scholarly journals Histoplasmosis-Associated Cross-Reactivity in the BioRad Platelia Aspergillus Enzyme Immunoassay

2007 ◽  
Vol 14 (5) ◽  
pp. 638-640 ◽  
Author(s):  
L. Joseph Wheat ◽  
Emily Hackett ◽  
Michelle Durkin ◽  
Patricia Connolly ◽  
Ruta Petraitiene ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Experimental Infection ◽  
False Positive ◽  
Second Generation ◽  
Cross Reactivity ◽  
Positive Results

ABSTRACT We observed false-positive results in the Platelia Aspergillus enzyme-linked immunoassay (EIA) for specimens from patients with histoplasmosis and mice with experimental infection. Platelia Aspergillus EIA-positive specimens were negative in the second-generation Histoplasma antigen EIA. Care must be taken to exclude histoplasmosis for patients with positive Platelia Aspergillus EIA results.

scholarly journals Galactoxylomannan Does Not Exhibit Cross-Reactivity in the Platelia Aspergillus Enzyme Immunoassay

2007 ◽  
Vol 14 (5) ◽  
pp. 624-627 ◽  
Author(s):  
Magdia De Jesus ◽  
Emily Hackett ◽  
Michelle Durkin ◽  
Patricia Connolly ◽  
Arturo Casadevall ◽  
...  
Keyword(s):  
Positive Result ◽  
Enzyme Immunoassay ◽  
Cryptococcus Neoformans ◽  
Experimental Infection ◽  
False Positive ◽  
Cross Reactivity ◽  
False Positive Result ◽  
Clinical Specimens ◽  
Cross Reactions

ABSTRACT Given the recent report of a false-positive result in the Platelia Aspergillus enzyme immunoassay in a patient with cryptococcosis and in yeast extracts and purified galactoxylomannan of Cryptococcus neoformans, we evaluated culture extracts, purified polysaccharides, clinical specimens, and specimens from animals following experimental infection. Our results revealed no cross-reactions.

Low Rate of False-Positive Results with Use of A Rapid HIV Test

2002 ◽  
Vol 23 (6) ◽  
pp. 335-337 ◽  
Author(s):  
Cassandra D. Salgado ◽  
Heidi L. Flanagan ◽  
Doris M. Haverstick ◽  
Barry M. Farr
Keyword(s):  
Enzyme Immunoassay ◽  
False Positive ◽  
Diagnostic System ◽  
Rapid Test ◽  
Occupational Exposures ◽  
High Rate ◽  
Negative Results ◽  
Hiv Test ◽  
Rapid Hiv Test ◽  
Positive Results

Background:Occupational exposure to human immunodeficiency virus (HIV) is an important threat to healthcare workers. Centers for Disease Control and Prevention guidelines recommend prompt institution of prophylaxis. This requires (1) immediate prophylaxis after exposure, pending test results that may take more than 24 hours in many hospitals; or (2) performance of a rapid test. The Single Use Diagnostic System (SUDS)® HIV-1 Test is used to screen rapidly for antibodies to HIV type 1 in plasma or serum, with a reported sensitivity of more than 99.9%. We used this test from January 1999 until September 2000, when it was withdrawn from the market following reports claiming a high rate of false-positive results.Methods:We reviewed the results of postexposure HIV testing during 21 months.Results:A total of 884 SUDS tests were performed on source patients after occupational exposures (883 negative results, 1 reactive result). The results of repeat SUDS testing on the reactive specimen were also reactive, but the results of enzyme immunoassay and Western blot testing were negative. A new specimen from the same patient showed a negative result on SUDS testing. This suggested a specificity of 99.9%. In the 4 months after SUDS testing was suspended, there was 1 false-positive result on enzyme immunoassay for 1 of 132 source patients (presumed specificity, 99.2%).Conclusion:Use of the SUDS test facilitated rapid and accurate evaluation of source specimens, obviating unnecessary prophylaxis.

scholarly journals False-Positive Results Obtained with the Alexon ProSpecT Cryptosporidium Enzyme Immunoassay

1999 ◽  
Vol 37 (5) ◽  
pp. 1582-1583 ◽  
Author(s):  
Kirk M. Doing ◽  
Jill L. Hamm ◽  
Jo Ann Jellison ◽  
Jessica A. Marquis ◽  
Cindy Kingsbury
Keyword(s):  
Enzyme Immunoassay ◽  
False Positive ◽  
Antigen Detection ◽  
Immunocompromised Patients ◽  
Careful Attention ◽  
Iodine Staining ◽  
Negative Results ◽  
Food Borne ◽  
Positive Results

Cryptosporidium is known to cause diarrhea in immunocompromised patients and is also associated with outbreaks of disease due to food-borne and waterborne parasites. Traditional procedures, involving iodine staining of wet mounts of stool sediments and trichrome staining, lack the sensitivity to detectCryptosporidium. Special staining procedures, such as the modified acid-fast and safranin stains, are generally employed. Less labor-intensive antigen detection assays have simplified detection; however, careful attention to local epidemiology is important because false-positive tests occur. Here, we report two incidents involving 62 false-positive results obtained with the Alexon ProSpecTCryptosporidium enzyme immunoassay, which were deemed false-positive based on negative results obtained from extensive microscopic examinations.

scholarly journals Cross-reactivity of SARS-CoV-2 with HIV chemiluminescent assay leading to false-positive results

2020 ◽  
pp. jclinpath-2020-206942
Author(s):  
Shaun S Tan ◽  
Ka Lip Chew ◽  
Sharon Saw ◽  
Roland Jureen ◽  
Sunil Sethi
Keyword(s):  
False Positive ◽  
Cross Reactivity ◽  
Positive Results

scholarly journals Updated Clinical Evaluation of the CLUNGENE® Rapid COVID-19 Antibody Test

Healthcare ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1124
Author(s):  
Christopher C. Lamb ◽  
Fadi Haddad ◽  
Christopher Owens ◽  
Alfredo Lopez-Yunez ◽  
Marion Carroll ◽  
...  
Keyword(s):  
False Positive ◽  
Point Of Care ◽  
Rapid Test ◽  
Antibody Test ◽  
Cross Reactivity ◽  
Blood Collection ◽  
Rt Pcr ◽  
Antibody Testing ◽  
Reactivity Study ◽  
Positive Results

Background: COVID-19 antibody testing has been shown to be predictive of prior COVID-19 infection and an effective testing tool. The CLUNGENE® SARS-COV-2 VIRUS (COVID-19) IgG/IgM Rapid Test Cassette was evaluated for its utility to aide healthcare professionals. Method: Two studies were performed by using the CLUNGENE® Rapid Test. (1) An expanded Point-of-Care (POC) study at two clinical sites was conducted to evaluate 99 clinical subjects: 62 positive subjects and 37 negative subjects were compared to RT-PCR, PPA, and NPA (95% CI). Sensitivity was calculated from blood-collection time following symptom onset. (2) A cross-reactivity study was performed to determine the potential for false-positive results from other common infections. Results: The specificity of subjects with confirmed negative COVID-19 by RT-PCR was 100% (95% CI, 88.4–100.0%). The sensitivity of subjects with confirmed positive COVID-19 by RT-PCR was 96.77% (95% CI, 88.98–99.11%). In the cross-reactivity study, there were no false-positive results due to past infections or vaccinations unrelated to the SARS-CoV-2 virus. Conclusion: There is a need for a rapid, user-friendly, and inexpensive on-site monitoring system for diagnosis. The CLUNGENE® Rapid Test is a useful diagnostic test that provides results within 15 min, without high-complexity laboratory instrumentation.

scholarly journals Flavivirus Cross-Reactivity to Dengue Nonstructural Protein 1 Antigen Detection Assays

Diagnostics ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 11
Author(s):  
Li Kiang Tan ◽  
Wing Yan Wong ◽  
Hui Ting Yang ◽  
Roland G. Huber ◽  
Peter J. Bond ◽  
...  
Keyword(s):  
False Positive ◽  
Yellow Fever Virus ◽  
Nonstructural Protein ◽  
Cross Reactivity ◽  
Clinical Samples ◽  
Viral Loads ◽  
Rapid Assays ◽  
Nonstructural Protein 1 ◽  
Ns1 Antigen ◽  
Positive Results

Dengue virus (DENV) and Zika virus (ZIKV) are flaviviruses of public health relevance. Both viruses circulate in the same endemic settings and acute infections generally manifest similar symptoms. This highlights the importance of accurate diagnosis for clinical management and outbreak control. One of the commonly used acute diagnostic markers for flaviviruses is nonstructural protein 1 (NS1). However, false positives due to antigenic cross-reactivity have been reported between DENV and ZIKV infections when using DENV NS1 antigen (NS1 Ag) detection assays in acute cases. Therefore, we investigated the lowest detectable virus titres and cross-reactivity of three commercial dengue NS1 Ag rapid assays and two ELISAs for different flaviviruses. Our results showed that substantially high viral titres of ZIKV, Kunjin virus (KUNV) and yellow fever virus (YFV) are required to give false-positive results when using DENV NS1 rapid detection assays. Commercial DENV NS1 ELISAs did not react with ZIKV and YFV. In comparison, tested assays detected DENV at a significantly low virus titre. Given the relatively low viral loads reported in clinical samples, our findings suggest that commercially available dengue NS1 Ag detection assays are less likely to generate false-positive results among clinical samples in areas where multiple flaviviruses cocirculate.

False positive amphetamines and 3,4-methylenedioxymethamphetamine immunoassays in the presence of metoprolol—two cases reported in clinical toxicology

2019 ◽  
Vol 44 (2) ◽  
pp. 200-205 ◽  
Author(s):  
Marion Leclercq ◽  
Marion Soichot ◽  
Brigitte Delhotal-Landes ◽  
Emmanuel Bourgogne ◽  
Hervé Gourlain ◽  
...  
Keyword(s):  
False Positive ◽  
Parent Drug ◽  
Cross Reactivity ◽  
Molecular Structures ◽  
Gas Chromatography Mass Spectrometry ◽  
Medication History ◽  
In Vitro Investigation ◽  
Urine Drug ◽  
Positive Results

Abstract Amphetamines, frequently used recreational drugs with high risk of toxicity, are commonly included in urine drug screens. This screening is based on enzyme immunoassay, which is a quick and easy-to-perform technique, but may lack specificity resulting from cross-reactivity with other compounds, causing false positive results. We present two cases of presumed false positive MULTIGENT® amphetamine/methamphetamine and MULTIGENT® ecstasy (Abbott®) immunoassays with the beta-blocker metoprolol. Both metoprolol-poisoned patients presented positive urine screening despite no history of drug abuse. No confirmation for amphetamine molecular structures was found with gas chromatography–mass spectrometry. The cross-reactivity was further investigated by doping urine samples with metoprolol and its two major phase-I metabolites. Metoprolol showed positive results for both amphetamine and MDMA tests at low concentrations (200 and 150 μg/mL, respectively). Metoprolol metabolites cross-reacted with the amphetamines immunoassay only, but at higher concentrations (i.e., 2000 μg/mL for α-hydroxymetoprolol and 750 μg/mL for O-demethylmetoprolol). In conclusion, false positive results in amphetamines and MDMA immunoassays are possible in the presence of metoprolol. Toxicologists should be aware of frequent analytical interferences with immunoassays and a detailed medication history should be taken into consideration for interpretation. In vitro investigation of suspected cross-reactivity should include not only the parent drug but also its related metabolites.

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