scholarly journals Performance of Abbott Architect, Ortho Vitros, and Euroimmun Assays in Detecting Prior SARS-CoV-2 Infection

Author(s):  
Shiwani Mahajan ◽  
Carrie A Redlich ◽  
Adam V Wisnewski ◽  
Louis E Fazen ◽  
Lokinendi V Rao ◽  
...  

Background: Several serological assays have been developed to detect anti-SARS-CoV-2 IgG antibodies, but evidence about their comparative performance is limited. We sought to assess the sensitivity of four anti-SARS-CoV-2 IgG enzyme-linked immunosorbent assays (ELISA) in individuals with evidence of prior SARS-CoV-2 infection. Methods: We obtained sera from 36 individuals with PCR-confirmed SARS-CoV-2 infection between March and May 2020. We evaluated samples collected at around 21 days (±14 days) after their initial PCR test using 3 commercially available ELISA assays, two anti-spike (Ortho-Clinical Diagnostics Vitros, and Euroimmun) and one anti-nucleocapsid (Abbott Architect), and a Yale-developed anti-spike ELISA test. We determined the sensitivity of the tests and compared their results. The Euroimmun and Yale ELISA had an equivocal and indeterminate category, which were considered as both negative and positive. Results: Among the 36 individuals with SARS-CoV-2 infection, mean age was 43 (±13) years and 19 (53%) were female. The sensitivities of the tests were not significantly different (Abbott Architect, Ortho Vitros, Euroimmmun, and Yale assays: 86% (95% confidence interval [CI], 71-95), 94% (95% CI, 81-99), 86% (95% CI, 71-95), and 94% (95% CI, 81-99), respectively; p-value=0.464). The sensitivities of the Euroimmun and Yale ELISA tests increased when the equivocal/indeterminate results were considered positive (97% [95% CI, 85-100] and 100% [95% CI, 90-100], respectively), but were not significantly different from other tests (p=0.082). The cross-correlation coefficient ranged from 0.85-0.98 between three anti-spike protein assays (Ortho Vitros, Euroimmun, Yale) and was 0.58-0.71 between the three anti-spike protein assays and the anti-nucleocapsid assay (Abbott). Conclusion: The sensitivities of four anti-SARS-CoV-2 protein assays did not significantly differ, although the sample size was small. Sensitivity also depended on the interpretation of equivocal and indeterminate results. The strongest correlations were present for the three anti-spike proteins assays. These findings suggest that individual test characteristics and the correlation between different tests should be considered when comparing or aggregating data across different populations studies for serologic surveillance of past SARS-CoV-2 infection.

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0255208
Author(s):  
Ashutosh Wadhwa ◽  
Sherry Yin ◽  
Brandi Freeman ◽  
Rebecca B. Hershow ◽  
Marie Killerby ◽  
...  

Serologic assays developed for SARS-CoV-2 detect different antibody subtypes and are based on different target antigens. Comparison of the performance of a SARS-CoV-2 Spike-Protein ELISA and the nucleocapsid-based Abbott ArchitectTM SARS-CoV-2 IgG assay indicated that the assays had high concordance, with rare paired discordant tests results.


2021 ◽  
Vol 30 (1) ◽  
pp. 71-77
Author(s):  
Sahar M. Khairat ◽  
Nancy ELGuindy ◽  
Amany E. Sheta ◽  
Usama A. Bahaa Eldin ◽  
Yasmin Adel El-Mahdy ◽  
...  

Background: COVID-19 is a pandemic of serious global threat that forced test developers to flood the market with various diagnostic assays that have been independently validated. Objectives: This study aims at assessing the performance of four SARS-CoV-2 chemiluminescence immunoassays. Methodology: The present study included sera from 96 Polymerase Chain Reaction (PCR)–confirmed COVID-19 cases collected at 2 time periods (5-9 days and 9-14 days post symptom onset) during patient follow-up, and 30 control sera from COVID-19 PCR–negative individuals. All sera were tested for SARS-CoV-2 antibodies using four high-throughput commercially available chemiluminescence immunoassays: YHLO Biotech Co, Ltd China (IgM and IgG); Abbott, Abbott USA (IgG); Roche, Roche US (total: IgM, IgG, and IgA), and Ortho, Ortho Clinical Diagnostics, USA (total and individual IgG). Results: For the detection of total antibodies (IgM, IgG, and IgA), the highest sensitivities were for Ortho followed by Roche assays (91.6% and 84.3% in 5-9 days period, respectively) raised to 96.8% and 92.7% in 9-14 days respectively with significant difference P-value <0.00001. Ortho, Roche, and YHLO iFlash (IgM) assays had specificities of 100%, 100%, and 90.3% respectively. Roche (Total) and Ortho (Total) assays showed perfect categorical agreement (94.4% in 5-9 days, and 96.4% in 9-14 days). As for the detection of individual IgG antibodies, the Abbott assay had the highest sensitivity (91.6% in 5-9 days, and 93.7% in 9-14 days), followed by Ortho and YHLO iFlash assays (84.3%, and 83.3% in 5-9 days respectively) that increased to 89.5% and 88.5% in 9-14 days respectively. Ortho assay was the best in specificity (100%), followed by Abbott (98.8%) and YHLO iFlash (96.3%). YHLO iflash (IgG) and Ortho (IgG) showed perfect agreement (96.8%) in the 2 time frames. Conclusion: Ortho assay showed the best performance in detecting total antibodies with perfect match to Roche assay, while Abott assay was the best performing in detecting individual IgG with perfect match to Ortho assay rendering them to be efficient diagnostic tools


Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1075
Author(s):  
Salvatore Ledda ◽  
Cinzia Santucciu ◽  
Valentina Chisu ◽  
Giovanna Masala

Q fever is a zoonosis caused by Coxiella burnetii, a Gram-negative pathogen with a complex life cycle and a high impact on public and animal health all over the world. The symptoms are indistinguishable from those belonging to other diseases, and the disease could be symptomless. For these reasons, reliable laboratory tests are essential for an accurate diagnosis. The aim of this study was to validate a novel enzyme-linked immunosorbent assay (ELISA) test, named the Chorus Q Fever Phase II IgG and IgM Kit (DIESSE, Diagnostica Senese S.p.A), which is performed by an instrument named Chorus, a new device in medical diagnostics. This diagnostic test is employed for the detection of antibodies against C. burnetii Phase II antigens in acute disease. Our validation protocol was performed according to the Italian Accreditation Body (ACCREDIA) (Regulation UNI CEI EN ISO/IEC 17025:2018 and 17043:2010), OIE (World Organization for Animal Health), and Statement for Reporting Studies of Diagnostic Accuracy (STARD). Operator performance was evaluated along with the analytical specificity and sensitivity (ASp and ASe) and diagnostic accuracy of the kit, with parameters such as diagnostic specificity and sensitivity (DSp and DSe) and positive and negative predictive values (PPV and NPV), in addition to the repeatability. According to the evaluated parameters, the diagnostic ELISA test was shown to be suitable for validation and commercialization as a screening method in human sera and a valid support for clinical diagnostics.


Author(s):  
Peter A. Kavsak ◽  
Tara Edge ◽  
Chantele Roy ◽  
Paul Malinowski ◽  
Karen Bamford ◽  
...  

AbstractObjectivesTo analytically evaluate Ortho Clinical Diagnostics VITROS high-sensitivity cardiac troponin I (hs-cTnI) assay in specific matrices with comparison to other hs-cTn assays.MethodsThe limit of detection (LoD), imprecision, interference and stability testing for both serum and lithium heparin (Li-Hep) plasma for the VITROS hs-cTnI assay was determined. We performed Passing-Bablok regression analyses between sample types for the VITROS hs-cTnI assay and compared them to the Abbott ARCHITECT, Beckman Access and the Siemens ADVIA Centaur hs-cTnI assays. We also performed Receiver-operating characteristic curve analyses with the area under the curve (AUC) determined in an emergency department (ED)-study population (n=131) for myocardial infarction (MI).ResultsThe VITROS hs-cTnI LoD was 0.73 ng/L (serum) and 1.4 ng/L (Li-Hep). Stability up to five freeze-thaws was observed for the Ortho hs-cTnI assay, with the analyte stability at room temperature in serum superior to Li-Hep with gross hemolysis also affecting Li-Hep plasma hs-cTnI results. Comparison of Li-Hep to serum concentrations (n=202), yielded proportionally lower concentrations in plasma with the VITROS hs-cTnI assay (slope=0.85; 95% confidence interval [CI]:0.83–0.88). In serum, the VITROS hs-cTnI concentrations were proportionally lower compared to other hs-cTnI assays, with similar slopes observed between assays in samples frozen <−70 °C for 17 years (ED-study) or in 2020. In the ED-study, the VITROS hs-cTnI assay had an AUC of 0.974 (95%CI:0.929–0.994) for MI, similar to the AUCs of other hs-cTn assays.ConclusionsLack of standardization of hs-cTnI assays across manufacturers is evident. The VITROS hs-cTnI assay yields lower concentrations compared to other hs-cTnI assays. Important differences exist between Li-Hep plasma and serum, with evidence of stability and excellent clinical performance comparable to other hs-cTn assays.


2021 ◽  
Vol 22 (5) ◽  
pp. 2630
Author(s):  
Chunguang Liang ◽  
Elena Bencurova ◽  
Eric Psota ◽  
Priya Neurgaonkar ◽  
Martina Prelog ◽  
...  

We observed substantial differences in predicted Major Histocompatibility Complex II (MHCII) epitope presentation of SARS-CoV-2 proteins for different populations but only minor differences in predicted MHCI epitope presentation. A comparison of this predicted epitope MHC-coverage revealed for the early phase of infection spread (till day 15 after reaching 128 observed infection cases) highly significant negative correlations with the case fatality rate. Specifically, this was observed in different populations for MHC class II presentation of the viral spike protein (p-value: 0.0733 for linear regression), the envelope protein (p-value: 0.023), and the membrane protein (p-value: 0.00053), indicating that the high case fatality rates of COVID-19 observed in some countries seem to be related with poor MHC class II presentation and hence weak adaptive immune response against these viral envelope proteins. Our results highlight the general importance of the SARS-CoV-2 structural proteins in immunological control in early infection spread looking at a global census in various countries and taking case fatality rate into account. Other factors such as health system and control measures become more important after the early spread. Our study should encourage further studies on MHCII alleles as potential risk factors in COVID-19 including assessment of local populations and specific allele distributions.


Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 1041
Author(s):  
Mohammad Tarek ◽  
Hana Abdelzaher ◽  
Firas Kobeissy ◽  
Hassan A. N. El-Fawal ◽  
Mohammed M. Salama ◽  
...  

The virus responsible for the COVID-19 global health crisis, SARS-CoV-2, has been shown to utilize the ACE2 protein as an entry point to its target cells. The virus has been shown to rely on the actions of TMPRSS2 (a serine protease), as well as FURIN (a peptidase), for the critical priming of its spike protein. It has been postulated that variations in the sequence and expression of SARS-CoV-2’s receptor (ACE2) and the two priming proteases (TMPRSS2 and FURIN) may be critical in contributing to SARS-CoV-2 infectivity. This study aims to examine the different expression levels of FURIN in various tissues and age ranges in light of ACE2 and TMPRSS2 expression levels using the LungMAP database. Furthermore, we retrieved expression quantitative trait loci (eQTLs) of the three genes and their annotation. We analyzed the frequency of the retrieved variants in data from various populations and compared it to the Egyptian population. We highlight FURIN’s potential interplay with the immune response to SARS-CoV-2 and showcase a myriad of variants of the three genes that are differentially expressed across populations. Our findings provide insights into potential genetic factors that impact SARS-CoV-2 infectivity in different populations and shed light on the varying expression patterns of FURIN.


Author(s):  
Elizabeth A. Simpson ◽  
David A. Skoglund ◽  
Sarah E. Stone ◽  
Ashley K. Sherman

Objective This study aimed to determine the factors associated with positive infant drug screen and create a shortened screen and a prediction model. Study Design This is a retrospective cohort study of all infants who were tested for drugs of abuse from May 2012 through May 2014. The primary outcome was positive infant urine or meconium drug test. Multivariable logistic regression was used to identify independent risk factors. A combined screen was created, and test characteristics were analyzed. Results Among the 3,861 live births, a total of 804 infants underwent drug tests. Variables associated with having a positive infant test were (1) positive maternal urine test, (2) substance use during pregnancy, (3) ≤ one prenatal visit, and (4) remote substance abuse; each p-value was less than 0.0001. A model with an indicator for having at least one of these four predictors had a sensitivity of 94% and a specificity of 69%. Application of this screen to our population would have decreased drug testing by 57%. No infants had a positive urine drug test when their mother's urine drug test was negative. Conclusion This simplified screen can guide clinical decision making for determining which infants should undergo drug testing. Infant urine drug tests may not be needed when a maternal drug test result is negative. Key Points


1998 ◽  
Vol 13 (6) ◽  
pp. 377-387
Author(s):  
P Carayon ◽  
P Douet ◽  
A Gruson ◽  
J.P. Klein ◽  
P.J. Lejeune ◽  
...  

2021 ◽  
Author(s):  
Farah M. Shurrab ◽  
Duaa W. Al-Sadeq ◽  
Fathima Amanullah ◽  
Salma N. Younes ◽  
Hadeel Al-Jighefee ◽  
...  

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.


2021 ◽  
Author(s):  
Pritha Ghosh ◽  
Rohit Suratekar ◽  
Michiel J.M. Niesen ◽  
Praveen Anand ◽  
Gregory Donadio ◽  
...  

The highly contagious Delta variant of SARS-CoV-2 has emerged as the new dominant global strain, and reports of reduced effectiveness of COVID-19 vaccines against the Delta variant are highly concerning. While there has been extensive focus on understanding the amino acid mutations in the Delta variant's Spike protein, the mutational landscape of the rest of the SARS-CoV-2 proteome (25 proteins) remains poorly understood. To this end, we performed a systematic analysis of mutations in all the SARS-CoV-2 proteins from nearly 2 million SARS-CoV-2 genomes from 176 countries/territories. Six highly-prevalent missense mutations in the viral life cycle-associated Membrane (I82T), Nucleocapsid (R203M, D377Y), NS3 (S26L), and NS7a (V82A, T120I) proteins are almost exclusive to the Delta variant compared to other variants of concern (mean prevalence across genomes: Delta = 99.74%, Alpha = 0.06%, Beta = 0.09%, Gamma = 0.22%). Furthermore, we find that the Delta variant harbors a more diverse repertoire of mutations across countries compared to the previously dominant Alpha variant (cosine similarity: meanAlpha = 0.94, S.D.Alpha = 0.05; meanDelta = 0.86, S.D.Delta = 0.1; Cohen's dAlpha-Delta = 1.17, p-value < 0.001). Overall, our study underscores the high diversity of the Delta variant between countries and identifies a list of targetable amino acid mutations in the Delta variant's proteome for probing the mechanistic basis of pathogenic features such as high viral loads, high transmissibility, and reduced susceptibility against neutralization by vaccines.


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