Electrophoresis Titration Model of a Moving Redox Boundary Chip for a Point-of-Care Test of an Enzyme-Linked Immunosorbent Assay

ACS Sensors ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 126-133 ◽  
Author(s):  
Fan-Zhi Kong ◽  
Sharmin Jahan ◽  
Ran Zhong ◽  
Xin-Yu Cao ◽  
Wen-Lin Li ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Point Of Care ◽  
Enzyme Linked Immunosorbent Assay ◽  
Point Of Care Test ◽  
Redox Boundary

scholarly journals Comparative Analysis of the Euroimmun CXCL13 Enzyme-Linked Immunosorbent Assay and the ReaScan Lateral Flow Immunoassay for Diagnosis of Lyme Neuroborreliosis

2020 ◽  
Vol 58 (9) ◽  
Author(s):  
Katharina Ziegler ◽  
Anca Rath ◽  
Christoph Schoerner ◽  
Renate Meyer ◽  
Thomas Bertsch ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Roc Curve ◽  
Point Of Care ◽  
Lateral Flow ◽  
Lyme Neuroborreliosis ◽  
Diagnostic Tools ◽  
Lateral Flow Immunoassay ◽  
Enzyme Linked Immunosorbent Assay ◽  
European Federation ◽  
Point Of Care Test

ABSTRACT Diagnosis of Lyme neuroborreliosis (LNB) is challenging, as long as Borrelia-specific intrathecal antibodies are not yet detectable. The chemokine CXCL13 is elevated in the cerebrospinal fluid (CSF) of LNB patients. Here, we compared the performances of the Euroimmun CXCL13 enzyme-linked immunosorbent assay (CXCL13 ELISA) and the ReaScan CXCL13 lateral flow immunoassay (CXCL13 LFA), a rapid point-of-care test, to support the diagnosis of LNB. In a dual-center case-control study, CSF samples from 90 patients (34 with definite LNB, 10 with possible LNB, and 46 with other central nervous system [CNS] diseases [non-LNB group]) were analyzed with the CXCL13 ELISA and the CXCL13 LFA. Classification of patients followed the European Federation of Neurological Societies (EFNS) guidelines on LNB. The CXCL13 ELISA detected elevated CXCL13 levels in all patients with definite LNB (median, 1,409 pg/ml) compared to the non-LNB controls (median, 20.7 pg/ml; P < 0.0001), with a sensitivity of 100% and a specificity of 84.8% (cutoff value, 78.6 pg/ml; area under the receiver operating characteristic [ROC] curve, 0.93). Similarly, the CXCL13 LFA yielded elevated CXCL13 levels in 31 patients with definite LNB (median arbitrary value, 223.5) compared to the non-LNB control patients (median arbitrary value, 0; P < 0.0001) and had a sensitivity and specificity of 91.2% and 93.5%, respectively (cutoff arbitrary value, 22.5; area under the ROC curve, 0.94). The correlation between the CXCL13 levels obtained by ELISA and LFA was strong (Spearman correlation coefficient r = 0.89; P < 0.0001). The CXCL13 ELISA and the CXCL13 LFA are comparable diagnostic tools for the detection of CXCL13 in the CSF of patients with definite LNB. The advantage of the CXCL13 LFA is the shorter time to result.

scholarly journals Heparin Binding Protein and Endothelial Glycocalyx Markers in Severe COVID-19 – A Prospective Observational Cohort Study

2020 ◽  
Author(s):  
Lisa Mellhammar ◽  
Louise Thelaus ◽  
Sixten Elén ◽  
Jane Fisher ◽  
Adam Linder
Keyword(s):  
Organ Dysfunction ◽  
Binding Protein ◽  
Point Of Care ◽  
Severe Disease ◽  
Endothelial Glycocalyx ◽  
Enzyme Linked Immunosorbent Assay ◽  
Heparin Binding ◽  
Convenience Sample ◽  
Point Of Care Test ◽  
Heparin Binding Protein

Abstract Background: The pathophysiology of severe COVID-19 has been implicated to involve neutrophil activation in the blood and in the lungs and endothelial dysfunction. Heparin binding protein (HBP) is a neutrophil protein that plays an important role in bacterial sepsis and is a promising biomarker in severe infections. Syndecans and glypicans are potential markers of sheeding of the glycocalyx and endothelial dysfunction.The primary aims of this study were to assess whether HBP or syndecans and glypicans are involved in the pathophysiology of COVID-19 and if so, whether they can be used to predict severe disease preferably using a point-of-care test (POC) that can substitute more time-consuming analysis with enzyme-linked immunosorbent assay (ELISA).Methods: A prospective convenience sample study of biomarkers. The main cohort consisted of patients admitted to hospital with a confirmed COVID-19 diagnosis. Samples and clinical data were collected at admission, during admission and at discharge and samples were analyzed with ELISA kit (Axis-Shield Diagnostics) for measuring HBP concentration and a novel dry immunofluorescence analyzer (Jet-iStar 800) (Joinstar) for point-of-care testing.Results: Thirty-five COVID-19 patients were prospectively enrolled in the study. HBP was significantly elevated in COVID-19 patients with organ dysfunction (n= 23) compared to those without organ dysfunction (n=6), 24.7 ng/mL (95% CI 17.3-48.4) vs 10.6 ng/mL (95% CI 6.2-17.1 ng/mL), p=0.03. Syndecan-1 and Glypican-4 were not significantly elevated in patients with organ dysfunction. Syndecan-1, 62.1 ng/mL (44.4-102.0) vs 57.5 ng/mL (95% CI 46.0- 63.7), p=0.44 and glypican-4, 3292.4 pg/mL (95% CI 1707.5- 6790.6) vs 3962.7 pg/mL (95% CI 2653.6- 5823.5), p=0.80. The point-of-care (POC) HBP test showed good correlation to the standard ELISA with an R-value of 0.83. HBP measured by the POC device predicted development of COVID-induced organ dysfunction within 72 hours with an AUC of 0.88.Conclusions: The neutrophil-derived HBP is elevated prior to onset of organ dysfunction in patients with severe COVID-19 using a newly developed point-of-care test and hence HBP could be used in a clinical setting as a prognostic marker in COVID-19.

scholarly journals Evaluation of commercially available immuno-magnetic agglutination and enzyme-linked immunosorbent assays for rapid point-of-care diagnostics of COVID-19

2020 ◽  
Author(s):  
Maria Engel Moeller ◽  
Jeppe Fock ◽  
Pearlyn Pah ◽  
Antia De La Campa Veras ◽  
Melanie Bade ◽  
...  
Keyword(s):  
Point Of Care ◽  
Enzyme Linked Immunosorbent Assay ◽  
Plasma Samples ◽  
Igg Antibodies ◽  
Chain Reaction ◽  
Point Of Care Test ◽  
Point Of Care Diagnostics ◽  
Polymerase Chain ◽  
Respiratory Coronavirus ◽  
Immunomagnetic Assay

Introduction: Coronavirus Disease 2019 (COVID-19) is caused by severe acute respiratory coronavirus-2 (SARS-CoV-2). Fast, accurate and simple blood-based assays for quantification of anti-SARS-CoV-2 antibodies are urgently needed to identify infected individuals and keep track of the spread of disease. Methods: The study included 35 plasma samples from 22 individuals with confirmed COVID-19 by real time reverse transcriptase polymerase chain reaction and 40 non COVID-19 plasma samples. Anti-SARS-CoV-2 IgM/IgA or IgG antibodies were detected by a microfluidic quantitative immunomagnetic assay (IMA)(ViroTrack Sero COVID IgM+IgA/IgG Ab, Blusense Diagnostics, Denmark) and by enzyme-linked immunosorbent assay ((ELISA) (EuroImmun Medizinische Labordiagnostika, Germany). Results: Of the 35 plasma samples from the COVID-19 patients, 29 (82.9%) were positive for IgA/IgM or IgG by IMA and 29 samples (82.9%) were positive by ELISA. Sensitivity for only one sample per patient was 68% for IgA+IgM and 73% IgG by IMA and 73% by ELISA. For samples collected 14 days after symptom onset, the sensitivity of both IMA and ELISA was around 90%. Specificity of the IMA reached 100% compared to 95% for ELISA IgA and 97.5% for ELISA IgG. Conclusion: IMA for COVID-19 is a rapid simple-to-use point of care test with sensitivity and specificity similar to a commercial ELISA.

scholarly journals Rapid Point-of-Care Test To Detect Broad Ranges of Protective Antigen-Specific Immunoglobulin G Concentrations in Recipients of the U.S.-Licensed Anthrax Vaccine

2008 ◽  
Vol 15 (4) ◽  
pp. 644-649 ◽  
Author(s):  
Diane R. Bienek ◽  
Raymond E. Biagini ◽  
David G. Charlton ◽  
Jerome P. Smith ◽  
Deborah L. Sammons ◽  
...  
Keyword(s):  
High Temperature ◽  
Relative Humidity ◽  
Immunoglobulin G ◽  
Protective Antigen ◽  
Point Of Care ◽  
Enzyme Linked Immunosorbent Assay ◽  
Anthrax Vaccine ◽  
Point Of Care Test ◽  
Specificity And Sensitivity ◽  
Specific Igg

ABSTRACT Currently, there is no routine monitoring of an immune response to the anthrax vaccine. Simple on-site tests are needed to evaluate the antibody response of anthrax-vaccinated individuals in the Armed Forces and others at high risk. Using a prototype lateral flow assay (LFA) (R. E. Biagini, D. L. Sammons, J. P. Smith, B. A. MacKenzie, C. A. F. Striley, J. E. Snawder, S. A. Robertson, and C. P. Quinn, Clin. Vaccine Immunol. 13:541-546, 2006), we investigated the agreement between a validated anthrax protective antigen (PA) immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) and the LFA for 335 unvaccinated and vaccinated subjects. We also investigated the performance of the LFA under the following conditions: thermal shock (i.e., thermal cycling between temperature extremes), high temperature/high relative humidity, high temperature/low relative humidity, and low temperature/low relative humidity. With the anti-PA ELISA used as a standard, the LFA was shown to be optimally diagnostic at 11 μg/ml anti-PA-specific IgG. At this concentration, the LFA specificity and sensitivity were 98% (95% confidence interval [CI], 97% to 100%) and 92% (CI, 88% to 97%), respectively. Receiver operating characteristic curve analysis yielded an area under the curve value of 0.988 (CI, 0.976 to 1.00), suggesting that the LFA is an extremely accurate diagnostic test. For ≤4 or ≥50 μg/ml PA-specific IgG, the LFA results for each environmental condition were identical to those obtained in the laboratory. These data indicate that this rapid point-of-care test would be a feasible tool in monitoring the serological antibody responses of individuals that have been vaccinated against anthrax.

scholarly journals Novel Coronavirus: What to Learn from a Microbiologist?

2020 ◽  
Vol 5 (03) ◽  
pp. 282-284
Author(s):  
Deepinder K. Chhina ◽  
Jyoti Chaudhary
Keyword(s):  
Point Of Care ◽  
Respiratory Illness ◽  
Standard Test ◽  
World Health ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Point Of Care Test ◽  
Novel Coronavirus ◽  
Health Organization ◽  
Antigen Testing

AbstractIn December 2019, an outbreak of coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) was declared in Wuhan, city of China. Later on, the World Health Organization declared COVID-19 as a pandemic on March 11, 2020. The clinical course of the disease ranges from asymptomatic cases to fatal severe respiratory illness. Various laboratory tests are available for the diagnosis of disease. The gold standard test is real-time PCR (polymerase chain reaction), whereas antigen testing can be used as a point-of-care test. Antibody detection by ELISA (enzyme-linked immunosorbent assay) can be used for the surveillance of the immune response.

Sign in / Sign up

Export Citation Format

Share Document