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.

scholarly journals Double-Antigen Enzyme-Linked Immunosorbent Assay for Detection of Hepatitis E Virus-Specific Antibodies in Human or Swine Sera

2008 ◽  
Vol 15 (8) ◽  
pp. 1151-1157 ◽  
Author(s):  
Wei Ping Hu ◽  
Yang Lu ◽  
Nestor Amadeo Precioso ◽  
Hsiao Ying Chen ◽  
Teresa Howard ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Predictive Value ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Specific Antibodies ◽  
Kappa Value ◽  
Healthy Control ◽  
The Individual

ABSTRACT A new double-antigen sandwich-based enzyme-linked immunosorbent assay (ELISA) for the detection of total antibodies (immunoglobulin G [IgG] and IgM) specific for hepatitis E virus (HEV) was developed by utilizing well-characterized recombinant protein ET2.1 and its peroxidase-labeled counterpart. Our study showed that the ELISA detected all the positive patient samples (n = 265) regardless of whether they contained IgM or IgG antibodies, or both, while it maintained an excellent specificity of 98.8% with samples from various patient or healthy control groups (total number of samples, 424). The test had a detection limit for anti-HEV IgG antibodies that was equivalent to 62 mIU/ml of the international reference. Compared with the serological status of the specimens determined on the basis of tests performed at the individual collection sites, the testing outcome generated by the new ELISA had a good agreement of 99.3%, with a kappa value of 0.985. The positive predictive value and the negative predictive value for the new test reached 98.1% and 100%, respectively. This ELISA had a positive delta value of 4.836 and a negative delta value of 3.314 (where delta is a measure of the number of standard deviations by which the cutoff is separated from the mean of the sample groups) (N. Crofts, W. Maskill, and I. D. Gust, J. Virol. Methods 22:51-59, 1988), indicating that it had an excellent ability to differentiate the infected and noninfected cohorts. Furthermore, the new design enables the detection of antibodies not only in human samples but also in pig samples. Our preliminary data showed that the ELISA could detect seroconversion in samples from pigs at as early as 14 days postinoculation. The potential utility of detecting specific antibodies in pigs will be an added advantage for managing the disease, with suggested zoonotic implications.

scholarly journals Evaluation of a Novel Enzyme-Linked Immunosorbent Assay To Detect Immunoglobulin G Antibody to Enolase for Serodiagnosis of Invasive Candidiasis

2007 ◽  
Vol 14 (3) ◽  
pp. 318-319 ◽  
Author(s):  
Ana Laín ◽  
María D. Moragues ◽  
Juan Carlos García Ruiz ◽  
Joaquín Mendoza ◽  
Ana Camacho ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Immunosorbent Assay ◽  
Immunoglobulin G ◽  
Invasive Candidiasis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Predictive Values ◽  
Sensitivity Specificity ◽  
Immunocompetent Patients

ABSTRACT The performance of a new test to detect antibodies to Candida albicans recombinant enolase was investigated in 47 immunocompromised and 51 immunocompetent patients. The sensitivity, specificity, and positive and negative predictive values of the test for the diagnosis of invasive candidiasis were 81.0, 83.9, 79.1, and 85.5%, respectively.

scholarly journals Comparison of an IgG-Specific Enzyme-Linked Immunosorbent Assay Cutoff of 0.4 Versus 0.8 and 1.0 Optical Density Units for Heparin-Induced Thrombocytopenia

2016 ◽  
Vol 23 (3) ◽  
pp. 282-286 ◽  
Author(s):  
Brianne M. Ritchie ◽  
Jean M. Connors ◽  
Katelyn W. Sylvester
Keyword(s):  
Optical Density ◽  
Immunosorbent Assay ◽  
Predictive Value ◽  
Retrospective Chart Review ◽  
Serotonin Release ◽  
Enzyme Linked Immunosorbent Assay ◽  
Platelet Factor ◽  
Heparin Induced Thrombocytopenia ◽  
Institutional Review ◽  
Sensitivity Specificity

Background: Previous studies have demonstrated optimized diagnostic accuracy in utilizing higher antiheparin–platelet factor 4 (PF4) enzyme-linked immunosorbent assay (ELISA) optical density (OD) thresholds for diagnosing heparin-induced thrombocytopenia (HIT). We describe the incidence of positive serotonin release assay (SRA) results, as well as performance characteristics, for antiheparin–PF4 ELISA thresholds ≥0.4, ≥0.8, and ≥1.0 OD units in the diagnosis of HIT at our institution. Methods: Following institutional review board approval, we conducted a single-center retrospective chart review on adult inpatients with a differential diagnosis of HIT evaluated by both antiheparin–PF4 ELISA and SRA from 2012 to 2014. The major endpoints were to assess incidence of positive SRA results, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy at antiheparin–PF4 ELISA values ≥0.4 OD units when compared to values ≥0.8 and ≥1.0 OD units. Clinical characteristics, including demographics, laboratory values, clinical and safety outcomes, length of stay, and mortality, were collected. Results: A total of 140 patients with 140 antiheparin–PF4 ELISA and SRA values were evaluated, of which 23 patients were SRA positive (16.4%) and 117 patients were SRA negative (83.6%). We identified a sensitivity of 91.3% versus 82.6% and 73.9%, specificity of 61.5% versus 87.2% and 91.5%, PPV of 31.8% versus 55.9% and 63.0%, NPV of 97.3% versus 96.2% and 94.7%, and accuracy of 66.4% versus 86.4% and 88.6% at antiheparin–PF4 ELISA thresholds ≥0.4, ≥0.8, and ≥1.0 OD units, respectively. Conclusion: Our study suggests an increased antiheparin–PF4 ELISA threshold of 0.8 or 1.0 OD units enhances specificity, PPV, and accuracy while maintaining NPV with decreased sensitivity.

Agreement of Enzyme-Linked Immunosorbent Assay With Rapid Plasma Reagin and Treponema pallidum Hemagglutination Assay for Screening and Diagnosis of Syphilis at National Blood Bank Service in Addis Ababa, Ethiopia

2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S153-S154
Author(s):  
Jemal Ibrahim ◽  
Ejigayehu Afework ◽  
Mintewab Hussein
Keyword(s):  
Positive Predictive Value ◽  
Predictive Value ◽  
Addis Ababa ◽  
Treponema Pallidum ◽  
Blood Bank ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rapid Plasma Reagin ◽  
Hemagglutination Assay ◽  
Kappa Value ◽  
Sensitivity Specificity

Abstract Objectives To determine the agreement of enzyme-linked immunosorbent assay (ELISA) with rapid plasma reagin (RPR) and Treponema pallidum hemagglutination assay (TPHA) at the National Blood Bank Service in Addis Ababa, Ethiopia. Methods The study was conducted from January to June 2016 on 190 syphilis ELISA positive and 190 negative samples stored at the National Blood Bank Service (NBBS) laboratory, Addis Ababa, Ethiopia, from July 2015 to December 2015. A systematic random sampling method was used to select samples. The data were analyzed by SPSS version 20 software. The overall percent agreement, kappa value, sensitivity, specificity, positive predictive value, and negative predictive value of the tests were calculated. Results From 190 positive sera, 151 (80%) were confirmed as positive by TPHA, and 39 (20%) were found false positive; 59 (31.1%) of them were positive and 131 (68.9%) were false positive by RPR. From 190 negative sera, all were negative by RPR and TPHA. The sensitivity, specificity, positive predictive value, and negative predictive value of TPHA were 99.9%, 85%, 79%, and 100%, respectively, while RPR was 62%, 99%, 100%, and 63%, respectively. Overall percent agreement of ELISA with TPHA was 90% and corresponding kappa value was 0.795, and ELISA with RPR was 66% with a kappa value of 0.375. Conclusion TPHA was very sensitive; there was substantial agreement with ELISA. Whereas RPR was highly specific and less sensitive, there was fair agreement with ELISA. TPHA can be used interchangeably with ELISA to screen blood in blood bank laboratories.

scholarly journals Evaluation of Immunoglobulin G Subclass Antibodies against Recombinant Fasciola gigantica Cathepsin L1 in an Enzyme-Linked Immunosorbent Assay for Serodiagnosis of Human Fasciolosis

2005 ◽  
Vol 12 (10) ◽  
pp. 1152-1156 ◽  
Author(s):  
Chaisiri Wongkham ◽  
Chairat Tantrawatpan ◽  
Pewpan M. Intapan ◽  
Wanchai Maleewong ◽  
Sopit Wongkham ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Immunoglobulin G ◽  
Fasciola Gigantica ◽  
Enzyme Linked Immunosorbent Assay ◽  
Parasitic Infections ◽  
Predictive Values ◽  
Diagnostic Potential ◽  
Diagnostic Values ◽  
Sensitivity Specificity ◽  
Igg4 Antibody

ABSTRACT A cystatin capture enzyme-linked immunosorbent assay (ELISA) using recombinant Fasciola gigantica cathepsin L1 antigen was developed to detect specific immunoglobulin G (IgG) subclass antibodies (IgG1, IgG2, IgG3, and IgG4) and was evaluated for its diagnostic potential for human fasciolosis. In an analysis of the sera of 13 patients infected with F. gigantica, 209 patients with other parasitic infections, 32 cholangiocarcinoma patients, and 42 healthy controls, the IgG4-ELISA gave the highest diagnostic values. The sensitivity, specificity, accuracy, and positive and negative predictive values of this method based on the detection of IgG4 antibody were 100%, 99.3%, 99.3%, 86.7%, and 100%, respectively. The results revealed that restricting the ELISA to the detection of specific IgG4 antibody enhanced the specificity and accuracy for the serodiagnosis of human fasciolosis.

scholarly journals Serum Immunoglobulin G Antibody Responses to Bordetella pertussis Lipooligosaccharide and B.parapertussis Lipopolysaccharide in Children with Pertussis and Parapertussis

2001 ◽  
Vol 8 (5) ◽  
pp. 1015-1017 ◽  
Author(s):  
Birger Trollfors ◽  
Teresa Lagergård ◽  
John Taranger ◽  
Elisabet Bergfors ◽  
Rachel Schneerson ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Bordetella Pertussis ◽  
Immunoglobulin G ◽  
Antibody Responses ◽  
Serum Immunoglobulin ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Bordetella Parapertussis ◽  
The Individual

ABSTRACT Serum immunoglobulin G (IgG) antibodies against the lipooligosaccharide (LOS) of Bordetella pertussis and the lipopolysaccharide (LPS) of Bordetella parapertussiswere measured by enzyme-linked immunosorbent assay in paired sera from 40 children with pertussis and 14 with parapertussis. Wide differences in the individual responses were noted. Both anti-LOS and -LPS IgG levels increased significantly in the children with pertussis, as did anti-LPS but not anti-LOS in those with parapertussis.

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 Antibody Detection and Dynamic Characteristics in Patients With Coronavirus Disease 2019

2020 ◽  
Vol 71 (8) ◽  
pp. 1930-1934 ◽  
Author(s):  
Fei Xiang ◽  
Xiaorong Wang ◽  
Xinliang He ◽  
Zhenghong Peng ◽  
Bohan Yang ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Symptom Onset ◽  
Predictive Value ◽  
Immunoglobulin M ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Great Specificity ◽  
Sensitivity Specificity ◽  
Consistency Rate

Abstract Background The coronavirus disease 2019 (COVID-19), caused by infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been rapidly spreading nationwide and abroad. A serologic test to identify antibody dynamics and response to SARS-CoV-2 was developed. Methods The antibodies against SARS-CoV-2 were detected by an enzyme-linked immunosorbent assay based on the recombinant nucleocapsid protein of SARS-CoV-2 in patients with confirmed or suspected COVID-19 at 3–40 days after symptom onset. The gold standard for COVID-19 diagnosis was nucleic acid testing for SARS-CoV-2 by real-time reverse-transcription polymerase chain reaction (rRT-PCR). The serodiagnostic power of the specific immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies against SARS-CoV-2 was investigated in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and consistency rate. Results The seroconversion of specific IgM and IgG antibodies were observed as early as the fourth day after symptom onset. In the patients with confirmed COVID-19, sensitivity, specificity, PPV, NPV, and consistency rate of IgM were 77.3% (51/66), 100%, 100%, 80.0%, and 88.1%, respectively, and those of IgG were 83.3% (55/66), 95.0%, 94.8%, 83.8%, and 88.9%. In patients with suspected COVID-19, sensitivity, specificity, PPV, NPV, and consistency rate of IgM were 87.5% (21/24), 100%, 100%, 95.2%, and 96.4%, respectively, and those of IgG were 70.8% (17/24), 96.6%, 85.0%, 89.1%, and 88.1%. Both antibodies performed well in serodiagnosis for COVID-19 and rely on great specificity. Conclusions The antibodies against SARS-CoV-2 can be detected in the middle and later stages of the illness. Antibody detection may play an important role in the diagnosis of COVID-19 as a complementary approach to viral nucleic acid assays.

scholarly journals A Quantitative ELISA Protocol for Detection of Specific Human IgG Against the SARS-CoV-2 Spike Protein

Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 770
Author(s):  
Rémi Vernet ◽  
Emily Charrier ◽  
Julien Grogg ◽  
Nicolas Mach
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Immunosorbent Assay ◽  
Spike Protein ◽  
Quantitative Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Human Igg ◽  
Microtiter Plates ◽  
Global Priority ◽  
Humoral Responses

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a worldwide pandemic with at least 3.8 million deaths to date. For that reason, finding an efficient vaccine for this virus quickly became a global priority. The majority of vaccines now marketed are based on the SARS‑CoV‑2 spike protein that has been described as the keystone for optimal immunization. In order to monitor SARS‑CoV‑2 spike-specific humoral responses generated by immunization or infection, we have developed a robust and reproducible enzyme-linked immunosorbent assay (ELISA) protocol. This protocol describes a method for quantitative detection of IgG antibodies against the SARS‑CoV‑2 spike protein using antigen-coated microtiter plates. Results showed that antibodies could be quantified between the range of 1.953 ng/mL to 500 ng/mL with limited inter- and intra-assay variability.

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.

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