Restoration of reversed whole PTH/intact PTH ratio and reduction in parathyroid gland vascularity during cinacalcet therapy for severe hyperparathyroidism in a uraemic patient

OBJECTIVE: It was discovered that an immunoreactive large carboxy-terminal parathyroid hormone (PTH) fragment (large C-PTH), likely 7-84 PTH, is present in the circulation. However, very little is known about the production and metabolism of this large C-PTH. Combining a whole molecule PTH (whole PTH) immunoradiometric assay (IRMA) specifically for 1-84 PTH and an intact PTH (iPTH) IRMA for the sum of 1-84 PTH and large C-PTH, we were able to assess the circulating level of this large C-PTH as well as the glandular secretion and metabolism of this large C-PTH in primary hyperparathyroidism (pHPT). METHODS: This study consisted of two patient groups consisting of 77 pHPT patients with a single adenoma. Of these, 43 comprised the venous sampling study group and 70 comprised the intra-operative PTH study group. (Seven patients belonged only to the former group, 34 patients to only the latter group, and 36 patients to both groups.) Preoperatively, blood samples were drawn from the bilateral internal jugular vein by ultrasonographic guidance and from the peripheral vein (n=43). During surgery, blood samples were drawn after anesthesia (basal level), before excision (pre-excision level) of one enlarged parathyroid gland, and at 5, 10, and 15 min post-excision (n=70). RESULTS: There were 26 patients whose iPTH assay levels differed by more than 10% between the right and left internal jugular. In 24 of the 26 patients, the large C-PTH levels obtained from the adenoma side were significantly higher than those from the contralateral side (117+/-135 vs 43+/-33 pg/ml, P<0.001). The plasma whole PTH values decreased more rapidly than the iPTH values after parathyroidectomy (P<0.001). CONCLUSIONS: Our study has demonstrated that the large C-PTH, likely 7-84 PTH, is directly released from the parathyroid gland in humans. Since the half-life of 1-84 PTH is much shorter than large C-PTH, likely 7-84 PTH, it would be advantageous to use an assay that specifically measures 1-84 PTH for intra-operative monitoring of parathyroidectomy.

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The reversed ratio of 1-84 PTH (whole PTH)/intact PTH in a patient on hemodialysis associated with primary hyperparathyroidism

Clinical Nephrology ◽

10.5414/cnp69310 ◽

2008 ◽

Vol 69 (04) ◽

pp. 310-312 ◽

Cited By ~ 2

Author(s):

Y. Mizumura ◽

Y. Mukaiyama ◽

H. Osada ◽

O. Hida ◽

M. Nishimiya ◽

...

Keyword(s):

Primary Hyperparathyroidism ◽

Intact Pth ◽

Whole Pth

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SUN-272 Changes in whole PTH/intact PTH ratio in patients with chronic kidney disease

Kidney International Reports ◽

10.1016/j.ekir.2019.05.777 ◽

2019 ◽

Vol 4 (7) ◽

pp. S273

Author(s):

K. Okamoto ◽

H. Fujii ◽

S. Goto ◽

K. Watanabe ◽

K. Kono ◽

...

Keyword(s):

Chronic Kidney Disease ◽

Kidney Disease ◽

Intact Pth ◽

Whole Pth

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IRMA (whole PTH) is a more useful assay for the effect of PTH on bone than the Allegro intact PTH assay in CAPD patients with low bone turnover marker

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfg1025 ◽

2003 ◽

Vol 18 (90003) ◽

pp. 97iii-98 ◽

Cited By ~ 2

Author(s):

Y. Tanno

Keyword(s):

Bone Turnover ◽

Bone Turnover Marker ◽

Intact Pth ◽

Low Bone Turnover ◽

Whole Pth

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Decreased expression of calcium-sensing receptor and parafibromin in secondary hyperparathyroidism with an abnormal whole PTH/intact PTH ratio

Clinical Kidney Journal ◽

10.1093/ckj/sft061 ◽

2013 ◽

Vol 6 (4) ◽

pp. 429-432 ◽

Cited By ~ 1

Author(s):

Shunsuke Yamada ◽

Masanori Tokumoto ◽

Masatomo Taniguchi ◽

Hidehisa Kitada ◽

Kazuhiko Tsuruya ◽

...

Keyword(s):

Secondary Hyperparathyroidism ◽

Calcium Sensing Receptor ◽

Intact Pth ◽

Calcium Sensing ◽

Whole Pth

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Comparison of intact PTH assay and whole PTH assay in long-term dialysis patients

American Journal of Kidney Diseases ◽

10.1053/ajkd.2001.27436 ◽

2001 ◽

Vol 38 (4) ◽

pp. S172-S174 ◽

Cited By ~ 37

Author(s):

Shohei Nakanishi ◽

Junichiro J Kazama ◽

Takashi Shigematsu ◽

Yoshiko Iwasaki ◽

Thomas L Cantor ◽

...

Keyword(s):

Dialysis Patients ◽

Intact Pth ◽

Whole Pth

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A Case of an Ectopic Parathyroid Adenoma With a Concomitant 99mTc-sestamibi-avid Papillary Thyroid Carcinoma

Journal of the Endocrine Society ◽

10.1210/jendso/bvab048.344 ◽

2021 ◽

Vol 5 (Supplement_1) ◽

pp. A170-A171

Author(s):

Maria Nikki Castillo Cruz ◽

Celeste Ong Ramos

Keyword(s):

Parathyroid Gland ◽

Histopathologic Examination ◽

Papillary Thyroid ◽

Thyroid Lobe ◽

Intact Pth ◽

Inferior Aspect ◽

Parathyroid Adenomas ◽

Ectopic Parathyroid ◽

The Right ◽

99Mtc Sestamibi

Abstract Background: The evaluation and management of parathyroid adenomas have improved over the years. Localization of parathyroid adenomas in patients with primary hyperparathyroidism was simplified with the use of 99mTc-sestamibi scintigraphy. In the advent of minimally invasive parathyroid surgery, use of radionuclide probes reduced the need for neck exploration and intraoperative frozen section leading to fewer complications, shorter operative time and hospitalization and rapid postoperative recovery. However, limitations of these techniques should be taken into consideration in certain cases. Clinical Case: A 60 year-old female diagnosed with primary hyperparathyroidism presented with recurrent nephrolithiasis and osteoporosis. Initial laboratory evaluation showed elevated serum calcium and intact PTH (1.54 mmol/L and 146 pg/mL, respectively). 99mTc-sestamibi scintigraphy showed a sestamibi-avid focus in the inferior aspect of the right lobe suggestive of a parathyroid adenoma or hyperplasia. Pre-operative neck ultrasound showed non-specific thyroid parenchymal changes and nodules on both lobes with benign sonographic features. She underwent radionuclide-guided focused right parathyroidectomy. The identified enlarged right inferior parathyroid gland registered a highest reading of 70 cps on radionuclide probe. Post-operatively, repeat intact PTH level was still elevated (171.2 pg/mL). There was an interval non-demonstration of the sestamibi-avid focus in the inferior aspect of the right thyroid lobe with an increased sestamibi uptake in the left thyroid lobe compared to the previous parathyroid scan. Histopathologic examination showed a normocellular parathyroid gland and a multifocal papillary thyroid carcinoma. She underwent total thyroidectomy with central neck dissection and 4 parathyroid gland exploration with intraoperative parathyroid hormone assay. However, serial PTH monitoring after left inferior parathyroidectomy and after bilateral partial superior parathyroidectomy still showed elevated levels. Histopathologic examination showed mildly enlarged, normocellular parathyroid gland. The bilateral carotid sheath, retropharyngeal region and superior mediastinum were explored but no ectopic parathyroid tissues were seen. Post-operatively, calcium and PTH were still elevated (1.48 mmol/L and 200.5 pg/mL, respectively). Conclusion: This case highlights the predicaments in the management of parathyroid adenomas, recognizing the possibility of false-positive sestamibi scans due to malignant thyroid nodules and the possibility of the two diseases occurring concurrently, albeit rare.

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