Hereditary Angioedema With Normal C1 Inhibitor: US Survey of Prevalence and Provider Practice Patterns

Marc A Riedl; Mark Danese; Sherry Danese; Julie Ulloa; Andreas Maetzel; Paul K Audhya

doi:10.1016/j.jaip.2023.01.023

Hereditary Angioedema With Normal C1 Inhibitor: US Survey of Prevalence and Provider Practice Patterns

J Allergy Clin Immunol Pract. 2023 Aug;11(8):2450-2456.e6. doi: 10.1016/j.jaip.2023.01.023. Epub 2023 Jan 30.

Authors

Marc A Riedl¹, Mark Danese², Sherry Danese², Julie Ulloa², Andreas Maetzel³, Paul K Audhya⁴

Affiliations

¹ Division of Rheumatology, Allergy, and Immunology, University of California, San Diego, Calif. Electronic address: mriedl@health.ucsd.edu.
² Outcomes Insights, Inc, Agoura Hills, Calif.
³ Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
⁴ KalVista Pharmaceuticals, Inc, Cambridge, Mass.

PMID: 36720386
DOI: 10.1016/j.jaip.2023.01.023

Abstract

Background: Hereditary angioedema (HAE) with normal C1-INH (HAE-nl-C1INH) is phenotypically similar to HAE resulting from C1-INH deficiency (HAE-C1INH). Confirmatory diagnostic tests for HAE-nl-C1INH are limited and few clinical study data exist regarding management of the condition. Therefore, survey studies may provide initial estimates of prevalence, diagnosis, and management patterns of this condition.

Objective: To estimate the prevalence and describe current management patterns for HAE-nl-C1INH in the United States (US).

Methods: We conducted an Internet-based survey of US physicians to estimate the prevalence of the HAE-nl-C1INH population in the United States. Potential participating physicians were identified from the US Hereditary Angioedema Association database and IQVIA Xponent prescription database. Eligible physicians were invited to complete an online survey between June and September 2021.

Results: A total of 113 physicians provided data for the estimation of HAE-nl-C1INH prevalence and 81 physicians treating HAE-nl-C1INH patients provided data about treatment patterns. In bias-corrected analysis, we estimated 1,230 to 1,331 HAE-nl-C1INH patients within the United States between May 2019 and April 2020. Mean time to diagnosis for HAE-nl-C1INH was approximately 6 years (range, 2.4-13.5 years). Response to medication was commonly used to inform diagnosis (antihistamine response or nonresponse used by 73% of physician respondents, corticosteroids by 57%, or HAE-specific medications by 74%), and Factor XII genetic testing was used by 43%.

Conclusions: These survey data provide estimates of HAE-nl-C1INH prevalence in the United States as well as current diagnosis and management strategies. Results may be useful for developing studies to assess treatment efficacy and safety, and potentially improve the diagnosis for and management of this patient population.

Keywords: Diagnostics; Hereditary angioedema; Management; Normal C1 HAE; Prevalence; Treatment.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Angioedemas, Hereditary* / diagnosis
Angioedemas, Hereditary* / drug therapy
Angioedemas, Hereditary* / epidemiology
Complement C1 Inhibitor Protein / genetics
Complement C1 Inhibitor Protein / therapeutic use
Factor XII / genetics
Genetic Testing
Humans
Prevalence
Surveys and Questionnaires
United States / epidemiology

Substances

Complement C1 Inhibitor Protein
Factor XII