Days Set Up
Monday - Saturday
Analytic Time

2 - 4 days

MiChart Code
C1 Esterase Inhibitor, Antigen
Soft Order Code

Test Updated:


C1 Esterase Inhibitor Quantitative
Complement C1 Esterase Inhibitor, Antigen
HAE (Hereditary Angioedema)
Hereditary Angioedema (HAE)

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Test Overview

Test Methodology


Test Usage

Diagnosis of hereditary angioedema and monitoring levels in response to therapy. Abnormally low results are consistent with a heterozygous C1 inhibitor deficiency. Normal (or elevated) levels with a nonfunctional protein are detected in 15% of hereditary angioedema patients (detection of these patients requires the functional assay).

Reference Range

19 - 37 mg/dL

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Specimen Requirements

Collection Onsite

Collect blood in a red top or SST tube. A fasting speciment is preferred but not required (12 hour fast). Send the specimen to Specimen Processing in a green bag. Must be spun and frozen within 30 minutes after collection.

Collection Offsite

Collect blood in a red top or SST tube. A fasting speciment is preferred but not required (12 hour fast). Centrifuge, aliquot serum into a plastic vial and freeze immediately. Thawed specimens or those stored at room temperature are unacceptable. Do not refreeze thawed specimens; may be refrigerated up to 3 days.

Yellow Top Tube
Normal Volume
1.0 mL serum
Minimum Volume
0.5 mL serum

Billing Information

CPT Code
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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.