Hereditary Angioedema in Women

The Disease Burden of Hereditary Angioedema: Insights from a Survey in French-Canadians from Quebec

Background

Limited data are available on the clinical profile and disease burden of hereditary angioedema (HAE) in Canadians.

Objective

This study aimed to assess HAE disease characteristics and the burden of disease in Canadians with HAE types I, II, and normal levels of C1 inhibitor (nC1-INH).

Materials and Methods

A 46-item patient survey evaluating clinical characteristics and burden of disease was developed and disseminated by the HAE patient organization Angio-oédeme héréditaire du Québec in Quebec, Canada, from May 2019 to February 2020. The survey received Research Review Board ethics approval.

Results

In the 35 respondents, HAE type I was the most common (46%), followed by nC1-INH (43%). Female participants were significantly younger at first symptom presentation than males (p=0.04). Prior to diagnosis, 69% of participants underwent unnecessary treatments and procedures, with a 10-year delay between first symptoms and diagnosis. Before starting the current treatment, 42% of participants experienced weekly HAE attacks. Most participants identified experiencing attacks in the abdomen (89%), followed by the larynx (66%), feet (66%), hands (63%), and face (63%). Most attacks were severe or moderate, yet almost half of patients waited >1 hr before getting medical attention at their last emergency department (ED) visit. HAE was associated with decreased health-related quality of life, leading to significant functional impairment in personal and professional life. As compared to HAE type I/II, patients with HAE nC1-INH were treated more often with tranexamic acid for long-term prophylaxis, and their condition was less controlled, resulting in more attacks and ED visits.

Conclusion

HAE manifests in this patient population as frequent moderate-to-severe attacks and a high disease burden; the HAE subtype may differentially affect care requirements. There is an urgent need for increased awareness and education on HAE among treating physicians.

National survey on clinical and genetic characteristics of patients with hereditary angioedema in Latvia

BACKGROUND

Hereditary angioedema (HAE) is a rare and life-threatening inborn error of immunity. HAE is mostly caused by pathogenic variations in the serine protease inhibitor gene 1 (SERPING1), leading to deficient or dysfunctional C1-inhibitor (C1-INH), overproduction of bradykinin, and development of recurrent subcutaneous and/or submucosal oedema. The prevalence of HAE is 1 in 50,000 - 100000 people worldwide. We aimed to describe the clinical features and genetic spectrum of hereditary angioedema with C1-INH deficiency (C1-INH-HAE) in Latvia.

METHODS

All patients from Latvia diagnosed with HAE (types I/II) from 2006 to March 2022 were included in the study. Laboratory tests and clinical data were analysed, and genetic tests with Sanger sequencing and whole genome sequencing were performed.

RESULTS

The study identified 10 C1-INH-HAE patients (nine females, one male) from eight families. The point prevalence of HAE in Latvia is 0.53 per 100 000 inhabitants. Of all patients, seven (70%) had HAE type I and three (30%) had HAE type II. The median age of patients was 54 years and the median age at onset of symptoms was 15 years. A significant delay (median 20.5 years) until diagnosis was observed, and 60% of patients had a positive family history of angioedema. All HAE patients have been hospitalised a median two times during their lifetime. Skin (100%), abdominal (80%), and airway (80%) oedema were the most frequent symptoms. Triggering factors (60%) and prodromal symptoms (90%) were referred. Attacks were severe in 50% of patients, moderate in 10%, and mild in 40%. Pathogenic variations of SERPING1 were identified in eight patients (six families), confirming the diagnosis molecularly. In two patients (two families), no pathogenic variations in the genes were found even after whole genome sequencing.

CONCLUSIONS

Current data shows a significant delay and clear underdiagnosis of HAE in Latvia. Higher awareness and better information and communication between doctors would improve the diagnosis and management of HAE; as would screening of family members, patients with recurrent angioedema unresponsive to antihistamines and glucocorticoids, and patients with recurrent episodes of severe, unexplained abdominal pain.

[Hereditary angioedema and its new treatments: An update]

Hereditary angioedema, with or without deficient C1 inhibitor level or function, is a rare disease characterized by recurrent attacks of noninflammatory subcutaneous and/or submucosal edema. It may be life-threatening and substantially affects quality of life. Attacks may be spontaneous or induced, in a setting of emotional stress, by infections or physical trauma, in particular. As the key mediator is bradykinin, this angioedema does not respond to the usual treatments of mast cell-mediated angioedema (antihistamines, corticosteroids, adrenaline), which is much more frequent. Therapeutic management of hereditary angioedema first consists in treating severe attacks with a selective B2 bradykinin receptor antagonist or a C1 inhibitor concentrate. The latter or an attenuated androgen (danazol) can be used for short-term prophylaxis. Therapeutic solutions conventionally proposed for long-term prophylaxis (danazol, antifibrinolytics [tranexamic acid], C1 inhibitor concentrate) vary in efficacy and/or pose problems of safety or ease of use. Kallikrein inhibitors (subcutaneous lanadelumab, oral berotralstat) recently made available as disease-modifying treatment constitute an important advance in long-term prophylaxis of hereditary angioedema attacks. The advent of these new drugs is accompanied by a new ambition for patients: optimize control of the disease and thereby minimize its impact on quality of life.

Trends in Treatments With Disease-Specific and Interfering Drugs in Patients With Hereditary Angioedema in Sweden

BACKGROUND

Hereditary angioedema (HAE) is caused by low levels of or defects in C1 inhibitor. Although disease activity may be modified by prophylaxis, emergency treatment, treatment for comorbidities, and oral contraceptives, the extent of their use is unclear.

OBJECTIVE

To investigate trends in the use of disease-specific and interfering drugs in patients with HAE compared with the general population in Sweden.

METHODS

In a nationwide, longitudinal study, 239 patients with HAE and 2 383 controls were compared with the Prescribed Drug Register (2005-2019). These data reflect rates of dispensed prescriptions from pharmacies in Sweden.

RESULTS

Attenuated androgens were used by approximately 10% of patients with HAE. The number of individuals treated with prophylactic plasma-derived C1 inhibitor increased during this period to reach almost 25% in men and 35% in women in 2019. Tranexamic acid was prescribed to 5% to 15% of patients, primarily children and young adults. Rates of prescriptions for icatibant, an emergency medication, showed a steady increase since its introduction in 2010, in particular among middle-aged women, suggesting poorly controlled disease. The use of diuretics, calcium channel blockers, and gestagens was more common in patients with HAE than in controls, whereas angiotensin-converting enzyme inhibitors were rarely collected.

CONCLUSIONS

Despite concerns regarding side effects, approximately 10% of patients with HAE received attenuated androgens for long-term prophylaxis. The common use of emergency medication also suggests poorly controlled disease in many patients, highlighting the need for increased focus on prophylactic treatment.

The impact of puberty on the onset, frequency, location, and severity of attacks in hereditary angioedema due to C1-inhibitor deficiency: A survey from the Italian Network for Hereditary and Acquired Angioedema (ITACA)

Introduction

Hereditary angioedema due to C1-inhibitor deficiency is influenced by hormonal factors, with a more severe course of disease in women. Our study aims to deepen the impact of puberty on onset, frequency, location and severity of attacks.

Methods

Retrospective data were collected through a semi-structured questionnaire and shared by 10 Italian reference centers of the Italian Network for Hereditary and Acquired Angioedema (ITACA).

Results

The proportion of symptomatic patients increased significantly after puberty (98.2% vs 83.9%, p=0.002 in males; 96.3% vs 68,4%, p<0.001 in females); the monthly mean of acute attacks was significantly higher after puberty, and this occurred both in females (median (IQR) = 0.41(2) in the three years before puberty vs 2(2.17) in the three years after, p<0.001) and in males (1(1.92) vs 1.25(1.56) respectively, p<0.001). The increase was greater in females. No significant differences were detected in attack location before and after puberty.

Discussion

Overall, our study confirms previous reports on a more severe phenotype in the female gender. Puberty predisposes to increased numbers of angioedema attacks, in particular in female patients.

Safety of medications for hereditary angioedema during pregnancy and lactation

INTRODUCTION

Hereditary Angioedema (HAE) attacks show an increased frequency and severity for pregnant and lactating females secondary to the hormonal changes. The diagnosis and management of HAE in pregnant and lactating females pose a challenge for physicians due to the rarity of the disease and the paucity of the data for specific management.

AREAS COVERED

In this manuscript, we discuss the diagnosis and special presentation of HAE types 1 and 2 in pregnant and lactating females, including acute management, short-term prophylaxis, long-term prophylaxis, and drugs that should be avoided. Relevant publications were found through key word search of papers indexed in both Google Scholar and PubMed on 1 July 2022.

EXPERT OPINION

Treatment of HAE in the past has been mainly provided by experts; however, with more medications and an increasing number of patients, knowledge of how to care for HAE patients during pregnancy and lactation is important to review. Despite approval of additional medications in many countries, plasma-derived C1-inhibitor remains the drug of first choice for treatment in this unique population. Additional research is needed to increase safe access to other therapy options. We hope that future clinical studies, registries, and databases will shed additional light on this subject.

Considerations in the management of hereditary angioedema due to C1-INH deficiency in women of childbearing age

Hereditary angioedema (HAE) is a rare, autosomal disorder that manifests with unpredictable episodes of severe swelling of the skin and mucous membranes. These attacks can be highly disfiguring and range in severity from mild to-in cases of airway swelling-life-threatening. Fluctuations in female sex hormones-such as the changes that occur during puberty, menses, contraceptive use, pregnancy, and menopause-can all affect the frequency and severity of HAE attacks. Disease management decisions for women of childbearing age may be more complex and require additional considerations since they could develop complications related to contraception, pregnancy, labor, delivery, and lactation. In addition, some HAE treatment options are contraindicated during pregnancy. Discussions about medications used to treat HAE should include a risk-benefit assessment of the woman's health status, her preferences, and other factors that are relevant to the choice of therapy. Planning prophylactic therapies that are effective and safe before, during, and after pregnancy can prevent gaps in treatment, ensure continuity of care, and reduce both disease burden and risk of adverse fetal outcomes. The 2020 US Hereditary Angioedema Association (HAEA) Medical Advisory Board and 2021 World Allergy Organization/European Academy of Allergy and Immunology (WAO/EAACI) Guidelines outline key considerations for managing HAE in females of childbearing age (15-45 years), with the goal of improving treatment efficacy and safety for this cohort of patients. Treatment decisions made in a collaborative manner involving the patient, HAE specialist and obstetric/gynecologic specialist, is the best approach to ensure optimal HAE management and safety in this patient population.

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 murine in vivo model for acute hereditary angioedema attacks

Hereditary Angioedema (HAE) is a rare genetic disease generally caused by deficiency or mutations in the C1-inhibitor gene, SERPING1, a member of the Serpin family. HAE results in acute attacks of edema, vasodilation, GI pain and hypotension. C1INH is a key inhibitor of enzymes controlling complement activation, fibrinolysis and the contact system. In HAE patients, contact system activation leads to uncontrolled production of bradykinin, the vasodilator responsible for the characteristic symptoms of HAE. In this study, we present the first physiological in vivo model to mimic acute HAE attacks. We evaluate hypotension, one of the many hallmark symptoms of acute HAE attacks using Serping1 deficient mice (serping1−/−) and implanted telemetry. Attacks were induced by IV injection of a silica nanoparticle (SiNP) suspension. Blood pressure was measured in real time, in conscious and untethered mice using implanted telemetry. SiNP injection induced a rapid, reversible decrease in blood pressure, in the presence of angiotensin converting enzyme (ACE) inhibition. We also demonstrate that an HAE therapeutic, ecallantide, can prevent HAE attacks in this model. The in vivo murine model described here can facilitate the understanding of acute HAE attacks, support drug development and ultimately contribute to improved patient care.

Impact of anxiety, stress and depression related to COVID-19 pandemic on the course of hereditary angioedema with C1-inhibitor deficiency

Background

Hereditary angioedema (HAE) attacks can be provoked with psychological factors. The aim of this study was to assess the effects of anxiety, depression and stress related to COVID‐19 pandemic on disease activity of HAE patients during the quarantine period (QP) and the return to normal period (RTNP).

Methods

This study was conducted between March 2020 and September 2020 in four allergy centres. Demographic, clinical features and mental health status were evaluated in QP (from March to the beginning of June) and RTNP (from June to the beginning of September) applied by the government. The 10‐point visual analogue scale (VAS10) was used to define the severity of HAE attacks. Depression, Anxiety and Stress Scales‐21 (DASS‐21) and Fear of COVID‐19 (FC‐19) scale were performed to assess mental health status.

Results

139 HAE patients were included in the study. In QP, median attack numbers and median VAS10 scores were 5 (min‐max: 0–45) and 6 (min‐max: 0–10), respectively. HAE attack numbers, DASS‐21 stress, anxiety, depression and total DASS‐21 scores, and FC‐19 scores were higher in QP than RTNP (p = 0.001, p < 0.001, p = 0.001, p < 0.001, p < 0.001, p < 0.001, respectively). However, there was no difference in attack severity scores between the two periods (p > 0.05).

Conclusions

This study revealed that the restriction measures during COVID‐19 outbreak cause an increase in the number of HAE attacks in relation to anxiety, depression, stress and fear of COVID‐19 pandemic. Therefore, it is important to provide psychological support to HAE patients during the pandemic.

Hormonal Effects on Urticaria and Angioedema Conditions

Women appear to be more frequently affected with urticaria and angioedema. Sex hormones are believed to have an important mechanistic role in regulating pathways involved in these conditions. This effect is likely nonspecific for chronic spontaneous urticaria (CSU) or many forms of angioedema (AE), because many other chronic diseases such as asthma are also affected by sex hormones. The role of sex hormones has been better elucidated for hereditary AE, because they have been shown to have multiple effects including upregulation of FXII, an important activator of the kallikrein pathway. However, their role in the underlying pathogenesis for CSU is less clear. Autoimmunity is clearly linked to CSU, which is more common in women. This suggests that sex hormones could act as adjuvants in activating or upregulating autoimmune pathways. The purpose of this review is to discuss in detail the role of sex hormones in CSU and AE and how a better understanding of the impact hormones has on these conditions might lead to new treatment advancements with better clinical outcomes.

How Angioedema Quality of Life Questionnaire Can Help Physicians in Treating C1-Inhibitor Deficiency Patients?

The Angioedema Quality of Life Questionnaire (AE-QoL) is an angioedema (AE)-specific validated questionnaire, which surveys the quality of life of diagnosed patients. The questionnaire has been used in multiple clinical trials. Our aim was to investigate how the questionnaire can assist physicians in the everyday practice of following up and managing C1-inhibitor deficiency patients. In a prospective trial conducted in our center between 2016 and 2018, 125 hereditary angioedema and 10 diagnosed with acquired angioedema completed an AE-QoL during their annual follow-up visit. Laboratory indices (i.e., complement levels) were obtained for each patient. Statistical analysis comparing clinical data with QoL parameters was performed. Results of the analysis show that AE-QoL total score and number of AE attacks per year correlated well (r = 0.47; p < 0.0001). Women reached higher AE-QoL total score values than men, over a 3-year period (p = 0.0014). The highest AE-QoL total scores were reached by the 41–60-year age group; we obtained a similar result, when analyzing the four domains. No correlation was found between the AE-QoL total score and complement parameters. Patients with a negative correlation between AE-QoL total score and number of AE attacks had a positive correlation with psychologic attributes like fatigue/mood and fears/shame domains. Patients that acquired HAE showed a significant correlation between the annual number of AE attacks and the AE-QoL total scores (r = 0.46; p < 0.0001). The study establishes the use of AE-QoL as a clinical tool for follow-up which can help in the complex assessment of both hereditary and acquired HAE patients, and help to develop better therapeutic strategies.

Short-term Prophylaxis for Delivery in Pregnant Women with Hereditary Angioedema with Normal C1-Inhibitor

OBJECTIVE

 To verify the efficacy of short-term prophylaxis for vaginal or cesarean section childbirth with plasma-derived C1-inhibitor concentrate in pregnant women. They should have hereditary angioedema (HAE) and normal plasma C1-inhibitor.

METHODS

 Case report of pregnant women diagnosed with HAE with normal C1-inhibitor who had been treated with intravenous C1-inhibitor concentrate for prophylaxis of angioedema attacks when hospitalized for delivery. The exon 9 of the Factor 12 (F12) genotyping gene was performed by automatic sequencing in all patients.

RESULTS

 Three cases of pregnant women with HAE with normal serum level of C1-inhibitor are reported. The genetic test detected the presence of a pathogenic mutation in the F12 gene. Deliveries occurred uneventfully and patients had no HAE symptoms in the following 72 hours.

CONCLUSION

 C1-inhibitor concentrate could be useful to prevent angioedema attacks during and after delivery.

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.

Experience with Intravenous Plasma-Derived C1-Inhibitor in Pregnant Women with Hereditary Angioedema: A Systematic Literature Review

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.

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.

Lanadelumab for the Prophylactic Treatment of Hereditary Angioedema with C1 Inhibitor Deficiency: A Review of Preclinical and Phase I Studies

Hereditary angioedema (HAE) with C1 esterase inhibitor (C1-INH) deficiency (C1-INH-HAE) is a rare disease characterized by diminished levels or dysfunctional activity of C1-INH, leading to dysregulated plasma kallikrein activity within the kallikrein-kinin pathway. Symptoms manifest as painful, potentially life-threatening swelling of subcutaneous tissues throughout the body and/or submucosal edema in the upper airway or gastrointestinal tract. Attacks recur with unpredictable frequency, intensity, and duration, placing a heavy burden on patients' daily lives. Despite improved availability of medications for on-demand treatment during attacks and prophylaxis of future attacks, unmet needs remain. Lanadelumab, a fully human monoclonal antibody, may help address some of the limitations of existing prophylactic options (e.g., the need for intravenous administration or frequent dosing). Preclinical studies demonstrate that it is highly potent and specifically inhibits plasma kallikrein, and findings from phase Ia and Ib studies suggest this agent is well tolerated and provides sustained inhibition of plasma kallikrein, allowing for less frequent dosing. The phase III HELP Study (NCT02586805) evaluating the efficacy and safety of lanadelumab in preventing HAE attacks has been completed, and its open-label extension (NCT02741596) is ongoing. Lanadelumab is now approved in the USA and Canada for prophylaxis to prevent attacks of HAE in patients aged ≥ 12 years. This review provides an overview of the discovery and clinical development of lanadelumab, from preclinical through phase Ib studies, characterizing its safety/tolerability, efficacy, and pharmacokinetic and pharmacodynamic profiles. It also highlights how this agent may positively impact clinical care of patients with C1-INH-HAE.

Long-term prophylaxis therapy in patients with hereditary angioedema with C1 inhibitor deficiency

OBJECTIVE

To review the criteria for long-term prophylaxis therapy in patients with hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE), describe how these criteria have evolved over time, and anticipate how criteria may change in the future with the availability of new C1-INH-HAE treatment options.

DATA SOURCES

Treatment guidelines, consensus statements, and expert reviews.

STUDY SELECTIONS

Manuscripts that described long-term prophylaxis therapy in patients with C1-INH-HAE were selected.

RESULTS

Historically, patients with C1-INH-HAE were considered to be candidates for long-term prophylaxis therapy if they had at least 1 attack per month, had at least 5 days of disability per month because of C1-INH-HAE, or did not sufficiently respond to on-demand treatment. More recently, guidelines and reviews state that thresholds of number of attacks or days of disability are arbitrary and that treatment plans should be individualized to the patient's needs. Furthermore, all patients should have a comprehensive management plan that is reviewed periodically and should have at least 2 doses of on-demand treatment available. Prophylaxis therapy should be discussed as a potential treatment option for each patient; however, the decision for its use will depend on the patient's individual needs and the course of their symptoms.

CONCLUSION

The criteria for long-term prophylaxis therapy in C1-INH-HAE have changed with the recognition that treatments should be individualized to the patient's needs and with the availability of new medications that have more favorable benefit-risk profiles, are easier to use, and improve patients' quality of life.

In Vitro Fertilization Using Luteinizing Hormone-Releasing Hormone Injections Resulted in Healthy Triplets without Increased Attack Rates in a Hereditary Angioedema Case

Hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE) is a rare, autosomal dominant disorder. The management of pregnant patients with C1-INH-HAE is a challenge for the physician. Intravenous plasma-derived nanofiltered C1-INH (pdC1INH) is the only recommended option throughout pregnancy, postpartum, and breastfeeding period. In order to increase pregnancy rates, physicians use fertilization therapies increasing endogen levels of estrogens. Therefore, these techniques can provoke an increase in the number and severity of edema attacks in C1-INH-HAE. Our patient is a 32-year-old female, diagnosed with C1-INH-HAE type 1 since 2004. She had been taking danazol 50–200 mg/day for 9 years. Due to her pregnancy plans in 2013, danazol was discontinued. PdC1INH was prescribed regularly for prophylactic purpose. Triplet pregnancy occurred by in vitro fertilization using luteinizing hormone-releasing hormone (LHRH) injections. In our patient, LHRH injections were done four times without causing any severe attack during in vitro fertilization. Angioedema did not worsen during pregnancy and delivery due to the prophylactic use of intravenous pdC1INH in our patient. According to the attack frequency and severity, there was no difference between the three pregnancy trimesters. To our knowledge, this is the first published case of C1-INH-HAE receiving in vitro fertilization therapies without any angioedema attacks during pregnancy and delivery and eventually having healthy triplets with the prophylactic use of intravenous pdC1INH.

Assessment of 105 Patients with Angiotensin Converting Enzyme-Inhibitor Induced Angioedema

Objective. To asses a cohort of 105 consecutive patients with angiotensin converting enzyme-inhibitor induced angioedema with regard to demographics, risk factors, family history of angioedema, hospitalization, airway management, outcome, and use of diagnostic codes used for the condition. Study Design. Cohort study. Methods. This was a retrospective cohort study of 105 patients with angiotensin converting enzyme-inhibitor induced angioedema in the period 1995-2014. Results. The cohort consisted of 67 females and 38 males (F : M ratio 1.8), with a mean age of 63 [range 26-86] years. Female gender was associated with a significantly higher risk of angiotensin converting enzyme-inhibitor induced angioedema. 6.7% had a positive family history of angioedema. Diabetes seemed to be a protective factor with regard to angioedema. 95% experienced angioedema of the head and neck. 4.7% needed intubation or tracheostomy. 74 admissions took place during the study period with a total of 143 days spent in the hospital. The diagnosis codes most often used for this condition were "DT783 Quincke's oedema" and "DT78.4 Allergy unspecified". Complement C1 inhibitor was normal in all tested patients. Conclusion. Female gender predisposes to angiotensin converting enzyme-inhibitor induced angioedema, whereas diabetes seems to be a protective factor.

HAE Pathophysiology and Underlying Mechanisms

Remarkable progress in understanding the pathophysiology and underlying mechanisms of hereditary angioedema has led to the development of effective treatment for this disorder. Progress in three separate areas has catalyzed our understanding of hereditary angioedema. The first is the recognition that HAE type I and type II result from a deficiency in the plasma level of functional C1 inhibitor. This observation has led to a detailed understanding of the SERPING1 mutations responsible for this deficiency as well as the molecular regulation of C1 inhibitor expression and function. The second is that the fundamental cause of swelling is enhanced contact system activation leading to increased generation of bradykinin. Substantial progress has been made in defining the parameters regulating bradykinin generation and catabolism as well as the receptors that transduce the biologic effects of kinins. The third is the understanding that tissue swelling in hereditary angioedema primarily involves the function of endothelial cell adherens junctions. This knowledge is driving increased attention to the role of endothelial biology in determining disease activity in hereditary angioedema. While there has been considerable progress made, large gaps still remain in our knowledge. Important areas that remain poorly understood include the factors that lead to very low plasma functional C1 inhibitor levels, the triggers of contact system activation in hereditary angioedema, and the role of the bradykinin B1 receptor. The phenotypic variability of hereditary angioedema has been extensively documented but never understood. The mechanisms discussed in this chapter likely contribute to this variability. Future progress in understanding these mechanisms should provide new means to improve the diagnosis and treatment of hereditary angioedema.

Infections and edema

Infectious and inflammatory conditions of the head and neck may present with impaired airways. An understanding of the pathophysiology will allow for accurate diagnosis and prompt intervention. Preintervention discussion and planning by members of the airway team are crucial in developing a primary and backup plans for safely securing the airway.

Recombinant human C1 esterase inhibitor for the treatment of hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE)

The lack of C1 inhibitor function that results in excessive production of bradykinin causing the angioedema seen in hereditary angioedema (HAE) is well established. Several drugs have been developed to treat and prevent attacks in patients suffering from HAE due to C1 inhibitor deficiency (C1-INH-HAE). Plasma-derived C1INH has been used to replace the deficiency of C1 inhibitor (C1INH) and has been approved for both treatment of attacks and for prophylactic therapy to prevent attacks. Plasma kallikrein inhibitor (ecallantide) and bradykinin receptor antagonist (icatibant) are both effective for treatment of acute attacks, but their short half-life limits the use for prophylaxis. Androgens, in particular danazol, are effective for long-term prophylaxis, but adverse event profile can limit its use. Recombinant C1 inhibitor derived from transgenic rabbits has recently been approved for use in treatment of C1-INH-HAE attacks and is effective and appears safe with minimal adverse event profile.

[Diagnosis of hereditary angioedema]

Hereditary angioedema is a rare disease, potentially life-threatening. It requires a specific treatment. Angioedema without wheals associated with abdominal attacks are very specific of this disease. Antigenemy and functional C1Inhibitor assays are necessary for the diagnosis. The hereditary angioedema with normal C1Inh (type III) is a diagnostic challenge. Bradykinin, secondary to kallikrein-kinin system activation is the key mediator of hereditary angioedema. Female are more symptomatic. Attacks can be induced by menstruations, pregnancies or contraceptive pills.

Management of hereditary angioedema in pregnant women: a review

THREE TYPES OF HEREDITARY ANGIOEDEMA (HAE) HAVE BEEN DESCRIBED

two are due to C1 inhibitor (C1-INH) deficiency (C1-INH-HAE types I and II) and one is characterized by normal C1-INH (nC1-INH-HAE). The management of pregnancy in patients with HAE is often a clinical challenge owing to potential worsening of the disease in relation to the physiological increase in estrogens and the limited treatment options. This review addresses the potential influence of pregnancy on the clinical severity of hereditary angioedema and the management of this disease during pregnancy with currently available treatments.