Icatibant treatment for acquired C1-inhibitor deficiency: a real-world observational study

Efficacy and Safety of Rituximab-Based Treatments in Angioedema With Acquired C1-Inhibitor Deficiency

BACKGROUND

Angioedema (AE) due to acquired C1-inhibitor (C1-INH) deficiency (AAE-C1-INH) is related to excessive consumption of C1-INH or to anti-C1-INH antibodies, and is frequently associated with lymphoproliferative syndromes or monoclonal gammopathies. Standard of care for prophylactic treatment in this condition is not established. Rituximab may be effective to prevent attacks, especially if the lymphoid hemopathy is controlled, but data are scarce.

OBJECTIVE

To evaluate efficacy of rituximab in AAE-C1-INH.

METHODS

A retrospective multicenter study was carried out in France, including patients with AAE-C1-INH treated with rituximab between April 2005 and July 2019.

RESULTS

Fifty-five patients with AAE-C1-INH were included in the study, and 23 of them had an anti-C1-INH antibody. A lymphoid malignancy was identified in 39 patients, and a monoclonal gammopathy in 9. There was no associated condition in 7 cases. Thirty patients received rituximab alone or in association with chemotherapy (n = 25). Among 51 patients with available follow-up, 34 patients were in clinical remission and 17 patients had active AE after a median follow-up of 3.9 years (interquartile range, 1.5-7.7). Three patients died. The presence of anti-C1-INH antibodies was associated with a lower probability of AE remission (hazard ratio, 0.29 [95% CI, 0.12-0.67]; P = .004). Relapse was less frequent in patients with lymphoma (risk ratio, 0.27 [95% CI, 0.09-0.80]; P = .019) and in patients treated with rituximab and chemotherapy (risk ratio, 0.31 [95% CI, 0.12-0.79]; P = .014).

CONCLUSIONS

Rituximab is an efficient and well-tolerated therapeutic option in AE, especially in lymphoid malignancies and in the absence of detectable anti-C1-INH antibodies.

Acquired Angioedema Due to C1-Inhibitor Deficiency (AAE-C1-INH)-A Bicenter Retrospective Study on Diagnosis, Course, and Therapy

BACKGROUND

Acquired angioedema with C1-inhibitor deficiency (AAE-C1-INH) is a rare condition resembling hereditary angioedema (HAE), but with late onset and low C1-inhibitor (C1-INH) due to consumption potentially caused by autoimmune diseases and mainly lymphatic malignancies. Being about 10-fold rarer than HAE, there is limited knowledge and no licensed therapy.

OBJECTIVE

To report clinical and biological data from a newly described population of 20 patients with AAE-C1-INH assessing diagnostic delay, AAE-C1-INH:HAE-ratio, underlying conditions, and therapeutic management in Germany.

METHODS

Retrospective data analysis of 20 patients from 2 angioedema centers in southern Germany.

RESULTS

Median age at symptoms' onset was 64 years (60% females), with predominant swellings of the face (85%) and low levels for C1-INH in almost all patients. The ratio AAE-C1-INH:HAE was 1:9.7. From symptoms' onset to diagnosis of AAE-C1-INH, the median delay was 7.5 months, and between AAE-C1-INH symptoms' onset and diagnosis of the underlying hematological condition (n = 9) it was 4 months (median). Four patients had a history of solid neoplasm, 1 had a papillary thyroid carcinoma as the only potential cause for AAE-C1-INH, with treatment of the malignancy resulting in resolution of AAE-C1-INH. All the symptomatic patients were treated with off-label on-demand icatibant subcutaneously or C1-INH concentrate intravenously, and 6 severely affected patients needed off-label long-term prophylaxis with good symptom control.

CONCLUSIONS

AAE-C1-INH is characterized by late-onset swellings mainly involving the face and low C1-INH levels. Diagnostic delay for AAE-C1-INH is further decreasing despite being about 10-fold rarer than HAE. Patients severely affected without underlying condition or no indication for treatment could benefit from off-label therapy.

A Retrospective Analysis of Long-Term Prophylaxis with Berotralstat in Patients with Hereditary Angioedema and Acquired C1-Inhibitor Deficiency-Real-World Data

Hereditary angioedema (HAE) and acquired C1-inhibitor deficiency (AAE-C1-INH) are orphan diseases. Berotralstat is a recently licensed long-term prophylaxis (LTP) and the first oral therapy for HAE patients. No approved therapies exist for AAE-C1-INH patients. This study is the first to report real-world clinical data of patients with AAE-C1-INH and HAE who received Berotralstat. All patients treated with Berotralstat were included in this retrospective, bi-centric study. Data was collected from patients' attack calendars and the angioedema quality of life (AE-QoL) and angioedema control test (AECT) questionnaires before treatment, and at 3, 6, and 12 months after treatment and was then analyzed. Twelve patients were included, 3 patients with AAE-C1-INH, 7 patients with HAE type I, and 2 patients with HAE-nC1-INH. One patient (HAE I) quit treatment. Berotralstat was associated with fewer attacks in all groups. After 6 months of treatment, a median decrease of attacks per month was noted for HAE type I patients (3.3 to 1.5) and AAE-C1-INH patients (2.3 to 1.0). No aerodigestive attacks were noted for AAE-C1-INH patients. For HAE-nC1-INH patients, a mean decrease from 3.8 to 1.0 was noted (3 months). For HAE I patients, the total AE-QoL lowered a mean of 24.1 points after 6 months, for HAE-nC1-HAE patients 8.0 points, and for AAE-C1-INH patients 13.7 points. AECT scores increased for HAE I patients (mean: 7.1), HAE-nC1-INH patients (9.0), and AAE-C1-INH patients (4.2) after 6 months. Patients with HAE, HAE-nC1-INH, and AAE-C1-INH treated with Berotralstat showed reduced angioedema attacks and improved AE-QoL and AECT scores.

Where we are with acquired angioedema due to C1 inhibitor deficiency: A systematic literature review

Acquired angioedema due to C1 inhibitor deficiency (C1-INH-AAE) is a rare disease characterized by adult-onset recurrent non-urticarial angioedema with low levels of C1-INH. It is associated with lymphoproliferative disorders, and treatments are off-label with variable success. We conducted a systematic literature review to include patients with C1-INH-AAE identified in PubMed and Embase databases between January 2006 and February 2021. Clinical features of these patients were summarized, and factors associated with disease remission were explored. A total of 121 patients were included in the current study with a median age at diagnosis of 64 years and 45.5% being male. An associated disease was recorded in 94 patients (77.7%), and lymphoproliferative disorder was the most reported (59/94, 62.8%). Anti-C1-INH autoantibodies were present in 45 of 71 patients (63.4%). Factors impacting disease remissions included age (odds ratio [OR] 0.951, 95% confidence interval [CI] 0.909-0.994, p = 0.027), male (OR 0.327, 95% CI 0.124-0.866, p = 0.025), presence of monoclonal gammopathy (OR 0.133, 95% CI 0.041-0.429, p = 0.001), requirement of specific on-demand treatment (OR 0.216, 95% CI 0.066-0.709, p = 0.012) and rituximab use (OR 2.865, 95% CI 1.038-7.911, p = 0.042). A total of nine patients (7.4%) died at last follow up and most were unrelated to C1-INH-AAE. Our results imply that C1-INH-AAE is primarily associated with underlying B or plasma cell abnormalities, and clone-directed therapies could be promising options for its long-term management.

Angioedema with severe acute abdominal pain: Think of hereditary angioedema

Angioedema can be either mast cell-(histamine-)mediated or bradykinin-mediated. Treatment approaches for the two types are very different, making differential diagnosis critical. Severe acute abdominal pain caused by intestinal angioedema is commonly misdiagnosed, especially when associated with bradykinin-mediated angioedema. After describing a typical clinical scenario and diagnostic journey of a patient with recurrent, undiagnosed abdominal pain due to hereditary angioedema (HAE), a rare variant of bradykinin-mediated angioedema, we delve into the classification and differential diagnosis of the various types of angioedema and provide an overview of appropriate management with an emphasis on the bradykinin-mediated types. Bradykinin-induced angioedema may be inherited or acquired and is infrequent compared to mast cell-mediated angioedema. HAE is a rare disease characterized by recurrent attacks of non-urticarial, nonpruritic edema usually affecting the face, respiratory tract, extremities, gastrointestinal tract, and genitalia. Unlike mast cell-mediated angioedema, painful abdominal symptoms are prevalent in bradykinin-mediated angioedema and are sometimes the only manifestation of an attack, increasing the likelihood of initial misdiagnosis as appendicitis or other forms of acute abdomen. It is important for gastroenterologists to be vigilant for the possibility of angioedema pathology in patients presenting with undiagnosed, recurrent, abdominal symptoms to facilitate accurate diagnosis and effective treatment.

A follow-up survey of patients with acquired angioedema due to C1-inhibitor deficiency

BACKGROUND

Acquired angioedema due to C1-inhibitor deficiency (C1-INH-AAE) is a rare form of bradykinin-mediated angioedema. It is diagnosed by complement testing; its treatment consists of the management of angioedema (AE) attacks and of underlying disease.

OBJECTIVE

Evaluate the results of the clinical follow-up of patients with C1-INH-AAE.

METHODS

Between 1999 and 2020, 3938 patients with angioedema were evaluated, and 17 diagnosed with acquired C1-INH deficiency were followed-up.

RESULTS

Mean age of the 17 patients was 61 years at diagnosis. In 33%, ACE inhibitors provoked AE attacks. Autoantibodies against C1-INH were detected in 10 patients at diagnosis and in a further patient during follow-up. The AE attacks involved the skin in 70.6%, the upper airways in 41.2% and the tongue/lip in 52.9% of patients. Twelve of the 17 patients had an underlying condition, mainly (n = 11) lymphoproliferative disease. In 10 patients diagnosed with a haematological disorder, AAE symptoms preceded the onset of the latter. One patient has not experienced an AE attack since diagnosis. Twelve patients were treated for angioedema attacks, and 32% of the attacks required acute treatment. PdC1-INH was used to relieve AE attacks, and rituximab for the treatment of underlying disease (in six patients). Six patients had multiple AE attacks before any treatment. The symptom-free period increased in five patients after the on-demand administration of pdC1-INH concentrate and following treatment of the underlying disease in two patients.

CONCLUSION

Early diagnosis of C1-INH-AAE and underlying disease is indispensable to reduce disease burden by introducing appropriate, individualized treatment and regular follow-up.

The rash that presents as a red swollen face

A red swollen face can be a skin sign of a potentially life-threatening condition. We present in detail the main clinical presentations, diagnostic tests, and management of some of the most severe conditions that can frequently present as a red and swollen face: acute or recurrent angioedema, mast cell-driven or bradykinin-mediated angioedema, nonhereditary and hereditary angioedema, allergic or photoallergic facial contact dermatitis, contact urticaria, severe adverse drug reactions (particularly drug reaction with eosinophilia and systemic symptoms [DRESS]), skin infections (erysipelas, cellulitis, necrotizing fasciitis), and autoimmune diseases (dermatomyositis). There are many other conditions that also have to be considered in the differential diagnosis of a red swollen face.

An updated review on phenocopies of primary immunodeficiency diseases

Primary immunodeficiency diseases (PIDs) refer to a heterogenous group of disorders characterized clinically by increased susceptibility to infections, autoimmunity and increased risk of malignancies.

These group of disorders present with clinical manifestations similar to PIDs with known genetic defects but have either no genetic defect or have a somatic mutation and thus have been labelled as “Phenocopies of PIDs”. These diseases have been further subdivided into those associated with somatic mutations and those associated with presence of auto-antibodies against various cytokines.

In this review, we provide an update on clinical manifestations, diagnosis and management of these diseases.

Acquired complement C1 esterase inhibitor deficiency in a patient with a rare SERPING1 variant with unknown significance

Angioedema (AE) is caused by a wide range of diseases and pharmaceuticals; it can become life-threatening when located to the airways. Patients with deficiency or malfunction of complement C1 esterase inhibitor (hereditary or acquired) experience recurrent AE due to an accumulation of the vasoactive mediator bradykinin (BK). Complement C1 inhibitor normally decreases BK production, so a reduced function hereof causes increased levels. The diagnosis of hereditary or acquired AE can be difficult due to similarities to allergic reactions (swelling, abdominal pain, rash). We describe a 35-year-old man presenting with upper-airway AE progressing rapidly and promptly required cricothyroidotomy. Complement and autoantibody screening together with sequencing of SERPING1 were performed and gave the diagnosis of acquired complement C1 esterase inhibitor deficiency. The patient is unusual to have this disease before the age of 40 years. No associated comorbidities were found. It is important to know that antiallergic medication is not effective in BK-mediated AE.

Acquired C1 Inhibitor Deficiency

Acquired angioedema due to C1-INH deficiency (C1-INH-AAE) can occur when there are acquired (not inherited) deficiencies of C1-INH. A quantitative or functional C1-INH deficiency with negative family history and low C1q is diagnostic of C1-INH-AAE. The most common conditions associated with C1-INH-AAE are autoimmunity and B-cell lymphoproliferative disorders. A diagnosis of C1-INH-AAE can precede a diagnosis of lymphoproliferative disease and confers an increased risk for developing non-Hodgkin lymphoma. Treatment focuses on symptom control with therapies that regulate bradykinin activity (C1-INH concentrate, icatibant, ecallantide, tranexamic acid, androgens) and treatment of any underlying conditions.

Comparing acquired angioedema with hereditary angioedema (types I/II): findings from the Icatibant Outcome Survey

Icatibant is used to treat acute hereditary angioedema with C1 inhibitor deficiency types I/II (C1-INH-HAE types I/II) and has shown promise in angioedema due to acquired C1 inhibitor deficiency (C1-INH-AAE). Data from the Icatibant Outcome Survey (IOS) were analysed to evaluate the effectiveness of icatibant in the treatment of patients with C1-INH-AAE and compare disease characteristics with those with C1-INH-HAE types I/II. Key medical history (including prior occurrence of attacks) was recorded upon IOS enrolment. Thereafter, data were recorded retrospectively at approximately 6-month intervals during patient follow-up visits. In the icatibant-treated population, 16 patients with C1-INH-AAE had 287 attacks and 415 patients with C1-INH-HAE types I/II had 2245 attacks. Patients with C1-INH-AAE versus C1-INH-HAE types I/II were more often male (69 versus 42%; P = 0·035) and had a significantly later mean (95% confidence interval) age of symptom onset [57·9 (51·33-64·53) versus 14·0 (12·70-15·26) years]. Time from symptom onset to diagnosis was significantly shorter in patients with C1-INH-AAE versus C1-INH-HAE types I/II (mean 12·3 months versus 118·1 months; P = 0·006). Patients with C1-INH-AAE showed a trend for higher occurrence of attacks involving the face (35 versus 21% of attacks; P = 0·064). Overall, angioedema attacks were more severe in patients with C1-INH-HAE types I/II versus C1-INH-AAE (61 versus 40% of attacks were classified as severe to very severe; P < 0·001). Median total attack duration was 5·0 h and 9·0 h for patients with C1-INH-AAE versus C1-INH-HAE types I/II, respectively.

A nationwide study of acquired C1-inhibitor deficiency in France: Characteristics and treatment responses in 92 patients

Acquired angioedema (AAE) due to C1-inhibitor (C1INH) deficiency is rare. Treatment options for acute attacks are variable and used off-label. Successful treatment of the associated lymphoma with rituximab seems to prevent acute attacks in subjects with AAE. The aim of this study was to describe AAE manifestations, its associated diseases, and patients' responses to treatments in a representative cohort.A retrospective nationwide study was conducted in France. The inclusion criteria were recurrent angioedema attacks and an acquired decrease in functional C1INH <50% of the reference value.A total of 92 cases were included, with a median age at onset of 62 years. Facial edema and abdominal pain were the most frequent symptoms. Fifteen patients were hospitalized in the intensive care unit because of laryngeal edema, and 1 patient died. Anti-C1INH antibodies were present in 43 patients. The associated diseases were primarily non-Hodgkin lymphoma (n = 44, with 24 splenic marginal zone lymphomas) and monoclonal gammopathy of undetermined significance (n = 24). Three patients had myeloma, 1 had amyloid light-chain (of immunoglobulin) (AL) amyloidosis, 1 patient had a bronchial adenocarcinoma, and 19 patients had no associated disease. Icatibant relieved the symptoms in all treated patients (n = 26), and plasma-derived C1INH concentrate in 19 of 21 treated patients. Six patients experienced thromboembolic events under tranexamic acid prophylaxis. Rituximab prevented angioedema in 27 of 34 patients as a monotherapy or in association with chemotherapy. Splenectomy controlled AAE in 7 patients treated for splenic marginal zone lymphoma. After a median follow-up of 4.2 years, angioedema was on remission in 52 patients.AAE cases are primarily associated with indolent lymphoma-especially splenic marginal zone lymphoma-and monoclonal gammopathy of undetermined significance but not with autoimmune diseases or other conditions. Icatibant and plasma-derived C1INH concentrate control attacks; splenectomy and immunochemotherapy prevent angioedema in lymphoma setting.

Diagnostic and therapeutic management of hereditary angioedema due to C1-inhibitor deficiency: the Italian experience

PURPOSE OF REVIEW

Hereditary angioedema (HAE) due to C1-inhibitor (C1-INH) deficiency (C1-INH-HAE) is a rare disease, with a reported prevalence of about 1 : 50 000. C1-INH-HAE causes disabling symptoms, which may be life-threatening if swelling affects upper airways. Diagnostic procedures are now well established and the role of bradykinin as the main mediator of plasma outflow eliciting angioedema formation has been clearly elucidated.

RECENT FINDINGS

Increased understanding of the pathogenesis of C1-INH-HAE allowed in recent years the development of new drugs targeted to inhibit bradykinin synthesis (Ecallantide) or activity (Icatibant). At the same time, a recombinant C1-INH concentrate (Ruconest) was produced from the milk of transgenic rabbits and two plasma-derived C1-INHs (Berinert, Cinryze) underwent controlled trials to obtain marketing authorization. In 2012, an Italian network for C1-INH-HAE (ITACA) was established by physicians of 17 HAE reference centres to collect data from Italian patients and to homogenize and improve the diagnostic and therapeutic approach to the disease.

SUMMARY

Although there is a widespread agreement on therapeutic goals and treatment of C1-INH-HAE acute attacks, different approaches to prophylaxis are still present among HAE experts. The clinical experience of ITACA on a large population of C1-INH-HAE patients followed for several years may help in identifying the most effective strategies for the management of the disease.

Overview of Laboratory Testing and Clinical Presentations of Complement Deficiencies and Dysregulation

Historically, complement disorders have been attributed to immunodeficiency associated with severe or frequent infection. More recently, however, complement has been recognized for its role in inflammation, autoimmune disorders, and vision loss. This paradigm shift requires a fundamental change in how complement testing is performed and interpreted. Here, we provide an overview of the complement pathways and summarize recent literature related to hereditary and acquired angioedema, infectious diseases, autoimmunity, and age-related macular degeneration. The impact of complement dysregulation in atypical hemolytic uremic syndrome, paroxysmal nocturnal hemoglobinuria, and C3 glomerulopathies is also described. The advent of therapeutics such as eculizumab and other complement inhibitors has driven the need to more fully understand complement to facilitate diagnosis and monitoring. In this report, we review analytical methods and discuss challenges for the clinical laboratory in measuring this complex biochemical system.

C1 inhibitor deficiency: 2014 United Kingdom consensus document

C1 inhibitor deficiency is a rare disorder manifesting with recurrent attacks of disabling and potentially life-threatening angioedema. Here we present an updated 2014 United Kingdom consensus document for the management of C1 inhibitor-deficient patients, representing a joint venture between the United Kingdom Primary Immunodeficiency Network and Hereditary Angioedema UK. To develop the consensus, we assembled a multi-disciplinary steering group of clinicians, nurses and a patient representative. This steering group first met in 2012, developing a total of 48 recommendations across 11 themes. The statements were distributed to relevant clinicians and a representative group of patients to be scored for agreement on a Likert scale. All 48 statements achieved a high degree of consensus, indicating strong alignment of opinion. The recommendations have evolved significantly since the 2005 document, with particularly notable developments including an improved evidence base to guide dosing and indications for acute treatment, greater emphasis on home therapy for acute attacks and a strong focus on service organization.

Treatment of ACEI-related angioedema with icatibant: a case series

No specific drugs are licensed for the treatment of ACE inhibitor (ACEI)-acquired angioedema (ACEI-AAE). Icatibant, an antagonist of the B2 receptor of bradykinin, is a potential treatment for this condition; however, its use in this setting is poorly documented. We report here clinical outcomes of 13 patients with ACEI-AAE treated with icatibant, in a real-life setting. Thirteen patients on ACEI seen in an Emergency Department (ED) with angioedema involving face, lips or the upper airways were analyzed. Angioedema due to known causes other than ACEI treatment was excluded. Initially, all patients received standard therapy (antihistamine, corticosteroids and epinephrine). Due to the lack of response and a worsening severity of symptoms, all patients received one subcutaneous injection of icatibant (30 mg/mL). Following icatibant treatment, all patients experienced improvement in the symptoms. The median time from onset of clinical symptoms to injection of icatibant was 3 h (IQR 2.5-5.5 h). Symptom relief was reported at 30 min (IQR 27.5-70 min). A complete resolution of symptoms was observed at 5 h (IQR 4-7 h). Ten patients had previously experienced angioedema attacks. The Median time to complete resolution of the previous attacks was higher (54 h; IQR 33-63 h), than after icatibant (p = 0.002) therapy. No patients required tracheal intubation or tracheotomy, and all patients were discharged within 24 h. No adverse events were reported. Before discharge, all patients were instructed to discontinue ACEI, and to take a different antihypertensive agent. This case series supports the efficacy of icatibant in improving symptoms of ACEI-AAE.

An evidence based therapeutic approach to hereditary and acquired angioedema

PURPOSE OF REVIEW

Hereditary angioedema (HAE) due to C1 esterase inhibitor (C1-INH) deficiency (HAE-C1-INH), HAE with normal C1-INH, and acquired angioedema due to C1-INH deficiency are rare but important diseases that can be associated with significant morbidity and mortality. Research into the pathogenesis of angioedema has expanded greatly and has led to new clinical trials with novel therapeutic agents and strategies.

RECENT FINDINGS

Strategies for managing HAE-C1-INH are aimed at treating acute attacks or preventing attacks through the use of prophylactic treatment. Agents available in Europe for treating acute attacks include plasma-derived C1-INH concentrates, a bradykinin B2 receptor (B2R) antagonist, and a recombinant human C1-INH. In the USA, a plasma-derived C1-INH concentrate, a bradykinin B2R antagonist, and a plasma kallikrein inhibitor have been approved for the treatment of acute HAE-C1-INH attacks. C1-INH concentrates and attenuated androgens are used for short-term prophylactic treatment. Long-term prophylactic treatments include attenuated androgens, a plasma-derived C1-INH concentrate, and antifibrinolytics. Plasma-derived C1-INH and a bradykinin B2R antagonist are approved for self-administration at home.

SUMMARY

The number of management options for HAE-C1-INH and similar conditions has increased considerably within the last few years, thus helping to alleviate the burden of these rare diseases.

Lesson of the month 2: The limitations of steroid therapy in bradykinin-mediated angioedema attacks

Acute angioedema attacks are conventionally treated with antihistamines and steroids, in line with a presumed mechanism of disease involving overwhelming mast-cell degranulation. This approach overlooks a small but important minority of cases in which attacks are bradykinin driven and exhibit poor responsiveness to steroid or anti-histamine therapy. These patients may have a family history of angioedema (hereditary angioedema), or a past medical history including B-cell lymphoproliferative disorders or autoimmune disease (acquired angioedema). Rather than steroid therapy, they respond to administration of a bradykinin inhibitor, or more commonly, a C1 esterase inhibitor substitute, to control acute symptoms and reduce the probability of invasive airway insertion. In the long-term, they require C1 esterase inhibitor sparing therapy and a treat-the-cause approach to reduce the risk of recurrent attacks. We present here a case of a middle-aged woman who presented with recurrent angioedema of initially uncertain aetiology.

[Acquired angioedema]

Acquired angioedema are rare. They are associated with monoclonal gammapathies of uncertain significance (MGUS) or lymphomas. They give the same symptoms as the hereditary form and the same laryngeal risk. They are characterized by a low level of C4, C1Inh and C1q. They are linked to the consumption of C1Inh by the lymphoid cells or to the presence of anti-C1Inh autoantibodies. They must be treated by symptomatic treatment when attack occur (C1Inh concentrate and icatibant). The use of rituximab needs to prove its efficiency.

Update on skin allergy

Skin diseases with an allergic background such as atopic dermatitis, allergic contact dermatitis, and urticaria are very common. Moreover, diseases arising from a dysfunction of immune cells and/or their products often manifest with skin symptoms. This review aims to summarize recently published articles in order to highlight novel research findings, clinical trial results, and current guidelines on disease management. In recent years, an immense progress has been made in understanding the link between skin barrier dysfunction and allergic sensitization initiating the atopic march. In consequence, new strategies for treatment and prevention have been developed. Novel pathogenic insights, for example, into urticaria, angioedema, mastocytosis, led to the development of new therapeutic approaches and their implementation in daily patient care. By understanding distinct pathomechanisms, for example, the role of IL-1, novel entities such as autoinflammatory diseases have been described. Considerable effort has been made to improve and harmonize patient management as documented in several guidelines and position papers.

Classification, diagnosis, and approach to treatment for angioedema: consensus report from the Hereditary Angioedema International Working Group

Angioedema is defined as localized and self-limiting edema of the subcutaneous and submucosal tissue, due to a temporary increase in vascular permeability caused by the release of vasoactive mediator(s). When angioedema recurs without significant wheals, the patient should be diagnosed to have angioedema as a distinct disease. In the absence of accepted classification, different types of angioedema are not uniquely identified. For this reason, the European Academy of Allergy and Clinical Immunology gave its patronage to a consensus conference aimed at classifying angioedema. Four types of acquired and three types of hereditary angioedema were identified as separate forms from the analysis of the literature and were presented in detail at the meeting. Here, we summarize the analysis of the data and the resulting classification of angioedema.

Guidance for diagnosis and treatment of acute angioedema in the emergency department: consensus statement by a panel of Italian experts

Angioedema attacks, characterized by the transient swelling of the skin and mucosae, are a frequent cause of visits to the emergency department. Swellings of the oral cavity, tongue, or larynx can result in life-threatening airway obstruction, while abdominal attacks can cause severe pain and often lead to unnecessary surgery. The underlying pathophysiologic process resulting in increased vascular permeability and plasma extravasation is mediated by vasoactive molecules, most commonly histamine and bradykinin. Based on the mediator involved, distinct angioedema forms can be recognized, calling for distinct therapeutic approaches. Prompt recognition is challenging for the emergency physician. The low awareness among physicians of the existence of rare forms of angioedema with different aetiologies and pathogenesis, considerably adds to the problem. Also poorly appreciated by emergency personnel may be the recently introduced bradykinin-targeted treatments. The main objective of this consensus statement is to provide guidance for the management of acute angioedema in the emergency department, from presentation to discharge or hospital admission, with a focus on identifying patients in whom new treatments may prevent invasive intervention.

Diagnosis and Treatment of Bradykinin-Mediated Angioedema: Outcomes from an Angioedema Expert Consensus Meeting

Several types of angioedema exist beyond hereditary angioedema (HAE) types I/II; however, the diagnostic and treatment needs of these conditions are not well understood. Noticeably, there are no licensed treatments available for other forms of angioedema beyond HAE types I/II, and similarly they are unresponsive to conventional antihistamine/glucocorticoid treatment. A group of angioedema experts met in Budapest in May 2013 to discuss such issues, presenting their experience, reviewing available literature and identifying unmet diagnostic and treatment needs in three different angioedema types: HAE with normal C1-inhibitor (C1-INH; previously referred to as type III HAE); nonallergic angiotensin-converting enzyme inhibitor (ACEI)-induced angioedema (ACEI-AAE), and acquired angioedema due to C1-INH deficiency (C1-INH-AAE). The group identified unmet diagnostic and treatment needs in HAE-nC1-INH, C1-INH-AAE and ACEI-AAE, explored remedies and made recommendations on how to diagnose and treat these forms of angioedema. The group discussed the difficulties associated with using diagnostic markers, such as the level and function of C1-INH, C1q and C4 to reliably diagnose the angioedema type, and considered the use of genetic testing to identify mutations in <i>FXII</i> or <i>XPNPEP2 </i>that have been associated with HAE-nC1-INH and ACEI-AAE, respectively. Due to the lack of approved treatments for HAE-nC1-INH, ACEI-AAE and C1-INH-AAE, the group presented several case studies in which therapies approved for treatment of HAE types I/II, such as icatibant, ecallantide and pasteurized, nanofiltered C1-INH, were successful. It was uniformly agreed that further studies are needed to improve the diagnosis and treatment of angioedema other than HAE types I/II. i 2014 S. Karger AG, Basel

Acquired angioedema--occurrence, clinical features and associated disorders in a Danish nationwide patient cohort

BACKGROUND

The prevalence of acquired angioedema (AAE) is hitherto unknown and, to date, less than 200 patients have been reported worldwide. AAE is associated with lymphoproliferative conditions and autoantibodies against C1 inhibitor (C1INH). Rituximab (RTX) is increasingly used in the treatment of AAE patients.

METHODS

A nationwide study of AAE patients was performed in Denmark. Clinical features, associated disorders, treatments and outcomes were registered.

RESULTS

Eight AAE patients were identified. The diagnostic delay was on average 1 year and 8 months. Patients were treated with C1INH concentrate or icatibant on demand. Six patients were diagnosed with a clonal B-cell disorder during follow-up, on average 2.5 years after the first swelling. Two patients had monoclonal B-cell lymphocytosis (MBL). Two patients received RTX.

CONCLUSIONS

AAE is a rare condition occurring in less than 10% of patients with C1INH deficiency in Denmark. AAE is highly associated with haematologic disorders, and we recommend yearly follow-up visits with clinical examination and blood tests including flow cytometry to diagnose B-cell conditions at an early stage. We report 2 patients with AAE and associated MBL, which is a benign expansion of clonal B lymphocytes. MBL can be the precursor of chronic lymphocytic leukaemia or is associated with non-Hodgkin's lymphoma. If angioedema is poorly controlled with standard treatment regimens, we suggest treatment of the associated haematologic disorder. Based on a review of the literature and our own data, we recommend therapy with RTX, especially in patients with anti-C1INH autoantibodies.

Acquired C1-inhibitor deficiency and lymphoproliferative disorders: a tight relationship

Angioedema due to the acquired deficiency of C1-inhibitor is a rare disease known as acquired angioedema (AAE), which was first described in a patient with high-grade lymphoma and is frequently associated with lymphoproliferative diseases, including expansion of B cell clones producing anti-C1-INH autoantibodies, monoclonal gammopathy of uncertain significance (MGUS) and non-Hodgkin lymphoma (NHL). AAE is clinically similar to hereditary angioedema (HAE), and is characterized by recurrent episodes of sub-cutaneous and sub-mucosal edema. It may affect the face, tongue, extremities, trunk and genitals. The involvement of the gastrointestinal tract causes bowel sub-occlusion with severe pain, vomiting and diarrhea, whereas laryngeal edema can be life-threatening. Unlike those with HAE, AAE patients usually have late-onset symptoms, do not have a family history of angioedema and present variable response to treatment due to the hyper-catabolism of C1-inhibitor. Reduced C1-inhibitor function leads to activation of the classic complement pathway with its consumption and activation of the contact system leading to the generation of the vasoactive peptide bradykinin, which increases vascular permeability and induces angioedema. Lymphoprolipherative diseases and AAE are tightly linked with either angioedema or limphoprolyferation being the first symptom. Experimental data indicate that neoplastic tissue and/or anti-C1-inhibitor antibodies induce C1-inhibitor consumption, and this is further supported by the observation that cytotoxic treatment of the lymphoproliferative diseases associated with AAE variably reverses the complement impairment and leads to a clinical improvement in angioedema symptoms.

A patient with chronic lymphocytic leukemia and acquired angioedema: correlation of clinical and biochemical response to CLL therapy

Acquired angioedema (AAE) is a result of an acquired deficiency or inactivity of the C1 esterase inhibitor (C1-INH). There is a well-known link between AAE and lymphoplasmacytic disorders.A 65-year-old woman who was diagnosed with chronic lymphocytic leukemia (CLL), presented with recurrent episodes of angioedema. Although no association between the CLL and angioedema was initially recognized, further workup showed her to have low C1-INH levels. Chemotherapy helped prevent subsequent episodes, but three years later she redeveloped angioedema. She was then placed on ofatumumab maintenance and has since remained free of angioedema.Knowledge of this rare disease and anticipation of the link between CLL and AAE can prevent further attacks and associated morbidity.

Development and construct validation of the angioedema quality of life questionnaire

BACKGROUND

Recurrent angioedema is a frequent clinical problem characterized by unpredictably and rapidly occurring cutaneous and mucosal swellings. These swellings may be painful and/or disfiguring. Upper airway involvement can also lead to dyspnea and suffocation. Although the disease burden is high, there is currently no specific instrument to measure health-related quality of life (QoL) impairment.

OBJECTIVE

To develop and validate the first symptom-specific tool to assess QoL impairment in recurrent angioedema patients, adhering to established methodological recommendations.

METHODS

During the development phase, 29 questions (items) were generated. Subsequently, item reduction was performed by means of impact analysis and factor analysis as well as by checking for content and face validity. As a result, 17 items were selected and included in the final instrument, the Angioedema QoL Questionnaire (AE-QoL). AE-QoL was then tested for its validity, reliability, and influence factors.

RESULTS

One hundred and ten angioedema patients took part in the validation of AE-QoL. AE-QoL was found to have a four-dimensional structure as well as a valid total score. All of its four domains (functioning, fatigue/mood, fears/shame, food) showed good levels of internal consistency with Cronbach's alpha > 0.8. Test-retesting revealed a good reliability of the instruments total score and domain scores. Gender as well as the patients' self-rated disease activity was found to be predictors of the AE-QoL total score.

CONCLUSIONS

Angioedema Quality of Life Questionnaire is the first angioedema-specific QoL questionnaire. It is a short, valid and reliable instrument that may serve as a valuable tool in future clinical studies and in routine patient care.