Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
Calcitonin, a polypeptide hormone of 32 amino acids, is secreted by the parafollicular (or C) cells of the thyroid gland. Calcitonin exerts its biological effect by acting on three target organs: bone, kidney and the GI tract. The principal physiological action in bone is the inhibition of bone resorption resulting from the binding of calcitonin to specific receptors on the osteoclasts. In the kidney, calcitonin increases urinary clearance of calcium and phosphate. The effect of calcitonin on the GI tract is unclear.
Plasma calcitonin measurements are important in the diagnosis and monitoring of medullary thyroid cancer (MTC). MTC accounts for 5-10% of thyroid cancers and arises from the parafollicular C cells, which secrete calcitonin. Although it is a rare disease, MTC is often associated with a poor prognosis. Around 80% of cases are sporadic and it is also associated with the inherited syndromes MEN 2a, MEN 2b and familial MTC.
Specimen container paediatric:
Lithium heparin plasma
Specimen container adult:
Lithium heparin plasma
Minimum volume paediatric:
1 mL blood
Minimum volume adult:
1 mL blood
Special requirements:
Sample taken on ice. To be separated within 30 minutes.
Sample stability:
Unseparated sample: 30 minutes
Separated sample:
4 hours at 20 to 25°C,
1 day at 2 to 8°C,
3 months at -20°C
Transport requirements:
Frozen
Interpretation:
Although raised concentrations of plasma calcitonin are diagnostically sensitive for MTC, elevated calcitonin may be seen in a number of other conditions including hypercalcaemia, hypergastrinaemia, neuroendocrine tumours, renal insufficiency and also secondary to medications such as PPIs, beta-blockers and glucocorticoids.
Reference ranges:
Adult Female: <6 ng/L
Adult Male: <10 ng/L
Other info:
Serum and EDTA plasma samples also acceptable