scholarly journals Highly Sensitive and Specific SARS-CoV-2 Serological Assay Using a Magnetic Modulation Biosensing System

Biosensors ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Shira Avivi-Mintz ◽  
Yaniv Lustig ◽  
Victoria Indenbaum ◽  
Eli Schwartz ◽  
Amos Danielli
Keyword(s):  
Viral Infections ◽  
Limit Of Detection ◽  
Turnaround Time ◽  
Elisa Test ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Serological Assay ◽  
Clinical Sensitivity ◽  
Highly Sensitive

Sensitive serological assays are needed to provide valuable information about acute and past viral infections. For example, detection of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibodies could serve as the basis for an “immunity passport” that would enable individuals to travel internationally. Here, utilizing a novel Magnetic Modulation Biosensing (MMB) system and the receptor-binding domain of the SARS-CoV-2 spike protein, we demonstrate a highly sensitive and specific anti-SARS-CoV-2 IgG serological assay. Using anti-SARS-CoV-2 IgG antibodies, RT-qPCR SARS-CoV-2-positive and healthy patients’ samples, and vaccinees’ samples, we compare the MMB-based SARS-CoV-2 IgG assay’s analytical and clinical sensitivities to those of the enzyme-linked immunosorbent assay (ELISA). Compared with ELISA, the MMB-based assay has an ~6-fold lower limit of detection (129 ng/L vs. 817 ng/L), and it detects an increase in the IgG concentration much earlier after vaccination. Using 85 RT-qPCR SARS-CoV-2-positive samples and 79 -negative samples, the MMB-based assay demonstrated similar clinical specificity (98% vs. 99%) and sensitivity (93% vs. 92%) to the ELISA test, but with a much faster turnaround time (45 min vs. 245 min). The high analytical and clinical sensitivity, short turnaround time, and simplicity of the MMB-based assay makes it a preferred method for antibody detection.

scholarly journals Effect of multiple freeze-thaw cycles on detection of anti-SARS-CoV-2 IgG antibodies

2021 ◽  
Author(s):  
Farah M. Shurrab ◽  
Duaa W. Al-Sadeq ◽  
Fathima Amanullah ◽  
Salma N. Younes ◽  
Hadeel Al-Jighefee ◽  
...  
Keyword(s):  
Random Effect ◽  
Elisa Test ◽  
Antibody Detection ◽  
P Value ◽  
Elisa Assay ◽  
Igg Antibodies ◽  
Rna Detection ◽  
Freeze Thaw ◽  
Significant Difference ◽  
Number Of Cycles

AbstractSeveral studies have investigated the effect of repeated freeze-thaw (F/T) cycles on RNA detection for SARS-CoV-2. However, no data is available regarding the effect of repeated F/T cycles on SARS-CoV-2 antibody detection in serum. We investigated the effect of multiple F/T cycles on anti-SARS-CoV-2 IgG detection using an ELISA test targeting the nucleocapsid antibodies. Ten positive and one negative SARS-CoV-2 IgG sera from 11 participants, in replicates of five were subjected to a total of 16 F/T cycles and stored at 4°C until tested by ELISA. Statistical analysis was done to test for F/T cycle effect. Non-of the 10 positive sera turned into negative after 16 F/T cycles. There was no significant difference in the OD average reading between the first and last F/T cycles, except for one serum with a minimal decline in the OD. The random-effect linear regression of log (OD) on the number of cycles showed no significant trend with a slope consistent with zero (B=-0.0001; 95% CI −0.0008; 0.0006; p-value=0.781). These results suggest that multiple F/T cycles had no effect on the ability of the ELISA assay to detect the SARS-CoV-2 IgG antibodies.

scholarly journals Investigation of Borrelia burgdorferi antibodies in patients with multiple sclerosis

2020 ◽  
Vol 11 (2) ◽  
pp. 21-24
Author(s):  
Nilay Ildız ◽  
İbrahim Halil Özerol ◽  
A. Cemal Özcan ◽  
Hamit Çelik
Keyword(s):  
Multiple Sclerosis ◽  
Borrelia Burgdorferi ◽  
Viral Infections ◽  
Antibody Test ◽  
Elisa Test ◽  
Igg Antibodies ◽  
Number Of Patients ◽  
Seroprevalence Data ◽  
Significant Difference ◽  
Antibody Positivity

Background: Lyme is a disease that is non-compulsory in our country and whose seroprevalence data is less studied. Aims and Objective: Recent studies have shown that bacterial and viral infections are risk factor for various neurodegenerative diseases such as multiple sclerosis and Alzheimer’s disease. Herein, we aim to determine the seroprevalence of Lyme in multiple sclerosis (MS) patients. For this purpose, 100 MS patient’s serums were investigated for Borrelia burgdorferi IgM and IgG positivity. Materials and Methods: The results identified with ELISA as positive antibody was confirmed by Western Blot (WB) test. The correlation between ages, gender, occupation, tick history, existence of erythema chronicum migrans (ECM), antibody positivity, pain, year with MS results were investigated using Kolmogorov-Smirnow and Kruskal-Wallis statistical test. Results: B. burgdorferi IgM and IgG antibodies were positive in 8% patients when using ELISA method, but that were found to be 2% by WB. ELISA IgM antibody test gave a 5 negative result in WB. These results were considered false positive in the ELISA test. So, altogether 5 patients were positive by WB method. None of syphilis positive samples detected that B. burgdorferi positive serum. A significant difference between the parameters in terms of IgM positivity was not detected (p> 0.05). B. burgdorferi IgG antibodies were found significant differences between the MS disease duration (p = 0.03). MS in the group of less than 10 years had higher titers of IgG antibodies to B. burgdorferi. Conclusion: Although a small number of patients with MS is positive with Lyme antibodies. Lyme disease is a treatable.Also, If the patient is MS, clinician should be considered Lyme in the differential diagnosis. This is the first study that the correlation between Lyme and MS from Turkey.

Detection and Titration of Human Herpesvirus-8–Specific Antibodies in Sera From Blood Donors, Acquired Immunodeficiency Syndrome Patients, and Kaposi's Sarcoma Patients Using a Whole Virus Enzyme-Linked Immunosorbent Assay

Blood ◽  
1998 ◽  
Vol 92 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Louise G. Chatlynne ◽  
William Lapps ◽  
Michael Handy ◽  
Yao Q. Huang ◽  
Rizwan Masood ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Kaposi's Sarcoma ◽  
Blood Donors ◽  
Human Herpesvirus ◽  
Kaposi’S Sarcoma ◽  
Antibody Detection ◽  
Human Herpesvirus 8 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Herpesvirus 8

A human herpesvirus-8 (HHV-8) enzyme-linked immunosorbent assay (ELISA) with a whole virus lysate as antigen was developed and used to measure the seroprevalence rate and levels of IgG antibodies to HHV-8 in sera/plasma of various patient groups and blood donors. The virus antigen was prepared from the KS-1 cell line, which produces lytic virus, and therefore contains a broad array of viral proteins. Seroprevalence studies using this ELISA showed the following: 10 of 91 blood donors (11%) had an average HHV-8 antibody titer of 118; 67 of 72 (93%) classic Kaposi's sarcoma (KS) patients were positive with an average titer of 14,111; and 57 of 62 (92%) KS/human immunodeficiency virus (HIV) patients were positive with an average titer of 4,000. A study on a very limited number of serial serum samples from patients before and after diagnosis with KS showed highly elevated antibody titers to HHV-8 virus after KS lesions developed. Preliminary data show that 50% of the sera from HIV-1+ homosexual patients contain IgG antibodies to HHV-8 suggesting that this population is at high risk for developing KS. Antibody results correlated well with the confirmatory immunofluorescent assays (IFA) using KS-1 cells as the substrate. This HHV-8 IgG antibody detection ELISA is sensitive and specific and does not cross-react with Epstein-Barr virus (EBV) or other human herpesviruses. The results of this HHV-8 antibody survey suggest that this rapid ELISA assay can be used to screen large numbers of sera to find those at risk for developing KS.

scholarly journals Immunoglobulins G, M, and A against Sporothrix schenckii Exoantigens in Patients with Sporotrichosis before and during Treatment with Itraconazole

2007 ◽  
Vol 14 (9) ◽  
pp. 1149-1157 ◽  
Author(s):  
Rodrigo Almeida-Paes ◽  
Monique Amorim Pimenta ◽  
Paulo Cezar F. Monteiro ◽  
Joshua D. Nosanchuk ◽  
Rosely Maria Zancopé-Oliveira
Keyword(s):  
Sporothrix Schenckii ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Number Of Patients ◽  
Highly Sensitive ◽  
Iga Antibodies ◽  
Itraconazole Treatment ◽  
Few Data ◽  
Humoral Responses

ABSTRACT Sporotrichosis is an important subcutaneous mycosis, with an increasing worldwide incidence. However, few data are available regarding the immunological aspects of Sporothrix schenckii infection, particularly the humoral responses to the fungus. In this study we measured immunoglobulin G (IgG), IgM, and IgA in sera from 41 patients with sporotrichosis before antifungal treatment and from another 35 patients with sporotrichosis during itraconazole treatment by using a recently described S. schenckii exoantigen enzyme-linked immunosorbent assay (ELISA). More than 95% of patients had detectable IgA antibodies, and more than 85% had IgM and IgG antibodies before treatment. The number of patients with IgG antibodies increased to 91% during treatment. Conversely, significantly fewer samples from treated patients were positive for IgM (71%) and IgA (89%). Overall, 78% of patients had detectable levels of all isotypes tested at diagnosis, and this percentage dropped to 62.9% in patients receiving itraconazole. Testing of all three isotypes improved the sensitivity; at least two isotypes were detected in 93% of patients before and 89% after treatment. The reactivity of 94 sera from patients with other diseases and healthy individuals was also tested. Cross-reactivity occurred in 33% of the heterologous sera. Most of them were positive only in one isotype, 8.5% were positive for at least two isotypes, and only one serum (1.1%) was positive for the three isotypes. Antibodies produced during S. schenckii infection are diverse, and we demonstrate that an exoantigen ELISA for the detection of combinations of IgA, IgG, and IgM antibodies is a highly sensitive and specific diagnostic assay for sporotrichosis.

scholarly journals Analysis of IgG, IgA, and IgM antibodies against SARS-CoV-2 spike protein S1 in convalescent and vaccinated patients with the Pfizer-BioNTech and CanSinoBio vaccines

2021 ◽  
Author(s):  
Edgar Melgoza-González ◽  
Diana Hinojosa-Trujillo ◽  
Monica Resendiz ◽  
Verónica Mata-Haro ◽  
Sofía Hernández-Valenzuela ◽  
...  
Keyword(s):  
Indirect Elisa ◽  
Natural Infection ◽  
Rapid Development ◽  
Elisa Test ◽  
Antibody Detection ◽  
Diagnostic Tools ◽  
Igg Antibodies ◽  
The World ◽  
The One ◽  
First Time

The SARS-CoV-2 virus was detected for the first time in December 2019 in Wuhan, China. Currently, this virus has spread around the world, and new variants have emerged. This new pandemic virus provoked the rapid development of diagnostic tools, therapies and vaccines to control this new disease called COVID-19. Antibody detection by ELISA has been broadly used to recognize the number of persons infected with this virus or to evaluate the response of vaccinated individuals. As the pandemic spread, new questions arose, such as the prevalence of antibodies after natural infection and the response induced by the different vaccines. In Mexico, as in other countries, mRNA and viral-vectored vaccines have been widely used among the population. In this work, we developed an indirect ELISA test to evaluate S1 antibodies in convalescent and vaccinated individuals. By using this test, we showed that IgG antibodies against the S1 protein of SARS-CoV-2 were detected up to 42 weeks after the onset of the symptoms, in contrast to IgA and IgM, which decreased 14 weeks after the onset of symptoms. The evaluation of the antibody response in individuals vaccinated with Pfizer-BioNTech and CanSinoBio vaccines showed no differences two weeks after vaccination. However, after completing the two doses of Pfizer-BioNTech and the one dose of CanSinoBio, a significantly higher response of IgG antibodies was observed in persons vaccinated with Pfizer-BioNTech than in those vaccinated with CanSinoBio. In conclusion, these results confirm that after natural infection with SARS-CoV-2, it is possible to detect antibodies for up to ten months. Additionally, our results showed that one dose of the CanSinoBio vaccine induces a lower response of IgG antibodies than that induced by the complete scheme of the Pfizer-BioNTech vaccine.

scholarly journals Significantly Low Levels of IgG Antibodies Against Oncogenic Merkel Cell Polyomavirus in Sera From Females Affected by Spontaneous Abortion

2021 ◽  
Vol 12 ◽  
Author(s):  
Chiara Mazziotta ◽  
Giulia Pellielo ◽  
Mauro Tognon ◽  
Fernanda Martini ◽  
John Charles Rotondo
Keyword(s):  
Antibody Response ◽  
Spontaneous Abortion ◽  
Viral Infections ◽  
Merkel Cell Polyomavirus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Merkel Cell ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
The Impact

Merkel cell polyomavirus (MCPyV) is a small DNA tumor virus ubiquitous in humans. MCPyV establishes a clinically asymptomatic lifelong infection in healthy immunocompetent individuals. Viral infections are considered to be risk factors for spontaneous abortion (SA), which is the most common adverse complication of pregnancy. The role of MCPyV in SA remains undetermined. Herein, the impact of MCPyV infection in females affected by SA was investigated. Specifically, an indirect enzyme-linked immunosorbent assay (ELISA) method with two linear synthetic peptides/mimotopes mimicking MCPyV antigens was used to investigate immunoglobulin G (IgG) antibodies against MCPyV in sera from 94 females affected by SA [mean ± standard deviation (SD) age 35 ± (6) years] and from 96 healthy females undergoing voluntary pregnancy interruption [VI, mean (±SD) age 32 ± (7) years]. MCPyV seroprevalence and serological profiles were analyzed. The overall prevalence of serum IgG antibodies against MCPyV was 35.1% (33/94) and 37.5% (36/96) in SA and VI females, respectively (p > 0.05). Notably, serological profile analyses indicated lower optical densities (ODs) in females with SA compared to those undergoing VI (p < 0.05), thus indicating a reduced IgG antibody response in SA females. Circulating IgGs were identified in sera from SA and VI females. Our immunological findings indicate that a relatively reduced fraction of pregnant females carry serum anti-MCPyV IgG antibodies, while SA females presented a more pronounced decrease in IgG antibody response to MCPyV. Although yet to be determined, this immunological decrease might prompt an increase in MCPyV multiplication events in females experiencing abortive events. The role of MCPyV in SA, if present, remains to be determined.

scholarly journals A rapid and highly sensitive biomarker detection platform based on a temperature-responsive liposome-linked immunosorbent assay

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Runkai Hu ◽  
Keitaro Sou ◽  
Shinji Takeoka
Keyword(s):  
Immunosorbent Assay ◽  
Limit Of Detection ◽  
Specific Antigen ◽  
Fluorescence Emission ◽  
Detection Sensitivity ◽  
Sensitive Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Temperature Responsive ◽  
Highly Sensitive ◽  
Highly Sensitive Detection

Abstract The enzyme-linked immunosorbent assay (ELISA) is widely used in various fields to detect specific biomarkers. However, ELISA tests have limited detection sensitivity (≥ 1 pM), which is insufficiently sensitive for the detection of small amounts of biomarkers in the early stages of disease or infection. Herein, a method for the rapid and highly sensitive detection of specific antigens, using temperature-responsive liposomes (TLip) containing a squaraine dye that exhibits fluorescence at the phase transition temperature of the liposomes, was developed. A proof-of-concept study using biotinylated TLip and a streptavidin-immobilized microwell plate showed that the TLip bound to the plate via specific molecular recognition could be distinguished from unbound TLip within 1 min because of the difference in the heating time required for the fluorescence emission of TLip. This system could be used to detect prostate specific antigen (PSA) based on a sandwich immunosorbent assay using detection and capture antibodies, in which the limit of detection was as low as 27.6 ag/mL in a 100-μL PSA solution, 0.97 aM in terms of molar concentration. The present temperature-responsive liposome-linked immunosorbent assay provides an advanced platform for the rapid and highly sensitive detection of biomarkers for use in diagnosis and biological inspections.

scholarly journals Sensitivity and Kinetics of an NS1-Based Zika Virus Enzyme-Linked Immunosorbent Assay in Zika Virus-Infected Travelers from Israel, the Czech Republic, Italy, Belgium, Germany, and Chile

2017 ◽  
Vol 55 (6) ◽  
pp. 1894-1901 ◽  
Author(s):  
Yaniv Lustig ◽  
Hana Zelena ◽  
Giulietta Venturi ◽  
Marjan Van Esbroeck ◽  
Camilla Rothe ◽  
...  
Keyword(s):  
Czech Republic ◽  
Immunosorbent Assay ◽  
Zika Virus ◽  
False Negative ◽  
Cross Reactivity ◽  
Diagnostic Methods ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Kinetics Of

ABSTRACT Serological diagnosis of Zika virus is challenging due to high cross-reactivity of Zika virus with other flavivirus antibodies. Recently, a Zika NS1-based enzyme-linked immunosorbent assay (ELISA) was developed and shown to be highly specific for Zika antibody detection; however, sensitivity was evaluated for only a small number of confirmed Zika-infected patients. In this study, we measured the sensitivity and kinetics of Zika IgM and IgG antibodies using the Zika NS1-based ELISA in 105 samples from 63 returning travelers infected with Zika virus (proven by PCR or neutralization assay) from Israel, Czech Republic, Italy, Belgium, Germany, and Chile. Zika virus IgM was detected from 2 to 42 days post-symptom onset (PSO) with an overall sensitivity of 79% in the first month and 68% until 2 months PSO, while IgG antibodies were detected from 5 days to 3 years PSO with 79% sensitivity. Interestingly, significant differences in IgM sensitivity and IgM detection period were observed between Israeli and European/Chilean Zika-infected travelers, adding to the complexity of Zika infection diagnosis and suggesting that other diagnostic methods should be complemented to reduce false-negative results.

Validation of a chemiluminescent assay for specific SARS-CoV-2 antibody

2020 ◽  
Vol 58 (8) ◽  
pp. 1357-1364 ◽  
Author(s):  
Marie Tré-Hardy ◽  
Alain Wilmet ◽  
Ingrid Beukinga ◽  
Jean-Michel Dogné ◽  
Jonathan Douxfils ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Elisa Test ◽  
Diagnostic Methods ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Elisa Method ◽  
Serological Tests ◽  
Economy Of Scale

AbstractObjectivesFaced with the COVID-19 pandemic and its impact on the availability and quality of both therapeutic and diagnostic methods, the Belgian authorities have decided to launch a procedure for additional evaluation of the performance of serological tests offered for sale on the national territory. This has been proposed with a double aim: (1) an in-depth verification of the analytical and clinical performances presented by the manufacturer and (2) an economy of scale in terms of centralized validation for all the laboratories using the tests subject to evaluation.MethodsA retrospective validation study was conducted including the serum of 125 patients in order to determine the analytical and clinical performances of the LIAISON®SARS-CoV-2 from DiaSorin® detecting anti-SARS-CoV-2 IgG and to compare its clinical performance with the enzyme-linked immunosorbent assay (ELISA) test from Euroimmun®, one of the first commercially available tests allowing the detection of anti-SARS-CoV-2 IgA and IgG.ResultsThe performances of the LIAISON®SARS-CoV-2 satisfied all the acceptance criteria and provided “real world” analytical and clinical performances very close to the ones reported by the manufacturer in its insert kit. Comparison between the LIAISON®SARS-CoV-2 and the ELISA method did not reveal any difference between the two techniques in terms of sensitivities and specificities regarding the determination of the IgG.ConclusionsThis study reports the validation of the LIAISON®SARS-CoV-2 allowing to detect IgG antibodies specifically directed against SARS-CoV-2. The analytical and clinical performances are excellent, and the automation of the test offers important rates, ideal for absorbing an extension of testing.

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