Parathyroid Hormone (PTH), Intact

Cleveland Heartlab P, Test

CPT Code: 83970
Order Code: C309
ABN Requirement:  No
Synonyms: PTH Intact; PTHI
Specimen: EDTA Plasma 
Volume: 1.5 mL
Minimum Volume: 1.0 mL
Container: EDTA (Lavender Top) tube


EDTA Plasma:

  1. Draw and gently invert 8 to 10 times.
  2. Centrifuge for 10 minutes.
  3. Pre-squeeze transfer pipet bulb and draw off approximately 2/3 of the upper plasma layer.
    Note: This ensures that the buffy coat and red cells remain undisturbed.
  4. Aliquot plasma into transport tube labeled as “EDTA Plasma” and cap tightly. Discard original tube.
  5. Store transport tube refrigerated at 2-8°C until ready to ship.

Transport: Store EDTA plasma at 2°C to 8°C after collection and ship the same day per packaging instructions included with the provided shipping box.


Ambient (15-25°C): 2 days
Refrigerated (2-8°C): 3 days
Frozen (-20°C): 6 months

Causes of Rejection: Hemolyzed samples; specimens other than EDTA plasma; improper labeling; samples not stored properly; samples older than stability limits; grossly hemolyzed specimen; grossly lipemic specimen

Methodology: Immunoassay (IA)

Turn Around Time: 5 days

Reference Range:


<1 Year7-58
1-7 Years12-55
8-18 Years12-71
≥19 Years14-64

Clinical Significance: A parathyroid hormone test can be used to determine the cause of calcium or phosphorus imbalances, to evaluate bone disorders and to diagnose and differentiate parathyroid dysfunction including primary and secondary hyperparathyroidism and hypoparathyroidism.

Limitations: For assays employing antibodies, the possibility exists for interference by heterophile antibodies in the patient sample. Patients who have been regularly exposed to animals or have received immunotherapy or diagnostic procedures utilizing immunoglobulins or immunoglobulin fragments may produce antibodies, e.g. HAMA, that interfere with immunoassays. Additionally, other heterophile antibodies such as human anti-goat antibodies may be present in patient samples. Such interfering antibodies may cause erroneous results. Carefully evaluate the results of patients suspected of having these antibodies. Results should be interpreted in light of the total clinical presentation of the patient, including: symptoms, clinical history, data from additional tests, and other appropriate information.

The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.