C1-Esterase Inhibitor
Also known as: C1ESTER
Use
The C1-Esterase Inhibitor test aids in the diagnosis of hereditary angioedema, a genetic condition characterized by episodes of severe swelling, and in monitoring the response to therapy. It helps evaluate the levels of the C1 inhibitor protein in the blood, which is crucial in regulating the complement and contact system pathways of immune response. Deficiency or dysfunction of this inhibitor can lead to increased production of bradykinin, contributing to the symptoms of angioedema.
Special Instructions
Ensure serum separation from cells as soon as possible, ideally within two hours of collection, and transfer to an ARUP Standard Transport Tube for stability. Specimen should be refrigerated during transport. Avoid ambient temperature exposure as it is unacceptable for this test.
Limitations
This test does not differentiate between genetic (hereditary) and acquired causes of C1 inhibitor deficiency. Results need to be interpreted in conjunction with clinical symptoms and other laboratory studies to determine the exact cause of C1 inhibitor deficiency. Grossly hemolyzed or lipemic serum samples are unacceptable and can lead to erroneous results. Also, the test is not suitable if samples are stored at ambient temperature post-collection, as they may degrade and give inaccurate results.
FDA ApprovedNew York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 4477-6
Result Turnaround Time
1-4 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Serum should be separated from cells as soon as possible, within 2 hours of collection.
Storage Instructions
Transport refrigerated.
Causes for Rejection
Ambient temperature and grossly hemolyzed or lipemic specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Unacceptable |
| Refrigerated | 14 days |
| Frozen | 1 month |