Hereditary angioedema attack: what happens to vasoactive mediators?

Hereditary angioedema is a disabling, life-threatening condition caused by deficiency (type I) or dysfunction (type II) of the C1 inhibitor protein (C1-INH-HAE) leading to bradykinin accumulation and recurrent episodes of edema attack. Vascular leakage is a complex process sustained by the coordinated production of several permeabilizing factors including vascular endothelial growth factors (VEGFs), angiopoietins (ANGPTs) and phospholipase A2 enzymes (PLA2). We previously reported that patients with C1-INH-HAE in remission have increased plasma levels of VEGFs, ANGPTs and secreted PLA2. In this study, we sought to analyze plasma levels of these mediators in 15 patients with C1-INH-HAE during the acute attack compared to remission. Plasma concentrations of VEGF-A, VEGF-C and VEGF-D were not altered during attack compared to remission. Moreover, VEGF-D concentrations were not altered also in remission phase compared to controls. Concentrations of ANGPT1, a vascular stabilizer, were increased during attacks compared to symptoms-free periods, whereas ANGPT2 levels were not altered. The ANGPT2/ANGPT1 ratio was decreased during angioedema attacks. Platelet activating factor acetylhydrolase activity was increased in patients with C1-INH-HAE in remission compared to controls and was decreased during angioedema attacks. Our results emphasize the complexity by which several vasoactive mediators are involved not only in the pathophysiology of C1-INH-HAE, but also during angioedema attacks and its resolution.

The Role of Complement in Hereditary Angioedema.

Low levels of C1 inhibitor, the main inhibitor of the classic complement system, result in paroxysmal angioedema attacks that can be incapacitating or even life-threatening in affected individuals. Molecular defects in the gene for C1 inhibitor cause hereditary angioedema. In recent years, new insights in the pathways leading to angioedema due to a deficiency of C1 inhibitor have been gathered. Bradykinin, which is formed upon activation of the kallikrein-kinin system under insufficient regulation by C1 inhibitor, plays a crucial role. Whereas C1 inhibitor also occupies a central mediatory role in other plasma systems, such as the contact activation system of coagulation and the fibrinolytic plasminogen-plasmin system, a C1 inhibitor deficiency may also cause enhanced activation of these pathways. Novel therapeutic modalities for treatment and prevention of hereditary angioedema are now available, such as different forms of C1 inhibitor concentrate and novel agents that interfere in the kallikrein-kinin system.

Management of pregnancy and delivery in patients with hereditary angioedema due to C1 inhibitor deficiency

Background and Objective: There is little information on pregnancy and delivery in patients with hereditary angioedema due to C1 inhibitor deficiency (C1INH-HAE). The aim of this study was to describe the effect of pregnancy and deliveries on symptoms of C1INH-HAE and review the need for and safety of treatments available during the study period. Methods: Retrospective review using a purpose-designed questionnaire of 61 C1INH-HAE patients from 5 hospitals specialized in the management of HAE in Spain. The outcomes measured were number of pregnancies, changes in symptoms during pregnancy and delivery, mode of delivery, type of anesthesia during delivery, treatments received, and tolerance of treatments. Results: We reviewed 125 full-term pregnancies (89 without a prior diagnosis of C1INH-HAE), 14 miscarriages, and 4 induced abortions. Patients reported an increased frequency of C1INH-HAE symptoms in 59.2% of pregnancies (74/125) and the presence of symptoms throughout pregnancy in 40% (50/125). Prophylactic C1INH-HAE therapy was used during 9 (7.2%) of the 125 pregnancies. Nine patients—in 11 pregnancies (8.8 %)—received treatment for acute attacks. Most deliveries (n=110, 88%) were vaginal. A cesarean section was necessary in 15 cases (12%). Short-term prophylaxis with pdhC1INH was administered before 14 deliveries (11.2 %); 111 deliveries (88.8 %) were performed without premedication and were well tolerated. Anesthesia was used in 51 deliveries (40.8%). Conclusions: Pregnancy has a variable influence on the clinical expression of C1INH-HAE. Attacks tend to occur more frequently but not to increase in severity. Vaginal delivery was mostly well tolerated. pdhC1INH prophylaxis should be administered prior to cesarean delivery and is also recommended before vaginal delivery if there are additional risk factors. pdhC1INH should always be available in the delivery room (AU)

Antecedentes y Objetivo: Existe escasa información sobre la evolución del embarazo y el parto en pacientes con angioedema hereditario con déficit de C1 Inhibidor (AEH-C1INH). El objetivo del estudio fue describir el efecto de embarazo y parto en los síntomas de AEH-C1INH y la necesidad y seguridad de las terapias disponibles durante dicho período. Diseño: Revisión retrospectiva de datos registrados en 5 centros hospitalarios españoles expertos en AEH. Pacientes y Métodos: 61 mujeres con diagnóstico de AEH-C1INH antes o después de su(s) embarazo(s). Se rellenó un cuestionario específico. Fue evaluado: número de embarazos, evolución de síntomas de AEH durante embarazo(s) y parto(s), tipo de parto, tipo de anestesia durante el parto, tratamientos recibidos y su tolerancia. Resultados: Se revisaron 125 embarazos a término (en 89 embarazos las pacientes estaban sin diagnosticar de AEH) y 18 abortos. Hubo aumento en la frecuencia de síntomas de AEH en 59,2% de embarazos (74/125) y los síntomas estuvieron presentes a lo largo de todos los trimestres en el 40% (50/125). Se usó tratamiento preventivo en 9 de los 125 embarazos (7,2%). Nueve pacientes -en 11 embarazos- (8,8%) recibieron tratamiento para crisis agudas. 110 partos (88%) fueron vaginales, mientras que 15 (12%) fueron cesáreas. Se usó tratamiento profiláctico con concentrado de C1-Inhibidor (pdhC1INH) antes de 14 partos (11,2%). Se completaron 111 partos (88,8%) sin ningún tipo de premedicación y resultaron bien tolerados. Se usó anestesia en 51 partos (41,6%). Conclusiones: La influencia del embarazo en la expresión clínica de la enfermedad es variable, no obstante las crisis tienden a aumentar en frecuencia pero no en gravedad. El parto vaginal fue habitualmente bien tolerado. El pdhC1INH debe administrarse antes de un parto mediante cesárea y también se recomendaría en caso de parto vaginal si existiera algún factor de riesgo adicional. El pdhC1INH debe estar siempre disponible en la sala de partos (AU)

Electroconvulsive therapy in patients with C1 inhibitor deficiency: a major or minor procedure?

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A unique case of angioedema with anti-C1 inhibitor antibodies and normal C1 inhibitor levels

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Angioedema hereditario en Medellín, Colombia: evaluación clínica y de la calidad de vida / Hereditary angioedema in Medellín (Colombia): Clinical evaluation and quality of life appraisal

Introducción. El angioedema hereditario es una inmunodeficiencia primaria de carácter autosómico dominante, debida a un déficit en la proteína inhibidora del factor C1 y caracterizada por episodios recurrentes de edema subcutáneo y de las mucosas. Las impredecibles y frecuentes crisis de angioedema afectan la calidad de vida de los individuos que las padecen. Objetivo. Analizar las características clínicas de una familia con un caso índice de angioedema hereditario y determinar el impacto de la enfermedad en la calidad de vida. Materiales y métodos. En el estudio se incluyeron 26 miembros de la familia, a 25 de los cuales se les midieron los niveles sanguíneos del factor C4 del complemento y del inhibidor de C1 antigénico y funcional. Se utilizaron dos instrumentos, el SF-36 para evaluar la salud del adulto y el KIDSCREEN-27 para la calidad de vida de niños y adolescentes. Resultados. El 83 % de los individuos que reportaron síntomas cumplían con los criterios serológicos del angioedema hereditario de tipo I: valores bajos del factor C4 del complemento y del inhibidor de C1 cuantitativo (antigénico) y cualitativo (funcional). Se encontró que la calidad de vida en cuanto al bienestar psicológico y el desempeño emocional de los pacientes, se veía considerablemente afectada por los síntomas de la enfermedad. Conclusión. Este estudio provee información sobre la primera familia caracterizada con angioedema hereditario de tipo 1 en el Valle de Aburrá, Colombia. Aunque para ello se usó un instrumento genérico, se confirmó, además, el efecto negativo de la enfermedad en la calidad de vida de los individuos que la padecen.

Introduction: Hereditary angioedema is an autosomal dominant primary immunodeficiency caused by a deficiency of the C1 inhibitor protein and characterized by recurrent episodes of subcutaneous and mucosal edema. Unpredictable and frequent crisis of angioedema affect the quality of life of individuals suffering this kind of disorder. Objective: To analyze the clinical characteristics of a family with an index case of hereditary angioedema and to determine the impact of this disease on their quality of life. Materials and methods: Twenty six members of the family were included in the trial; 25 of them were analyzed for C4 complement and antigenic and functional C1 inhibitor blood levels. Two instruments (SF-365 and KIDSCREEN-27) were used to evaluate adult health quality and children and teenagers quality of life, respectively. Results: Eighty three percent (83%) of individuals reporting symptoms of the condition exhibited serological criteria of hereditary angioedema type I: low levels of both C4 complement and quantitative (antigenic) and qualitative (functional) C1 inhibitor. In relation to patients' psychological and emotional performance, their quality of life was significantly affected by the symptoms of hereditary angioedema. Conclusion: This study provides evidence of the first family in Valle de Aburrá (Colombia) characterized as having hereditary angioedema type I. Despite the use of a generic instrument, the negative impact on the quality of life of individuals suffering this disease was also confirmed.

[Hereditary angioedema in Medellín (Colombia): Clinical evaluation and quality of life appraisal]. / Angioedema hereditario en Medellín, Colombia: evaluación clínica y de la calidad de vida.

INTRODUCTION: Hereditary angioedema is an autosomal dominant primary immunodeficiency caused by a deficiency of the C1 inhibitor protein and characterized by recurrent episodes of subcutaneous and mucosal edema. Unpredictable and frequent crisis of angioedema affect the quality of life of individuals suffering this kind of disorder. OBJECTIVE: To analyze the clinical characteristics of a family with an index case of hereditary angioedema and to determine the impact of this disease on their quality of life. MATERIALS AND METHODS: Twenty six members of the family were included in the trial; 25 of them were analyzed for C4 complement and antigenic and functional C1 inhibitor blood levels. Two instruments (SF-365 and KIDSCREEN-27) were used to evaluate adult health quality and children and teenagers quality of life, respectively. RESULTS: Eighty three percent (83%) of individuals reporting symptoms of the condition exhibited serological criteria of hereditary angioedema type I: low levels of both C4 complement and quantitative (antigenic) and qualitative (functional) C1 inhibitor. In relation to patients' psychological and emotional performance, their quality of life was significantly affected by the symptoms of hereditary angioedema. CONCLUSION: This study provides evidence of the first family in Valle de Aburrá (Colombia) characterized as having hereditary angioedema type I. Despite the use of a generic instrument, the negative impact on the quality of life of individuals suffering this disease was also confirmed.

Endothelial cell activation during edematous attacks of hereditary angioedema types I and II.

BACKGROUND: Hereditary angioedema (HAE) caused by C1-inhibitor (C1-INH) deficiency (HAE-C1-INH) is a potentially life-threatening rare disease caused by the decreased activity of C1-INH. Lack of C1-INH leads to overproduction of bradykinin, a potent vasoactive peptide. Although angioedema is induced by bradykinin, the function and activation of endothelial cells (ECs), the targets of bradykinin, have not yet been studied during HAE attacks. OBJECTIVE: We studied whether EC function is altered during HAE attacks in comparison with attack-free intervals. METHODS: Forty-six consecutive samples obtained during attacks from 18 patients with HAE-C1-INH were compared with inter-attack samples of the same patients. The patients' sera were tested for von Willebrand factor (VWF) antigen, VWF collagen-binding activity, soluble E-selectin, and endothelin-1 levels by using ELISA and BRAHMS Kryptor technologies. RESULTS: Levels of all 4 EC markers (VWF antigen, VWF collagen-binding activity, soluble E-selectin, and endothelin-1) were significantly increased during HAE attacks. Their increases were even more obvious in the subgroup of patients without any pre-existing risk factors for endothelial dysfunction. CONCLUSION: In this study we demonstrated that ECs are activated during HAE attacks. Our results might suggest the need for revising the knowledge on the pathogenesis of HAE-C1-INH and for reconsidering the role of ECs as a possible novel therapeutic target in patients with this disease.

Risk of angioedema following invasive or surgical procedures in HAE type I and II--the natural history.

BACKGROUND: Hereditary angioedema (HAE), caused by deficiency in C1-inhibitor (C1-INH), leads to unpredictable edema of subcutaneous tissues with potentially fatal complications. As surgery can be a trigger for edema episodes, current guidelines recommend preoperative prophylaxis with C1-INH or attenuated androgens in patients with HAE undergoing surgery. However, the risk of an HAE attack in patients without prophylaxis has not been quantified. OBJECTIVES: This analysis examined rates of perioperative edema in patients with HAE not receiving prophylaxis. METHODS: This was a retrospective analysis of records of randomly selected patients with HAE type I or II treated at the Frankfurt Comprehensive Care Centre. These were examined for information about surgical procedures and the presence of perioperative angioedema. RESULTS: A total of 331 patients were included; 247 underwent 700 invasive procedures. Of these procedures, 335 were conducted in 144 patients who had not received prophylaxis at the time of surgery. Categories representing significant numbers of procedures were abdominal (n = 113), ENT (n = 71), and gynecological (n = 58) procedures. The rate of documented angioedema without prophylaxis across all procedures was 5.7%; in 24.8% of procedures, the presence of perioperative angioedema could not be excluded, leading to a maximum potential risk of 30.5%. Predictors of perioperative angioedema could not be identified. CONCLUSION: The risk of perioperative angioedema in patients with HAE type I or II without prophylaxis undergoing surgical procedures ranged from 5.7% to 30.5% (CI 3.5-35.7%). The unpredictability of HAE episodes supports current international treatment recommendations to consider short-term prophylaxis for all HAE patients undergoing surgery.

Overview of hereditary angioedema caused by C1-inhibitor deficiency: assessment and clinical management.

Hereditary angioedema due to C1-inhibitor deficiency (HAE-C1-INH) is a rare, autosomal-dominant disease. HAE-C1-INH is characterized by recurrent attacks of marked, diffuse, nonpitting and nonpruritic skin swellings, painful abdominal attacks, and laryngeal edema. The extremities and the gastrointestinal tract are most commonly affected. Swelling of the upper respiratory mucosa poses the greatest risk because death from asphyxiation can result from laryngealedema. HAE-C1-INH attacks are variable, unpredictable, and may be induced by a variety of stimuli, including stress or physical trauma. Because the clinical presentation of HAE-C1-INH is similar to other types of angioedema, the condition may be a challenge to diagnose. Accurate identification of HAE-C1-INH is critical in order to avoid asphyxiation by laryngeal edema and to improve the burden of disease. Based on an understanding of the underlying pathophysiology of IHAE-C1-INH, drugs targeted specifically to the disease, such as C1-inhibitor therapy, bradykinin B2-receptor antagonists, and kallikrein-inhibitors, have become available for both treatment and prevention of angioedema attacks. This article reviews the clinical features, differential diagnosis, and current approaches to management of HAE-C1-INH.

Angio-oedema due to hereditary C1 inhibitor deficiency in children

Hereditary angio-oedema due to C1 inhibitor deficiency (HAE-C1-INH) is a rare inherited disorder characterised by recurring and debilitating episodes of cutaneous swelling and abdominal pain and less frequent episodes of laryngeal oedema. Symptom onset is usually in childhood and early adolescence, with earlier disease onset associated with greater disease severity. Although HAE-C1-INH attacks are generally less frequent and less severe in children than in adults, they can cause significant physical and psychological impairment and affect advancement in school. There are often significant delays in the diagnosis of HAE-C1-INH due to its variable clinical presentation and because abdominal symptoms can often mimic other common paediatric gastrointestinal disorders. In recent years, several disease-specific agents have become available for the acute and prophylactic treatment of HAE-C1-INH. Although these treatments have not been evaluated rigorously in controlled clinical trials in children with HAE-C1-INH, paediatric data on efficacy and safety are available for some agents. Early diagnosis and initiation of appropriate therapy in children with HAE-C1-INH can help reduce the burden of this illness in the paediatric population(AU)

A novel mutation in exon 8 of C1 inhibitor (C1INH) gene leads to abolish its physiological stop codon in a large Chinese family with hereditary angioedema type I.

C1 inhibitor (C1INH) plays an important role in the classical pathway of the complement system. Mutations in C1INH gene cause quantitative or qualitative deficiencies in C1INH, which can lead to hereditary angioedema (HAE) type I or II. Here, we identified a novel frame-shift mutation c.1391-1445del55 (p.v464fsx556) in exon 8 in a large Chinese family with HAE type I. This 55 base pairs deletion abolishes the original stop codon and introduces a new stop codon 220 bp downstream of the original one, and leads to mutated C1INH protein prolonged from 500 to 556 amino acids. The levels of C4 and C1INH as well as C1INH activity in serum were significantly reduced in affected individuals. This is the first report of a novel mutation abolishing the physiological stop codon of C1INH gene in a large Chinese family with HAE type I.

The autoreactivity of B cells in hereditary angioedema due to C1 inhibitor deficiency.

Patients with hereditary angioedema (HAE) tend to produce autoantibodies and have a propensity to develop immunoregulatory disorders. We characterize the profile of autoantibodies in a group of HAE patients and investigate their memory B cells' phenotype and activation status. We studied the activity status phenotype, Toll-like receptor (TLR)-9 expression and total phosphotyrosine in B cells isolated from HAE patients. Additionally, the following autoantibodies were assessed in the serum of 61 HAE patients: anti-nuclear, rheumatoid factor, anti-cardiolipin, anti-tissue transglutaminase, anti-endomysial, anti-Saccharomyces cerevisiae, anti-thyroid and anti-neutrophil cytoplasmic antibodies. In 47·5% of HAE patients we detected at least one of the tested autoantibodies. Expression of CD69, CD5 and CD21 was found to be significantly higher on memory B cells from HAE patients compared to healthy controls (4·59 ± 4·41 versus 2·06 ± 1·81, P = 0·04, 8·22 ± 7·17 versus 3·65 ± 3·78, P = 0·05, 2·43 ± 0·54 versus 1·92 ± 0·41, P = 0·01, respectively). Total phosphotyrosine in B cells from HAE patients was significantly higher compared to healthy controls (4·8 ± 1·1 versus 2·7 ± 1·3, P = 0·0003). Memory B cells isolated from the HAE group contained higher amounts of TLR-9 compared to healthy controls (8·17 ± 4·1 versus 4·56 ± 1·6, P = 0·0027). Furthermore, the expression of TLR-9 in memory B cells from HAE patients with autoantibodies was significantly higher than the control group (10 ± 4·7 versus 4·56 ± 1·6, P = 0·0002) and from that in HAE patients without autoantibodies (10 ± 4·7 versus 5·8 ± 0·9, P = 0·036). HAE patients have enhanced production of autoantibodies due most probably to the increased activation of B cells, which was found to be in association with a high expression of TLR-9.

Cross-talk between the complement and the kinin system in vascular permeability.

The endothelium is a continuous physical barrier that regulates coagulation and selective passage of soluble molecules and circulating cells through the vessel wall into the tissue. Due to its anatomic localization, the endothelium may establish contact with components of the complement, the kinin and the coagulation systems which are the main, though not exclusive, inducers of vascular leakage. Although the complement and the kinin systems may act independently, increasing evidence suggest that there is a crosstalk that involve different components of both systems. Activation is required for the function of the two systems which are involved in pathological conditions such as hereditary and acquired angioedema (AE) and vasculitidis. The aim of this review is to discuss the contribution of complement and kinin systems to vascular leakage and the cross-talk between the two systems in the development of AE. This clinical condition is characterized by episodic and recurrent local edema of subcutaneous and submucosal tissues and is due to inherited or acquired C1-INH deficiency. Although the pathogenesis of the swelling in patients with AE was originally thought to be mediated by C2, ample evidence indicate bradykinin (BK) as the most effective mediator even though the possibility that both the complement and the kinin-forming systems may contribute to the edema has not been completely excluded. BK induces endothelial leakage interacting with B2 receptors but other molecules may be involved in the onset and maintenance of AE. In this review we shall discuss the role of B1 receptors and gC1qR/p33 in addition to that of B2 receptors in the onset of AE attacks and the importance of these receptors as new possible molecular targets for therapy.

Lack of increased prevalence of immunoregulatory disorders in hereditary angioedema due to C1-inhibitor deficiency.

Hereditary angioedema due to deficiency of C1-INH (HAE-C1-INH) is associated with enhanced consumption of the early complement components, which may predispose for autoimmune disease. We assessed the prevalence of such disorders among HAE- C1-INH patients and their impact on the natural course of HAE-C1-INH. Clinical data and immunoserological parameters of 130 HAE-C1-INH and 174 non-C1-INH-deficient patients with angioedema were analyzed. In our study, the incidence of immunoregulatory disorders was 11.5% in the population of HAE-C1-INH patients and 5.2% among non-C1-INH-deficient controls with angioedema. Immunoserology screening revealed a greater prevalence of anticardiolipin IgM (p=0.0118) among HAE-C1-INH patients, than in those with non-C1-INH-deficient angioedema. We did not find higher prevalence of immunoregulatory disorders among our HAE-C1-INH patients. However, in patients with confirmed immunoregulatory disorders, the latter influenced both the severity of HAE-C1-INH and the effectiveness of its long-term management. Appropriate management of the immunoregulatory disease thus identified improves the symptoms of HAE-C1-INH.

Association of celiac disease and hereditary angioedema due to C1-inhibitor deficiency. Screening patients with hereditary angioedema for celiac disease: is it worth the effort?

OBJECTIVE: Hereditary angioedema due to C1-inhibitor deficiency is a life-threatening condition, which manifests as edematous attacks involving subcutaneous tissues and/or the upper airway/gastrointestinal mucosa. Celiac disease is a gluten-sensitive small intestinal disorder that can lead to severe villous atrophy, malabsorption, and malignancy. Both hereditary angioedema and celiac disease may present with abdominal symptoms. Our aim was to study the occurrence of celiac disease in the hereditary angioedema population, as well as to analyze the clinical course of cases with both diseases. METHODS: One hundred and twenty-eight patients with hereditary angioedema were screened for celiac disease, using serological methods [antiendomysial antibodies-immunoglobulin A (IgA), antiendomysial antibodies-IgG and tissue transglutaminase-IgA, tissue transglutaminase-IgG]. Clinical data of a child with hereditary angioedema and celiac disease diagnosed earlier were added to the dataset to be analyzed. Thus, the total number of patients was 129, comprising 107 adults and 22 pediatric patients. In patients with celiac disease, molecular genetics analysis (human leukocyte antigen-DQA1, human leukocyte antigen-DQB1) was carried out along with the introduction of a gluten-free diet and regular follow-up. RESULTS: Four out of the 22 children were diagnosed with celiac disease in our hereditary angioedema population. The prevalence of celiac disease among our pediatric patients with hereditary angioedema (22 children) was higher than in the general population (18.1 vs. 1.2%). Switching from the wheat starch-containing tranexamic acid product to danazol and introducing a gluten-free diet mitigated abdominal symptoms of hereditary angioedema. CONCLUSION: Similarities between the symptoms of hereditary angioedema and celiac disease may cause difficulties in differential diagnosis, as well as in choosing the appropriate therapy. In our opinion, screening hereditary angioedema patients for celiac disease is warranted if abdominal attacks or neurological symptoms persist despite adequate management. Complement testing is recommended whenever abdominal symptoms persist despite the histological and serological remission of gluten-sensitive enteropathy after the introduction of a gluten-free diet.