Parathyroid hormone-related protein blood test
What is the Parathyroid Hormone-Related Protein Blood Test?
The Parathyroid Hormone-Related Protein Blood Test (also known as the PTH-RP test) measures the amount of parathyroid hormone-related protein (PTHrP) present in the blood. PTHrP helps regulate the body's calcium balance and is produced by certain cells in the body that are not related to the parathyroid glands. The test is used to diagnose and monitor conditions that affect the parathyroid glands and bones, and to help identify tumors that produce PTHrP.
Preparation for the Test
Typically there is no special preparation for the PTH-RP blood test. You should inform your doctor and the laboratory of any medications you are taking, such as antibiotics or blood thinners, which could affect test results.
The Procedure
The procedure for obtaining a sample for the PTH-RP blood test is the same as for routine blood tests. A health care provider will take a sample of blood from a vein in your arm, typically following the standard protocol for drawing blood. Then the sample is sent to a laboratory for analysis.
Types of PTH-RP Blood Tests
There are two types of PTH-RP blood tests: a total PTH-RP test, which measures the total PTHrP in the blood; and a free PTH-RP test, which measures only the free, or unbound, PTHrP in the blood. Free PTH-RP tests are more accurate and are commonly used to diagnose certain conditions, such as hyperparathyroidism. Total PTH-RP tests are typically used to monitor the effectiveness of treatments for those conditions.
Risks of the Test
The risks of the PTH-RP blood test are low and rare. However, as with any test involving the drawing of blood, there is a risk of infection or allergic reaction to the needle or other substances used, such as the antiseptic used to clean the area where the sample is taken.
Why is the Test Performed?
The test is typically performed to diagnose and/or monitor conditions that affect the parathyroid glands and bones, such as hyperparathyroidism, hypercalcemia, and some types of tumors. It is also used to help identify tumors that produce PTHrP.
When is the Test Performed?
Your doctor may order the test if you are showing symptoms of a parathyroid disorder, such as bone pain or fatigue. It may also be ordered if a tumor is suspected.
