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Background: Clinical trials investigating drugs for the acute treatment of hereditary angioedema attacks have assessed many different outcomes. This heterogeneity limits the comparability of trial results and may lead to selective outcome reporting bias and a high burden on trial participants., Objective: To achieve consensus on a core outcome set composed of key outcomes that ideally should be used in all clinical efficacy trials involving the acute treatment of hereditary angioedema attacks., Methods: We conducted a Delphi consensus study involving all relevant parties: patients with hereditary angioedema, hereditary angioedema expert clinicians and clinical researchers, pharmaceutical companies, and regulatory bodies. Two Internet-based survey rounds were conducted. In round 1, panelists indicated the importance of individual outcomes used in clinical trials on a 9-point Likert scale. Based on these results, a core outcome set was developed and voted on by panelists in round 2., Results: A total of 58 worldwide panelists completed both rounds. The first round demonstrated high importance scores and substantial agreement among the panelists. In the second round, a consensus of 90% or greater was achieved on a core outcome set consisting of five key outcomes: change in overall symptom severity at one predetermined time point between 15 minutes and 4 hours after treatment, time to end of progression of all symptoms, the need for rescue medication during the entire attack, impairment of daily activities, and treatment satisfaction., Conclusions: This international study obtained a high level of consensus on a core outcome set for the acute treatment of hereditary angioedema attacks, consisting of five key outcomes., (Crown Copyright © 2024. Published by Elsevier Inc. All rights reserved.)

Background: Hereditary angioedema (HAE) due to C1-inhibitor (C1-INH) deficiency is characterized by unpredictable recurrent episodes of swelling affecting the skin and the mucosa tissues, including gastrointestinal tract and/or oropharyngeal-laryngeal mucosae. Long-term prophylaxis (LTP) is used to prevent attacks., Objective: Because C1-INH plays a pivotal role in several biological pathways, we investigated the possible association of comorbidities with C1-INH deficiency and the use of LTP with attenuated androgens (AA) or tranexamic acid (TXA)., Methods: This retrospective cohort study involved adult patients with HAE referred to Milan and Padua angioedema centers in the period 1979-2021. A qualitative comparison was performed to analyze comorbidities versus general population. The incidence of comorbidities was evaluated during LTP with AA or TXA versus patients without LTP., Results: A total of 446 patients were studied. A greater prevalence among patients was found for heart diseases (9.6% vs 4.8%), acute myocardial infarction (5.6% vs 1.4%), hepatitis C virus infection (10.5% vs 2.5%), and appendectomy (15.9% vs 4.3%). In patients taking AA, a greater incidence was found for hypertension (22.8% vs 10.8%; odds ratio [OR]: 2.02), hypercholesterolemia (19.5% vs 5.3%; OR: 3.97), diabetes mellitus (5% vs 1.4%; OR: 3.21), hepatic angioma (4.4% vs 0.7%; OR: 8.35), and focal nodular hyperplasia (2.5% vs 0.4%; OR: 6.9). No association between TXA and comorbidities was found., Conclusion: In this large patient population with a rare disease followed for up to a 43-year period, we found a greater prevalence of comorbidities hitherto unreported in the literature and an association between comorbidities and LTP with AA., (Copyright © 2024. Published by Elsevier Inc.)

Hereditary angioedema (HAE) is typically caused by a deficiency of the protease inhibitor C1 inhibitor (C1INH). The absence of C1INH activity on plasma kallikrein and factor XIIa leads to overproduction of the vasoactive peptide bradykinin, with resulting angioedema. As the primary site of C1INH and prekallikrein production, the liver is recognized as an important therapeutic target in HAE, leading to the development of hepatic-focused treatment strategies such as GalNAc-conjugated antisense technology and gene modification. This report reviews currently available data on hepatic-focused interventions for HAE that have advanced into human trials. Donidalorsen is an investigational GalNAc 3 -conjugated antisense oligonucleotide that binds to prekallikrein mRNA in the liver and reduces the expression of prekallikrein. Phase 2 data with subcutaneous donidalorsen demonstrated a significant reduction in HAE attack rate compared with placebo. Phase 3 trials are underway. ADX-324 is a GalNAc 3 -conjugated short-interfering RNA being investigated in HAE. BMN 331 is an investigational AAV5-based gene therapy vector that expresses wild-type human C1INH and is targeted to hepatocytes. A single intravenous dose of BMN 331 is intended to replace the defective SERPING1 gene and enable patients to produce functional C1INH. A first-in-human phase 1/2 study is ongoing with BMN 331. NTLA-2002 is an investigational in vivo clustered regularly interspaced short palindromic repeats/Cas9-based therapy designed to knock out the prekallikrein-coding KLKB1 gene in hepatocytes; a phase 1/2 study is ongoing. Findings from these and other ongoing studies are highly anticipated with the expectation of expanding the array of treatment options in HAE., (Copyright © 2024 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Symptoms of hereditary angioedema (HAE) often first occur during childhood, and HAE attacks in children can be severe and substantially affect health-related quality of life (HRQoL). However, there are no approved long-term prophylaxis treatments for children aged less than 6 years., Objective: The SPRING Study (NCT04070326) evaluated the safety, pharmacokinetics, and efficacy of lanadelumab and HRQoL in patients aged 2 to less than 12 years., Methods: Over 52 weeks of treatment, patients aged 2 to less than 6 years received lanadelumab 150 mg every 4 weeks (Q4W) and patients aged 6 to less than 12 years received 150 mg every 2 weeks (Q2W) but could switch to Q4W if they were attack-free for 26 weeks., Results: We enrolled 21 patients (aged 2 to less than 6 years: n = 4; aged 6 to less than 12 years: n = 17), 20 of whom completed the study. There were no reported serious treatment-emergent adverse events or discontinuations resulting from such events. Treatment-emergent adverse events were reported for 17 patients (81.0%). The most common TEAE was injection site pain. Overall systemic exposure was comparable for both age groups. The mean (SD) attack rate during treatment decreased by 94.8% from baseline (1.84 [1.53] to 0.08 [0.17] attacks/mo), and 16 (76.2%) patients were attack-free. The attack rate reduction in both age groups was similar during the first 26-week fixed-dosing treatment. Seven patients switched from Q2W to Q4W and remained attack-free. A large, clinically meaningful increase in the Pediatric Quality of Life Inventory Generic Core Scale Total Score and a large increase in the Pediatric Quality of Life Inventory Generic Core Scale-Family Impact Module Total Score from baseline to end of study (better HRQoL) were observed., Conclusions: Findings support safety, efficacy, and improved HRQoL with lanadelumab 150 mg Q2W and Q4W regimens for the prevention of HAE attacks in patients aged 2 to less than 12 years., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Hereditary angioedema (HAE) is a rare and potentially fatal genetic disease associated with recurrent and unpredictable episodes of angioedema. Although modern therapies have dramatically increased quality of life, insurance changes, delays, and denials are becoming more common., Objective: To examine the impact of insurance delays and denials on patient health and well-being., Methods: A total of 20 patients with HAE (type 1 and 2) who recently experienced insurance delays or denials completed an online survey, and 19 participated in a follow-up focus group. The survey and focus group addressed the impact of insurance challenges on the use of health care services, work/school attendance, and anxiety. Three independent reviewers coded each focus group transcript using a thematic saturation approach., Results: A total of 70% of participants reported an increased frequency of angioedema attacks resulting from insurance delays or denials. More than 50% missed work/school days because of increased attacks, and 90% reported greater anxiety. Twenty-five percent of respondents reported more urgent care or emergency department visits. In focus groups, participants identified specific ways that losing access to medication had a negative impact on their health, family, and work/school life. Insufficient notification of health insurance policy changes and the time and effort required to regain access to medications compounded patients' frustration and anxiety., Conclusion: Insurance delays and denials have significant impacts on individuals with HAE including (1) increased urgent care and emergency department visits, (2) missed work/school days, (3) higher levels of anxiety, and (4) a negative impact on family life., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

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., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Detailed demographic data on people with hereditary angioedema (HAE) and acquired C1 inhibitor deficiency in the United Kingdom are relatively limited. Better demographic data would be beneficial in planning service provision, identifying areas of improvement, and improving care., Objective: To obtain more accurate data on the demographics of HAE and acquired C1 inhibitor deficiency in the United Kingdom, including treatment modalities and services available to patients., Methods: A survey was distributed to all centers in the United Kingdom that look after patients with HAE and acquired C1 inhibitor deficiency to collect these data., Results: The survey identified 1152 patients with HAE-1/2 (58% female and 92% type 1), 22 patients with HAE with normal C1 inhibitor, and 91 patients with acquired C1 inhibitor deficiency. Data were provided by 37 centers across the United Kingdom. This gives a minimum prevalence of 1:59,000 for HAE-1/2 and 1:734,000 for acquired C1 inhibitor deficiency in the United Kingdom. A total of 45% of patients with HAE were on long-term prophylaxis (LTP) with the most used medication being danazol (55% of all patients on LTP). Eighty-two percent of patients with HAE had a home supply of acute treatment with C1 inhibitor or icatibant. A total of 45% of patients had a supply of icatibant and 56% had a supply of C1 inhibitor at home., Conclusions: Data obtained from the survey provide useful information about the demographics and treatment modalities used in HAE and acquired C1 inhibitor deficiency in the United Kingdom. These data are useful for planning service provision and improving services for these patients., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Hereditary angioedema (HAE) is a rare disease characterized by sudden and often unprovoked episodes of swelling that can be potentially life-threatening when it involves the upper airway. The treatment options for both acute episodes of HAE and LTP, used to minimize the frequency and severity of angioedema attacks, were limited historically to very few options, had considerable side effects, and/or had considerable burden of treatment. Fortunately, through the elucidation of the pathophysiology of HAE, the development of newer targeted therapies has been possible both for acute therapy and long-term prophylaxis and even more are on the horizon. Because of the rapid development of these therapies, it can be challenging for clinicians to keep abreast of newer and developing treatments for HAE. This review article will outline the current and potential future treatments for HAE. It will also highlight important considerations when treating special HAE patient populations including women and pediatric patients., (Copyright © 2023 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: According to the current treatment guidelines, the goals of treatment of patients with hereditary angioedema (HAE) are to achieve total control of the disease and to normalize patients' lives., Objective: This study aims to establish the entire burden of HAE comprising disease control, treatment satisfaction, reductions in quality of life, and societal costs., Methods: Adult patients with HAE under treatment at the Dutch national center of reference completed a cross-sectional survey in 2021. The survey consisted of different questionnaires: angioedema-specific questionnaires (4-week Angioedema Activity Score and Angioedema Control Test), quality of life questionnaires (Angioedema Quality of Life [AE-QoL] questionnaire and EQ-5D-5L), the Treatment Satisfaction Questionnaire for Medication (TSQM), and societal costs questionnaires (iMTA Medical Consumption Questionnaire and iMTA Productivity Cost Questionnaire)., Results: The response rate was 78% (69 of 88). The entire sample had a mean Angioedema Activity Score of 16.61, and 36% of participants had poorly controlled disease as expressed by the Angioedema Control Test. The mean quality of life in the entire sample was 30.99 as expressed by the AE-QoL and 0.873 as expressed by the EQ-5D-5L utility value. Utilities dropped by 0.320 points during an angioedema attack. TSQM scores ranged from 66.67 to 75.00 across its 4 domains. On average, total costs per year incurred €22,764, predominantly existing of HAE-medication costs. Total costs showed substantial variation between patients., Conclusions: This study describes the entire burden of HAE among Dutch patients comprising disease control, quality of life, treatment satisfaction, and societal costs. These results can inform cost-effectiveness analyses that can aid reimbursement decisions for HAE treatments., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: To understand the impact and burden of disease experienced by patients with hereditary angioedema (HAE)., Objective: To determine whether the use of short message service (SMS) to communicate with patients with HAE facilitates the collection of attack rate, medication use, and quality of life measurements., Methods: Patients aged 12 years and older with doctor-confirmed HAE C1-inhibitor deficiency types I and II were invited to participate. We devised a novel method for monitoring attacks by using questions weekly via SMS to gain a more accurate picture of the burden of HAE in Australian patients in real time., Results: A total of 2,648 weekly SMS messages were sent to 47 participants; 1,892 responses were received (71%). Participants reported 463 attacks across all treatment groups. Sixty percent of attacks were treated. Icatibant and C1-inhibitor concentrate were administered IV for 210 and 67 attacks, respectively. Of the 463 recorded attacks, 23 necessitated presentation to the hospital (5%), predominantly for facial and/or throat swelling. Several participants reported attacks (n = 186), which they chose not to treat. Most of those attacks were rated mildly severe. Twenty-one participants reported lost days owing to HAE attacks (44.7%). Fifty-eight attacks (17%) resulted in time away from work or school, equating to a total of 85.5 days lost., Conclusions: This study was a first of its kind, real-world, prospective, observational study of Australian patients living with HAE. Despite the availability of effective on-demand therapies, HAE remains burdensome. Wider access to safe and effective prophylactic therapies is needed for patients living with HAE., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Angioedema is generally readily recognizable clinically and is characterized by localized nonpitting edema involving subcutaneous, submucosal, or deep dermal tissue caused by increased vascular permeability and extravasation of intravascular fluid. It can occur via a variety of mechanisms. A number of clinical conditions (masqueraders) are occasionally mistaken for angioedema. Clinical classification of the various angioedema forms begins with noting the presence or absence of concurrent urticaria or wheals. Pathogenesis can be considered through two broad categories: mast cell-mediated with release of vasoactive mediators causing angioedema usually associated with urticaria or in the context of an anaphylactic reaction; and bradykinin (BK)-driven, in which increased vascular permeability is mediated by BK. BK-mediated angioedema does not occur with urticaria, nor does it respond to antiallergic medications. The various forms of hereditary angioedema are included in this category, requiring specific tests of C4 and C1 inhibitor level and function to confirm the diagnosis. Angiotensin converting enzyme inhibitors, which impair the degradation of BK, account for up to a third of all patients with angioedema presenting to the emergency department. Finally, angioedema may occur by yet unknown mechanisms; under this circumstance, it is difficult to manage., (Crown Copyright © 2023. Published by Elsevier Inc. All rights reserved.)

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., (Copyright © 2022 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

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., (Copyright © 2022 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Hereditary angioedema (HAE) is known for mortality when it is not treated properly. Many advances have occurred over the past decades that affected patients' lives. However, not all patient populations have access to the same diagnosis and treatment resources., Objective: To evaluate mortality from HAE in a large cohort in a reference center in Brazil. Furthermore, the research intended to describe patients' life span, the asphyxia evolution, and factors related to the fatal outcome., Methods: A cohort of 433 patients from 46 families was evaluated in this prospective and retrospective study. Families were organized in clusters and were given a verbal autopsy to arrange data collection for the deaths and analyze symptoms during life. Causes of death were classified as deaths from laryngeal edema (LE) or other causes., Results: Of 433 patients evaluated, 254 were not given the diagnosis of HAE. A total of 75 fatal events were evaluated. Only 10 of 75 patients were given the diagnosis of HAE before death, and the HAE diagnosis was made after death in 65 of 75 patients using verbal autopsy. The final cause of death after the investigation was asphyxiation owing to LE in 39 of 75 (52%) and deaths owing to other causes in 36 of 75 (48%). Ten deaths had occurred in the past decade. Time from onset of symptoms to seeking medical assistance was a median of 4 hours, and the time to death was a median of 8 hours. Three patients received fresh-frozen plasma and none received medications specific to HAE attacks. Throat pain or discomfort was the most common symptom, experienced by 71.8% of patients. The most common mistaken diagnosis at the original death certificate was allergy or anaphylaxis. The life span of patients who died of LE was reduced by 20 years compared with those who died of other causes., Conclusions: Hereditary angioedema remains a threat to life in the studied population. The large number of patients who do not receive a diagnosis makes the situation even more severe and is responsible for most deaths. Death analyses add knowledge to an understanding of the diseases and their impact on patients' lives, improving the targeting of public health efforts., (Copyright © 2022 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Hereditary angioedema (HAE) may be caused by a genetic deficiency of functional C1 inhibitor (C1-INH) or linked with mutations in the F12, PLG, and other genes in combination with normal C1-INH (HAEnCI). Although the types of hereditary angioedema due to deficiency of functional C1 inhibitor and HAEnCI are autosomal dominant inherited, there is the impression that in the types of HAEnCI more females carry disease-linked mutations., Objective: The aim of this study was to analyze the passing on of the HAE-specific mutations to the next generations in families with various types of HAE., Methods: Methods comprised pedigree analysis, Sanger sequencing analysis, biochemical analysis of parameters of the kallikrein-kinin system, and statistical analysis of the results. We analyzed a total of 1494 offspring of individuals carrying an HAE-linked mutation., Results: In HAE, less male and more female offspring of mutation carriers than expected for autosomal dominant inheritance inherited the familial mutation. In addition, there were less male offspring than expected in HAEnCI. This was independent of paternal or maternal inheritance., Conclusion: We conclude that there is a sex- and mutation-dependent selection during early embryogenesis, possible around the time of implantation, favoring male wild-type and female mutant embryos. It also appears that 20% to 25% of male embryos carrying the HAE mutation are lost specific in HAEnCI. These findings point out that there is a potentially important role of the kallikrein-kinin system during early embryonic development., (Copyright © 2021 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Hereditary angioedema (HAE) is a rare, chronic, genetic disease that presents with nonpruritic angioedema of the face, extremities, airway (can be life-threatening), genitourinary system, and abdomen. These symptoms can significantly impair daily activities. Hereditary angioedema is classified into HAE owing to a deficiency of functional C1INH (HAE-C1INH) or HAE with normal C1INH (HAE-nl-C1INH). Both type I and II HAE-C1INH result from inherited or spontaneous mutations in the SERPING1 gene, which encodes for C1INH. These mutations result in C1INH dysfunction, leading to uncontrolled plasma kallikrein activity with excessive bradykinin production. Bradykinin receptor activation leads to vasodilation, increased vascular permeability, and smooth muscle contractions, resulting in submucosal angioedema through fluid extravasation. Hereditary angioedema nl-C1INH is caused by either a known or unknown genetic mutation. The underlying mechanism of HAE-nl-C1INH is less well understood but is thought to be related to bradykinin signaling. Plasma kallikrein inhibitors have been developed to inhibit the kallikrein-kinin pathway to prevent (prophylactic) and treat on-demand (acute) HAE attacks. Several of these medications are delivered through subcutaneous or intravenous injection, although new and emerging therapies include oral formulations. This article provides a historical review and describes the evolving landscape of available kallikrein inhibitors to treat HAE-C1INH., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Hereditary angioedema (HAE) affects all races and both sexes equally. Minority patients are underrepresented in clinical trials and may be at risk for additional disease burden., Objectives: To examine racial and ethnic disparities in the research and care of patients with HAE., Methods: We conducted a retrospective population-based study using TriNetX Diamond Network. International Classification of Diseases, 10th Revision, Current Procedural Terminology, and RxNorm codes identified patients with HAE. The proportions of White, Black, and Hispanic patients with HAE were contrasted with racial and ethnic distributions of patients with HAE in clinical trials. Lifetime prevalence of mental health disorders and HAE treatments was contrasted among different racial and ethnic groups., Results: A population-based search identified 2122 patients with HAE. The prevalence of HAE among Black patients (1.64/100,000 patients) mirrored that of White patients (1.47/100,000 patients), whereas there was a lower HAE prevalence among Hispanic patients (0.80/100,000 patients). The demographics of the 1274 patients with HAE included in phase 2/3 clinical trials differed significantly from population-based data with overrepresentation of White patients (89.9% vs 77.9%) and underrepresentation of Black patients (3.8% vs 13.6%) and Hispanic patients (1.3% vs 8.1%). Across the different racial and ethnic groups of patients with HAE, the prevalence of mental health disorders was comparatively higher than among patients without HAE. Whereas depression was equally prevalent across the different HAE racial and ethnic groups, anxiety was more prevalent among White patients., Conclusions: Clinical trials for Food and Drug Administration-approved HAE medications underrepresent minority patients. Hereditary angioedema remains underdiagnosed in Hispanic patients. Other than a lower prevalence of anxiety disorders among Black patients relative to White patients, the mental health impact of HAE is equally distributed across the different racial and ethnic groups., (Copyright © 2021 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Lanadelumab has been available in Germany for the prophylactic treatment of hereditary angioedema since February 2019., Objective: To investigate real-life treatment outcome of lanadelumab and gain practical experience in adapting the therapy to individual patients., Methods: The study included 34 patients. In 24 patients with hereditary angioedema and 4 patients with angioedema due to acquired C1-inhibitor deficiency, the previous treatment was switched to lanadelumab. In 6 patients with hereditary angioedema, lanadelumab from the open-label Hereditary Angioedema Long-term Prophylaxis study was continued in regular care. During the transition, patients were monitored using the angioedema control test and the angioedema quality of life questionnaire. At the time at which patients became symptom-free, the dosage interval was increased gradually (+3 days)., Results: On average, the angioedema control test values improved from 7.5 (poorly controlled disease) to 14.9 (well-controlled disease), and all patients showed adequate disease control. All treated patients, except 1 outlier, scored angioedema quality of life questionnaire values representing only a slight reduction in quality of life (mean, 14 points). At the time point of data collection, 9 patients used an average fixed injection interval of 30 days. Twenty-two patients were symptom-free from the beginning of the treatment phase and intended to extend their injection interval from 30 to 32.5 days (median). We recommended reducing the initial dosing interval from 24 to 21 days (median) to 3 patients because of intermediately occurring symptoms., Conclusions: Gradual extension of injection intervals of lanadelumab presented in this study can minimize the burden of therapy without losing efficacy., (Copyright © 2021 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Chronic urticaria and angioedema are diseases often managed by Allergy and Immunology specialists. Recent international guidelines have outlined a stepwise approach to management of patients using dose escalation of second-generation antihistamines followed by use of omalizumab and finally cyclosporine in more refractory cases. In select patients (those with refractory chronic urticaria), nonbiologic alternative medications with anti-inflammatory or immunosuppressant activity may be considered. Angioedema without wheals may have several different pathophysiologic mechanisms. Optimal management of mast cell-mediated angioedema is less clear but is often managed similar to chronic spontaneous urticaria. Drug-induced angioedema due to angiotensin-converting enzyme inhibitors is a common cause of angioedema in the emergency department. Although bradykinin is thought to be a primary mediator for this type of angioedema, studies of targeted therapies have been generally disappointing. In contrast, several targeted therapies have been proven successful using acute and preventive approaches for management of hereditary angioedema. Further developments, including novel biologics, novel oral therapies, and gene therapy approaches, may hopefully continue to broaden therapeutic options to ensure optimal individual management of patients with hereditary angioedema., (Copyright © 2021 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Berotralstat (BCX7353) is a recently approved, oral, once-daily kallikrein inhibitor for hereditary angioedema (HAE) prophylaxis. In the APeX-2 trial, berotralstat reduced HAE attack rates over 24 weeks, with a favorable safety and tolerability profile., Objective: Evaluate berotralstat safety, tolerability, and effectiveness over 48 weeks., Methods: APeX-2 is a phase 3, parallel-group, multicenter trial (NCT03485911) in patients with HAE due to C1 esterase inhibitor deficiency. Part 1 was double-blind and placebo-controlled, with patients randomized to 24 weeks of berotralstat 150 mg, 110 mg, or placebo. In part 2, patients continued berotralstat the same dose or, if initially randomized to placebo, were rerandomized to berotralstat 150 mg or 110 mg through weeks 24 to 48. The primary end point was safety and tolerability., Results: One hundred eight patients received 1 or more doses of berotralstat in part 2. Treatment-emergent adverse events (TEAEs) occurred in 30 of 39 patients (77%) in the placebo group during part 1, and 25 of 34 patients (74%) re-randomized from placebo to berotralstat 110 mg or 150 mg in part 2, with drug-related TEAEs in 13 of 39 (33%), and 11 of 34 (32%) in the same groups. Most TEAEs were mild or moderate, with no serious drug-related TEAEs. The most common TEAEs were upper respiratory tract infections, abdominal pain, diarrhea, and vomiting. Mean (±standard error of the mean) monthly attack rates at baseline and week 48 were 3.06 (±0.25) and 1.06 (±0.25) in the berotralstat 150mg 48-week group and 2.97 (±0.21) and 1.35 (±0.33) in the berotralstat 110mg 48-week group., Conclusions: The safety, tolerability, and effectiveness of berotralstat were maintained over 48 weeks of treatment., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

The evolution in the knowledge of rare genetic diseases such as hereditary angioedema (HAE) has increased at a parallel pace with the development of new molecular tools. The deficiency of C1 inhibitor (C1-INH) has been recognized as the main cause of HAE (HAE-C1-INH) since the 1960s, but the discovery of the wide spectrum of mutations affecting the C1-INH gene (SERPING1) was possible only from the late 1980s, when Sanger sequencing became available and more accessible worldwide. Nevertheless, the involvement of other genes in HAE was discovered only in 2006 with the description of mutations in the F12 gene in patients with HAE and normal C1-INH. In the last 3 years, advanced next-generation sequencing techniques allowed the identification of mutations in 5 new genes being associated with HAE and normal C1-INH: ANGPT1 (angiopoietin-1), PLG (plasminogen), KNG1 (kininogen), MYOF (myoferlin), and HS3ST6 (heparan sulfate-glucosamine 3-O-sulfotransferase 6). The knowledge provided by the new era of genomic studies was pivotal in the discovery of mutations in new genes responsible for this complex pathogenesis. Genomics advances promise a better understanding of unknown mechanisms leading to HAE, the establishment of new molecular targets for novel therapeutic agents, and personalized treatment., (Copyright © 2021 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Primary angioedema (PA) is a complex disorder, presenting multiple hereditary (hereditary angioedema) and acquired subtypes (acquired angioedema). Despite a very similar clinical presentation among subtypes, the differential diagnosis is limited by the difficulty to identify bradykinin-mediated PA and the lack of specific biomarkers., Objectives: To report the clinical and genetic features of Brazilian patients with PA., Methods: Brazilian patients referred from 50 centers were diagnosed on the basis of clinical symptoms, C1 inhibitor (C1-INH) and C4 plasma measurements, and DNA sequencing of genes associated with hereditary angioedema., Results: We characterized 92 patients with acquired angioedema and 425 with HAE: 125 with C1-INH deficiency, 180 with F12 mutations, and 120 of unknown cause. Thirty-one different mutations were identified in SERPING1 and 2 in F12, in addition to 2 mutations of uncertain significance in the ANGPT1 gene. The molecular diagnosis was decisive for 34 patients with HAE without family history, and for 39% of patients with inconsistent biochemical measurements. The median delay in diagnosis was 10 years, with a maximum of 18 years for HAE with C1-INH deficiency. Androgens and tranexamic acid were the most used drugs for long-term prophylaxis in all the PA subtypes, and they were used on demand by 15% of patients. Only 10% of patients reported the use of specific medication for HAE during attacks., Conclusions: Our analysis exposes a broad picture of PA diagnosis and management in a developing country. Complement measurements presented considerable inconsistencies, increasing the diagnosis delay, while patients with PA with normal C1-INH remain with an inaccurate diagnosis and unspecific treatment., (Copyright © 2020 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Angiotensin-converting enzyme inhibitors may cause angioedema. Currently, no laboratory method is available for identifying acquired angioedema related to angiotensin-converting enzyme inhibitors. However, establishing the diagnosis is possible from the medical history and the preexisting angiotensin-converting enzyme inhibitor therapy, as well as by excluding other angioedema types., Objective: To evaluate the results of complement testing in patients experiencing angioedema while taking angiotensin-converting enzyme inhibitors., Methods: Between 2005 and 2019, a total of 149 patients taking angiotensin-converting enzyme inhibitors were referred to our Angioedema Center for the diagnostic evaluation of recurrent angioedema episodes. Complement measurement was performed on these patients., Results: The mean age of the 149 patients treated with angiotensin-converting enzyme inhibitors at the onset of the index angioedema episode was 55.8 years. The mean interval between the introduction of angiotensin-converting enzyme inhibitor therapy and the occurrence of the initial symptoms of angioedema was 43 months. The most commonly used angiotensin-converting enzyme inhibitor was perindopril (32.9% of the patients). The initial angioedema episode involved the face in 50.3%, the lips in 40.9%, and the tongue in 33.5% of the patients. Angiotensin-converting enzyme inhibitors were discontinued in all 149 patients, and at the same time, a complement test was performed. The complement tests confirmed hereditary angioedema with C1-inhibitor deficiency in 2 patients and an additional 12 family members. Acquired angioedema with C1-inhibitor deficiency was found in 3 patients., Conclusions: Excluding hereditary angioedema and acquired angioedema with C1-inhibitor deficiency is indispensable for establishing the diagnosis of acquired angioedema related to angiotensin-converting enzyme inhibitors., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Scientific and clinical progress together with the development of effective novel therapeutic options has engendered multiple important changes in the diagnosis and management of hereditary angioedema (HAE). We now update and extend the 2013 United States Hereditary Angioedema Association Medical Advisory Board guidelines for the treatment and management of HAE. The guidelines are based on a comprehensive literature review with recommendations indicating both the strength of our recommendation and the quality of the underlying evidence. Guidelines are provided regarding the classification, diagnosis, on-demand treatment, prophylactic treatment, special considerations for women and children, development of a comprehensive management and monitoring plan, and assessment of burden of illness for both HAE due to C1 inhibitor deficiency and HAE with normal C1 inhibitor. Advances in HAE treatment now allow the development of management plans that can help many patients with HAE lead a normal life. Achieving this goal requires that physicians be familiar with the diagnostic and therapeutic transformations that have occurred in recent years., (Published by Elsevier Inc.)

Background: Hereditary angioedema (HAE) symptoms may be triggered by dental procedures, thereby complicating dental care in individuals affected by the condition., Objective: This study investigated the self-perceived dental care needs, perceived susceptibility to acute angioedema (AE) attacks after dental procedures, and dental care behavior of patients with HAE., Methods: A self-administered semistructured web-based questionnaire was distributed to 250 adult patients with HAE (type 1 or 2; 88% type 1) and 256 matched non-HAE controls. Data were analyzed using stratified χ 2 tests, logistic regression, and classification trees., Results: A total of 46.4% of HAE versus 55.5% of control patients had dental visits within 6 months (P = .04). Dental insurance was a barrier to seeking routine dental visits among both groups. However, significantly fewer patients with HAE had routine dental visits within 6 months despite having dental insurance compared with control patients (48% vs 60%, P = .01). Within the HAE group, a significantly greater number of patients with dental visits at intervals greater than 6 months had a history of recurrent postprocedural AE attacks (odds ratio [OR]: 3.9 [1.7, 8.8], P = .0005) and used antibacterial toothpaste more frequently than those without recurrent AE attacks (OR: 4.7 [1.5, 15.4], P = .005)., Conclusions: These data support the hypothesis that patients with HAE who are predisposed to having AE episodes in response to medical or physical trauma visit the dentist less and engage in specific oral hygiene practices more frequently than matched control patients and patients with HAE who reported that they were less likely to swell after a dental procedure., (Copyright © 2020 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Plasma-derived C1-inhibitor (pdC1-INH) is a first-line therapy for hereditary angioedema (HAE) with C1-inhibitor deficiency (C1-INH-HAE) in pediatric patients., Objective: We intended to study the clinical characteristics and safety of treatment with pdC1-INH in this population., Methods: In the prospective, long-term survey, real-world data on pdC1-INH (Berinert, CSL Behring) use in pediatric patients, diagnosed and followed up at our Angioedema Reference Center, were analyzed for the period from 1986 to 2018., Results: A total of 70 pediatric patients (31 boys and 39 girls) experienced a total of 3009 HAE attacks. The most common location of HAE attacks was subcutaneous. HAE attacks of any location were more frequent in girls versus boys, except for genital edema. Among the 70 patients, 37 received pdC1-INH for 456 HAE attacks, or as prophylaxis (69 vials). On average, 14.2 vials were administered per patient. The distribution of pdC1-INH use in the different age groups was as follows: no use (0-1 years), 0.11 vials/year (1-3 years), 0.7 vials/year (3-6 years), 1.26 vials/year (6-12 years), and 1.28 vials/year (12-18 years). No systemic allergic reactions, viral transmission, development of anti-C1-INH antibodies, or thromboembolic events occurred in relation to treatment with this drug., Conclusion: We confirmed that the clinical manifestations and the use of pdC1-INH are different in the various age groups of pediatric patients with C1-INH-HAE. Our long-term survey shows that the use of pdC1-INH is safe in this patient population., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Consensus guidelines recommend plasma-derived C1 inhibitor (C1-INH) as first-line treatment in pregnant women with hereditary angioedema (HAE). We conducted a systematic review of the literature that describes experience with plasma-derived C1-INH during pregnancy. A literature search of PubMed was conducted in November 2018 using variants of "hereditary angioedema" and "pregnancy." English language articles that presented original data about the use of plasma-derived C1-INH during pregnancy were selected for data extraction. The search returned 253 unique records, of which 40 described the use of C1-INH during pregnancy (91 patients, 136 pregnancies). When the number of doses was reported, a total of 1562 doses were administered ranging from 500 to 3000 IU. Infusions were administered during all 3 trimesters and were most commonly administered during the third trimester. Overall, 1,490,500 IU of plasma-derived C1-INH were administered during pregnancy. Of the 128 fetuses for which outcomes were reported, 3 (2%) resulted in spontaneous abortion, 1 (1%) was stillborn, and 1 (1%) was a vanishing twin. Use of plasma-derived C1-INH in women with HAE during pregnancy has been widely reported in the scientific literature and has a favorable safety profile, supporting treatment guideline recommendations., (Copyright © 2020. Published by Elsevier Inc.)

Hereditary angioedema (HAE) is caused by deficiency or dysfunction in the C1 inhibitor (C1-INH) protein. C1-INH replacement therapy is used to treat patients with HAE to restore the missing or dysfunctional protein. In vitro studies showed that C1-INH inhibits prekallikrein activation and bradykinin formation in a dose-dependent manner when added to the plasma of patients with HAE. HAE is highly variable in clinical presentation, and early studies suggested that there was not a clear relationship between functional C1-INH levels and disease activity. Later, a threshold of approximately 40% functional C1-INH was identified, above which patients' risk of an attack was diminished. Long-term prophylaxis with plasma-derived C1-INH effectively reduces attack frequency and severity. Pharmacokinetic modeling shows that functional C1-INH levels are associated with the relative risk of having an attack. Subcutaneous administration of C1-INH results in consistently high levels of functional C1-INH activity, whereas intravenous administration results in periods of low trough functional C1-INH activity before the next scheduled dose, increasing the risk of an angioedema attack. These studies suggest that measurement of functional C1-INH activity may be useful as a biomarker of the risk of an attack in patients with HAE who are receiving long-term prophylaxis with plasma-derived C1-INH., (Copyright © 2019 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Hereditary angioedema (HAE) is becoming much more genetically complex than was initially considered. Thus, the role of HAE genetics is expanding beyond research laboratories, and the genotyping of subjects suffering from HAE has become diagnostically indispensable in clinical practice. The synthesis and interpretation of the clinical and biochemical analyses to facilitate appropriate genetic test selection has thus also become significantly more complex. With this in mind, an international multidisciplinary group of 14 experts in HAE genetics and disease management was convened in October 2018. The objective was to develop clear, actionable, evidence- and consensus-based statements aiming to facilitate the communication between physicians treating patients with HAE and clinical geneticists, and thus promote the effective use of genetics in the management of the disease. Eleven consensus statements were generated, encompassing considerations regarding the clinical indications for genotyping patients with angioedema, the methods of detection of HAE-causative variants, the variant pathogenicity curation, the genotyping of patients with HAE in the clinic, and genetic counseling. These statements are intended both to guide clinicians and to serve as a framework for future educational and further genetic testing developments as the field continues to evolve rapidly., (Copyright © 2019 American Academy of Allergy, Asthma & Immunology. All rights reserved.)

Background: Patients with hereditary angioedema (HAE) present to the emergency department (ED), where their symptoms are often incorrectly attributed to common allergic and gastrointestinal conditions, resulting in major delays in diagnosis and treatment., Objective: To develop a rapid triage HAE (Hereditary AngioEdema Rapid Triage [HAE-RT]) tool for ED settings., Methods: A mixed-methods approach was used in 3 phases: Phase 1: A literature review on the current management of patients with HAE in the ED. Phase 2: A Delphi study with HAE specialists (N = 9) and Patient Advocacy Group Members (N = 3) to reach consensus on the predictor variables (PVs) to be included in the HAE-RT tool. Phase 3: A retrospective chart review to assess the performance of the PVs for HAE., Results: The literature review informed the final list of PVs included in the HAE-RT prototype. Nine experts participated in the Delphi study. Of 8 identified HAE-specific PVs, 3 reached consensus: (1) absence of urticaria, (2) recurrent abdominal pain/swelling, and (3) lack of response to allergic-directed therapy. The retrospective study included 107 patients (N = 66 with HAE; N = 41 non-HAE). Patients with HAE were more likely to have a family history of HAE (71%; P < .0001), previous recurrent angioedema (96%; P < .002), and previous recurrent abdominal pain (77%; P < .0001), and only 6% responded to allergy treatments (P < .0001). The HAE-RT tool had 98% sensitivity and specificity., Conclusions: Expert consensus led to the identification and prioritization of variables that when incorporated into an HAE-RT tool were associated with a high level of sensitivity and specificity when applied to known patients., (Copyright © 2019 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: For the prevention of attacks of hereditary angioedema (HAE), the efficacy and safety of subcutaneous human C1-esterase inhibitor (C1-INH[SC]; HAEGARDA, CSL Behring) was established in the 16-week Clinical Study for Optimal Management of Preventing Angioedema with Low-Volume Subcutaneous C1-Inhibitor Replacement Therapy (COMPACT)., Objective: To assess the long-term safety, occurrence of angioedema attacks, and use of rescue medication with C1-INH(SC)., Methods: Open-label, randomized, parallel-arm extension of COMPACT across 11 countries. Patients with frequent angioedema attacks, either study treatment-naive or who had completed COMPACT, were randomly assigned (1:1) to 40 IU/kg or 60 IU/kg C1-INH(SC) twice per week, with conditional uptitration to optimize prophylaxis (ClinicalTrials.gov registration no. NCT02316353)., Results: A total of 126 patients with a monthly attack rate of 4.3 in 3 months before entry in COMPACT were enrolled and treated for a mean of 1.5 years; 44 patients (34.9%) had more than 2 years of exposure. Mean steady-state C1-INH functional activity increased to 66.6% with 60 IU/kg. Incidence of adverse events was low and similar in both dose groups (11.3 and 8.5 events per patient-year for 40 IU/kg and 60 IU/kg, respectively). For 40 IU/kg and 60 IU/kg, median annualized attack rates were 1.3 and 1.0, respectively, and median rescue medication use was 0.2 and 0.0 times per year, respectively. Of 23 patients receiving 60 IU/kg for more than 2 years, 19 (83%) were attack-free during months 25 to 30 of treatment., Conclusions: In patients with frequent HAE attacks, long-term replacement therapy with C1-INH(SC) is safe and exhibits a substantial and sustained prophylactic effect, with the vast majority of patients becoming free from debilitating disease symptoms., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Hereditary angioedema (HAE) with C1 inhibitor deficiency (C1-INH) is characterized by swelling of subcutaneous and/or submucosal tissues., Objective: To evaluate efficacy/safety of fixed-dose subcutaneous plasma-derived C1-INH (pdC1-INH) liquid for HAE attack prevention (NCT02584959)., Methods: Eligible patients were ≥12 years with ≥2 monthly attacks prescreening or pre-long-term prophylaxis. In a partial crossover design, 80% of patients were randomized to placebo or pdC1-INH liquid for 14 weeks and crossed over from active to placebo or vice versa for another 14 weeks. The remainder were randomized to pdC1-INH liquid for 28 weeks. The primary efficacy endpoint was normalized number of attacks (NNA) versus placebo. Key additional endpoints were the proportion of patients achieving NNA reduction ≥50%, attack severity, number of attack-free days, and safety., Results: Seventy-five patients were randomized and 58 (77%) completed the study. Mean age 41 years; 88% HAE type I. Least-squares means of NNA were reduced from 3.9 with placebo to 1.6 with pdC1-INH (from day 1; P < .0001). Most patients had ≥50% NNA reduction with pdC1-INH (from day 1, 78%). A total of 8.8% of placebo-treated patients were attack-free and 5.3%, 22.8%, and 63.2% had mild, moderate, and severe attacks, respectively; 37.5% of pdC1-INH-treated patients were attack-free and 8.9%, 26.8%, and 26.8% had mild, moderate, and severe attacks, respectively. Treatment-emergent adverse event rates were similar between groups (52% vs 56% for pdC1-INH crossover vs placebo, respectively)., Conclusions: Fixed-dose subcutaneous pdC1-INH liquid was superior to placebo in preventing HAE attacks and demonstrated a favorable safety profile., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Hereditary angioedema with C1-inhibitor deficiency (C1-INH-HAE) impairs health-related quality of life (HRQoL)., Objective: The objective of this study was to assess HRQoL outcomes in patients self-administering subcutaneous C1-INH (C1-INH[SC]; HAEGARDA) for routine prevention of HAE attacks., Methods: Post hoc analysis of data from the placebo-controlled, crossover phase III COMPACT study (Clinical Studies for Optimal Management of Preventing Angioedema with Low-Volume Subcutaneous C1-Inhibitor Replacement Therapy). Ninety patients with C1-INH-HAE were randomized to 1 of 4 treatment sequences: C1-INH(SC) 40 or 60 IU/kg twice weekly for 16 weeks, preceded or followed by 16 weeks of twice weekly placebo injections. All HAE attacks were treated with open-label on-demand treatment as necessary. HRQoL assessments at week 14 (last visit) included the European Quality of Life-5 Dimensions Questionnaire (EQ-5D-3L), the Hospital Anxiety and Depression Scale (HADS), the Work Productivity and Activity Impairment Questionnaire (WPAI), and the Treatment Satisfaction Questionnaire for Medication (TSQM)., Results: Compared with placebo (on-demand treatment alone), treatment with twice weekly C1-INH(SC) (both doses combined) was associated with better EQ-5D visual analog scale general health, less HADS anxiety, less WPAI presenteeism, work productivity loss, and activity impairment, and greater TSQM effectiveness and overall treatment satisfaction. More patients self-reported a "good/excellent" response during routine prevention with C1-INH(SC) compared with on-demand only (placebo prophylaxis) management. For each HRQoL measure, a greater proportion of patients had a clinically meaningful improvement during C1-INH(SC) treatment compared with placebo., Conclusions: In patients with frequent HAE attacks, a treatment strategy of routine prevention with self-administered twice weekly C1-INH(SC) had a greater impact on improving multiple HAE-related HRQoL impairments, most notably anxiety and work productivity, compared with on-demand treatment alone (placebo prophylaxis)., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Hereditary angioedema (HAE) with normal C1 inhibitor (C1-INH) is a rare condition with clinical features similar to those of HAE with C1-INH deficiency. Mutations in the F12 gene have been identified in subsets of patients with HAE with normal C1-INH, mostly within families of European descent., Objectives: Our aim was to describe clinical characteristics observed in Brazilians from 42 families with HAE and F12 gene mutations (FXII-HAE), and to compare these findings with those from other populations., Methods: We evaluated a group of 195 individuals, which included 102 patients clinically diagnosed with FXII-HAE and their 93 asymptomatic relatives., Results: Genetic analysis revealed that of the 195 subjects, 134 individuals (77.6% females) carried a pathogenic mutation in F12. The T328K substitution was found in 132 individuals, and the c.971&#95;1018+24del72 deletion was found in 2 patients. The mean age at onset of symptoms in patients with FXII-HAE was 21.1 years. The most common symptoms were subcutaneous edema (85.8% of patients), abdominal pain attacks (69.7%), and upper airway edema (32.3%). Of male individuals carrying F12 mutations, 53.3% (16 of 30) were symptomatic. Compared with reports from Europe, fewer female patients (68.6%) reported an influence of estrogen on symptoms., Conclusions: Our study included a large number of patients with FXII-HAE, and, as the first such study conducted in a South American population, it highlighted significant differences between this and other study populations. The high number of symptomatic males and patients with estrogen-independent FXII-HAE found here suggests that male sex and the absence of a hormonal influence should not discourage clinicians from searching for F12 mutations in cases of HAE with normal C1-INH., (Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Angioedema is an acute swelling of the deeper layers of the skin or mucosa resulting from a transient increase in vascular permeability. Angioedema can occur in the absence or presence of hives, be hereditary or acquired, and be caused by various potential mediators, including histamine and bradykinin. Bradykinin-mediated angioedema can be difficult to diagnose but is responsible for a disproportionate percentage of the serious morbidity and mortality associated with angioedema. Our understanding of the basic biology of angioedema has dramatically expanded over recent years. The classification of angioedema has correspondently undergone major changes. Optimal management of patients with angioedema requires that an accurate diagnosis be established and that treatment be tailored to the patient's specific form of angioedema. In this article, we review the biology of bradykinin-mediated angioedema as well as the clinical approach to the evaluation of angioedema with a focus on bradykinin-mediated angioedema. Recognizing how the underlying pathophysiology and mechanisms of bradykinin dysregulation contribute to angioedema can help guide the clinical approach to the patient., (Copyright © 2018 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: The mechanism of idiopathic nonhistaminergic acquired angioedema (InH-AAE) has not yet been precisely elucidated. This condition is characterized by recurrent angioedema without wheals., Objective: To study the clinical features of InH-AAE, and to make, for the first time, independent comparisons with hereditary angioedema of unknown origin (U-HAE), as well as with hereditary angioedema with C1-inhibitor deficiency (C1-INH-HAE)., Methods: We compared the clinical parameters of 46 patients with InH-AAE with those of 27 patients suffering from U-HAE, as well as of 73 patients with C1-INH-HAE., Results: The mean age at the onset of symptoms was 36 years in InH-AAE, 13 years in C1-INH-HAE, and 29 years in U-HAE. More than 12 edematous episodes occurred over a year in 56% of patients with InH-AAE, in 59% of those with C1-INH-HAE, and in 48% of those with U-HAE. Edema of the extremities, of the upper airways, and of the gastrointestinal tract was more common in patients with C1-INH-HAE (92%, 51%, and 75%, respectively). These manifestations occurred less frequently in patients with InH-AAE (54%, 28%, and 20%) and in patients with U-HAE (37%, 29%, and 20%). By contrast, facial edema occurred in only 15% of patients with C1-INH-HAE, but in 67% of patients with InH-AAE and in 59% of patients with U-HAE., Conclusions: The clinical manifestations of patients with InH-AAE were different from those of patients with C1-INH-HAE. This may indicate different processes underlying edema formation in these disease forms. The close resemblance of the clinical manifestations in InH-AAE and U-HAE might suggest a similarity between the pathophysiology of these conditions., (Copyright © 2018 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Clinical manifestations of hereditary angioedema with C1 inhibitor deficiency (C1-INH-HAE) usually begin in childhood, often intensifying during puberty. Currently there are insufficient efficacy/safety data for HAE therapies in children and adolescents due to the small number of pediatric patients enrolled in studies., Objective: The objective of this phase 3 study was to evaluate the efficacy/safety of a single subcutaneous dose of icatibant (0.4 mg/kg; maximum 30 mg) in pediatric patients with C1-INH-HAE., Methods: Patients aged 2 years to younger than 18 years were categorized as prepubertal (children) and pubertal/postpubertal (adolescents). The primary end point was time to onset of symptom relief-earliest time posttreatment to 20% or more improvement in composite symptom score., Results: Thirty-two patients received icatibant (safety population: 11 children with attack, 10 adolescents without attack, and 11 adolescents with attack). The efficacy population consisted of 11 children and 11 adolescents with edematous attacks. Most attacks in the efficacy population (16 [72.7%]) were cutaneous, 5 (22.7%) were abdominal, and 1 (4.5%) was both cutaneous and abdominal; none was laryngeal. Overall, the median time to onset of symptom relief was 1.0 hour, the same for children and adolescents. Thirty-two treatment-emergent adverse events (all mild or moderate) occurred in 9 (28.1%) patients. Gastrointestinal symptoms were most common (9 events in 3 [9.4%] patients). Injection-site reactions affected most (90.6%) patients (particularly erythema and swelling), but almost all resolved by 6 hours postdose. Icatibant demonstrated a monophasic plasma concentration-time profile. Time to peak concentration was approximately 0.5 hours postdose., Conclusions: Symptom relief was rapid, and a single icatibant injection in pediatric patients with C1-INH-HAE was well tolerated (ClinicalTrials.gov identifier, NCT01386658)., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Recombinant human C1-esterase inhibitor (rhC1-INH) is efficacious and well tolerated for managing hereditary angioedema (HAE) attacks in adults. However, there are insufficient data on its efficacy and safety in adolescents., Objective: To evaluate the efficacy and safety profiles of rhC1-INH for acute HAE attacks in adolescents., Methods: Adolescents (aged 12-18 y) with HAE enrolled in 2 randomized controlled trials and 2 open-label extension trials were included and received intravenous rhC1-INH for acute attacks. Times to the beginning of sustained symptom relief (visual analog scale change from baseline ≥20 mm) and minimal symptoms (visual analog scale score of <20 mm across locations) were assessed. Safety parameters included hypersensitivity reactions, anti-rhC1-INH antibodies, and host-related impurities., Results: Sixteen adolescents (50 attacks, aged 14-18 y) received rhC1-INH. Attacks were managed with single-dose rhC1-INH 50 U/kg (46.0%) and single-dose rhC1-INH 2100 U (16%), and 32.0% were treated with additional doses after receiving an initial rhC1-INH 2100 U dose (total dose, 4200-6300 U). Most attacks (88.0%) occurred at a single location; 59.1% (26 of 44) were abdominal. Across the first 5 attacks, median times to the beginning of symptom relief ranged from 19.0 to 78.5 minutes; median times to minimal symptoms ranged from 120 to 190 minutes. Pharmacokinetics showed that rhC1-INH restored functional plasma C1-esterase inhibitor levels to the normal (>70%) range for almost all evaluable patients. No severe or drug-related adverse events or hypersensitivity reactions occurred. No treatment-emergent antibodies to rhC1-INH or host-related impurities were observed., Conclusions: rhC1-INH is efficacious and well tolerated among adolescents with HAE., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Hereditary angioedema (HAE) is a life-threatening disorder characterized by recurrent angioedema. Icatibant, a subcutaneous bradykinin-B2-receptor antagonist, is an effective on-demand therapy. Data outside the United States suggest that self-administration is tolerated and patient-preferred compared with administration by health care professionals at medical facilities (HCP-administration)., Objective: A prospective, multicenter study was conducted in the United States to compare icatibant self-administration and HCP-administration., Methods: Subjects 18 years or older with type I or II HAE were recruited. The first 2 HAE attacks after enrollment were treated at medical facilities. Subjects were instructed by a health care professional on self-administration during icatibant treatment for the second HAE attack. Icatibant was self-administered for all subsequent attacks. For each treated HAE attack, efficacy, safety, and tolerability data were recorded., Results: Nineteen patients with HAE received icatibant for 79 distinct HAE attacks. Mean attack duration was significantly shorter with self-administration (n = 50; 547 ± 510 minutes) than with HCP-administration (n = 29; 968 ± 717 minutes; P = .006). Mean time to treatment was significantly shorter with self-administration (143 ± 226 minutes) than with HCP-administration (361 ± 503 minutes; P < .0001). Shorter times to treatment were associated with shorter time from treatment to symptom resolution (r = 0.35; P = .02). Improvements in visual analog scale score and patient symptom score from pretreatment to 4 hours postinjection were comparable between self-administration and HCP-administration. There were no serious adverse events or discontinuations due to adverse events with self-administration or HCP-administration., Conclusions: Icatibant self-administration shortened attack duration and time to treatment, with no difference in safety or local tolerability compared with HCP-administration. These findings support icatibant as an effective on-demand option for home-based treatment., (Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Emergency department (ED) management of hereditary angioedema (HAE) has been hindered by misdiagnosis and limited treatment options. Food and Drug Administration approval of 4 on-demand HAE therapies starting in 2009 and the publication of ED guidelines for angioedema management in 2014 should facilitate improvement of HAE management in the ED., Objective: The objective of this study was to identify patient-reported areas for improvement in ED management of HAE attacks., Methods: Patients with self-reported HAE with C1 inhibitor deficiency who attended the 2015 HAE Association Patient Summit were asked to complete an anonymous 30-question survey. Questions addressed patient characteristics and HAE management in the ED., Results: Patients indicated that understanding of HAE in the ED needed improvement (99%, 104 of 105 patients). Recognition of HAE as a diagnosis (48%, 50 of 105 patients), appreciation of HAE as a serious disease (45%, 47 of 105 patients), and medication management (59%, 62 of 105 patients) were identified as areas needing improvement. Among 39 patients who required ED care within the last year, 6 did not receive any HAE-targeted therapy, and treatment with corticosteroids (n = 3), epinephrine (n = 2), and antihistamines (n = 7) was reported. Among 68 patients whose treatment plan was to receive home on-demand therapy, 26 required ED care because of an inability to receive on-demand therapy at home as outlined in their treatment plan. Having a treatment plan was associated with a greater likelihood of receiving HAE therapy in the ED (99% vs 74%, P = .002)., Conclusion: HAE management in the ED can be improved with a focus on recognition of HAE attacks and administration of effective HAE therapies., (Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Hereditary angioedema (HAE) is a genetic disorder clinically characterized by recurrent attacks of subcutaneous and mucosal swelling. 17-α-Alkylated androgens (AA) have been used prophylactically to reduce HAE severity, but there are many questions about the efficacy and tolerability of AA., Objective: The objective of this study was to investigate the tolerability and effectiveness of AA therapy in a large cohort of patients with HAE., Methods: We performed a retrospective cross-sectional study on 650 subjects with HAE utilizing a one time, anonymous, web-based survey. Based on an initial questionnaire, patients were routed to one of the following questionnaires: currently using AA, previously used but discontinued AA, or never used AA., Results: Statistical analysis revealed that androgens decreased attack frequency and severity in previous AA users (P < .0001) and current AA users (P < .0001). Substantial variability in the effectiveness was observed. Users who discontinued AA reported significantly lesser benefit. No dose effect was seen for the beneficial effect of AA; however, almost all users reported frequent side effects that were dose related and often severe., Conclusions: AA therapy is usually effective for the treatment of HAE although a substantial fraction of patients with HAE do not achieve adequate benefit. In contrast, the side effects of AA are seen in almost all subjects who take the medicines. If used, AA should only be recommended in the lowest effective and tolerated dose for carefully selected patients., (Copyright © 2016. Published by Elsevier Inc.)

Background: Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) may affect health-related quality of life (HRQoL). A specific HRQoL questionnaire for adult patients with C1-INH-HAE, the HAE-QoL, has recently been developed in Spain., Objective: The objective of this study was to perform a cross-cultural validation and psychometric study of the HAE-QoL in an international setting., Methods: Cross-cultural adaptation of the Spanish HAE-QoL draft version and an international rating phase with experts were performed. The resultant version of the HAE-QoL, a clinical questionnaire, and Short Form 36-item Health Survey Version 2.0 (SF-36v2) were pilot tested internationally. Item reduction was based on both descriptive and exploratory factor analysis. Psychometric properties were assessed., Results: Cross-cultural adaptation of the HAE-QoL was performed in 18 countries. The draft version of the HAE-QoL was pilot tested in 332 patients, and accurate data were obtained from 290 patients from 11 countries. The reduction process resulted in a new version with 25 items and 7 dimensions (treatment difficulties, physical functioning and health, disease-related stigma, emotional role and social functioning, concern about offspring, perceived control over illness, and mental health). Strong psychometric properties were observed (Cronbach's α 0.92; test-retest reliability 0.87). Convergent validity showed mild to moderate correlations with SF-36v2 physical and mental component summaries (0.45 and 0.64, respectively) and with SF-36v2 dimensions (P < .004). HAE-QoL scores discriminated significantly among severity groups (median: asymptomatic 133.5 vs severe 84.0; P < .001); between patients with and without long-term prophylaxis (median: 101 vs 90; P = .001); and between patients with and without psychiatric and/or psychological care (median: 74 vs 103; P ≤ .001)., Conclusions: The HAE-QoL, currently available in 18 languages, showed good reliability and validity evidence., (Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Hereditary angioedema (HAE) caused by a deficiency in functional C1 esterase inhibitor (C1INH) is characterized by recurrent episodes of cutaneous and/or mucosal/submucosal tissue swelling affecting multiple anatomic locations. Previous studies demonstrated efficacy of recombinant human C1INH (rhC1INH) for acute HAE attacks., Objective: This study evaluated the efficacy and safety of rhC1INH (50 IU/kg) for the treatment of multiple HAE attacks in an open-label extension study., Methods: Time to onset of symptom relief and time to minimal symptoms were assessed using a Treatment Effect Questionnaire (TEQ), a visual analog scale, and a 6-point ordinal scale Investigator Score., Results: Forty-four patients received rhC1INH, and a single dose was administered for 215 of 224 (96%) attacks. Median time to beginning of symptom relief based on TEQ for the first 5 attacks was 75.0 (95% CI, 69-89) minutes, ranging from 62.5 (95% CI, 48-90) to 134.0 (95% CI, 32-119) minutes. Median time to minimal symptoms using TEQ for the first 3 attacks was 303.0 (95% CI, 211-367) minutes. rhC1INH was well tolerated. There were no discontinuations due to adverse events. No thrombotic or anaphylactic events were reported, and repeat rhC1INH treatments were not associated with neutralizing anti-C1INH antibodies., Conclusions: A single 50-IU/kg dose rhC1INH was effective for improving symptoms of an HAE attack with sustained efficacy for treatment of subsequent attacks. rhC1INH had a positive safety profile throughout the study. This study supports repeated use of rhC1INH over time in patients with HAE attacks., (Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: There is a paucity of data that describe the clinical course of hereditary angioedema (HAE) in children., Objective: The purpose of this study was to examine the clinical features of children with HAE., Methods: Electronic medical records from the past 10 years at Cincinnati Children's Hospital Medical Center and an outpatient allergy community practice were searched for ICD-9 code 277.6 (Other deficiencies of circulating enzyme). Exclusion criteria included laboratory data not supportive of type I or II HAE diagnosis or age at diagnosis greater than 18 years. Chart review was performed and missing data were collected by telephone interviews with patient families. Descriptive statistics were performed using SAS version 9.4., Results: Twenty-one children were identified. The median age was 13.2 years (interquartile range [IQR], 9.1-18.8), 71% were male, 86% had an HAE family history, and 95% were Caucasian. The median age of symptom onset and diagnosis was 5.7 (IQR, 5-9 years) and 5.0 (IQR, 4-8 years), respectively. Five children diagnosed were asymptomatic. Three children without a family history had a 6.0-year delay in diagnosis. The most common angioedema attack sites were abdominal, peripheral, and laryngeal, which occurred at least once in 93%, 73%, and 27%, respectively. Of the 15 children with onset of symptoms, only 6 children received on-demand therapy for an acute attack, whereas 13 children were administered either short-term or long-term prophylaxis therapy., Conclusions: In this pediatric HAE population, symptom onset and diagnosis occurred at a median age of 5 years with a delay in diagnosis in those without a family history. Abdominal attacks were more common than peripheral attacks in this population., (Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Ecallantide is a human plasma kallikrein inhibitor indicated for treatment of acute attacks of hereditary angioedema for patients 12 years of age and older. Ecallantide is produced in Pichia pastoris yeast cells by recombinant DNA technology. Use of ecallantide has been associated with a risk of hypersensitivity reactions, including anaphylaxis., Objective: The objective of this detailed retrospective data review was to characterize anaphylaxis cases within the ecallantide clinical trials database., Methods: Potential cases of hypersensitivity reactions in the ecallantide clinical development program were identified by examining reported adverse events. The National Institute of Allergy and Infectious Disease criteria were used to identify those events that were consistent with anaphylaxis; these cases were then reviewed in detail. Results from investigational antibody testing also were examined., Results: Among patients who received subcutaneous ecallantide (n = 230 patients; 1045 doses of 30 mg ecallantide), 8 patients (3.5%) had reactions that met the National Institute of Allergy and Infectious Disease criteria for anaphylaxis; none occurred on first exposure to the drug. All 8 reactions had symptom onset within 1 hour of exposure and cutaneous manifestations commonly observed in type I hypersensitivity reactions. All the reactions responded to standard management of type I hypersensitivity reactions and resolved without fatal outcomes. IgE antibody testing to ecallantide or P pastoris was not consistently positive in patients who experienced apparent type I hypersensitivity reactions., Conclusion: Anaphylaxis episodes after subcutaneous ecallantide exposure have clinical features suggestive of type I hypersensitivity reactions. However, anti-ecallantide or anti-P pastoris IgE antibody status was not found to be reliably associated with anaphylaxis., (Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: A physician survey conducted in the United States between October 2009 and February 2010 revealed wide variability in hereditary angioedema (HAE) management., Objective: A follow-up survey was conducted to assess the impact of newly available treatment options and investigate changes in HAE care patterns., Methods: Between March and June 2013, 6570 physicians were contacted, of whom, 245 HAE-treating physicians responded. Participants completed a 46-question online survey that was closely patterned after the initial survey. Although most data were analyzed descriptively, selected questions underwent statistical analysis to evaluate differences in treatment patterns between the 2 surveys., Results: Compared with the prior survey, this follow-up survey found that the proportion of physicians who reported danazol as the preferred long-term prophylaxis agent declined from 56% to 23% (P < .00005); conversely, C1-esterase inhibitor increased in this category (20% to 57%; P < .00005). The percentage of attacks self-treated at home increased from 8% to 27% (P < .00005). Decreases were observed in emergency department visits (61% to 54%; P = not significant) and hospitalizations (13% to 3%; P = .0001) for HAE attacks. The percentage of patients perceived by physicians to be very satisfied with HAE treatment increased from 13% to 40% (P < .00005). In 2013, convenience was reported more frequently as an important patient factor that drove long-term prophylaxis choice (27% vs 10%; P < .00005), whereas adverse effects were cited less frequently (16% vs 42%; P < .00005); in both surveys, cost and/or insurance coverage was the greatest driver in this category (43% and 46%)., Conclusion: Analysis of these findings suggests that the change in HAE treatment has increased self-treatment at home, decreased emergency department visits and/or hospitalizations, and provided greater patient satisfaction., (Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Introduction: Measuring functional C1 inhibitor (C1 INH) with chromogenic or ELISA methods can confirm a diagnosis of hereditary angioedema (HAE) due to C1 INH deficiency. Previous studies found differences in the agreement of these assays., Objective: To evaluate the agreement between chromogenic or ELISA methods in the context of an observational study., Methods: Patients with previously confirmed HAE underwent functional C1 INH testing. These patients contacted first-degree relatives (parents, siblings, or offspring) not previously evaluated for HAE, who underwent a panel of complement testing, including for functional C1 INH., Results: Overall, 31 patients with HAE and 46 untested relatives enrolled. Of 46 relatives, 14 (30.4%) were newly diagnosed with HAE based on their laboratory results. Among the 31 patients previously confirmed with HAE, all had low functional C1 INH according to the chromogenic method, whereas 22 (71.0%) had low, 7 (22.6%) had equivocal, and 2 (6.5%) had normal functional C1 INH according to the ELISA method. In the 14 newly diagnosed relatives, all had low functional C1 INH according to the chromogenic method, whereas 11 (78.5%) had low and 3 (21.4%) had equivocal results according to the ELISA method., Conclusion: Despite the apparent discordance in the ELISA and chromogenic assays in a small number of patients, both were useful in measuring functional C1 INH. To establish the diagnosis of HAE due to C1 INH deficiency, functional C1 INH results should be interpreted in combination with family and clinical history, and with other complement tests., (Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Nanofiltered C1 inhibitor (human) is approved in the United States for routine prophylaxis of angioedema attacks in patients with hereditary angioedema, a rare disease caused by a deficiency of functional C1 inhibitor., Objective: To assess the safety of escalating doses of nanofiltered C1 inhibitor (human) in patients who were not adequately controlled on the indicated dose (1000 U every 3 or 4 days)., Methods: Eligible patients had >1 attack/month over the 3 months before the trial. Doses were escalated to 1500 U every 3 or 4 days for 12 weeks, at which point, the patients were evaluated. If treatment was successful (≤1 attack/mo) or at the investigator's discretion, the patients entered a 3-month follow-up period. The patients with an average of >1 attack/month were eligible for further escalation to 2000 U and then 2500 U., Results: Twenty patients started at 1500 U; 13 were escalated to 2000 U, and 12 were escalated to 2500 U. Eighteen patients reported adverse events. Two patients reported 4 serious adverse events (cerebral cystic hygroma, laryngeal angioedema attack, anemia, and bile duct stone) that were considered by investigators to be unrelated to treatment. Notably, there were no systemic thrombotic events or discontinuations due to adverse events. Fourteen patients were treated successfully (70%), continued to the follow-up period at the investigator's discretion, or experienced a reduction in attacks of >1.0/month., Conclusions: Dose escalation of nanofiltered C1 inhibitor (human) up to 2500 U was well tolerated and reduced attack frequency in the majority of patients., (Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Hereditary angioedema (HAE) with normal C1 inhibitor (C1-INH), also known as HAE type III, is a familial condition only clinically recognized within the past three decades. Similar to HAE from C1-INH deficiency (HAE types I and II), affected individuals experience unpredictable angioedema episodes of the skin, gastrointestinal tract, and airway. Unique clinical features of HAE with normal C1-INH include the predominance of affected women, frequent exacerbation by estrogen, and a prominence of angioedema that involves the face and oropharynx. The underlying pathophysiology of HAE with normal C1-INH is poorly understood, but indirect evidence points to contact pathway dysregulation with bradykinin-mediated angioedema. Currently, evaluation is complicated by a lack of confirmatory laboratory testing such that clinical criteria must often be used to make the diagnosis of HAE with normal C1-INH. Factor XII mutations have been identified in only a minority of persons affected by HAE with normal C1-INH, limiting the utility of such analysis. To date, no controlled clinical studies have examined the efficacy of therapeutic agents for HAE with normal C1-INH, although published evidence supports frequent clinical benefit with medications shown effective in HAE due to C1-INH deficiency., (Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: The treatment of hereditary angioedema (HAE) has undergone dramatic changes as newer medicines have become available in recent years. Optimal care of these patients requires a comprehensive management plan. Although several consensus papers have been published concerning the diagnosis and treatment of HAE, guidelines for a comprehensive management plan have not been developed., Objective: To develop state-of-the-art recommendations for the treatment and management of HAE due to C1 inhibitor (C1INH) deficiency in the United States., Methods: Members of the US Hereditary Angioedema Association Medical Advisory Board began by reviewing the literature concerning treatment of HAE. Preliminary recommendations were developed based on the literature review, discussions in a face-to-face meeting, and refinements in a series of drafts. Final recommendations reflect the unanimous consensus of the medical advisory board and the US Hereditary Angioedema Association leadership., Results: Recommendations are provided regarding a comprehensive care plan for HAE, including the following: development of an overall management plan, treatment of angioedema attacks, prophylactic treatment, and patient monitoring., Conclusion: A comprehensive individualized management plan developed between an expert HAE physician and the patient, in collaboration with local medical providers and emergency departments, can provide patients with the best opportunity to lead a normal life., (Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)