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
2007 ◽  
Vol 14 (5) ◽  
pp. 638-640 ◽  
Author(s):  
L. Joseph Wheat ◽  
Emily Hackett ◽  
Michelle Durkin ◽  
Patricia Connolly ◽  
Ruta Petraitiene ◽  
...  

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.


Healthcare ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1124
Author(s):  
Christopher C. Lamb ◽  
Fadi Haddad ◽  
Christopher Owens ◽  
Alfredo Lopez-Yunez ◽  
Marion Carroll ◽  
...  

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.


Diagnostics ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 11
Author(s):  
Li Kiang Tan ◽  
Wing Yan Wong ◽  
Hui Ting Yang ◽  
Roland G. Huber ◽  
Peter J. Bond ◽  
...  

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.


2019 ◽  
Vol 44 (2) ◽  
pp. 200-205 ◽  
Author(s):  
Marion Leclercq ◽  
Marion Soichot ◽  
Brigitte Delhotal-Landes ◽  
Emmanuel Bourgogne ◽  
Hervé Gourlain ◽  
...  

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.


Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1054
Author(s):  
Anna Didkowska ◽  
Monika Krajewska-Wędzina ◽  
Daniel Klich ◽  
Kinga Prolejko ◽  
Blanka Orłowska ◽  
...  

Both bovine tuberculosis (BTB) and paratuberculosis (paraTB) continue to cause significant economic losses in cattle breeding; in addition, their etiological agents have zoonotic potential. Although the diagnostics of both diseases are still being improved, problems still remain, such as the potential for cross-reactivity to the antigens used in tests. The aim of the present study was to confirm whether animals known to harbor Mycobacterium bovis antibodies are at increased risk of yielding positive results in paraTB serotesting and, additionally, to verify the accuracy of three commonly used methods for confirming M. bovis infection: ELISA, the tuberculin skin test (TST), and the presence of gross lesions. Material was collected from 98 dairy cattle suspected of BTB due to TST-positive results. During postmortem examination, gross lesions were assessed visually. Blood, lymph nodes, and TB-suspected organs were collected. Serum was obtained from the collected blood and tested serologically for TB and paraTB. The tissues underwent standard microbiological testing for M. tuberculosis complex. Among the 98 TST-positive individuals, tuberculous gross lesions were detected in 57 (58.1%), MTBC were isolated in 83 (84.7%), and the ELISA test was positive for 21 (21.4%). None of the lesions characteristic for paraTB were detected. The chance of obtaining a positive TB result by ELISA was seven times higher using the ELISA-paraTB method; hence, there is a significant risk of obtaining false-positive serological results for paraTB in M. bovis-infected cattle. However, the hypothesis that infection of M. bovis or prior TST performance may have boosted the host immune response and therefore increased the sensitivity of the paraTB-ELISA cannot be excluded.


2021 ◽  
Vol 7 (6) ◽  
pp. 474
Author(s):  
Tiwa Rotchanapreeda ◽  
Pattarana Sae-Chew ◽  
Tassanee Lohnoo ◽  
Wanta Yingyong ◽  
Thidarat Rujirawat ◽  
...  

Pythiosis, a life-threatening disease caused by Pythium insidiosum, has been increasingly diagnosed worldwide. A recently developed immunochromatographic test (ICT) enables the rapid diagnosis of pythiosis. During the 3-year clinical implementation of ICT in Thailand, we collected the laboratory reports of 38 animals with suspected pythiosis and detected ICT false-positive results in three horses and a dog with basidiobolomycosis. P. insidiosum and Basidiobolus ranarum cause infections with indistinguishable clinical and microscopic features. This study investigated cross-reactive antibodies by probing P. insidiosum and B. ranarum crude extracts and cell-free synthesized I06 protein (encoded in P. insidiosum genome, not other fungi) against a panel of pythiosis, basidiobolomycosis, rabbit anti-I06 peptide, and control sera by Western blot analyses. ICT false-positive results occurred from the cross-reactivity of anti-B. ranarum antibodies to the 15, 50, 60, and 120 kDa proteins of P. insidiosum, not double infections caused by both pathogens. Notably, ICT could help to screen pythiosis, and the positive test requires confirmation by culture or molecular method. The detection specificity of ICT requires improvement. The crude extract containing multispecies antigens needs replacement with a refined P. insidiosum-specific protein. We proposed that the 55 kDa I06 protein is an excellent candidate for developing a more specific serodiagnostic test for pythiosis.


1974 ◽  
Vol 31 (02) ◽  
pp. 273-278
Author(s):  
Kenneth K Wu ◽  
John C Hoak ◽  
Robert W Barnes ◽  
Stuart L Frankel

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.


1995 ◽  
Vol 31 (5-6) ◽  
pp. 403-406 ◽  
Author(s):  
E. Frahm ◽  
U. Obst

Two recently developed Legionella detection tests, a microbiological-immunological method based on monoclonal antibodies (carried out as a colony-blot assay) and a commercial gene-probe testkit (the EnvironAmp Legionella Kit), are compared with the standard method. The colony-blot assay is faster than the conventional method; the gene-probe test is much faster still and is the most sensitive, but in consequence is at greater risk of false-positive results.


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