scholarly journals LB-15. A Trans-Governmental Collaborative Effort to Independently Evaluate SARS-CoV-2 Serology Assays Using Well-Characterized Sample Panels

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S851-S851
Author(s):  
Ribhi Shawar ◽  
Brendan O’Leary ◽  
Troy Kemp ◽  
James Cherry ◽  
S Michele Owen ◽  
...  
Keyword(s):  
Positive Result ◽  
National Laboratory ◽  
Nucleic Acid Amplification ◽  
Enzyme Linked Immunosorbent Assay ◽  
Plasma Samples ◽  
Serum Samples ◽  
Antibody Titers ◽  
Antibody Class ◽  
Novel Coronavirus ◽  
Regulatory Decisions

Abstract Background The emergence of the novel coronavirus, SARS-CoV-2, created a crucial need for accurate tests for diagnosis, assessment of prior infection, and understanding its natural history. Serology assays play an important role in the assessment of anti-viral immune responses and previous infections. Evaluation of serology assays with well-characterized serum and/or plasma samples is critical to determine assay performance. CDC, FDA and NCI’s Frederick National Laboratory for Cancer Research (NCI-FNLCR) have established a collaborative network to independently evaluate commercial antibody tests prior to their authorization. Methods Positive (n=30) serum samples with a range of anti-SARS-CoV-2 antibody titers (Table) and negative (n=80) serum and/or plasma samples were selected to establish performance evaluation panels (PEVs). Three PEVs with similar overall antibody titer distribution have been created. Negative samples were collected prior to 2020, before the SARS-CoV-2 pandemic. Positive samples were from patients previously confirmed to have SARS-CoV-2 using a nucleic acid amplification test. Each sample was characterized at CDC and NCI-FNLCR for presence/absence of SARS-CoV-2 IgM and IgG antibodies using a SARS-CoV-2 spike enzyme linked immunosorbent assay (ELISA). NCI-FNLCR also performed a SARS-CoV-2 spike Receptor Binding Domain (RBD) IgG ELISA. Positive samples were assessed at multiple dilutions. Manufacturers submitted their serology assays for evaluation by this program. The sensitivity of each test was assessed for each antibody class (IgG and IgM) and in a combined manner, where a positive result for either antibody was considered as a positive result. For combined specificity, a negative result meant a sample was negative for both antibodies (IgG and IgM). Number of positive samples with anti-SARS-CoV-2 spike antibodies for each panel (n=30) Results To date, 53 serology assays have been evaluated. Sensitivity ranged from 30.0% to 100% for IgG, from 10.0% to 100% for IgM, and the combined specificity ranged from 57.5% to 100%. For 2 assays that measure total Ig, sensitivity was 96.7% and 100%. Conclusion This program completed over 50 performance evaluations with well-characterized PEVs. Results have been used to inform FDA regulatory decisions and are publicly available on FDA’s website. Disclosures Cristina Cassetti, PhD, Nothing to disclose

scholarly journals Serological Evaluation of Specific-Antibody Levels in Patients Treated for Chronic Chagas' Disease

2007 ◽  
Vol 15 (2) ◽  
pp. 297-302 ◽  
Author(s):  
Olga Sánchez Negrette ◽  
Fernando J. Sánchez Valdéz ◽  
Carlos D. Lacunza ◽  
María Fernanda García Bustos ◽  
María Celia Mora ◽  
...  
Keyword(s):  
Chagas Disease ◽  
Treatment Effectiveness ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Serological Tests ◽  
Recombinant Antigens ◽  
Antibody Titers ◽  
Laboratory Procedures ◽  
The Individual ◽  
Antibody Levels

ABSTRACT Serological tests are the main laboratory procedures used for diagnosis during the indeterminate and chronic stages of Chagas' disease. A serological regression to negativity is the main criterion used to define parasitological cure in treated patients. The aim of this work was to monitor the individual specificities of antibody levels for 3 years posttreatment in 18 adult patients. Conventional serological techniques (hemagglutination assays and enzyme-linked immunosorbent assay [ELISA]) were modified by using recombinant antigens to detect early markers of treatment effectiveness. For this purpose, serum samples were taken before and during treatment and every 6 months after treatment for at least 3 years. When hemagglutination assays were used, a decrease in antibody levels was observed in only one patient. When ELISA with serum dilutions was used, antibody clearance became much more apparent: in 77.7% (14/18) of the patients, antibody titers became negative with time. This was observed at serum dilutions of 1/320 and occurred between the 6th and the 30th months posttreatment. The immune response and the interval for a serological regression to negativity were different for each patient. For some of the recombinant antigens, only 50% (9/18) of the patients reached the serological regression to negativity. Recombinant antigen 13 might be a good marker of treatment effectiveness, since 66.6% (six of nine) of the patients presented with an early regression to negativity for specific antibodies to this antigen (P = 0.002).

scholarly journals Immunologic aspect in diagnosis and treatment of SARS-COV-2 patients

2020 ◽  
Vol 3 (2) ◽  
pp. 113-121
Author(s):  
Sumaiya Yasin ◽  
Theophilus Bhatti ◽  
Muhammad Umer Farooqi ◽  
Farrukh Mateen
Keyword(s):  
Therapeutic Option ◽  
Lung Epithelial Cells ◽  
Confirmatory Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Nasopharyngeal Swab ◽  
Angiotensin Converting Enzyme 2 ◽  
Antibody Titers ◽  
Novel Coronavirus ◽  
Available Information ◽  
Respiratory Droplets

Recent worldwide outbreak of novel coronavirus disease (CoVID-19) has affected massive human population including Pakistan, and has caused a huge number of mortalities in few months. CoVID-19 is an infectious disease caused by a virus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) which is single stranded RNA enveloped beta coronavirus and affects lower respiratory tract. It transmits from human to human through respiratory droplets. It uses its S-protein to recognize ACE2 (Angiotensin Converting Enzyme-2) receptors in lung epithelial cells where it attaches and causes infection. The incubation period is 2-14 days. In pre-symptomatic phase, body’s immune system starts antibodies production. Significant antibodies are IgM and IgG that produces within 03-06 days and 8-12 days respectively. This review provides the available information about immunological aspects in terms of diagnosis and screening of CoVID-19 and potential therapeutic targets for combating SARS-CoV-2 infection. Immunologic techniques to detect these antibodies are ELISA (Enzyme-linked Immunosorbent Assay), CMIA (Chemiluminescent Micro particle Immunoassay) and ICT (Immunochromatographic Test). Among these, ELISA and CMIA are found to be highly specific and sensitive in convalescent phase of infection. While the fundamental confirmatory test for SARS-CoV-2 infection is RT-PCR (Reverse Transcription Polymerase Chain Reaction) which detects the viral RNA in respiratory samples preferably nasopharyngeal swab. Serological assays are essential to find out rate of infection, and most importantly antibody titers in recovered patients to be used for therapeutic purpose. After some successful studies Convalescent Plasma is considered as a good therapeutic option in the absence of specific antiviral therapy.

scholarly journals Development of a Smartphone-Based Nanozyme-Linked Immunosorbent Assay for Quantitative Detection of SARS-CoV-2 Nucleocapsid Phosphoprotein in Blood

2021 ◽  
Vol 12 ◽  
Author(s):  
Bochao Liu ◽  
Ze Wu ◽  
Chaolan Liang ◽  
Jinhui Lu ◽  
Jinfeng Li ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Cross Reactivity ◽  
Quantitative Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Primary Screening ◽  
Global Pandemic ◽  
Novel Coronavirus ◽  
Acid Test ◽  
Control Samples

Since December 2019, a novel coronavirus (SARS-CoV-2) has resulted in a global pandemic of coronavirus disease (COVID-19). Although viral nucleic acid test (NAT) has been applied predominantly to detect SARS-CoV-2 RNA for confirmation diagnosis of COVID-19, an urgent need for alternative, rapid, and sensitive immunoassays is required for primary screening of virus. In this study, we developed a smartphone-based nanozyme-linked immunosorbent assay (SP-NLISA) for detecting the specific nucleocapsid phosphoprotein (NP) of SARS-CoV-2 in 37 serum samples from 20 COVID-19 patients who were diagnosed by NAT previously. By using SP-NLISA, 28/37 (75.7%) serum samples were detected for NP antigens and no cross-reactivity with blood donors’ control samples collected from different areas of China. In a control assay using the conventional enzyme-linked immunosorbent assay (ELISA), only 7/37 (18.91%) serum samples were detected for NP antigens and no cross-reactivity with control samples. SP-NLISA could be used for rapid detection of SARS-CoV-2 NP antigen in primary screening of SARS-CoV-2 infected individuals.

scholarly journals Detection of Anthrax Toxin by an Ultrasensitive Immunoassay Using Europium Nanoparticles

2009 ◽  
Vol 16 (3) ◽  
pp. 408-413 ◽  
Author(s):  
Shixing Tang ◽  
Mahtab Moayeri ◽  
Zhaochun Chen ◽  
Harri Harma ◽  
Jiangqin Zhao ◽  
...  
Keyword(s):  
Protective Antigen ◽  
Lethal Factor ◽  
Laboratory Research ◽  
Enzyme Linked Immunosorbent Assay ◽  
Plasma Samples ◽  
Serum Samples ◽  
Detection Range ◽  
Edema Factor ◽  
Anthrax Lethal Factor ◽  
Europium Nanoparticles

ABSTRACT We developed a europium nanoparticle-based immunoassay (ENIA) for the sensitive detection of anthrax protective antigen (PA). The ENIA exhibited a linear dose-dependent pattern within the detection range of 0.01 to 100 ng/ml and was approximately 100-fold more sensitive than enzyme-linked immunosorbent assay (ELISA). False-positive results were not observed with serum samples from healthy adults, mouse plasma without PA, or plasma samples collected from mice injected with anthrax lethal factor or edema factor alone. For the detection of plasma samples spiked with PA, the detection sensitivities for ENIA and ELISA were 100% (11/11 samples) and 36.4% (4/11 samples), respectively. The assay exhibited a linear but qualitative correlation between the PA injected and the PA detected in murine blood (r = 0.97731; P < 0.0001). Anthrax PA was also detected in the circulation of mice infected with spores from a toxigenic Sterne-like strain of Bacillus anthracis, but only in the later stages of infection. These results indicate that the universal labeling technology based on europium nanoparticles and its application may provide a rapid and sensitive testing platform for clinical diagnosis and laboratory research.

scholarly journals Investigating the Use of Protein Saver Cards for Storage and Subsequent Detection of Bovine Anti-Brucella abortus Smooth Lipopolysaccharide Antibodies and Gamma Interferon

2013 ◽  
Vol 20 (11) ◽  
pp. 1669-1674 ◽  
Author(s):  
Lucy Duncombe ◽  
Nicola J. Commander ◽  
Sevil Erdenlig ◽  
John A. McGiven ◽  
Judy Stack
Keyword(s):  
Blood Serum ◽  
Brucella Abortus ◽  
Room Temperature ◽  
Plasma Samples ◽  
Bovine Blood ◽  
Bovine Brucellosis ◽  
Serum Samples ◽  
Content Type ◽  
Antibody Titers ◽  
Ifn Γ

ABSTRACTBrucella abortus, a smooth strain of the genusBrucella, is the causative agent of bovine brucellosis. To support the ongoing development of diagnostic tests for bovine brucellosis, the use of Protein Saver cards (Whatman) for bovine blood serum and plasma sample collection has been evaluated. These cards offer significant logistical and safety alternatives to transporting and storing liquid samples and may aid in diagnostic programs and validation studies. To evaluate the utility of these cards, 204 bovine blood serum samples fromBrucella-infected and noninfected animals were stored on and eluted from the Protein Saver cards. Anti-Brucellasmooth lipopolysaccharide (sLPS) antibody titers for the serum eluates were compared to those of the unprocessed original serum samples by indirect enzyme-linked immunosorbent assay (ELISA). The results showed a highly significant correlation between titers from the serum eluates and the unprocessed sera. Therefore, under these circumstances, serum eluates and unprocessed serum samples may be used interchangeably. Blood plasma from 113 mitogen-stimulated whole-blood samples was added to and eluted from the Protein Saver cards. The gamma interferon (IFN-γ) titers in the plasma eluates were compared to those of the unprocessed plasma samples obtained by IFN-γ ELISA. The results showed a significant correlation between the plasma eluates and the unprocessed plasma samples. To derive a signal in the plasma eluate, it was necessary to develop a novel and highly sensitive ELISA for the detection of IFN-γ. The serum samples stored on cards at room temperature over a 10-day period showed little variation in antibody titers. However, the plasma eluates showed a progressive loss of IFN-γ recovery over 10 days when stored at room temperature.

scholarly journals Evaluation of Enzyme-Linked Immunoassay and Colloidal Gold-Immunochromatographic Assay Kit for Detection of Novel Coronavirus (SARS-Cov-2) Causing an Outbreak of Pneumonia (COVID-19)

2020 ◽  
Author(s):  
Jie Xiang ◽  
Mingzhe Yan ◽  
Hongze Li ◽  
Ting Liu ◽  
Chenyao Lin ◽  
...  
Keyword(s):  
Colloidal Gold ◽  
Laboratory Diagnosis ◽  
Immunochromatographic Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Healthy Controls ◽  
Plasma Samples ◽  
Igg Antibodies ◽  
Significant Difference ◽  
Novel Coronavirus ◽  
Treatment Pressure

AbstractBACKGROUNDIn December 2019, a novel coronavirus (SARS-CoV-2)–infected pneumonia (COVID-19) occurred in Wuhan, China. Travel-associated cases have also been reported in other countries. The number of cases has increased rapidly but laboratory diagnosis is limited.METHODSWe collect two groups of cases diagnosed with COVID-19 for experiments. One group collected 63 samples for Enzyme-linked immunosorbent assay (ELISA) IgG and IgM antibodies. The other group collected 91 plasma samples for colloidal gold-immunochromatographic assay (GICA).RESULTSThe sensitivity of the combined ELISA IgM and ELISA IgG detection was 55/63 ( 87.3%), The sensitivity of the combined GICA IgM and GICA IgG detection was 75/91 ( 82.4%), Both methods are negative for healthy controls, specificity of 100%. There is no significant difference between the sensitivity of between ELISA and GICA (IgM+ IgG).CONCLUSIONSELISA and GICA for specific IgM and IgG antibodies are conventional serological assays, they are simple, fast, and safe, the results can be used for clinical reference, and the huge clinical diagnosis and treatment pressure can be greatly relieved.

scholarly journals Expression of Antibodies Directed to Paracoccidioides brasiliensis Glycosphingolipids during the Course of Paracoccidioidomycosis Treatment

2006 ◽  
Vol 14 (2) ◽  
pp. 150-156 ◽  
Author(s):  
Silvio Bertini ◽  
Arnaldo L. Colombo ◽  
Helio K. Takahashi ◽  
Anita H. Straus
Keyword(s):  
Immune Response ◽  
Paracoccidioides Brasiliensis ◽  
Immunoglobulin M ◽  
Antifungal Treatment ◽  
Primary Immune Response ◽  
Enzyme Linked Immunosorbent Assay ◽  
Carbohydrate Structure ◽  
Dimorphic Fungus ◽  
Serum Samples ◽  
Antibody Titers

ABSTRACT Paracoccidioidomycosis (PCM) is a granulomatous disease caused by the dimorphic fungus Paracoccidioides brasiliensis. The immunoglobulin classes and isotypes of antibodies directed to acidic glycosphingolipids (GSLs) and glucosylceramide of P. brasiliensis were determined by enzyme-linked immunosorbent assay of sera from 31 PCM patients. The reactivities of 38 serum samples were analyzed by considering the stage of treatment: before antifungal treatment (n = 10), during 1 to 4 months of treatment (T1-4; n = 9), during 5 to 12 months of treatment (T5-12; n = 9), and posttreatment (PT; n = 10). Sera from healthy subjects (n = 12) were used as controls. Only the GSL Pb-1 antigen, which presents the carbohydrate structure Galfβ1-6(Manα1-3)Manβ1, was reactive with the PCM patient sera. The PCM patient sera did not react with Pb-2, which lacks the Galf residue and which is considered the biosynthetic precursor of Pb-1, indicating that the Galf residue is essential for antibody reactivity. The Pb-1 glycolipid from nontreated patients elicited a primary immune response with immunoglobulin M (IgM) production and subsequent switching to IgG1 production. The IgG1 titer increased after the start of antifungal treatment (T1-4 group), and general decreases in the anti-Pb-1 antibody titers were observed after 5 months of treatment (T5-12 and PT groups). The Pb-1 antigen, an acidic GSL with terminal Galf residue, has potential application as an elicitor of the host immune response in patients with PCM.

scholarly journals Use of a Dry-Plasma Collection Device to Overcome Problems with Storage and Transportation of Blood Samples for Epidemiology Studies in Developing Countries

2000 ◽  
Vol 7 (6) ◽  
pp. 882-884 ◽  
Author(s):  
Zhannat Z. Nurgalieva ◽  
R. Almuchambetova ◽  
A. Machmudova ◽  
D. Kapsultanova ◽  
Michael S. Osato ◽  
...  
Keyword(s):  
Developing Countries ◽  
Rural Areas ◽  
Relative Sensitivity ◽  
The United States ◽  
Enzyme Linked Immunosorbent Assay ◽  
Plasma Samples ◽  
Serum Samples ◽  
Collection Device ◽  
Epidemiology Studies ◽  
Plasma Collection

ABSTRACT Studies are difficult in areas lacking modern facilities due to the inability to reliably collect, store, and ship samples. Thus, we sought to evaluate the use of a dry plasma collection device for seroepidemiology studies. Plasma was obtained by fingerstick using a commercial dry plasma collection device (Chemcard Plasma Collection Device) and serum (venipuncture) from individuals in Kazakhstan. Plasma samples were air dried for 15 min and then stored desiccated in foil zip-lock pouches at 4 to 6°C and subsequently shipped to the United States by air at ambient temperature. Serum samples remained frozen at −20°C until assayed. Helicobacter pylori status was determined by enzyme-linked immunosorbent assay (HM-CAP EIA) for the dry plasma and the serum samples. The results were concordant in 250 of the 289 cases (86.5%). In 25 cases (8.6%), the dry plasma samples gave indeterminate results and could not be retested because only one sample was collected. Five serum samples were positive, and the corresponding dry plasma samples were negative; one serum sample was negative, and the corresponding plasma sample was positive. The relative sensitivity and specificity of the Chemcard samples to serum were 97.6 and 97.9%, respectively, excluding those with indeterminate results. Repeated freeze-thawing had no adverse effect on the accuracy of the test. We found the dry plasma collection device to provide an accurate and practical alternative to serum when venipuncture may be difficult or inconvenient and sample storage and handling present difficulties, especially for seroepidemiologic studies in rural areas or developing countries and where freeze-thawing may be unavoidable.

scholarly journals COMPARISON OF A RAPID ENZYME-LINKED IMMUNOSORBANT ASSAY TEST WITH AN INDIRECT IMMUNOFLUORESCENT ANTIBODY TEST IN DIAGNOSING EHRLICHIA AND ANAPLASMA INFECTIONS IN DOGS

2019 ◽  
Vol 17 (4) ◽  
pp. 346-352
Author(s):  
Kr. Gospodinova ◽  
G. Zhelev ◽  
V. Petrov
Keyword(s):  
Serum Antibody ◽  
Rapid Test ◽  
Antibody Test ◽  
Diagnostic Value ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Immunofluorescent Antibody ◽  
Antibody Titers ◽  
Indirect Immunofluorescent ◽  
Immunofluorescent Antibody Test

PURPOSE: The objective of this study is to compare the diagnostic value of commercial enzyme-linked immunosorbent assay (ELISA) with indirect immunofluorescent antibody test (IFA) in detecting immunoglobulin-G (IgG) antibodies to Ehrlichia canis and Anaplasma phagocytophilum. METHODS: Seventy-four serum samples, obtained from dogs believed to be naturally infected with E. canis or A. phagocytophilum, were analyzed. RESULTS: By ELISA, 48 (64.9%) samples were found positive for IgG to E. canis, 10 (13.5%) to A. phagocytophilum, 12 (16.2%) to both E. canis and A. phagocytophilum, and in 4 (5.4%) samples no presence of antibodies was detected. The number of serologically positive dogs for IgG was 44 (59.5%) to E. canis, 10 (13.5%) to A. phagocytophilum, 16 (21.6%) to both E. canis and A. phagocytophilum, and 4 (5.4%) were determined negative by means of IFA. In most samples the antibody titer did not exceed 1:80 but in 5 it reached a level of 1:320, and in other 4 of even above 1:640. CONCLUSIONS: This study shows that IFA assay is more sensitive than commercial ELISA rapid test when serum antibody titers are low.

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