Angiotensin-Converting Enzyme (ACE) Test – Detailed Guide

The Angiotensin-Converting Enzyme (ACE) Test measures the level of ACE enzyme in the blood. ACE is mainly produced by the lungs and kidneys and plays a role in regulating blood pressure by converting angiotensin I to angiotensin II, a hormone that constricts blood vessels.

This test is primarily used to diagnose and monitor sarcoidosis, a disease that causes inflammatory cell clusters (granulomas) in various organs.

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Why is the ACE Test Done?

✅ To Diagnose & Monitor Sarcoidosis

• Sarcoidosis is an inflammatory disease affecting the lungs, lymph nodes, skin, and eyes
• Elevated ACE levels suggest active sarcoidosis
• Helps track disease progression and treatment response

✅ To Identify Other Conditions with Granulomas

• Tuberculosis (TB)
• Leprosy
• Berylliosis (lung disease from exposure to beryllium)
• Fungal infections (like histoplasmosis)

✅ To Evaluate Lung & Autoimmune Disorders

• Pulmonary fibrosis (lung scarring)
• Gaucher’s disease (genetic disorder affecting organs)
• Diabetes mellitus complications

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Test Procedure

🩸 Blood Sample Collection:

• A blood sample is drawn from a vein
• No fasting required
• Avoid ACE-inhibitor medications (e.g., Lisinopril, Enalapril) before the test if instructed by your doctor
• Results available in 1–3 days

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Normal ACE Levels

🔹 Reference ranges may vary slightly between laboratories.

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What Do Abnormal ACE Levels Mean?

🔴 High ACE Levels May Indicate:

• Sarcoidosis (especially if levels remain persistently high)
• Tuberculosis (TB)
• Leprosy
• Gaucher’s Disease
• Pulmonary Fibrosis (scarring of the lungs)
• Lymphoma (certain blood cancers)
• Hyperthyroidism (overactive thyroid)

🟢 Low ACE Levels May Indicate:

• Use of ACE Inhibitor Medications (e.g., Lisinopril, Enalapril)
• Chronic kidney disease (CKD)
• Severe liver disease (cirrhosis)
• Hypothyroidism (underactive thyroid)

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Next Steps If ACE Levels Are Abnormal?

🔬 Further Tests May Be Needed:

• Chest X-ray or CT Scan – To check for lung granulomas (sarcoidosis)
• Pulmonary Function Tests (PFTs) – To assess lung health
• Calcium & Kidney Function Tests (Creatinine, BUN) – Sarcoidosis can cause high calcium levels
• Biopsy of Affected Tissue – To confirm sarcoidosis if suspected

✅ Treatment Depends on the Underlying Condition

• For Sarcoidosis: Steroids (Prednisone), immunosuppressants if severe
• For Tuberculosis: Anti-TB medications
• For Lung Diseases: Oxygen therapy, pulmonary rehabilitation