Lab Test

PTH Related Peptide (Parathyroid Hormone-Related Protein)

PTH-RP, Humoral Hypercalcemia of Malignancy Factor

Test Codes



Pre-chill the specimen tube in a freezer prior to collection. 

Specimen Collection Criteria

Collect: One pre-chilled Lavender-top EDTA tube.

  • Collect specimen on ice.
  • Critical frozen. Send specimen for processing immediately after collection.

Physician Office/Draw Specimen Preparation

Critical frozen. Centrifuge to separate plasma from cells. Immediately transfer plasma to a plastic transport tube and freeze (-20°C/-4°F or below).

Preparation for Courier Transport

Transport: 0.7 mL plasma, frozen (-20°C/-4°F or below). (Minimum: 0.25 mL).

Rejection Criteria

Specimens not collected and processed as indicated.

Inpatient Specimen Preparation

Critical frozen. Place specimen on wet ice and transport to the Laboratory immediately for processing.

In-Lab Processing

Critical frozen. Centrifuge to separate plasma from cells. Immediately transfer plasma to a plastic transport tube and freeze (-20°C/-4°F or below).

Transport: 0.7 mL plasma, frozen (-20°C/-4°F or below). (Minimum: 0.25 mL) 


Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): Unacceptable
Refrigerated (2-8°C or 36-46°F): Unacceptable
Frozen (-20°C/-4°F or below): 30 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.


Sent to Mayo Medical Laboratories, Rochester, MN.


Monday – Thursday.
Results available in 3-6 days.

Reference Range

Less than 4.2 pmol/L.

Test Methodology

Immunochemiluminometric Assay (ICMA).


Increased levels are seen in fetus, newborn and with tumor-associated hypercalcemia. 

This test was developed and its performance characteristics determined by Laboratory Medicine and Pathology, Mayo Clinic Rochester. It has not been cleared or approved by the U.S. Food and Drug Administration.

Clinical Utility

PTH-RP levels are high in approximately 70% of patients with tumor-associated hypercalcemia. This assay may be useful in the differential diagnosis of hypercalcemia, specifically differentiating primary hyperparathyroidism from hypercalcemia related to cancer. PTH-RP may also be used as a marker in the management of patients with solid tumors and hypercalcemia. PTH-RP is not elevated in primary or chronic renal failure.

CPT Codes



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This directory currently reflects information only for specimens collected and/or processed at the
Farmington Hills, Grosse Pointe, Royal Oak, and Troy campuses.