overview
PTH intact test, also known as parathyroid hormone (PTH) 1-84 test, is a blood test that measures the level of parathyroid hormone (PTH) in the blood.
PTH is a hormone that is produced by the parathyroid glands, which are four small glands that are located in the neck, near the thyroid gland. PTH helps to regulate calcium levels in the blood.
Why is PTH intact test done?
PTH intact test is done to diagnose and monitor conditions that affect calcium levels in the blood, such as:
- Hypocalcemia(lower than normal blood calcium levels) or Hypercalcemia( higher than normal blood calcium levels)
- Kidney disease: Serum PTH concentration should be measured regularly in patients with Chronic Kidney Disease (CKD) and maintained within the target ranges that are defined according to the stage of CKD. In patients with CKD, the kidneys are not able to function properly, which can lead to high levels of PTH in the blood. High levels of PTH can lead to a number of problems, including bone loss, kidney stones, stroke.
- Vitamin D deficiency
- osteoporosis : Osteoporosis is a disease in which bones become fragile and more likely to break (fracture).
- Abnormal levels of phosphorus are either low ( hypophosphatemia) or high (hyperphoshatemia)
- Recurrent Kidney stones
PTH assay during surgery of for removal parathyroid gland( parathyroidectomy) :
The determination of PTH intraoperatively during adenoma resection in the parathyroid glands has been reported for primary hyperparathyroidism. This is a procedure called parathyroidectomy, which is used to remove one or more parathyroid glands that are producing too much PTH.
The goal of parathyroidectomy is to normalize calcium levels in the blood. PTH is a hormone that helps to regulate calcium levels in the blood. When a parathyroid gland is removed, the level of PTH in the blood will drop. If the level of PTH drops below a certain level, it is a sign that the adenoma has been removed and that the surgery has been successful.
Intraoperative PTH monitoring is a technique that can be used to help surgeons determine if they have removed the adenoma. In this technique, a blood sample is taken from the patient before the surgery begins. This is the baseline PTH level. Then, blood samples are taken during the surgery at regular intervals. If the level of PTH drops below a certain level, it is a sign that the adenoma has been removed.
Intraoperative PTH monitoring is a useful tool for surgeons who are performing parathyroidectomy. It can help to ensure that the surgery is successful and that the patient’s calcium levels are normalized.
what are sample requirements for PTH test?
There are no special preparations required for a PTH test, but it is always best to check with your health care provider.
| Requirement | Details |
|---|---|
| Specimen | Venous blood sample. |
| Volume | 1- 2mL. |
| Container | Lavender top (EDTA) tube. |
| Transport | Refrigerated (2-8°C). |
| Stability | Plasma: Stable for 2 days at 15‑25 °C, 3 days at 2‑8 °C, 6 months at ‑20 °C (± 5 °C) |
What are the results of PTH intact test?
The results of PTH intact test will be reported in units of pg/mL (picograms per milliliter). The normal range for PTH intact test varies depending on the age and sex of the patient.
Normal reference range for PTH Intact (whole) hormone : 10-65 pg/mL or 10-65 ng/L (SI units)
What does a high PTH intact test result mean?
High PTH levels could be caused by overactive parathyroid glands. This is called hyperparathyroidism
A high PTH intact test result can be due to
- Kidney disease
- Vitamin D deficiency
- parathyroid tumor commonly benign adenoma(noncancerous)
- Medications, such as lithium and thiazide diuretics
- Malabsorption syndrome
What does a low PTH intact test result mean?
Low PTH levels could be related to underactive parathyroid glands (hypoparathyroidism) which can be seen in following conditions
- Injury to the parathyroid glands during thyroid or neck surgery, radiation
- vitamin D Toxicity
- Medications, such as bisphosphonates and calcitonin
- Hypomagnesemia (low levels of magnesium in the blood)
What are sign and symptoms of hyperparathyroidism?
Signs and symptoms of hyperparathyroidism(Higher than normal level of PTH) can be Renal stones, fatigue, muscle weakness, abdominal pain , gastric ulcers ,cardiac arrythmias consult your doctor before doing PTH test
your doctor might order other tests like serum ionised calcium, urinary calcium ,serum vitamin D levels for confirmation of hyperparathyroidism
What are sign and symptoms of hypoparathyroidism?
Signs and symptoms of hypoparathyroidism(lower than normal level of PTH) are Muscle aches or cramps in the legs ,Twitching or spasms of muscles, particularly around the mouth ( due to calcium deficiency),brittle nails.
What is normal function of PTH hormone?
Parathyroid hormone (PTH) is a single-chain 84-amino-acid peptide produced by the parathyroid glands in response to decreased extracellular concentrations of ionized calcium. It has many important roles in the body, including:
- Increasing serum calcium levels by stimulating the release of calcium from bone and its renal re-absorption in the distal tubule.
- Stimulating the synthesis of calcitriol(active vitamin D), which in turn increases intestinal absorption of calcium.
- Increasing the reabsorption of calcium in the distal tubule. This helps to raise serum calcium levels.
- Decreasing the renal re-absorption of phosphate in the proximal tubule, thereby decreasing serum phosphate.
Parathyroid gland disorders can lead to elevated or depressed blood calcium levels (hypercalcemia or hypocalcemia) brought about by a change in the secretion of PTH.
- Hypoparathyroidism is a condition in which the parathyroid glands produce too little PTH, which can lead to low levels of calcium in the blood.
- Hyperparathyroidism is a condition in which the parathyroid glands produce too much PTH, which can lead to high levels of calcium in the blood.
