Angiotensin Converting Enzyme

1. Sarcoidosis (Most Important Laboratory Use)

Serum ACE levels are elevated in ~60–90% of active sarcoidosis cases.

Granuloma macrophages produce excess ACE.

Clinical utility:

• Supports diagnosis (not confirmatory)
• Reflects disease activity
• Useful for monitoring response to therapy

⚠️ Normal ACE does not exclude sarcoidosis.

2. Other Granulomatous & Inflammatory Diseases

ACE may also be elevated in:

• Tuberculosis
• Leprosy
• Histoplasmosis
• Berylliosis

➡️ Hence, ACE is not specific to sarcoidosis.

3. Pulmonary and Systemic Disorders

Elevated ACE seen in:

• Interstitial lung disease
• Chronic liver disease
• Hyperthyroidism
• Diabetes mellitus

4. Decreased ACE Levels

Low ACE levels may be seen in:

• Patients receiving ACE inhibitors
• Chronic obstructive pulmonary disease (COPD)
• Hypothyroidism
• Advanced liver disease

5. Role in Hypertension & Heart Failure (Therapeutic Target)

ACE is the target of ACE inhibitors (e.g., captopril, enalapril).

ACE inhibition leads to:

• ↓ Angiotensin II
• ↓ Aldosterone
• ↑ Bradykinin

Clinical benefits:

• Treatment of hypertension
• Heart failure management
• Diabetic nephropathy protection
• Post-myocardial infarction remodeling prevention