The prevalence of hereditary angioedema in a Chinese cohort with decreased complement 4 levels

Epidemiology, economic, and humanistic burden of hereditary angioedema: a systematic review

BACKGROUND

This systematic study aims to assess the global epidemiologic, economic, and humanistic burden of illness associated with all types of hereditary angioedema.

METHODS

A systematic search for articles reporting the epidemiologic, economic, and humanistic burden associated with patients with HAE was conducted using English and Chinese literature databases from the inception to May 23, 2022. The selected studies were assessed for their quality and risk of bias. The study was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses and registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD42022352377).

RESULTS

In total, 65 articles that met the search inclusion criteria reported 10,310 patients with HAE, of whom 5861 were female patients. Altogether, 4312 patients (81%) and 479 patients (9%) had type 1 and type 2 HAE, respectively, whereas 422 patients (8%) had HAE-normal C1-INH. The overall prevalence of all types of HAE was between 0.13 and 1.6 cases per 100,000. The mean or median delay from the first onset of a symptom of HAE to confirmed diagnosis ranged from 3.9 to 26 years. The estimated risk of death from asphyxiation was 8.6% for patients with HAE. Hospitalization, medication, unnecessary surgeries, doctor visits, specialist services, and nursing costs are direct expenses that contribute to the growing economic burden. The indirect cost accounted mostly due to missing work ($3402/year) and loss of productivity ($5750/year). Furthermore, impairment of QoL as reported by patient-reported outcomes was observed. QoL measures identified depression, anxiety, and stress to be the most common symptoms for adult patients and children.

CONCLUSION

This study highlights the importance of early diagnosis and the need for improving awareness among health care professionals to reduce the burden of HAE on patients and society.

Epidemiology, Management, and Treatment Access of Hereditary Angioedema in the Asia Pacific Region: Outcomes From an International Survey

BACKGROUND

Hereditary angioedema (HAE) is a rare genetic disease with significant morbidity and mortality for which early diagnosis and effective therapy are critical. Many Asia Pacific (AP) countries still lack access to diagnostic tests and evidence-based therapies. Epidemiologic data from the AP is needed to formulate regional guidelines to improve standards of care for HAE.

OBJECTIVE

To investigate the estimated minimal prevalence, needs, and potential interventions for the diagnosis and management of HAE in the AP.

METHODS

A structured questionnaire was distributed to representative experts from member societies of the Asia Pacific Association of Allergy, Asthma and Clinical Immunology. Patient profiles and the presence of diagnostic facilities or tests, regional and national HAE guidelines, and patient support groups were reported and compared.

RESULTS

Completed questionnaires were received from 14 representatives of 12 member countries and territories, representing 46% of the world population. Overall minimal prevalence of HAE in the AP region was 0.02/100,000 population, with significant heterogeneity across different centers. Only one-half and one-third had registered on-demand and prophylactic medications, respectively. Few had patient support groups (58%) or regional guidelines (33%), and their existence was associated with the availability of HAE-specific medications. Availability of C1-inhibitor level testing was associated with a lower age at HAE diagnosis (P = .017).

CONCLUSIONS

Hereditary angioedema in the AP differs from that in Western countries. Hereditary angioedema-specific medications were registered in only a minority of countries and territories, but those with patient support groups or regional guidelines were more likely to have better access. Asia Pacific-specific consensus and guidelines are lacking and urgently needed.

Prospective Study on the Efficacy and Impact of Cascade Screening and Evaluation of Hereditary Angioedema (CaSE-HAE)

BACKGROUND

Recommendations regarding family screening for hereditary angioedema (HAE) remain variable and mostly based on expert opinion. Studies evaluating its implementation and efficacy are lacking.

OBJECTIVES

A novel HAE screening program was established to evaluate the efficacy and impact of cascade family screening (CFS) for at-risk relatives.

METHODS

Potential HAE relatives were screened through the CFS approach. Prospective data on clinical, psychological, and HAE-related outcomes were collected at baseline and 1-year follow-up. Longitudinal outcomes were analyzed and compared between index patients and those given a diagnosis through CFS.

RESULTS

Of 179 relatives, 53% were contactable, 67% of whom consented to screening. Twenty-nine patients (46%) were newly given the diagnosis of HAE; half were symptomatic at baseline (52%). There was a stronger trend toward higher diagnostic yield among first-degree families, although this did not meet statistical significance (57.6% vs 33.3%; P = .077). Among symptomatic patients, there was a higher proportion with complete annual HAE remission (15% vs 46%; P = .021) and a reduction in annual HAE-related hospital admissions (1 vs 0; P = .016) and length of stay (3 vs 2 days; P = .001) after 1 year. Among all patients, there were reduced Hospital Anxiety and Depression Scale-anxiety (14.35 ± 6.32 vs 6.47 ± 4.14; P = .001) and improved Angioedema Quality of Life scores (55% vs 35%; P < .001). By extrapolation, CFS led to a reduction of at least HK $1,200 (US $153) in HAE-related costs per patient per year. Screening using a greater than suggested C4 cutoff of 22.9 mg/dL yielded superior sensitivity (100%) and specificity (77%).

CONCLUSION

Cascade family screening is an effective approach to family screening in HAE, improving clinical and psychological outcomes, and reducing disease-related costs.