How is it used?
ACE is primarily ordered to help diagnose and monitor . It is often ordered as part of an investigation into the cause of a group of troubling symptoms that may or may not be due to sarcoidosis. ACE will be elevated in 50% to 80% of patients with active sarcoidosis. If it is initially elevated in someone with sarcoidosis, ACE can be ordered at regular intervals to monitor the course of the disease and the effectiveness of corticosteroid treatment.
When is it requested?
ACE is ordered when you have or such as granulomas, a cough or shortness of breath, red watery eyes, and/or joint pain that may be due to sarcoidosis or to another disorder. This is especially true if you are between 20 and 40 years of age, when sarcoidosis is most frequently seen. Your doctor may order ACE, along with other tests such as an AFB culture or culture (tests that can detect mycobacterial and fungal infections), when it is necessary to differentiate between sarcoidosis and another granulomatous condition.
If you have been diagnosed with sarcoidosis and your initial ACE levels were elevated, your doctor may order ACE testing at regular intervals to monitor their change over time.
What does the test result mean?
Serum ACE levels are a nonspecific indicator of granulomatous disease. They do not tell you why the levels are elevated, what organs and/or body systems are involved, or to what degree. ACE does not cause granulomas, but it often reflects their presence.
If ACE levels are high, other diseases have been ruled out, and you have clinical findings consistent with sarcoidosis, then it is likely that you have an active case of sarcoidosis. About 20-50% of the time, however, sarcoidosis can be present without elevated ACE levels. This may be due to the disease being in an inactive state, due to early detection of sarcoidosis (before the levels have risen), or due to the granuloma cells not secreting increased amounts of ACE. ACE levels are also less likely to be elevated in those with chronic sarcoidosis.
High levels of ACE which then fall generally indicate improvement in the disease, either due to treatment or to the sarcoidosis clearing up spontaneously. Rising levels of ACE on the other hand, may indicate either an early disease process, or disease activity that is not responding to therapy.
ACE levels are often higher in healthy children and young adolescents than in adults, and do not, generally, indicate sarcoidosis.
Is there anything else I should know?
Conversion of angiotensin I to angiotensin II by ACE is a normal regulatory process in the body. This process has been targeted by the development of drugs called ACE inhibitors that are commonly used in treating hypertension and diabetes. These drugs inhibit the conversion process, keeping the blood vessels more dilated and the blood pressure lower. ACE inhibitors are useful in managing hypertension, but they are not monitored with ACE blood tests. They may, however, interfere with ACE measurements ordered for other reasons.
and in the blood sample may falsely decrease ACE levels. Decreased ACE levels may also be seen in patients with:
- Chronic obstructive pulmonary disease (COPD)
- Lung cancer
- Steroid drug therapy
ACE has been found in moderately increased levels in a variety of diseases and disorders such as:
The ACE test, however, is not routinely used to diagnose or monitor these conditions as it has not been shown to be clinically useful.