scholarly journals SENSITIVITY OF THREE THYROTROPIN RECEPTOR ANTIBODY ASSAYS IN THYROID-ASSOCIATED ORBITOPATHY

2021 ◽  
Author(s):  
Marija Sarić Matutinović ◽  
Tania Diana ◽  
Biljana Nedeljković Beleslin ◽  
Jasmina Ćirić ◽  
Miloš Žarković ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Thyrotropin Receptor ◽  
Binding Assays ◽  
Serum Samples ◽  
Laboratory Assessment ◽  
Predictive Values ◽  
Clinical Sensitivity ◽  
Thyrotropin Receptor Antibody ◽  
Antibody Assays ◽  
Sensitivity Rate

Background: Thyrotropin receptor autoantibodies (TSH-R-Ab) are indispensable biomarkers in the laboratory assessment of thyroid-associated orbitopathy (TAO). Clinical sensitivity of three different assays for TSH-R-Ab determination was evaluated in patients with TAO. Methods: 87 consecutive TAO patients were enrolled and their serum samples analyzed in parallel with three assays. An ECLIA competitive binding and a chemiluminescent bridge immunoassay were used to measure total and binding TSH-R-Ab concentration, while their functional activity was determined using a stimulatory TSH-R-Ab (TSAb) cell-based bioassay. Results: Compared to the two binding assays (ECLIA p<0.001, bridge p=0.003), the TSAb bioassay was more sensitive pertaining to the positive detection of TSH-R-Ab in TAO patients. No difference (p=0.057) was noted between the ECLIA and bridge assays regarding sensitivity rate. All patients with active and/or moderate-to-severe TAO tested positive in the TSAb bioassay (100% and 100%, respectively), while the positivity rates for bridge and ECLIA binding assays were 89.7% and 82.1% for active TAO, and 90.2% and 86.3% for severe TAO, respectively. Negative predictive values of the bioassay, bridge, and ECLIA assays were 100%, 75%, and 71%, respectively for active TAO, and 100%, 86%, and 71%, respectively for moderate-to-severe TAO. The superiority of the bioassay was most prominent in euthyroid (ET) TAO. Positivity rates of the TSAb bioassay, bridge and ECLIA binding assays were 89.6%, 75%, and 64.6%, respectively for inactive TAO; 86.1%, 69.4%, and 52.8%, respectively for mild TAO; 87.5%, 62.5%, and 12.5%, respectively for euthyroid TAO. The bridge assay correlated better with the ECLIA binding assay (ρ=0.893, p<0.001), compared to the bioassay (ρ=0.669, p<0.001). Conclusions: In patients with TAO of various activity and severity, the TSAb bioassay demonstrates a superior clinical performance compared to both ECLIA and bridge binding assays.

scholarly journals Analytical and clinical performance of a homogeneous enzymatic LDL-cholesterol assay compared with the ultracentrifugation-dextran sulfate-Mg2+ method

1998 ◽  
Vol 44 (6) ◽  
pp. 1242-1250 ◽  
Author(s):  
Nader Rifai ◽  
Elizabeth Iannotti ◽  
Kristen DeAngelis ◽  
Terence Law
Keyword(s):  
Dextran Sulfate ◽  
Ldl Cholesterol ◽  
Clinical Performance ◽  
Total Error ◽  
Analytical Performance ◽  
Medical Decision ◽  
Serum Samples ◽  
Predictive Values ◽  
Clinical Laboratories ◽  
Wide Range

Abstract LDL-cholesterol (LDL-C) concentration is currently determined in most clinical laboratories by the Friedewald calculation. This approach has several limitations and may not meet the current total error requirement in LDL-C measurement of ≤ 12%. We evaluated the analytical and clinical performance of the direct N-geneous LDL-C assay (Equal Diagnostics). The N-geneous method correlated highly with the modified beta-quantification assay (r = 0.95; y = 0.91x + 70.6 mg/L; n = 199), showed no significant effect of increased triglyceride or other common interferants, and performed adequately in serum samples from nonfasting individuals. This assay demonstrated a mean total error of 6.75% over a wide range of LDL-C concentrations. In addition, at the medical decision cutoff points, this LDL-C assay showed positive predictive values of 78–95% and negative predictive values of 84–99%. We conclude that the N-geneous LDL-C meets the currently established analytical performance goals and appears to have a role in the diagnosis and management of hypercholesterolemic patients.

scholarly journals Thyrotropin Receptor Antibody Assays

2013 ◽  
Vol 139 (2) ◽  
pp. 140-142 ◽  
Author(s):  
William E. Winter ◽  
Ishwarlal Jialal ◽  
Sridevi Devaraj
Keyword(s):  
Thyrotropin Receptor ◽  
Receptor Antibody ◽  
Thyrotropin Receptor Antibody ◽  
Antibody Assays

scholarly journals Side-by-Side Comparison of Three Fully Automated SARS-CoV-2 Antibody Assays with a Focus on Specificity

2020 ◽  
Vol 66 (11) ◽  
pp. 1405-1413 ◽  
Author(s):  
Thomas Perkmann ◽  
Nicole Perkmann-Nagele ◽  
Marie-Kathrin Breyer ◽  
Robab Breyer-Kohansal ◽  
Otto C Burghuber ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Test Performance ◽  
Clinical Performance ◽  
Serological Test ◽  
Cohen’S Kappa ◽  
Predictive Values ◽  
Test Systems ◽  
Cohen's Kappa ◽  
Antibody Assays ◽  
Good Agreement

Abstract Background In the context of the COVID-19 pandemic, numerous new serological test systems for the detection of anti-SARS-CoV-2 antibodies rapidly have become available. However, the clinical performance of many of these is still insufficiently described. Therefore, we compared 3 commercial CE-marked, SARS-CoV-2 antibody assays side by side. Methods We included a total of 1154 specimens from pre-COVID-19 times and 65 samples from COVID-19 patients (≥14 days after symptom onset) to evaluate the test performance of SARS-CoV-2 serological assays by Abbott, Roche, and DiaSorin. Results All 3 assays presented with high specificities: 99.2% (98.6–99.7) for Abbott, 99.7% (99.2–100.0) for Roche, and 98.3% (97.3–98.9) for DiaSorin. In contrast to the manufacturers’ specifications, sensitivities only ranged from 83.1% to 89.2%. Although the 3 methods were in good agreement (Cohen’s Kappa 0.71–0.87), McNemar tests revealed significant differences between results obtained from Roche and DiaSorin. However, at low seroprevalences, the minor differences in specificity resulted in profound discrepancies of positive predictive values at 1% seroprevalence: 52.3% (36.2–67.9), 77.6% (52.8–91.5), and 32.6% (23.6–43.1) for Abbott, Roche, and DiaSorin, respectively. Conclusion We found diagnostically relevant differences in specificities for the anti-SARS-CoV-2 antibody assays by Abbott, Roche, and DiaSorin that have a significant impact on the positive predictive values of these tests.

scholarly journals Performance of the commercially available SERION ELISA classic Echinococcus IgG test for the detection of cystic echinococcosis in clinical practice

2018 ◽  
Vol 93 (05) ◽  
pp. 636-639 ◽  
Author(s):  
M.J. Sarink ◽  
R. Koelewijn ◽  
B.C.G.C. Slingerland ◽  
A.G.M. Tielens ◽  
P.J.J. van Genderen ◽  
...  
Keyword(s):  
Cystic Echinococcosis ◽  
Clinical Performance ◽  
Imaging Techniques ◽  
Healthy Controls ◽  
Imaging Studies ◽  
Serum Samples ◽  
Predictive Values ◽  
Complementary Role ◽  
Negative Controls ◽  
Positive Results

AbstractDiagnosis of cystic echinococcosis (CE) is at present mainly based on imaging techniques. Serology has a complementary role, partly due to the small number of standardized and commercially available assays. Therefore we examined the clinical performance of the SERION ELISA classic Echinococcus IgG test. Using 10 U/ml as a cut-off point, and serum samples from 50 CE patients and 105 healthy controls, the sensitivity and specificity were 98.0% and 96.2%, respectively. If patients with other infectious diseases were used as negative controls, the specificity decreased to 76.9%, which causes poor positive predictive values. However, if results between 10 and 15 U/ml are classified as indecisive, the specificity of positive results (≥15 U/ml) increased to 92.5% without greatly affecting the sensitivity (92.0%). Using this approach in combination with imaging studies, the SERION ELISA classic Echinococcosis IgG test can be a useful aid in the diagnosis of CE.

scholarly journals Population (Antibody) Testing for COVID-19—Technical Challenges, Application and Relevance, an English Perspective

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 550
Author(s):  
Peter A. C. Maple
Keyword(s):  
National Level ◽  
Herd Immunity ◽  
Population Based ◽  
Biological Properties ◽  
Limited Extent ◽  
Antibody Testing ◽  
Serum Samples ◽  
Oral Fluids ◽  
Antibody Assays ◽  
The Uk

In the UK, population virus or antibody testing using virus swabs, serum samples, blood spots or oral fluids has been performed to a limited extent for several diseases including measles, mumps, rubella and hepatitis and HIV. The collection of population-based infection and immunity data is key to the monitoring of disease prevalence and assessing the effectiveness of interventions such as behavioural modifications and vaccination. In particular, the biological properties of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its interaction with the human host have presented several challenges towards the development of population-based immunity testing. Measuring SARS-CoV-2 immunity requires the development of antibody assays of acceptable sensitivity and specificity which are capable of accurately detecting seroprevalence and differentiating protection from non-protective responses. Now that anti-COVID-19 vaccines are becoming available there is a pressing need to measure vaccine efficacy and the development of herd immunity. The unprecedented impact of the SARS-CoV-2 pandemic in the UK in terms of morbidity, mortality, and economic and social disruption has mobilized a national scientific effort to learn more about this virus. In this article, the challenges of testing for SARS-CoV-2 infection, particularly in relation to population-based immunity testing, will be considered and examples given of relevant national level studies.

scholarly journals Long-Term Longitudinal Evaluation of Six Commercial Immunoassays for the Detection of IgM and IgG Antibodies against SARS CoV-2

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1244
Author(s):  
Iulia Nedelcu ◽  
Raluca Jipa ◽  
Roxana Vasilescu ◽  
Cristian Băicuș ◽  
Costin-Ioan Popescu ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Sample Selection ◽  
Early Time ◽  
Humoral Response ◽  
High Specificity ◽  
Data Interpretation ◽  
Serum Samples ◽  
Chemiluminescent Immunoassay ◽  
Chemiluminescent Microparticle Immunoassay ◽  
Antibody Levels

The number of serological assays for SARS-CoV-2 has skyrocketed in the past year. Concerns have been raised regarding their performance characteristics, depending on the disease severity and the time of the analysis post-symptom onset (PSO). Thus, independent validations using an unbiased sample selection are required for meaningful serology data interpretation. We aimed to assess the clinical performance of six commercially available assays, the seroconversion, and the dynamics of the humoral response to SARS-CoV-2 infection. The study included 528 serum samples from 156 patients with follow-up visits up to six months PSO and 161 serum samples from healthy people. The IgG/total antibodies positive percentage increased and remained above 95% after six months when chemiluminescent immunoassay (CLIA) IgG antiS1/S2 and electro-chemiluminescent assay (ECLIA) total antiNP were used. At early time points PSO, chemiluminescent microparticle immunoassay (CMIA) IgM antiS achieved the best sensitivity. IgM and IgG appear simultaneously in most circumstances, and when performed in parallel the sensitivity increases. The severe and the moderate clinical forms were significantly associated with higher seropositivity percentage and antibody levels. High specificity was found in all evaluated assays, but the sensitivity was variable depending on the time PSO, severity of disease, detection method and targeted antigen.

scholarly journals Investigation of the rapid immunochromatographic test performance in the diagnosis of syphilis; comparison of four serological methods

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Huseyin Agah Terzi ◽  
Ozlem Aydemir ◽  
Engin Karakece ◽  
Huseyin Hatipoglu ◽  
Mehmet Olmez ◽  
...  
Keyword(s):  
Test Performance ◽  
Gold Standard ◽  
Treponema Pallidum ◽  
Rapid Test ◽  
Immunochromatographic Test ◽  
Rapid Plasma Reagin ◽  
Serum Samples ◽  
Hemagglutination Assay ◽  
Predictive Values ◽  
Sensitivity Specificity

AbstractObjectivesTo test the performance of the newly available rapid test for syphilis, we compared it with Treponema pallidum hemagglutination assay (TPHA). Additionally, we investigated the performance of rapid plasma reagin (RPR) and chemiluminescence microparticle immunoassays (CMIA) at our laboratory using TPHA as a gold standard.MethodsThe serum samples of 595 patients with the pre-diagnosis of syphilis were studied by four serological methods. The sensitivity, specificity, and predictive values of RPR, CMIA, and syphilis rapid test were assessed by utilizing TPHA as a gold standard for the diagnosis of syphilis.ResultsOf the patients, 6.2% (37/595) had positive RPR, 5.5% (33/595) had positive CMIA, 5.5% (33/595) had a positive rapid immunochromatographic method and 5% (30/595) had positive TPHA. When TPHA results were taken as the reference, the sensitivity of the rapid test for syphilis was 100%, the specificity was 99.5%, PPV was 90.9%, and NPV was 100.0%.ConclusionsIt was observed that the rapid test for syphilis used in the study was quite successful, its cost was appropriate, and the test was very fast and easy to apply. At the same time, the agreement between syphilis rapid test and TPHA was found to be excellent.

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