Parathyroid Hormone Test

Diagnostic Use

Diagnosis and differential diagnosis of hypercalcemia.

Diagnosis of primary, secondary, and tertiary hyperparathyroidism.

Diagnosis of hypoparathyroidism.

Department

Endocrinology Lab

Delphic Registration Code

RPTH

Laboratory Handling

Phlebotomy

A separate EDTA to CBC samples is preferred.

Separating

PTH is stable for 24hours in unseparated EDTA - please take note if adding PTH to CBC EDTA whole blood samples.

Test Adds

PTH is stable in separated plasma for 2 days at 15-25 C, 3 days at 2- 8 C and 6 months at -20 C. PTH is stable in unseparated plasma for 24 hours.

Synonyms

Parathormone
PTH

Turnaround Time

4 days

Test Code

6508

Specimen Type

• Plasma

Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred if West Coast

• Lithium Heparin - Gel (Light Green Cap)

Acceptable

• Lithium Heparin - Non-gel (Green Cap)
• Lithium Heparin - Gel (Light Green Cap)

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Acceptable

• Lithium Heparin - Non-gel (Green Cap)
• Lithium Heparin - Gel (Light Green Cap)

Interferences

Gross haemolysis - samples will be rejected.

Additional Specimen Information

Plasma stability;
Ambient 2 days
Chilled (2-8 deg) 3 days
Frozen 6 months

Aliquot Instructions

Sample Type

• Plasma

Minimum Volume (ml)

0.3

Transport to Lab

Chilled (2 - 8 degrees Celsius)
If overnight - Chilled (2 - 8 degrees Celsius)

Additional Referral/Aliquot Information

Plasma Aliquot 500 ul. Paediatric Plasma Aliquot 300 ul

West Coast: If specimen is unable to be separated, take blood on PST and send chilled to Greymouth Lab. At Greymouth lab freeze plasma for transport to CHL.

Interpretation

Hypercalcemia with raised or normal PTH: primary or tertiary hyperparathyroidism

Hypercalcemia with low PTH: Hypercalcemia of malignancy (PTHrP-mediated), myeloma, sarcoidosis, vitamin D overdosage, milk-alkali syndrome

Hypocalcemia with raised PTH: Renal failure, Vitamin D or calcium deficiency (rickets, osteomalacia), pseudohypoparathyroidism (PTH resistance)

Hypocalcemia with low or normal PTH: hypoparathyroidism

Reference Intervals

Adults: 1.6 – 7.0 pmol/L

Conversion factor: ng/L x 0.106 = pmol/L

Test Method

Principle: Sandwich type immunoassay with chemiluminescence detection

Analyser: Roche Cobas

Non-Funded Test Cost

$41.97 (Exclusive of GST)

Billing Code

6508

Contact Information

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