Home therapy with intravenous human C1-inhibitor in children and adolescents with hereditary angioedema

Consensus on diagnosis and management of Hereditary Angioedema in the Middle East: A Delphi initiative

Background

Hereditary angioedema (HAE), a potentially life-threatening genetic disorder due to C1 inhibitor deficiency in most cases, is characterized by sudden and/or recurrent attacks of angioedema (subcutaneous/submucosal swellings). The global World Allergy Organization (WAO)/European Academy of Allergy and Clinical Immunology (EAACI) International guideline for HAE management is comprehensive, but the implementation of this guideline may require regional adaptation considering the diversity in disease awareness, type of medical care systems, and access to diagnostics and treatment. The aim of this Delphi initiative was to build on the global guideline and provide regional adaptation to address the concerns and specific needs in the Middle East.

Methods

The Consensus panel comprised 13 experts from the Middle East (3 from the United Arab Emirates, 3 from Saudi Arabia, 2 from Lebanon, 2 from Kuwait, 2 from Oman and 1 from Qatar) who have more than 2 decades of experience in allergy and immunology and are actively involved in managing HAE patients. The process that was carried out to reach the consensus recommendation included: 1.) A systematic literature review for articles related to HAE management using Ovid MEDLINE. 2.) The development of a questionnaire by an internationally acclaimed expert, with 10 questions specific to HAE management in the Middle East. 3.) Experts received the questionnaire via email individually and their answers were recorded (email/interview). 4.) A virtual consensus meeting was organized to discuss the questionnaire, make amends if needed, vote, and achieve consensus.

Results

The questionnaire comprised 10 questions, each with 2 or more statements/recommendations on which the regional experts voted. A consensus was reached based on a 70% agreement between the participants. The key highlights include: 1) HAE experts in the Middle East emphasized the importance of a positive family history for arriving at a diagnosis of HAE. 2) The number of episodes per month or per 6-month period and severity should be used, together with other markers, to determine the need for prophylaxis. 3) Disease status should be monitored by periodic visits and the use of patient-reported outcome measures such as the angioedema activity score and the angioedema control test. 4) Attenuated androgens and tranexamic acid may be considered for long-term prophylaxis, if lanadelumab, C1-Inhibitor or berotralstat are not available.

Conclusion

This consensus recommendation may help to educate healthcare practitioners in the Middle East and unify their approach to the diagnosis and management of HAE.

The international WAO/EAACI guideline for the management of hereditary angioedema - The 2021 revision and update

Hereditary Angioedema (HAE) is a rare and disabling disease for which early diagnosis and effective therapy are critical. This revision and update of the global WAO/EAACI guideline on the diagnosis and management of HAE provides up-to-date guidance for the management of HAE. For this update and revision of the guideline, an international panel of experts reviewed the existing evidence, developed 28 recommendations, and established consensus by an online DELPHI process. The goal of these recommendations and guideline is to help physicians and their patients in making rational decisions in the management of HAE with deficient C1-inhibitor (type 1) and HAE with dysfunctional C1-inhibitor (type 2), by providing guidance on common and important clinical issues, such as: 1) How should HAE be diagnosed? 2) When should HAE patients receive prophylactic on top of on-demand treatment and what treatments should be used? 3) What are the goals of treatment? 4) Should HAE management be different for special HAE patient groups such as children or pregnant/breast feeding women? 5) How should HAE patients monitor their disease activity, impact, and control? It is also the intention of this guideline to help establish global standards for the management of HAE and to encourage and facilitate the use of recommended diagnostics and therapies for all patients.

The international WAO/EAACI guideline for the management of hereditary angioedema-The 2021 revision and update

Hereditary angioedema (HAE) is a rare and disabling disease for which early diagnosis and effective therapy are critical. This revision and update of the global WAO/EAACI guideline on the diagnosis and management of HAE provides up-to-date guidance for the management of HAE. For this update and revision of the guideline, an international panel of experts reviewed the existing evidence, developed 28 recommendations, and established consensus by an online DELPHI process. The goal of these recommendations and guideline is to help physicians and their patients in making rational decisions in the management of HAE with deficient C1 inhibitor (type 1) and HAE with dysfunctional C1 inhibitor (type 2), by providing guidance on common and important clinical issues, such as: (1) How should HAE be diagnosed? (2) When should HAE patients receive prophylactic on top of on-demand treatment and what treatments should be used? (3) What are the goals of treatment? (4) Should HAE management be different for special HAE patient groups such as children or pregnant/breast-feeding women? and (5) How should HAE patients monitor their disease activity, impact, and control? It is also the intention of this guideline to help establish global standards for the management of HAE and to encourage and facilitate the use of recommended diagnostics and therapies for all patients.

A novel reflective practice intervention improves quality of care in the emergency department

INTRODUCTION

Most interventions to improve clinical outcomes in the emergency department (ED) are based on structural changes. This study embraced a different strategy and examined the impact of a reflective practice intervention (RPI) on ED quality of care.

METHODS

A pre-post-intervention quasi-experimental nested design was conducted between January 2017 and June 2018 in an Israeli public tertiary academic ED. Nighty-six ED teams (triage and staff nurses and a physician) were included pre and post RPI. Data were collected pre and post RPI at patient-triage nurse encounters using triage-accuracy questionnaires. Time to decision, length-of-stay, and hospitalization and mortality rates were retrieved from the medical charts of 1920 patients (20 per team).

RESULTS

Accurate triage was significantly higher post than pre intervention (4.84 ± 1.45 vs. 3.87 ± 1.48; range 1-7; p < .001), whereas time to decision (253.30 ± 246.75 vs. 304.64 ± 249.14 min), hospitalization rates (n = 291, 30.3% vs. n = 374, 39.0%; p < .001), and hospital length-of-stay (5.73 ± 6.72 vs. 6.69 ± 6.20; p = .04) significantly decreased.

CONCLUSIONS

By adapting organizational reflective practice principles to the ED dynamic environment, the RPI was associated with a significant improvement in ED quality-of-care measures.

Hereditary angioedema in children and adolescents - A consensus update on therapeutic strategies for German-speaking countries

BACKGROUND/METHODS

At a consensus meeting in August 2018, pediatricians and dermatologists from German-speaking countries discussed the therapeutic strategy for the treatment of pediatric patients with type I and II hereditary angioedema due to C1 inhibitor deficiency (HAE-C1-INH) for Germany, Austria, and Switzerland, taking into account the current marketing approval status. HAE-C1-INH is a rare disease that usually presents during childhood or adolescence with intermittent episodes of potentially life-threatening angioedema. Diagnosis as early as possible and an optimal management of the disease are important to avoid ineffective therapies and to properly treat swelling attacks. This article provides recommendations for developing appropriate treatment strategies in the management of HAE-C1-INH in pediatric patients in German-speaking countries. An overview of available drugs in this age-group is provided, together with their approval status, and study results obtained in adults and pediatric patients.

RESULTS/CONCLUSION

Currently, plasma-derived C1 inhibitor concentrates have the broadest approval status and are considered the best available option for on-demand treatment of HAE-C1-INH attacks and for short- and long-term prophylaxis across all pediatric age-groups in German-speaking countries. For on-demand treatment of children aged 2 years and older, recombinant C1-INH and bradykinin-receptor antagonist icatibant are alternatives. For long-term prophylaxis in adolescents, the parenteral kallikrein inhibitor lanadelumab has recently been approved and can be recommended due to proven efficacy and safety.

US HAEA Medical Advisory Board 2020 Guidelines for the Management of Hereditary Angioedema

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.

The International/Canadian Hereditary Angioedema Guideline

This is an update to the 2014 Canadian Hereditary Angioedema Guideline with an expanded scope to include the management of hereditary angioedema (HAE) patients worldwide. It is a collaboration of Canadian and international HAE experts and patient groups led by the Canadian Hereditary Angioedema Network. The objective of this guideline is to provide evidence-based recommendations, using the GRADE system, for the management of patients with HAE. This includes the treatment of attacks, short-term prophylaxis, long-term prophylaxis, and recommendations for self-administration, individualized therapy, quality of life, and comprehensive care. New to the 2019 version of this guideline are sections covering the diagnosis and recommended therapies for acute treatment in HAE patients with normal C1-INH, as well as sections on pregnant and paediatric patients, patient associations and an HAE registry. Hereditary angioedema results in random and often unpredictable attacks of painful swelling typically affecting the extremities, bowel mucosa, genitals, face and upper airway. Attacks are associated with significant functional impairment, decreased health-related quality of life, and mortality in the case of laryngeal attacks. Caring for patients with HAE can be challenging due to the complexity of this disease. The care of patients with HAE in Canada, as in many countries, continues to be neither optimal nor uniform. It lags behind some other countries where there are more organized models for HAE management, and greater availability of additional licensed therapeutic options. It is anticipated that providing this guideline to caregivers, policy makers, patients, and advocates will not only optimize the management of HAE, but also promote the importance of individualized care. The primary target users of this guideline are healthcare providers who are managing patients with HAE. Other healthcare providers who may use this guideline are emergency and intensive care physicians, primary care physicians, gastroenterologists, dentists, otolaryngologists, paediatricians, and gynaecologists who will encounter patients with HAE and need to be aware of this condition. Hospital administrators, insurers and policy makers may also find this guideline helpful.

Evaluation and Management of Angioedema in the Emergency Department

Angioedema is defined by non-dependent, non-pitting edema that affects several different sites and is potentially life-threatening due to laryngeal edema. This narrative review provides emergency physicians with a focused overview of the evaluation and management of angioedema. Two primary forms include histamine-mediated and bradykinin-mediated angioedema. Histamine-mediated forms present similarly to anaphylaxis, while bradykinin-mediated angioedema presents with greater face and oropharyngeal involvement and higher risk of progression. Initial evaluation and management should focus on evaluation of the airway, followed by obtaining relevant historical features, including family history, medications, and prior episodes. Histamine-mediated angioedema should be treated with epinephrine intramuscularly, antihistaminergic medications, and steroids. These medications are not effective for bradykinin-mediated forms. Other medications include C1-INH protein replacement, kallikrein inhibitor, and bradykinin receptor antagonists. Evidence is controversial concerning the efficacy of these medications in an acute episode, and airway management is the most important intervention when indicated. Airway intervention may require fiberoptic or video laryngoscopy, with preparation for cricothyrotomy. Disposition is dependent on patient's airway and respiratory status, as well as the sites involved.

Acquired and hereditary forms of recurrent angioedema: Update of treatment

The aim of treatment of hereditary angioedema (HAE) due to C1 esterase inhibitor deficiency (HAE-C1-INH) is either treating acute attacks or preventing attacks by using prophylactic treatment. For treating acute attacks, plasma-derived C1 inhibitor (C1-INH) concentrates, a bradykinin B2 receptor antagonist, and a recombinant human C1-INH are available in Europe. In the United States, a plasma-derived C1-INH concentrate, a bradykinin B2 receptor antagonist, and a plasma kallikrein inhibitor were approved for the treatment of acute attacks. Fresh frozen plasma is also available for treating acute attacks. Short-term prophylactic treatment focuses on C1-INH and attenuated androgens. Long-term prophylactic treatments include attenuated androgens such as danazol, stanozolol, and oxandrolone, antifibrinolytics, and a plasma-derived C1-INH concentrate. Plasma-derived C1-INH and a bradykinin B2 receptor antagonist are admitted for self-administration and home therapy. So the number of management options increased considerably within the last few years thus helping to diminish the burden of HAE.

The international WAO/EAACI guideline for the management of hereditary angioedema-The 2017 revision and update

Hereditary Angioedema (HAE) is a rare and disabling disease. Early diagnosis and appropriate therapy are essential. This update and revision of the global guideline for HAE provides up-to-date consensus recommendations for the management of HAE. In the development of this update and revision of the guideline, an international expert panel reviewed the existing evidence and developed 20 recommendations that were discussed, finalized and consented during the guideline consensus conference in June 2016 in Vienna. The final version of this update and revision of the guideline incorporates the contributions of a board of expert reviewers and the endorsing societies. The goal of this guideline update and revision is to provide clinicians and their patients with guidance that will assist them in making rational decisions in the management of HAE with deficient C1-inhibitor (type 1) and HAE with dysfunctional C1-inhibitor (type 2). The key clinical questions covered by these recommendations are: (1) How should HAE-1/2 be defined and classified?, (2) How should HAE-1/2 be diagnosed?, (3) Should HAE-1/2 patients receive prophylactic and/or on-demand treatment and what treatment options should be used?, (4) Should HAE-1/2 management be different for special HAE-1/2 patient groups such as pregnant/lactating women or children?, and (5) Should HAE-1/2 management incorporate self-administration of therapies and patient support measures?

Value co-creation in healthcare: evidence from innovative therapeutic alternatives for hereditary angioedema

BACKGROUND

Our research focuses on the co-creation of value in healthcare with reference to a case of hereditary angioedema with C1 inhibitor deficiency (C1-INH-HAE). Our work is mainly based on the concept of value co-creation in healthcare. The aim of this study is to assess the impact of an alternative treatment strategy - self-administration - by focusing on treatment outcomes and costs to understand if innovative therapeutic solutions can create value for patients and healthcare systems.

METHODS

This paper compares home-based and hospital-based therapeutic strategies (independent of treatment type) with a cost minimization analysis. It encompasses compliance issues and focuses on both payer and societal perspectives, also benefiting from an operationalization of the service-dominant logic model for healthcare delivery. Data were collected over a 6-month period (August 2014-January 2015) through monthly patient interviews. Archival data were used for variable measurement.

RESULTS

Thirty-nine out of 62 patients enrolled in the study, experienced at least one HAE attacks, equally distributed between home and hospital-based strategies. No evidence of correlation between therapeutic strategy and disease severity score (p = 0.351), compliance (p = 0.399), and quality of life (p = 0.971), were found. Total direct cost per attack amounts to € 1224 for home-based strategy with respect to € 1454 for hospital-based strategy, with a savings of € 230. The economic advantage of the home-based strategy almost doubles if the societal perspective was considered due to a further savings of €169 (less missed work/school days and no travel expenses).

CONCLUSIONS

Our study suggests that home-based therapies represent a feasible strategy for managing C1-INH-HAE and may result in lower costs and increased value for both patients and the healthcare systems. The findings are relevant to the debate on and extend the extant literature to provide a broader view of value co-creation dynamics for home-based therapies in healthcare and their positive effects. The insights are relevant to practitioners and policy makers.

Icatibant for the treatment of hereditary angioedema with C1-inhibitor deficiency in adolescents and in children aged over 2 years

INTRODUCTION

Hereditary angioedema (HAE) due to C1-inhibitor deficiency (C1-INH-HAE) is a rare disorder with life-threatening complications if untreated. It begins during childhood, and reduces the patient's quality of life. Therefore, the availability of an easily administered agent to relieve unpredictable HAE episodes is indispensable for this age group. Areas covered: Randomized, double-blind, placebo-controlled, open-label extensions and prospective observational studies have proven the safety and efficacy of the subcutaneously administered bradykinin B2 receptor antagonist, icatibant, in the acute treatment of HAE episodes in adult C1-INH-HAE patients. Recently, a Phase 3, multicenter, open-label, non-randomized, single-arm study demonstrated the efficacy, safety, and tolerability of icatibant as an acute treatment for pediatric patients aged 2 years to less than 18 years. Expert commentary: The clinical study in pediatric patients showed that icatibant undergoes rapid absorption, reaches a therapeutic level, and promptly relieves the symptoms. It is well tolerated, and the subcutaneous preparation, presented in a pre-filled syringe, ensures ease of use. It can be administered anytime, anywhere, and instantly - even by the patients themselves, or - in the case of children and adolescents - by a caregiver. Icatibant may greatly contribute to the improvement of the quality of life of pediatric patients.

Safety, effectiveness, and impact on quality of life of self-administration with plasma-derived nanofiltered C1 inhibitor (Berinert®) in patients with hereditary angioedema: the SABHA study

BACKGROUND

Hereditary angioedema with C1 inhibitor deficiency is a disabling, potentially fatal condition characterized by recurrent episodes of swelling. Self-treatment is recommended, in order to reduce admissions to the Emergency Room and the time between the onset of the attack and the treatment, resulting in a better treatment outcome and an improved quality of life (QoL). The purpose of this study is to assess the safety, tolerability, and effect on QoL of self-administration of pnf C1-INH for IV use (Berinert®).

METHODS

An observational, monocenter, prospective study was designed. Patients referring to a center for angioedema that attended two sessions of self-infusion training course in the period March 2014-July 2015 were enrolled in the study. The primary endpoint was to monitor the safety and feasibility of pnf C1-INH self-infusion. The secondary endpoint was to evaluate the effect of self-infusion on the QoL, by means of the HAE-QoL questionnaire and the need for access to Emergency Room for infusion of Berinert®. Patients' medical history data were collected upon the first visit and questionnaires were filled after each attack treated with Berinert® (diary and Treatment Satisfaction Questionnaire for Medication) and upon the first visit and the follow-ups (HAE-QoL).

RESULTS

Twenty patients were enrolled (median age = 42, IQR: 39-49; 60% females). Fifteen patients completed the study. A total of 189 attacks were recorded (annual median rate of 4 attacks/patient). Patients waited a median of 2 h (IQR: 1-4) before self-administration, and the resolution of the attack occurred after a median of 6 h (IQR: 4-11). Most attacks were abdominal (39%) and peripheral (22%). 92% of the attacks were treated through self-/caregiver-administration. In most attacks no side effects were reported. The number of attacks with side effects decreased over time, from 37% to 13%. Global satisfaction grew over time during the study period, reaching statistical significance over the first 6 months. The median total HAE-QoL score at baseline was 86 (IQR: 76-103) and improved in a non-significant manner throughout the study period. 8% of the attacks treated with Berinert® required ER admission/healthcare professional help in the study period, compared with 100% in the 3 years before enrollment (p < 0.0001).

CONCLUSIONS

Self-administration of pnf C1-INH is safe, and increases patients' confidence in the treatment, showing also a trend towards an improvement in QoL. It reduces the need for ER admission/healthcare professionals help for the acute attacks, as well as the related costs.

Pharmacological Management of Hereditary Angioedema with C1-Inhibitor Deficiency in Pediatric Patients

Hereditary angioedema with C1-inhibitor deficiency (C1-INH-HAE) is a form of bradykinin-mediated angioedema. It is a rare disorder with an onset during childhood in most instances. Therefore, familiarity with the options for the management of pediatric cases is indispensable. The recurrent angioedematous episodes do not respond to conventional treatments and may evolve into a life-threatening condition. In view of the recommendations adopted by international consensus in 2016, patient management and follow-up should be guided by an individualized strategy. During the last decade, various medicinal products with novel modes of action and different posology have been developed for the treatment of C1-INH-HAE. These drugs either inhibit the release of bradykinin (plasma-derived C1-inhibitors, recombinant C1-inhibitors, kallikrein inhibitors) or prevent the released bradykinin from binding to its receptor (bradykinin B₂ receptor antagonists). This review summarizes the properties of the medicinal products currently available for the treatment of C1-INH-HAE, the indications for their use in pediatric patients, and the findings of the clinical trials conducted in this patient population. It is concluded by a brief outline of future therapeutic options.

Optimum Use of Acute Treatments for Hereditary Angioedema: Evidence-Based Expert Consensus

Acute treatment of hereditary angioedema due to C1 inhibitor deficiency has become available in the last 10 years and has greatly improved patients’ quality of life. Two plasma-derived C1 inhibitors (Berinert and Cinryze), a recombinant C1 inhibitor (Ruconest/Conestat alpha), a kallikrein inhibitor (Ecallantide), and a bradykinin B2 receptor inhibitor (Icatibant) are all effective. Durably good response is maintained over repeated treatments and several years. All currently available prophylactic agents are associated with breakthrough attacks, therefore an acute treatment plan is essential for every patient. Experience has shown that higher doses of C1 inhibitor than previously recommended may be desirable, although only recombinant C1 inhibitor has been subject to full dose–response evaluation. Treatment of early symptoms of an attack, with any licensed therapy, results in milder symptoms, more rapid resolution and shorter duration of attack, compared with later treatment. All therapies have been shown to be well-tolerated, with low risk of serious adverse events. Plasma-derived C1 inhibitors have a reassuring safety record regarding lack of transmission of virus or other infection. Thrombosis has been reported in association with plasma-derived C1 inhibitor in some case series. Ruconest was associated with anaphylaxis in a single rabbit-allergic volunteer, but no further anaphylaxis has been reported in those not allergic to rabbits despite, in a few cases, prior IgE sensitization to rabbit or milk protein. Icatibant is associated with high incidence of local reactions but not with systemic effects. Ecallantide may cause anaphylactoid reactions and is given under supervision. For children and pregnant women, plasma-derived C1 inhibitor has the best evidence of safety and currently remains first-line treatment.

Use of a C1 Inhibitor Concentrate in Adults ≥65 Years of Age with Hereditary Angioedema: Findings from the International Berinert® (C1-INH) Registry

Background

Treatment of hereditary angioedema (HAE) in ‘older adults’ (those aged ≥65 years) has not been well studied. The international Berinert Patient Registry collected data on the use of intravenous plasma-derived, pasteurized, nanofiltered C1-inhibitor concentrate (pnfC1-INH; Berinert^®/CSL Behring) in patients of any age, including many older adults.

Methods

This observational registry, conducted from 2010 to 2014 at 30 US and seven European sites, gathered prospective (post-enrollment) and retrospective (pre-enrollment) usage and adverse event (AE) data on subjects treated with pnfC1-INH.

Results

The registry documented 1701 pnfC1-INH infusions in 27 older adults. A total of 1511 HAE attacks treated with pnfC1-INH administration were reported among 25 of the 27 (92.6 %) older adults. Among the older adults, mean (standard deviation [SD]) (8.8 [4.1] IU/kg) and median (6.4 IU/kg) pnfC1-INH doses were lower than those reported for 252 ‘younger adults’ (those aged <65 years: 12.9 [6.2], 12.5 IU/kg, respectively). A total of 19 AEs occurred in 8 of 23 (34.8 %) older adults with prospective data, for rates of 0.83 events per subject and 0.02 events per infusion, similar to corresponding rates in younger adults (0.91 and 0.03, respectively). None of the AEs were considered related to pnfC1-INH, and all but two events (prostatectomy, gastrointestinal bleeding) were mild or moderate in severity. Administration of pnfC1-INH outside of a healthcare setting was reported for 1609 infusions in 16 older adults, representing 94.6 % of all pnfC1-INH infusions in this age group. There were no recorded instances of difficulty with self-administration of intravenous pnfC1-INH.

Conclusions

These findings suggest a high degree of safety with intravenous pnfC1-INH use in older adults with HAE, regardless of administration setting.

Trial Registration Clinicaltrials.gov NCT01108848.

Pediatric Angioedema

PURPOSE OF REVIEW

The aims of this study are to update the clinician on current understanding of angioedema as it presents in the pediatric population and to review proper diagnostic techniques and treatment modalities for various types of angioedema.

RECENT FINDINGS

Angioedema is still best classified by whether it is likely histaminergic or kinin-mediated. New guidelines have been published around the world to help diagnose and treat both forms (urticaria/angioedema and hereditary angioedema). The vast majority of the studies on treatment have been conducted in the adult population; however, there are data available in the pediatric population. In the realm of hereditary angioedema, there are multiple new therapies that have been studied in the pediatric population (down to 2 years in some studies) in recent years and offer the clinician options for treatment. Angioedema (whether occurring with or without urticaria) is common in the pediatric population. The majority of the recent studies has been conducted in hereditary angioedema, and now, the clinician should have various options to treat all forms of angioedema. Many treatment options, especially for hereditary angioedema, are further being examined specifically in the pediatric population.

Clinical characteristics and real-life diagnostic approaches in all Danish children with hereditary angioedema

Background

With a potentially early onset, hereditary angioedema (HAE) requires special knowledge also in infancy and early childhood. In children from families with HAE, the diagnosis should be confirmed or refuted early, which can be difficult. Studies of childhood HAE and the diagnostic approaches are limited. Our aim was to investigate the entire Danish cohort of children with HAE and non-HAE children of HAE patients for diagnostic approaches and clinical characteristics.

Results

We included 41 children: 22 with HAE and 19 non-HAE. Of the HAE children, 14 were symptomatic—median age at onset was 4 [1–11] years. The first attack was peripheral in 8/14 children and abdominal in 6/14 children, i.e. no one had their first attacks in the upper airways. Most children had less than one attack per month. All of the symptomatic children had been treated with tranexamic acid and/or C1 inhibitor concentrate. Unlike in other countries, androgens were not used in our pediatric cohort. Home therapy with C1 inhibitor concentrate was established in 9 cases: 6 children were trained in self-administration and 3 children were treated by parents. Of the children, 10 had been diagnosed by symptoms, including 3 without family history—median age of diagnosis among these children was 5.35 [2–13.2] years. In 31 children, HAE was diagnosed or refuted before symptoms by blood samples. In 23 of these children, complement values were investigated, and in 9 cases genetic testing was added to the complement measurements. In 8 children recently investigated, genetic testing was first choice. Cord blood was used for complement measurements in 9 children and for genetic testing in 4 children. Results of complement measurements were equivocal in several cases, especially in the cord blood samples, and the sensitivity of low complement C4 for the diagnosis of HAE was 75%.

Conclusions

We investigated clinical characteristics in all Danish children with HAE. The rate of home therapy was high and androgens had been avoided. Complement values were often equivocal, especially in cord blood samples. Consequently, we have changed diagnostic practice to early genetic testing in children where the family mutation is known.

International consensus on the diagnosis and management of pediatric patients with hereditary angioedema with C1 inhibitor deficiency

Background

The consensus documents published to date on hereditary angioedema with C1 inhibitor deficiency (C1‐INH‐HAE) have focused on adult patients. Many of the previous recommendations have not been adapted to pediatric patients. We intended to produce consensus recommendations for the diagnosis and management of pediatric patients with C1‐INH‐HAE.

Methods

During an expert panel meeting that took place during the 9th C1 Inhibitor Deficiency Workshop in Budapest, 2015 (www.haenet.hu), pediatric data were presented and discussed and a consensus was developed by voting.

Results

The symptoms of C1‐INH‐HAE often present in childhood. Differential diagnosis can be difficult as abdominal pain is common in pediatric C1‐INH‐HAE, but also commonly occurs in the general pediatric population. The early onset of symptoms may predict a more severe subsequent course of the disease. Before the age of 1 year, C1‐INH levels may be lower than in adults; therefore, it is advisable to confirm the diagnosis after the age of one year. All neonates/infants with an affected C1‐INH‐HAE family member should be screened for C1‐INH deficiency. Pediatric patients should always carry a C1‐INH‐HAE information card and medicine for emergency use. The regulatory approval status of the drugs for prophylaxis and for acute treatment is different in each country. Plasma‐derived C1‐INH, recombinant C1‐INH, and ecallantide are the only agents licensed for the acute treatment of pediatric patients. Clinical trials are underway with additional drugs. It is recommended to follow up patients in an HAE comprehensive care center.

Conclusions

The pediatric‐focused international consensus for the diagnosis and management of C1‐INH‐HAE patients was created.

Prophylaxis in hereditary angioedema (HAE) with C1 inhibitor deficiency

Hereditary angioedema (HAE) is a rare congenital disorder characterized by recurrent episodes of subcutaneous or submucosal edema. Laryngeal manifestations can be life-threatening. In the majority of cases, the disease can be adequately treated with an on-demand approach--in some cases, however, short- or long-term prophylaxis is indicated. Attenuated androgens used to be the drugs of choice, but they are associated with considerable side effects and no longer commercially available in the German-speaking countries of the EU. They are currently being replaced by more effective and more tolerable agents such C1-inhibitors, the kallikrein inhibitor ecallantide, and the B2 receptor antagonist icatibant, which have recently obtained market authorization. These new drugs have had a major impact, especially on the indications and procedures for long-term prophylaxis. According to the most recent international consensus papers and our own experience, self-administered C1-inhibitors are now the first option for long-term prophylactic therapy. The decision for prophylaxis should no longer be based on single parameters such as the frequency of attacks but on adequate overall disease control including quality of life. More drugs are currently being developed, which may lead to further changes in the treatment algorithms of HAE.

Management of Children With Hereditary Angioedema Due to C1 Inhibitor Deficiency

Hereditary angioedema (HAE) is a potentially life-threatening inherited disease characterized by attacks of skin swelling, severe abdominal pain, and upper airway swelling. Attacks typically begin in childhood, but the appropriate diagnosis is often missed. Attacks do not respond to epinephrine, antihistamines, or glucocorticoids. Recently, many effective drugs have been approved for treatment of adults with HAE, and the Medical Advisory Board of the HAE Patient's Association has developed and reported treatment recommendations for adults. Only 1 medication is approved for treatment of children <12 years of age, and there are no reported consensus recommendations for treatment of young children in the United States. The 11-member Medical Advisory Board, with extensive experience in the treatment of children, in concert with the leaders of the HAE Patient's Association, has developed these consensus recommendations to help in recognition, diagnosis, treatment of attacks, and prophylaxis of children with HAE.

High attack frequency in patients with angioedema due to C1-inhibitor deficiency is a major determinant in switching to home therapy: a real-life observational study

BACKGROUND

Hereditary angioedema with C1-inhibitor deficiency (C1-INH-HAE) is characterized by recurrent attacks of swelling that affect various body sites. Such attacks are a frequent cause of visits to the emergency department and are often treated in the hospital. In recent years, self-administration of C1-inhibitor (C1-INH) concentrates at home has become an increasingly used option, with a positive impact on patient outcomes and quality of life.

METHODS

This was an observational study of 6 months' duration in 56 patients with C1-INH-HAE referred to a HAE center in southern Italy. The patients received three types of treatment for their swelling attacks: C1-INH concentrates administered at home (n = 25); icatibant administered at home (n = 12); and C1-INH concentrates administered in the hospital (n = 19). The objectives of this observational study were to compare therapy compliance (defined as the proportion of treated attacks) and quality of life in home- and hospital-treated patients, and to identify factors associated with the decision to use home therapy.

RESULTS

Overall, 918 attacks were reported over 6 months, of which 544 (59.2 %) were treated. Total number of reported attacks and the mean (±SD) number of attacks per patient, respectively, in the three groups were: 611 and 24.4 (±26.1) for home-based C1-INH; 191 and 15.9 (±12.0) for home-based icatibant; 166 and 6.1 (±6.5) for hospital-based C1-INH. Differences in attack frequency between home- and hospital-based treatments were statistically significant (p = 0.002), while patient demographic characteristics and the disease severity score did not correlate with the use of home therapy. Compliance with therapy was significantly better with home-based therapy (71.2 % of treated attacks with C1-INH and 44.0 % with icatibant) than with hospital-based therapy (21.6 %, p = 0.003). Quality of life showed an opposite trend, with patients on hospital-based treatment reporting the highest quality of life.

CONCLUSIONS

Home-based therapy was associated with better compliance compared with hospital-based therapy. The choice to adopt home-based therapy appeared to correlate with a high attack frequency. Home-based therapy is a valid treatment option for patients with C1-INH-HAE and should be offered to all such patients, and especially to those with high attack frequency.

Training hereditary angioedema patients to self-administer intravenous C1 esterase inhibitor concentrate

Hereditary angioedema (HAE) is a rare disorder that causes periodic attacks of sometimes painful swelling that may affect any organ system. HAE results in significant morbidity and diminished quality of life and requires patients to seek urgent medical care. HAE can be treated with C1 esterase inhibitor concentrate (C1-INH), icatibant, and ecallantide. Recent consensus guidelines recommend that all HAE patients be considered for training in self-administration of therapy to treat acute attacks or to prevent attacks. Many patients have safely and successfully self-administered intravenous infusions of C1-INH, resulting in rapid treatment, shortened attacks, and improved quality of life. With proper patient selection and adequate guidance and follow-up, self-administered C1-INH therapy is a viable and favorable option to treat HAE, particularly in patients with a moderate to high frequency of attacks.

Self-administered C1 esterase inhibitor concentrates for the management of hereditary angioedema: usability and patient acceptance

Hereditary angioedema (HAE) is a rare genetic disease characterized by episodic subcutaneous or submucosal swelling. The primary cause for the most common form of HAE is a deficiency in functional C1 esterase inhibitor (C1-INH). The swelling caused by HAE can be painful, disfiguring, and life-threatening. It reduces daily function and compromises the quality of life of affected individuals and their caregivers. Among different treatment strategies, replacement with C1-INH concentrates is employed for on-demand treatment of acute attacks and long-term prophylaxis. Three human plasma-derived C1-INH preparations are approved for HAE treatment in the US, the European Union, or both regions: Cinryze(®), Berinert(®), and Cetor(®); however, only Cinryze is approved for long-term prophylaxis. Postmarketing studies have shown that home therapy (self-administered or administered by a caregiver) is a convenient and safe option preferred by many HAE patients. In this review, we summarize the role of self-administered plasma-derived C1-INH concentrate therapy with Cinryze at home in the prophylaxis of HAE.

The safety of treatments for angioedema with hereditary C1 inhibitor deficiency

INTRODUCTION

Angioedema is a localized and self-limiting edema of the subcutaneous and submucosal tissue. Hereditary angioedema with C1 inhibitor deficiency (C1-INH-HAE) is the best characterized form of hereditary angioedema. In C1-INH-HAE, the reduced plasma levels of C1-INH cause instability of the contact system with release of bradykinin, the key mediator of angioedema. C1-INH-HAE is characterized by recurrent skin swelling, abdominal pain, and potentially life-threatening upper airways obstruction. Knowledge of the molecular mechanisms leading from C1-INH deficiency to angioedema allowed the development of several therapies.

AREAS COVERED

The aim of this review article is to discuss the safety of currently available treatments of C1-INH-HAE. The authors give an insight on the mechanism of action and safety profile of drugs for treatment of acute attacks and for short- and long-term prophylaxis. Evidence from systematic reviews, clinical trials, retrospective studies, and case reports is summarized in this review.

EXPERT OPINION

C1-INH-HAE is a disabling, life-threatening condition that lasts life-long. Different therapeutic approaches with different drugs provide significant benefit to patients. Safety profiles of these therapies are critical for optimal therapeutic decision and need to be known by C1-INH-HAE treating physicians for appropriate risk/benefit evaluation.

Plasma-derived C1-INH for managing hereditary angioedema in pediatric patients: A systematic review

Presently, medications approved for children with Hereditary Angioedema (HAE) are extremely limited. This is especially the case for children under 12 years of age. For this reason we reviewed and summarized the data on treatment of children with HAE. Available data indicate that plasma derived C1-inhibitor is a safe, effective treatment option for HAE in pediatric patients, including those below 12 years of age. Other therapies are also appear safe for the under 12 year of age, but less data are available. Importantly, home-based treatment of HAE in this age group appears to be safe and effective and can improve quality of life. These findings support current HAE consensus guidelines which strongly recommend the use of plasma derived C1-inhibitor as a first-line treatment in children and encourage home and self-treatment.

Hereditary angioedema: children should be considered for training in self-administration

Hereditary angioedema is an inherited disease that causes periodic swelling attacks, which can be life threatening and have a major effect on a patient's life. Studies have shown that home therapy for angioedema reduces disease severity, leads to faster relief of symptoms, and improves quality of life. Most studies have been conducted in adults. We report a 13-year-old boy who quickly learned self-administration, which resulted in reduced frequency and severity of attacks. The aim of this report is to emphasize that children should be considered for self-administration training and that the process does not have to be long or complicated.

The effect of weight on the efficacy and safety of C1 esterase inhibitor concentrate for the treatment of acute hereditary angioedema

BACKGROUND

Despite the worldwide obesity epidemic, there have been very few studies investigating the influence of body weight on treatment dosing and outcomes in patients with hereditary angioedema (HAE).

OBJECTIVE

The purpose of this analysis was to determine whether the standard weight-based dosing recommendation of C1 esterase inhibitor (C1-INH) concentrate (20 IU/kg) is adequate in HAE patients with a high body mass index (BMI).

METHODS

Data from patients treated for HAE attacks with 20 IU/kg of C1-INH concentrate were retrospectively analyzed from the open-label IMPACT2 study (International Multicenter Prospective Angioedema C1-INH Trial). Patients were categorized according to BMI as being normal body weight, overweight, or obese. Efficacy end points were time to onset of symptom relief and time to complete resolution of symptoms. The safety profile was evaluated according to adverse events occurring within 7 to 9 days of treatment.

RESULTS

Of 57 patients, 24 (42%) were of normal body weight, 20 (35%) were overweight, and 13 (23%) were obese. Median (95% CI) time to onset of symptom relief was 0.37 hour (0.29-0.57) in normal-weight patients, 0.48 hour (0.39-0.53) in overweight patients, and 0.58 hour (0.41-0.94) in obese patients. Median time (95% CI) to complete resolution of symptoms was 15.2 hours (9.3-23.2) in normal-weight patients, 22.6 hours (11.3-44.6) in overweight patients, and 11.0 hours (5.6-23.6) in obese patients (differences not significant). There were no relevant differences in the incidence of adverse events in normal-weight patients (54%), overweight patients (30%), and obese patients (54%).

CONCLUSIONS

Treatment of HAE attacks with weight-based doses of C1-INH concentrate provided reliable treatment response, regardless of body weight, in these patients with HAE.

A consensus parameter for the evaluation and management of angioedema in the emergency department

Despite its relatively common occurrence and life-threatening potential, the management of angioedema in the emergency department (ED) is lacking in terms of a structured approach. It is paramount to distinguish the different etiologies of angioedema from one another and more specifically differentiate histaminergic-mediated angioedema from bradykinin-mediated angioedema, especially in lieu of the more novel treatments that have recently become available for bradykinin-mediated angioedema. With this background in mind, this consensus parameter for the evaluation and management of angioedema attempts to provide a working framework for emergency physicians (EPs) in approaching the patient with angioedema in terms of diagnosis and management in the ED. This consensus parameter was developed from a collaborative effort among a group of EPs and leading allergists with expertise in angioedema. After rigorous debate, review of the literature, and expert opinion, the following consensus guideline document was created. The document has been endorsed by the American College of Allergy, Asthma & Immunology (ACAAI) and the Society for Academic Emergency Medicine (SAEM).

C1 inhibitor concentrate treatment of multiple laryngeal attacks in a 53-year-old woman with hereditary angioedema

This report describes a woman who experienced a high number of laryngeal hereditary angioedema (HAE) attacks during her participation in the IMPACT2 clinical trial of C1-INH concentrate. A 53-year-old caucasian female with a 31-year history of type 1 HAE experienced 16 laryngeal HAE attacks between 3 August 2006 and 23 February 2010, 15 of which were severe. All laryngeal attacks were successfully treated with C1-INH 20 U/kg, with a median onset of relief of 14 min and median time to complete resolution of symptoms of 20 h, and no need for redosing. The reliable success of C1-INH for these potentially fatal events is reassuring for both patients and prescribers.

Effect of time to treatment on response to C1 esterase inhibitor concentrate for hereditary angioedema attacks

BACKGROUND

C1 esterase inhibitor (C1-INH) concentrate is well established as effective therapy for hereditary angioedema (HAE). It is thought that treatment of an acute HAE attack with C1-INH as early as possible improves efficacy, but there are limited data from prospective studies supporting this recommendation.

OBJECTIVE

To assess the effect of time to treatment (<6 vs ≥6 hours after start of an attack) with 20 U/kg of C1-INH concentrate on efficacy.

METHODS

A post hoc analysis of time to treatment after start of an attack was performed for 2 studies with C1-INH concentrate: International Multicenter Prospective Angioedema C1-INH Trial (IMPACT) 1 (randomized, placebo-controlled) and IMPACT 2 (open-label, uncontrolled extension). Because of differences in study design, the data sets were analyzed separately. IMPACT 1 data were analyzed using Cox regression with hazard ratios (HRs). For IMPACT 2 data, linear regression was applied to evaluate whether earlier treatment leads to faster recovery. Descriptive statistics for treatment response were calculated for both studies.

RESULTS

In IMPACT 1, treatment with C1-INH within less than 6 hours after start of an attack resulted in considerably shorter times to onset of symptom relief (HR, 3.36) and complete resolution (HR, 4.30) vs placebo. The benefit of C1-INH compared with placebo was reduced when administered after 6 or more hours (HRs, 1.18 for times to onset of symptom relief and 1.61 for complete resolution). Analysis of IMPACT 2 data indicated slower complete resolution of symptoms with later start of treatment.

CONCLUSION

Early treatment with C1-INH (<6 hours) provides a better treatment response than late treatment (≥6 hours), supporting the international recommendation to treat HAE attacks as early as possible.

TRIAL REGISTRATION

ClinicalTrials.gov Identifiers: NCT00168103 and NCT00292981.

Review of recent guidelines and consensus statements on hereditary angioedema therapy with focus on self-administration

Consensus meetings and the resulting recommendations shape treatment choices in rare diseases such as hereditary angioedema (HAE) because they combine the experience of prescribing physicians and the patients who are receiving therapy. Self-administration of HAE therapy was recognised as a potential treatment option in the first consensus publication in 2003. Recent studies have confirmed that self-administration of therapy resolves attacks quickly, safely and minimises burden of disease; however, the discovery of inconsistent treatment approaches is a concern and warrants investigation into the barriers that prevent adherence with current recommendations.