The angiotensin converting enzyme (ACE) is an enzyme that converts angiotensin I to angiotensin II. Angiotensin II helps increase blood pressure by causing small blood vessels in the body to tighten or narrow.
Doctors can determine ACE levels by performing a simple blood test known as the angiotensin converting enzyme (ACE) level test.
Doctors most often use the ACE level test to monitor a disease called sarcoidosis. This condition causes inflammatory cells called granulomas to form in the body, leading to organ inflammation. Organs that may be affected by sarcoidosis include the:
- lymph nodes
People with sarcoidosis may experience fatigue, fever, and unexplained weight loss. Other symptoms include:
- night sweats
- a loss of appetite
- swollen lymph nodes
- joint pain
- dry mouth
The granulomas associated with sarcoidosis increase the amount of ACE in the blood. A doctor may use the ACE level test to help confirm a sarcoidosis diagnosis or to monitor treatment for sarcoidosis.
Your doctor may also use the ACE level test to assess the effectiveness of treatments for other medical conditions. One condition that may be monitored with an ACE level test is Gaucher’s disease. This is an inherited condition that causes fatty substances called lipids to build up in cells and internal organs. Symptoms include easy bruising, fatigue, and bone pain. High levels of the ACE enzyme can suggest you have Gaucher’s disease and can also be used to track response to medical therapy.
Other conditions that may cause lower-than-normal ACE levels include:
- chronic obstructive pulmonary disease (COPD)
- cystic fibrosis
Conditions that may cause higher-than-normal levels of ACE include:
- Gaucher’s disease
While an ACE level test can help reveal signs of underlying medical conditions, the test is rarely used to diagnose these conditions. Other tests are usually done along with an ACE level test before a diagnosis is confirmed.
The ACE level test doesn’t require any special preparations. You won’t need to fast or refrain from taking any prescription or over-the-counter medications before the test is completed. However, you may want to notify your healthcare provider about any blood-thinning medications you may be taking. They may need to hold some extra pressure on the puncture site after the blood draw to ensure you don’t experience excessive bleeding.
The ACE level test involves taking a small sample of blood from a vein in your arm. During a blood draw, the following steps will occur:
- To take your blood, a healthcare provider will put a tight band known as a tourniquet around your arm. This will make your veins easier to see.
- After cleaning the desired area with an antiseptic, they’ll insert the needle. You may feel a slight prick or stinging sensation when the needle goes in. However, the test itself isn’t painful.
- The blood is collected in a tube or vial attached to the end of the needle.
- Once enough blood has been collected, they’ll remove the needle and apply pressure to the puncture site for a few seconds.
- They’ll then put a bandage or gauze over the area where the blood was drawn.
- After the test, your blood sample is sent to a laboratory for testing.
- Your doctor will follow up with you to discuss the results.
The ACE level test carries few risks. Some people have a slight bruise or experience soreness around the area where the needle was inserted. However, this usually goes away within a few days. Call your doctor if you experience severe bruising, discomfort, or pain after the test.
Other, more serious complications from blood tests can also occur, but this is very rare. Such complications include:
- excessive bleeding
- fainting or dizziness
- blood accumulating under the skin, which is called a hematoma
- infection at the puncture site
ACE level test results can vary based on the laboratory that performs the analysis. When you receive your results, you should receive a reference range that defines normal ACE levels. In most cases, the reference range is 8 to 53 microliters for adults. The reference range for ACE levels in children can much higher depending on the laboratory that did the testing.
Higher-than-normal ACE levels may indicate sarcoidosis. After treatment for sarcoidosis, your ACE levels should decrease. High levels may also be signs of another underlying medical condition, such as cirrhosis or diabetes.
Lower-than-normal ACE levels may indicate that sarcoidosis is responding to treatment and may be in remission. ACE levels can also be low if you are taking ACE-inhibiting medications, such as captopril or Vasotec. However, if ACE levels start to rise even after treatment for sarcoidosis, this could mean that the disease is progressing or that the disease isn’t responding to treatment. In these cases, your doctor will work to determine a more effective treatment plan for your condition.
It’s important to note that the ACE level test isn’t the only test that’s used to diagnose sarcoidosis. Some people may have normal ACE levels and still have sarcoidosis, while others may have high ACE levels and not have sarcoidosis. Other tests that may be used to confirm a sarcoidosis diagnosis include a liver panel, complete blood count (CBC), and calcium levels.
Regardless of your results, it’s critical to speak with your doctor about what they may mean for you specifically.