Assessment and management of disease burden and quality of life in patients with hereditary angioedema: a consensus report.

BACKGROUND: Hereditary angioedema (HAE) is a rare disease characterized by unpredictable, potentially life-threatening attacks, resulting in significant physical and emotional burdens for patients and families. To optimize care for patients with HAE, an individualized management plan should be considered in partnership with the physician, requiring comprehensive assessment of the patient's frequency and severity of attacks, disease burden, and therapeutic control. Although several guidelines and consensus papers have been published concerning the diagnosis and treatment of HAE, there has been limited specific clinical guidance on the assessment of disease burden and quality of life (QoL) in this patient population. Practical guidance is critical in supporting effective long-term clinical management of HAE and improving patient outcomes. The objective of this review is to provide evidence-based guidelines for an individualized assessment of disease burden and QoL in patients with HAE. METHODS: A consensus meeting was held on February 29, 2020, consisting of 9 HAE experts from the United States and Europe with extensive clinical experience in the treatment of HAE. Consensus statements were developed based on a preliminary literature review and discussions from the consensus meeting. RESULTS: Final statements reflect the consensus of the expert panel and include the assessment of attack severity, evaluation of disease burden, and long-term clinical management of HAE caused by C1-esterase inhibitor deficiency. Patient-reported outcome measures for assessing HAE attack severity and frequency are available and valuable tools; however, attack frequency and severity are insufficient markers of disease severity unless they are evaluated in the broader context of the effect on an individual patient's QoL. QoL assessments should be individualized for each patient and minimally, they should address the interference of HAE with work, school, social, family, and physical activity, along with access to and burden of HAE treatment. Advances in HAE therapies offer the opportunity for comprehensive, individualized treatment plans, allowing patients to achieve minimal attack burden with reduced disease and treatment burden. CONCLUSION: This consensus report builds on existing guidelines by expanding the assessment of disease burden and QoL measures for patients with HAE.

Economic costs associated with acute attacks and long-term management of hereditary angioedema.

BACKGROUND: Hereditary angioedema (HAE) is a rare autosomal dominant disorder characterized by recurrent acute attacks of swelling of the larynx, abdomen, and periphery. OBJECTIVE: To assess the economic burden associated with acute attacks and long-term management of HAE. METHODS: Burden was assessed via a Web-based survey of HAE patients (> or = 18 years old) that solicited information on attack characterization, short-term treatment, long-term disease management, impact on work, and patient costs. A standardized instrument, the Work Productivity and Activity Impairment questionnaire, was included to assess impact on work productivity. Standard medical costs and US average wage costs were assigned to survey items to assess direct medical and indirect costs, respectively. RESULTS: Total annual per-patient costs are estimated at $42,000 for the average HAE patient, with costs totaling $14,000 for patients with mild attacks, $27,000 for patients with moderate attacks, and $96,000 for patients with severe attacks. Hospital costs account for 67% of direct medical costs. Respondents reported high rates of missed work, lost productivity, and lost income, contributing to indirect costs totaling $16,000 annually for the average patient. Almost all costs increase with disease severity, although the distribution varies with severity: indirect costs account for 75% of costs for patients with mild attacks, whereas emergency department and hospital costs account for 68% of costs for patients with severe attacks. CONCLUSIONS: HAE results in considerable economic burden to patients, payers, and society in terms of direct medical and indirect costs and compounds the substantial humanistic burdens, which will be reported separately.

Increased activity of coagulation factor XII (Hageman factor) causes hereditary angioedema type III.

Hereditary angioedema (HAE) is characterized clinically by recurrent acute skin swelling, abdominal pain, and potentially life-threatening laryngeal edema. Three forms of HAE have been described. The classic forms, HAE types I and II, occur as a consequence of mutations in the C1-inhibitor gene. In contrast to HAE types I and II, HAE type III has been observed exclusively in women, where it appears to be correlated with conditions of high estrogen levels--for example, pregnancy or the use of oral contraceptives. A recent report proposed two missense mutations (c.1032C-->A and c.1032C-->G) in F12, the gene encoding human coagulation factor XII (FXII, or Hageman factor) as a possible cause of HAE type III. Here, we report the occurrence of the c.1032C-->A (p.Thr328Lys) mutation in an HAE type III-affected family of French origin. Investigation of the F12 gene in a large German family did not reveal a coding mutation. Haplotype analysis with use of microsatellite markers is compatible with locus heterogeneity in HAE type III. To shed more light on the pathogenic relevance of the HAE type III-associated p.Thr328Lys mutation, we compared FXII activity and plasma levels in patients carrying the mutation with that of healthy control individuals. Our data strongly suggest that p.Thr328Lys is a gain-of-function mutation that markedly increases FXII amidolytic activity but that does not alter FXII plasma levels. We conclude that enhanced FXII enzymatic plasma activity in female mutation carriers leads to enhanced kinin production, which results in angioedema. Transcription of F12 is positively regulated by estrogens, which may explain why only women are affected with HAE type III. The results of our study represent an important step toward an understanding of the molecular processes involved in HAE type III and provide diagnostic and possibly new therapeutic opportunities.