scholarly journals SARS-CoV-2 Serologic Assays in Control and Unknown Populations Demonstrate the Necessity of Virus Neutralization Testing

2020 ◽  
Author(s):  
Jennifer A Rathe ◽  
Emily A Hemann ◽  
Julie Eggenberger ◽  
Zhaoqi Li ◽  
Megan L Knoll ◽  
...  
Keyword(s):  
Predictive Value ◽  
Nucleocapsid Protein ◽  
Antibody Test ◽  
Negative Control ◽  
Virus Neutralization ◽  
Antibody Detection ◽  
Antibody Testing ◽  
Neutralization Activity ◽  
Viral Neutralization ◽  
Virus Specific Antibody

Abstract Background To determine how serologic antibody testing outcome links with virus neutralization of SARS-CoV-2, we evaluated a unique set of individuals for SARS-CoV-2 antibody level and viral neutralization. Methods We compared serum Ig levels across platforms of viral antigens and antibodies with 15 positive and 30 negative SARS-CoV-2 controls followed by viral neutralization assessment. We then applied these platforms to a clinically relevant cohort of 114 individuals with unknown histories of SARS-CoV-2 infection. Results In controls, the best performing virus-specific antibody detection platforms were SARS-CoV-2 receptor binding domain (RBD) IgG [specificity 87%, sensitivity 100%, positive predictive value (PPV) 100%, negative predictive value (NPV) 93%], spike IgG3 [specificity 93%, sensitivity 97%, PPV 93%, NPV 97%], and nucleocapsid protein (NP) IgG [specificity 93%, sensitivity 97%, PPV 93%, NPV 97%]. Neutralization of positive and negative control sera showed 100% agreement. 20 unknown individuals had detectable SARS-CoV-2 antibodies with 16 demonstrating virus neutralization. Spike IgG3 provided the highest accuracy for predicting serologically positive individuals with virus neutralization activity [Misidentified 1/20 unknowns compared to 2/20 for RBD and NP IgG]. Conclusion The coupling of virus neutralization analysis to a spike IgG3 antibody test is optimal to categorize patients for correlates of SARS-CoV-2 immune protection status.

scholarly journals SARS-CoV-2 Serologic Assays in Control and Unknown Populations Demonstrate the Necessity of Virus Neutralization Testing.

2020 ◽  
Author(s):  
Jennifer A Rathe ◽  
Emily A Hemann ◽  
Julie Eggenberger ◽  
Zhaoqi Li ◽  
Megan Knoll ◽  
...  
Keyword(s):  
Antibody Test ◽  
Negative Control ◽  
Virus Neutralization ◽  
Antibody Detection ◽  
Immune Protection ◽  
Antibody Testing ◽  
Viral Neutralization ◽  
Positive Antibody ◽  
Antibody Assays ◽  
Focus Reduction

Background: To determine how serologic antibody testing outcome links with virus neutralization of SARS-CoV-2 to ascertain immune protection status, we evaluated a unique set of individuals for SARS-CoV-2 antibody detection and viral neutralization. Methods: Herein, we compare several analytic platforms with 15 positive and 30 negative SARS-CoV-2 infected controls followed by viral neutralization assessment. We then applied these platforms in a clinically relevant population: 114 individuals with unknown histories of SARS-CoV-2 infection. Results: In control populations, the best performing antibody detection assays were SARS-CoV-2 receptor binding domain (RBD) IgG (specificity 87%, sensitivity 100%, PPV 100%, NPV 93%), spike IgG3 (specificity 93%, sensitivity 97%, PPV 93%, NPV 97%), and nucleocapsid (NP) protein IgG (specificity 93%, sensitivity 97%, PPV 93%, NPV 97%). Neutralization of positive and negative control sera showed 100% agreement. 20 unknown individuals had detectable SARS-CoV-2 antibodies with 16 demonstrating virus neutralization. The antibody assays that best predicted virus neutralization were RBD IgG (misidentified 2), spike IgG3 (misidentified 1), and NP IgG (misidentified 2). Conclusion: These data suggest that meaningful evaluation of antibody assay performance requires testing in an unknown population. Further, these results indicate coupling of virus neutralization analysis to a positive antibody test is required to categorize patients based on SARS-CoV-2 immune protection status following virus exposure or vaccine administration. One of the antibody detection platforms identified in this study followed by the pseudoneutralization or focus reduction assay would provide a practical testing strategy to assess for SARS-CoV-2 antibodies with optimal prediction of correlates to neutralizing immunity.

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.

An evaluation of the performance of OraQuick® ADVANCE Rapid HIV-1/2 Test in a high-risk population attending genitourinary medicine clinics in East London, UK

2008 ◽  
Vol 19 (10) ◽  
pp. 665-667 ◽  
Author(s):  
J Zelin ◽  
N Garrett ◽  
J Saunders ◽  
F Warburton ◽  
J Anderson ◽  
...  
Keyword(s):  
High Risk ◽  
Test Performance ◽  
Predictive Value ◽  
Risk Groups ◽  
Antibody Detection ◽  
High Risk Population ◽  
Antibody Testing ◽  
Observer Error ◽  
The Uk ◽  
Hiv 1

To date, no data have been published on the use of OraQuick® ADVANCE Rapid HIV-1/2 Test (OraQuick) in the UK. We report preliminary findings of an ongoing evaluation of OraQuick in UK genitourinary (GU) medicine clinics. A total of 820 samples from patients in high-risk groups for HIV were tested with OraQuick and results were compared with standard HIV antibody testing. HIV prevalence (enzyme immunoassay [EIA]) was 5.73%, sensitivity of OraQuick was 93.64% (95% CI 82.46–98.66%), specificity 99.87% (99.28–100%), positive predictive value 97.78% (88.27–99.94%) and negative predictive value 99.61% (98.87–99.92%). This includes three false-negatives considered to be due to observer error and now rectified by further training. This has increased test sensitivity to 100%. Our observed test performance of OraQuick compares well with EIA and with other rapid tests. We believe that simple, non-invasive antibody detection tests such as OraQuick can increase HIV testing and diagnosis in UK GU medicine and community settings.

scholarly journals Antibody testing for COVID-19: A report from the National COVID Scientific Advisory Panel

2020 ◽  
Vol 5 ◽  
pp. 139 ◽  
Author(s):  
Emily R. Adams ◽  
Mark Ainsworth ◽  
Rekha Anand ◽  
Monique I. Andersson ◽  
Kathryn Auckland ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Vaccine Development ◽  
Detection Threshold ◽  
Negative Control ◽  
Antibody Detection ◽  
Advisory Panel ◽  
Antibody Testing ◽  
Highly Sensitive ◽  
History Of ◽  
The Uk

Background: The COVID-19 pandemic caused >1 million infections during January-March 2020. There is an urgent need for reliable antibody detection approaches to support diagnosis, vaccine development, safe release of individuals from quarantine, and population lock-down exit strategies. We set out to evaluate the performance of ELISA and lateral flow immunoassay (LFIA) devices. Methods: We tested plasma for COVID (severe acute respiratory syndrome coronavirus 2; SARS-CoV-2) IgM and IgG antibodies by ELISA and using nine different LFIA devices. We used a panel of plasma samples from individuals who have had confirmed COVID infection based on a PCR result (n=40), and pre-pandemic negative control samples banked in the UK prior to December-2019 (n=142). Results: ELISA detected IgM or IgG in 34/40 individuals with a confirmed history of COVID infection (sensitivity 85%, 95%CI 70-94%), vs. 0/50 pre-pandemic controls (specificity 100% [95%CI 93-100%]). IgG levels were detected in 31/31 COVID-positive individuals tested ≥10 days after symptom onset (sensitivity 100%, 95%CI 89-100%). IgG titres rose during the 3 weeks post symptom onset and began to fall by 8 weeks, but remained above the detection threshold. Point estimates for the sensitivity of LFIA devices ranged from 55-70% versus RT-PCR and 65-85% versus ELISA, with specificity 95-100% and 93-100% respectively. Within the limits of the study size, the performance of most LFIA devices was similar. Conclusions: Currently available commercial LFIA devices do not perform sufficiently well for individual patient applications. However, ELISA can be calibrated to be specific for detecting and quantifying SARS-CoV-2 IgM and IgG and is highly sensitive for IgG from 10 days following first symptoms.

scholarly journals Antibody testing for COVID-19: A report from the National COVID Scientific Advisory Panel

2020 ◽  
Author(s):  
◽  
Emily R Adams ◽  
Mark Ainsworth ◽  
Rekha Anand ◽  
Monique I Andersson ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Vaccine Development ◽  
Detection Threshold ◽  
Negative Control ◽  
Antibody Detection ◽  
Advisory Panel ◽  
Antibody Testing ◽  
Highly Sensitive ◽  
History Of ◽  
The Uk

ABSTRACTBackgroundThe COVID-19 pandemic caused >1 million infections during January-March 2020. There is an urgent need for reliable antibody detection approaches to support diagnosis, vaccine development, safe release of individuals from quarantine, and population lock-down exit strategies. We set out to evaluate the performance of ELISA and lateral flow immunoassay (LFIA) devices.MethodsWe tested plasma for COVID (SARS-CoV-2) IgM and IgG antibodies by ELISA and using nine different LFIA devices. We used a panel of plasma samples from individuals who have had confirmed COVID infection based on a PCR result (n=40), and pre-pandemic negative control samples banked in the UK prior to December-2019 (n=142).ResultsELISA detected IgM or IgG in 34/40 individuals with a confirmed history of COVID infection (sensitivity 85%, 95%CI 70-94%), vs. 0/50 pre-pandemic controls (specificity 100% [95%CI 93-100%]). IgG levels were detected in 31/31 COVID-positive individuals tested ≥10 days after symptom onset (sensitivity 100%, 95%CI 89-100%). IgG titres rose during the 3 weeks post symptom onset and began to fall by 8 weeks, but remained above the detection threshold. Point estimates for the sensitivity of LFIA devices ranged from 55-70% versus RT-PCR and 65-85% versus ELISA, with specificity 95-100% and 93-100% respectively. Within the limits of the study size, the performance of most LFIA devices was similar.ConclusionsCurrently available commercial LFIA devices do not perform sufficiently well for individual patient applications. However, ELISA can be calibrated to be specific for detecting and quantifying SARS-CoV-2 IgM and IgG and is highly sensitive for IgG from 10 days following first symptoms.

scholarly journals China NMPA perspective on clinical evaluation of SARS-CoV-2 antibody test reagents in the process of emergency approval

Bioanalysis ◽  
2020 ◽  
Author(s):  
Yunfeng Lv ◽  
Jingyun He ◽  
Rongzhi Liu ◽  
Yu Gao ◽  
Chao Xu ◽  
...  
Keyword(s):  
Early Stage ◽  
Antibody Test ◽  
Standard Test ◽  
Test Method ◽  
Antibody Detection ◽  
Test Results ◽  
Antibody Testing ◽  
National Medical ◽  
Key Points ◽  
Antigen Antibody

Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 antibody testing an important supplement to nucleic acid testing. In the process of emergency approval, the Center for Medical Device Evaluation of the China National Medical Products Administration released The Key Points of Technical Review for the Registration of SARS-CoV-2 Antigen/Antibody Detection Reagents. The Clinical Study Requirement section of the Key Point has put forward requirements in terms of reference methods and subject enrolment among others, which can ensure that the test results can meet the clinical needs. This article draws on the experience of the China NMPA in evaluating diagnostic reagents used to supplement the gold standard test method in the early stage of an epidemic of an infectious disease, as well as to serve as reference for clinicians and regulators.

scholarly journals Use of a screening questionnaire for systemic lupus erythematosus among pregnant women in a Mexican population

2021 ◽  
Vol 8 (1) ◽  
pp. e000486
Author(s):  
Luis Lucero-Morales ◽  
Juanita Romero-Diaz ◽  
Diana Yazmin Copado-Mendoza ◽  
María del Carmen Zamora-Medina ◽  
Sandra Acevedo-Gallegos ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Clinical Assessment ◽  
Lupus Erythematosus ◽  
Predictive Value ◽  
Antinuclear Antibody ◽  
Antibody Test ◽  
Antibody Testing ◽  
Systemic Lupus ◽  
Cross Sectional ◽  
Screening Questionnaire

ObjectiveTo conduct a diagnostic assessment of pregnant women using a screening questionnaire for SLE.Materials and methodsThis was an analytical cross-sectional study carried out at the National Institute of Perinatology between 1 November 2019 and 28 February 2020, using a screening questionnaire for SLE. Antinuclear antibody and anti-double stranded DNA antibody tests and a clinical assessment by a rheumatologist were conducted for participants who obtained ≥4 positive responses on the questionnaire. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the screening questionnaire for SLE were calculated.ResultsThe questionnaire survey was conducted with 540 pregnant patients, 22 of whom (4.1%) had ≥4 positive responses. An antinuclear antibody test was conducted in all aforementioned 22 patients; 17 (77.3%) showed titres of ≥1:80. Of the 22 patients, 19 (86.4%) underwent clinical assessment by a rheumatologist. The patients were classified according to the SLE classification criteria: 7/19 (36.9%) met the revised 1997 American College Rheumatology (ACR) criteria, 8/19 (42.1%) met the Systemic Lupus International Collaborating Clinics criteria and 7/19 (36.9%) met the 2019 ACR/EULAR criteria (sensitivity=0.86, specificity=0.97, PPV=0.77 and NPV=1 for antinuclear antibody titre of ≥1:80; sensitivity=0.88, specificity=0.98, PPV=0.37 and NPV=1 for SLE according to the 2019 ACR/EULAR criteria).ConclusionsThe questionnaire showed high sensitivity and specificity in the diagnosis of SLE. Given its usability and cost:benefit ratio, this strategy should be used for all patients coming in for their first visit to determine who requires antinuclear antibody testing and who needs to be referred to a rheumatologist.

scholarly journals Exploratory field study on the effects of porcine circovirus 2 (PCV-2) sow vaccination at different physiological stages mimicking blanket vaccination

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Patricia Pleguezuelos ◽  
Marina Sibila ◽  
Raúl Cuadrado ◽  
Rosa López-Jiménez ◽  
Diego Pérez ◽  
...  
Keyword(s):  
Quantitative Polymerase Chain Reaction ◽  
Negative Control Group ◽  
Negative Control ◽  
Late Gestation ◽  
Antibody Detection ◽  
Porcine Circovirus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Physiological Status ◽  
Porcine Circovirus 2

Abstract Background The objective of the present study was to explore the benefits of Porcine circovirus 2 (PCV-2) blanket vaccination in a sow herd on productive parameters, PCV-2 infection and immune status in sows and their progeny. For this purpose, 288 sows were distributed among four balanced experimental groups. One group remained as negative control group and the other three received 1 mL of PCV-2 Ingelvac Circoflex® intramuscularly at different productive cycle moments: before mating, mid gestation (42–49 days post-insemination) or late gestation (86–93 days post-insemination); phosphate buffered saline (PBS) was used as negative control item. Reproductive parameters from sows during gestation and body weight of their progeny from birth to weaning were recorded. Additionally, blood was collected from sows at each vaccination time and piglets at 3 weeks of age. Moreover, up to 4 placental umbilical cords (PUC) per sow were taken at peri-partum. Sera from sows and piglets were analysed for PCV-2 antibody detection using an enzyme-linked immunosorbent assay (ELISA). Sera from sows and PUC were tested to quantify viraemia using a real time quantitative polymerase chain reaction (qPCR) assay. Results Globally, results indicated that vaccinated sows showed heavier piglets at birth and at weaning, less cross-fostered piglets, lower viral load at farrowing as well as in PUC, and higher antibody levels at farrowing, compared to non-vaccinated ones. When all groups were compared among them, sows vaccinated at mid or late gestation had heavier piglets at birth than non-vaccinated sows, and lower proportion of PCV-2 positive PUC. Also, cross-fostering was less frequently practiced in sows vaccinated at pre-mating or mid gestation compared to non-vaccinated ones. Conclusions In conclusion, the present study points out that PCV-2 sow vaccination at different time points of their physiological status (mimicking blanket vaccination) offers benefits at production and serological and virological levels.

A Nationwide Survey of COVID-19 Testing in LGBTQ+ Populations in the United States

2021 ◽  
pp. 003335492110181
Author(s):  
Richard J. Martino ◽  
Kristen D. Krause ◽  
Marybec Griffin ◽  
Caleb LoSchiavo ◽  
Camilla Comer-Carruthers ◽  
...  
Keyword(s):  
United States ◽  
Gay Men ◽  
Antibody Test ◽  
Nationwide Survey ◽  
The United States ◽  
Sociodemographic Characteristics ◽  
Full Time ◽  
Test Results ◽  
Antibody Testing ◽  
And Gender

Objectives Lesbian, gay, bisexual, transgender, or queer and questioning (LGBTQ+) people and populations face myriad health disparities that are likely to be evident during the COVID-19 pandemic. The objectives of our study were to describe patterns of COVID-19 testing among LGBTQ+ people and to differentiate rates of COVID-19 testing and test results by sociodemographic characteristics. Methods Participants residing in the United States and US territories (N = 1090) aged ≥18 completed an internet-based survey from May through July 2020 that assessed COVID-19 testing and test results and sociodemographic characteristics, including sexual orientation and gender identity (SOGI). We analyzed data on receipt and results of polymerase chain reaction (PCR) and antibody testing for SARS-CoV-2 and symptoms of COVID-19 in relation to sociodemographic characteristics. Results Of the 1090 participants, 182 (16.7%) received a PCR test; of these, 16 (8.8%) had a positive test result. Of the 124 (11.4%) who received an antibody test, 45 (36.3%) had antibodies. Rates of PCR testing were higher among participants who were non–US-born (25.4%) versus US-born (16.3%) and employed full-time or part-time (18.5%) versus unemployed (10.8%). Antibody testing rates were higher among gay cisgender men (17.2%) versus other SOGI groups, non–US-born (25.4%) versus US-born participants, employed (12.6%) versus unemployed participants, and participants residing in the Northeast (20.0%) versus other regions. Among SOGI groups with sufficient cell sizes (n > 10), positive PCR results were highest among cisgender gay men (16.1%). Conclusions The differential patterns of testing and positivity, particularly among gay men in our sample, confirm the need to create COVID-19 public health messaging and programming that attend to the LGBTQ+ population.

scholarly journals Human Immunodeficiency Virus Antibody Testing by Enzyme-Linked Fluorescent and Western Blot Assays Using Serum, Gingival-Crevicular Transudate, and Urine Samples

1999 ◽  
Vol 37 (4) ◽  
pp. 1100-1106 ◽  
Author(s):  
Prudencio Martínez Martínez ◽  
Antonio Rodríguez Torres ◽  
Raul Ortiz de Lejarazu ◽  
Ana Montoya ◽  
José Francisco Martín ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Hiv Infection ◽  
Western Blot ◽  
Stage Iv ◽  
Urine Samples ◽  
World Health ◽  
Antibody Detection ◽  
Lower Sensitivity ◽  
Antibody Testing ◽  
Immunodeficiency Virus

The aim of the present study was to evaluate the possible utilization of saliva and urine as alternative samples to serum for the diagnosis of human immunodeficiency virus (HIV) infection. A total of 302 individuals participated in the study: 187 HIV-infected individuals (106 had Centers for Disease Control and Prevention [CDC] stage II infection, 19 had CDC stage III infection, and 62 had CDC stage IV infection) and 115 noninfected persons (46 of the noninfected persons were blood donors and 69 belonged to a group at high risk of HIV infection). Paired saliva and urine samples were taken from each of the participants in the study. The presence of HIV-specific antibodies was detected by an enzyme-linked fluorescent assay (ELFA), and the result was confirmed by Western blot analysis (WB). The ELFA with saliva gave maximum sensitivity and specificity values, while ELFA had lower sensitivity (95.2%) and specificity (97.4%) values for detection of HIV antibody in urine samples. WB with all saliva samples fulfilled the World Health Organization criterion for positivity, while only 96.8% of the urine samples were confirmed to be positive by WB. Among the four reactivity patterns found by WB of these alternative samples, the most frequent included bands against three groups of HIV structural proteins (was ENV, POL, and GAG). The reactivity bands most frequently observed were those for the proteins gp160 and gp120. The least common reactivity band was the band for protein p17. The detection of HIV antibodies in saliva samples by means of ELFA with the possibility of later confirmation by WB makes saliva an alternative to serum for possible use in the diagnosis of infection. In contrast, HIV antibody detection in urine samples by the same methodology (ELFA) could be taken into consideration for use in epidemiological studies.

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