scholarly journals Evaluation of OIDx Histoplasma Urinary Antigen EIA

2021 ◽  
Author(s):  
Diego Hernando Caceres ◽  
Beatriz L. Gomez ◽  
Angela M. Tobon ◽  
Tom Chilller ◽  
Mark D. Lindsley
Keyword(s):  
Enzyme Immunoassay ◽  
False Positive ◽  
High Sensitivity ◽  
Reference Panel ◽  
Urine Samples ◽  
Urinary Antigen ◽  
Imaging Diagnostics ◽  
Sandwich Enzyme Immunoassay ◽  
Positive Results ◽  
Optimum Imaging

Abstract A sandwich enzyme immunoassay (EIA) for the detection of Histoplasma antigens (Ag) in urine, developed by Optimum Imaging Diagnostics (OIDx) was evaluated. A verification using a standardized reference panel of urine samples found sensitivity of 92%, specificity of 32% and accuracy of 51%. In this study, the OIDx Histoplasma urinary Ag EIA displayed high sensitivity, however, in non-histoplasmosis cases this EIA displayed false-positive results in 68% of specimens tested.

A highly sensitive sandwich enzyme immunoassay of urinary growth hormone in children with short stature, Turner's syndrome, and simple obesity

1989 ◽  
Vol 121 (4) ◽  
pp. 513-519 ◽  
Author(s):  
Hiroshi Tomita ◽  
Masamichi Ogawa ◽  
Takashi Kamijo ◽  
Osamu Mori ◽  
Eiji Ishikawa ◽  
...  
Keyword(s):  
Short Stature ◽  
Enzyme Immunoassay ◽  
Gh Deficiency ◽  
Urine Samples ◽  
Turner's Syndrome ◽  
Turner’S Syndrome ◽  
Highly Sensitive ◽  
Significant Difference ◽  
Simple Obesity ◽  
Sandwich Enzyme Immunoassay

Abstract. GH values were determined by a highly sensitive sandwich enzyme immunoassay in the 1st morning and/or 24-h accumulated urine samples in 94 children (short stature 70, including 14 with complete GH deficiency, 9 with partial GH deficiency, and 47 with GH-normal short stature; Turner's syndrome, 10, and simple obesity, 14). GH values were also determined in the 2nd to 4th urine samples taken on the same day together with the 1st morning urine in 5 of them. GH values in the 1st morning urine correlated significantly with those of the 24-h urine and with serum peak and mean GH values during nocturnal sleep as a physiological GH secretion test. The 2nd to 4th urines had lower GH concentrations than the 1st morning urine. The GH value of the 1st morning urine in complete GH deficiency was significantly lower than those in GH-normal short stature, partial GH deficiency and Turner's syndrome. However, no significant difference was detected in urinary GH values between complete GH deficiency and simple obesity. We conclude that 1st morning urinary GH estimation may be useful for differentiation of complete GH deficiency from other causes of short stature, but may be difficult for the distinction between complete GH deficiency and obesity with normal GH secretory ability.

Three Years of Experience With Random Urinary Homovanillic and Vanillylmandelic Acid Levels in the Diagnosis of Neuroblastoma

PEDIATRICS ◽  
1987 ◽  
Vol 79 (2) ◽  
pp. 203-205
Author(s):  
Mendel Tuchman ◽  
Margaret L. R. Ramnaraine ◽  
William G. Woods ◽  
William Krivit
Keyword(s):  
False Positive ◽  
Homovanillic Acid ◽  
False Negative ◽  
False Negative Rate ◽  
Urine Samples ◽  
Vanillylmandelic Acid ◽  
Test Results ◽  
Upper Limit ◽  
Positive Results ◽  
Rule Out

During the last 3 years, random urine samples from 408 patients were tested for elevated homovanillic acid (HVA) and vanillylmandelic acid (VMA) levels to rule out the diagnosis of neuroblastoma. Thirty-seven of these patients had elevated HVA and/or VMA levels, and neuroblastoma was subsequently diagnosed. In three additional patients with negative test results (normal HVA and VMA levels), tumors were subsequently diagnosed (false-negative rate of 7.5%). Ten percent of the patients with neuroblastoma had normal HVA and 27.5% had normal VMA levels at the time of diagnosis. Only one patient (2.5%) with neuroblastoma had elevated VMA levels in the presence of normal HVA levels. More than 60% of the patients with neuroblastoma had urinary HVA and/or VMA levels higher than twice the upper limit of normal. No false-positive results were encountered. Age and stage distributions of the patients are shown, and the significance of the results is discussed.

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 Comparison of the Binax Legionella Urinary Antigen Enzyme Immunoassay (EIA) with the Biotest Legionella Urin Antigen EIA for Detection of Legionella Antigen in both Concentrated and Nonconcentrated Urine Samples

1998 ◽  
Vol 36 (9) ◽  
pp. 2718-2722 ◽  
Author(s):  
J. A. Domínguez ◽  
N. Galí ◽  
P. Pedroso ◽  
A. Fargas ◽  
E. Padilla ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Legionella Pneumophila ◽  
No Reduction ◽  
Wide Spectrum ◽  
Cross Reactivity ◽  
Culture Collection ◽  
Urine Samples ◽  
Urinary Antigen ◽  
Antigen Present ◽  
Commercial Enzyme Immunoassay

We evaluated a newly commercial enzyme immunoassay (EIA) (BiotestLegionella Urin Antigen EIA; Biotest AG, Dreieich, Germany) for detection of antigens of all Legionella pneumophilaserogroups with a relatively wide spectrum of cross-reactivity as well as antigens of other Legionella spp. by comparing its sensitivity and specificity with those of an EIA for detection ofL. pneumophila serogroup 1 antigen (Legionella urinary antigen EIA; Binax, Portland, Maine). Both tests were performed with both concentrated and nonconcentrated urine samples. We also evaluated the capabilities of both EIAs to detect extracted soluble antigens of American Type Culture Collection (ATCC) Legionella strains (L. pneumophila serogroups 1 to 14, L. bozemanii, and L. longbeachae). The sensitivity of the Biotest EIA was 66.66% in nonconcentrated urine and 86.66% in concentrated urine. The sensitivity of the Binax EIA was 63.76% and 88.88% in nonconcentrated and concentrated urine, respectively. The specificity was 100% in nonconcentrated and concentrated urine for both assays. The Binax EIA and Biotest EIA detected extracted soluble antigens of L. pneumophila serogroups 1 to 14 and L. bozemanii ATCC strains. The cross-reactions observed with the Binax EIA were probably due to common epitopes directly related to lipopolysaccharide. Further studies are required to determine the usefulness of the Binax EIA for detection of urinary antigens fromLegionella species and serogroups other than L. pneumophila serogroup 1. The Biotest EIA proved to be as rapid, sensitive, and specific as the Binax EIA for the diagnosis of legionellosis. Concentration of antigen present in urine increased the sensitivities of both techniques with no reduction in specificity.

scholarly journals Benzene Derivatives from Ink Lead to False Positive Results in Neonatal Hyperphenylalaninemia Screening with Ninhydrin Fluorometric Method

2020 ◽  
Vol 6 (1) ◽  
pp. 14
Author(s):  
Shuren Feng ◽  
Joanne Mei ◽  
Lu Yang ◽  
Ping Luo ◽  
Xiaonan Wang ◽  
...  
Keyword(s):  
False Positive ◽  
High Performance ◽  
Low Cost ◽  
High Sensitivity ◽  
Benzene Derivatives ◽  
Negative Results ◽  
Specimen Collection ◽  
Blood Specimens ◽  
Ethanol Extracts ◽  
Positive Results

Ninhydrin-based fluorometric quantification of phenylalanine is one of the most widely used methods for hyperphenylalaninemia (HPA) screening in neonates due to its high sensitivity, high accuracy, and low cost. Here we report an increase of false positive cases in neonatal HPA screening with this method, caused by contamination of blood specimen collection devices during the printing process. Through multiple steps of verification, the contaminants were identified from ink circles printed on the collection devices to indicate the positions and sizes of blood drops. Blood specimens from HPA-negative persons collected on these contaminated collection devices showed positive results in the fluorometric tests, but negative results in tandem mass spectroscopy (MS/MS) experiments. Contaminants on the collection devices could be extracted by 80% ethanol and showed an absorption peak around 245 nm, suggesting that these contaminants may contain benzene derivatives with similar structure to phenylalanine. High-performance liquid chromatography (HPLC) analysis of the ethanol extracts from contaminated collection devices identified two prominent peaks specifically from the devices. Methyl-2-benzoylbenzoate (MBB, CAS#606-28-0) was found as one of the major chemicals from contaminated collection devices. This report aims to remind colleagues in the field of this potential contamination and call for tighter regulation and quality control of specimen collection devices.

scholarly journals Reevaluation of Commercial Reagents for Detection of Histoplasma capsulatum Antigen in Urine

2015 ◽  
Vol 53 (4) ◽  
pp. 1198-1203 ◽  
Author(s):  
Elitza S. Theel ◽  
Julie A. Harring ◽  
Ala S. Dababneh ◽  
Leonard O. Rollins ◽  
Jeannie E. Bestrom ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Histoplasma Capsulatum ◽  
Urine Samples ◽  
Urinary Antigen ◽  
Content Type ◽  
Rapid Assay ◽  
Positive Agreement ◽  
Assay Protocol

Detection of theHistoplasma capsulatumurinary antigen (UAg) is among the most sensitive and rapid means to diagnose histoplasmosis. Previously, we evaluated analyte-specific reagents (ASR) manufactured by IMMY (Norman, OK) for detection ofHistoplasmagalactomannan (GM) in urine using an enzyme immunoassay (EIA), and we showed low positive agreement (64.5%) with the MiraVista (MVista)Histoplasmaantigen (Ag) quantitative EIA (MiraVista Diagnostics, Indianapolis, IN). Here we reevaluated the IMMY GM ASR following modification of our original assay protocol and introduction of an indeterminate range. A total of 150 prospectively collected urine samples were tested with both the IMMY and MVista EIAs, and clinical histories were recorded for all study subjects. The IMMY GM ASR showed positive and negative agreements of 82.3% (14/17 samples) and 100% (121/121 samples), respectively (with exclusion of 12 indeterminate results), and overall agreement of 90% (135/150 samples) with respect to the MVista EIA. Of the three patients with negative IMMY GM ASR results and positive MVista EIA results, testing was performed for initial diagnostic purposes for one patient (<0.4 ng/ml by the MVista EIA) and UAg levels were being monitored for the remaining two patients (both <0.7 ng/ml by the MVista EIA). The MVista EIA results were positive for 6/12 samples that tested indeterminate by the IMMY GM ASR. We also show that the IMMY GM ASR can be used to serially monitorHistoplasmaUAg levels. In conclusion, we demonstrate that, with modification, the IMMY GM ASR is a reliable rapid assay for detection ofHistoplasmaUAg.

The spot test is not a reliable screening procedure for mucopolysaccharidoses

1991 ◽  
Vol 37 (4) ◽  
pp. 572-575 ◽  
Author(s):  
J G N de Jong ◽  
J J F Hasselman ◽  
A A J van Landeghem ◽  
H L Vader ◽  
R A Wevers
Keyword(s):  
False Positive ◽  
False Negative ◽  
Spot Test ◽  
Urine Samples ◽  
Screening Procedure ◽  
Negative Results ◽  
False Negative Results ◽  
Spot Tests ◽  
Metabolic Screening ◽  
Positive Results

Abstract To check the reliability of the Ames MPS paper spot test, which is based on the Azure A dye, we sent a series of urine samples to three laboratories where the spot test is part of the metabolic screening for mucopolysaccharidoses. In these laboratories false-negative results ranged between 19% and 35% and false-positive results ranged between 12% and 29% of all samples submitted. In contrast, the quantitative dimethylmethylene blue test (Clin Chem 1989;35:1472-7) detected an increased glycosaminoglycan content in all urine samples from mucopolysaccharidosis patients and gave no false-positive results. In the latter procedure, glycosaminoglycan content is expressed per millimole of creatinine, and age-dependent reference values are used. We conclude that the Ames spot test and other spot tests are unreliable as a screening procedure for mucopolysaccharidoses and should not be used to screen for these diseases.

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.

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