Parathyroid Hormone Intact (iPTH), EDTA Plasma

Parathyroid hormone (PTH) is secreted by parathyroid glands. It is also called as parathormone or parathyri. Parathyroid hormone plays an importantrole in bone remodeling, where bone tissue is reabsorbed and rebuild alternatively. PTH is secreted by the parathyroid glands when calcium levels are low in the blood. PTH stimulates osteoclastic activity in bone, which results in the release of calcium (Ca2+) into the blood. This causes elevation of serum calcium levels. Hyperparathyroidism is the presence of excessive amounts of parathyroid hormone in the blood. It is of two types, primary and secondary. Primary hyperparathyroididm is due to increased secretion of parathormone by parathyroid glands. Secondary hyperparathyroidism is an abnormally high PTH levels seen as a response to hypocalcaemia. Low levels of PTH in the blood is known as hypoparathyroidism, seen due to damage to or removal of parathyroid glands. Parathyroid hormone (PTH) test is often ordered along with calcium test to assess the balance between serum calcium levels and PTH levels and measure the response of the parathyroid glands to changes in the levels of serum calcium. Parathyroid hormone (PTH) levels can also be used to monitor people with chronic calcium imbalances or any treatment for a parathyroid tumor.

1. Can a person with abnormal parathyroid hormone levels be asymptomatic?

Yes, as calcium levels change slowly, a person may not have any symptoms. In such cases abnormal parathormone levels may be detected when serum calcium levels are tested.

2. What is the relation between vitamin D and PTH?

Vitamin D enables calcium absorption. Vitamin D regulates absorption of calcium from the intestine. Parathormone regulates vitamin D activation.

3. What is intraoperative PTH and when is it done?

Intraoperative PTH test is done while a person is undergoing surgery for parathyroid gland. A surgery is done to remove enlarged parathyroid gland(s) in cases of hyperparathyroidism, to ensure complete removal of the abnormal glands.