Laboratory medicine practice guidelines: laboratory support for the diagnosis and monitoring of thyroid disease

Demers, Laurence M.; Spencer, Carole A.

doi:10.1046/j.1365-2265.2003.01681.x

Cited by 297 publications

(295 citation statements)

References 2 publications

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“…Reviews of laboratory tests currently used in the diagnosis of thyroid disease have recently been published [1,2]. The two preferred laboratory tests to assess thyroid function today are free T4 and TSH.…”

Section: Introductionmentioning

confidence: 99%

The measurement of free thyroxine by isotope dilution tandem mass spectrometry

Soldin¹,

Soukhova²,

Janicic³

et al. 2005

Clinica Chimica Acta

109

119

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Background-Most clinical chemistry laboratories measure free thyroxine (FT4) by an analogue (direct) method. Nevertheless, the validity of analogue FT4 immunoassays has been questioned and patient's results using this approach frequently do not fit in with the clinical presentation. Because of these problems we routinely send out all direct free T4's that are < 2.5th percentile and many that are > 97.5th percentile for measurement by equilibrium dialysis, the gold standard method. In approximately half of these cases, the FT4 by equilibrium dialysis was normal. We developed a rapid, reliable free T4 method employing isotope dilution tandem mass spectrometry and compared our results with both the analogue (direct) free T4 and equilibrium dialysis procedures.Methods-An API-4000 tandem mass spectrometer (Sciex, Toronto, Canada) equipped with TurboIonSpray and Agilent HPLC system was used employing isotope dilution with deuterium labeled internal standard (IS=L-thyroxine-d 2 ). Serum was filtered through the Centrifree YM-30 ultrafiltration device by centrifugation, IS added to the ultrafiltrate, and 400 μL injected onto a C-18 column. After washing, the switch valve is activated and a methanol gradient allows for elution of both T4 and the IS into the LC/MS/MS system. Quantitation was by MRM analysis in the negative mode. Equilibrium dialysis was performed by the Nichols method and analogue free T4 results were obtained on the Dade Dimension RxL.Results-The within-day and between-day CV's were < 7.1% at all concentrations tested. The results correlated well with equilibrium dialysis (Eq Dial=0.971 MS+0.041, n =68, Syx=1.381, r =0.954). A poor correlation was found with the analogue (direct) free T4 method (IA=0.326 MS +6.27, n =154, Syx=1.96, r =0.459). Conclusions-Samples can be processed in batches of 30. The free T4 tandem MS method has a rapid turn-around-time vs the equilibrium dialysis procedure, with a chromatographic run time of 8 min per sample. NIH Public Access

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Section: Introductionmentioning

confidence: 99%

The measurement of free thyroxine by isotope dilution tandem mass spectrometry

Soldin¹,

Soukhova²,

Janicic³

et al. 2005

Clinica Chimica Acta

109

119

View full text Add to dashboard Cite

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“…While several epidemiologic studies have examined factors related to serum Tg in large population-based settings (Krejbjerg et al, 2016;Ma and Skeaff, 5 2014), only one other study has examined factors related to Tg in a radiation exposed population with mild-to-moderate iodine deficiency (Cahoon et al, 2013). In addition, studies reporting serum Tg concentrations often fail to assess assay interference by serum autoantibodies (Spencer et al, 2011), and may use different measurement assays without proper inter-study assay standardization, complicating both quantification of serum Tg concentration and comparability to other studies (Demers and Spencer, 2002;Spencer et al, 1998).…”

Section: Most Studies Of Serum Tg Have Been Conducted Among Individuamentioning

confidence: 99%

“…Serum Tg concentration was dichotomized to elevated Tg (>40 µg/L; n=920), which is the upper limit from the adult reference range of serum Tg concentration in an iodine replete American population (Demers and Spencer, 2002) to estimate the odds ratio (OR) and 95% confidence interval (CI) of elevated serum Tg for UIC categories and thyroid volume quintiles. We also tested for departure from linearity (on a log scale)…”

mentioning

confidence: 99%

Factors associated with serum thyroglobulin in a Ukrainian cohort exposed to iodine-131 from the accident at the Chernobyl Nuclear Plant

Peters

Тronko

Hatch

et al. 2017

Environmental Research

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Background: Serum thyroglobulin (Tg) is associated with the presence of thyroid disease and has been proposed as a biomarker of iodine status. Few studies have examined factors related to serum Tg in populations environmentally exposed to ionizing radiation and living in regions with endemic mild-tomoderate iodine deficiency. Methods:We screened 10,430 individuals who were living in Ukraine and under 18 years of age at the time of the 1986 Chernobyl Nuclear Power Plant accident for thyroid disease from 2001 to 2003. We estimated the percent change (PC) in serum Tg associated with demographic factors, iodine-131 thyroid dose, and indicators of thyroid structure and function using linear regression. We also examined these relationships for individuals with and without indications of thyroid abnormality.Results: Mean and median serum Tg levels were higher among participants with abnormal thyroid structure/function. Percent change in serum Tg increased among females, smokers and with older age (pvalues < 0.001), and Tg increased with increasing thyroid volume, and serum thyrotropin (p-values for trend < 0.001). We found no evidence of significant associations between iodine-131 thyroid dose and Tg. Serum Tg levels were inversely associated with iodized salt intake (PC= -7.90, 95% confidence interval: -12.08, -3.52), and over the range of urinary iodine concentration, the odds of having elevated serum Tg showed a U-shaped curve with elevated Tg at low and high urinary iodine concentrations. Conclusion:Serum Tg may be a useful indicator of population iodine status and a non-specific biomarker of structural and functional thyroid abnormalities in epidemiological studies.

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“…Any change in Tg levels reflects a change in tumor mass. In partial thyroidectomy or lobectomies circulating concentrations of Tg may reflect secretory capacity of both normal and malignant thyroid tissue [7][8].…”

Section: Introductionmentioning

confidence: 99%

The clinical utility of Lens culinaris agglutinin-reactive thyroglobulin ratio in serum for distinguishing benign from malignant conditions of the thyroid

Shimizu¹,

Nakamura²,

Kobatake³

et al. 2007

Clinica Chimica Acta

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Background: Traditionally, the follow-up of differentiated thyroid carcinoma consists of periodic withdrawal from L-T4-suppressive therapy to allow performance of a highly sensitive serum Tg measurement to detect recurrences. In this study, Lens culinaris agglutinin-reactive thyroglobulin ratios in serum were investigated to evaluate in usefulness for detection of thyroid carcinoma.Methods: The study was conducted on 93 serum sample from 23 healthy volunteers, 32 patients with benign thyroid tumor, 28 patients with thyroid carcinoma without 1 metastasis, and 10 patients with thyroid carcinoma with lymph node metastasis.Results: The Lens culinaris agglutinin-reactive thyroglobulin ratio in patients with thyroid carcinoma was found to be significantly lower than that in patients with benign thyroid tumor in case with serum thyroglobulin concentration > 200 ng/ml.Among cases of thyroid carcinoma with lymph node metastasis, Lens culinari agglutinin-reactive thyroglobulin ratios were significantly lower than in patient with thyroid carcinoma without metastasis and those with benign tumor regardless of serum thyroglobulin concentration.

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Laboratory medicine practice guidelines: laboratory support for the diagnosis and monitoring of thyroid disease

Cited by 297 publications

References 2 publications

The measurement of free thyroxine by isotope dilution tandem mass spectrometry

The measurement of free thyroxine by isotope dilution tandem mass spectrometry

Factors associated with serum thyroglobulin in a Ukrainian cohort exposed to iodine-131 from the accident at the Chernobyl Nuclear Plant

The clinical utility of Lens culinaris agglutinin-reactive thyroglobulin ratio in serum for distinguishing benign from malignant conditions of the thyroid

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