions. The consensus about effective CP dose is yet to be elucidated.

Understanding of the determinants of immunogenicity, the testing paradigm, the impact of antibody attributes on clinical outcomes and regulatory guidance is leading to harmonized practices for immunogenicity assessment of biotherapeutics. However, generation of robust immunogenicity data for inclusion in product labels to support clinical practice continues to be a challenge. Assays, protocols and antibody positive controls/standards need to be developed in sufficient time to allow assessment of clinical immunogenicity using validated methods and optimized protocols. Standardization and harmonization play a significant role in achieving acceptable results. Harmonization in the postapproval setting is crucial for a valid interpretation of the product's immunogenicity and its clinical effects. Efforts are ongoing to standardize assays where possible for antibody measurement and for measuring product/drug levels by producing reference standards. Provision of such standards will help toward personalized treatment strategies with better patient outcomes.

Background and Objectives: In Caucasians, fetal/neonatal alloimmune thrombocytopenia (FNAIT) is most commonly due to maternal HPA-1a antibodies. HPA-1a typing followed by screening for anti-HPA-1a antibodies in HPA-1bb women may identify first pregnancies at risk. Our goal was to review results from previous published studies to examine whether the maternal antibody level to HPA-1a could be used to identify high-risk pregnancies. Materials and Methods: The studies included were categorized by recruitment strategies: screening of unselected pregnancies or samples analyzed from known or suspected FNAIT patients. Results: Three prospective studies reported results from screening programmes, and 10 retrospective studies focused on suspected cases of FNAIT. In 8 studies samples for antibody measurement, performed by the monoclonal antibody immobilization of platelet antigen (MAIPA) assay, and samples for determining fetal/neonatal platelet count were collected simultaneously. In these 8 studies, the maternal antibody level correlated with the risk of severe thrombocytopenia. The prospective studies reported high negative predictive values (88–95%), which would allow for the use of maternal anti-HPA-1a antibody level as a predictive tool in a screening setting, in order to identify cases at low risk for FNAIT. However, due to low positive predictive values reported in prospective as well as retrospective studies (54–97%), the maternal antibody level is less suited for the final diagnosis and for guiding antenatal treatment. Conclusion: HPA-1a antibody level has the potential to predict the severity of FNAIT. (Less)

The transplanted liver appears resistant to antibody-mediated injury compared to other transplanted organs such as kidney or heart. However, a growing number of reports suggest that alloantibody to the liver is associated with poorer outcomes. The data surrounding this field are unclear, and their interpretation remains controversial. Mechanistically, there is not a clear explanation for the liver's resistance to antibody-mediated injury, and the pathological criteria for antibody-mediated rejection (AMR) remain ill-defined. Furthermore, treatment of AMR is non-uniform. The field would benefit from better outcome data based on measurement of antibody at the time of transplantation and at the time of rejection. Consensus opinion regarding antibody and the liver might emerge with better standardization of antibody measurement and pathological definition of AMR.

International standards for anti-beta2 glycoprotein I (anti-β2GPI) testing are needed. We evaluated the suitability of polyclonal/monoclonal candidate reference materials (RM) for the assay. IgG/IgM anti-β2GPI were affinity-purified (AP) from high-positive antiphospholipid syndrome sera and IgG from HCAL clone supernatant. Igs were tested for purity by SDS-PAGE, pooled, concentrated, sterile-filtered and the protein concentration determined. One unit was defined as the binding activity of 1 µg/ml of AP anti-β2GPI Ig. IgG/IgM RM were each assigned a unit value using the respective AP material as a calibrator. Polyclonal/monoclonal RM and 30 samples were evaluated for linearity, unit equivalency and commutability. Polyclonal AP material was assigned a value of 100 U IgG and 15 U IgM anti-β2GPI, respectively. IgG-RM had a value of 270 IgG and the IgM-RM of 220.3 IgM anti-β2GPI U. The linearity ( R2) of each RM curve for the various assays ranged from 0.96 to 0.99. Commutability samples fit very well within 95% prediction intervals and had excellent correlation when comparing assays. IgG and IgM polyclonal and IgG monoclonal RM displayed excellent linearity and commutability, being good candidates for better standardization of anti-β2GPI immunoassays.

Celiac disease (CD) is a common illness, affecting 0.5–1% of the population. Its classic presentation consists of gastrointestinal symptoms, however, many extra-intestinal symptoms and some associated diseases have been studied. Pediatricians should know the typical and atypical presentations of CD and how to diagnosis and treat its complications. The aim of this study was describe what pediatricians in Brazil know about CD. A descriptive, cross-sectional study with pediatricians who participated in the Nestle Pediatrics Course, in the city of Natal, Brazil, in 2008. They were asked to complete a self-applicable questionnaire covering aspects concerning the prevalence, diagnosis, and treatment of CD and the conditions associated with this disease. A total of 632 pediatricians completed the questionnaire. The majority of respondents (82.9%) were female. All the geographical regions of Brazil were represented. More than 65% of respondents had undergone specialist training in pediatrics, and 40% of respondents had worked as pediatricians for more than 25 years. Only 22% replied that celiac disease may be asymptomatic, 57% stated that antigliadin antibody measurement represents the best screening tool for the disease, and two-thirds replied that bowel biopsy would be the most indicated method. The pathologies and conditions associated with celiac disease were identified by fewer than 50% of respondents. Exclusion of gluten from the patient’s diet was mentioned as the treatment for celiac disease by 86.4% of the pediatricians. We conclude that pediatricians have superficial information about CD. The need for relevant information on celiac disease is fundamental and is recognized by the pediatricians themselves.

During the last 25 years clinical autoantibody determinations have changed dramatically. Old and slow techniques with high diagnostic specificity have been replaced with automated and faster techniques that most often have a higher diagnostic sensitivity at the expense of a lower diagnostic specificity. Newer techniques are mostly quantitative, allowing for follow-up of autoantibody levels. Whereas the older procedures utilized autoantigens in soluble and native states, most modern techniques rely on autoantigens attached to surfaces, with the risk of exposure of denatured epitopes. Comparisons between antibody measurement techniques can be obtained from the results of external quality assessment programs. Yet as the main objective for external quality assessment is the monitoring of clinical laboratories they cannot focus on the kind of low-level and often polyreactive sera which are common in the real world and in which a single definite target response cannot be easily defined. Such common sera are very useful, however, for analysis of differences between autoantibody measurement techniques. The European Consensus Finding Study Group on Autoantibodies has been working with this approach for 28 years.

Background: Thyroglobulin (Tg) measurements are complicated by interference from Tg autoantibodies (TgAbs) or heterophilic antibodies (HAMAs). We used a new automated immunochemiluminometric assay (ICMA) with Tg recovery (TgR) on the Nichols Advantage® platform to reassess the clinical utility of recovery testing in detecting interference in serum Tg measurement in patients with differentiated thyroid carcinoma. Methods: We used 2 TgAb methods to detect Tg measurement interference with TgR and quantitative TgAb measurement in sera from 127 patients. In a limited number of samples, we used an RIA as comparison method because it appeared to be minimally affected by TgAb. Results: Prevalence of TgAbs was 13% (17 of 127) in either 1 or both TgAb assays. A compromised TgR ( Conclusions: The Nichols Advantage TgR assay is a valuable complementary method to overcome the technical problem of interference by TgAbs or HAMAs in TgAb assays. Further studies are needed to confirm the potential added value of this TgR assay.

RIBAテストIII; NS5抗体の有無を，ALT正常，HCVセロタイプI型のRNA陽性者31例について測定し，平均3年間追跡検討した。その結果，NS5抗体(-)は22例，NS5抗体(4+)が9例で，これは対照とした40IU/l＜ALT＜100IU/lC型非活動性慢性肝炎25例のNS5抗体(-)3例，NS5抗体(4+)22例の結果とχ2検定で有意の差があった。累積ALT正常値維持率について，NS5抗体(-)であった22例と，NS5(4+)であった9例を，Kaplan-Meier法で検討すると，Log-rank検定で，NS5抗体(-)群が有意に高率であった。従ってRIBAテストIII; NS5抗体陰性無症候性HCVキャリアの臨床的マーカーになり得ると考えられた。

Syphilis has re-emerged in the United States and elsewhere, and clinicians caring for HIV-infected patients are challenged with syphilis diagnosis and management decisions. HIV alters the natural history of syphilis to an extent that is poorly understood, and initial presentation may be more varied in coinfected patients. Although commonly available diagnostic assays for syphilis should be interpreted as usual, such tests rely on antibody measurement and may be an imperfect indicator of active infection. Assessment of all available clinical and risk behavior data remains critically important in the diagnosis of syphilis in coinfected patients. Treatment of syphilis in such patients requires stage-appropriate therapy, with careful serologic monitoring to assess response. Clinicians must have heightened appreciation of the role of frequent risk assessment, serologic screening, symptom recognition, and follow-up of treated patients, as well as an understanding of public health functions such as sex partner treatment and communicable disease reporting.

To study preventive strategies, it is essential to screen pregnant women having group B Streptococcus (GBS) infection in the birth canal. For the purpose of studying preventive measures against this infection, nationwide multicenter research was performed in GBS-carrying pregnant women. Of a total of 10 267 pregnant women, 1860 cases (18.1%) had GBS. The most common serotypes of detected GBS were type NT6 and JM9, followed by type III, type Ia and then type Ib. Type-specific antibody titer was below the cut-off point of 10 units/mL in 30.9% of Ia carriers, 58.5% of Ib carriers, 45.9% of II carriers and 32.9% of III carriers. Fortunately, no neonatal GBS infection occurred during this research. We concluded that 18.1% of studied pregnant women were GBS carriers and one-third of these GBS carriers required preventive procedures with antibody measurement.

Purposes Recently, the serum p53 antibody (S-p53Ab) has been used widely in clinical practice as a tumor marker for colorectal cancer (CRC). However, no large-scale studies have examined the usefulness of serial measurements of S-p53Ab or have established the relationship of this parameter with the clinicopathological factors of CRC. Methods An ELISA for S-p53Ab was performed for 1384 primary CRC patients, and the results were categorized by the clinicopathological factors. Results The S-p53Ab positivity rate was 24.1 %, and was significantly higher in Stage III‐IV than in Stage 0‐II cases. However, no relationship was seen with the serum carcinoembryonic antigen (CEA) or carbohydrate antigen 19-9 (CA19-9) levels. The addition of the S-p53Ab assay to the CEA and CA19-9 measurements increased the overall diagnostic sensitivity to 50.9 % (CEA and/or CA19-9: 37.3 %). In patients who had undergone complete resection, S-p53Ab positivity was associated with a decrease in the relapse-free survival (p = 0.012), but it was not independent prognostic indicator. S-p53Ab positivity had no influence on the cancer-specific survival. Conclusions The S-p53Ab positivity rate was higher than the positivity rates for CEA and/or CA19-9 in Stage 0‐I CRC patients. Combining the use of the three tumor marker tests is a potentially effective method for detecting even early-stage CRC.

Background. Recent diagnostic imaging tests contribute to improving the diagnosis of pancreatobiliary cancers. However, it is not practical to perform these tests for all patients as screening. Thus, less-invasive and simple screening tests are still required. A method to detect the IgG antibody induced in serum against the p53 protein accumulating due to p53 gene mutation, as a biomarker, was developed around 1990.Method. 35 patients with pancreatic cancer, 12 patients with biliary tract cancer, and 31 patients with benign pancreatobiliary diseases were entered into this study. Measurement of serum anti-p53 antibody was conducted in all patients. In addition, the rate of p53 protein overexpression was examined in those cases that could be examined pathologically.Result. Among all patients in the pancreatic cancer and biliary tract cancer groups, there was no patient with serum anti-p53 antibody positive value that exceeded the standard value. The rate of p53 protein overexpression was 48.0% in the patients with pancreatobiliary cancers and 0% in the benign pancreatobiliary diseases group.Conclusion. Serum anti-p53 antibody measurement does not contribute to the diagnosis of pancreatobiliary cancers. Instead, traditional p53 immunostaining still appears to be valuable in combination with standard procedures.

The measurement of antibodies in the external secretions that bathe mucosal surfaces is important in understanding the host response to the opportunistic pathogen, Candida albicans and its determinants of pathogenesis at these sites. The principal immunoglobulin isotype in mucosal secretions is secretory immunoglobulin A (SIgA). Unlike the circulatory system, mucosal surfaces are open systems in which the concentrations of immune factors are affected by diurnal variation, changes in flow rate, complex formation with mucins, and other variables. Thus, it is necessary to control these factors if meaningful data are to be obtained. This chapter outlines methods for the measurement of anti-Candida SIgA antibodies in primary units and shows how to control the factors that influence antibody measurement in external secretions.

Penicillins are effective for treating bacterial infections in many clinical situations, but in certain cases, they cause allergic reactions varying from mild skin rashes to anaphylactic shock and death. These symptoms often resemble those seen in immediate or delayed hypersensitivity reactions, and may be associated with drug specific IgE and/or drug specific T cells. Currently, the laboratory tests include isotope based serum IgE antibody measurement as well as skin test. However, radioisotope allergen specific tests (RAST) are not convenient, and the standardized skin-testing reagents and protocol do not usually exist. In fact, the skin test is often avoided because of the high risks. Therefore, in the current study, we have developed a non-isotope based penicillin-reactive IgE screening platform with high sensitivity and specificity. Using this screening platform to detect IgE of a mouse model sensitized with penicillin reveals that high levels of penicillin specific IgE were found in the penicillin sensitized animals but not in OVA sensitized or untreated control animals. Penicillin specific T cells produce relatively higher levels of IL-4 and IL-5 in the penicillin sensitized group, indicating a Th2-cytokine dominated response of T-cell dependent IgE production against penicillin. This observation and the development of such convenient platform to measure penicillin specific IgE may benefit further study of penicillin allergy.

Ultrasonography (USG) is frequently used to diagnose thyroiditis. The accuracy of this diagnosis, however, is unclear. This study was performed to determine the sensitivity and specificity of USG in detecting thyroiditis. Three hundred thyroid patients were enrolled in the study. The diagnosis of thyroiditis by USG and by antithyroid peroxidase (anti-TPO) antibodies was compared. Thyroiditis was determined in 75 of 300 thyroid patients by USG and in 180 of 300 patients by anti-TPO antibody measurement. Anti-TPO antibody was positive in 84.2% of the cases who were diagnosed by USG. This, compared with diagnosis by anti-TPO, USG had high specificity (90%) but low sensitivity (35%) for the diagnosis of thyroiditis. Thus, USG does not appear to be an efficient screening test for thyroiditis, but patients diagnosed are likely to have the disorder.

Aims Anti-dsDNA antibody measurement by radioimmunoassay has traditionally had better performance characteristics for the diagnosis of systemic lupus erythematosus (SLE) than ELISA methods. However, a new anti-dsDNA ELISAin which the dsDNA is attached to the plate by nucleosomes (dsDNA-NcX) has recently been reported to be equivalent. This study is a case-control validation comparing the two assays. Methods Consecutive samples sent for anti-dsDNA testing were measured by the Farr radioimmunoassay (Amerlex) and the anti-dsDNA-NcX ELISA (Euroimmun). Performance characteristics and correlation with disease activity were assessed. Results There were 26 patients with SLE and 26 controls with no connective tissue disease. The sensitivity and specificity for the Farr was 85% and 85% versus 77% and 96%, respectively, for the ELISA. There was no statistical difference between these results. The ELISA showed a better correlation with disease activity. Conclusion Our preliminary data also suggest that the performance of the Anti-dsDNA-NcX ELISA is comparable to the Farr radioimmunoassay, with lower sensitivity but better specificity at the manufacturer cut-offs. Correlation with disease activity appears to be better by ELISA. Further evaluations on a larger sample size are now to be performed.

A turkey red blood cell haemagglutination assay (TRBC HA) allowing rapid measurement of the antibodies against tetanus has been set recently. Its feasibility was evaluated in injured patients admitted into an emergency unit during summer 1987. TRBC HA was performed by the same physician who questioned the patient on his/her previous vaccinations and evaluated his/her immunization status. The rapid HA test practiced in emergency was controlled by TRBC HA and ELISA measurement of antibodies carried out in the laboratory. Each method was compared to the others : the results were fitted and no significant difference was found. The preventive procedures which would have followed the antibody measurement by immediate TRBC HA were compared to the decision resulting from clinical evaluation. The immunoprophylactic attitude would have been the same in 82% of cases. TRBC HA is a reliable test, and feasible in an emergency: it could help in making the appropriate decision for immunoprophylaxis to be applied to the injured and other patients at risk of tetanus.

The presence of spermagglutinating antibodies in blood and semen has been associated with reducedfertility in men. In this study 203 men were screened for infertility. An antibody measurement was performed on the blood and semen of each patient. Each semen specimen was also examined for spontaneous agglutination. Twelve patients with a positive reaction in the blood underwent a sperm-cervical mucus contact test. We have attempted to correlate the findings in blood with the observed functional results in semen and cervical mucus. We believe that these simple tests should be included in the infertility work-up in order to determine the presence of immune infertility.

A binding function was used to characterize the dose-response curves in an enzyme-linked immunosorbent assay (ELISA) for rabbit anti -hapten IgG antibodies. This curve-fitting procedure gave absorbances which deviated about 10% from the experimental absorbances. The method enables one to estimate antibody quality and quantity in large scale antibody measurement.

SUMMARY It was found possible to correlate serological responses to porcine parvovirus (PPV) with the time after infection. Two procedures were used for PPV antibody measurement: an immunodiffusion technique to measure precipitating antibody and a haemagglutination inhibition (Hl) procedure to measure concentration of 2-mercaptoethanol (2-ME) sensitive antibody. Both procedures successfully related antibody titres to time post-infection, but it was considered that a 2 M 2-ME HI procedure showed the greater promise for field investigations.

In an ELISA for antitoxoplasma IgG (antigen-coated polystyrene beads, horseradish peroxidase-coupled IgG or staphylococcal protein A), 3 modes of expressing the analytical results were considered, i.e., end-point antibody titre, untransformed absorbance reading at a single sample dilution, and antibody-activity unit from a calibration response curve (reference sera as calibrators). Criteria of merit for evaluation were defined as (a) stability of data under various conditions relating to both changes in assay design and minor variability of experimental conditions, and (b) linearity of response with dilutions of positive sera in negative serum, i.e., with positive sera sequentially defined as to antibody activity. Conclusions emerging were: single absorbance readings have some validity as indicators of trends but are very prone to systematic and random variability and inconsistent in response-antibody activity parallelism; parallelism of response proved to be an advantage of titration, but disadvantages are lack of practicability (manipulation and reagent costs involved) and lack of reliability (high levels of systematic and statistical error). The introduction of a reference scale allowing data to be expressed in activity units eliminates systematic components of error and gives analytical consistency. Use of the latter appears mandatory for between-run, between-laboratory and between-method normalization.

Serum and cerebrospinal fluid (CSF) IgM were measured in 182 patients at various stages of Gambian sleeping sickness and correlated with antibody levels measured by enzyme-linked immunosorbent assay (ELISA). Each of these tests in serum gave a 30% false negative result, but when both were used this fell to 12%. Measurements of IgM in CSF were raised in 87% of patients with advanced disease and in none of the early cases. The IgM levels fell slowly to normal by 12 months after treatment. A high level at this time, or a rise after treatment, was helpful in diagnosing relapsed patients. Antibody levels in CSF were of no use in diagnosis or prognosis, and were raised in many controls.

Introduction: Multiplex-antibody detection has been recently proposed for the noninvasive diagnosis of staphylococcal prosthetic joint infection (PJI). We evaluated this approach for the post-treatment follow-up of patients.Methods: Nineteen cases of staphylococcal PJI were prospectively followed for one year after treatment. The IgG response against eight staphylococcal antigens was measured before surgery and one year post-surgery using Luminex technology (Austin, TX, USA); median fluorescence intensity values determined for each antigen were transformed into a “Total Response Index” (TRI).Results: Patients (11 women/8 men) had a mean (SD) age of 72.2 (12.4) years. Site of prosthesis was the knee (n=10), the hip (n=8) and the shoulder (n=1). Ten patients were infected by S. epidermidis, six by S. aureus, and three by S. lugdunensis. TRI values at one year were significantly lower than pre-surgery values (mean [SD]: 5.9 [1.8] versus 8.1 [3.4], p=0.02) and decreased, on average, by 21.2%. TRI values markedly increased in two patients. One patient had a relapse of S. aureus PJI at five months post-surgery, with a 37% increase of the TRI. The other had septic failure three months after revision for S. lugdunensis PJI; all intraoperative samples remained culture-negative, but the TRI increased by 51% and the antibody profile showed a marked change, suggesting a reinfection with another staphylococcal species.Conclusion: Multiplex-antibody measurement may be useful for the follow-up of staphylococcal PJI and may help to detect septic failure involving organisms targeted by the assay.