Parathyroid Hormone (PTH), Intact

Test ID: 

704256

CPT code:

83970

Synonyms:

•PTH Whole Molecule

Clinical Use:

Diagnosis of parathyroid disease and other diseases of calcium homeostasis; monitoring patients undergoing renal dialysis

Specimen Type:

PTH is an 84-amino-acid peptide hormone which is responsible for the regulation of serum calcium levels within a narrow range. PTH is secreted in response to decrease in serum calcium levels by increasing the renal reabsorption of calcium and lowering reabsorption of phosphorus. The measurement of PTH is a very useful tool in the differential diagnosis and management of hypercalcemia. PTH assays can be of help in the diagnosis of tumors and hyperplasia of the parathyroid gland, as well as in localizing hyperfunctioning parathyroid tissue by assay of samples obtained via venous catheterization. The native or intact (1-84) PTH has a short half-life, measured in minutes, whereas the carboxy and midmolecule fragments, which are biologically inactive, have half-lives 10- to 20-fold higher. The high concentrations of biologically inactive fragments have interfered with use of C-terminal or midmolecule assays for evaluation of parathyroid function in patients with impaired renal function. Intact PTH assays provide a more accurate assessment of parathyroid patients including those with various renal diseases.

Requested Volume: 

1.5 mL

Minimum Volume: 

0.7 mL

Container Type: 

Lavender-top (EDTA) tube (preferable)

Collection:

Transfer separated plasma into a plastic transport tube clearly labeled as “EDTA Plasma” and maintain at refrigerated temperature.

Storage Instructions:

Refrigerate (preferable)

Rejection Criteria: 

Whole blood; plasma other than EDTA; hemolysis; room temperature or refrigerated serum.