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Test Code 0204735 C1 Esterase (C1ES) Inhibitor Antigen, Serum

Additional Codes

Mayo Test ID
C1ES

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Diagnosis of hereditary angioedema

 

Monitoring levels of C1 esterase inhibitor in response to therapy

Method Name

Nephelometry

Reporting Name

C1 Esterase Inhibitor Antigen, S

Specimen Type

Serum


Specimen Required


Patient Preparations: Fasting preferred but not required.

Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Immediately after specimen collection, place the tube on wet ice.

2. Centrifuge and separate serum from clot.

3. Freeze specimen within 30 minutes.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Frozen (preferred) 28 days
  Refrigerated  28 days
  Ambient  72 hours

Reject Due To

Hemolysis

Mild OK; Gross OK

Lipemia

Mild OK; Gross reject

Icterus

Mild OK; Gross OK

Other

NA

Reference Values

19-37 mg/dL

Interpretation

Abnormally low results are consistent with a heterozygous C1 esterase inhibitor deficiency and hereditary angioedema.

 

Fifteen percent of hereditary angioedema patients have a normal or elevated level but nonfunctional C1 esterase inhibitor protein. Detection of these patients requires a functional measurement of C1 esterase inhibitor; FC1EQ / C1 Esterase Inhibitor, Functional Assay, Serum.

 

Measurement of C1q antigen levels; C1Q / Complement C1q, Serum, is key to the differential diagnoses of acquired or hereditary angioedema. Those patients with the hereditary form of the disease will have normal levels of C1q, while those with the acquired form of the disease will have low levels.

 

Studies in children show that adult levels of C1 inhibitor are reached by 6 months of age.

Day(s) and Time(s) Performed

Monday through Saturday; Continuously until 3 p.m.

Analytic Time

1 day

Specimen Retention Time

14 days

Test Classification

This test has been cleared or approved by the U.S. 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

83883

LOINC Code Information

Test ID Test Order Name Order LOINC Value
C1ES C1 Esterase Inhibitor Antigen, S 4477-6

 

Result ID Test Result Name Result LOINC Value
C1ES C1 Esterase Inhibitor Antigen, S 4477-6