Test Center

My Recent Searches

  • No Recent Search.

My Tests Viewed

  • No Test Viewed.
Test Name

C1 Inhibitor, Functional

CPT Code(s)

86161

Methodology

Immunoassay

Limitations

Fifteen percent of patient with the inherited form of the disease will test within range.

Reference Range(s)

≥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.

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.

Test FAQ

C1 Inhibitor, Protein and Functional Tests

Alternative Name(s)

Functional C1-Inhibitor,C1 Esterase

To view specimen requirements and codes please Select a regional laboratory.

Not sure which laboratory serves your office? Call us 866-MYQUEST (866-697-8378)

Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.

The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

* The tests listed by specialist are a select group of tests offered. For a complete list of Quest Diagnostics tests, please refer to our Directory of Services.

44768P
297X
297
297
297
297
297X
297
297
297X
21950
297
297
297
297
297
297
23042
297
297
297
297
297X
44768P
297
44768P
297X
21950
297
297X
297
C1 Inhibitor, Functional
297