Test Code C1ES C1 Esterase Inhibitor Antigen, Serum
Reporting Name
C1 Esterase Inhibitor Antigen, SUseful For
Diagnosis of hereditary angioedema
Monitoring levels of C1 esterase inhibitor in response to therapy
Performing Laboratory

Specimen Type
SerumSpecimen Required
Patient Preparations: Fasting preferred but not required.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
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 aliquot serum into plastic vial.
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 |
Reference Values
19-37 mg/dL
Day(s) Performed
Monday through Friday
Test Classification
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
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 |
Method Description
In this Siemens Nephelometer II method, the light scattered onto the antigen-antibody complexes is measured. The intensity of the measured scattered light is proportional to the amount of antigen-antibody complexes in the sample under certain conditions. If the antibody volume is kept constant, the signal behaves proportionally to the antigen volume.
A reference curve is generated by a standard with a known antigen content on which the scattered light signals of the samples can be evaluated and calculated as an antigen concentration. Antigen-antibody complexes are formed when a sample containing antigen and the corresponding antiserum are put into a cuvette. A light beam is generated with a light-emitting diode, which is transmitted through the cuvette. The light is scattered onto the immuno-complexes that are present. Antigen and antibody are mixed in the initial measurement, but no complex is formed yet. An antigen-antibody complex is formed in the final measurement.
The result is calculated by subtracting value of the final measurement from the initial measurement. The distribution of intensity of the scattered light depends on the ratio of the particle size of the antigen-antibody complexes to the radiated wavelength.(Instruction manual: Siemens Nephelometer II Operations. Siemens, Inc; Version 2.4, 07/2019)
Report Available
2 to 5 daysReject Due To
Gross hemolysis | OK |
Gross lipemia | Reject |
Gross icterus | OK |
Method Name
Nephelometry