Lab Information Manual

PARATHYROID HORMONE (PTH) - RELATED PEPTIDE - (P)

Test Code: PHRP

Parathyroid hormone-related peptide (PTHrP) testing is used in the assessment of patients with hypercalcemia of unknown origin and in suspected humoral hypercalcemia of malignancy.
PTHrP is produced by most tissues and is structurally similar to PTH, allowing it to bind to the same receptors. Hypercalcemia of malignancy, a common complication of cancer, is caused by elevations of PTHrP. This leads to hypercalcemia by stimulating calcium resorption from bone and reabsorbtion in the kidneys. PTHrP also plays a significant role in osteolysis in bony metastases, particularly in breast cancer.

Preferred Device:

Plasma: 1.0 mL

Pediatric Plasma: 0.7 mL

Collect blood in an ice-cooled EDTA tube and send immediately to lab on ice for processing.
Stability 30 days frozen.

_SH General Endocrinology Requisition (R250-10-76)

_SH Specialized Endocrinology Requisition (R250-10-77)

≤ 4.2 pmol/L

  For more information:
PTHrP  - Mayo Medical Laboratories

Within 2 Weeks

Spin down in a refrigerated centrifuge or in chilled centrifuge cups.  Separate and freeze within 2hr of collection.  Store and send EDTA plasma frozen in a plastic vial to Mayo Medical Laboratories (MML).  If the specimen thaws, it is unsuitable for analysis.