Determination of free thyroid hormones and their binding proteins in a patient with severe hyperthyroidism (thyroid storm?) and thyroid encephalopathy

1984 ◽  
Vol 7 (4) ◽  
pp. 379-381 ◽  
Author(s):  
R. Colebunders ◽  
P. Bourdoux ◽  
J. Bekaert ◽  
C. Mahler ◽  
G. Parizel
Keyword(s):  
Thyroid Hormones ◽  
Binding Proteins ◽  
Thyroid Storm ◽  
Free Thyroid Hormones

scholarly journals Performance evaluation of the Vitros®3600 immunodiagnostic system for the determination of free thyroid hormones

2011 ◽  
Vol 49 (8) ◽  
Author(s):  
Giorgia Querci ◽  
Giulia Galli ◽  
Paolo Piaggi ◽  
Veronica Rosellini ◽  
Monica Giannetti ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Thyroid Hormones ◽  
Free Thyroid Hormones

Serum free thyroid hormones in different degrees of hypothyroidism and in euthyroid autoimmune thyroiditis

1987 ◽  
Vol 114 (4) ◽  
pp. 559-564 ◽  
Author(s):  
C. Ferrari ◽  
A. Paracchi ◽  
E. Parisio ◽  
F. Codecasa ◽  
M. Mucci ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Thyroid Function ◽  
Autoimmune Thyroiditis ◽  
Subclinical Hypothyroidism ◽  
Healthy Subjects ◽  
Direct Determination ◽  
Serum Free ◽  
Free Thyroid Hormones ◽  
Hypothyroid Patients

Abstract. Serum total and free T4 and T3, thyroxinebinding globulin (TBG) and TSH, basal and 20, 30 and 60 min after TRH (200 μg, iv), were evaluated in 125 hypothyroid patients (38 with severe, 23 with mild, and 64 with subclinical hypothyroidism), in 35 euthyroid subjects with autoimmune thyroiditis, and in 51 healthy controls. T4/TBG and T3/TBG ratios were also calculated. A significant decrease in all indices of thyroid function except for T3 occurred simultaneously with a significant increase in basal and TRH-stimulated TSH levels from healthy subjects to subclinical hypothyroids, from subclinical to mild and from mild to severe hypothyroids; euthyroid patients with autoimmune thyroiditis did not differ from healthy subjects. All severe hypothyroid patients had low T4 as well as free T4 (FT4), free T3 (FT3), T4/TBG and T3/TBG ratios, but among mild and subclinical hypothyroids direct determination of FT4 and FT3 proved to be a better index of thyroid function than determination of T4 and T3 even after correction for TBG levels. FT4 was the most commonly abnormal index (19 of 23 subjects with mild and 14 of 64 with subclinical disease). Regression analysis showed that FT4, T4/TBG ratio, T4, and FT3 had a significant inverse correlation with TSH in hypothyroid patients. Discriminant analysis showed that among the thyroid parameters, FT4 is the variable which discriminates best between control subjects and the 3 groups of hypothyroid patients. These data extend previous reports and in a large series of patients confirm the biological meaning and the clinical value of direct measurement of serum free thyroid hormones in hypothyroidism. Nevertheless, the finding that both FT4 and FT3 are in the normal range in some patients with mild and in most with subclinical hypothyroidism indicates that increased TSH secretion remains the most sensitive index of thyroid failure.

Determination of free thyroid hormones

2013 ◽  
Vol 27 (5) ◽  
pp. 689-700 ◽  
Author(s):  
Linda M. Thienpont ◽  
Katleen Van Uytfanghe ◽  
Kris Poppe ◽  
Brigitte Velkeniers
Keyword(s):  
Thyroid Hormones ◽  
Free Thyroid Hormones

The influence of free fatty acids on the free fraction of thyroid hormones in serum as estimated by ultrafiltration

1987 ◽  
Vol 116 (1) ◽  
pp. 102-107 ◽  
Author(s):  
C. Bregengåard ◽  
C. Kirkegaard ◽  
J. Faber ◽  
S. Poulsen ◽  
K. Siersbæk-Nielsen ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Thyroid Hormones ◽  
Healthy Subjects ◽  
Binding Proteins ◽  
Free Fraction ◽  
Nonthyroidal Illness ◽  
Serum Free ◽  
Free Thyroid Hormones ◽  
Serum Pool ◽  
Somatic Illness

Abstract. Thyroid hormones are displaced from their binding proteins in serum during nonthyroidal somatic illness, and FFA have been claimed to contribute. It seems mandatory to evaluate this effect using techniques for the measurements of serum free thyroid hormones in which serum remains undiluted. We measured the effect of 7 common human FFA on the free fraction of T4, T3 and rT3 in serum from healthy subjects using an ultrafiltration technique by which serum is diluted only minimally. In addition we measured the effect of oleic acid on the free fractions of the iodothyronines in pooled serum from healthy subjects and in pooled serum from patients with nonthyroidal illness. All FFA tested were able to displace both T4, T3 and rT3, but to a varying degree, arachidonic and linoleic acid being the most potent ones. A 20% increase in the free fractions of T4, T3 and rT3, respectively, was obtained by adding between 1.7–3.3 mmol/l, 1.3–4.6 mmol/l and 1.0–2.4 mmol/l of the different FFA. A serum pool obtained from patients with nonthyroidal somatic illness was more sensitive to oleic acid than a serum pool obtained from healthy subjects, since 2–3 times less oleic acid was necessary to induce a 20% increase in the free fractions of thyroid hormones. It is concluded that FFA are able to displace both T4, T3 and rT3 from their serum binding proteins in healthy subjects as well as in patients with nonthyroidal illness. However, serum from patients with nonthyroidal illness was more sensitive to the displacing activity of oleic acid than serum from healthy subjects. This was possibly due to reduced affinity of the serum binding proteins to thyroid hormones, and it could be argued that a factor different from FFA seemed responsible.

scholarly journals The effect of specific binding proteins on immunoassay measurements of total and free thyroid hormones and cortisol

2021 ◽  
Vol 12 ◽  
pp. 204201882198924
Author(s):  
Anastasia Gant Kanegusuku ◽  
Katherine A. Araque ◽  
Hung Nguyen ◽  
Bin Wei ◽  
Saman Hosseini ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Binding Proteins ◽  
Specific Binding ◽  
Free Triiodothyronine ◽  
Free Thyroid Hormones ◽  
Signed Rank ◽  
The Us ◽  
Liquid Chromatography Tandem Mass ◽  
Low Levels ◽  
The Difference

Background: Immunoassay (IA) measurements of thyroid hormones have previously given inaccurate results of triiodothyronine (T3), free triiodothyronine (FT3), and free thyroxine (FT4) when concentrations of TBG are low. We evaluate the hypothesis that abnormal concentrations of specific binding proteins (BPs) affect IA measurements and provide results which might misguide the diagnosis and treatment of patients. This study assesses IAs for the measurement of T3, FT3, and cortisol when levels of TBG and CBG are high or low. Comparisons are made between IA and LC-MS/MS. Methods: Serum or plasma samples with high (>95th percentile, n = 25) or low (<5th percentile, n = 27) concentrations of BP were collected. The concentrations of T3, FT3, and cortisol were measured by validated IA and liquid chromatography tandem mass spectrometry (LC-MS/MS) methods. Spearman correlation and Wilcoxon matched-pairs signed rank analyses were used to compare the two methods. Results: When TBG levels are <5th percentile, the differences between the IA and LC-MS/MS results for T3 and FT3 are statistically significant (T3, p = 0.0011; FT3, p = 0.0003). When CBG levels are >95th percentile, the difference between the IA and LC-MS/MS measurements of cortisol is statistically significant ( p = <0.0001). Conclusion: Abnormal BP concentrations appear to affect the accuracy of IA measurements of T3, FT3, and cortisol. The population of patients with either high or low levels of BPs is significant. Our samples reflect that 65% of women aged between 15 and 49 years are taking oral contraceptives in the US, and thus have elevated levels of BPs. In this group, IA results for cortisol are falsely low. Our samples reflect that patients with protein losing diseases have low BP concentrations. Among a group with renal complications, IA measurements of T3 are overestimated, while those of FT3 are underestimated. Are the Food and Drug Administration and diagnostic companies adequately assessing the accuracy of IA tests?

Transient Prealbumin- Associated Hyperthyroxinemia in TSH-Producing Pituitary Adenoma

1990 ◽  
Vol 29 (01) ◽  
pp. 40-43 ◽  
Author(s):  
W. Langsteger ◽  
P. Költringer ◽  
P. Wakonig ◽  
B. Eber ◽  
M. Mokry ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Case Report ◽  
Pituitary Adenoma ◽  
Thyroid Hormones ◽  
Protein Binding ◽  
Alpha Subunit ◽  
Normal Range ◽  
Thyroxine Binding Globulin ◽  
Free Thyroid Hormones ◽  
Transmission Computed Tomography

This case report describes a 38-year-old male who was hospitalized for further clarification of clinically mild hyperthyroidism. His increased total hormone levels, the elevated free thyroid hormones and the elevated basal TSH with blunted response to TRH strongly suggested a pituitary adenoma with inappropriate TSH incretion. Transmission computed tomography showed an intrasellar expansion, 16 mm in diameter. The neoplastic TSH production was confirmed by an elevated alpha-subunit and a raised molar alpha-sub/ATSH ratio. However, T4 distribution on prealbumin (PA, TTR), albumin (A) and thyroxine binding globulin (TBG) showed a clearly increased binding to PA (39%), indicating additional prealbumin-associated hyperthyroxinemia. The absolute values of PA, A and TBG were within the normal range. After removal of the TSH-producing adenoma, basal TSH, the free thyroid hormones and T4 binding to prealbumin returned to normal. Therefore, the prealbumin-associated hyperthyroxinemia had to be interpreted as a transitory phenomenon related to secondary hyperthyroidism (T4 shift from thyroxine binding globulin to prealbumin) rather than a genetically conditioned anomaly of protein binding.

MEASUREMENT OF STEROID BINDING PROTEINS

1970 ◽  
Vol 65 (1_Suppl) ◽  
pp. S104-S121 ◽  
Author(s):  
E. E. Baulieu ◽  
J. P. Raynaud ◽  
E. Milgrom
Keyword(s):  
Kinetic Parameters ◽  
Binding Proteins ◽  
Binding Specificity ◽  
Binding Parameters ◽  
Target Organs ◽  
Biological Mixtures ◽  
Steroid Binding Proteins ◽  
Steroid Binding ◽  
Steroid Binding Protein

ABSTRACT A brief review of the characteristics of steroid binding proteins found in the plasma and in some target organs is presented, followed by some general remarks on binding »specificity« and binding parameters. Useful techniques for measuring binding parameters at equilibrium are reported, both those which keep the equilibrium intact and those which implicate its disruption. A concept is developed according to which the determination of a specific steroid binding protein is based on the »differential dissociation« of the several steroid binding complexes present in most biological mixtures. Methods which allow determination of the kinetic parameters of the binding systems are also presented. Various representations of the binding and therefore different modes of graphic representation and calculation are discussed, including the recent »proportion graph« method.

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