Test Details
Methodology
Immunologic
Result Turnaround Time
3 - 6 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Test Includes
Complement C4, serum; complement C1 esterase inhibitor, serum; and automatic reflex to complement C1 esterase inhibitor, functional (at additional charge) if the C1 esterase inhibitor result is ≥21 mg/dL.
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.
Limitations
Rheumatoid factors (>200 IU/mL) significantly increase the apparent C4 concentration. This profile is not intended for the diagnoses of estrogen-dependent, estrogen-associated, drug-induced, or idiopathic angioedema. Also note that 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.
Specimen Requirements
Specimen
Serum, frozen and room temperature
Volume
Three aliquots: one tube 0.5 mL frozen, two tubes 1 mL each at room temperature
Minimum Volume
Three aliquots: one tube 0.1 mL frozen, two tubes 0.5 mL each at room temperature
Container
Gel-barrier tube (preferred) or red-top tube. Note: Since specimen must be drawn on ice, plain red-top tubes will not clot as well as the use of clot-activated gel tubes.
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. Required room temperature samples are stable for three days, frozen samples for 14 days.
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)
References
LOINC® Map
Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
---|---|---|---|---|---|---|
123020 | Hereditary Angioedema (HAE) | 4477-6 | 001833 | Complement C4, Serum | mg/dL | 4498-2 |
123020 | Hereditary Angioedema (HAE) | 4477-6 | 004649 | C1 Esterase Inhibitor, Serum | mg/dL | 4477-6 |
Order Code | 123020 | |||||
Order Code Name | Hereditary Angioedema (HAE) | |||||
Order Loinc | 4477-6 | |||||
Result Code | 001833 | |||||
Result Code Name | Complement C4, Serum | |||||
UofM | mg/dL | |||||
Result LOINC | 4498-2 | |||||
Order Code | 123020 | |||||
Order Code Name | Hereditary Angioedema (HAE) | |||||
Order Loinc | 4477-6 | |||||
Result Code | 004649 | |||||
Result Code Name | C1 Esterase Inhibitor, Serum | |||||
UofM | mg/dL | |||||
Result LOINC | 4477-6 |
Order Code | Order Name | Result Code | Result Name | UofM | Result LOINC | |
---|---|---|---|---|---|---|
Reflex 1 | 120219 | C1 Esterase Inhibitor, Func | 120222 | C1 Est.Inhib.Funct. | %mean normal | 10634-4 |
Reflex 1 | ||||||
Order Code | 120219 | |||||
Order Name | C1 Esterase Inhibitor, Func | |||||
Result Code | 120222 | |||||
Result Name | C1 Est.Inhib.Funct. | |||||
UofM | %mean normal | |||||
Result LOINC | 10634-4 |
Order Code | Order Name | Result Code | Result Name | UofM | Result LOINC | |
---|---|---|---|---|---|---|
Reflex 1 | 120219 | C1 Esterase Inhibitor, Func | 120222 | C1 Est.Inhib.Funct. | %mean normal | 10634-4 |
Reflex 1 | ||||||
Order Code | 120219 | |||||
Order Name | C1 Esterase Inhibitor, Func | |||||
Result Code | 120222 | |||||
Result Name | C1 Est.Inhib.Funct. | |||||
UofM | %mean normal | |||||
Result LOINC | 10634-4 |
Order Code | Order Name | Result Code | Result Name | UofM | Result LOINC | |
---|---|---|---|---|---|---|
Reflex 1 | 120219 | C1 Esterase Inhibitor, Func | 120222 | C1 Est.Inhib.Funct. | %mean normal | 10634-4 |
Reflex 1 | ||||||
Order Code | 120219 | |||||
Order Name | C1 Esterase Inhibitor, Func | |||||
Result Code | 120222 | |||||
Result Name | C1 Est.Inhib.Funct. | |||||
UofM | %mean normal | |||||
Result LOINC | 10634-4 |
Order Code | Order Name | Result Code | Result Name | UofM | Result LOINC | |
---|---|---|---|---|---|---|
Reflex 1 | 120226 | HAE Interpretation: | 120226 | HAE Interpretation: | 56850-1 | |
Reflex 1 | ||||||
Order Code | 120226 | |||||
Order Name | HAE Interpretation: | |||||
Result Code | 120226 | |||||
Result Name | HAE Interpretation: | |||||
UofM | ||||||
Result LOINC | 56850-1 |