Parathyroid Hormone (PTH), Intact

Test Code

PTH

Alias/See Also

Epic: LAB108

Preferred Specimen

Specimen Type: Serum red
Collection Container: Red top
Specimen Volume: 3 mL

Minimum Volume

0.5 mL

Other Acceptable Specimens

Specimen Type: Plasma
Collection Container: Green top (Lithium heparin) (No gel)

Instructions

Centrifuge and aliquot serum into a plastic vial within 4 hours of collection.

Transport Container

Plastic vial

Specimen Stability

Room temperature: Unacceptable
Refrigerated: 48 hours
Frozen: 6 months

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Specimens collected in SST tubes, specimens collected in gel separator tubes, unlabeled, mislabeled, wrong tube type, hemolyzed, QNS, exceeds specimen stability requirements.

Methodology

Chemiluminescent microparticle immunoassay (CMIA)

Setup Schedule

Daily

Report Available

Same day

Limitations

If the iPTH results are inconsistent with clinical evidence, additional testing is suggested to confirm the result.
Heterophilic antibodies in human serum can react with reagent immunoglobulins, interfering with in vitro immunoassay.
This assay has not been clinically validated for intraoperative use.

Reference Range

18.0 - 89.0 pg/mL

Clinical Significance

PTH is secreted by the parathyroid gland. The concentration of intact PTH is independent of the GFR and reflects the biologically active portion of the hormone. The primary role of PTH is to regulate blood Ca levels. The biological activity of PTH is to increase absorption of dietary calcium, decrease renal clearance and mobilize skeletal calcium stores. High calcium concentrations suppress secretion of PTH.
In conjunction with serum calcium levels, PTH is used as an aid in the differential diagnosis of hypercalcemia, hypocalcemia, and parathyroid disease. PTH determination is important in monitoring dialysis patients to manage renal osteodystrophy.

Performing Laboratory

Inova Laboratories

2832 Juniper Street

Fairfax, VA 22031

Last Updated: October 3, 2023
Last Review: N. Wolford, October 3, 2023

The CPT Codes provided in this document 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 payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.