Pearls and pitfalls in the diagnosis of hereditary angioedema

Hereditary angioedema is a very disabling and even life-threatening chronic condition. A timely and proper diagnosis of the condition is critical in disease management. Unfortunately, there is the potential for misdiagnosis when using the current laboratory diagnostic tools. Physicians should understand the limitations of each diagnostic assay and judiciously establish this life-altering diagnosis.

Recurrent Acute Abdomen as the Main Manifestation of Hereditary Angioedema

A diagnosis of hereditary angioedema is usually made with recurrent episodes of swelling of the subcutaneous tissue with a family history. We herein report a case in which recurrent acute abdomen was the main manifestation of hereditary angioedema. A 45-year-old womon presented with a 10-year history of recurrent severe abdominal pain. Abdominal computed tomography revealed remarkable submucosal edema of the ileum. A blood examination revealed grossly reduced complement C4 and CH50 with deficiency of C1-inhibitor. Genetic testing revealed a heterozygous nonsense mutation of the SERPING1 gene, and a diagnosis of hereditary angioedema was made. Hereditary angioedema should be listed as a differential diagnosis of recurrent acute abdomen.

New and evolving therapies for hereditary angioedema

Hereditary angioedema (HAE) is a rare, autosomal dominant, genetic disorder associated with a deficiency in C1 inhibitor protein. HAE is characterized by recurrent and unpredictable episodes of swelling of the extremities, abdomen, face, and upper airway. There are several newly approved drugs as well as investigational products that are currently under study for the management of patients with HAE, with the potential to optimize care and improve quality of life for patients with HAE. We reviewed the evolution of HAE treatment options in the United States and discussed mechanisms of action, routes of administration, and efficacy of these therapies.

Treatment of Hereditary Angioedema Attacks with Icatibant and Recombinant C1 Inhibitor During Pregnancy

PURPOSE

Hereditary angioedema (HAE) is a rare disease caused by a C1 inhibitor (C1-INH) deficit. Clinically, HAE is manifested by repeated episodes of localized subcutaneous or submucosal oedema attacks. Managing HAE patients in pregnancy is challenging, since there are only limited data on the safety and efficacy of various therapeutic approaches.

METHODS

We present our clinical experience treating acute HAE attacks during pregnancy in six consecutive patients.

RESULTS

During the pregnancies, 79 HAE attacks occurred. The most frequent were abdominal 53 (67.1%) followed by peripheral 21 (26.6%), facial 10 (12.7%), and laryngeal 10 (12.7%) oedemas; 13 (16.5%) attacks were combined. Fifty (63.3%) attacks were treated with recombinant human C1-INH (rhC1-INH); 17 (21.5%) with plasma-derived, pasteurized, nanofiltered C1-INH (pnfC1-INH); 13 (16.5%) with icatibant; and 1 (1.3%) with plasma-derived, nanofiltered C1-INH (nfC1-INH). Treatment had to be repeated in 5 attacks (6.3%). All six deliveries (one caesarean section and five spontaneous vaginal deliveries) were complication free. All pregnancies went to the full term and the patients delivered healthy babies with a birth weight ranging from 2850 to 3690 g. No congenital abnormalities were detected in the neonates. No abortions occurred.

CONCLUSIONS

Our results show good C1-INH or icatibant treatment efficacy for HAE attacks in pregnancy. The treatment by the first drug used was effective in 93.7% of all attacks. In 6.3% of attacks, a second treatment had to be used. No adverse effects were observed.

The complex alteration in the network of IL-17-type cytokines in patients with hereditary angioedema

Hereditary angioedema (HAE) is a rare autosomic-dominant disorder characterized by a deficiency of C1 esterase inhibitor which causes episodic swellings of subcutaneous tissues, bowel walls and upper airways that are disabling and potentially life-threatening. We evaluated n = 17 patients with confirmed HAE diagnosis during attack and remission state and n = 19 healthy subjects. The samples were tested for a panel of IL (Interleukin)-17-type cytokines (IL-1β, IL-6, IL-10, granulocyte-macrophage colony stimulating factor (GM-CSF), IL-17, IL-21, IL-22, IL-23) and transforming growth factor-beta (TGF-β) subtypes. Data indicate that there are variations of cytokine levels in HAE subjects comparing the condition during the crisis respect to the value in the remission phase, in particular type 17 signature cytokines are increased, whereas IL-23 is unmodified and TGF-β3 is significantly reduced. When comparing healthy and HAE subjects in the remission state, we found a significant difference for IL-17, GM-CSF, IL-21, TGF-β1 and TGF-β2 cytokines. These results confirm and extend our previous findings indicating that in HAE there is operating an inflammatory activation process, which involves also T helper 17 (Th17) cytokines and TGF-β isoforms, associated with localized angioedema attacks and characterized by elevated bradykinin levels.

Severity of hereditary angioedema, prevalence, and diagnostic considerations

Hereditary angioedema (HAE) is a rare disorder, characterized by intermittent attacks of swelling in any part of the body, without the presence of hives. This lifelong disease typically presents in the first 2 decades of life, and is commonly associated with a deficiency in functional C1 esterase inhibitor (C1-INH) activity. C1-INH levels may be decreased or normal, with an accompanied decrease in functionality, depending on the type of HAE present. The frequency and severity of attacks are highly variable among patients with HAE, but can have a significant impact on a patient's quality of life, and may be fatal if not properly managed. Early diagnosis of the disease can lead to the development of an individualized treatment plan to assist with prevention and management of angiodema attacks. Delays in diagnosis remain, as healthcare professionals often fail to include HAE in the differential diagnosis when patients present with attacks, and patients therefore often go undiagnosed or are misdiagnosed for several years before a diagnosis of HAE is made. It is important for providers to recognize the most common clinical features of HAE and how to evaluate patients to effectively diagnose, prevent, and treat future attacks.

Icatibant Outcome Survey in Patients with Hereditary Angioedema: Experience in Israel Compared with Other Countries

BACKGROUND

Management of patients with hereditary angioedema with C1-inhibitor deficiency (C1-INH-HAE) is evolving worldwide. Evaluating the Israeli experience may provide valuable insights.

OBJECTIVES

To compare demographics and icatibant treatment patterns and outcomes in patients with C1-INH-HAE enrolled in the Icatibant Outcome Survey (IOS) in Israel with those in other countries.

METHODS

The IOS is an ongoing observational study that prospectively monitors real-world icatibant safety/tolerability and treatment outcomes.

RESULTS

By July 2016, 58 patients from Israel and 594 patients from other countries were enrolled. Median age at diagnosis (16.7 vs. 21.3 years, P = 0.036) and median delay between symptom onset and diagnosis (0.8 vs. 6.6 years, P = 0.025) were lower in Israel compared with other countries, respectively. Differences in attack severity were not significant (P = 0.156); however, during follow-up, Israeli patients were less likely to miss > 7 days of work/school due to C1-INH-HAE-related complications (P = 0.007). A trend was also shown in Israel for earlier time to treatment (median 0.5 vs. 1.3 hours, P = 0.076), attack duration was shorter (median 5.0 vs. 9.0 hours, P = 0.026), and patients more often self-administered icatibant (97.2% vs. 87.5%, P = 0.003), respectively. However, Israeli patients were less likely to treat attacks (P = 0.036). Whereas patients in Israel reported exclusive use of danazol for long-term prophylaxis, those in other countries used various agents, including C1-INH.

CONCLUSIONS

Recognition of C1-INH-HAE and timeliness of icatibant treatment appear more favorable, and attack duration shorter, in Israel compared with other countries.

Clinical Features of Hereditary and Mast Cell-mediated Angioedema Focusing on the Differential Diagnosis in Japanese Patients

Objective The present study was designed to identify the clinical characteristics that permit the differential diagnosis of hereditary angioedema (HAE) and mast cell-mediated angioedema (Mast-AE) during the first consultation. Methods The medical histories and laboratory data of 46 patients with HAE and 41 patients with Mast-AE were compared. Results The average age of onset in the HAE group (19.8±9.0 years) was significantly lower than that in the Mast-AE group (35.2±12.0 years). The incidence of familial angioedema (AE) in the HAE group (73.9%) was significantly higher than that in the Mast-AE group (9.7%). The frequency of history of AE in the extremities, larynx, or gastrointestinal tract was significantly higher in the HAE group. The frequency of AE episodes of the lips and eyelids was significantly lower in the HAE group. The serum C4 concentration and CH50 titer were lower than the normal limit in 91.3% and 45.6% of the patients in the HAE group, respectively; in Mast-AE group the serum C4 concentration and CH50 titer were significantly lower than the normal limit in 4.8% and 0% of the patients, the difference between the two groups was statistically significant. A C1-inhibitor (C1-INH) activity level of <50% was observed in all of the HAE patients, but none of the Mast-AE patients. The mean serum IgE titer in the HAE group (120.8±130.5 IU/mL) was significantly lower than that in the Mast-AE group (262.2±314.9 IU/mL). Conclusion The parameters within the patients' medical histories, such as the age at the onset of AE, a family history of AE, and the locations of past AE episodes are critical for the successful diagnosis of the disease. Measurements of the C4 and C1-INH activity are very useful for differential diagnosis of HAE from Mast-AE.

[Allergology and clinical immunology]

Hereditary angioedema (HA) is a disabling and potentially fatal condition. The management of HA includes treatment of acute attacks, short-term prophylaxis to prevent an attack, and long-term prophylaxis to minimize the frequency and severity of recurrent attacks. In this article, we will present new therapeutic alternatives for long term prophylaxis. Glucocorticoids (GC) usage leads to a number of severe side-effects. In giant cell arteritis, the use of tocilizumab in conjunction with low doses of GC reduces the number of relapses. In ANCA-associated vasculitis the use of an anti-C5R (avacopan) alone or in conjunction with low doses of GC results in similar remission rates to those induced by high dose GC.

Brazilian Guidelines for Hereditary Angioedema Management - 2017 Update Part 1: Definition, Classification and Diagnosis

Hereditary angioedema is an autosomal dominant disease characterized by recurrent angioedema attacks with the involvement of multiple organs. The disease is unknown to many health professionals and is therefore underdiagnosed. Patients who are not adequately diagnosed and treated have an estimated mortality rate ranging from 25% to 40% due to asphyxiation by laryngeal angioedema. Intestinal angioedema is another important and incapacitating presentation that may be the main or only manifestation during an attack. In this article, a group of experts from the "Associação Brasileira de Alergia e Imunologia (ASBAI)" and the "Grupo de Estudos Brasileiro em Angioedema Hereditário (GEBRAEH)" has updated the Brazilian guidelines for the diagnosis and treatment of hereditary angioedema.

Screening for hereditary angioedema (HAE) at 13 emergency centers in Osaka, Japan: A prospective observational study

Hereditary angioedema (HAE) with deficiency of C1 inhibitor (C1-INH) is an autosomal-dominant disease characterized by recurrent episodes of potentially life-threatening angioedema. The objective is to study the incidence of HAE among patients who visit the emergency department.This was a 3-year prospective observational screening study involving 13 urban tertiary emergency centers in Osaka prefecture, Japan. Patients were included if they met the following criteria: unexplained edema of the body, upper airway obstruction accompanied by edema, anaphylaxis, acute abdomen with intestinal edema (including ileus and acute pancreatitis), or asthma attack. C1-INH activity and C4 level were measured at the time of emergency department admission during the period between July 2011 and June 2014.This study comprised 66 patients with a median age of 54.0 (IQR: 37.5-68.3) years. Three patients were newly diagnosed as having HAE, and 1 patient had already been diagnosed as having HAE. C1-INH activity levels of the patients with HAE were below the detection limit (<25%), whereas those of non-HAE patients (n = 62) were 106% (IQR: 85.5%-127.0%) (normal range, 70%-130%). The median level of C4 was significantly lower in the patients with HAE compared with those without HAE (1.2 [IQR: 1-3] mg/dL vs 22 [IQR: 16.5-29.5] mg/dL, P < 0.01) (normal range, 17-45 mg/dL).Three patients with undiagnosed HAE were diagnosed as having HAE in the emergency department during the 3-year period. If patients have signs and symptoms suspicious of HAE, the levels of C1-INH activity and C4 should be measured.

[Angioedema and the role of bradykinins: new treatments and implications in patients with heart failure]

The definition of angioedema is an edema of subcutaneous and submucosal tissues due to increased vascular permeability and fluid extravasation. It can affect different areas, including extremities, genitals, upper airways and intestinal mucosa. The symptoms are disabling and this condition can be fatal if it involves the larynx. We can distinguish different forms of angioedema (hereditary and acquired) with different pathogenetic mechanisms, therefore responding to different treatments. Bradykinin-mediated angioedema (such as hereditary angioedema due to C1-inhibitor deficiency) does not respond to the standard therapy used for histamine-mediated angioedema. These forms should be immediately recognized and specific treatment should be used. In addition, when a patient manifests hypotension not responding to fluid replacement and associated with diffuse edema, hypoalbuminemia and hemoconcentration, we should consider the diagnosis of idiopathic systemic capillary leak syndrome, a very rare but fatal condition.

The Janus faces of acquired angioedema: C1-inhibitor deficiency, lymphoproliferation and autoimmunity

Several clinical and biological features of lymphoproliferative diseases have been associated with an increased risk of developing autoimmune manifestations. Acquired deficiency of C1-inhibitor (C1-INH) (AAE) is a rare syndrome clinically similar to hereditary angioedema (HAE) characterized by local increase in vascular permeability (angioedema) of the skin and the gastrointestinal and oro-pharyngo-laryngeal mucosa. Bradykinin, a potent vasoactive peptide, released from high molecular weight kininogen when it is cleaved by plasma kallikrein (a serine protease controlled by C1-INH), is the mediator of symptoms. In total 46% of AAE patients carry an underlying hematological disorder including monoclonal gammopathy of uncertain significance (MGUS) or B cell malignancies. However, 74% of AAE patients have anti-C1-INH autoantibodies without hematological, clinical or instrumental evidence of lymphoproliferative disease. Unlike HAE patients, AAE patients usually have late-onset symptoms, do not have a family history of angioedema and present variable response to treatment due to the hypercatabolism of C1-INH. Experiments show that C1-INH and/or the classical complement pathway were consumed by the neoplastic lymphatic tissues and/or anti-C1-INH neutralizing autoantibodies. Therapy of AAE follows two directions: 1) prevention/reversal of the symptoms of angioedema; and 2) treatment of the associated disease. Different forms of B cell disorders coexist and/or evolve into each other in AAE and seem to be dominated by an altered control of B cell proliferation, thus AAE represents an example of the strict link between autoimmunity and lymphoproliferation.

Clinical presentation, pathophysiology, diagnosis, and treatment of acquired and hereditary angioedema: Exploring state-of-the-art therapies in RI

Hereditary and acquired angioedema are potentially life-threatening diseases characterized by spontaneous episodes of subcutaneous and submucosal swelling of face, lips, oral cavity, larynx, and GI tract. Hereditary angioedema (HAE) usually presents within the first and second decades of life, whereas acquired angioedema presents in adults after 40 years of age. These clinical symptoms together with reduced C1 inhibitor levels and/or activity can usually confirm the diagnosis. In recent years, multiple novel therapies for treating hereditary angioedema have emerged including C1 inhibitor concentrates, ecallantide/kallikrein inhibitor, and icatibant/bradykinin receptor antagonist. This article reviews the clinical presentation, diagnosis, treatment, and prophylaxis of HAE. Lastly, this article takes into consideration that, in reality, acute care treatment can often be limited by each hospital's formulary, included is a review of HAE treatments available at the nine major hospitals in Rhode Island. [Full article available at http://rimed.org/rimedicaljournal-2016-06.asp, free with no login].

Hereditary Angioedema in Swedish Adults: Report From the National Cohort

Hereditary angioedema (HAE) is rare, disabling and sometimes life-threatening. The aim of this study is to describe its prevalence, symptomatology and treatment in Sweden. A total of 146 patients were identified; 110 adults and 36 children with HAE type I (n = 136) or II (n = 10), giving a minimal HAE prevalence of 1.54/100,000. All patients received a written questionnaire followed by a structured telephone interview. This report focuses on the 102 adults who responded. Females reported 19 attacks in the previous year vs. 9 for males (p < 0.01), and females reported 10 days of sick leave vs. 4 days for males (p < 0.05). For all treated acute attacks, plasma-derived C1-inhibitor concentrate (pdC1INH) (used in 27% of patients) had a good effect. For maintenance treatment, 43% used attenuated androgens and 8% used pdC1INH, which reduced their attack rate by more than 50%. In conclusion, the minimal HAE prevalence in Sweden was 1.54/100,000. HAE affected females more severely. Attenuated androgens and pdC1INH had a good effect on preventing attacks.

Hereditary angio-oedema with C1 inhibitor deficiency: Characteristics and diagnostic delay of Czech patients from one centre

BACKGROUND

Hereditary angio-oedema (HAE) is manifested by repeated episodes of localised subcutaneous or sub-mucosal oedema. Symptoms are extremely variable in frequency, localisation, and severity. Atypical or mild clinical symptoms of the disease may lead to erroneous diagnosis, causing diagnostic delay. The goal of this study was to assess how diagnostic delay has changed over 33 years at a single referral centre.

METHODS

We analysed diagnostic delay and first symptoms of HAE in patients who were diagnosed at an immunology department between 1980 and 2013. Patient's records were analysed.

RESULTS

The median diagnostic delay in 77 HAE type 1 and 2 patients was seven (range, 0-42) years. The difference observed in diagnostic delay between probands (18 [0-42] years) and others (1 [0-37] year) was significant (p<0.001). Our data show a significant negative correlation between the length of diagnostic delay and the year of diagnosis in our group of patients (p=0.024). The median age of first symptoms among all HAE patients (N=64) was 17 (1-40) years. The first symptoms of HAE in 64 patients were analysed. Twenty-six patients had abdominal, seventeen peripheral, five facial, two urogenital, and three had laryngeal oedema as the first manifestation of the disease. The last death that was attributed to HAE was in 1977.

CONCLUSIONS

Our observations demonstrate improved awareness of HAE among physicians, as documented by the significant decrease in diagnostic delay. It is believed that earlier treatment will improve patient quality of life and life expectancy.

Urticaria and Prodromal Symptoms Including Erythema Marginatum in Danish Patients with Hereditary Angioedema

Erythema marginatum is a characteristic skin rash seen in patients with hereditary angioedema (HAE); however, it can be confused with urticaria, leading to delay in correct diagnosis. The aim of this study was to clarify how often erythema marginatum is misinterpreted as urticaria, potentially leading physicians to refrain from testing for HAE. Few studies have been published on urticaria and prodromal symptoms in HAE, thus the incidence of these parameters were also investigated. A total of 87 patients affiliated to the national HAE Centre were included. Retrospective and prospective data on skin eruptions and prodromal symptoms were collected. Fifty-six percent of 87 patients had a positive history of erythema marginatum. Half of the patients had experienced erythema marginatum being misinterpreted as urticaria. The most prevalent other prodromal symptoms were other skin symptoms, malaise, psychological changes, fatigue and gastrointestinal symptoms. HAE patients with erythema marginatum have a longer diagnostic delay, presumably caused by misinterpretation of the rash as urticaria.