scholarly journals Evaluation of Three Commercial SARS-CoV-2 Serologic Assays and Their Performance in Two-Test Algorithms

2020 ◽  
Vol 59 (1) ◽  
pp. e01892-20 ◽  
Author(s):  
Sarah E. Turbett ◽  
Melis Anahtar ◽  
Anand S. Dighe ◽  
Wilfredo Garcia Beltran ◽  
Tyler Miller ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Predictive Value ◽  
Antibody Test ◽  
Spike Protein ◽  
Serum Samples ◽  
Public Health Decision ◽  
Health Decision ◽  
Test Algorithm ◽  
The Individual ◽  
Antibody Tests

ABSTRACTSensitive and specific severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serologic assays are needed to inform diagnostic, therapeutic, and public health decision-making. We evaluated three commercial serologic assays as stand-alone tests and as components of two-test algorithms. Two nucleocapsid antibody tests (Abbott IgG and Roche total antibody) and one spike protein antibody test (DiaSorin IgG) were included. We assessed sensitivity using 128 serum samples from symptomatic PCR-confirmed coronavirus disease 2019 (COVID-19)-infected patients and specificity using 1,204 samples submitted for routine serology prior to COVID-19’s emergence, plus 64 pandemic-era samples from SARS-CoV-2 PCR-negative patients with respiratory symptoms. Assays were evaluated as stand-alone tests and as components of a two-test algorithm in which positive results obtained using one assay were verified using a second assay. The two nucleocapsid antibody tests were more sensitive than the spike protein antibody test overall (70% and 70% versus 57%; P ≤ 0.003), with pronounced differences observed using samples collected 7 to 14 days after symptom onset. All three assays were comparably sensitive (≥89%; P ≥ 0.13) using samples collected >14 days after symptom onset. Specificity was higher using the nucleocapsid antibody tests (99.3% and 99.7%) than using the spike protein antibody test (97.8%; P ≤ 0.002). When any two assays were paired in a two-test algorithm, the specificity was 99.9% (P < 0.0001 to 0.25 compared with the individual assays), and the positive predictive value (PPV) improved substantially, with a minimal effect on the negative predictive value (NPV). In conclusion, two nucleocapsid antibody tests outperformed a spike protein antibody test. Pairing two different serologic tests in a two-test algorithm improves the PPV, compared with the individual assays alone, while maintaining the NPV.

scholarly journals Evaluation of the Abbott Architect, Roche Elecsys and Virtus S1 SARS-CoV-2 antibody tests in community-managed COVID-19 cases

2020 ◽  
Author(s):  
Sebastian L. Johnston ◽  
Paul F McKay ◽  
Tatiana Kebadze ◽  
Kai Hu ◽  
Karnyart Samnuan ◽  
...  
Keyword(s):  
Antibody Test ◽  
Research Centre ◽  
Strong Positive Correlation ◽  
True Positive ◽  
Antibody Testing ◽  
Serum Samples ◽  
True Negative ◽  
Health And Social Care ◽  
Antibody Tests ◽  
Abbott Architect

AbstractBackgroundAntibody testing can help define how protective immunity to SARS-CoV-2 is and how long this immunity lasts. Many antibody tests have been evaluated in hospitalised rather than community based COVID-19 cases. Virtus Respiratory Research Ltd (Virtus) has developed its own quantitative IgM and IgG SARS CoV-2 antibody assay. We report its validation and performance characteristics and compare its performance with the Abbott Architect and Roche Elecsys assays in community COVID cases.MethodsWe developed a quantitative antibody test to detect IgM and IgG to the SARS-CoV-2 S1 spike protein (the Virtus test) and validated this test in 107 “true positive” sera from 106 community-managed and 1 hospitalised COVID-19 cases and 208 “true negative” serum samples. We validated the Virtus test against a neutralising antibody test. We determined sensitivities of the Abbott test in the 107 true positive samples and the Roche test in a subset of 75 true positive samples.ResultsThe Virtus quantitative test was positive in 93 of 107 (87%) community cases of COVID-19 and both IgM and IgG levels correlated strongly with neutralising antibody titres (r=0.75 for IgM, r=0.71 for IgG, P<0.0001 for both antibodies). The specificity of the Virtus test was 98.6% for low level antibody positives, 99.5% for moderate positives and 100% for high or very high positives. The Abbott test had a sensitivity of 68%. In the 75 sample subset, the Virtus test was positive in 91%, the Roche test in 69%.ConclusionsThe Abbott and Roche tests had sensitives of 68% and 69% respectively in this community set of COVID-19 sera, while the Virtus test had sensitivities of 87% and 91% in the same sample sets. The strong positive correlation with virus neutralization suggests a positive Virtus quantitative antibody test is likely predictive of protective against recurrent COVID-19.FundingThe development of the Virtus test and sample testing with all antibody tests was funded by Virtus Respiratory Research Ltd. The research studies providing 111 of the 208 of the “true negative” samples was supported by MRC Grant numbers MR/M025330/1 and G1100238 and by the National Institute of Health Research (NIHR) Imperial Biomedical Research Centre (BRC), SLJ is a NIHR Emeritus Senior Investigator and is funded in part by European Research Council Advanced Grant 788575 and the Asthma UK Clinical Chair (grant CH11SJ). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.

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.

scholarly journals Tandem Use of OvMANE1 and Ov-16 ELISA Tests Increases the Sensitivity for the Diagnosis of Human Onchocerciasis

Life ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1284
Author(s):  
Cabirou Mounchili Shintouo ◽  
Stephen Mbigha Ghogomu ◽  
Robert Adamu Shey ◽  
An Hotterbeekx ◽  
Emel Yagmur ◽  
...  
Keyword(s):  
Democratic Republic Of Congo ◽  
Serological Test ◽  
Antibody Test ◽  
Onchocerca Volvulus ◽  
Serum Samples ◽  
Positive Skin ◽  
Travel History ◽  
Control Programs ◽  
Potential Biomarker ◽  
Antibody Tests

The current serological test for human onchocerciasis relies on IgG4 reactivity against the parasite Ov-16 antigen, with reported sensitivities of only 60–80%. As control programs move from control to elimination, it is imperative to identify novel molecules that could improve the serodiagnosis reliability of this disease. In this study we compared the sensitivity of total IgG against OvMANE1—a chimeric antigen previously identified as a potential biomarker of human onchocerciasis—with that of an Ov-16 antibody test to detect an Onchocerca volvulus infection in persons presenting with microfilaria in skin snips. One hundred and ninety serum samples were obtained from persons with epilepsy in an onchocerciasis-endemic area at Ituri in the Democratic Republic of Congo where ivermectin has never been distributed. Fifty-nine (31.1%) samples were from individuals with a positive skin snip test; 41 (69.5%) of these 59 samples were positive with the OvMANE1 test and 41 (69.5%) with the Ov-16 test; 30 (50.8%) samples were positive for both tests and in 52 (88.1%) at least one of the tests was positive. Testing the 131 sera from persons with a negative skin snip result revealed that 63 (48.1%) were positive exclusively with the OvMANE1 test, 13 (9.9%) exclusively with the Ov-16 test and 25 (19.1%) with both tests. Nine European samples from individuals without past travel history in onchocerciasis endemic zones and 15 samples from Rwanda, a hypoendemic country for onchocerciasis were all negative for the OvMANE1 and Ov-16 tests. However, the specificity of both tests was difficult to determine due to the lack of a gold standard for antibody tests. In conclusion, the tandem use of OvMANE1 and Ov-16 tests improves the sensitivity of detecting Onchocerca volvulus seropositive individuals but, the OvMANE1 test needs to be further evaluated on samples from a population infected with other helminths to cautiously address its specificity.

DETEKSI ANTIBODI MULTIPEL HEPATITIS C DALAM DARAH DONOR

2016 ◽  
Vol 21 (3) ◽  
pp. 261
Author(s):  
Ranti Permatasari ◽  
Aryati Aryati ◽  
Budi Arifah
Keyword(s):  
Hepatitis C ◽  
Predictive Value ◽  
Core Protein ◽  
Rapid Test ◽  
Antibody Test ◽  
Diagnostic Value ◽  
Hcv Infection ◽  
Antibody Detection ◽  
Hcv Rna ◽  
Hcv Antibody

Hepatitis C (HCV) infection could be spread by blood transfusion. Screening of HCV in donor blood could prevent HCV infection to the recipient. HCV antibody test using rapid test of multiple antibody detection by immunochromatography method is an easy and rapid test that could detect four HCV antibodies separately. The aim of this study was to evaluate the diagnostic value of antibody HCV using multiple antibody detection rapid test in diagnosing HCV infection. This was an analytical observational study with a cross sectional design. The samples consisted of 42 donors’ blood serum from the Surabaya Branch of the Indonesian Red Cross which underwent HCV infection test using ELISA method. The samples were then tested using PCR HCV RNA as the gold standard and antibody HCV multiple antibodydetection rapid test The diagnostic value of HCV antibody test using multiple antibody detection rapid test by immunochromatography method showed a diagnostic sensitivity of 100%, diagnostic specificity of 75%, positive predictive value of 66.7% and negative predictive value of 100%, a diagnostic efficiency of 83.3%, with a positive probability ratio of 4 times. The most often positive antibody pattern was four (4) positive antibodies (core protein, NS3, NS4 and NS5). Core protein (CP) and NS3 were the most often positive antibodies. Based on this study result, the HCV antibody test using multiple antibody detection rapid test by immunochromatography method has a good diagnostic value.

Persons with Disabilities and Public Health Ethics

2019 ◽  
pp. 218-231
Author(s):  
Monika Mitra ◽  
Linda Long-Bellil ◽  
Robyn Powell
Keyword(s):  
Public Health ◽  
Health Policy ◽  
Public Health Policy ◽  
Ethical Issues ◽  
The United States ◽  
Policy And Practice ◽  
Persons With Disabilities ◽  
Public Health Decision ◽  
Health Decision ◽  
Health Policy And Practice

This chapter draws on medical, social, and legal perspectives to identify and highlight ethical issues pertaining to the treatment, representation, and inclusion of persons with disabilities in public health policy and practice. A brief history of disability in the United States is provided as a context for examining the key ethical issues related to public health policy and practice. Conceptual frameworks and approaches to disability are then described and applied. The chapter then discusses the imperativeness of expanding access to public health programs by persons with disabilities, the need to address implicit and structural biases, and the importance of including persons with disabilities in public health decision-making.

scholarly journals Evaluation of Production Lots of a Rapid Point-of-Care Lateral Flow Serological Test Intended for Identification of IgM and IgG against the N-Terminal Part of the Spike Protein (S1) of SARS-CoV-2

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1043
Author(s):  
Tove Hoffman ◽  
Linda Kolstad ◽  
Bengt Rönnberg ◽  
Åke Lundkvist
Keyword(s):  
Predictive Value ◽  
Serological Test ◽  
Point Of Care ◽  
External Validation ◽  
High Sensitivity ◽  
Lateral Flow ◽  
Spike Protein ◽  
Individual Level ◽  
Lateral Flow Test ◽  
Production Errors

The potential of rapid point-of-care (POC) tests has been subject of doubt due to an eventual risk of production errors. The aim was therefore to evaluate the two separate production lots of a commercial POC lateral flow test, intended for the detection of IgM and IgG against the SARS-CoV-2 spike protein (S1). Control samples consisted of serum from individuals with confirmed SARS-CoV-2 infection and pre-COVID-19 negative sera gathered from a biobank. The presence of anti-S1 IgM/IgG in the sera was verified by an in-house Luminex-based serological assay (COVID-19 SIA). One hundred samples were verified as positive for anti-S1 IgG and 74 for anti-S1 IgM. Two hundred samples were verified as negative for anti-S1 IgM/IgG. For the two lots of the POC-test, the sensitivities were 93.2% and 87.8% for IgM and 93.0% and 100% for IgG. The specificities were 100% for IgM and 99.5% for IgG. The positive predictive value was 100% for IgM and 98.9% and 99.0% for IgG. The negative predictive value was 97.6% and 95.7% for IgM, and 96.6% and 100% for IgG. The evaluated POC-test is suitable to assess anti-SARS-CoV-2 S1 IgM and IgG, as a measure of previous virus exposure on an individual level. The external validation of separate lots of rapid POC-tests is encouraged to ensure high sensitivity before market introduction.

scholarly journals THU0296 PROTEIN PROFILING IN INDIVIDUALS BEFORE ONSET OF ANCA-ASSOCIATED VASCULITIS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 376.2-376
Author(s):  
E. Berglin ◽  
A. Esberg ◽  
J. Dahlqvist ◽  
J. Sjöwall ◽  
A. Lundquist ◽  
...  
Keyword(s):  
Immune System ◽  
Growth Factor ◽  
Random Forest ◽  
Symptom Onset ◽  
Partial Least Square ◽  
Protein Profiling ◽  
Serum Samples ◽  
Anca Associated Vasculitis ◽  
Significant Difference ◽  
Novel Biomarkers

Background:Etiology and pathogenesis of ANCA-associated vasculitis (AAV) is multifactorial and understanding of the processes leading from a healthy immune system to autoimmunity and on to debut of symptoms in AAV is rudimentary.Objectives:To identify inflammatory proteins related to the early processes preceding AAV development, and potential novel biomarkers, using large-scale protein analysesMethods:The Swedish National Patient Register of in-patient carevand the Swedish Cause of Death Register with discharge diagnosis from ICD-9 and-10 for AAV were co-analysed with the registers of 4 different blood biobanks to identify AAV individuals with available samples predating onset of symptom. Of the pre-AAV cases 86 (36 male, 50 female; mean age (SD); 51.9 (16.9) years) were identified with at least one plasma or serum sample (28 plasma, and 100 serum) pre-dating symptom onset (mean (SD); -4.3 (3.1) years), and 14 had 2-3 samples. Serum and plasma control samples matched for sex, age and sampling date were identified (n=198; 82 male, 116 female; mean age (SD); 51.9±15.9 years). The samples were analysed for levels of 92 proteins using proximity extension assay (OLINK inflammation panel, SciLifeLab, Uppsala, Sweden). Data were analysed using routine statistical methods, random forest and Partial Least square-discriminant analysis (PLS-DA).Results:As previously described for the assay significant difference between plasma and serum samples were observed both in pre-AAV individuals and controls. In pre-AAV plasma samples significantly increased concentrations of interleukin (IL)-2, chemokine ligand (CCL)-4, fibroblast growth factor (FGF)21, IL-4 and CCL20 were found closer to symptom onset, (<5 years) than later (> 5 years) and compared with controls. In serum tumor necrosis factor receptor superfamily member (TNFRSF)9, CXCL9, osteoprotegerin and vascular endothelial growth factor-A were significantly increased <5 years before onset vs. later (>5 years) and compared with controls. PLS-DA score scattered plot separated the pre-AAV individuals from healthy controls (R2=0.26), with significantly increased levels of CCL23, CXCL5, and matrix metalloproteinases-1 (MMP-1),transforming growth factor-ß, orosomucoid, en-rage (S100A12) and IL-7 and decreased FGF-19 level in serum. Binary logistic regression analyses comparing tertiles for these proteins confirmed significantly increased odds ratios for disease development of CCL23, CXCL5 and MMP-1. The findings were confirmed in random forest analysis where these factors were among the 20 most discriminatory factors between pre-symptomatic AAV and controls.Conclusion:In serum samples collected years before symptom onset of AAV, proteins involved in immune system activation were increased, suggesting that the inflammatory process is initiated long before clinical manifestations of the disease appear. These findings propose the elevated proteins as novel biomarkers for disease progression.References:[1]Watts et al. Ann Rheum Dis 2007;66:222-22Acknowledgments:Vasculitis Foundation, USADisclosure of Interests:Ewa Berglin: None declared, Anders Esberg: None declared, Johanna Dahlqvist: None declared, Johanna Sjöwall: None declared, Anders Lundquist: None declared, Kristina Lejon: None declared, Ingegerd Johansson: None declared, Aladdin J Mohammad Speakers bureau: lecture fees from Roche and Elli Lilly Sweden, PI (GiACTA study), Solbritt Rantapää Dahlqvist: None declared

scholarly journals Automated Assay of a Four-Protein Biomarker Panel for Improved Detection of Ovarian Cancer

Cancers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 325
Author(s):  
Christopher Walker ◽  
Tuan-Minh Nguyen ◽  
Shlomit Jessel ◽  
Ayesha B. Alvero ◽  
Dan-Arin Silasi ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Early Detection ◽  
Predictive Value ◽  
Early Stage ◽  
Ca 125 ◽  
Healthy Controls ◽  
Classification Models ◽  
Serum Samples ◽  
Protein Biomarker ◽  
Biomarker Panel

Background: Mortality from ovarian cancer remains high due to the lack of methods for early detection. The difficulty lies in the low prevalence of the disease necessitating a significantly high specificity and positive-predictive value (PPV) to avoid unneeded and invasive intervention. Currently, cancer antigen- 125 (CA-125) is the most commonly used biomarker for the early detection of ovarian cancer. In this study we determine the value of combining macrophage migration inhibitory factor (MIF), osteopontin (OPN), and prolactin (PROL) with CA-125 in the detection of ovarian cancer serum samples from healthy controls. Materials and Methods: A total of 432 serum samples were included in this study. 153 samples were from ovarian cancer patients and 279 samples were from age-matched healthy controls. The four proteins were quantified using a fully automated, multi-analyte immunoassay. The serum samples were divided into training and testing datasets and analyzed using four classification models to calculate accuracy, sensitivity, specificity, PPV, negative predictive value (NPV), and area under the receiver operating characteristic curve (AUC). Results: The four-protein biomarker panel yielded an average accuracy of 91% compared to 85% using CA-125 alone across four classification models (p = 3.224 × 10−9). Further, in our cohort, the four-protein biomarker panel demonstrated a higher sensitivity (median of 76%), specificity (median of 98%), PPV (median of 91.5%), and NPV (median of 92%), compared to CA-125 alone. The performance of the four-protein biomarker remained better than CA-125 alone even in experiments comparing early stage (Stage I and Stage II) ovarian cancer to healthy controls. Conclusions: Combining MIF, OPN, PROL, and CA-125 can better differentiate ovarian cancer from healthy controls compared to CA-125 alone.

scholarly journals Leptospirosis in Ruminants in Yogyakarta, Indonesia: A Serological Survey with Mixed Methods to Identify Risk Factors

2021 ◽  
Vol 6 (2) ◽  
pp. 84
Author(s):  
Dyah Ayu Widiasih ◽  
Johanna Frida Lindahl ◽  
Wayan T. Artama ◽  
Adi Heru Sutomo ◽  
Pande Made Kutanegara ◽  
...  
Keyword(s):  
Risk Factor ◽  
Management Practices ◽  
Small Ruminants ◽  
Case Fatality ◽  
Open Water ◽  
Serum Samples ◽  
Public Health Importance ◽  
Group Discussions ◽  
The Individual ◽  
And Behavior

Leptospirosis is a zoonotic disease occurring worldwide with reproductive symptoms and production losses in livestock, while humans can suffer fatal renal failure. In Yogyakarta Special Province, Indonesia, there have been several outbreaks with high case fatality, demonstrating the public health importance, but there is limited understanding of the epidemiology. This study used an EcoHealth approach to ensure transdisciplinarity and community participation. Seroprevalence of Leptospira in animals was studied between October 2011 and May 2013 in 15 villages. Serum samples from 1404 cattle and 60 small ruminants were screened by a Microscopic Agglutination Test (MAT), first in pools, and then the individual positive samples were identified. Focus group discussions including farmers, village officials, and official stakeholders were used to explore knowledge and behavior of zoonotic diseases, particularly leptospirosis. Two small ruminants were seropositive for Leptospira icterohemorrhagiae. From the cattle, 3.7% were seropositive, and the most common serovars were Leptospira hardjo, followed by L. icterohemorrhagiae. Out of all farms, 5.6% had at least one positive cattle. Risk factor analyses showed that the risk of the farm being seropositive increased if the farmer used water from an open source, or if farming was not the main occupation. This study showed the presence of Leptospira spp. in ruminants in Yogyakarta and identified use of open water as a risk factor for the livestock. We also observed that the knowledge related to leptospirosis was low, and risky farm management practices were commonly employed.

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