Diagnostic Performance of Ankle-Brachial Pressure Index in Lower Extremity Arterial Disease

Abstract Introduction Ankle-brachial pressure indices (ABIs) continue to form the basis of diagnostics for lower extremity arterial disease (LEAD). However, there remains a paucity of data to support its accuracy. This study aims to evaluate its diagnostic sensitivity and specificity using established arterial-imaging modalities as a benchmark. Methods In this retrospective study, a regional, prospectively maintained, vascular laboratory database was interrogated to identify referred patients with arterial disease who underwent concomitant assessment with ABI and lower limb arterial duplex ultrasound (DUS). Duplex acted as the reference standard. Those who had peripheral computed tomography angiogram (CTA) within 3 months of initial assessment were included in a subgroup analysis to correlate ABI with CTA. The primary end point was the sensitivity and specificity of ABI compared with DUS as the reference standard. Results Concomitant assessment was performed in 438 limbs (250 patients) over a 27-month period. The ABI was normal (0.9 to 1.4) in 196 limbs (44.9%) and abnormal in the remaining 241 limbs (55.1%). False-positive results occurred in 83 out of 241 limbs (34.4%), and false-negative results occurred in 54 limbs out of 196 (27.5%). True-positive results were 158 out of 241 limbs (65.6%), whereas true-negative results were 142 out of 196 limbs (72.4%). ABI using DUS as a benchmark identified a sensitivity for peripheral artery disease of 72.3% and a specificity of 69.3%. Concomitant CTA imaging was available in 200 limbs. The sensitivity and specificity of ABI correlated with CTA were 65.5 and 68.8%, respectively. Conclusion ABIs have a moderate predictive value in the diagnosis of LEAD. Normal range outcomes cannot be taken to infer the absence of LEAD and, as such, further arterial imaging in the form of DUS or angiography should be strongly considered in those with suspected underlying disease requiring intervention. Further noninvasive tests such as exercise studies or pulse volume waveforms should be considered, if diagnostic uncertainty exists, in those requiring nonoperative intervention and risk factor control.

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Droplet Digital PCR – A Superior Complementary Technique for SARS-CoV-2 Detection

Asian Journal of Biology ◽

10.9734/ajob/2020/v9i430092 ◽

2020 ◽

pp. 12-15

Author(s):

I. M. Hussaini ◽

S. Gide ◽

B. Musa ◽

M. A. Sulaiman ◽

A. Usman

Keyword(s):

Sensitivity And Specificity ◽

False Negative ◽

Standard Technique ◽

Digital Pcr ◽

Droplet Digital Pcr ◽

Reference Standard ◽

Rt Pcr ◽

Negative Results ◽

False Negative Results ◽

Current Reference Standard

Accurate and timely SARS-CoV-2 detection in suspected persons is crucial in the fight against its spread. Many techniques have been developed to meet up with the continuously growing demand, however some of these techniques lack the required accuracy, sensitivity and specificity. The current reference standard technique for SARS-CoV-2 detection is RT-PCR, but studies have shown that false-negative results are inevitable and data can be non-reproducible when samples and primers are not appropriately verified and validated. Droplet digital PCR (ddPCR) is a newly introduced technique that performs precise nucleic acid quantification. Researchers have evaluated the efficacy of ddPCR and the technique has shown promising results even in specimens with low viral load. ddPCR has shown increased accuracy, precision, sensitivity and specificity. Furthermore, it is less affected by annealing and amplification inhibitors. This suggests that ddPCR can be used as a complementary detection technique especially in convalescent cases.

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Evaluation of Serum Cryptococcal Antigen Testing Using Two Novel Semiquantitative Lateral Flow Assays in Persons with Cryptococcal Antigenemia

Journal of Clinical Microbiology ◽

10.1128/jcm.02046-19 ◽

2020 ◽

Vol 58 (4) ◽

Cited By ~ 1

Author(s):

Caleb Skipper ◽

Kiiza Tadeo ◽

Emily Martyn ◽

Elizabeth Nalintya ◽

Radha Rajasingham ◽

...

Keyword(s):

False Positive ◽

Diagnostic Performance ◽

False Negative ◽

Lateral Flow ◽

Reference Standard ◽

Serum Samples ◽

Cryptococcal Antigen ◽

Negative Results ◽

Lateral Flow Assays ◽

Positive Results

ABSTRACT Early cryptococcal disease can be detected via circulating antigen in blood before fulminant meningitis develops, when early antifungal therapy improves survival. Two semiquantitative cryptococcal antigen (CrAg) lateral flow assays (LFAs) have been developed, but their diagnostic performance has not been defined. Cryopreserved serum samples from HIV-infected Ugandans obtained as part of a prospective CrAg-screening cohort were tested in duplicate for CrAg by the CrAgSQ (IMMY) and CryptoPS (Biosynex) lateral flow assays. Case-controlled diagnostic performance was measured using the FDA-approved CrAg LFA (IMMY) as a reference standard via McNemar’s test. Of 99 serum samples tested, 57 were CrAg positive (CrAg+) by the CrAg LFA reference standard. By CrAgSQ, 57 were read as positive, with 98% sensitivity (56/57; 95% confidence interval [CI], 0.91 to 0.99) and 98% specificity (41/42; 95% CI, 0.88 to 0.99) (McNemar’s, P = 0.99). The sample with a false-negative result by CrAgSQ (n = 1) had a titer of <1:5, while the sample with a false-positive result (n = 1) yielded a 1+ result. By CryptoPS, 52 samples were read as positive, with 88% sensitivity (50/57; 95% CI, 0.76 to 0.95) and 95% specificity (40/42; 95% CI, 0.84 to 0.99) (McNemar’s, P = 0.18). The CryptoPS false-negative results included samples with titers of <1:5 (n = 1), 1:5 (n = 5), and 1:20 (n = 1), while samples with false-positive results by CryptoPS (n = 2) yielded Positive results. The CryptoPS assay missed 35% (7/20) of samples with CrAg LFA titers of ≤1:20. The new semiquantitative CrAg LFAs allow rapid estimation of titer levels in easy-to-perform platforms. The CrAgSQ demonstrated better qualitative sensitivity and specificity than the CryptoPS compared to the reference standard. The exact grading of the CrAgSQ results has some subjectivity, with interreader variability; however, qualitative reads were generally concordant for both assays.

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Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649161 ◽

1974 ◽

Vol 31 (02) ◽

pp. 273-278

Author(s):

Kenneth K Wu ◽

John C Hoak ◽

Robert W Barnes ◽

Stuart L Frankel

Keyword(s):

Deep Vein Thrombosis ◽

False Positive ◽

False Negative ◽

Critical Evaluation ◽

Original Method ◽

Vein Thrombosis ◽

Negative Results ◽

False Negative Results ◽

Deep Vein ◽

Positive Results

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.

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Retraction Note: Association of severity of coronary artery disease by SYNTAX score (SS) and lower extremity arterial disease by duplex ultrasound (DUS) study—an Indian perspective

The Egyptian Heart Journal ◽

10.1186/s43044-020-00130-9 ◽

2020 ◽

Vol 72 (1) ◽

Author(s):

Saumen Nandi ◽

Anindya Mukherjee ◽

Dibbendhu Khanra ◽

Kaushik Biswas

Keyword(s):

Coronary Artery Disease ◽

Coronary Artery ◽

Lower Extremity ◽

Duplex Ultrasound ◽

Arterial Disease ◽

Syntax Score ◽

Lower Extremity Arterial Disease ◽

Retraction Notice ◽

Artery Disease ◽

Indian Perspective

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1186/s43044-020-00091-z.

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Omega-3 Polyunsaturated Fatty Acid Supplementation in Patients with Lower Extremity Arterial Disease

Journal of the American College of Nutrition ◽

10.1080/07315724.2021.1891155 ◽

2021 ◽

pp. 1-9

Author(s):

Min-I Su ◽

Ying-Chih Cheng ◽

Yu-Chen Huang ◽

Cheng-Wei Liu

Keyword(s):

Fatty Acid ◽

Lower Extremity ◽

Polyunsaturated Fatty Acid ◽

Arterial Disease ◽

Omega 3 ◽

Lower Extremity Arterial Disease ◽

Fatty Acid Supplementation ◽

Acid Supplementation

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Are predictors of coronary heart disease and lower-extremity arterial disease in type 1 diabetes the same?

Atherosclerosis ◽

10.1016/s0021-9150(99)00217-8 ◽

2000 ◽

Vol 148 (1) ◽

pp. 159-169 ◽

Cited By ~ 99

Author(s):

Kimberly Y.-Z Forrest ◽

Dorothy J Becker ◽

Lewis H Kuller ◽

Sidney K Wolfson ◽

Trevor J Orchard

Keyword(s):

Coronary Heart Disease ◽

Type 1 Diabetes ◽

Heart Disease ◽

Lower Extremity ◽

Arterial Disease ◽

Lower Extremity Arterial Disease

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Evaluation of Recombinant Proteins of Burkholderia mallei for Serodiagnosis of Glanders

Clinical and Vaccine Immunology ◽

10.1128/cvi.00137-12 ◽

2012 ◽

Vol 19 (8) ◽

pp. 1193-1198 ◽

Cited By ~ 11

Author(s):

Vijai Pal ◽

Subodh Kumar ◽

Praveen Malik ◽

Ganga Prasad Rai

Keyword(s):

Sensitivity And Specificity ◽

Recombinant Proteins ◽

False Negative ◽

Enzyme Linked Immunosorbent Assay ◽

Burkholderia Mallei ◽

Content Type ◽

Whole Cells ◽

Negative Results ◽

Elisa Format ◽

Low Sensitivity

ABSTRACTGlanders is a contagious disease caused by the Gram-negative bacillusBurkholderia mallei. The number of equine glanders outbreaks has increased steadily during the last decade. The disease must be reported to the Office International des Epizooties, Paris, France. Glanders serodiagnosis is hampered by the considerable number of false positives and negatives of the internationally prescribed tests. The major problem leading to the low sensitivity and specificity of the complement fixation test (CFT) and enzyme-linked immunosorbent assay (ELISA) has been linked to the test antigens currently used, i.e., crude preparations of whole cells. False-positive results obtained from other diagnostic tests utilizing crude antigens lead to financial losses to animal owners, and false-negative results can turn a risk into a possible threat. In this study, we report on the identification of diagnostic targets using bioinformatics tools for serodiagnosis of glanders. The identified gene sequences were cloned and expressed as recombinant proteins. The purified recombinant proteins ofB. malleiwere used in an indirect ELISA format for serodiagnosis of glanders. Two recombinant proteins, 0375H and 0375TH, exhibited 100% sensitivity and specificity for glanders diagnosis. The proteins also did not cross-react with sera from patients with the closely related disease melioidosis. The results of this investigation highlight the potential of recombinant 0375H and 0375TH proteins in specific and sensitive diagnosis of glanders.

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