Hereditary Angioedema (HAE)

Casandra

Casandra Test Code LC48985Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 123020CPT Code 86160

Hereditary Angioedema (HAE)

Also known as: Angioedema Profile, C1 Esterase Inhibitor Deficiency Profile

Clinical Use

Order Test

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

Not provided.

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.

Test Details

Methodology

Immunoassay

Biomarkers

3 components

Complement C4, SerumComplement C1 Esterase Inhibitor, SerumC1 Esterase Inhibitor, Functional

LOINC Codes

Order Codes

4477-6

Result Codes

4498-2
4477-6

Result Turnaround Time

4-6 days

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)