Key Features and Values
- Utilises specific antibodies to detect the 1-84 (and long chain) PTH fragments avoiding interference with short inactive fragments
- Low limit of blank allows accurate assessment of low levels of PTH
- Supported by comprehensive panel of vitamin D and PTH assays for complete assessment of calcium metabolism
The Intact PTH ELISA is intended for the quantitative determination of Intact PTH in human serum or plasma and is intended for laboratory use only. Results are to be used in conjunction with other clinical and laboratory data to assist the clinician in the differential diagnosis of hypercalcemia and hypocalcaemia resulting from disorders of calcium metabolism.
Parathyroid hormone (PTH) is a polypeptide hormone of 84 amino acids secreted by the parathyroid glands. Synthesis of PTH is governed by direct negative feedback of ionised calcium on the parathyroid tissues1.
A fall in serum calcium stimulates PTH release, which acts on the kidneys to promote calcium reabsorption and 1,25-dihydroxyvitamin D production. This stimulates bone resorption, restoring serum calcium levels to physiologically acceptable levels2. Measurement of circulating PTH is of particular value in the differential diagnosis of hypercalcaemia, improving the clinical discrimination between patients with hyperparathyroidism and those with hypercalcaemia of malignancy (HCM).
Hyperparathyroidism may be secondary to intestinal malabsorption of calcium or vitamin D deficiency, and is a consistent feature of chronic kidney disease (CKD)3.
1. Potts JT. Parathyroid Hormone: Past and present. J Endocrinology (2005) 187: 311-325.
2. Bringhurst FR., et al: Circulating forms of parathyroid hormone: Peeling back the onion. Clin Chemistry (2003) 49: 1973-1975.
3. Komaba H., et al. Critical issues of PTH assays in CKD. Bone (2009) 45: 514-518