Hereditary Angioedema (HAE)
Also known as: Angioedema Profile, C1 Esterase Inhibitor Deficiency Profile
Use
Aid clinicians in obtaining an appropriate diagnosis of hereditary angioedema (HAE). The profile begins with complement C4 and complement C1 esterase inhibitor with reflexing, if required, to complement C1 esterase inhibitor, functional to distinguish HAE type I from type II. If the results are not consistent with HAE consider other types of angioedema and/or retesting during an acute attack.
Special Instructions
None
Limitations
Rheumatoid factors (>200 IU/mL) significantly increase the apparent C4 concentration. This profile is not intended for the diagnosis of estrogen-dependent, estrogen-associated, drug-induced, or idiopathic angioedema. Additionally, patients taking anabolic steroids may have falsely elevated C4 values, thus limiting the effectiveness of the profile's logic. Consider retesting the patient after discontinuation of anabolic steroids.
Methodology
Immunoassay
Biomarkers
LOINC Codes
- 4477-6
- 4498-2
- 4477-6
Result Turnaround Time
4-6 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
0.5 mL
Minimum Volume
0.1 mL
Container
Gel-barrier tube (preferred) or red-top tube
Collection Instructions
Collect sample on ice. Separate serum from cells in a refrigerated centrifuge. If a refrigerated centrifuge is not available, chill centrifuge tube carriers before centrifuging. Transfer aliquots of serum to each of three plastic transport tubes. Freeze the required 0.5 mL frozen aliquot immediately at -20°C.
Storage Instructions
Frozen sample should not be stored at room temperature (15°C to 30°C) for longer than six hours.
Causes for Rejection
Plasma specimen; specimen not drawn on ice; stored specimen not frozen; gross bacterial contamination; excess lipemia; hemolysis; separate specimens not received (room temperature and frozen)
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | Frozen samples are stable for 14 days. |