Quantification of Serum 1–84 Parathyroid Hormone in Patients with Hyperparathyroidism by Immunocapture In Situ Digestion Liquid Chromatography–Tandem Mass Spectrometry

Kumar, Vivek; Barnidge, David R.; Chen, Chien-Jen; Twentyman, Jolaine M.; Cradic, Kendall W.; Grebe, Stefan K.; Singh, Ravinder J.

doi:10.1373/clinchem.2009.134643

Cited by 92 publications

(56 citation statements)

References 23 publications

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“…Both groups used the quantification of the 1-13 amino acid tryptic peptide (SVSEIQLMHNLGK) as a surrogate for the measurement of PTH1-84. Both methods demonstrated good analytical performance, linearity and appropriate limits of quantitation (39.1 [44] and 16 pg/mL [49], respectively, from 1 mL sample). Kumar et al also tested their assay for the 1-13 tryptic peptide for interference from other PTH fragments (PTH1-44, PTH7-84, PTH43-68, PTH52-84 and PTH64-84), PTHrP, and in haemolysed, lipaemic, and icteric samples.…”

Section: -84mentioning

confidence: 95%

“…For some small peptides, techniques traditionally used for small molecule analysis such as solid-phase extraction (SPE) may be useful, and have been successfully applied in a number of clinical assays, e.g., hepcidin [42] and insulin [43]. For larger proteins, or for those requiring more extensive analyte enrichment to allow detection at physiological concentrations, e.g., PTH [44], immunoaffinity extraction (sometimes referred to as immunocapture or immunoextraction) is a novel approach which is increasingly being used [45][46][47][48].…”

Section: Mass Spectrometrymentioning

confidence: 99%

“…Recently, two groups have published quantitative LC-MS/ MS methods for the analysis of PTH1-84 in clinical samples [44,49]. With these methods now available, it has been recognised that the development of a candidate reference method for PTH is now a possibility [16].…”

Section: Quantitative Lc-ms/ms Pth Assaysmentioning

confidence: 99%

“…With these methods now available, it has been recognised that the development of a candidate reference method for PTH is now a possibility [16]. Both methods utilise immunoaffinity extraction with a C-terminal anti-PTH capture antibody, either immobilised onto polystyrene beads [44] or onto customised MSIA pipette tips [49]. In both methods, following washing steps to remove nonspecific binding, the captured PTH1-84 and related fragments are digested using trypsin.…”

Section: Quantitative Lc-ms/ms Pth Assaysmentioning

confidence: 99%

“…Kumar et al [44] used isotopically labelled ( 15 N) PTH1-84 as the internal reference standard, whereas Lopez et al [49] used individual isotopically labelled tryptic peptides (one for each tryptic peptide monitored). Both groups used the quantification of the 1-13 amino acid tryptic peptide (SVSEIQLMHNLGK) as a surrogate for the measurement of PTH1-84.…”

Section: -84mentioning

confidence: 99%

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LC-MS candidate reference methods for the harmonisation of parathyroid hormone (PTH) measurement: a review of recent developments and future considerations

Couchman¹,

Taylor

Krastins

et al. 2014

Clinical Chemistry and Laboratory Medicine

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Abstract:The analysis of intact parathyroid hormone (PTH) (PTH1-84) is useful in the diagnosis of hyper-and hypocalcaemia, hyperparathyroidism, and in the prevention of bone mineral disorders in renal patients. The analysis is complicated by the presence of PTH fragments, which may accumulate in renal failure and cross-react in immunoassays, including the most recent third-generation immunoassays. Large variability exists between different commercially available assays. This article reviews the current literature on PTH testing, with emphasis on the use of mass spectrometry-based methods, and considers the important sources of variation which still need to be addressed prior to the development of much needed candidate reference methods for PTH analysis. Recently, mass spectrometric methods have been developed for the quantitation of PTH1-84 using surrogate tryptic peptides, but even these methods are subject to significant interferences due to the presence of newly observed modified PTH species, such as oxidised and phosphorylated PTH variants, which can accumulate in patient samples. Further work, including: 1) the use of high-resolution mass spectrometry; and 2) the analysis of PTH without prior protease digestion, is required before these approaches can be considered as reference methods against which other methods should be harmonised.

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Section: -84mentioning

confidence: 95%