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Test Code C1IHN C1 Esterase Inhibitor, Protein

Additional Codes

Epic: LAB2970

Quest: 298

Specimen Required

Specimen Type: Serum

Collection Container/Type

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Specimen Minimum Volume

0.5 mL

Specimen Stability

Room temperature: 7 days
Refrigerated: 8 days
Frozen: 1 year

Reference Range

21-39 mg/dL

Day(s) and Time(s) Performed

Mon-Sat p.m.

Report Available

Next day

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.

Method Name

Nephelometry

CPT Code(s)

86160

Performing Laboratory

Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153