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22386 C1 Esterase Inhibitor Antigen (C1ES)

C1 Esterase Inhibitor Antigen (C1ES)
Test Code: C1-IHSO
Synonyms/Keywords
C1 Esterase Inhibitor Antigen S, C1 Esterase Inhibitor Quantitative, C1 inhibitor level
Useful For
Diagnosis of hereditary angioedema
Monitoring levels of C1 esterase inhibitor in response to therapy
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
​Preferred, but not required Serum​ ​Red Top Tube (RTT) ​Serum Separator Tube (SST) 1 mL​ 0.5 mL​ ​
Collection Processing 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 Stability Information
Specimen Type Temperature Time
​Serum ​ ​ Frozen (preferred)​ ​28 days
​Ambient ​72 hours
Refrigerated ​ ​28 days
Rejection Criteria
Gross Lipemia
Performing Laboratory Information
Performing Location Day(s) Test Performed Report Available Methodology/Instrumentation
Mayo Clinic Laboratories​​
Monday through Friday
​		 1 to 2 days​
Nephelometry
Reference Lab
Mayo Clinic Laboratories
Reference Range Information
Performing Location Reference Range
Mayo Clinic Laboratories​​
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.

Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
​83883 ​ ​ ​ ​
Synonyms/Keywords
C1 Esterase Inhibitor Antigen S, C1 Esterase Inhibitor Quantitative, C1 inhibitor level
Ordering Applications
Ordering Application Description
​Centricity ​C1 Est. Inh.
​Cerner ​C1 Esterase Inhibitor, Antigen (8198)
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
​Preferred, but not required Serum​ ​Red Top Tube (RTT) ​Serum Separator Tube (SST) 1 mL​ 0.5 mL​ ​
Collection Processing

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 Stability Information
Specimen Type Temperature Time
​Serum ​ ​ Frozen (preferred)​ ​28 days
​Ambient ​72 hours
Refrigerated ​ ​28 days
Rejection Criteria
Gross Lipemia
Useful For
Diagnosis of hereditary angioedema
Monitoring levels of C1 esterase inhibitor in response to therapy
Reference Range Information
Performing Location Reference Range
Mayo Clinic Laboratories​​
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.

For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Report Available Methodology/Instrumentation
Mayo Clinic Laboratories​​
Monday through Friday
​		 1 to 2 days​
Nephelometry
Reference Lab
Mayo Clinic Laboratories
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
​83883 ​ ​ ​ ​
For most current information refer to the Marshfield Laboratory online reference manual.