Skip to main content

Specimen Collection Manual and Test Catalog

  or
  or
  or

C1 ESTERASE INHIBITOR, FUNCTIONAL

Geisinger Epic Procedure Code:  LAB1905    Geisinger Epic ID:  14834

SPECIMEN COLLECTION
Specimen type: 

Serum


Preferred collection container: 
Specimen required: 

1 ml aliquot of serum; minimum 0.2 mL. Please submit a separate frozen aliquot for this test. It may not be combined with any other test requiring a frozen aliquot.


Special notes: 

Freeze serum within 1 hour of time drawn. Do not use gel barrier tubes. Do not submit sample in a glass tube. Freeze and ship frozen. Do not thaw.



SPECIMEN PROCESSING
Processing instructions: 

Centrifuge 10 minutes at 3000 rpm.


Transport temperature: 

Frozen.


Specimen stability: 

Room temperature: Unacceptable. Refrigerated: Unacceptable. Frozen: 1 month at -20°C.


Rejection criteria: 

Room temperature and refrigerated specimens are unacceptable. Gel barrier tubes (SST) are unacceptable.



TEST DETAILS
Interpretation guide: 

> or = 68% Normal
41-67% Equivocal
< or = 40% Abnormal
Less than 40% of the reference functional activity indicates a likely diagnosis of hereditary angioedema or acquired C1 Inhibitor deficiency.


CPT code(s):  86161
Note: The billing party has sole responsibility for CPT coding.  Any questions regarding coding should be directed to the payer being billed.
The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.

Test includes: 

C1 Inhibitor, Functional


Methodology: 
Enzyme Immunoassay (EIA)
Synonyms: 

Complement C1 EI Panel Functional, C1 Inactivator,C1 Esterase Inhibitor ,, Quest test code 297, C1ESIF


Clinical significance: 

C1 esterase is decreased in angioedema. The inherited form is usually diagnosed in the first two decades of life. The acquired form affects primarily adults with autoimmune or lymphoproliferative disorders. Approximately 15% of patients with hereditary angioedema have a normal concentration of the protein but it is dysfunctional.


Review Date:  11/28/2024

Performing Locations