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Test ID: PTH
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Parathyroid Hormone Intact
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Useful For
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For the differential diagnosis of hypercalcemia and hypocalcemia and for monitoring patients undergoing treatment for kidney disease, hyperparathyroidism, and hypoparathyroidism.
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Method name and description
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Electrochemiluminescence immunoassay (ECLIA): Sandwich principle
Electrochemiluminescence immunoassay (ECLIA) intended for use on the cobas e 801 immunoassay analyzer. Patient sample biotinylated monoclonal PTH‑specific antibody, a monoclonal PTH‑specific antibody labeled with a ruthenium complex and streptavidin-coated microparticles react to form a sandwich complex, which is bound to the solid phase. The reaction mixture is aspirated into the measuring cell where the microparticles are magnetically captured onto the surface of the electrode. Unbound substances are then removed with ProCell II M. Application of a voltage to the electrode then induces chemiluminescent emission which is measured by a photomultiplier. Results are determined via a calibration curve which is instrument specifically generated by 2‑point calibration and a master curve.
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Clinical information
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Parathyroid hormone (PTH) is an amino-acid peptide produced by the parathyroid glands. Its main role is to increase serum calcium levels by stimulating the release of calcium from bone and its renal re-absorption in the distal tubule. Parathyroid gland disorders lead to elevated or depressed blood calcium levels (hypercalcemia or hypocalcemia) brought about by a change in the secretion of PTH. Hyperfunctioning of the parathyroid glands results in an increased secretion of PTH (hyperparathyroidism). Primary causes are adenomas of the parathyroid glands. In secondary hyperparathyroidism the blood calcium level is low as a result of other pathological states (e.g. vitamin D deficiency). The determination of PTH intraoperatively during adenoma resection in the parathyroid glands has been reported for primary hyperparathyroidism, secondary hyperparathyroidism relating to renal failure. (Roche Cobas PTH package insert ; Roche Diagnostic Corp., Indianapolis, IN)
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Specimen type / Specimen volume / Specimen container
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Specimen type: Serum, Plasma
Minimum volume of sample: 1 mL
Serum: Plain tube (red or yellow top, seperare serum immediately)
Plasma: Li‑heparin, K2‑EDTA and K3‑EDTA tube
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Collection instructions / Special Precautions / Timing of collection
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PTH was found to be stable for > 24 hours at room temperature in whole blood anticoagulated with EDTA. Preference should be given to EDTA plasma.
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Storage and transport instructions
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Storage: 8 hours at 15 – 25°C (serum)
2 days at 15 – 25°C (plasma)
2 days at 2 – 8°C (serum)
3 days at 2 – 8°C (plasma)
3 months at ‑15 to -25 °C (serum and plasma)
Transport: 2-25°C
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Specimen Rejection Criteria
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Grossly hemolyzed, icteric and lipemic samples, wrong collection container, insufficient sample and heat‑inactivated samples.
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Biological reference intervals and clinical decision values
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Turnaround time / Days and times test performed / Specimen retention time
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Daily (24/7)
Turn-around time:
STAT: 1 hour
Routine: One working day
Specimen Retention: 4 days
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