Definition of ACE levels:

ACE levels is a blood test that measures the amount of angiotensin-converting enzyme (ACE).

How the test is performed:

Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

After the blood has been drawn, it goes to a laboratory to be evaluated.

How to prepare for the test:

You may have to restrict food and fluids for up to 12 hours before the test. People taking steroid therapy should talk to their health care providers, because steroids can decrease ACE levels.

How the test will feel:

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.

Why the test is performed:

ACE levels can be used in the evaluation of sarcoidosis and some other diseases. People with sarcoidosis may have their ACE levels tested regularly to check the severity of the disease and to monitor the response to therapy. This test also helps confirm Gaucher's disease and leprosy.