Abstract | BACKGROUND: METHODS: We studied 8 patients with parathyroid carcinoma before and at week 16 of cinacalcet therapy, 6 patients with PHPT, and 6 control individuals. We fractionated sera with HPLC and analyzed fractions with the 2 assays to quantify hPTH(1-84), N-PTH, and non-(1-84) PTH fragments. RESULTS: Half of parathyroid carcinoma patients had an increased wPTH:tPTH ratio [mean (SD), 1.35 (0.29)]; the others had a typical ratio [0.72 (0.12)]. HPLC fractionation of sera from 2 high-ratio patients confirmed N-PTH overproduction [65% (12%) of wPTH]. The N-PTH fraction was <15% of wPTH in PHPT and healthy individuals. Calcimimetic therapy appreciably reduced calcium concentrations in parathyroid carcinoma patients but had little influence on PTH concentration, the wPTH:tPTH ratio, or the PTH HPLC profile. CONCLUSION: N-PTH is overproduced in some parathyroid cancer patients, but calcimimetic therapy does not influence its production. The clinical implications of this finding in parathyroid carcinoma await additional studies with an emphasis on N-PTH's biological activity and with larger numbers of patients.
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Authors | Mishaela R Rubin, Shonni J Silverberg, Pierre D'Amour, Jean-Hugues Brossard, Louise Rousseau, James Sliney Jr, Tom Cantor, John P Bilezikian |
Journal | Clinical chemistry
(Clin Chem)
Vol. 53
Issue 8
Pg. 1470-6
(Aug 2007)
ISSN: 0009-9147 [Print] England |
PMID | 17599957
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
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Chemical References |
- Biomarkers, Tumor
- Naphthalenes
- Parathyroid Hormone
- Peptide Fragments
- amino-terminal parathyroid hormone
- Cinacalcet
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Topics |
- Adult
- Aged
- Biomarkers, Tumor
(biosynthesis)
- Chromatography, High Pressure Liquid
- Cinacalcet
- Female
- Humans
- Hyperparathyroidism, Primary
(drug therapy, metabolism)
- Male
- Middle Aged
- Naphthalenes
(therapeutic use)
- Parathyroid Hormone
(biosynthesis, blood)
- Parathyroid Neoplasms
(drug therapy, metabolism)
- Peptide Fragments
(biosynthesis, blood)
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