Food as a trigger for abdominal angioedema attacks in patients with hereditary angioedema

Phenotypic and molecular characterization of the largest worldwide cluster of hereditary angioedema type 1

Hereditary angioedema type 1 (HAE1) is a rare, genetically heterogeneous, and autosomal dominant disease. It is a highly variable, insidious, and potentially life-threatening condition, characterized by sudden local, often asymmetric, and episodic subcutaneous and submucosal swelling, caused by pathogenic molecular variants in the SERPING1 gene, which codes for C1-Inhibitor protein. This study performed the phenotypic and molecular characterization of a HAE1 cluster that includes the largest number of affected worldwide. A geographically HAE1 cluster was found in the northeast Colombian department of Boyaca, which accounts for four unrelated families, with 79 suspected to be affected members. Next-Generation Sequencing (NGS) was performed in 2 out of 4 families (Family 1 and Family 4), identifying the variants c.1420C>T and c.1238T>G, respectively. The latter corresponds to a novel mutation. For Families 2 and 3, the c.1417G>A variant was confirmed by Sanger sequencing. This variant had been previously reported to the patient prior to the beginning of this study. Using deep-learning methods, the structure of the C1-Inhibitor protein, p.Gln474* and p.Met413Arg was predicted, and we propose the molecular mechanism related to the etiology of the disease. Using Sanger sequencing, family segregation analysis was performed on 44 individuals belonging to the families analyzed. The identification of this cluster and its molecular analysis will allow the timely identification of new cases and the establishment of adequate treatment strategies. Our results establish the importance of performing population genetic studies in a multi-cluster region for genetic diseases.

Dietary and physical trigger factors in hereditary angioedema: Self-conducted investigation and literature overview

BACKGROUND

In hereditary angioedema (HAE), numerous factors are known to trigger an attack. The possible influence of diet or recreational sports has been given little consideration in studies. The aim of our work was to investigate the influence of nutrition and physical activity in patients with HAE at the Leipzig ACARE Center.

MATERIALS AND METHODS

Patients with HAE were given a self-designed questionnaire inquiring for family history, disease progression, and encountered burden due to HAE, current therapy, and disease control (angioedema control test (AECT)) as well as the influence of diet and/or recreational sports on HAE attacks.

RESULTS

Inclusion of 30 patients (23 female, 77%) with a mean age of 49.5 ± 16.9 years and mean body mass index of 25.1 ± 6.4 kg/m2. 60% received prophylactic treatment, and 37% received exclusively on-demand therapy. The mean AECT score was 10.9 ± 5.1 and patients reported 15.5 ± 26.9 days of absence due to HAE attacks in the last 12 months. 33% reported an association with food intake, in particular worsening of abdominal symptoms (n = 7), swelling of the extremities (n = 3), face, larynx, or genital area (n = 1 each). 70% reported regular exercise, most commonly cycling (n = 11), running or walking (n = 10), or strength training (n = 10). 62% reported a worsening of HAE due to recreational exercise.

CONCLUSION

Dietary factors and physical activity frequently led to an aggravation of HAE in our cohort and should be taken into consideration when counseling patients with regard to trigger avoidance.

Mast cell degranulation and bradykinin-induced angioedema - searching for the missing link

Initiation of the bradykinin generation cascade is responsible for the occurrence of attacks in some types of angioedema without wheals. Hereditary angioedema due to C1 inhibitor deficiency (HAE-C1-INH) is one such clinical entity. In this paper, we explore the existing evidence that mast cells (MCs) degranulation may contribute to the activation of the kallikrein-kinin system cascade, followed by bradykinin formation and angioedema. We present the multidirectional effects of MC-derived heparin and other polyanions on the major components of the kinin-kallikrein system, particularly on the factor XII activation. Although, bradykinin- and histamine-mediated symptoms are distinct clinical phenomena, they share some common features, such as some similar triggers and a predilection to occur at sites where mast cells reside, namely the skin and mucous membranes. In addition, recent observations indicate a high incidence of hypersensitivity reactions associated with MC degranulation in the HAE-C1-INH patient population. However, not all of these can be explained by IgE-dependent mechanisms. Mast cell-related G protein-coupled receptor-X2 (MRGPRX2), which has recently attracted scientific interest, may be involved in the activation of MCs through a different pathway. Therefore, we reviewed MRGPRX2 ligands that HAE-C1-INH patients may be exposed to in their daily lives and that may affect MCs degranulation. We also discussed the known inter- and intra-individual variability in the course of HAE-C1-INH in relation to factors responsible for possible variability in the strength of the response to MRGPRX2 receptor stimulation. The above issues raise several questions for future research. It is not known to what extent a prophylactic or therapeutic intervention targeting the pathways of one mechanism (mast cell degranulation) may affect the other (bradykinin production), or whether the number of mast cells at a specific body site and their reactivity to triggers such as pressure, allergens or MRGPRX2 agonists may influence the occurrence of HAE-C1-INH attacks at that site.

Hypersensitivity reactions amongst Hungarian Patients with Hereditary Angioedema due to C1-Inhibitor Deficiency

Background

In hereditary angioedema (HAE) due to C1-inhibitor deficiency (C1-INH-HAE), bradykinin-mediated submucosal and/or subcutaneous angioedema dominates the clinical picture. The deficiency of C1-inhibitor can lead to the over-activation of the complement system. Complement plays an important role in all types of hypersensitivity reactions. On the other hand, during the degranulation of mast cells, heparin is also released amongst other substances. Heparin can activate the plasma kinin-kallikrein system, leading to bradykinin generation. These observations suggest a possible connection between C1-INH-HAE and mast cell-mediated hypersensitivity reactions.

Objective

To assess the occurrence of hypersensitivity reactions in the Hungarian C1-INH-HAE population.

Methods

Patients filled out a questionnaire of 112 questions, either online or on paper. The questions were about hypersensitivity and C1-INH-HAE symptoms, the relation between these 2, general health, and demographic data. The study protocol was approved by the institutional review board of Semmelweis University, Budapest, and informed consent was obtained from the participants.

Results

One hundred and six patients (64 female, 42 male, median age 46 years) responded, with 63.2% having hypersensitivity. Hypersensitivity was provoked by pollen in 25.5% of patients, by contact sensitivity in 22.6%, by food in 21.7%, by insect sting in 19.8%, by pet in 15.1%, by drug in 14.2%, by dust mite in 5.7%, and by mold in 1.9%. In 11 patients, hypersensitivity symptoms appeared after the diagnosis of C1-INH-HAE. Six hypersensitive patients experienced improvement in their symptoms; 42 remained the same, but none experienced worsening after the diagnosis of C1-INH-HAE. In 7.8% of the hypersensitive patients, a C1-INH-HAE attack worsened the hypersensitivity symptoms, while 15.7% of the hypersensitive patients experienced a C1-INH-HAE attack provoked by contact with the provoking factor.

Conclusion

While 63.2% of our C1-INH-HAE patients have reported hypersensitivity symptoms, Eurostat's latest data puts the prevalence of self-reported allergies in Hungary at 19.3%. Since in our experience most Hungarian patients report hypersensitivity reactions as allergies, this may support a possible connection between the 2 diseases, but further molecular studies are needed.

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.

Triggers of Exacerbation in Chronic Urticaria and Recurrent Angioedema-Prevalence and Relevance

Patients with urticaria and angioedema often have triggers that cause an outbreak or a swelling episode or worsen their chronic condition. Exploring these factors with each patient may result in better understanding and control of their disease. Patients should be advised to avoid known triggers, if feasible, or prepare to prevent or control an exacerbation with appropriate pretreatment if avoidance is not possible. In this review, we describe and discuss a variety of factors for which there is evidence that they cause or exacerbate chronic spontaneous urticaria and angioedema. These potentially exacerbating factors include drugs, food additives, and naturally occurring pseudoallergens, mental stress, and trauma.

Gastrointestinal manifestations of angioedema: a potential area of misdiagnosis

Abdominal pain is one of the most common conditions leading people to the emergency department. An uncommon but well described cause of abdominal pain is angioedema of the gastrointestinal tract due to recurrent angioedema without wheals. Abdominal involvement is very common in hereditary angioedema (HAE), but it is also described in acquired angioedema and allergic forms. In patients with HAE, the involvement of gastrointestinal tract with resultant abdominal pain occurs in 43-93% of cases. Attacks can involve the entire gastrointestinal tract, such as the oropharynx, small intestine, colon, liver, or pancreas. Pain is the most common gastrointestinal symptom, and it may occur for many years even without cutaneous or respiratory symptoms. The case report we included in this article emphasizes the importance of accurate evaluation of personal and family history in patients with a long history of acute, severe, and unexplained abdominal pain, and it gives an example of how diagnostic delay may be longer if gastroenterological symptoms are the predominant clinical presentation. Furthermore, sometimes the simultaneous presence of concomitant gastrointestinal disorders and HAE may cause difficulties in differential diagnosis. Gastroenterologists and other physicians should add HAE to their list of potential causes of unexplained abdominal pain. The initiation of appropriate prophylaxis and treatment will prevent needless suffering and useless surgical and medical procedures.

Clinical profile of hereditary angioedema from a tertiary care centre in India

INTRODUCTION

Hereditary angioedema (HAE) is a clinical condition which could be fatal if not identified and managed appropriately. Knowledge of this condition is mostly confined to individual case reports and literature reviews in India. In this retrospective study we describe HAE cases which presented to a tertiary care centre in India over a period of three and half years.

MATERIALS AND METHODS

Clinical case records of forty-two HAE patients diagnosed based on clinical and laboratory features were accessed after due approval from the Ethics committee. C1 esterase inhibitor (C1 INH) and C4 levels were measured using nephelometry. All relevant data was entered into Microsoft EXCEL worksheet and analysed using simple statistical tools.

RESULTS

Among the 42 patients diagnosed as having HAE, 37 had low C1INH levels and were diagnosed to have type 1 HAE. The remaining 5 had normal C1 INH levels and were considered probable HAE based on family history and response to HAE specific treatment. The median age of onset of symptoms was 15 years (range 5-49) and median age at diagnosis, 27.5 years (range 5-55). The median delay in diagnosis was 10 years (range 1-27 years). Family history of HAE was observed in 52.6% and 29% reported deaths in the family with HAE like disease. Low dose androgens or tranexamic acid or both were prescribed in 64.2% of the patients. Orofacial edema was the commonest clinical presentation (76%) followed by edema of the extremities (38%), GI tract symptoms (19%) and genital involvement (11.9%).

CONCLUSION

Many cases of HAE may be going undetected in India. There is a need for clinical awareness and laboratory means to accurately identify and administer appropriate treatment.

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.

The natural course of hereditary angioedema in a Chinese cohort

Background

Hereditary angioedema (HAE) is a rare disease with potential life-threatening risks. To study the natural course of HAE under therapy-free conditions throughout patient life is essential for practitioners and patients to avoid possible risk factors and guide treatment.

Objectives

Describe the natural course of HAE and explore possible risk factors, providing new clues for guiding clinical prevention and treatment.

Methods

A web-based survey was conducted in 103 Chinese patients with type 1 HAE. Disease progression at different age stages was provided by each participant. The data for exploring the natural course of HAE composed of two parts: one came from the participants who had never adopted any prophylactic drug for HAE; the other was from the patients with a history of medication, but only the periods before they got confirmed diagnosis and received medications were analyzed. The demographic characteristics, lifestyles, disease severity, and family history were also collected.

Results

Among 103 patients, 14 (13.6%) had their first HAE attack before 10 years old and 51 (49.5%) between 10 and 19. The disease worsened in 83.3% of the patients in their twenties. The proportion of patients with symptoms alleviated increased after the age of 30 years old, but the disease maintained relatively severe in most cases before 50. The participants also reported 233 members shared similar symptoms of angioedema in their family and 30 had died of laryngeal edema with the median death age of 46 years old. The disease severity was not observed to be affected significantly by gender, BMI, alcohol or smoking.

Conclusions

We summarized HAE progression patterns under therapy-free conditions, showing the natural course of HAE development along with aging. Long-term prophylaxis and symptomatic treatment are recommended for all HAE patients, especially young and middle-aged and might be adjusted depending on the disease progression.

Air Pollution and Angioedema

OBJECTIVE

To identify environmental factors that may precipitate angioedema.

STUDY DESIGN

Case series with chart review.

SETTING

An urban tertiary care medical center.

SUBJECTS AND METHODS

After institutional review board approval was obtained, a chart review of all patients who presented to Temple University Hospital with angioedema from January 2012 to December 2014 was performed. Patient demographics and hospital course were gathered. Environmental data on the dates of presentation, including precipitation, humidity, and air pollution, were obtained from regional Environmental Protection Agency online data banks and used for statistical analysis.

RESULTS

In total, 408 patients, representing 450 episodes of angioedema, met the inclusion criteria for the study. Most patients were female (58%), African American (74%), and on an angiotensin-converting enzyme inhibitor (ACE-I) upon presentation (61%). Days with unhealthy levels of air pollution were associated with an increased likelihood of angioedema presentation (odds ratio [OR], 1.82; confidence interval [CI], 1.01-3.30; P = .046). Subgroup analysis revealed that elevated ground-level ozone was the primary air pollutant significantly associated with angioedema presentations (OR, 4.95; CI 1.92-12.76; P = .0009). Higher ground-level ozone was also associated with ACE-I angioedema presentations (P = .017) but not with non-ACE-I angioedema presentations (P = .86). Air quality was not predictive of angioedema severity or need for intubation.

CONCLUSION

Angioedema is a complex, multifactorial disease resulting in potentially life-threatening complications. This is the first study to demonstrate that higher levels of air pollution, specifically ground-level ozone, are associated with significantly increased rates of angioedema episodes, although not severity.