Acid phosphatase (ACP)

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:
This test usually does not require special preparation. As with any blood test, the health care provider may limit certain foods or medications shortly before the test to assure an accurate sample.

Drugs that can interfere with ACP measurements include fluorides, oxalates, clofibrate, and alcohol.

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 is most often performed to determine whether you have prostate cancer , an abnormality of the prostate gland, or to follow the response of cancer to treatment.

Acid phosphatase is an enzyme in the lysosomes of cells throughout the body. ACP is in especially high concentrations in the prostate. Prostatic dysfunction results in the release of ACP into the blood.

Normal Values:
Values of 0 to 0.8 U/L are normal.

Note: U/L = units per liter

Abnormal Results:



Cost:
The estimated cost is $40 to $60.

Special Considerations:
Prostate cancer , located only in the prostate gland, may not produce high enough levels to indicate a problem. This is one of the best blood tests for prostate cancer (50 to 75% accurate), but a physical examination is much more reliable.

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.