Revisiting the dilution factor as vital parameter for sensitivity of ELISA assay in CSF and Plasma

SummaryD-dimer (DD), when measured by a quantitative enzyme-linked immunosorbent assay (ELISA), is a valuable test to exclude venous thromboembolism (VTE). However, DD ELISA technique is not appropriate for emergency use and the available agglutination latex assays are not sensitive enough to be used as an alternative to rule out the diagnosis of VTE. Latex assays could still be used as screening tests. We tested this hypothesis by comparing DD levels measured by ELISA and latex assays in 334 patients suspected of pulmonary embolism. All but one patient with a positive (DD ≥500 ng/ml) latex assay had DD levels higher than 500 ng/ml with the ELISA assay. Accordingly, ELISA technique could be restricted to patients with a negative result in latex assay. This two-step approach would have spared about 50% of ELISA in our cohort. In conclusion, our data indicate that a latex test can be used as a first diagnostic step to rule out pulmonary embolism provided a negative result is confirmed by ELISA and the performance of the latex assay used has been assessed properly.

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Measurement of 25-hydroxyvitamin D: evaluation of the new DIAsource ELISA assay

Endocrine Abstracts ◽

10.1530/endoabs.32.p148 ◽

2013 ◽

Author(s):

Sophie Huvelle ◽

Thibault Lepoutre ◽

Nicolas Heureux ◽

Damien Gruson

Keyword(s):

Elisa Assay ◽

Hydroxyvitamin D ◽

25 Hydroxyvitamin D

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Validation of a novel ELISA assay for serum AMH determination

10.26226/morressier.5af300b3738ab10027aa99af ◽

2018 ◽

Author(s):

Askan Schultze - Mosgau ◽

Kay Neumann ◽

Georg Griesinger

Keyword(s):

Elisa Assay

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Protective effect of a new heterocyclic compound on acute tracheobronchitis via reducing IL-6 and TNF-α content and PKA-NF-κB pathway activation

Main Group Chemistry ◽

10.3233/mgc-210006 ◽

2021 ◽

Vol 20 (1) ◽

pp. 41-48

Author(s):

Ai-Ping Han ◽

Li Li

Keyword(s):

Protective Effect ◽

Heterocyclic Compound ◽

Biological Study ◽

Elisa Assay ◽

Mice Model ◽

X Ray ◽

X Ray Crystallography ◽

Pathway Activation ◽

Tnf Α ◽

Amino Benzoic Acid

The new heterocyclic compound 4-methyl-3-((4-(pyridin-3-yl) pyrimidin-2-yl) amino) benzoic acid (1) designed utilizing methyl 3-amino-4-methylbenzoate (2) as a starting material was successfully fabricated and eventually characterized utilizing single crystal X-ray crystallography, 1H NMR and IR. In biological study, to evaluate the protective effect of compound on acute tracheobronchitis ICR mice model, the ELISA assay was performed to determine the level of inflammatory mediators IL-6 and TNF-α in serum. Then, the western blot was performed to determine the activation of PKA-NF-κB pathway in tissues.

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Seroprevalence of Anti-SARS-CoV-2 IgG and IgM among Adults over 65 Years Old in the South of Italy

Diagnostics ◽

10.3390/diagnostics11030483 ◽

2021 ◽

Vol 11 (3) ◽

pp. 483

Author(s):

Immacolata Polvere ◽

Alfredina Parrella ◽

Giovanna Casamassa ◽

Silvia D’Andrea ◽

Annamaria Tizzano ◽

...

Keyword(s):

Antibody Response ◽

Immunoglobulin M ◽

Molecular Testing ◽

Elisa Assay ◽

The South ◽

Serum Samples ◽

Serological Screening ◽

Rna Detection ◽

In Vitro Diagnostic

SARS-CoV-2 is a zoonotic betacoronavirus associated with worldwide transmission of COVID-19 disease. By the beginning of March, WHO reported about 113,820,000 confirmed cases including more than 2,527,000 deaths all over the world. However, the true extent of virus circulation or its real infection/fatality ratio is not well-estimated due to the huge portion of asymptomatic infections. In this observational study, we have estimated the prevalence of specific immunoglobulin M and G directed towards SARS-CoV-2 antigen in a cohort of 1383 adult volunteers aged over 65 years old, living in the district of Benevento, in the South of Italy. Serological screening was carried out on capillary blood in September 2020, seven months after pandemic outbreak in Italy, to evaluate virus circulation and antibody response among elderly adults, in which severe symptoms due to viral infection are more common. The overall seroprevalence of anti-SARS-CoV-2 antibodies was 4.70% (CI 3.70%–5.95%) with no statistically significant differences between sexes. Among these, 69.69% (CI 55.61%–77.80%) tested positive to IgM, 23.08% (CI 14.51%–34.64%) to IgG and 9.23% (CI 4.30%–18.71%) was positive for both. All patients that were positive to IgM underwent molecular testing through RT-qPCR on oral-rhino pharyngeal swabs and only one specimen was positive for SARS-CoV-2 RNA detection. Instead, the presence of IgG from screened volunteers was confirmed by re-testing serum samples using both an ELISA assay validated for in vitro diagnostic use (IVD) and a recently published synthetic peptide-based ELISA assay. In conclusion, our report suggests that (1) early restrictions were successful in limiting COVID-19 diffusion in the district of Benevento; (2) rapid serological analysis is an ideal testing for both determining real seroprevalence and massive screening, whereas detection of viral RNA remains a gold standard for identification of infected patients; (3) even among people without COVID-19 related symptoms, the antibody response against SARS-CoV-2 antigens has individual features.

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Plasma Biomarkers Screening by Multiplex ELISA Assay in Patients with Advanced Non-Small Cell Lung Cancer Treated with Immune Checkpoint Inhibitors

Cancers ◽

10.3390/cancers13010097 ◽

2020 ◽

Vol 13 (1) ◽

pp. 97

Author(s):

Adrien Costantini ◽

Paul Takam Kamga ◽

Catherine Julie ◽

Alexandre Corjon ◽

Coraline Dumenil ◽

...

Keyword(s):

Lung Cancer ◽

Growth Factor ◽

Immune Checkpoint ◽

Immune Checkpoint Inhibitors ◽

Advanced Nsclc ◽

Checkpoint Inhibitors ◽

Small Cell ◽

Elisa Assay ◽

Small Cell Lung ◽

Plasma Biomarkers

Immune checkpoint inhibitors (ICIs) are commonly used in patients with advanced non-small cell lung cancer (NSCLC). An unmet need remains for new biomarkers associated with ICIs. In this study, consecutive patients with advanced NSCLC treated with nivolumab or pembrolizumab were included. Plasma at ICIs initiation was prospectively collected and a multiplex ELISA assay testing 48 cytokines and growth factors was performed. Exploratory endpoints were the association between plasma biomarkers with outcome and grade III–IV immune related adverse events (irAEs). Thirty-five patients were included. Patients without clinical benefit (n = 22) had higher pre-ICI soluble Hepatocyte Growth Factor (sHGF) (210.9 vs. 155.8 pg/mL, p = 0.010), lower pre-ICI soluble Fibroblast Growth Factor (sFGF) (4.0 vs. 4.8 pg/mL, p = 0.043) and lower pre-ICI interleukine-12 (IL-12) (1.3 vs. 2.2 pg/mL, p = 0.043) concentrations. Patients with early progression (n = 23) had higher pre-ICIs sHGF (206.2 vs. 155.8 pg/mL, p = 0.025) concentrations. Patients with low sHGF levels at ICIs initiation had longer progression-free survival and overall survival than those with high sHGF levels: respectively 2.5 vs. 8.0 months (p = 0.002), and 5.5 vs. 35.0 months (p = 0.001). TNF-α, IL-16, IL-12p40 and MCP3 were associated with high grade irAEs. This study shows the potential association between several plasma biomarkers with outcome and grade 3–4 IrAEs in advanced NSCLC treated with ICIs.

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A Bayesian approach to estimate the accuracy of "in-house" ELISA assay to measure rabies antibodies from compulsory vaccinated dogs and cattle

Journal of Venomous Animals and Toxins including Tropical Diseases ◽

10.1590/s1678-91992009000100012 ◽

2009 ◽

Vol 15 (1) ◽

pp. 136-145

Author(s):

AHC Nogueira ◽

C Silva ◽

DE Gomes ◽

ACG Rosa ◽

MCR Luvizotto ◽

...

Keyword(s):

Bayesian Approach ◽

Elisa Assay

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Evaluation of the binding affinity of E3 ubiquitin ligase ligands by cellular target engagement and in-cell ELISA assay

STAR Protocols ◽

10.1016/j.xpro.2020.100288 ◽

2021 ◽

Vol 2 (1) ◽

pp. 100288

Author(s):

Ka Yang ◽

Yaxian Zhou ◽

Brett L. Roberts ◽

Xueqing Nie ◽

Weiping Tang

Keyword(s):

Binding Affinity ◽

Ubiquitin Ligase ◽

E3 Ubiquitin Ligase ◽

Elisa Assay ◽

Target Engagement ◽

Cellular Target ◽

Cell Elisa

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Validity of different copeptin assays in the differential diagnosis of the polyuria-polydipsia syndrome

Scientific Reports ◽

10.1038/s41598-021-89505-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Clara Odilia Sailer ◽

Julie Refardt ◽

Claudine Angela Blum ◽

Ingeborg Schnyder ◽

Jose Alberto Molina-Tijeras ◽

...

Keyword(s):

Differential Diagnosis ◽

Diagnostic Accuracy ◽

Healthy Volunteers ◽

Primary Outcome ◽

The Other ◽

Poor Correlation ◽

Elisa Assay ◽

Moderate Correlation ◽

High Diagnostic Accuracy ◽

Osmotic Stimulation

AbstractThe aim of this study was to correlate three commercially available copeptin assays and their diagnostic accuracy in the differential diagnosis of the polyuria-polydipsia syndrome. Analyzed data include repeated copeptin measures of 8 healthy volunteers and 40 patients with polyuria-polydipsia syndrome undergoing osmotic stimulation and of 40 patients hospitalized with pneumonia. Copeptin was measured using the automated Brahms KRYPTOR, the manual Brahms LIA and the manual Cloud Clone ELISA assay. Primary outcome was the interrater correlation coefficient (ICC) and diagnostic accuracy in the polyuria-polydipsia syndrome of the three assays. In healthy volunteers, there was a moderate correlation for the KRYPTOR and LIA (ICC 0.74; 95% CI 0.07 to 0.91), and a poor correlation for the KRYPTOR and ELISA (ICC 0.07; 95% CI − 0.06 to 0.29), as for the LIA and ELISA (ICC 0.04; 95% CI − 0.04 to 0.17). The KRYPTOR had the highest diagnostic accuracy (98% (95% CI 83 to100)), comparable to the LIA (88% (95% CI 74 to 100)), while the ELISA had a poor diagnostic accuracy (55% (95% CI 34 to 68)) in the differential diagnosis of the polyuria-polydipsia syndrome. The KRYPTOR and LIA yield comparable copeptin concentrations and high diagnostic accuracy, while the ELISA correlates poorly with the other two assays and shows a poor diagnostic accuracy for polyuria-polydipsia patients. The current copeptin cut-off is valid for the KRYPTOR and LIA assay. Our results indicate that interpretation with other assays should be performed with caution and separate validation studies are required before their use in differentiating patients with polyuria-polydipsia syndrome.Trial registration: NCT02647736 January 6, 2016/NCT01940614 September 12, 2013/NCT00973154 September 9, 2009.

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