C1 Inhibitor, Functional

Overview

  • EPIC Code:
  • Soft Test Code:
  • MSOT
  • Send Out Test Code:
  • 297
Alternate Names
  • C1 Esterase
  • Functional C1-Inhibitor
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.


Specimen Collection & Preparation

Specimen Requirements

1.0 mL Frozen Serum from a Red Top Tube in a Plastic Vial

Alternate Specimen

 

TransportAndStorage

30 days Frozen

Collection Instructions

Freeze serum within 1 hour of time drawn

Clinical Interpretation

Reference Range:

≥68 % Normal
41-67 % Equivocal
≤40 % Abnormal
Less than 40% of the reference functional activity indicates a likely diagnosis of hereditary angioedema or acquired C1 inhibitor deficiency.


Test Comments:

limitations: Fifteen percent of patients with the inherited form of the disease will test within range.


Methodology:
  • Immunoassay (IA)

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.


Production Schedule

Sites Performed
  • Quest - Chantilly
Days Performed
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Departments
  • Sendouts - Miscellaneous
Turn Around Time

2 to 3 days


Coding & Compliance

CDM

00913333


CPT Coding

86161