scholarly journals Two Cases of Armour Thyroid Interference in Thyroglobulin Monitoring for Thyroid Cancer

2021 ◽  
Vol 2021 ◽  
pp. 1-4
Author(s):  
Michelle Ponder ◽  
Elizabeth Lamos ◽  
Kashif Munir
Keyword(s):  
Thyroid Cancer ◽  
Differentiated Thyroid Cancer ◽  
High Sensitivity ◽  
Thyroid Extract ◽  
Chromatography Tandem Mass Spectrometry ◽  
Thyroglobulin Antibody ◽  
Liquid Chromatography Tandem Mass ◽  
History Of ◽  
Made In

Thyroglobulin (Tg) monitoring is the biochemical standard for surveillance of recurrent differentiated thyroid cancer (DTC). Several assays are available to quantify Tg levels: immunometric assay (IMA), radioimmunoassay (RIA), and the newer liquid chromatography tandem mass spectrometry (LC-MS). It is well known that a number of entities can interfere with the accuracy of testing, and at this point in time, no one assay perfectly balances high sensitivity with low risk of interference. In this case study, we present two cases in which treatment with desiccated thyroid extract (Armour thyroid) led to a sudden elevation in Tg, which resolved when Armour thyroid was discontinued. This elevation occurred when Tg was measured with both IMA and LC-MS, which suggests direct interference from porcine Tg rather than heterophilic or thyroglobulin antibody (TgAb) interference. We suggest that patients with a history of DTC not be treated with desiccated thyroid extracts consistent with guidelines. Furthermore, more advances need to be made in the area of Tg testing to improve specificity and avoid detection of nonhuman Tg and other similar proteins.

scholarly journals Utility of recombinant human TSH stimulation test in the follow-up of patients with differentiated thyroid cancer depending on basal thyroglobulin results

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Amaia Sandúa ◽  
Monica Macias ◽  
Carolina Perdomo ◽  
Juan Carlos Galofre ◽  
Roser Ferrer ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Differentiated Thyroid Cancer ◽  
Characteristic Curve ◽  
Area Under The Curve ◽  
High Sensitivity ◽  
Thyroid Stimulating Hormone ◽  
Stimulation Test ◽  
Human Thyroid ◽  
Antithyroglobulin Antibodies ◽  
Structural Disease

AbstractBackgroundThyroglobulin (Tg) is fundamental for differentiated thyroid cancer (DTC) monitoring. Tg detection can be enhanced using recombinant human thyroid-stimulating hormone (TSH) (rhTSH). This study is aimed to evaluate the use of the rhTSH stimulation test when using a high-sensitivity Tg assay.MethodsWe retrospectively studied 181 rhTSH tests from 114 patients with DTC and negative for antithyroglobulin antibodies (anti-TgAb). Image studies were performed in all cases. Serum Tg and anti-TgAb were measured using specific immunoassays.ResultsrhTSH stimulation in patients with basal serum Tg (b-Tg) concentrations lower than 0.2 ng/mL always resulted in rhTSH-stimulated serum Tg (s-Tg) concentrations lower than 1.0 ng/mL and negative structural disease. In patients with b-Tg concentration between 0.2 and 1.0 ng/mL, s-Tg detected one patient (1/30) who showed biochemical incomplete response. Patients with negative images had lower s-Tg than those with nonspecific or abnormal findings (p<0.05). Receiver operating characteristic curve analysis of the s-Tg to detect altered images showed an area under the curve of 0.763 (p<0.05). With an s-Tg cutoff of 0.85 ng/mL, the sensitivity was 100%, decreasing to 96.15% with an s-Tg cutoff of 2 ng/mL.ConclusionsPatients with DTC with b-Tg concentrations equal or higher than 0.2 ng/mL can benefit from the rhTSH stimulation test.

scholarly journals Quantitation of Benzodiazepines and Metabolites in Urine by Liquid Chromatography–Tandem Mass Spectrometry

2018 ◽  
Vol 3 (3) ◽  
pp. 397-407
Author(s):  
Yu Zi Zheng ◽  
Dustin R Bunch ◽  
Katherine Lembright ◽  
Sihe Wang
Keyword(s):  
Precise Measurement ◽  
High Sensitivity ◽  
Urine Samples ◽  
Limit Of Quantification ◽  
Internal Standards ◽  
Independent Laboratory ◽  
Chromatography Tandem Mass Spectrometry ◽  
Analytical Recovery ◽  
Liquid Chromatography Tandem Mass ◽  
Analytical Time

Abstract Background Benzodiazepines (BZDs) are central nervous system depressants that are prescribed to prevent seizures, manage anxiety, or help sleep. When misused, BZDs can lead to addiction and sometimes cause death. Measurement of BZDs in urine is used to identify their use, especially in pain management settings. LC-MS/MS is preferred for these measurements because of its high sensitivity and specificity. Here, we report an LC-MS/MS assay for measuring 7 BZDs and metabolites in urine. Methods Urine sample was incubated at 60 °C for 30 min after addition of internal standards and a β-glucuronidase solution. After centrifugation, the supernatant was diluted with methanol and water before being injected onto a C18 analytical column in an LC-MS/MS system for quantification. The analytical time between injections was 4.35 min. The analytes included 7-aminoclonazepam, α-hydroxyalprazolam, α-hydroxytriazolam, oxazepam, lorazepam, nordiazepam, and temazepam. Results The lower limit of quantification ranged from 30 ng/mL to 50 ng/mL with an analytical recovery &gt;80% for all 7 analytes. Total CV was &lt;10% for all analytes (3 concentration levels of 100, 2500, and 5000 ng/mL; n = 30 each). This method had 100% agreement with a GC-MS method offered by an independent laboratory for negative urine samples. For the positive urine samples, this method showed a strong correlation (R &gt; 0.96) with the GC-MS method. Conclusions The LC-MS/MS assay allows accurate and precise measurement of 7 BZDs and metabolites in a single analytical run with a short analytical run time and broad measuring ranges.

scholarly journals The Torah in Transition: Imitative Aspects from Codex to Database

2014 ◽  
Vol 3 (3) ◽  
pp. 107-128
Author(s):  
Emily R. Stewart
Keyword(s):  
Jewish Community ◽  
New Technology ◽  
History Of The Book ◽  
Concerted Effort ◽  
The People ◽  
Reading Technology ◽  
History Of ◽  
Digital Formats ◽  
Made In

Because the significance of a sacred text comes not only from its content but also its format and materiality, the rise of digital formats is especially a concern for the Jewish community, the ‘people of the book’ (Am ha-Sefer) whose identity is rooted in the Torah. Drawing together scholarship on the history of the book in its changing formats and an illuminative case study of the Jewish Torah in its digital iterations, the Jewish case presented here is instructive but certainly not unique. Despite dramatic changes in reading technology throughout history, readers have time and again used a new technology to perform the same functions as that of the old, only more quickly, with more efficiency, or in greater quantity. While taking advantage of the innovation and novelty which characterize digital formats, a concerted effort to retain much older operations and appearances continues to be made in this transition as well. The analysis in this article aims to further dispel the misguided notion of technological supersession, the idea that new reading technologies ‘kill’ older formats in a straightforward model of elimination.

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