ACE Level (Angiotensin-Converting Enzyme)
The ACE Level Test measures the amount of Angiotensin-Converting Enzyme (ACE) in your blood serum. ACE is an enzyme produced primarily in the lungs and, to a lesser extent, the kidneys and vascular endothelium. Its main biological role is in the Renin-Angiotensin-Aldosterone System (RAAS), where it converts Angiotensin I into the powerful vasoconstrictor, Angiotensin II, thereby regulating blood pressure.
Clinically, the ACE test is primarily used as a non-specific diagnostic marker for Sarcoidosis, a chronic inflammatory disease.
Why Do You Need This Test?
The ACE Level Test is most commonly ordered to:
- Diagnose Sarcoidosis: Elevated ACE levels are found in approximately $50\%$ to $80\%$ of patients with active, untreated sarcoidosis. The level is believed to be released by the epithelioid cells of the granulomas (clumps of immune cells) that characterize the disease.
- Monitor Sarcoidosis Activity: Tracking the level is helpful, as ACE tends to fall when the disease is stable or responding to treatment (e.g., steroids) and rise during a disease relapse.
- Differentiate Causes of Pulmonary Disease: Helping distinguish sarcoidosis from other lung or granulomatous diseases (like tuberculosis, where ACE levels are usually normal or low).
