Parathyroid Hormone, Intact
Also known as: PTH-INT
Use
Parathyroid hormone (PTH) measurement is crucial for evaluating parathyroid gland function, primarily in conditions like hypercalcemia or hypocalcemia. The test aids in diagnosing primary or secondary hyperparathyroidism, as well as hypoparathyroidism. PTH levels, in conjunction with calcium and phosphate levels, help in assessing bone turnover rates and calcium homeostasis. Normocalcemic patients can have varying PTH levels based on their vitamin D status. This test is particularly useful for patients suspected to have parathyroid gland disorders or those with vitamin D insufficiency or resistance.
Special Instructions
This test requires immediate centrifugation of serum samples post-clotting to maintain PTH stability. Separate specimens must be submitted if multiple tests are ordered. Ensure to transport specimens under frozen conditions to prevent instability.
Limitations
Parathyroid hormone is unstable in unseparated serum, which necessitates immediate centrifugation post-clotting if serum is used instead of plasma. Hemolyzed or lipemic samples may result in inaccurate PTH levels, and thus such specimens are unsuitable for testing. Body fluid specimens apart from designated blood types are also unacceptable, which limits extension of this test beyond its intended use.
New York Approved
Methodology
Immunoassay (ECLIA)
Biomarkers
LOINC Codes
- 2731-8
- 2731-8
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
2 mL
Minimum Volume
0.5 mL
Container
Lavender (K2 or K3EDTA) or pink (K2EDTA) tube.
Storage Instructions
Specimens should be transported frozen.
Causes for Rejection
Body fluid, urine, rapid serum tubes (RST), hemolyzed samples, grossly lipemic samples.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 8 hours |
| Refrigerated | 48 hours |
| Frozen | 6 months |