scholarly journals Comparative evaluation of three commercial Toxoplasma-specific IgG antibody avidity tests and significance in different clinical settings

2009 ◽  
Vol 58 (3) ◽  
pp. 358-364 ◽  
Author(s):  
Branko Bobić ◽  
Ivana Klun ◽  
Marija Vujanić ◽  
Aleksandra Nikolić ◽  
Vladimir Ivović ◽  
...  
Keyword(s):  
Clinical Settings ◽  
Igg Antibody ◽  
Perfect Agreement ◽  
Igg Avidity ◽  
Resource Limited ◽  
Specific Igg ◽  
Set Up ◽  
Kinetics Of

Determination of the avidity of specific IgG antibodies has become a generally accepted diagnostic aid for dating Toxoplasma infection. In this study, the Labsystems, VIDAS and EUROIMMUN Toxoplasma IgG avidity assays were compared on a series of 133 Toxoplasma IgG- and IgM-positive sera from symptomatic patients (n=28), from pregnant (n=43) and non-pregnant (n=26) women, and on 18 IgG-positive and IgM-negative sera from chronically infected patients. The results showed excellent concordance between the Labsystems and VIDAS tests in both the IgM-positive (r=0.82, κ=0.771) and IgM-negative (κ=0.609) sera, whilst the agreement of the EUROIMMUN assay with both the Labsystems and VIDAS tests in the IgM-positive sera was moderate (κ=0.575 and κ=0.525, respectively) and in the IgM-negative sera was poor (κ=0.000). Analysis of the kinetics of the maturation of avidity in 13 patients in whom follow-up sera were available showed that, despite a general trend of maturation, in two patients the avidity did not become high during 6 and 11 months of follow-up. In view of the clinical setting, in the symptomatic patients, despite one case of complete discrepancy and five cases of partial discrepancy, the Labsystems and VIDAS tests were in almost perfect agreement (κ=0.812), whilst the agreement in pregnant and non-pregnant women was substantial (κ=0.754 and κ=0.708, respectively). In conclusion, the Labsystems and VIDAS tests are equally reliable for the measurement of Toxoplasma IgG avidity; the choice of test should depend on the laboratory set-up. The EUROIMMUN test may be an acceptable alternative in resource-limited settings, but should be used prudently.

Evaluation of number of target lesions to analyze in time to progression by RECIST

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 6549-6549
Author(s):  
M. Gonen ◽  
L. Schwartz ◽  
R. Ford
Keyword(s):  
Response Assessment ◽  
Optimal Number ◽  
Response To Therapy ◽  
Phase Iii ◽  
Time To Progression ◽  
Overall Response ◽  
Considerable Controversy ◽  
Set Up

6549 Background: RECIST criteria were designed to evaluated tumor shrinkage and response to therapy by measurement of multiple target lesions, evaluation of non target and new lesions. There is considerable controversy surrounding the optimal number of lesions to assess response, with RECIST requiring the measurement of up to 10 target lesions. These guidelines were set up to evaluate the endpoint of best overall response. Increasingly, time to progression has become an important endpoint in oncology trials. We evaluated the optimal number of lesions to measure to accurately and reproducibly assess time to progression. Methods: We evaluated target lesions metastases in 105 patients enrolled on a Phase III clinical trial. All patients underwent CT at baseline and standard follow up scans until progression. Target lesions were measured unidimensionally and response was assessed according to RECIST by 2 independent Radiologists. A total of 519 target lesions were assessed. Response was calculated according to the rules of target lesions (up to 10) by RECIST, utilizing the 2 largest lesions and randomly selecting 2 target lesions. Results: Using the 2 largest lesions, time to progression was concordant in 83% of cases. The 2 Radiologists determined the two same largest lesions in 89% of cases. Since the determination of the largest or the same target lesions is not always possible or performed, a random selection of 2 target lesions demonstrated a 76% concordance in the time to progression. Conclusions: Measurement of time to progression may have a greater degree of variability than measurement of best overall response and therefore measurement of minimal selected lesions will lead to a great variability in response assessment. No significant financial relationships to disclose.

scholarly journals Development of a Rapid and Convenient Method for Determination of Rubella Virus-Specific Immunoglobulin G Avidity

2007 ◽  
Vol 14 (11) ◽  
pp. 1416-1419 ◽  
Author(s):  
Christelle Vauloup-Fellous ◽  
Jessica Ursulet-Diser ◽  
Liliane Grangeot-Keros
Keyword(s):  
Immunoglobulin G ◽  
Rubella Virus ◽  
Primary Infection ◽  
Virus Infections ◽  
Serum Samples ◽  
Igg Avidity ◽  
Specific Immunoglobulin ◽  
Specific Igg ◽  
Semiautomated Method

ABSTRACT We describe here a rapid and semiautomated method for the determination of rubella virus immunoglobulin G (IgG) avidity with the VIDAS instrument. A total of 153 serum samples from persons with naturally acquired rubella virus infections (n = 98), from vaccinated persons (n = 44), and from patients with autoantibodies (n = 11) were included in this study. The rubella virus-specific IgG avidity assay we developed for the VIDAS instrument was evaluated by comparison with an in-house method. Results obtained with the VIDAS instrument allow considering this method valuable to help confirm or exclude acute primary infection or recent vaccination.

scholarly journals Diagnostic procedure for idiopathic eosinophilic pleural effusion: A single-center experience

2019 ◽  
Author(s):  
Weizhan Luo ◽  
Yunxiang Zeng ◽  
Panxiao Shen ◽  
Jianxing He ◽  
Jinlin Wang
Keyword(s):  
Pleural Effusion ◽  
Diagnostic Procedure ◽  
Clinical Work ◽  
Igg Antibody ◽  
Single Center Experience ◽  
Specific Igg ◽  
The Mean ◽  
Work Up ◽  
Eosinophilic Pleural Effusion

Abstract Background: Eosinophilic pleural effusion (EPE) is attributed to many known and obvious causes, but some patients remain idiopathic even after thorough clinical work-up. The present study aims to better characterize idiopathic EPE (IEPE) and to outline the diagnostic procedure for this disease. Methods: The complete clinical data of eleven prospectively collected consecutive patients with IEPE were analysed and preliminary diagnostic procedure of IEPE in our hospital was performed. Results: All the 11 patients had respiratory symptoms and unilateral pleural effusion (PE) occurred in 4 patients. The mean percentage of eosinophils in PE was 22.4% (range, 12.4%-50.5%). Lactate dehydrogenase, adenosine deaminase, protein and carcinoembryonic antigen in PE were 246.0 U/L (range, 89.8-421.9 U/L), 13.8 U/L (range, 1.8-24.0 U/L), 42.6 g/dl (range, 32.8-52.6 g/dl) and 2.17 mg/mL (range, 0.46-4.31 mg/mL), respectively. A parasite-specific IgG antibody in blood and parasite eggs in stool were negative. No evidence of tuberculosis or malignancy was observed in pleural biopsy. Symptoms and abnormal pulmonary imaging were eliminated after glucocorticoid use. Conclusions: IEPE is a diagnosis of exclusion. Patients with EPE without a clear cause should be asked for complete medical, surgical and drug-related history, and we recommend a thorough work-up and follow-up after the use of glucocorticoid until the effusion does not reappear.

scholarly journals Development and Use of an Endpoint Titration Assay To Characterize Mumps IgG Avidity following Measles, Mumps, and Rubella Vaccination and Wild-Type Mumps Infection

mSphere ◽  
2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Sara Mercader ◽  
Marcia McGrew ◽  
Sun B. Sowers ◽  
Nobia J. Williams ◽  
William J. Bellini ◽  
...  
Keyword(s):  
Virus Infection ◽  
Characteristic Curve ◽  
Vaccine Dose ◽  
The United States ◽  
Mumps Virus ◽  
Igg Antibody ◽  
Avidity Assay ◽  
Igg Avidity ◽  
Specific Igg ◽  
Avidity Maturation

ABSTRACTWaning mumps IgG antibody and incomplete IgG avidity maturation may increase susceptibility to mumps virus infection in some vaccinees. To measure mumps IgG avidity, serum specimens serially diluted to the endpoint were incubated on a commercial mumps-specific IgG enzyme immunoassay and treated with the protein denaturant diethylamine (60 mM, pH 10). End titer avidity indices (etAIs [percent ratio of detected diethylamine-resistant IgG at endpoint]) were calculated. Unpaired serum specimens (n= 108) from 15-month-old children living in a low-incidence setting were collected 1 month and 2 years after the first measles, mumps, and rubella vaccine dose (MMR1) and tested for mumps avidity. Per the receiver operating characteristic curve, the avidity assay is accurate (area under the curve, 0.994; 95% confidence interval [CI], 0.956 to 1.000), 96.5% sensitive (95% CI, 87.9 to 99.6%), and 92.2% specific (95% CI, 81.1 to 97.8%) at an etAI of 30%. When 9 sets of paired serum specimens collected 1 to 60 months post-MMR1 were tested for mumps and measles IgG avidity using comparable methods, the mumps etAI increased from 11% to 40 to 60% in 6 months. From 6 to 60 months, avidity was sustained at a mean etAI of 50% (95% CI, 46 to 54%), significantly lower (P  < 0.0001) than the mean measles etAI of 80% (95% CI, 74 to 86%). Mean etAIs in children 2 years post-MMR1 (n= 51), unvaccinated adults with distant mumps disease (n= 29), and confirmed mumps cases (n= 23) were 54, 62, and 57%, respectively. A mumps-specific endpoint avidity assay was developed and validated, and mumps avidity was determined to be generally sustained at etAIs of 40 to 60%, reaching etAIs of >80% in some individuals.IMPORTANCENumerous outbreaks of mumps have occurred in the United States among two-dose measles-mumps-rubella (MMR)-vaccinated populations since 2006. The avidity of mumps-specific IgG antibodies may affect susceptibility to mumps virus infection in some vaccinated individuals. To accurately measure mumps avidity, we developed and validated a mumps-specific IgG avidity assay that determines avidity at the endpoint titer of serially diluted serum specimens, providing results that are independent of IgG concentration. At low antibody titers, endpoint methods are considered more accurate than methods that determine avidity at a single dilution. We determined that 6 months after the first MMR dose, mumps IgG avidity is high and generally sustained at avidity indices of 40 to 60%, reaching values of >80% in some individuals. Additionally, 4% (4/103) of individuals had avidity indices of ≤30% (low avidity) 2 years after vaccination. Inadequate mumps avidity maturation may be one factor influencing susceptibility to mumps virus infection among previously vaccinated or naturally infected individuals.

scholarly journals Analytical evaluation of a new Microdisk™ technology-based multiplex HPV genotyping system – the QPLEX™ HPV genotyping kit

2019 ◽  
Vol 43 (4) ◽  
pp. 201-209
Author(s):  
Yong Kwan Lim ◽  
Oh Joo Kweon ◽  
Jee-Hye Choi ◽  
Seungman Park ◽  
Keumsim Jung ◽  
...  
Keyword(s):  
Analytical Performance ◽  
Comparison Study ◽  
Perfect Agreement ◽  
Hpv Genotyping ◽  
Precision Evaluation ◽  
Polymerase Chain ◽  
Interference Tests ◽  
Multiplex System

Abstract Background Recently, the QPLEX™ human papillomavirus (HPV) genotyping kit (QuantaMatrix, Seoul, Korea), a Microdisk™ technology-based multiplex system, was developed to detect 32 HPV genotypes. We evaluated the analytical performance of this kit by conducting a comparison study, precision evaluation and interference testing. Methods A total of 1594 cervical swab specimens were used to compare the QPLEX™ HPV genotyping kit with other commercially available kits (GeneFinder HPV Liquid Bead MicroArray Genotype polymerase chain reaction [PCR] kit, Infopia, Seoul, Korea; PANArray™ HPV Genotyping Chip, PANAGENE, Daejeon, Korea). For the determination of precision, we evaluated four types of precision profiles: repeatability, lot-to-lot variability, operator-to-operator variability and site-to-site variability. In addition, interference tests were performed with various interferents. Results The results of the QPLEX™ HPV genotyping kit showed almost perfect agreement with the other commercially available HPV genotyping assays. The combined precision was acceptable. In addition, there was no tested interferent that affected the results of the QPLEX™ HPV genotyping kit. Conclusions The QPLEX™ HPV genotyping kit showed acceptable analytical performance in our study. This assay could be a suitable option for HPV genotyping in routine and follow-up tests.

Re-evaluation of the VIDAS® cytomegalovirus (CMV) IgG avidity assay: Determination of new cut-off values based on the study of kinetics of CMV–IgG maturation

2013 ◽  
Vol 56 (2) ◽  
pp. 118-123 ◽  
Author(s):  
Christelle Vauloup-Fellous ◽  
Mario Berth ◽  
Fabienne Heskia ◽  
Jean-Marc Dugua ◽  
Liliane Grangeot-Keros
Keyword(s):  
Avidity Assay ◽  
Igg Avidity ◽  
Kinetics Of

scholarly journals Performance Evaluation of the Siemens SARS-CoV-2 Total Antibody and IgG Antibody Test

2021 ◽  
Author(s):  
Lisa Florin ◽  
Karel Maelegheer ◽  
Wouter Vandewal ◽  
Dirk Bernard ◽  
Johan Robbrecht
Keyword(s):  
Antibody Test ◽  
Control Group ◽  
Igg Antibody ◽  
Antibody Assays ◽  
Antibody Titers ◽  
Polymerase Chain ◽  
Kinetics Of ◽  
Antibody Tests ◽  
Positive Controls

Abstract Objective In this study, the performance of 2 commercially available SARS-CoV-2 antibody assays is evaluated. Methods The Siemens SARS-CoV-2 Total (COV2T) and IgG (COV2G) antibody tests were evaluated on a Siemens Atellica IM1300 analyzer. Imprecision was assessed with the CLSI EP15 protocol using positive controls. Ninety control group specimens were analyzed for specificity, and 175 specimens from 58 patients with polymerase chain reaction–confirmed SARS-CoV-2 were measured for the sensitivity and kinetics of the antibody response. Results Within-run and total imprecision were acceptable for both assays. Both tests showed a specificity of 100%. Sensitivity earlier in the disease state was greater for the COV2T assay than for the COV2G assay, but sensitivity &gt;14 days after onset of symptoms approached 100% for both. For all patients, antibody titers remained above the seroconversion cutoff for all follow-up specimens. Conclusion This study shows acceptable performance for both the Siemens COV2T and COV2G test, although seroconversion occurs earlier with the COV2T test.

scholarly journals Human IgG and IgA responses to COVID-19 mRNA vaccines

2021 ◽  
Author(s):  
Julian Campillo Luna ◽  
Adam V Wisnewski ◽  
Carrie A Redlich
Keyword(s):  
Vaccine Dose ◽  
Serum Levels ◽  
Rapid Decline ◽  
Natural Immunity ◽  
Limited Information ◽  
Viral Neutralization ◽  
Time To Peak ◽  
Specific Igg ◽  
Kinetics Of

SARS-CoV-2 spike antigen-specific IgG and IgA elicited by infection mediate viral neutralization and are likely an important component of natural immunity, however, limited information exists on vaccine induced responses. We measured COVID-19 mRNA vaccine induced IgG and IgA in serum serially, up to 80 days post vaccination in 4 subjects. Spike antigen-specific IgG levels rose exponentially and plateaued 21 days after the initial vaccine dose. After the second vaccine dose IgG levels increased further, reaching a maximum approximately 7-10 days later, and remained elevated (average of 78% peak levels) during the additional 20-50 day follow up period. COVID-19 mRNA vaccination elicited spike antigen-specific IgA with similar kinetics of induction and time to peak levels, but more rapid decline in serum levels following both the 1st and 2nd vaccine doses (<23% peak levels within 80 days of the initial shot). The data demonstrate COVID-19 mRNA vaccines effectively induce spike antigen specific IgG and IgA and highlight marked differences in their persistence in serum.

Determination of Specific IgG Antibody by Crossed Radioimmunoelectrophoresis

Allergy ◽  
1983 ◽  
Vol 38 (3) ◽  
pp. 183-189 ◽  
Author(s):  
S. L. Nordvall ◽  
T. Uhlin ◽  
R. Einarsson
Keyword(s):  
Igg Antibody ◽  
Specific Igg
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