scholarly journals Radioligand Assay-Based Detection of Antibodies against SARS-CoV-2 in Hospital Workers Treating Patients with Severe COVID-19 in Japan

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 347
Author(s):  
Hidenori Matsunaga ◽  
Akiko Makino ◽  
Yasuhiro Kato ◽  
Teruaki Murakami ◽  
Yuta Yamaguchi ◽  
...  
Keyword(s):  
General Hospital ◽  
Blood Donor ◽  
Neutralizing Antibody ◽  
Radioligand Assay ◽  
Inpatient Settings ◽  
Negative Controls ◽  
Blood Donor Sample ◽  
Donor Sample ◽  
Antibody Tests ◽  
Positive Results

This study aimed to clarify whether infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is prevalent among the staff of a hospital providing treatment to patients with severe coronavirus disease 2019 (COVID-19) using radioligand assay (RLA). One thousand samples from the staff of a general hospital providing treatment to patients with severe COVID-19 were assayed for SARS-CoV-2 nucleocapsid protein (N) IgG using RLA. Nine patients with COVID-19 who had been treated in inpatient settings and had already recovered were used as control subjects, and 186 blood donor samples obtained more than 10 years ago were used as negative controls. Four of the 1000 samples showed apparently positive results, and approximately 10 or more samples showed slightly high counts. Interestingly, a few among the blood donor samples also showed slightly high values. To validate the results, antibody examinations using ELISA and neutralizing antibody tests were performed on 21 samples, and chemiluminescence immunoassay (CLIA) was performed on 201 samples, both resulting in a very high correlation. One blood donor sample showed slightly positive results in both RLA and CLIA, suggesting a cross-reaction. This study showed that five months after the pandemic began in Japan, the staff of a general hospital with a tertiary emergency medical facility had an extremely low seroprevalence of the antibodies against SARS-CoV-2. Further investigation will be needed to determine whether the slightly high results were due to cross-reactions or a low titer of anti-SARS-CoV-2 antibodies. The quantitative RLA was considered sensitive enough to detect low titers of antibodies.

Four new mutations in the BCHE gene of human butyrylcholinesterase in a Brazilian blood donor sample

2005 ◽  
Vol 84 (4) ◽  
pp. 349-353 ◽  
Author(s):  
Ricardo L.R. Souza ◽  
Liya R. Mikami ◽  
Rodrigo O.B. Maegawa ◽  
Eleidi A. Chautard-Freire-Maia
Keyword(s):  
Blood Donor ◽  
Blood Donor Sample ◽  
Donor Sample ◽  
Brazilian Blood Donor ◽  
Human Butyrylcholinesterase ◽  
New Mutations

scholarly journals Commercial Serology Assays Predict Neutralization Activity Against SARS-CoV-2

2020 ◽  
Author(s):  
Raymond T Suhandynata ◽  
Melissa A Hoffman ◽  
Deli Huang ◽  
Jenny T Tran ◽  
Michael J Kelner ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Positive Serology ◽  
Neutralization Activity ◽  
Antibody Titers ◽  
Negative Controls ◽  
First Time ◽  
The Relationship ◽  
Positive Results

Background. Currently it is unknown whether a positive serology results correlates with protective immunity against SARS-CoV-2. There are also concerns regarding the low positive predictive value of SARS-CoV-2 serology tests, especially when testing populations with low disease prevalence. Methods. A neutralization assay was validated in a set of PCR confirmed positive specimens and in a negative cohort. 9,530 specimens were screened using the Diazyme SARS-CoV-2 IgG serology assay and all positive results (N=164) were reanalyzed using the neutralization assay, the Roche total immunoglobin assay, and the Abbott IgG assay. The relationship between the magnitude of a positive SARS-CoV-2 serology result and the levels of neutralizing antibodies detected was correlated. Neutralizing antibody titers (ID50) were also longitudinally monitored in SARS-CoV-2 PCR confirmed patients. Results. The SARS-CoV-2 neutralization assay had a PPA of 96.6% with a SARS-CoV-2 PCR test and a NPA of 98.0% across 100 negative controls. ID50 neutralization titers positively correlated with all three clinical serology platforms. Longitudinal monitoring of hospitalized PCR confirmed COVID-19 patients demonstrates they made high neutralization titers against SARS-CoV-2. PPA between the Diazyme IgG assay alone and the neutralization assay was 50.6%, while combining the Diazyme IgG assay with either the Roche or Abbott platforms increased the PPA to 79.2% and 78.4%, respectively. Conclusions. For the first time, we demonstrate that three widely available clinical serology assays positively correlate with SARS-CoV-2 neutralization activity observed in COVID-19 patients. When a two-platform screen and confirm approach was used for SARS-CoV-2 serology, nearly 80% of two-platform positive specimens had neutralization titers (ID50 >50).

Clinical aspects and detection of Zika virus RNA in several tissues of experimentally infected BALB/c mice

2020 ◽  
Author(s):  
Derick Mendes Bandeira ◽  
Gabriela Cardoso Caldas ◽  
Fernanda Cunha Jácome ◽  
Arthur da Costa Rasinhas ◽  
Ana Luisa Teixeira de Almeida ◽  
...  
Keyword(s):  
Zika Virus ◽  
Scientific Literature ◽  
Rna Extraction ◽  
Clinical Signs ◽  
Clinical Aspects ◽  
Virus Rna ◽  
Time Of Infection ◽  
Negative Controls ◽  
Positive Results ◽  
Different Tissues

Abstract The aim of the present study was to infect BALB/c mice with ZIKV to evaluate clinical signs and to quantify the viral load in different tissues at three different kinetic points. For this purpose, fifteen mice were inoculated with a 100µl of a viral solution and five other mice were used as negative controls. After euthanasia, nine different tissues were collected and macerated for RNA extraction and quantification. The infections were not lethal. Some of them, however, showed great agitation, hair bristling and itchy skin. Viral RNA was detected in one heart sample, eight samples of spleen and two of skeletal muscle. Seven out of eleven positive samples were from mice euthanized on the third day after infection. Only spleen yielded positive results at a later time of infection. These results contribute to a better understanding of clinical signs and replication dynamics of Zika virus in different organs of BALB/c mice, which are still scarce data in the scientific literature.

Factors Associated with False-Positive Results from Fingerstick OraQuick ADVANCE Rapid HIV 1/2 Antibody Test

2012 ◽  
Vol 11 (6) ◽  
pp. 356-360 ◽  
Author(s):  
Samara B. Rifkin ◽  
Lauren E. Owens ◽  
Jeffrey L. Greenwald
Keyword(s):  
Risk Factors ◽  
False Positive ◽  
Medical Center ◽  
Antibody Test ◽  
Blood Type ◽  
Factors Associated ◽  
Rapid Tests ◽  
Antibody Tests ◽  
Positive Results ◽  
Hiv 1

Objective: Identify factors associated with false-positive rapid HIV antibody tests. Design: This retrospective cohort study with nested case–controls involved patients tested for HIV by Boston Medical Center (BMC) affiliates. Methods: Cases had a reactive fingerstick OraQuick ADVANCE rapid HIV 1/2 antibody test and a negative Western blot. Controls had nonreactive rapid tests. We compared the prevalence of HIV risk factors between cases and the total nonreactive population and the prevalence of other clinical factors between cases and controls. Results: Of the 15 094 tests, 14 937 (98.9%) were negative and 11 (0.07%) were false positives (specificity of 99.9%). Cases were more likely to have had an HIV-infected sex partner and to be tested at certain sites compared to true negatives. More cases than controls had O-negative blood type. Conclusion: O-negative blood type and sex with an HIV-infected person may increase false-positive HIV fingerstick results. More targeted studies should examine these risk factors.

scholarly journals Commercial Serology Assays Predict Neutralization Activity against SARS-CoV-2

2020 ◽  
Author(s):  
Raymond T Suhandynata ◽  
Melissa A Hoffman ◽  
Deli Huang ◽  
Jenny T Tran ◽  
Michael J Kelner ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Negative Control ◽  
Percentage Agreement ◽  
Positive Serology ◽  
Neutralization Activity ◽  
Antibody Titers ◽  
The Relationship ◽  
Positive Results

Abstract Background It is unknown whether a positive serology result correlates with protective immunity against SARS-CoV-2. There are also concerns regarding the low positive predictive value of SARS-CoV-2 serology tests, especially when testing populations with low disease prevalence. Methods A neutralization assay was validated in a set of PCR-confirmed positive specimens and in a negative cohort. In addition, 9530 specimens were screened using the Diazyme SARS-CoV-2 IgG serology assay and all positive results (N = 164 individuals) were reanalyzed using the neutralization assay, the Roche total immunoglobin assay, and the Abbott IgG assay. The relationship between the magnitude of a positive SARS-CoV-2 serology result and neutralizing activity was determined. Neutralizing antibody titers (50% inhibitory dilution, ID50) were also longitudinally monitored in patients confirmed to have SARS-CoV-2 by PCR. Results The SARS-CoV-2 neutralization assay had a positive percentage agreement (PPA) of 96.6% with a SARS-CoV-2 PCR test and a negative percentage agreement (NPA) of 98.0% across 100 negative control individuals. ID50 neutralization titers positively correlated with all 3 clinical serology platforms. Longitudinal monitoring of hospitalized PCR-confirmed patients with COVID-19 demonstrated they made high neutralization titers against SARS-CoV-2. PPA between the Diazyme IgG assay alone and the neutralization assay was 50.6%, while combining the Diazyme IgG assay with either the Roche or Abbott platforms increased the PPA to 79.2 and 78.4%, respectively. Conclusions These 3 clinical serology assays positively correlate with SARS-CoV-2 neutralization activity observed in patients with COVID-19. All patients confirmed SARS-CoV-2 positive by PCR develop neutralizing antibodies.

Comparison of Serological Tests for the Detection of Natural Heartworm Infection in Cats

2004 ◽  
Vol 40 (5) ◽  
pp. 376-384 ◽  
Author(s):  
Paul Berdoulay ◽  
Julie K. Levy ◽  
Patti S. Snyder ◽  
Michael J. Pegelow ◽  
Jennifer L. Hooks ◽  
...  
Keyword(s):  
Point Of Care ◽  
False Negative ◽  
Serological Tests ◽  
Male Worm ◽  
Single Male ◽  
Commercial Laboratory ◽  
Heartworm Infection ◽  
Antigen Tests ◽  
Antibody Tests ◽  
Positive Results

Serological tests were performed on 380 cats with necropsy-confirmed heartworm status to compare the performance of currently available commercial laboratory and point-of-care heart-worm serological tests in a heartworm-endemic area. Overall, antigen tests detected 79.3% to 86.2% of heartworm infections and were highly specific. Most cats with false-negative antigen tests had a single male worm. Antibody tests detected 62.1% to 72.4% of heartworm infections and had a wider range of false-positive results (1.4% to 19.1%) than antigen tests (0.3% to 2.0%). Serological tests for feline heartworm infection varied in diagnostic performance. Combining results from antigen and antibody tests achieved greater sensitivity than using either test alone.

scholarly journals A SPECIFIC COMPLEMENT-FIXATION TEST FOR INFECTION WITH POLIOMYELITIS VIRUS

1951 ◽  
Vol 94 (2) ◽  
pp. 123-137 ◽  
Author(s):  
Jordi Casals ◽  
Peter K. Olitsky ◽  
Ralph O. Anslow
Keyword(s):  
Complement Fixation Test ◽  
Complement Fixation ◽  
Neutralizing Antibody ◽  
Newborn Mouse ◽  
Newborn Mice ◽  
Poliomyelitis Virus ◽  
Human Sera ◽  
Cotton Rats ◽  
Specific Reactions ◽  
Positive Results

A complement-fixing antigen has been developed, using as source of material CNS tissue from newborn mice infected with the newborn mouse-adapted strain of the Lansing type, MEF1 virus. With this antigen, specific reactions have been obtained with sera from mice, cotton rats, and monkeys immunized with the Lansing-type virus, and from monkeys and chimpanzees convalescent from infection with this virus. Twenty-one of 35 human sera obtained from individuals convalescent from poliomyelitis were positive and 6 of 22 from apparently normal persons having Lansing-neutralizing antibody, while this held true for only 1 of 19 from those having no Lansing-neutralizing antibody. The fact that positive results were found in sera from patients having an infection with poliomyelitis virus of the Brunhilde type and at the same time no Lansing-neutralizing antibody brings up the possibility of the existence of a cross-reaction in complement fixation between the two types.

scholarly journals The occurrence of neutralizing and complement fixing antibodies in rubella

1967 ◽  
Vol 65 (3) ◽  
pp. 409-421 ◽  
Author(s):  
Anne M. Field
Keyword(s):  
General Population ◽  
Rubella Virus ◽  
Complement Fixation ◽  
Neutralizing Antibody ◽  
Recent Infection ◽  
England And Wales ◽  
Congenital Rubella ◽  
Antibody Titres ◽  
Antibody Tests ◽  
Rubella Antibody

Neutralization and complement-fixation tests to detect rubella antibody are described. Results of such tests show that between 80 and 95% of adults in England and Wales have neutralizing antibody. The presence of complement-fixing antibody indicates recent infection with rubella virus.Results are presented showing the development of neutralizing and complement-fixing antibody after rubella.Antibody tests on children with congenital rubella and their mothers are detailed. It is noted that higher neutralizing antibody titres are found in this group than in the general population.

scholarly journals A serological relationship between mumps and sendai viruses

1960 ◽  
Vol 58 (3) ◽  
pp. 283-289 ◽  
Author(s):  
P. S. Gardner
Keyword(s):  
Blood Transfusion ◽  
General Hospital ◽  
Virus Particle ◽  
Blood Donor ◽  
Sendai Virus ◽  
Mumps Virus ◽  
Serological Relationship ◽  
Essential Components ◽  
Antigen Complex

Sixty-six paired sera from patients suffering from mumps were examined with Sendai and mumps virus particle antigen: 50% showed a rise of complementfixing antibodies to mumps virus particle antigen only and the rest to both antigens.This relationship was further substantiated by the occurrence of both antibodies in a proportion of the sera of 362 blood transfusion donors and 978 sera from antenatal patients.The occurrence of both antibodies in patients' sera is discussed and the conclusion is reached that one of the components of the mumps antigen complex is indistinguishable from the essential components of the Sendai virus.I am indebted to the Maternity Department of the Edgware General Hospital for supplying the antenatal sera, and to Dr Preston of the Regional Transfusion Centre, Oxford, for the blood donor sera.

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