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Angiotensin Converting Enzyme (ACE), Cerebrospinal Fluid

CPT: 82164
Updated on 08/3/2021
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Expected Turnaround Time

4 - 5 days

3 - 5 days

4 - 5 days


Related Documents


Specimen Requirements


Specimen

Cerebrospinal fluid (CSF), frozen


Volume

0.5 mL


Minimum Volume

0.2 mL


Container

Plastic (CSF) tube


Collection

Collect CSF by lumbar puncture.


Storage Instructions

Transport frozen.

Transport frozen.

Transport frozen.

Transport frozen.

Transport frozen.


Stability Requirements

Temperature

Period

Room temperature

14 days

Refrigerated

14 days

Frozen

14 days

Freeze/thaw cycles

Stable x3

Temperature

Period

Room temperature

14 days

Refrigerated

14 days

Frozen

14 days

Freeze/thaw cycles

Stable x3

Temperature

Period

Room temperature

14 days

Refrigerated

14 days

Frozen

14 days

Freeze/thaw cycles

Stable x3

Temperature

Period

Room temperature

14 days

Refrigerated

14 days

Frozen

14 days

Freeze/thaw cycles

Stable x3

Temperature

Period

Room temperature

14 days

Refrigerated

14 days

Frozen

14 days

Freeze/thaw cycles

Stable x3


Causes for Rejection

Hemolysis


Test Details


Use

Quantitative measurement of ACE in CSF. Angiotensin Converting Enzyme (ACE) is used in the assessment of neurosarcoidosis. The major sources of ACE are macrophages and epithelial cells. Patients with sarcoidosis display elevated levels of ACE.


Limitations

Results of this test are labeled for research purposes only by the assay's manufacturer. The performance characteristics of this assay have not been established by the manufacturer. The result should not be used for treatment or for diagnostic purposes without confirmation of the diagnosis by another medically established diagnostic product or procedure. The performance characteristics were determined by LabCorp.


Methodology

Quantitative spectrophotometry


Reference Interval

See table.

Age

Range (U/L)

0 to 5 y

Not established

6 to 17 y

0.0−2.1

18 to 50 y

0.0−2.5

>50 y

0.0−3.1


Additional Information

Angiotensin-converting enzyme catalyzes the formation of angiotensin II by cleaving the C-terminal histidylleucine dipeptide from angiotensin I.1

Indications are that ACE is affiliated with an autonomous renin-angiotensin system of the brain that participates in physiologic processes inside the brain.2,3 Also, studies suggest that changes in ACE concentrations in brain tissue, caused by various neurologic disorders, are reflected by alterations in ACE activity in cerebrospinal fluid (CSF).4

Increased ACE concentrations in CSF are associated with neurosarcoidosis,4-7 with affected patients generally having activities approximately two-fold or more higher than those of healthy individuals.4,6,7

Increased CSF ACE has also been implicated in neurologic diseases, such as bacterial and viral meningitis and Behcet disease.4-7

Decreased concentrations have been reported in patients with Alzheimer disease, Parkinson disease, and progressive supranuclear palsy.8,9


Footnotes

1. Soffer RL. Angiotensin-converting enzyme and the regulation of vasoactive peptides. Annu Rev Biochem. 1976;45:73-94.183603
2. Printz MP, Ganten D, Unger T, Phillips MI. Mini review: the brain renin angiotensin system. In: Ganten D, Printz MP, Phillips MI, Scholkens BA, eds. The renin-angiotensin system in the brain. Heidelberg: Springer Verlag, 1982:3-52.
3. Phillips MI, Weyhenmeyer J, Felix D, Ganten D, Hoffman WE. Evidence for an endogenous brain renin-angiotensin system. Fed Proc. 1979 Aug;38:2260-2266.222621
4. Schweisfurth H, Schioberg-Schiegnitz S. Assay and biochemical characterization of angiotensin-I-converting enzyme in cerebrospinal fluid. Enzyme. 1984;32(1):12-19.6090116
5. Chan Seem CP, Norfolk G, Spokes EG. CSF angiotensin converting enzyme in neurosarcoidosis. Lancet. 1985 Feb 23;1(8426):456-457.2857830
6. Oksanen V, Fyhrquist F, Somer H, Gronhagen-Riska C. Angiotensin converting enzyme in CSF: a new assay. Neurology. 1985 Aug;35(8):1220-1223.2991815
7. Jones DB, Mitchell D, Horn DB, Edwards CR. Cerebrospinal fluid angiotensin converting enzyme levels in the diagnosis of neurosarcoidosis. Scott Med J. 1991 Oct;36(5):144-145.1664971
8. Zubenko GS, Volicer L, Direnfeld LK, Freeman M, Langlais PJ, Nixon RA. Cerebrospinal fluid levels of angiotensin-converting enzyme in Alzheimer's disease, Parkinson's disease and progressive supranuclear palsy. Brain Res. 1985 Mar 4;328(2):215-221.2985183
9. Zubenko GS, Marquis JK, Volicer L, Direnfeld LK, Langlais PJ, Nixon RA. Cerebrospinal fluid levels of angiotensin-converting enzyme, acetylcholinesterase, and dopamine metabolites in dementia associated with Alzheimer's disease and Parkinson's disease: a correlative study. Biol Psychiatry. 1986 Dec;21(14):1365-1381.3024746

LOINC® Map

Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
123231 ACE, CSF 12480-0 123232 ACE, CSF U/L 12480-0

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