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PTH-like peptide How the Test is Performed:
Adult or child:
Blood is drawn from a vein ( venipuncture ), usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and a tourniquet (an elastic band) or blood pressure cuff is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the tourniquet to distend (fill with blood). A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the tourniquet is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding .
Infant or young child:
The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.
How to Prepare:
Adults:
No special preparation is necessary.
Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:
How it Feels:
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing .
Risks:
- excessive bleeding
- fainting or feeling lightheaded
- hematoma (blood accumulating under the skin)
- infection (a slight risk any time the skin is broken)
- multiple punctures to locate veins
Why this Test is Performed:
This test may be used to predict persons (particularly individuals with cancer ) who are at risk to develop hypercalcemia (high blood calcium levels).
Many people with malignancies develop hypercalcemia. Hypercalcemia secondary to cancer is a fairly common medical emergency. Bone metastasis is the cause in many cases, however, a significant number of people who develop hypercalcemia secondary to cancer do not demonstrate significant bone metastasis. About two thirds of cancer patients with hypercalcemia have elevated levels of a protein molecule that is similar to PTH (PTH-like peptide).
Normal Values:
No detectable (or minimal) PTH-like peptide is normal.
Abnormal Results:
Elevated levels of PTH-like peptide may indicate impending calcium abnormalities in a person with cancer .
Elevated levels of PTH-like peptide in a person who has normal calcium levels may, in some cases, indicate a tumor that has not yet been discovered.
Cost:
The estimated cost is $91.
Special Considerations:
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
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