Test Catalog

Test Id : ACE

Angiotensin Converting Enzyme, Serum

Useful For
Suggests clinical disorders or settings where the test may be helpful

Evaluation of patients with suspected sarcoidosis

Method Name
A short description of the method used to perform the test

Spectrophotometry (SP)

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Angiotensin Converting Enzyme, S

Lists additional common names for a test, as an aid in searching

Angiotensin-1-Converting Enzyme

Kinase II

Peptidylpeptide Hydrolase

SACE (Serum Angiotensin Converting Enzyme)


Serum Angiotensin Converting Enzyme

ACE (Angiotensin Converting Enzyme)

Specimen Type
Describes the specimen type validated for testing


Necessary Information

The use of angiotensin converting enzyme (ACE)-inhibiting antihypertensive drugs will cause decreased ACE values. Patients taking ACE inhibitors, such as captopril and enalapril, will have extremely low or unmeasurable ACE activity. Indicate on the request form if the patient is on ACE inhibitors.

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial


If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-General Request (T239)

-Cardiovascular Test Request (T724)

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.

0.5 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 7 days
Frozen 180 days
Ambient 24 hours

Useful For
Suggests clinical disorders or settings where the test may be helpful

Evaluation of patients with suspected sarcoidosis

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Angiotensin converting enzyme (ACE) is integral to the renin-angiotensin system (RAS), which maintains blood pressure by regulation of fluid volume and vascular tension. Its peptidase action on the decapeptide angiotensinogen I results in the hydrolysis of a terminal histidyl leucine dipeptide and the formation of the octapeptide angiotensin II, a potent vasoconstrictor that increases blood pressure.


ACE activity is increased in sarcoidosis, a systemic granulomatous disease that commonly affects the lungs. In sarcoidosis, ACE is thought to be produced by epithelioid cells and macrophages of the granuloma.


ACE activity reflects the severity of sarcoidosis: 68% positivity in those with stage I sarcoidosis, 86% in stage II sarcoidosis, and 91% in stage III sarcoidosis.


Other conditions such as Gaucher disease, leprosy, untreated hyperthyroidism, psoriasis, premature infants with respiratory distress syndrome, adults with amyloidosis, and histoplasmosis have been associated with increased serum ACE activity.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

> or =18 years: 16-85 U/L

0-17 years: Angiotensin converting enzyme activity may be 20-50% higher in healthy children compared to healthy adults.


For SI unit Reference Values, see https://www.mayocliniclabs.com/order-tests/si-unit-conversion.html

Provides information to assist in interpretation of the test results

An elevation in the level of serum angiotensin converting enzyme (ACE), along with radiographic evidence of infiltrates or adenopathy and organ biopsies showing noncaseating epithelial granulomas is suggestive of a diagnosis of sarcoidosis.


Normal, healthy children and infants are known to have ACE activity levels greater than the adult reference interval.

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Spinal fluid angiotensin converting enzyme (ACE) activity to aid the diagnosis of neurosarcoidosis has been reported; however, there is insufficient evidence to support ACE being used for this purpose.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Liebermann J: Elevation of serum angiotensin-converting-enzyme (ACE) level in sarcoidosis. Am J Med. 1975;59:365-372

2. Rodriguez GE, Shin BC, Abernathy RS, Kendig EL Jr: Serum angiotensin-converting enzyme activity in normal children and in those with sarcoidosis. J Pediatr. 1981;99:68-72

3. Personal observations from a Mayo pediatric normal range study using a manual method (Hana)

4. Maguire GA, Price CP: A continuous monitoring spectrophotometric method for the measurement of angiotensin-converting enzyme in human serum. Ann Clin Biochem. 1985;22:204-210

5. Allen DW, Rajagopal V: Other adjunctive drugs for coronary intervention: beta-blockers, calcium-channel blockers, and angiotensin-converting enzyme inhibitors. In: Tropol EJ, Teirstein P, eds. Textbook of Interventional Cardiology. 8th ed. Elsevier; 2020:214-222

Method Description
Describes how the test is performed and provides a method-specific reference

Angiotensin converting enzyme (ACE) catalyzes the conversion of angiotensin I to angiotensin II. The enzyme also mediates the cleavage of the synthetic substrate N-(3-[2-furyl]acryloyl)-L-phenylalanylglycylglycine (FAPGG) into an amino acid derivative and a dipeptide. The kinetic of this cleavage reaction is measured by recording the decrease in absorbance at 340 nm.(Package insert: Buhlmann ACE Kinetic; 01/2013)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

1 to 3 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

7 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their account representative. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
ACE Angiotensin Converting Enzyme, S 2742-5
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
ACE Angiotensin Converting Enzyme, S 2742-5

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports