scholarly journals Evaluation and Validation of an Enzyme-Linked Immunosorbent Assay and an Immunochromatographic Test for Serological Diagnosis of Severe Acute Respiratory Syndrome

2004 ◽  
Vol 11 (4) ◽  
pp. 699-703 ◽  
Author(s):  
Ming Guan ◽  
Kwok Hung Chan ◽  
J. S. Malik Peiris ◽  
See Wai Kwan ◽  
Siu Yan Lam ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Immunosorbent Assay ◽  
Clinical Symptoms ◽  
Rapid Test ◽  
High Specificity ◽  
Clinical Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immunochromatographic Test ◽  
Detection Rates ◽  
Specific Antibodies

ABSTRACT A newly developed severe acute respiratory syndrome (SARS)-specific enzyme-linked immunosorbent assay (ELISA) was further validated to confirm cutoff values and evaluate its diagnostic performance with clinical samples. In parallel, an immunochromatographic test was also evaluated. A total of 227 clinical serum specimens collected from SARS patients were used in the study, together with 385 samples from healthy donors. By use of an immunofluorescent (IF) test as the “gold standard, ” both the ELISA and the immunochromatographic test were able to detect immunoglobulin G antibodies to SARS not only from late-convalescent-stage samples (>21 days from the onset of clinical symptoms), as previously established, but also from early-acute-phase samples (1 to 10 days from onset). The ELISA, using an optical density (OD) of 0.25 as its cutoff value, produced the best sensitivity while maintaining high specificity. It detected SARS-specific antibodies in 58, 70, 75, and 95%, respectively, of the four groups of samples collected from patients 1 to 10 days, 11 to 20 days, 21 to 30 days, and more than 30 days after the onset of clinical symptoms. Similarly, the immunochromatographic test detected SARS-specific antibodies in 55, 68, 81, and 79% of the four groups, respectively. The overall specificities for the ELISA and the rapid test were 99.5 and 97.7%, respectively. Although the positive correlation observed between the ELISA OD values and the IF titers was moderate (r = 0.6915; P < 0.001), the detection rates of both the ELISA and the rapid test were found well in agreement with the IF titers.

scholarly journals A Dual-Antigen Enzyme-Linked Immunosorbent Assay Allows the Assessment of Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Seroprevalence in a Low-Transmission Setting

2020 ◽  
Vol 223 (1) ◽  
pp. 10-14 ◽  
Author(s):  
Sarah M Hicks ◽  
Kai Pohl ◽  
Teresa Neeman ◽  
Hayley A McNamara ◽  
Kate M Parsons ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Confidence Interval ◽  
Sensitivity And Specificity ◽  
Immunosorbent Assay ◽  
Elective Surgery ◽  
Enzyme Linked Immunosorbent Assay ◽  
Receptor Binding Domain ◽  
Assay Sensitivity ◽  
Specific Antibodies ◽  
Transmission Setting

Abstract Estimates of seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies have been hampered by inadequate assay sensitivity and specificity. Using an enzyme-linked immunosorbent assay–based approach that combines data about immunoglobulin G responses to both the nucleocapsid and spike receptor binding domain antigens, we show that excellent sensitivity and specificity can be achieved. We used this assay to assess the frequency of virus-specific antibodies in a cohort of elective surgery patients in Australia and estimated seroprevalence in Australia to be 0.28% (95% Confidence Interval, 0–1.15%). These data confirm the low level of transmission of SARS-CoV-2 in Australia before July 2020 and validate the specificity of our assay.

scholarly journals Comparison of a New Immunochromatographic Test to Enzyme-Linked Immunosorbent Assay for Rapid Detection of Immunoglobulin M Antibodies to Hepatitis E Virus in Human Sera

2005 ◽  
Vol 12 (5) ◽  
pp. 593-598 ◽  
Author(s):  
Hsiao Ying Chen ◽  
Yang Lu ◽  
Teresa Howard ◽  
David Anderson ◽  
Priscilla Yiquan Fong ◽  
...  
Keyword(s):  
Acute Hepatitis ◽  
Immunosorbent Assay ◽  
Predictive Value ◽  
Rapid Detection ◽  
Hepatitis E Virus ◽  
Rapid Test ◽  
Hepatitis E ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immunochromatographic Test ◽  
Acute Hepatitis E

ABSTRACT An immunochromatographic test for rapid detection of IgM antibodies in patients with acute hepatitis E infection was developed utilizing the well-characterized recombinant protein EP2.1 and monoclonal antibody 4B2. The new rapid test based on a novel reverse-flow technology was able to generate a positive result within 2 to 3 min. Our study showed that this test was able to detect anti-HEV IgM antibodies in 96.7% of the patient samples tested (n = 151) while maintaining an excellent specificity of 98.6% with samples from various patient or healthy control groups (total n = 208). Furthermore, this rapid test gave a good specificity of 90.9% when tested with rheumatoid factor (RF)-positive sera (RF value of ≤850 IU/ml; n = 11) although a higher concentration of RF in samples might cause cross-reactivity. The new test has a good agreement of 97.2% with a kappa value of 0.943 when compared with a reference enzyme-linked immunosorbent assay. The positive predictive value and the negative predictive value for the rapid test thus reached 98.0 and 97.6%, respectively. This is the first rapid, point-of-care test for hepatitis E and will be especially useful for the diagnosis of acute hepatitis E virus infection in field and emergency settings and in resource-poor countries.

scholarly journals Recombinant Protein-Based Enzyme-Linked Immunosorbent Assay and Immunochromatographic Tests for Detection of Immunoglobulin G Antibodies to Severe Acute Respiratory Syndrome (SARS) Coronavirus in SARS Patients

2004 ◽  
Vol 11 (2) ◽  
pp. 287-291 ◽  
Author(s):  
Ming Guan ◽  
Hsiao Ying Chen ◽  
Shen Yun Foo ◽  
Yee-Joo Tan ◽  
Phuay-Yee Goh ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Recombinant Proteins ◽  
Immunosorbent Assay ◽  
Immunoglobulin G ◽  
Predictive Value ◽  
Rapid Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Kappa Value ◽  
Sensitivity Specificity

ABSTRACT An enzyme-linked immunosorbent assay (ELISA) and a rapid immunochromatographic test for detection of immunoglobulin G (IgG) antibodies in severe acute respiratory syndrome (SARS) patients were developed by utilizing the well-characterized recombinant proteins Gst-N and Gst-U274. The ELISA detected IgG antibodies to SARS-CoV in all 74 convalescent-phase samples from SARS patients while weakly cross-reacting to only 1 of the 210 control sera from healthy donors. This finding thus led to a kit sensitivity, specificity, and accuracy of 100, 99.5, and 99.6%, respectively. The test thus provided a positive predictive value (PPV) of 98.7% and a negative predictive value (NPV) of 100%. In addition, the ELISA gave a positive delta of 5.4 and a negative delta of 3.6, indicating an excellent differentiation between positives and negatives. The same recombinant proteins were also applied to a newly developed platform for the development of a 15-min rapid test. The resulting rapid test has an excellent agreement of 99.6%, with a kappa value of 1.00, with the ELISA. Again, this rapid test was able to detect 100% of the samples tested (n = 42) while maintaining a specificity of 99.0% (n = 210). The PPV and NPV for the rapid test thus reached 95.3 and 100%, respectively.

Alterations in Vascular Endothelial Cell-related Plasma Proteins In Thalassaemic Patients and their Correlation with Clinical Symptoms

1995 ◽  
Vol 74 (04) ◽  
pp. 1045-1049 ◽  
Author(s):  
P Butthep ◽  
A Bunyaratvej ◽  
Y Funahara ◽  
H Kitaguchi ◽  
S Fucharoen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Immunosorbent Assay ◽  
Plasma Proteins ◽  
Clinical Symptoms ◽  
Vascular Endothelial Cells ◽  
Vascular Endothelial Cell ◽  
Enzyme Linked Immunosorbent Assay ◽  
Vascular Endothelial ◽  
Leg Ulcers

SummaryAn increased level of plasma thrombomodulin (TM) in α- and β- thalassaemia was demonstrated using an enzyme-linked immunosorbent assay (ELISA). Nonsplenectomized patients with β-thalassaemia/ haemoglobin E (BE) had higher levels of TM than splenectomized cases (BE-S). Patients with leg ulcers (BE-LU) were found to have the highest increase in TM level. Appearance of larger platelets in all types of thalassaemic blood was observed indicating an increase in the number of younger platelets. These data indicate that injury of vascular endothelial cells is present in thalassaemic patients.

Multicolor enzyme-linked immunoassay method for visual readout of carbendazim

2021 ◽  
Author(s):  
Haoran Liu ◽  
Yiwen Wang ◽  
Ruijie Fu ◽  
Jing Zhou ◽  
Yanlin Liu ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
High Specificity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Specificity And Sensitivity

Enzyme-linked immunosorbent assay (ELISA) with high specificity and sensitivity is one of the most popular techniques for detecting carbendazim (CBD), a commonly used benzimidazole fungicide in agriculture. However, the traditional...

scholarly journals Analysis of Specific Immunoglobulin G Subclass Antibodies for Serological Diagnosis of Echinococcosis by a Standard Enzyme-Linked Immunosorbent Assay

1998 ◽  
Vol 5 (5) ◽  
pp. 613-616 ◽  
Author(s):  
Felix Grimm ◽  
Friedrich E. Maly ◽  
Jian Lü ◽  
Roberto Llano
Keyword(s):  
Healthy Volunteers ◽  
Immunosorbent Assay ◽  
Immunoglobulin G ◽  
Serological Diagnosis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Parasitic Infections ◽  
Igg Subclass ◽  
Specific Antibodies ◽  
Specific Igg4 ◽  
Antibody Levels

ABSTRACT The potential roles of specific antibodies of the different immunoglobulin G (IgG) subclasses in the serological diagnosis of cystic echinococcosis (CE) and alveolar echinococcosis (AE) were investigated by an enzyme-linked immunosorbent assay based on hydatid fluid as antigen. Specific antibodies of subclass 1 were found to be of major importance. In sera collected at the time of diagnosis (i.e., before any therapeutic intervention was initiated) they could be demonstrated in 14 of 15 sera from patients with CE and in all 12 sera from patients with AE. The most discriminatory and the most specific antibodies found in this study belonged to IgG subclass 4. Only one false-positive reaction was observed with 253 sera from healthy volunteers, and no cross-reactions occurred in 80 sera from patients with different parasitic infections. Specific IgG4 antibodies could be demonstrated in 61.0 to 66.7% (CE) or 47.6 to 66.7% (AE) of the cases. Antibody levels of IgG subclass 2 were elevated only moderately, and subclass 3 antibodies were detected in a few cases only. In addition, nonspecific reactions in sera of healthy volunteers or patients with other parasitic infections could partially be attributed to antibodies of subclasses 2 and 3.

scholarly journals Interpretations of Antibody Responses toSalmonella enterica Serotype Enteritidis gm Flagellin in Poultry Flocks Are Enhanced by a Kinetics-Based Enzyme-Linked Immunosorbent Assay

1998 ◽  
Vol 5 (4) ◽  
pp. 550-555 ◽  
Author(s):  
Patrick L. McDonough ◽  
Richard H. Jacobson ◽  
John F. Timoney ◽  
Ahmed Mutalib ◽  
David C. Kradel ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
High Sensitivity ◽  
High Specificity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Analytical Sensitivity ◽  
Department Of Agriculture ◽  
Trace Back ◽  
Elisa Format ◽  
Commercial Poultry ◽  
Computer Controlled

ABSTRACT Many regulatory and diagnostic programs for the detection ofSalmonella enterica serotype Enteritidis infection in commercial poultry flocks have relied on rapid Pullorum agglutination tests to screen birds because of the shared antigens of S. enterica Enteritidis and S. enterica Pullorum and Gallinarum; however, the use of the enzyme-linked immunosorbent assay (ELISA) format affords better analytical sensitivity than crude agglutination tests. In this study, we adapted our earlier conventional indirect ELISA, using gm flagellin as the antigen, to a kinetics-based, computer-controlled ELISA (KELA). The KELA was used to screen for flagellin antibody from three commercial flocks: (i) a large flock involved in a U.S. Department of Agriculture trace back from a humanS. enterica Enteritidis foodborne outbreak (n = 3,209), (ii) a flock infected with the endemicS. enterica Enteritidis serotype but which also had multiple other salmonella serotypes (n = 65), and (iii) an S. enterica Pullorum-infected flock (n = 12). The first flock (S. entericaEnteritidis prevalence of 2.45% based on culture) provided a field test of the KELA and allowed the calculation of diagnostic sensitivity (D-Sn) and diagnostic specificity (D-Sp). With a cutoff of 10 (used for screening flocks [i.e., high sensitivity]), the KELA has a D-Sn of 95.2% and a D-Sp of 18.5%; with a cutoff of 140 (used in confirmatory flock testing [i.e., high specificity]), the KELA has a D-Sn of 28.0% and a D-Sp of 99.1%. We found that with a cutoff of 60 (D-Sn = 63.1%; D-Sp = 91.6%), we could eliminate reactions in the KELA caused by other non-S. enterica Enteritidis salmonellae. The KELA was also compared to two commercial rapid Pullorum tests, the Solvay (D-Sn = 94.9%; D-Sp = 55.5%) and the Vineland (D-Sn = 62.0%; D-Sp = 75.3%).

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