scholarly journals Comparison of sixteen serological SARS-CoV-2 immunoassays in sixteen clinical laboratories

2020 ◽  
Author(s):  
Lene Holm Harritshoej ◽  
Mikkel Gybel-Brask ◽  
Shoaib Afzal ◽  
Pia R. Kamstrup ◽  
Charlotte Svaerke Joergensen ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Blood Donors ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Nucleic Acid Amplification ◽  
Limited Data ◽  
Serum Samples ◽  
Diagnostic Use ◽  
Ig G ◽  
Abbott Architect

Serological SARS-CoV-2 assays are needed to support clinical diagnosis and epidemiological investigations. Recently, assays for the large-volume detection of total antibodies (Ab) and immunoglobulin (Ig) G and M against SARS-CoV-2 antigens have been developed, but there are limited data on the diagnostic accuracy of these assays. This study was organized as a Danish national collaboration and included fifteen commercial and one in-house anti-SARS-CoV-2 assays in sixteen laboratories. Sensitivity was evaluated using 150 serum samples from individuals diagnosed with asymptomatic, mild or moderate nonhospitalized (n=129) or hospitalized (n=31) COVID-19, confirmed by nucleic acid amplification tests, collected 13-73 days from symptom onset. Specificity and cross-reactivity were evaluated in samples collected prior to the SARS-CoV-2 epidemic from > 586 blood donors and patients with autoimmune diseases or CMV or EBV infections. Predefined specificity criteria of ≥99% were met by all total-Ab and IgG assays except one (Diasorin/LiaisonXL-IgG 97.2%). The sensitivities in descending order were: Wantai/ELISA total-Ab (96.7%), CUH/NOVO in-house ELISA total-Ab (96.0%), Ortho/Vitros total-Ab (95.3%), YHLO/iFlash-IgG (94.0%), Ortho/Vitros-IgG (93.3%), Siemens/Atellica total-Ab (93.2%), Roche-Elecsys total-Ab (92.7%), Abbott-Architect-IgG (90.0%), Abbott/Alinity-IgG (median 88.0%), Diasorin/LiaisonXL-IgG (84.6%), Siemens/Vista total-Ab (81.0%), Euroimmun/ELISA-IgG (78.0%), and Snibe/Maglumi-IgG (median 78.0%). The IgM results were variable, but one assay (Wantai/ELISA-IgM) had both high sensitivity (82.7%) and specificity (99%). The rate of seropositivity increased with time from symptom onset and symptom severity. In conclusion, predefined sensitivity and specificity acceptance criteria of 90%/99%, respectively, for diagnostic use were met in five of six total-Ab and three of seven IgG assays.

scholarly journals Comparison of sixteen serological SARS-CoV-2 immunoassays in sixteen clinical laboratories

2021 ◽  
Author(s):  
Lene H. Harritshøj ◽  
Mikkel Gybel-Brask ◽  
Shoaib Afzal ◽  
Pia R. Kamstrup ◽  
Charlotte S. Jørgensen ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Large Scale ◽  
Viral Infections ◽  
Cross Reactivity ◽  
Nucleic Acid Amplification ◽  
Virus Infections ◽  
Limited Data ◽  
Barr Virus ◽  
Epstein Barr ◽  
Scale Detection

Serological SARS-CoV-2 assays are needed to support clinical diagnosis and epidemiological investigations. Recently, assays for large-scale detection of total antibodies (total-Ab) and immunoglobulin (Ig) G and M against SARS-CoV-2 antigens have been developed, but there are limited data on the diagnostic accuracy of these assays. This study was a Danish national collaboration and evaluated fifteen commercial and one in-house anti-SARS-CoV-2 assays in sixteen laboratories. Sensitivity was evaluated using 150 samples from individuals with asymptomatic, mild or moderate COVID-19; nonhospitalized or hospitalized, confirmed by nucleic acid amplification tests (NAAT), collected 13-73 days either from symptom onset or from positive NAAT (patients without symptoms). Specificity and cross reactivity were evaluated in samples collected prior to the SARS-CoV-2 epidemic from >586 blood donors and patients with autoimmune diseases, cytomegalovirus or Epstein-Barr virus infections and acute viral infections. A specificity of ≥99% was achieved by all total-Ab and IgG assays except one, Diasorin/LiaisonXL-IgG (97.2%). Sensitivities in descending order were: Wantai/ELISA total-Ab (96.7%), CUH-NOVO/in-house ELISA total-Ab (96.0%), Ortho/Vitros total-Ab (95.3%), YHLO/iFlash-IgG (94.0%), Ortho/Vitros-IgG (93.3%), Siemens/Atellica total-Ab (93.2%), Roche/Elecsys total-Ab (92.7%), Abbott/Architect-IgG (90.0%), Abbott/Alinity-IgG (median 88.0%), Diasorin/LiaisonXL-IgG (median 84.6%), Siemens/Vista total-Ab (81.0%), Euroimmun/ELISA-IgG (78.0%), and Snibe/Maglumi-IgG (median 78.0%). However, confidence intervals overlapped for several assays. The IgM results were variable, with the Wantai/ELISA-IgM showing the highest sensitivity (82.7%) and specificity (99%). The rate of seropositivity increased with time from symptom onset and symptom severity.

scholarly journals Validation of the Procalcitonin Assay on the Abbott Architect i1000

2019 ◽  
Vol 3 (6) ◽  
pp. 936-942 ◽  
Author(s):  
Jayson V Pagaduan ◽  
Estella Tam ◽  
Sridevi Devaraj
Keyword(s):  
Statistical Analysis ◽  
Method Validation ◽  
Turnaround Time ◽  
Good Precision ◽  
Serum Samples ◽  
Diagnostic Use ◽  
Clinical Laboratories ◽  
The Us ◽  
The Impact ◽  
Abbott Architect

Abstract Background Procalcitonin (PCT) is an emerging biomarker for detecting sepsis. Recently, the US Food and Drug Administration cleared the expanded use of this biomarker for guiding clinicians regarding antibiotic treatment. To our knowledge, there are no published method validations for the Abbott Architect PCT assay. This article will discuss the process of method validation of the B·R·A·H·M·S PCT assay on the Abbott Architect platform. Methods We studied the precision, accuracy, and linearity of the Architect method following the guidance of the Clinical and Laboratory Standards Institute EP5-A2 document. Furthermore, we also tested the impact of major sources of interference from hemolysate, lipoproteins, and bilirubin. To validate the Architect method, we compared patients' serum PCT measurements with our previously established Mini VIDAS (bioMerieux) PCT assay. Results Statistical analysis showed that the 2 assays have good correlation (r > 0.99), slope of 1.023, and intercept of −0.760. The calculated bias is −7.435%. The Architect method showed good precision with %CV < 3.5% for both interassay and intraassay compared with %CV < 6.5% for Mini VIDAS, which was previously determined at our institution. No bias >10% was observed with the Architect method when pooled serum samples were spiked with interferants. The turnaround time for both platforms was the same (20 min); however, in contrast with Mini VIDAS, the Architect system has automated pipetting of samples and can perform multiple assays simultaneously. Conclusion These results showed that the Architect B·R·A·H·M·S PCT assay has analytical characteristics conducive for diagnostic use in clinical laboratories. Our method validation report will be beneficial for other institutions to adapt this assay on existing Abbott Architect i1000 immunoassay analyzers.

scholarly journals EVALUATION OF ELEVEN IMMUNOCHROMATOGRAPHIC ASSAYS FOR SARS-CoV-2 DETECTION: INVESTIGATING DENGUE CROSS-REACTION

2020 ◽  
Author(s):  
Beatriz Araujo Oliveira ◽  
Lea Campos de Oliveira ◽  
Franciane Mendes de Oliveira ◽  
Geovana Maria Pereira ◽  
Regina Maia de Souza ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
High Sensitivity ◽  
Diagnostic Techniques ◽  
Cross Reactivity ◽  
Cross Reaction ◽  
List Type ◽  
Rt Pcr ◽  
Serum Samples ◽  
Igm Antibodies ◽  
Good Agreement

AbstractBackgroundCOVID-19 disease (Coronavirus disease 2019) caused by SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) is widespread worldwide, affecting more than 11 million people globally (July 6th, 2020). Diagnostic techniques have been studied in order to contain the pandemic. Immunochromatographic (IC) assays are feasible and low cost alternative for monitoring the spread of COVID-19 in the population.MethodsHere we evaluate the sensitivity and specificity of eleven different immunochromatographic tests in 98 serum samples from confirmed cases of COVID-19 through RT-PCR and 100 negative serum samples from blood donors collected in February 2019. Considering the endemic situation of Dengue in Brazil, we also evaluated the cross-reactivity with Dengue using 20 serum samples from patients with confirmed diagnosis for Dengue collected in early 2019 through four different tests.ResultsOur results demonstrated agreement between immunochromatographic assays and RT-PCR, especially after 10 days since the onset of symptoms. The evaluation of IgG and IgM antibodies combined demonstrated a strong level of agreement (0.85) of IC assays and RT-PCR. It was observed cross-reactivity between Dengue and COVID-19 using four different IC assays for COVID-19 diagnosis. The specificity of IC assays to detected COVID-19 IgM antibodies using Dengue serum samples varied from 80% to 85%; the specificity of IgG detection was 100% and total antibody was 95%.ConclusionsWe found high sensitivity, specificity and good agreement of IC assays, especially after 10 days onset of symptoms. However, we detected cross-reactivity between Dengue and COVID-19 mainly with IgM antibodies demonstrating the need for better studies about diagnostic techniques for these diseases.HighlightsImmunochromatographic assays demonstrated high sensitivity and specificity and good agreement with the gold-standard RT-PCR;Increase in sensitivity and specificity of assays using samples collected after the 10th day of symptoms;Cross-reaction with Dengue serology in evaluation of IgM.

A rapid, sensitive enzyme-linked immunoassay for human thyrotropin.

1985 ◽  
Vol 31 (7) ◽  
pp. 1131-1134 ◽  
Author(s):  
Y C Tseng ◽  
K D Burman ◽  
J R Baker ◽  
L Wartofsky
Keyword(s):  
Color Change ◽  
Clinical Laboratory ◽  
High Sensitivity ◽  
Normal Subjects ◽  
Turnaround Time ◽  
Cross Reactivity ◽  
Serum Samples ◽  
Assay Sensitivity ◽  
Nitrophenyl Phosphate ◽  
Set Up

Abstract In this enzyme-linked immunoassay for human thyrotropin (TSH) in unextracted serum we use 96-well immunoenzymometric assay plates, first coated with polyclonal antibody to TSH, then incubated with the serum samples and reacted with mouse monoclonal antibody to human TSH. After incubation with alkaline phosphatase-labeled antibody against mouse IgG, disodium p-nitrophenyl phosphate is added and the color change is measured spectrophotometrically. Assay sensitivity is 0.1 milli-int. unit/L. Cross reactivity with lutropin, follitropin, or choriogonadotropin was negligible. TSH concentrations ranged from 0.4 to 4.1 milli-int. units/L in 43 normal subjects (mean 2.0, SD 1.0), and were uniformly less than 0.3 milli-int. unit/L in 23 patients with hyperthyroidism. Features which make this assay advantageous to the clinical laboratory include ease of set-up, ability to assay many samples at a time, high sensitivity, rapid turnaround time (8 h), and absence of requirements for radioactive materials.

scholarly journals Heterologous Expression, Purification, and Immunological Reactivity of a Recombinant HSP60 from Paracoccidioides brasiliensis

2002 ◽  
Vol 9 (2) ◽  
pp. 374-377 ◽  
Author(s):  
Daniela A. Cunha ◽  
Roseli M. Zancopé-Oliveira ◽  
M. Sueli ◽  
S. Felipe ◽  
Silvia M. Salem-Izacc ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Recombinant Protein ◽  
Paracoccidioides Brasiliensis ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Antibody Responses ◽  
Healthy Individuals ◽  
Immunological Reactivity ◽  
Serum Samples ◽  
Recombinant Antigens

ABSTRACT The complete coding cDNA of HSP60 from Paracoccidioides brasiliensis was overexpressed in an Escherichia coli host to produce high levels of recombinant protein. The protein was purified by affinity chromatography. A total of 169 human serum samples were tested for reactivity by Western blot analysis with the purified HSP60 recombinant protein. Immunoblots indicated that the recombinant P. brasiliensis HSP60 was recognized by antibodies in 72 of 75 sera from paracoccidioidomycosis patients. No cross-reactivity was detected with individual sera from patients with aspergillosis, sporotrichosis, cryptococcosis, and tuberculosis. Reactivity to HSP60 was observed in sera from 9.52% of control healthy individuals and 11.5% of patients with histoplasmosis. The high sensitivity and specificity (97.3 and 92.5%, respectively) for HSP60 suggested that the recombinant protein can be used singly or in association with other recombinant antigens to detect antibody responses in P. brasiliensis-infected patients.

Validation of commercial assays for measurements of trefoil factor family peptides in serum

2011 ◽  
Vol 49 (12) ◽  
Author(s):  
Mie H. Samson ◽  
Ebba Nexo
Keyword(s):  
Blood Donors ◽  
Reference Intervals ◽  
Cross Reactivity ◽  
Serum Concentrations ◽  
Trefoil Factor ◽  
Serum Samples ◽  
Measuring Range ◽  
Trefoil Peptides ◽  
Pathological Conditions ◽  
Trefoil Factor Family

AbstractTrefoil peptides (TFF1, TFF2 and TFF3) are 7–12 kDa molecules, secreted by mucin-producing epithelial cells. Increased serum concentrations have been reported in a number of pathological conditions, which warrants the need for validated commercially available assays.We validated commercial assays for TFF1-3 and compared results obtained with our in-house assays, using serum from blood donors.Level of detection was: ≤0.008 nmol/L. Measuring ranges were: 0.032–0.51 (TFF1), 0.038–0.76 (TFF2) and 0.019–0.15 (TFF3) nmol/L. Imprecision (CV), judged from the measurement of serum pools in two levels, was below 9% (TFF2 and TFF3) but up to 18% (mean 0.41 nmol/L) for TFF1. No cross reactivity between the TFFs (concentrations >100 nmol/L) was observed. The 95% non-parametric reference intervals were: <0.0032–0.53 (TFF1), 0.099–1.4 (TFF2) and 0.086–0.87 (TFF3) nmol/L. Comparing commercial to in-house assays (n=132), showed biases explained by differences in the calibrators (TFF1 and TFF2). A number of samples showed markedly different results.The commercial assays for TFF2 and TFF3 are acceptable for use on serum samples, while the TFF1 assay revealed a poor imprecision and a too narrow measuring range. Results obtained with the commercial and the in-house assays differed, partly because of differences in the calibrators employed.

scholarly journals Specific Serodiagnosis of Canine Visceral Leishmaniasis Using Leishmania Species Ribosomal Protein Extracts

2009 ◽  
Vol 16 (12) ◽  
pp. 1774-1780 ◽  
Author(s):  
Eduardo A. F. Coelho ◽  
Laura Ramírez ◽  
Mariana A. F. Costa ◽  
Vinicio T. S. Coelho ◽  
Vivian T. Martins ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Ribosomal Proteins ◽  
High Sensitivity ◽  
Leishmania Species ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Canine Visceral Leishmaniasis ◽  
Leishmania Chagasi ◽  
Serum Samples ◽  
Potential Tool

ABSTRACT In the present work, we have analyzed the antigenicity of Leishmania species ribosomal proteins (LRPs). To accomplish this, Leishmania infantum ribosomes were biochemically purified from promastigote cytosolic extracts, and their reactivities were analyzed by using the sera from dogs naturally infected with L. infantum. Since antibodies reacting against different ribosomal proteins were observed in all the serum samples obtained from dogs with symptomatic visceral leishmaniasis tested, we have analyzed the potential usefulness of the LRP extracts in the development of an enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of canine visceral leishmaniasis (CVL) in an area of Brazil where visceral leishmaniasis is endemic due to infection by Leishmania chagasi. A comparative ELISA with crude soluble Leishmania chagasi antigen (SLA) and L. infantum LRPs was performed. LRP- and SLA-based ELISAs gave similar sensitivities for the diagnosis of symptomatic CVL, but the LRP extract provided a very high sensitivity for the detection of oligosymptomatic and asymptomatic dogs. In addition, an LRP-based ELISA showed a higher specificity when the sera from dogs harboring other infections were included in the analysis. The LRP antigen displayed no cross-reactivity with sera from dogs that had any of the other diseases tested, notably, Chagas' disease. Our findings suggest that LRPs are a potential tool for the diagnosis of CVL and will be particularly useful for the diagnosis of asymptomatic CVL.

scholarly journals Development of in-house, indirect ELISAs for the detection of SARS-CoV-2 spike protein-associated serology in COVID-19 patients in Panama

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257351
Author(s):  
Carolina de la Guardia ◽  
Giselle Rangel ◽  
Alcibiades Villarreal ◽  
Amador Goodridge ◽  
Patricia L. Fernández ◽  
...  
Keyword(s):  
Area Under The Curve ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Spike Protein ◽  
Close Relative ◽  
Rt Pcr ◽  
Characteristic Analysis ◽  
Serum Samples ◽  
Health Authorities ◽  
Significant Difference

COVID-19 is the name of the acute respiratory disease caused by the new coronavirus SARS-CoV-2, a close relative of those that caused the severe outbreaks of SARS and MERS several years ago. Since first appearance on December of 2019, the COVID-19 pandemic has cause extremely high levels of mortality, morbidity, global economic breakdown, and the consequent human suffering. The main diagnostic test for the confirmation of symptomatic individuals is the detection of viral RNA by reverse transcriptase–quantitative real time PCR (RT-PCR). Additionally, serology techniques, such as ELISA are useful to measure the antibodies produced in humans after contact with the virus, as well as the direct presence of viral antigens. In this study we aim to assemble and evaluate four ELISA assays to measure the presence of IgG or IgM specific for the viral Spike protein in COVID-19 patients, using either the full recombinant SARS-CoV-2 Spike protein or the fragment corresponding to the receptor binding domain. As a control, we analyzed a group of pre-pandemic serum samples obtained before 2017. Strong reactivity was observed against both antigens. A few pre-pandemic samples displayed high OD values, suggesting the possibility of some cross reactivity. All four assays show very good repeatability, both intra- and inter-assay. Receiver operating characteristic analysis allowed the definition of cutoffs and evaluation of performance for each ELISA by estimation of the area under the curve. This performance parameter was high for all tests (AUC range: 0.98–0.99). Multiple comparisons between tests revealed no significant difference between each other (P values: 0.24–0.95). Our results show that both antigens are effective to detect both specific IgG and IgM antibodies, with high sensitivity (range 0.92–0.99), specificity (range 0.93–0.97) and congruence with the RT-PCR test (Cohen´s Kappa range 0.87–0.93). These assays will allow health authorities to have a new tool to estimate seroprevalence, in order to manage and improve the severe sanitary situation caused by this virus.

scholarly journals A high-throughput microsphere-based immunoassay of anti-SARS-CoV-2 IgM testing for COVID-19 diagnostics

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0248444
Author(s):  
Dayu Zhang ◽  
Tianyang Xu ◽  
Eric Chu ◽  
Aiguo Zhang ◽  
Jinwei Du ◽  
...  
Keyword(s):  
High Throughput ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Antibody Detection ◽  
Serum Samples ◽  
Igg Antibody ◽  
Igm Antibody ◽  
Percent Agreement ◽  
Novel Coronavirus ◽  
The Individual

The pandemic of novel coronavirus disease COVID-19 is rapidly expanding across the world. A positive result of antibody tests suggests that the individual has potentially been exposed to SARS-CoV-2, thus allowing to identify asymptomatic infections and determine the seroprevalence in a given population. The aim of this study was to evaluate the performances of a newly developed high throughput immunoassay for anti-SARS-CoV-2 IgM antibody detection on the Luminex MAGPIX platform. Clinical agreement studies were performed in 42 COVID-19 patient serum samples and 162 negative donor serum/plasma samples. Positive percent agreement (PPA) was 42.86% (95% CI: 9.90% to 81.59%), 71.43% (95% CI: 29.04% to 96.33%), and 28.57% (95% CI: 13.22% to 48.67%) for samples collected on 0–7 days, 8–14 days, and 2–8 weeks from symptom onset, respectively. Negative Percent Agreement (NPA) was 97.53% (95% CI: 93.80% to 99.32%). There was no cross-reactivity with the SARS-CoV-2 IgG antibody. Hemoglobin (200 mg/dL), bilirubin (2 mg/dL), triglyceride (250 mg/dL) and EDTA (10 mM) showed no significant interfering effect on this assay. In conclusion, an anti-SARS-CoV-2 IgM antibody assay with high sensitivity and specificity has been developed. With the high throughput, this assay will speed up the anti-SARS-CoV-2 IgM testing.

scholarly journals A High-throughput Microsphere-based Immunoassay of Anti-SARS-CoV-2 IgM Testing for COVID-19 Diagnostics

2021 ◽  
Author(s):  
Dayu Zhang ◽  
Tianyang Xu ◽  
Eric Chu ◽  
Aiguo Zhang ◽  
Jinwei Du ◽  
...  
Keyword(s):  
High Throughput ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Antibody Detection ◽  
Serum Samples ◽  
Igg Antibody ◽  
Igm Antibody ◽  
Percent Agreement ◽  
Novel Coronavirus ◽  
The Individual

ABSTRACTThe pandemic of novel coronavirus disease COVID-19 is rapidly expanding across the world. A positive result of antibody tests suggests that the individual has potentially been exposed to SARS-CoV-2, thus allowing to identify asymptomatic infections and determine the seroprevalence in a given population. The aim of this study was to evaluate the performances of a newly developed high throughput immunoassay for anti-SARS-CoV-2 IgM antibody detection on the Luminex MAGPIX platform. Clinical agreement studies were performed in 42 COVID-19 patient serum samples and 162 negative donor serum/plasma samples. Positive percent agreement (PPA) was 42.86% (95% CI: 9.90% to 81.59%), 71.43% (95% CI: 29.04% to 96.33%), and 28.57% (95% CI: 13.22% to 48.67%) for samples collected on 0-7 days, 8-14 days, and 2-8 weeks from symptom onset, respectively. Negative Percent Agreement (NPA) was 97.53% (95% CI: 93.80% to 99.32%). There was no cross-reactivity with the SARS-CoV-2 IgG antibody Hemoglobin (200 mg/dL), bilirubin (2 mg/dL), triglyceride (250 mg/dL) and EDTA (10 mM) showed no significant interfering effect on this assay. In conclusion, an anti-SARS-CoV-2 IgM antibody assay with high sensitivity and specificity has been developed. With the high throughput, this assay will speed up the anti-SARS-CoV-2 IgM testing.

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