Unequal Concentrations of Free T3 and Free T4 after Ultrafiltration

Fritz, Kristofer S.; Weiss, Rene M.; Nelson, Jerald C.; Wilcox, R. Bruce

doi:10.1373/clinchem.2007.087395

Cited by 6 publications

(2 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The choice of ultrafiltration device appears to influence the measured free TH concentration and several devices were reported to leak TH-binding proteins across the filter, resulting in erroneously high free TH concentrations. [56][57][58] An ultrafiltration device that has been employed by several authors (Table 1) to obtain free THs is the Centrifree Ultrafiltration Device (30 kDa MWCO, Millipore), a disposable centrifugal filter. 51,[59][60][61][62] Tanoue et al 58 compared this device to two other 30 kDa MWCO ultrafiltration devices (Amicon Ultra and Nanosep Omega) for the measurement of free TH in bovine serum and concluded that Centrifree had superior performance in their setup.…”

Section: Free Hormones Obtained By Ultrafiltration: Possible But Not ...mentioning

confidence: 99%

“…The choice of ultrafiltration device appears to influence the measured free TH concentration and several devices were reported to leak TH‐binding proteins across the filter, resulting in erroneously high free TH concentrations. 56 , 57 , 58 An ultrafiltration device that has been employed by several authors (Table 1 ) to obtain free THs is the Centrifree Ultrafiltration Device (30 kDa MWCO, Millipore), a disposable centrifugal filter. 51 , 59 , 60 , 61 , 62 Tanoue et al.…”

Section: Measuring Free Ths Using Lc‐ms/msmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of free, unbound thyroid hormones by liquid chromatography‐tandem mass spectrometry: A mini‐review of the medical rationale and analytical methods

Westbye,

Aas,

Kelp

et al. 2023

Analytical Science Advances

View full text Add to dashboard Cite

Measurement of hormones is important for the diagnosis and management of endocrine diseases. The thyroid hormones thyroxine (T4) and triiodothyronine (T3) are among the most commonly measured hormones in clinical laboratories, and it is the concentration of free (not bound to proteins) thyroid hormones that is clinically most relevant. Free thyroid hormones are commonly measured using automated immunoassays, however, these are known to produce erroneous results due to interferences for some patients. Measurement of free thyroid hormones using equilibrium dialysis or ultrafiltration combined with liquid chromatography coupled to tandem mass spectrometry (LC‐MS/MS) is considered a more accurate and robust method for free thyroid hormone analysis and overcomes many of the limitations of immunoassays. However, LC‐MS/MS‐based methods are often considered too technically difficult and not amendable to high throughput by clinical chemists and are not offered by many clinical laboratories. This mini‐review aims to make it easier for clinical laboratories to implement LC‐MS/MS‐based measurement of free thyroid hormones. It describes the medical rationale for measuring free thyroid hormones, the benefits of LC‐MS/MS‐based methods with respect to interferences affecting immunoassay‐based methods and physical separation methods. This mini‐review highlights important parameters for ultrafiltration and equilibrium dialysis to obtain physiologically relevant free thyroid hormone concentrations and focuses on methods and devices used in clinical chemistry.

show abstract