C1 Esterase Inhibitor Protein

Last Modified: 11/23/2022 12:46:20 PM

Medical Necessity Documentation:  
Client Notes:  
Patient Preparation:  
Specimen Requirements:

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

Collection Instructions:  
Minimum Volume: 0.5 mL
Transport & Storage: Temperature/Stability: 7 days Ambient (Transport)
8 days Refrigerated
1 year Frozen
Reference Range: 21 - 39 mg/dL
Critical Ranges:  
Test Comments: Limitations;Fifteen percent of patient with the inherited form of the disease will test within range.
Methodology: Nephelometry
Clinical Significance:

The C1 esterase inhibitor protein is a normal constituent of serum which functions as a serine proteinase inhibitor of the serpin family. The C1 esterase inhibitor inhibits the complement proteases C1r and C1s, as well as the proteases kallikrein, factor XIa, XIIa and plasmin of the blood clotting system. The concentration of C1 esterase inhibitor protein is reduced to 10-30% of normal in patients with angioedema secondary to C1 esterase inhibitor deficiency (85% of patients with Hereditary Angioedema (HAE)); In 15% of patients with HAE, the concentrations of the inhibitor protein is normal but function is markedly reduced.

Custom Panel: No


Turn Around Time: 3 to 5 days
Days Performed: Monday, Tuesday, Wednesday, Thursday, Friday, Saturday
Sites Performed: Quest - Chantilly
PHL Test Code: C1EST
EPIC Test Code: LAB2522
Send Out Test Code: 298
Alternate Test Names: C1 Esterase; C1 Esterase Inhibitor, Total; C1 Inhibitor Protein
Included Tests:  
CPT Coding: 86160

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