scholarly journals Unresolved Discrepancies between Cannabinoid Test Results for Infant Urine

2012 ◽  
Vol 58 (9) ◽  
pp. 1364-1367 ◽  
Author(s):  
Vilte E Barakauskas ◽  
Rebecka Davis ◽  
Matthew D Krasowski ◽  
Gwendolyn A McMillin
Keyword(s):  
Similar Rate ◽  
Urine Samples ◽  
Drug Screen ◽  
Reference Laboratory ◽  
Data Sets ◽  
Independent Data ◽  
Test Results ◽  
Hospital Laboratory ◽  
Positive Screen ◽  
Positive Results

Abstract BACKGROUND False-positive drug screen results for tetrahydrocannabinol (THC) have been observed. This study investigated the rate of unconfirmed positive screen results in infant and noninfant urine samples and evaluated possible reasons for differences. METHODS The rate of unconfirmed positive THC screen results for urine samples was determined retrospectively in 2 independent data sets (n = 14 859, reference laboratory; n = 21 807, hospital laboratory) by comparing positive immunoassay-based drug screen results with the associated results of confirmation tests. We then assessed the rate of positive THC screens for samples with varying likelihoods of cannabinoid presence to evaluate the contribution of infant-specific urine constituents to positive results. Finally, a method to detect a THC metabolite (11-hydroxy-Δ9-THC) that occurs in meconium was developed to determine its prevalence in infant urine. RESULTS Positive screen results failed to confirm more frequently in samples from infants (47%) than in noninfants (0.8%). The hospital laboratory observed a similar discrepancy with a different immunoassay. Infant samples with a high likelihood of containing cannabinoids despite negative confirmatory results had a similar rate of positive screening results (50%, n = 20), whereas all samples with a low likelihood of containing cannabinoids screened negative (n = 23). 11-Hydroxy-Δ9-THC was not detected in any infant urine sample tested (n = 16). CONCLUSIONS Conventional confirmatory methods for THC may be inappropriate for urine samples from infants. Our results suggest that one or more currently unrecognized THC-associated compounds are responsible for positive THC screen results for infant urine, as opposed to an infant-associated interference.

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.

Implementation of a Fully Automated Latex Immunoturbidimetric Assay for the Diagnosis of Heparin-Induced Thrombocytopenia in a High-Volume University Hospital Laboratory

2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S30-S30
Author(s):  
Christina Pierre ◽  
Mary Acker ◽  
Surabhi Palkimas ◽  
Lindsay Bazydlo
Keyword(s):  
High Volume ◽  
Turnaround Time ◽  
University Hospital ◽  
Reference Laboratory ◽  
Platelet Factor ◽  
Heparin Induced Thrombocytopenia ◽  
Hospital Laboratory ◽  
Assay Precision ◽  
Positive Results ◽  
Interassay Precision

Abstract Background Heparin-induced thrombocytopenia (HIT) is an immune-mediated, adverse reaction to heparin in which heparin binds platelet factor 4 (PF4), triggering the development of heparin-PF4 antibodies (HITAb). HITAbs bind and activate platelets, causing thrombosis, platelet consumption, and thrombocytopenia. Heparin is replaced with relatively costly nonheparin anticoagulants until HIT can be ruled out. HIT diagnosis consists of a HITAb immunoassay with reflex to a serotonin release assay (SRA) for confirmation of positive results. Recently, a fully automated latex immunoturbidimetric assay (LIA) for detection of HITAbs received FDA clearance. We sought to verify the performance characteristics of the LIA with the aim of implementing the test in a high-volume university hospital laboratory. Methods The in-house HITAb LIA was performed on the Instrumentation Laboratory TOP700 analyzer using HemosIL HIT-Ab(PF4-H) reagent. The comparator method, a HITAb ELISA, was performed at a reference laboratory with positive results reflexed to SRA. All samples (36 total) sent to the reference laboratory for HIT testing from December 2017 to November 2018 were aliquoted and run in parallel by LIA. Intra-assay precision was assessed by running manufacturer-provided low and high control samples 10 times in succession, while interassay precision was assessed by running low and high samples every day for 10 days. Turnaround time to HITAb result was retrieved from the electronic medical records for HIT testing performed 60 days before and after in-house test implementation. Results The agreement between the LIA and ELISA was 92% (33/36). One discordant sample tested negative by ELISA and was not assessed by SRA. Another tested positive by ELISA and negative by LIA and was confirmed negative by SRA. The final discordant sample tested negative by LIA but positive by ELISA and was confirmed positive by SRA. Thirty-three percent (12/36) of samples tested positive for HITAb by ELISA and were reflexed to SRA. Both the ELISA and LIA showed 83% agreement (10/12) with the SRA. The coefficient of variance (CV) for the intra-assay precision studies was 18% and 5% for the low and high controls, respectively. The CV for the interassay precision studies was 28% and 5% for the low and high controls, respectively. Postimplementation quality control data revealed 61% and 20% imprecision on the low and high level controls, respectively, which declined significantly when reagents were removed from the instrument and refrigerated within 2 hours. The turnaround time for HITAb results was reduced by 74% (10.5 vs 41 hours) after in-house test implementation, significantly reducing the need for administration of nonheparin anticoagulants. Conclusion The LIA and ELISA methods compared favorably, allowing for clinical implementation of the LIA. The shortened turnaround time of the LIA significantly reduced the time to rule out HIT, enhancing patient care and reducing drug costs. The assay imprecision warrants further investigation regarding reagent stability.

scholarly journals Quality Assessment of the Genetic Test for Familial Hypercholesterolemia in The Netherlands

Cholesterol ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Iris Kindt ◽  
Roeland Huijgen ◽  
Marieke Boekel ◽  
Kristiaan J. van der Gaag ◽  
Joep C. Defesche ◽  
...  
Keyword(s):  
The Netherlands ◽  
Familial Hypercholesterolemia ◽  
Screening Program ◽  
Reference Laboratory ◽  
Test Results ◽  
Cascade Screening ◽  
Dna Test ◽  
Increased Risk ◽  
A Prospective Study ◽  
Positive Results

Introduction. Familial hypercholesterolemia (FH) is an inherited disorder associated with a severely increased risk of cardiovascular disease. Although DNA test results in FH are associated with important medical and ethical consequences, data on accuracy of genetic tests is scarce. Methods. Therefore, we performed a prospective study to assess the overall accuracy of the DNA test used in the genetic cascade screening program for FH in The Netherlands. Individuals aged 18 years and older tested for one of the 5 most prevalent FH mutations, were included consecutively. DNA samples were analyzed by the reference and a counter-expertise laboratory following a standardized procedure. Results. 1003 cases were included. In the end, 317 (32%) carried an FH mutation, whereas in 686 (69%) samples no mutation was found. The overall accuracy of the reference laboratory was 99.8%, with two false positive results identified by the counter-expertise laboratory. Conclusion. The currently used mutation analysis is associated with a very low error rate. Therefore, we do not recommend routine use of duplicate testing.

The visual arrays task…visual storage capacity or attention control?

2019 ◽  
Author(s):  
Jessie Martin ◽  
Jason S. Tsukahara ◽  
Christopher Draheim ◽  
Zach Shipstead ◽  
Cody Mashburn ◽  
...  
Keyword(s):  
Working Memory ◽  
Storage Capacity ◽  
Working Memory Capacity ◽  
Memory Capacity ◽  
Attention Control ◽  
Data Sets ◽  
Independent Data ◽  
Visual Storage ◽  
Design Selection ◽  
The Relationship

**The uploaded manuscript is still in preparation** In this study, we tested the relationship between visual arrays tasks and working memory capacity and attention control. Specifically, we tested whether task design (selection or non-selection demands) impacted the relationship between visual arrays measures and constructs of working memory capacity and attention control. Using analyses from 4 independent data sets we showed that the degree to which visual arrays measures rely on selection influences the degree to which they reflect domain-general attention control.

scholarly journals The Wild West of Emergency Use Authorizations for SARS-CoV-2 Testing: What Could Be the True Sensitivity?

2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S142-S143
Author(s):  
S Dalal ◽  
S Patel ◽  
J M Petersen ◽  
D Jhala
Keyword(s):  
Medical Center ◽  
Initial Result ◽  
Reference Laboratory ◽  
Test Results ◽  
Rt Pcr ◽  
Repeat Testing ◽  
Parallel Testing ◽  
Percent Agreement ◽  
Instructions For Use ◽  
Multiple Reference

Abstract Introduction/Objective SARS-CoV-2 is a pandemic that has required mobilization to meet urgent needs. In this mobilization, emergency use authorizations (EUA) have been issued by the FDA to expedite the deployment of these tests. This has led to a situation whereby sensitivity has not been rigorously studied for any of the assays with EUAs. Estimates can be extrapolated from the limited samples documented by the company in their instructions for use (IFU). Although the nationwide shortage of testing reagents prevent parallel testing of multiple platforms on all specimens, observations of repeat specimens at the Veteran Affairs Medical Center (VAMC) provides the first study in the literature of more complete data for SARS-CoV-2 nucleic acid (RT-PCR) assay on sensitivity on the Abbott (Abbott Park Ill) and Cepheid (Sunnyvale CA) assays. Methods A retrospective search was performed for all test results for SARS-CoV-2 by RT-PCR from 3/1/2020 to 4/14/2020 at Corporal Michael J. Crescenz Medical Center, in order to evaluate the sensitivity on Abbott m2000 and Cepheid platforms. Results across multiple reference laboratories and in-house testing platforms were collated in a table with all patients clinically requiring repeat testing recorded. Results 114/863 patients had repeat testing. The tests were performed initially by outside reference laboratories (25 patients), on the Abbott m2000 (63 patients), and Cepheid Infinity (26 patients). 15/114 (13%) had discordant results on repeat testing. This included 1 test initially done by a reference laboratory. 8 days after the initial result from the reference lab, a positive for the same patient was identified on the Abbott platform. 11 initial Abbott results were discordant on further repeat testing on two platforms - Abbott (6 patients) and Cepheid (5 patients) 1-6 days later. In addition, 3 initial Cepheid were discordant on further repeat testing by the same Cepheid platform (1-16 days later). Conclusion While the instructions for use for both platforms suggest 100% sensitivity and specificity (due to the 100% positive and negative percent agreement in limited specimens), the true sensitivity is less than 100%, particularly early in the course of the infection. In our study, the positive percent agreement (surrogate for sensitivity) was 83% for initial Abbott tests, 88% for initial Cepheid tests, and 95% by Reference laboratory platform.

scholarly journals Identification of a robust gene signature that predicts breast cancer outcome in independent data sets

BMC Cancer ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
James E Korkola ◽  
Ekaterina Blaveri ◽  
Sandy DeVries ◽  
Dan H Moore ◽  
E Shelley Hwang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Signature ◽  
Data Sets ◽  
Independent Data ◽  
Breast Cancer Outcome ◽  
Cancer Outcome

Clinical features, treatment, and outcome of dogs with Coccidioides osteomyelitis

2022 ◽  
pp. 1-8
Author(s):  
Stephanie L. Shaver ◽  
Daniel S. Foy ◽  
Todd D. Carter
Keyword(s):  
Electronic Medical Records ◽  
Medical Records ◽  
Clinical Signs ◽  
Test Results ◽  
Serologic Test ◽  
Rapid Improvement ◽  
Radiographic Appearance ◽  
One Year ◽  
Positive Results

Abstract OBJECTIVE To describe signalment, clinical signs, serologic test results, treatment, and outcome of dogs with Coccidioides osteomyelitis (COM) and to compare those findings with findings for dogs with osteosarcoma (OSA). ANIMALS 14 dogs with COM and 16 dogs with OSA. PROCEDURES Data were retrospectively gathered from electronic medical records. RESULTS Dogs with COM were younger and weighed less than dogs with OSA. Six dogs with COM had appendicular lesions, 5 had axial lesions, and 3 had both appendicular and axial lesions; 9 had monostotic disease, and 5 had polyostotic disease. Axial lesions and nonadjacent polyostotic disease were more common in dogs with COM than in dogs with OSA, but radiographic appearance was not different between the 2 groups. Median IgG titer at diagnosis of COM was 1:48 and was significantly decreased after 6 and 12 months of treatment. Percentage of dogs with COM that had clinical signs was significantly decreased after 1, 3, 6, and 12 months of treatment. One year after initiation of treatment, 9 of 9 dogs were still receiving fluconazole and 8 of 9 dogs had positive results for serum IgG titer testing. CLINICAL RELEVANCE Dogs with COM typically had a rapid improvement in clinical signs after initiating treatment with fluconazole but required long-term antifungal treatment. Dogs with COM differed from dogs with OSA, but radiographic features had a great degree of overlap between groups, confounding the ability to make a diagnosis on the basis of diagnostic imaging alone.

scholarly journals Does Lidocaine Cause False Positive Results on Cocaine Urine Drug Screen?

2019 ◽  
Vol 15 (4) ◽  
pp. 255-261 ◽  
Author(s):  
Eungjae Kim ◽  
Brian Patrick Murray ◽  
Maryam Salehi ◽  
Tim P. Moran ◽  
Joseph E. Carpenter ◽  
...  
Keyword(s):  
False Positive ◽  
Drug Screen ◽  
Urine Drug Screen ◽  
Urine Drug ◽  
Positive Results
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