scholarly journals Validation of Roche immunoassay for severe acute respiratory coronavirus 2 in South Africa

2021 ◽  
Vol 36 (1) ◽  
Author(s):  
Jurette S. Grove ◽  
Elizabeth S. Mayne ◽  
Wendy A. Burgers ◽  
Jonathan Blackburn ◽  
Sarika Jugwanth ◽  
...  
Keyword(s):  
High Specificity ◽  
Lower Sensitivity ◽  
Rt Pcr ◽  
Serum Samples ◽  
Time Points ◽  
Human Research Ethics ◽  
Chemiluminescent Immunoassay ◽  
Academic Laboratory ◽  
Negative Controls ◽  
Respiratory Coronavirus

Background: Serology testing is an important ancillary diagnostic to the reverse transcriptase polymerase chain reaction (RT-PCR) test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We aimed to evaluate the performance of the Roche Elecsys™ chemiluminescent immunoassay (Rotkreuz, Switzerland), that detects antibodies against the SARS-CoV-2 nucleocapsid antigen, at an academic laboratory in South Africa.Methods: Serum samples were collected from 312 donors with confirmed positive SARS-CoV-2 RT-PCR tests, with approval from a large university’s human research ethics committee. Negative controls included samples stored prior to December 2019 and from patients who tested negative for SARS-CoV-2 on RT-PCR and were confirmed negative using multiple serology methods (n = 124). Samples were stored at –80 °C and analysed on a Roche cobas™ 602 autoanalyser.Results: Compared with RT-PCR, our evaluation revealed a specificity of 100% and overall sensitivity of 65.1%. The sensitivity in individuals 14 days’ post-diagnosis was 72.6%, with the highest sensitivity 31–50 days’ post-diagnosis at 88.6%. Results were also compared with in-house serology tests that showed high agreement in majority of categories.Conclusions: The sensitivity at all-time points post-diagnosis was lower than reported in other studies, but sensitivity in appropriate cohorts approached 90% with a high specificity. The lower sensitivity at earlier time points or in individuals without symptomatology may indicate failure to produce antibodies, which was further supported by the comparison against in-house serology tests.

scholarly journals Long-Term Longitudinal Evaluation of Six Commercial Immunoassays for the Detection of IgM and IgG Antibodies against SARS CoV-2

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1244
Author(s):  
Iulia Nedelcu ◽  
Raluca Jipa ◽  
Roxana Vasilescu ◽  
Cristian Băicuș ◽  
Costin-Ioan Popescu ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Sample Selection ◽  
Early Time ◽  
Humoral Response ◽  
High Specificity ◽  
Data Interpretation ◽  
Serum Samples ◽  
Chemiluminescent Immunoassay ◽  
Chemiluminescent Microparticle Immunoassay ◽  
Antibody Levels

The number of serological assays for SARS-CoV-2 has skyrocketed in the past year. Concerns have been raised regarding their performance characteristics, depending on the disease severity and the time of the analysis post-symptom onset (PSO). Thus, independent validations using an unbiased sample selection are required for meaningful serology data interpretation. We aimed to assess the clinical performance of six commercially available assays, the seroconversion, and the dynamics of the humoral response to SARS-CoV-2 infection. The study included 528 serum samples from 156 patients with follow-up visits up to six months PSO and 161 serum samples from healthy people. The IgG/total antibodies positive percentage increased and remained above 95% after six months when chemiluminescent immunoassay (CLIA) IgG antiS1/S2 and electro-chemiluminescent assay (ECLIA) total antiNP were used. At early time points PSO, chemiluminescent microparticle immunoassay (CMIA) IgM antiS achieved the best sensitivity. IgM and IgG appear simultaneously in most circumstances, and when performed in parallel the sensitivity increases. The severe and the moderate clinical forms were significantly associated with higher seropositivity percentage and antibody levels. High specificity was found in all evaluated assays, but the sensitivity was variable depending on the time PSO, severity of disease, detection method and targeted antigen.

scholarly journals Performance of Commercially Available Rapid Serological Assays for the Detection of SARS-CoV-2 Antibodies

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1067
Author(s):  
Anwar M. Hashem ◽  
Rowa Y. Alhabbab ◽  
Abdullah Algaissi ◽  
Mohamed A. Alfaleh ◽  
Sharif Hala ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Significant Variation ◽  
High Specificity ◽  
Lateral Flow ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Standard Methods ◽  
Specific Antibodies ◽  
Time Points

The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continues to spread globally. Although several rapid commercial serological assays have been developed, little is known about their performance and accuracy in detecting SARS-CoV-2-specific antibodies in COVID-19 patient samples. Here, we have evaluated the performance of seven commercially available rapid lateral flow immunoassays (LFIA) obtained from different manufacturers, and compared them to in-house developed and validated ELISA assays for the detection of SARS-CoV-2-specific IgM and IgG antibodies in RT-PCR-confirmed COVID-19 patients. While all evaluated LFIA assays showed high specificity, our data showed a significant variation in sensitivity of these assays, which ranged from 0% to 54% for samples collected early during infection (3–7 days post symptoms onset) and from 54% to 88% for samples collected at later time points during infection (8–27 days post symptoms onset). Therefore, we recommend prior evaluation and validation of these assays before being routinely used to detect IgM and IgG in COVID-19 patients. Moreover, our findings suggest the use of LFIA assays in combination with other standard methods, and not as an alternative.

scholarly journals Clinical Evaluation of a COVID-19 Antibody Lateral Flow Assay using Point of Care Samples

2020 ◽  
Author(s):  
Won Lee ◽  
Steven Straube ◽  
Ryan Sincic ◽  
Jeanne A. Noble ◽  
Juan Carlos Montoy ◽  
...  
Keyword(s):  
Predictive Value ◽  
Point Of Care ◽  
Acute Infection ◽  
High Specificity ◽  
Lateral Flow ◽  
Lateral Flow Immunoassay ◽  
Onset Date ◽  
Rt Pcr ◽  
Serum Samples ◽  
Antibody Positivity

ABSTRACTIntroductionThe ongoing SARS-CoV-2 pandemic has spurred the development of numerous point of care (PoC) immunoassays. Assessments of performance of available kits are necessary to determine their clinical utility. Previous studies have mostly performed these assessments in a laboratory setting, which raises concerns of translating findings for PoC use. The aim of this study was to assess the performance of a lateral flow immunoassay for the detection of SARS-CoV-2 antibodies using samples collected at PoC.MethodOne lateral flow immunoassay (Humasis® COVID-19 IgG/IgM) was tested. In total, 50 PCR RT-PCR positive and 52 RT-PCR negative samples were collected at PoC. Fifty serum specimens from Dec 2018 to Feb 2019 were used as controls for specificity. Serum samples collected between Dec 2019 to Feb 2020 were used as additional comparators. Clinical data including symptom onset date was collected from patient history and the medical record.ResultsThe overall sensitivity for the kit was 74% (95% CI: 59.7% -85.4%). The sensitivity for IgM and IgG detection >14 days after date of onset was 88% (95% CI: 68.8% -97.5%) and 84% (95% CI: 63.9% – 95.5%), with a negative predictive value (NPV) of 94% for IgM (95% CI: 83.5% - 98.8%) and 93% for IgG (95% CI: 81.8% - 97.9%). The overall specificity was 94% (95% CI: 83.5% - 98.8%). The Immunoglobulin specific specificity was 94% for IgM (95% CI: 83.5% - 98.8%) and 98% for IgG (95% CI: 89.4% - 100.0%), with a positive predictive value (PPV) of 88% for IgM (95% CI: 68.8% - 97.5%) and 95% for IgG (95% CI: 77.2% - 99.9%) respectively for samples collected from patients >14 days after date of onset. Specimen collected during early phase of COVID-19 pandemic (Dec 2019 to Feb 2020) showed 11.8% antibody positivity, and 11.3% of PCR-negative patients demonstrated antibody positivity.DiscussionHumasis® COVID-19 IgG/IgM LFA demonstrates greater than 90% PPV and NPV for samples collected 14 days after the onset of symptoms using samples collected at PoC. While not practical for the diagnosis of acute infection, the use of the lateral flow assays with high specificity may have utility for determining seroprevalence or seroconversion in longitudinal studies.

scholarly journals Development of the kit for diagnostics of COVID-19 by real time RT-PCR

2020 ◽  
Author(s):  
AK Shuryaeva ◽  
TV Malova ◽  
EE Davydova ◽  
YuA Savochkina ◽  
EV Bogoslovskaya ◽  
...  
Keyword(s):  
Real Time ◽  
Diagnostic System ◽  
High Specificity ◽  
Test System ◽  
Analytical Sensitivity ◽  
Rt Pcr ◽  
The Russian Federation ◽  
Diagnostic Sensitivity And Specificity ◽  
Respiratory Coronavirus ◽  
The City

Late in December 2019, an outbreak of an unknown coronavirus, later identified as SARS-CoV- 2, emerged in the city of Wuhan, China. It causes a dangerous respiratory coronavirus disease in humans - COVID-19. Objective. To detect cases of the disease and prevent its spread across the Russian Federation it is necessary to create an effective diagnostic test system. Material and methods. Based on the analysis of the alignment of the SARS-CoV-2 nucleotide sequences, primers and a probe for RT-PCR were selected, and the analysis conditions were optimized. Results. The diagnostic system was developed and registered in the shortest possible time in real-time RT-PCR format for detecting SARS-CoV-2 coronavirus RNA in smears from the nasopharynx and oropharynx, sputum and feces. The high specificity of the system was verified on a representative set of viruses and microorganisms, the analytical sensitivity was 1x103 copies / ml in smears from the mucous membrane of the nasopharynx and oropharynx and sputum, 5x104 copies / ml in fecal samples. Diagnostic sensitivity and specificity established during clinical trials on samples from patients with confirmed COVID-19 infection, from patients with a different etiology of a disease and clinically healthy people were to 100% (range 94.2-100% with a confidence level of 95%).

scholarly journals EXPRESS: Evaluation of usability of various rapid antibody tests in diagnostic application for COVID-19

2020 ◽  
pp. 000456322098482
Author(s):  
Yoshifumi Uwamino ◽  
Masatoshi Wakui ◽  
Wataru Aoki ◽  
Toshinobu Kurafuji ◽  
Emmy Yanagita ◽  
...  
Keyword(s):  
Antibody Test ◽  
Antibody Detection ◽  
Rt Pcr ◽  
Serum Samples ◽  
Quantitative Test ◽  
Pcr Diagnosis ◽  
Rapid Tests ◽  
Chemiluminescent Immunoassay ◽  
Antibody Tests ◽  
Rapid Antibody

Background: The usability of laboratory tests related to SARS-CoV-2 is critically important for the world undergoing the COVID-19 pandemic. The present study aimed to assess diagnostic usability of rapid tests for detection of antibody against SARS-CoV-2 through comparison of their results with results of RT-PCR test for detection of SARS-CoV-2 genomic RNA and with results of a quantitative test for antibody detection. Methods: Serum samples were collected from eighteen patients undergoing RT-PCR testing for SARS-CoV-2. Twelve patients were RT-PCR positive while six were negative. A quantitative test based on chemiluminescent immunoassay and three rapid tests based on immunochromatography were performed to detect anti-SARS-CoV-2 IgG and IgM. Results: All the antibody tests exhibited poor sensitivity at the timing of initial RT-PCR diagnosis. IgG responses occurring prior to or simultaneously with IgM responses were observed through not only the quantitative test but also the three rapid tests. Based on concordance with the quantitative test results, the large variance among the three rapid tests was revealed. Conclusions: All antibody tests were unsatisfactory to replace RT-PCR for early diagnosis of COVID-19. Rapid antibody tests as well as a quantitative antibody test were useful in assessment of immune responses in COVID-19. The obvious variance among the three rapid tests suggested limited accuracy and difficult standardization. Diagnostic usability of rapid antibody tests for COVID-19 should be investigated rigorously.

531: Quantitative Real-Time RT-PCR for AMACR Distinguishes Prostate Cancer with High Specificity From Benign Lesions

2005 ◽  
Vol 173 (4S) ◽  
pp. 145-145 ◽  
Author(s):  
Martin Schostak ◽  
Hans Krause ◽  
Jens Köllermann ◽  
Mark Schrader ◽  
Bernd Straub ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Real Time ◽  
High Specificity ◽  
Rt Pcr ◽  
Benign Lesions

scholarly journals Investigations, actions and learning from an outbreak of SARS-CoV-2 infection among healthcare workers in the United Kingdom

2020 ◽  
pp. 175717742097679
Author(s):  
Kordo Saeed ◽  
Emanuela Pelosi ◽  
Nitin Mahobia ◽  
Nicola White ◽  
Christopher Labdon ◽  
...  
Keyword(s):  
Real Time ◽  
Healthcare Workers ◽  
Healthcare Facility ◽  
Rt Pcr ◽  
Serum Samples ◽  
The United Kingdom ◽  
Key Issues ◽  
Current Infection ◽  
Polymerase Chain ◽  
A Current

Background: We report an outbreak of SARS coronavirus-2 (SARS-CoV-2) infection among healthcare workers (HCW) in an NHS elective healthcare facility. Methodology: A narrative chronological account of events after declaring an outbreak of SARS-CoV-2 among HCWs. As part of the investigations, HCWs were offered testing during the outbreak. These were: (1) screening by real-time reverse transcriptase polymerase chain reaction (RT- PCR) to detect a current infection; and (2) serum samples to determine seroprevalence. Results: Over 180 HCWs were tested by real-time RT-PCR for SARS-CoV-2 infection. The rate of infection was 15.2% (23.7% for clinical or directly patient-facing HCWs vs. 4.8% in non-clinical non-patient-facing HCWs). Of the infected HCWs, 57% were asymptomatic. Seroprevalence (SARS-CoV-2 IgG) among HCWs was 13%. It was challenging to establish an exact source for the outbreak. The importance of education, training, social distancing and infection prevention practices were emphasised. Additionally, avoidance of unnecessary transfer of patients and minimising cross-site working for staff and early escalation were highlighted. Establishing mass and regular screening for HCWs are also crucial to enabling the best care for patients while maintaining the wellbeing of staff. Conclusion: To our knowledge, this is the first UK outbreak report among HCWs and we hope to have highlighted some key issues and learnings that can be considered by other NHS staff and HCWs globally when dealing with such a task in future.

scholarly journals Implementing SARS-CoV-2 Rapid Antigen Testing in the Emergency Ward of a Swiss University Hospital: The INCREASE Study

2021 ◽  
Vol 9 (4) ◽  
pp. 798
Author(s):  
Giorgia Caruana ◽  
Antony Croxatto ◽  
Eleftheria Kampouri ◽  
Antonios Kritikos ◽  
Onya Opota ◽  
...  
Keyword(s):  
Immunoglobulin A ◽  
University Hospital ◽  
Lower Sensitivity ◽  
Clinical Settings ◽  
Rt Pcr ◽  
Emergency Ward ◽  
Viral Loads ◽  
Asymptomatic Patients ◽  
Asymptomatic Subjects ◽  
Antigen Testing

Following the Swiss Federal Office of Public Health (FOPH) authorization of the rapid antigen test (RAT), we implemented the use of the RAT in the emergency ward of our university hospital for patients’ cohorting. RAT triaging in association with RT-PCR allowed us to promptly isolate positive patients and save resources. Among 532 patients, overall sensitivities were 48.3% for Exdia and 41.2% for Standard Q®, PanbioTM and BD Veritor™. All RATs exhibited specificity above 99%. Sensitivity increased to 74.6%, 66.2%, 66.2% and 64.8% for Exdia, Standard Q®, PanbioTM and BD Veritor™, respectively, for viral loads above 105 copies/mL, to 100%, 97.8%, 96.6% and 95.6% for viral loads above 106 copies/mL and 100% for viral loads above 107 copies/mL. Sensitivity was significantly higher for patients with symptoms onset within four days (74.3%, 69.2%, 69.2% and 64%, respectively) versus patients with the evolution of symptoms longer than four days (36.8%, 21.1%, 21.1% and 23.7%, respectively). Among COVID-19 asymptomatic patients, sensitivity was 33%. All Immunoglobulin-A-positive patients resulted negative for RAT. The RAT might represent a useful resource in selected clinical settings as a complementary tool in RT-PCR for rapid patient triaging, but the lower sensitivity, especially in late presenters and COVID-19 asymptomatic subjects, must be taken into account.

scholarly journals SARS-CoV-2 specific antibody and neutralization assays reveal the wide range of the humoral immune response to virus

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mikail Dogan ◽  
Lina Kozhaya ◽  
Lindsey Placek ◽  
Courtney Gunter ◽  
Mesut Yigit ◽  
...  
Keyword(s):  
Specific Antibody ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
High Specificity ◽  
Spike Protein ◽  
Humoral Immune ◽  
Specificity And Sensitivity ◽  
Wide Range ◽  
Specific Igg ◽  
Negative Controls

AbstractDevelopment of antibody protection during SARS-CoV-2 infection is a pressing question for public health and for vaccine development. We developed highly sensitive SARS-CoV-2-specific antibody and neutralization assays. SARS-CoV-2 Spike protein or Nucleocapsid protein specific IgG antibodies at titers more than 1:100,000 were detectable in all PCR+ subjects (n = 115) and were absent in the negative controls. Other isotype antibodies (IgA, IgG1-4) were also detected. SARS-CoV-2 neutralization was determined in COVID-19 and convalescent plasma at up to 10,000-fold dilution, using Spike protein pseudotyped lentiviruses, which were also blocked by neutralizing antibodies (NAbs). Hospitalized patients had up to 3000-fold higher antibody and neutralization titers compared to outpatients or convalescent plasma donors. Interestingly, some COVID-19 patients also possessed NAbs against SARS-CoV Spike protein pseudovirus. Together these results demonstrate the high specificity and sensitivity of our assays, which may impact understanding the quality or duration of the antibody response during COVID-19 and in determining the effectiveness of potential vaccines.

scholarly journals Delayed neutralizing antibody response in the acute phase correlates with severe progression of COVID-19

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hitoshi Kawasuji ◽  
Yoshitomo Morinaga ◽  
Hideki Tani ◽  
Miyuki Kimura ◽  
Hiroshi Yamada ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Neutralization Test ◽  
Neutralizing Antibody ◽  
Pseudotyped Virus ◽  
Serum Samples ◽  
Neutralization Activity ◽  
Neutralizing Activity ◽  
Time Points ◽  
Moderate Disease ◽  
Activity Dynamics

AbstractAdaptive immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) dynamics remain largely unknown. The neutralizing antibody (NAb) levels in patients with coronavirus disease 2019 (COVID-19) are helpful for understanding the pathology. Using SARS-CoV-2 pseudotyped virus, serum sample neutralization values in symptomatic COVID-19 patients were measured using the chemiluminescence reduction neutralization test (CRNT). At least two sequential serum samples collected during hospitalization were analyzed to assess NAbs neutralizing activity dynamics at different time points. Of the 11 patients, four (36.4%), six (54.5%), and one (9.1%) had moderate, severe, and critical disease, respectively. Fifty percent neutralization (N50%-CRNT) was observed upon admission in 90.9% (10/11); all patients acquired neutralizing activity 2–12 days after onset. In patients with moderate disease, neutralization was observed at earliest within two days after symptom onset. In patients with severe-to-critical disease, neutralization activity increased, plateauing 9–16 days after onset. Neutralization activity on admission was significantly higher in patients with moderate disease than in patients with severe-to-critical disease (relative % of infectivity, 6.4% vs. 41.1%; P = .011). Neutralization activity on admission inversely correlated with disease severity. The rapid NAb response may play a crucial role in preventing the progression of COVID-19.

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