Understanding HAE

Dariela, a real HAE patient, helps prevent her attacks with CINRYZE.

Diagnosing HAE

Watch HAE expert Dr. Douglas Johnston discuss how the disease is diagnosed.

When It Might Be HAE
Douglas T. Johnston, D.O., FAAAAI, FACAAI

Hereditary angioedema (HAE) is under-recognized and frequently misdiagnosed as another condition.1 While about 40% of patients are now diagnosed within the first 3 years of experiencing symptoms, approximately one third of patients still experience delays of 10 years or more.*2,3

* In a survey of 149 patients.

Misdiagnosis is common*4

Up to
65%
misdiagnosed

One survey showed that up to 65% of HAE patients have been previously misdiagnosed with another condition.*4 Most commonly, subcutaneous attacks are mistaken for allergic reactions. Abdominal attacks are frequently mistaken for appendicitis or irritable bowel syndrome.1 In fact, in a survey from 2010, up to 19% of patients in the United States underwent unnecessary procedures as a result of misdiagnosis, including removal of appendix.*4

* In a survey of 313 patients

Early diagnosis can help ensure proper management of HAE

Many factors play key parts in correctly diagnosing HAE. Examining the patient's family history can provide important insight, since 75% of patients with HAE inherit the disease from a parent.5 Diagnosis is made through a comprehensive evaluation that should include family history, clinical history, and laboratory testing.6,7

Proper diagnosis can provide patients with the education necessary to manage HAE during daily life, including4:

  • Identification and avoidance of triggers
  • Preparation for attacks
  • Timely response to potentially lethal complications, such as airway obstruction

Confirming an HAE diagnosis

To confirm an HAE diagnosis, laboratory testing is necessary. Patients should have serum levels of C4 measured, because levels are invariably low (C4 <30% of mean normal level) in patients with HAE who have not yet been treated. When these values are low, antigenic and functional C1-INH levels should be tested.1,7,8

Diagnostic algorithm for the evaluation of recurrent angioedema9

Recurrent angioedema flowchart

Type 1: C1-inhibitor deficiency
Type 2: C1-inhibitor dysfunction
*CINRYZE (C1 esterase inhibitor [human]) is not indicated for acquired C1-inhibitor deficiency.

Though referenced Allergy and Asthma Proceedings material is used with permission, this site was not formally reviewed by, and is not endorsed by, the authors or publisher of the referenced work and does not convey the full and complete results of the original article.

Examples of HAE laboratory tests by provider

QUEST DIAGNOSTICS

Test Name Laboratory Code CPT Code
Angioedema Panel, Hereditary, Comprehensive (Panel includes all tests below) 17706 86160 (x2), 86161
Complement Component C4c 353 86160
C1 Esterase Inhibitor, Protein 298 86160
C1-Inhibitor, Functional 297 86161
Complement Component C1q 981 86160

LABCORP

Test Name Laboratory Code CPT Code
Hereditary Angioedema (HAE) (Panel includes all tests below) 123020 86160 (x2)
Complement C4, Serum 001834 86160
Complement C1 Esterase Inhibitor, Serum 004648 86160
Complement C1 Esterase Inhibitor, Functional 120220 86161
Complement C1q, Quantitative 016824 86160

NATIONAL JEWISH (ADX)

Test Name Laboratory Code CPT Code
C4 Level C4 86160
C1 Esterase Inhibitor Level (C1-INH) CEIQ 86160
C1-Inhibitor (C1-INH) Function, Chromogenic Assay CEICHR 86161
C1q Level C1Q 86160

EXSERA BIOLABS

Test Name Laboratory Code CPT Code
C1-INH Chromogenic Function C1INHF 86161
Intact C4 C4LMX 86160
Total C4 C4IM 86160
C1q Level C1QLMX 86160

Current as of March 2018.

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References

  1. Banerji A. The burden of illness in patients with hereditary angioedema. Ann Allergy Asthma Immunol. 2013;111(5):329–336.
  2. Zuraw BL. Clinical practice. Hereditary angioedema. N Engl J Med. 2008;359(10):1027–1036.
  3. Banerji A, Busse P, Christiansen SC, et al. Current state of hereditary angioedema management: A patient survey. Allergy Asthma Proc. 2015;36(3):213.
  4. Lunn ML, Santos CB, Craig TJ. Is there a need for clinical guidelines in the United States for the diagnosis of hereditary angioedema and the screening of family members of affected patients? Ann Allergy Asthma Immunol. 2010;104(3):211–214.
  5. Altman KA, Naimi DR. Hereditary angioedema: a brief review of new developments. Curr Med Res Opin. 2014;30(5):923-930.
  6. Bowen T, Cicardi M, Farkas H, et al. 2010 International consensus algorithm for the diagnosis, therapy and management of hereditary angioedema. Allergy Asthma Clin Immunol. 2010;6(1):24.
  7. Maurer M, Magerl M, Ansotegui I, et al. The international WAO/EAACI guideline for the management of hereditary angioedema – the 2017 revision and update [published online ahead of print January 10, 2018]. Allergy. doi:10.1111/all.13384.
  8. Gompels MM, Lock RJ, Abinun M, et al. C1 inhibitor deficiency: consensus document. Clin Exp Immunol. 2005;139(3):379–394.
  9. Zuraw BL, Christiansen SC. Pathogenesis and laboratory diagnosis of hereditary angioedema. Allergy Asthma Proc. 2009;30(5):487–492.

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