Clinical practice. Hereditary angioedema

Time Trade-Off Utilities for Hereditary Angioedema Health and Caregiver States

BACKGROUND

Hereditary angioedema (HAE) is an inherited chronic rare disease characterised by recurrent swelling attacks that are associated with significant physical and psychological burden. There is limited understanding of the effect of attack location on this burden and of caregiver burden.

OBJECTIVE

Our objective was to capture the relative burden of HAE health and caregiver states, including different attack locations, through a time trade-off (TTO) analysis involving participants from the general public.

METHODS

Qualitative interviews were undertaken to inform vignette development for the TTO study, including vignettes for abdominal, facial, hand and laryngeal attack health states, and an attack-free and caregiver state. Members of the general public in England rated vignettes in TTO interviews, which included a visual analogue scale (VAS) component. For the development of the health state vignettes, qualitative interviews with 15 patients, 5 caregivers and 1 clinical expert were performed. TTO analysis was based on vignette valuation completed by 100 members of the general public.

RESULTS

The TTO values were as follows: attack-free, 0.783 (standard deviation [SD] 0.316); hand: 0.582 (SD 0.380); facial: 0.483 (SD 0.448); abdominal: 0.345 (SD 0.458); and laryngeal: 0.128 (SD 0.529). The caregiver rating was 0.762 (SD 0.303). V' scores were similar and consistent with TTO values.

CONCLUSION

TTO utility values demonstrate that HAE places a significant burden on patients, which is influenced by attack location, and on caregivers. These utility weights can provide important information on quality of life for future economic evaluations of treatments.

Specific Targeting of Plasma Kallikrein for Treatment of Hereditary Angioedema: A Revolutionary Decade

Hereditary angioedema (HAE) is a rare, chronic, genetic disease that presents with nonpruritic angioedema of the face, extremities, airway (can be life-threatening), genitourinary system, and abdomen. These symptoms can significantly impair daily activities. Hereditary angioedema is classified into HAE owing to a deficiency of functional C1INH (HAE-C1INH) or HAE with normal C1INH (HAE-nl-C1INH). Both type I and II HAE-C1INH result from inherited or spontaneous mutations in the SERPING1 gene, which encodes for C1INH. These mutations result in C1INH dysfunction, leading to uncontrolled plasma kallikrein activity with excessive bradykinin production. Bradykinin receptor activation leads to vasodilation, increased vascular permeability, and smooth muscle contractions, resulting in submucosal angioedema through fluid extravasation. Hereditary angioedema nl-C1INH is caused by either a known or unknown genetic mutation. The underlying mechanism of HAE-nl-C1INH is less well understood but is thought to be related to bradykinin signaling. Plasma kallikrein inhibitors have been developed to inhibit the kallikrein-kinin pathway to prevent (prophylactic) and treat on-demand (acute) HAE attacks. Several of these medications are delivered through subcutaneous or intravenous injection, although new and emerging therapies include oral formulations. This article provides a historical review and describes the evolving landscape of available kallikrein inhibitors to treat HAE-C1INH.

Pediatric Emergency Department Management of C1 Inhibitor Deficiency

INTRODUCTION

C1 inhibitor deficiency is a rare, potentially life-threatening syndrome. Acute attacks of angioedema may occur at any time, so the emergency department (ED) constitutes an indispensable component of its care.

AIM

To describe the reasons for consultation by children with C1 inhibitor deficiency at the ED, as well as its management and complications.

PATIENTS AND METHODS

This is a longitudinal retrospective study conducted in a pediatric ED of a tertiary care hospital in Madrid. The study includes children with C1 inhibitor deficiency, aged 0 to 16 years, who had consulted the ED for whatever reason, over a span of 9 years (2011-2020). Analyzed data include the following: age, sex, type of disease, reason for query, complementary examinations, established diagnosis, treatment, number of visits to the ED, length of ED stay, and admissions.

RESULTS

Sixteen patients, amounting a total of 83 ED visits, were analyzed. Fifty-six percent were boys, and the median age was 6.9 years (5 months to 15.9 years). The median and mean of number of visits to the ED per patient was 2 (1-22) and 5.2 ± 6.11, respectively. There were 85.5% of the ED visits initially attributed to acute angioedema attacks. Additional tests were conducted in 30.1%, and 31.3% required C1 inhibitor concentrate. Three episodes required hospital admission (3.6%), and there were no complications. The stay in the ED was longer for patients who needed specific intravenous treatment.

CONCLUSIONS

C1 inhibitor deficiency is a rare disease that may require ED care. The main reasons for ED visits were respiratory problems, and the main location of the acute attacks of angioedema were abdominal and cutaneous. Almost one third of the ED visits needed specific treatment, resulting in longer stays. A proper management in the ED and the specific treatment with C1 inhibitor concentrate were effective in 96.2% of the acute attacks of angioedema. Knowledge of this disease in the ED is key to prevent complications.

Oral Surgery Procedures in a Patient Affected by Hereditary Angioedema Type I

Hereditary Angioedema (HAE) is a rare disease characterized by a deficiency or a reduced function of the plasma protein C1 esterase inhibitor (C1-INH), which is involved in the downregulation of several inflammatory pathways. Patients affected by HAE suffer from episodic swellings of subcutaneous or submucosal tissues. Swellings can be caused by stress or dental and surgical procedures and can be life-threatening if the airways are involved. We have reported a clinical case of a patient affected by HAE type I who underwent oral surgery procedures under a short-term prophylaxis with C1-INH plasma-derived concentrate. The patient underwent a cyst removal, multiple tooth extractions, and an excisional biopsy with a prophylaxis with C1-INH plasma-derived concentrate and was hospitalized for 36 hours after the surgery to be monitored for possible HAE attacks. During the hospitalization, the patient did not show signs of swelling nor of HAE attacks. At 14 and 28 days after the surgery, the patient presented a good surgical healing. The prophylactic intravenous infusion of C1-INH concentrate was successful in preventing acute HAE attacks after oral surgery procedures.

Guidelines for management of hereditary angioedema: What is new? What is missing?

Background: Hereditary angioedema is an autosomal dominant disease that presents with recurrent episodic swelling of the submucosal and/or subcutaneous tissues of the cutaneous, gastrointestinal, and respiratory systems. Evaluation and treatment guidelines have been published nationally and internationally to aid the treating provider. Methods: A review of the most cited and most recent updated guidelines was undertaken to review key points and to explore real-world feasibility of incorporating them into clinical practice. The International World Allergy Organization/European Academy of Allergy and Clinical Immunology (WAO/EAACI) Guideline for the Management of Angioedema - The 2017 Revision and Update, and the consensus reports from the Hereditary Angioedema International Working Group, the Joint Task Force on Practice Parameters focused practice parameter update, and the most recently updated US HAEA Medical Advisory Board 2020 Guidelines for the Management of Hereditary Angioedema were reviewed and summarized. Results: Key points that have been consistent throughout the guidelines include recommendations for evaluation and classification of hereditary angioedema as well as evidence-based guidelines for treatment. Further attention is required on the evaluation and continuous assessment of the burden of illness and quality of life (QoL). Conclusion: The guidelines for management of hereditary angioedema provide a framework for the clinician. However, the physician-patient dialog with regard to the patient disease experience, which includes attack frequency, severity, and Qol, must be continually assessed.

Preventive Treatment of Hereditary Angioedema: A Review of Phase III Clinical Trial Data for Subcutaneous C1 Inhibitor and Relevance for Patient Management

PURPOSE

Hereditary angioedema (HAE), most often caused by a genetically mediated deficiency in the activity of C1 inhibitor (C1INH) protein, is characterized clinically by recurrent episodes of localized swelling without wheals. HAE attacks can be painful, debilitating, and even fatal, resulting in physical discomfort, emotional stress, and interruptions of work, school, and/or social activities, all of which can affect health-related quality of life (HRQoL). Subcutaneous C1INH (C1INH[SC]) is recommended as a first-line option for long-term prophylaxis (LTP) in HAE. This narrative review provides a concise but comprehensive overview of all published data generated from the pivotal Phase III Clinical Study for Optimal Management of Preventing Angioedema With Low-Volume Subcutaneous C1-Inhibitor Replacement Therapy (COMPACT) study program, which evaluated the use of C1INH(SC) as LTP.

METHODS

A PubMed search was performed using the search terms subcutaneous C1 inhibitor plus COMPACT with no filters, and another search was performed using the term subcutaneous C1 inhibitor, with output limited to clinical trial data only. All publications that reported data generated during the Phase III COMPACT study were included. Data presentation focused on the US Food and Drug Administration-approved dose of 60 IU/kg.

FINDINGS

The search strategy identified a total of 11 publications that reported data and analyses from the Phase III COMPACT study. Publications reported overall findings from the double-blind, placebo-controlled, crossover COMPACT study and a subsequent long-term open-label extension (OLE) study. Other published analyses included pharmacokinetic/pharmacodynamic data, HRQoL assessments, and findings in patient subgroups including women, pediatric patients, and patients ≥65 years of age. Subgroup analyses reported good safety and efficacy profiles among age-based subgroups from the COMPACT OLE, including pediatric patients, patients ≥65 years of age with comorbidities, and among female patients, despite a tendency for HAE to be more severe in women. A number of significant HRQoL improvements were noted with C1INH(SC) use, including better overall health status, less anxiety, and less work- and activity-related impairment versus placebo (double-blind study), and compared with baseline (OLE).

IMPLICATIONS

This review provides a concise overview of all published COMPACT study data with C1INH(SC). The data reviewed here portray a high level of efficacy and tolerability with C1INH(SC), even during periods of treatment that exceed 2 years, which does not appear to vary based on patient age or sex. Clinically relevant improvements in multiple facets of HRQoL were also reported, including better overall HRQoL, less anxiety and depression, and less disruptions in work attendance and productivity. These data should be useful for assessing the appropriateness of C1INH(SC) therapy for individual patients.

Hereditary Angioedema: A Gynecology and Obstetrics Perspective

Hereditary angioedema is an autosomal dominant genetic disease that causes tissue edema mediated by bradykinin. The angioedema attacks have several triggers including stress, trauma, infection, and increased estrogens levels. This explains the greater incidence and clinical severity in women, which are usually asymptomatic until puberty, when the attacks begin to occur. It may involve multiple locations on the body, leading to complications, such as surgical intervention prompt by severe acute abdominal pain, and laryngeal edema that can culminate in death from asphyxia. This is of particular concern as this angioedema does not respond to life-saving medications commonly used in its treatment, namely, high doses of second-generation antihistamines, corticosteroids, and epinephrine. Hereditary angioedema attacks are treated with specific medication that includes icatibant, ecallantide, and C1 inhibitor, the latter being also used in short-term and long-term prophylaxis. There are other pharmacological strategies for long-term prophylaxis like lanadelumab, danazol, stanozolol, aminocaproic acid, and tranexamic acid. During pregnancy and lactation, the preferred treatment and prophylaxis is C1 inhibitor.

We report a case of hereditary angioedema describing its chronological evolution over a period of a woman's life, and highlighting some of the specificities of this pathology that intersect with the specialty of Obstetrics and Gynecology. Our aim is to draw attention to these particularities, namely the triggering factors of crisis, the need for high suspicion of the diagnosis, and the treatment and prophylaxis options for pregnant and non-pregnant women that can make the difference between life and death. To achieve a favorable outcome, the multidisciplinary teamwork between the specialties of Immunoallergology and Obstetrics and Gynecology was crucial.

Physicochemical and Biological Characterization of rhC1INH Expressed in CHO Cells

The disfunction or deficiency of the C1 esterase inhibitor (C1INH) is associated with hereditary or acquired angioedema (HAE/AAE), a rare life-threatening condition characterized by swelling in the skin, respiratory and gastrointestinal tracts. The current treatment options may carry the risks of either viral infection (plasma-derived Berinert^®) or immune reaction (human recombinant C1INH from rabbit milk, Ruconest^®). This study describes the physicochemical and biological characterization of a novel recombinant human C1 esterase inhibitor (rhC1INH) from Chinese hamster ovary (CHO) cells for the treatment of hereditary angioedema compared to the marketed products Berinert^® and Ruconest^®. The mass spectrometry results of total deglycosylated rhC1INH revealed a protein with a molecular mass of 52,846 Da. Almost full sequence coverage (98.6%) by nanoLC-MS/MS peptide mapping was achieved. The purity and C1s inhibitory activity of rhC1INH from CHO cells are comparable with Ruconest^®, although we found differences in charge isoforms distribution, intact mass values, and N-glycans profile. Comparison of the specific activity (IC₅₀ value) of the rhC1INH with human C1 esterase inhibitor from blood serum showed similar inhibitory properties. These data allow us to conclude that the novel rhC1INH molecule could become a potential therapeutic option for patients with HAE/AAE.

Subclinical Signs of Retinal Involvement in Hereditary Angioedema

To explore retinal abnormalities using spectral domain optical coherence tomography (SD-OCT) and OCT-angiography (OCT-A) in a highly selective cohort of patients with type I hereditary angioedema (HAE). This prospective case-control study included 40 type I HAE patients and 40 age-/sex-matched healthy subjects (HC). All participants underwent SD-OCT-scanning of retinal posterior pole (PP), peripapillary retinal nerve fiber layer (pRNFL), and optic nerve head (ONH). Superficial/deep capillary density was analyzed by OCT-A. A total of 80 eyes from 40 HAE and 40 eyes from HC were evaluated. The pRNFL was thicker in HAE than in HC in nasal superior (p < 0.0001) and temporal quadrants (p = 0.0005 left, p = 0.003 right). The ONH thickness in HAE patients was greater than in HC in the nasal (p = 0.008 left, p = 0.01 right), temporal (p = 0.0005 left, p = 0.003 right), temporal inferior (p = 0.007 left, p = 0.0008 right), and global (p = 0.005 left, p = 0.007 right) scans. Compared to HC, HAE showed a lower capillary density in both superficial (p = 0.001 left, p = 0.006 right) and deep (p = 0.008 left, p = 0.004 right) whole images, and superficial (p = 0.03 left) and deep parafoveal (p = 0.007 left, p = 0.005 right) areas. Our findings documented subclinical retinal abnormalities in type I HAE, supporting a potential role of the retinal assessment by SD-OCT/OCT-A as a useful tool in the comprehensive care of HAE patients.

The multiomics landscape of serum exosomes during the development of sepsis

•

The study for the first time describes the profile of molecular dynamics in septic serum exosomes.

•

We provide a new direction into proteasome-mediated protein degradation in septic serum exosomes.

•

IL-10 delivery by septic exosomes may play a vital role in alleviation of AKI of CLP mice.

•

Septic serum exosomes participate in the modulation of sepsis by regulating vitamin metabolism.

•

The molecular mechanisms proposed in the study may provide helpful insights for the therapy of sepsis.

Introduction

Sepsis is an infection-induced severe inflammatory disorder leading to multiple organ dysfunction. It remains a highly lethal condition for which early diagnosis and therapy achieve unsatisfactory results. Circulating exosomes containing biomarkers and mediators of sepsis have recently received attention, but the progress has been far from optimal.

Objectives

The present study focuses on the profiles of molecular dynamics in serum exosomes and explores the potential molecular mechanisms on serum exosomes during the process of sepsis.

Methods

We used high-performance liquid chromatography-tandem mass spectrometry and RNA-seq to detect the dynamic profiles of exosome proteins and RNAs (including mRNAs, lncRNAs and miRNAs) in serum exosomes from 3 healthy individuals and 9 septic patients at the different stages. Then integrative multiomics analyses were performed and the results were validated by qRT-PCR, LiquiChip assay and metabolomics analysis on mice subjected to cecal ligation and puncture (CLP) modeling.

Results

A total of 354 proteins, 195 mRNAs, 82 lncRNAs and 55 miRNAs were identified as differentially expressed molecules in serum exosomes from septic patients. Integrative multiomics analysis showed that exosome components were associated with cytokine storm, complement and clotting cascades, the endothelial barrier, 20S proteasome-dependent protein degradation and vitamin metabolism. Importantly, pretreatment with serum exosomes derived from mice subjected to CLP significantly restrained proinflammatory cytokine expression and alleviated tissue injury in septic mice. Further metabolomics analysis demonstrated that pretreatment with septic serum exosomes significantly affected the metabolites associated with vitamin digestion and absorption in CLP mice.

Conclusion

Our study for the first time describes the landscape of the molecular dynamics of serum exosomes during the development of sepsis and proposes some hypothetical molecular mechanisms by integrative multiomics analysis, which may provide helpful diagnostic and therapeutic insights for the ongoing battle against sepsis.

First Census of Patients with Hereditary Angioedema in the Canary Islands

Hereditary angioedema (HAE) is a rare genetic condition whose main symptoms are recurrent swelling in the skin, mucosa, and internal organs. Recent studies suggested that the regulation of the inflammatory response and the complement cascade are two of the pathways significantly enriched in the Canary Islands, Spain. Here, we describe the first HAE patient series in this region. Forty-one patients (33 F, 8 M) and nine healthy relatives belonging to twenty-nine families were recruited for this study, obtaining their clinical and demographic features using a data collection form, as well as blood samples for biochemical analysis. The mean age of patients was 36.8 years (ranging from 4 to 72 years). Positive family history of HAE was reported in 13 patients (32.5%), and a mean diagnosis delay of 7.9 (±12.5) years was estimated, ranging from months to 50 years. Cutaneous edema was the most common symptom (53.6%), while airway symptoms was present in 11 patients. Prophylactic treatment was indicated for 23 patients, while 14 also require on-demand rescue treatment. We estimate a minimum prevalence of 1.25:100,000 for HAE due to C1-INH deficiency or dysfunction in the Canary Islands, which is higher than the estimates for mainland Spanish populations. HAE continues to be a disease poorly recognized by health care professionals due to its confusing symptoms, leading to longer diagnosis delay. Altogether, the evidence reinforces the need for a rapid and accurate diagnosis and precision medicine-based studies to improve the patient's quality of life.

C1-Inhibitor: Structure, Functional Diversity and Therapeutic Development

Human C1-Inhibitor (C1INH), also known as C1-esterase inhibitor, is an important multifunctional plasma glycoprotein that is uniquely involved in a regulatory network of complement, contact, coagulation, and fibrinolytic systems. C1INH belongs to a superfamily of serine proteinase inhibitor (serpins) and exhibits its inhibitory activities towards several target proteases of plasmatic cascades, operating as a major anti-inflammatory protein in the circulation. In addition to its inhibitory activities, C1INH is also involved in non-inhibitory interactions with some endogenous proteins, polyanions, cells and infectious agents. While C1INH is essential for multiple physiological processes, it is better known for its deficiency with regards to Hereditary Angioedema (HAE), a rare autosomal dominant disease clinically manifested by recurrent acute attacks of increased vascular permeability and edema. Since the link was first established between functional C1INH deficiency in plasma and HAE in the 1960s, tremendous progress has been made in the biochemical characterization of C1INH and its therapeutic development for replacement therapies in patients with C1INH-dependent HAE. Various C1INH biological activities, recent advances in the HAE-targeted therapies, and availability of C1INH commercial products have prompted intensive investigation of the C1INH potential for treatment of clinical conditions other than HAE. This article provides an updated overview of the structure and biological activities of C1INH, its role in HAE pathogenesis, and recent advances in the research and therapeutic development of C1INH; it also considers some trends for using C1INH therapeutic preparations for applications other than angioedema, from sepsis and endotoxin shock to severe thrombotic complications in COVID-19 patients.

Risk Factors Associated with Intubation and Readmissions in patients with Angioedema: A Single Center Experience

BACKGROUND

Given the heterogeneity of etiologies, pathophysiology and presentation of angioedema, variations in clinical outcomes, such as intubation and hospital readmissions, need further clarification.

OBJECTIVE

To determine factors associated with intubation and hospital readmissions in patients with angioedema.

METHODS

Retrospective study of patients evaluated with a diagnosis of angioedema over a 6year period. Demographic and clinical data such as medication use, family history, comorbidities, and symptoms were recorded. Multivariable logistic regression was used to analyze factors associated with intubation, while Cox regression was used to analyze readmissions.

RESULTS

From 636 patients, the most common etiology of angioedema was angiotensin converting enzyme inhibitor (ACEI) induced at 58%. The overall mortality was 0.5%. After adjusting for gender, race, comorbidities, and type of angioedema, smoking (OR=1.79, 95% CI=1.10-2.93, p=0.02), calcium channel blocker (CCB) therapy (OR=1.91, 95% CI=1.18-3.10, p=0.009), histaminergic symptoms (OR=3.21, 95% CI=1.93-5.33, p<0.001) and age (OR=1.02, 95% CI=1.00-1.04, p=0.023) were independently associated with increased odds of intubation. Involvement of either the pharynx, larynx or tongue was associated with higher odds of intubation (OR=20.96, 95% CI=10.63-41.33, p<0.001). 10% of patients had a readmission for angioedema within 90 days and 75% occurred within 30 days. After Multivariable Cox Regression analysis, only COPD/asthma (OR=2.13, 95% CI=1.12-4.07, p=0.022) and ACEI related angioedema (OR=2.93, 95% CI=1.33-6.47, p=0.008) were significantly associated with readmissions.

CONCLUSION

Smoking, CCB use, histaminergic symptoms, age, and upper airway involvement were significantly associated with intubation. Presence of COPD/asthma and ACEI related angioedema were independently associated with increased odds of readmission.

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

Background

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

Methods

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

Results

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

Conclusions

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

Demographic and clinical characteristics of patients with hereditary angioedema in Canada

BACKGROUND

Data on the clinical and demographic features of Canadian patients with hereditary angioedema (HAE) are lacking.

OBJECTIVE

To describe the clinical and demographic features in a large Canadian HAE cohort and compare them with patients with HAE in other countries.

METHODS

An online questionnaire was distributed to the members of 2 Canadian HAE patient groups to collect information on demographics and HAE clinical characteristics. All participants 18 years of age or older with HAE type I or II were eligible. Frequency, location, prodromes, and triggers of HAE attacks, including types of HAE treatment, were characterized.

RESULTS

Among the 90 participants who completed the online survey, 57% self-identified as having HAE type 1 and 26% HAE type II. The average diagnostic delay was 11 years. In the preceding 6 months, 24% of the participants had no attacks and 35% experienced greater than 5 attacks. The most frequently affected regions of the body were the abdomen (83%), arms orlegs (63%), face (41%), and larynx or throat (41%). Approximately 87% of the participants reported having access to C1 inhibitor at home, and 69% reported using it for long-term prophylaxis.

CONCLUSION

Canadian patients with HAE share common clinical characteristics with patients with HAE in other countries. They had a delay in HAE diagnosis and a high burden of disease, as indicated by the high frequency of attacks in the preceding 6 months. This study provides a better understanding of the demographic and clinical characteristics of Canadian patients with HAE.

Long-term safety and effectiveness of berotralstat for hereditary angioedema: The open-label APeX-S study

BACKGROUND

Berotralstat (BCX7353) is an oral, once-daily inhibitor of plasma kallikrein recently approved for prevention of angioedema attacks in adults and adolescents with hereditary angioedema (HAE). The objective of this report is to summarize results from an interim analysis of an ongoing long-term safety study of berotralstat in patients with HAE.

METHODS

APeX-S is an ongoing, phase 2, open-label study conducted in 22 countries (ClinicalTrials.gov, NCT03472040). Eligible patients with a clinical diagnosis of HAE due to C1 inhibitor deficiency (HAE-C1-INH) were centrally allocated to receive berotralstat 150 or 110 mg once daily. The primary objective was to determine long-term safety and the secondary objective was to evaluate effectiveness.

RESULTS

Enrolled patients (N = 227) received berotralstat 150 mg (n = 127) or 110 mg (n = 100) once daily. The median (range) duration of exposure was 342 (11-540) and 307 (14-429) days for the 150-mg and 110-mg groups, respectively. Treatment-emergent adverse events (TEAEs) occurred in 91% (n = 206) of patients. The most common TEAEs across treatment groups were upper respiratory tract infection (n = 91, 40%), abdominal pain (n = 57, 25%), headache (n = 40, 18%), and diarrhea (n = 31, 14%) and were mostly mild to moderate. Fifty percent (n = 113) of patients had at least one drug-related adverse event (AE; 150 mg, n = 57 [45%]; 110 mg, n = 56 [56%]), and discontinuations due to AEs occurred in 19 (8%) patients (150 mg, n = 13 [10%]; 110 mg, n = 6 [6%]). Three (1.3%) patients experienced a drug-related serious TEAE. Among patients who received berotralstat through 48 weeks (150 mg, n = 73; 110 mg, n = 30), median HAE attack rates were low in month 1 (150 mg, 1.0 attacks/month; 110 mg, 0.5 attacks/month) and remained low through 12 months (0 attacks/month in both dose groups). Mean HAE attack rates followed a similar trend, and no evidence for patient tolerance to berotralstat emerged. In both dose groups, angioedema quality of life scores showed clinically meaningful changes from baseline.

CONCLUSIONS

In this analysis, both berotralstat doses, 150  and 110 mg once daily, were generally well tolerated. Effectiveness results support the durability and robustness of berotralstat as prophylactic therapy in patients with HAE.

TRIAL REGISTRATION

The study is registered with ClinicalTrials.gov (NCT03472040).

The Genetics of Hereditary Angioedema: A Review

Hereditary angioedema is a rare inherited disorder characterized by recurrent episodes of the accumulation of fluids outside of the blood vessels, causing rapid swelling of tissues in the hands, feet, limbs, face, intestinal tract, or airway. Mutations in SERPING1, the gene that encodes C1-INH (C1 esterase inhibitor), are responsible for the majority of cases of hereditary angioedema. C1 esterase inhibitor (C1-INH) is a major regulator of critical enzymes that are implicated in the cascades of bradykinin generation, which increases the vascular permeability and allows the flow of fluids into the extracellular space and results in angioedema. Moreover, a dominantly inherited disease has been described that has a similar clinical picture to C1-INH-HAE (Hereditary angioedema due to C1 inhibitor deficiency), but with normal C1-INH level and activity. This new type of HAE has no mutation in the SERPING1 gene and it is classified as nC1-INH-HAE (HAE with normal C1-INH). Currently mutations in six different genes have been identified as causing nC1-INH-HAE: factor XII (F12), plasminogen (PLG), angiopoietin 1 (ANGPT1), Kininogen 1 (KNG1), Myoferlin (MYOF), and heparan sulfate (HS)-glucosamine 3-O-sulfotransferase 6 (HS3ST6). In this review we aim to summarize the recent advances in genetic characterization of angioedema and possible future prospects in the identification of new genetic defects in HAE. We also provide an overview of diagnostic applications of genetic biomarkers using NGS technologies (Next Generation Sequencing).

Short-term prophylaxis for children and adolescents with hereditary angioedema

Background: Hereditary Angioedema (HAE) is a rare, autosomal dominant, life threatening disease, secondary to the deficiency of C1-inhibitor, dysfunction of C1-inhibitor or inadequate control of the contact pathway. Presentation includes recurrent swelling of the skin, upper airway and the abdomen. Trauma can precipitate attacks, which in the airway can lead to asphyxia. For this reason, short term prophylaxis (STP) may be indicated before medical, surgical and dental procedures. The goal of the manuscript is to review short term prophylaxis for children of all ages. Methods: We searched the following search words: children, pediatric, adolescent, plasma derived C1-inhibitor, recombinant C1-inhibitor, surgery, medical procedures, prophylaxis, dental, Hereditary Angioedema, tranexamic acid, androgens, fresh frozen plasma, short term prophylaxis, lanadelumab, subcutaneous C1-inhibitor in Google Scholar and in PubMed to develop our results. Results: STP should be discussed at every visit. Plans should be individualized based upon the procedure, therapies available and shared decision making with patient/parent. For high risk procedures plasma derived C1-inhibitor should be used at 20 units/kg just prior to the procedure. Alternative agents for STP include recombinant C1-inhibitor, fresh frozen plasma, androgens, or tranexamic acid. In all cases, with or without the use of STP, 2 doses of on-demand therapy should be available in case of an attack. Conclusion: Herein, we review the published data on STP for pediatric patients with HAE and discuss first-line options, and off label use of medications, as well as review the guidelines pertaining to short term prophylaxis.

Icatibant promotes patients' behavior modification associated with emergency room visits during an acute attack of hereditary angioedema

Hereditary angioedema due to C1-inhibitor (C1-INH) deficiency (HAE-C1-INH) induces an acute attack of angioedema. In 2018, icatibant available for self-possession and subcutaneous self-administration was licensed for on-demand treatment in addition to intravenous C1-INH administration in Japan. We retrospectively evaluated the percentage of attacks in critical parts at emergency room (ER) visits and the time until visiting ER for C1-INH administration before and after the initial prescription of icatibant. The percentage of attacks in critical parts at ER visits before the prescription was 69.2%, but that was 80.0% when patients visited ER for additional C1-INH administration after the self-administration of icatibant. The time from the onset of an acute attack to visiting ER for the additional treatment after the self-administration of icatibant significantly increased from 6.2 h to 19.2 h (p < 0.001). Icatibant, therefore, promoted the patients' behavior modification associated with ER visits for C1-INH administration during an acute attack of HAE-C1-INH.

Recombinant human C1 esterase inhibitor for hereditary angioedema attacks: A European registry

Background

Hereditary angioedema (HAE) due to C1 esterase inhibitor deficiency (C1-INH-HAE) is characterized by recurrent swelling attacks. A European treatment registry was established to review the adverse event profile and efficacy of recombinant human C1 esterase inhibitor (rhC1-INH) for HAE attacks.

Methods

Individuals with C1-INH-HAE were enrolled following a decision to treat with rhC1-INH and provision of written informed consent. Medical history and baseline HAE information were collected at screening. Healthcare providers entered data on HAE attacks, response to treatment, and adverse events using a web-based questionnaire.

Results

From July 1, 2011, through December 1, 2019, 71 patients with C1-INH-HAE (30 male/41 female; mean age, 47.3 years; age range, 19–78 years) in 9 countries reported 2356 attacks and were treated with rhC1-INH. Before registry entry, patients, including 20 (28.2%) who were on maintenance therapy/prophylaxis at registry enrollment, experienced a mean of 25 HAE attacks per year (median, 16 [range, 0–185]). Most treated HAE attacks were abdominal (46.1%), followed by peripheral (38.3%), oro-facial-pharyngeal (14.8%), urogenital (3.2%), and laryngeal (2.6%). The mean rhC1-INH dose was 3307 U (43.3 U/kg). Patients reported symptom improvement within 4 h for 97.8% of attacks (2305/2356) with rhC1-INH; most attacks (99.8%; 2351/2356) required only 1 dose. Five attacks were treated with a second dose (total rhC1-INH dose administered for attack, 4200 U). No hypersensitivity, thrombotic/thromboembolic events, or drug-related serious adverse events were reported.

Conclusion

The rhC1-INH treatment registry provided real-world data on the treatment of 2356 HAE attacks that were consistent with clinical trial data of rhC1-INH in patients with C1-INH-HAE.

Leveraging unstructured data to identify hereditary angioedema patients in electronic medical records

Background

The epidemiologic impact of hereditary angioedema (HAE) is difficult to quantify, due to misclassification in retrospective studies resulting from non-specific diagnostic coding. The aim of this study was to identify cohorts of patients with HAE-1/2 by evaluating structured and unstructured data in a US ambulatory electronic medical record (EMR) database.

Methods

A retrospective feasibility study was performed using the GE Centricity EMR Database (2006–2017). Patients with ≥ 1 diagnosis code for HAE-1/2 (International Classification of Diseases, Ninth Revision, Clinical Modification 277.6 or International Classification of Diseases, Tenth Revision, Clinical Modification D84.1) and/or ≥ 1 physician note regarding HAE-1/2 and ≥ 6 months’ data before and after the earliest code or note (index date) were included. Two mutually exclusive cohorts were created: probable HAE (≥ 2 codes or ≥ 2 notes on separate days) and suspected HAE (only 1 code or note). The impact of manually reviewing physician notes on cohort formation was assessed, and demographic and clinical characteristics of the 2 final cohorts were described.

Results

Initially, 1691 patients were identified: 190 and 1501 in the probable and suspected HAE cohorts, respectively. After physician note review, the confirmed HAE cohort comprised 254 patients and the suspected HAE cohort decreased to 1299 patients; 138 patients were determined not to have HAE and were excluded. The overall false-positive rate for the initial algorithms was 8.2%. Across final cohorts, the median age was 50 years and > 60% of patients were female. HAE-specific prescriptions were identified for 31% and 2% of the confirmed and suspected HAE cohorts, respectively.

Conclusions

Unstructured EMR data can provide valuable information for identifying patients with HAE-1/2. Further research is needed to develop algorithms for more representative HAE cohorts in retrospective studies.

Assessment and management of disease burden and quality of life in patients with hereditary angioedema: a consensus report

BACKGROUND

Hereditary angioedema (HAE) is a rare disease characterized by unpredictable, potentially life-threatening attacks, resulting in significant physical and emotional burdens for patients and families. To optimize care for patients with HAE, an individualized management plan should be considered in partnership with the physician, requiring comprehensive assessment of the patient's frequency and severity of attacks, disease burden, and therapeutic control. Although several guidelines and consensus papers have been published concerning the diagnosis and treatment of HAE, there has been limited specific clinical guidance on the assessment of disease burden and quality of life (QoL) in this patient population. Practical guidance is critical in supporting effective long-term clinical management of HAE and improving patient outcomes. The objective of this review is to provide evidence-based guidelines for an individualized assessment of disease burden and QoL in patients with HAE.

METHODS

A consensus meeting was held on February 29, 2020, consisting of 9 HAE experts from the United States and Europe with extensive clinical experience in the treatment of HAE. Consensus statements were developed based on a preliminary literature review and discussions from the consensus meeting.

RESULTS

Final statements reflect the consensus of the expert panel and include the assessment of attack severity, evaluation of disease burden, and long-term clinical management of HAE caused by C1-esterase inhibitor deficiency. Patient-reported outcome measures for assessing HAE attack severity and frequency are available and valuable tools; however, attack frequency and severity are insufficient markers of disease severity unless they are evaluated in the broader context of the effect on an individual patient's QoL. QoL assessments should be individualized for each patient and minimally, they should address the interference of HAE with work, school, social, family, and physical activity, along with access to and burden of HAE treatment. Advances in HAE therapies offer the opportunity for comprehensive, individualized treatment plans, allowing patients to achieve minimal attack burden with reduced disease and treatment burden.

CONCLUSION

This consensus report builds on existing guidelines by expanding the assessment of disease burden and QoL measures for patients with HAE.

Randomized Trial of the Efficacy and Safety of Berotralstat (BCX7353) as an Oral Prophylactic Therapy for Hereditary Angioedema: Results of APeX-2 Through 48 Weeks (Part 2)

BACKGROUND

Berotralstat (BCX7353) is a recently approved, oral, once-daily kallikrein inhibitor for hereditary angioedema (HAE) prophylaxis. In the APeX-2 trial, berotralstat reduced HAE attack rates over 24 weeks, with a favorable safety and tolerability profile.

OBJECTIVE

Evaluate berotralstat safety, tolerability, and effectiveness over 48 weeks.

METHODS

APeX-2 is a phase 3, parallel-group, multicenter trial (NCT03485911) in patients with HAE due to C1 esterase inhibitor deficiency. Part 1 was double-blind and placebo-controlled, with patients randomized to 24 weeks of berotralstat 150 mg, 110 mg, or placebo. In part 2, patients continued berotralstat the same dose or, if initially randomized to placebo, were rerandomized to berotralstat 150 mg or 110 mg through weeks 24 to 48. The primary end point was safety and tolerability.

RESULTS

One hundred eight patients received 1 or more doses of berotralstat in part 2. Treatment-emergent adverse events (TEAEs) occurred in 30 of 39 patients (77%) in the placebo group during part 1, and 25 of 34 patients (74%) re-randomized from placebo to berotralstat 110 mg or 150 mg in part 2, with drug-related TEAEs in 13 of 39 (33%), and 11 of 34 (32%) in the same groups. Most TEAEs were mild or moderate, with no serious drug-related TEAEs. The most common TEAEs were upper respiratory tract infections, abdominal pain, diarrhea, and vomiting. Mean (±standard error of the mean) monthly attack rates at baseline and week 48 were 3.06 (±0.25) and 1.06 (±0.25) in the berotralstat 150mg 48-week group and 2.97 (±0.21) and 1.35 (±0.33) in the berotralstat 110mg 48-week group.

CONCLUSIONS

The safety, tolerability, and effectiveness of berotralstat were maintained over 48 weeks of treatment.

Hereditary angioedema due to C1 inhibitor deficiency in Belarus: epidemiology, access to diagnosis and seven novel mutations in SERPING1 gene

Background

Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) is a rare disease. Few states in developing countries have an adequate management of HAE, but none of them belongs to the former USSR area. This study analyses data from C1-INH-HAE patients from Belarus.

Methods

Data about clinical characteristics, genetics, access to diagnosis and treatment were collected from 2010 by the Belarusian Research Center for Pediatric Oncology, Hematology and Immunology in Minsk. A questionnaire about attacks, prophylactic (LTP) and on-demand therapy (ODT) was administered to patients.

Results

We identified 64 C1-INH-HAE patients belonging to 26 families, 27 (42.2%) of which were diagnosed in the last 3 years. The estimated minimal prevalence was 1:148,000. Median age at diagnosis was 29 years, with diagnostic delay of 19 years. Thirty-eight patients answered a questionnaire about therapy. Eleven patients did not use any treatment to resolve HAE attacks. Twenty-seven patients underwent ODT: 9 with appropriate treatments, and 18 with inappropriate treatments. Nine patients used LTP with attenuated androgens and 1 with tranexamic acid. Thirty-two patients answered a questionnaire about attacks and triggers: 368 angioedema attacks were reported, with an average of 10 attacks per year. We found 24 different SERPING1 variants: 9 missenses, 6 in splice sites, 6 small deletions, 2 nonsense, 1 large deletion; 7 have not been previously described. De novo variants were found in 11 patients.

Conclusions

C1-INH-HAE diagnosis and management in Belarus is improved as seen from the high number of new diagnosis in the last 3 years. Next steps will be to reduce the diagnostic delay and to promote the LTP and ODT.

Recognition, Evaluation, and Management of Pediatric Hereditary Angioedema

ABSTRACT

Hereditary angioedema (HAE) is a rare, often underrecognized genetic disorder caused by either a C1 esterase inhibitor deficiency (type 1) or mutation (type 2). This leads to overproduction of bradykinin resulting in vasodilation, vascular leakage, and transient nonpitting angioedema occurring most frequently in the face, neck, upper airway, abdomen, and/or extremities. Involvement of the tongue and laryngopharynx has been associated with asphyxiation and death. Hereditary angioedema is an autosomal-dominant condition; therefore, there is a 50% chance an offspring will inherit this disorder. Any patient presenting with isolated angioedema should be screened with a C4 measurement, as 25% of cases have no family history of HAE. All patients with HAE will have a functional deficiency of C1 esterase inhibitor. Contributors that delay the diagnosis of HAE include recognition delay by clinicians who confuse this condition with histaminergic angioedema, the disease's varied presentations, and limitations to timely testing. Pediatric emergency clinicians should be knowledgeable about how to distinguish between bradykinin- and histamine-mediated angioedema, as there are significant differences in the diagnostic testing, treatment, and clinical response between these 2 different conditions. Evidence indicates that early diagnosis and treatment of HAE reduces morbidity and mortality. Clinician recognition of the mechanistically different problems will ensure patients are appropriately referred to an expert for outpatient management.

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

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

Recombinant Human C1 Esterase Inhibitor for the Management of Adverse Events Related to Intravenous Immunoglobulin Infusion in Patients With Common Variable Immunodeficiency or Polyneuropathy: A Pilot Open-Label Study

It has been hypothesized that low levels of C1 esterase inhibitor (C1-INH), a key inhibitor of the complement pathway, may play a role in the occurrence of adverse events (AEs) associated with intravenous immunoglobulin (IVIG) therapy. This open-label pilot study evaluated C1-INH replacement, with recombinant human C1-INH (rhC1-INH), as a potential therapy for adults requiring IVIG and experiencing AEs. Patients received two rounds of IVIG infusion [pre-treatment phase (no rhC1-INH), 4–8 weeks] and then three rounds of one dose of intravenous rhC1-INH 50 U/kg (maximum, 4,200 U) with subsequent IVIG infusion (treatment phase, 6–12 weeks). Nineteen adults completed the study; all had an autoimmune condition linked to common variable immunodeficiency (CVID) or polyneuropathy, and 57.9% had low baseline C1-INH levels. Mean ± SD total scores improved significantly with the Headache Impact Test (from 62.8 ± 6.2 at pre-treatment to 57.7 ± 9.1 after treatment; mean Δ, −5.0; p = 0.02) and Modified Fatigue Impact Scale (from 59.3 ± 13.1 to 51.2 ± 15.4; mean Δ, −8.1; p = 0.006). Significant improvements in the Migraine Disability Assessment were observed for three of five items (p ≤ 0.002). Mean ± SD C1-INH level increased from 26.8 ± 5.9 mg/dl after the second round of IVIG (pre-treatment) to 32.1 ± 7.8 mg/dl after the third rhC1-INH treatment; functional C1-INH levels increased from 115.8 ± 34.7% to 158.3 ± 46.8%. Future research is warranted to explore the benefit of C1-INH therapy for reduction of IVIG-related AEs, as well as the role of C1-INH in patients with CVID and autoimmune disease.

Recurrent and acute abdominal pain as the main clinical manifestation in patients with hereditary angioedema

Background: Hereditary angioedema (HAE) is a rare disease that often leads to misdiagnosis. The delay of diagnosis is > 10 years in China. Recurrent and acute abdominal pain is one of the common symptoms of HAE. Because of the high misdiagnosis rate, it usually results in unnecessary surgical procedures. This study focused on the clinical symptoms and management of HAE-related abdominal attacks in Chinese patients to provide some new insight for the emergency department (ED) physicians and gastroenterologists. Methods: A Web-based survey was conducted among 107 patients with HAE from 94 unrelated families. Detailed questions with respect to the abdominal attacks were asked, including the frequency, symptoms, and duration before and after confirmed diagnosis. The demographic characteristics, diagnosis process, and treatment outcomes were also included. Results: Approximately 70% of the patients with HAE presented with abdominal symptoms during the onset of edema, mostly characterized by pain (94.8%), nausea (83.1%), vomiting (83.1%), diarrhea (59.7%), and constipation (23.4%). The patients were easily misdiagnosed as having gastroenteritis (35.1%) and appendicitis (10.4%), and 24.7% of them received unnecessary appendectomy or laparotomy. Danazol, a widely used drug for long-term prophylaxis of HAE in China, can reduce the attack frequency and alleviate the abdominal symptoms, but the adverse effects are also significant and more severe in women. Conclusions: Abdominal symptoms are common and important clinical features of HAE but are easily confused with other gastrointestinal diseases. ED physicians and gastroenterologists should consider HAE when patients experience recurrent and unexplained abdominal pain. Proper medical treatment should be administered in a timely manner if an HAE diagnosis is confirmed and efforts are required to increase access in China to medications both for on-demand treatment and long-term prophylaxis.

Survey of actual conditions of erythema marginatum as a prodromal symptom in Japanese patients with hereditary angioedema

Background

Hereditary angioedema (HAE) is a rare but life-threatening condition. HAE types I and II (HAE-1/2) result from C1-inhibitor (C1–INH) deficiency. However, recent genetic analysis has established a new type of HAE with normal C1–INH (HAEnC1-INH). The mutations of factor XII, plasminogen, angiopoietin 1, and kininogen 1 genes may be the cause of HAEnC1-INH. Nevertheless, other causative molecules (HAE-unknown) may be involved. The Japanese therapeutic environment for HAE has been improving owing to the self-subcutaneous injection of icatibant, which was approved for the treatment of acute attack and enables early therapy. Erythema marginatum (EM) is a visible prodromal symptom which occasionally occurs prior to an angioedema attack; hence, recognizing the risk of an acute attack is important for early treatment. However, the detailed characteristics of EM remain unclear. In this study, we first investigated the clinical manifestations of EM in Japanese patients with HAE.

Methods

A 20-point survey was developed and distributed to 40 physicians to gather clinical data on EM from patients with HAE.

Results

Data on 68 patients with HAE (58 patients with HAE-1/2 and 10 patients with HAE-unknown) were collected. Of the patients with HAE-1/2, 53.4% experienced EM, whereas 43.1% did not. The forearm was the most frequent area of EM (64.5%), followed by the abdomen (29.0%) and upper arm and precordium (19.3%). Of the HAE-1/2 patients with EM, 41.9% always had angioedema following EM, while 29.0% always had colocalization of EM with angioedema. Moreover, 3.2% showed a correlation between the awareness of EM and severity of an angioedema attack. In 60.9% of HAE-1/2 patients with EM, the interval between the awareness of EM and appearance of angioedema was <3 h. Of the patients with HAE-unknown, 30.0% also experienced EM.

Conclusion

We confirmed that more than one-half of Japanese patients with HAE-1/2 and one-third of those with HAE-unknown develop EM as the prodromal symptom of an angioedema attack. Physicians should communicate the significance of EM to patients with HAE to prepare them for possible imminent attacks.

A case of hereditary angioedema due to C1-inhibitor deficiency with recurrent abdominal pain diagnosed 40 years after the occurrence of the initial symptom

Hereditary angioedema due to C1-inhibitor deficiency (HAE-C1-INH) is a rare disease, which induces an acute attack of angioedema mediated by bradykinin. HAE-C1-INH can cause serious abdominal pain when severe edema develops in the gastrointestinal tract. However, because it takes a long time, 13.8 years on average in Japan, from the occurrence of the initial symptom to the diagnosis due to low awareness of the disease, undiagnosed HAE-C1-INH patients sometimes undergo unnecessary surgical procedures for severe abdominal pain. We herein present a 56-year-old patient with HAE-C1-INH, who underwent numerous abdominal operations. He frequently needed hospitalization with the administration of opioid due to severe abdominal pain. However, after he was accurately diagnosed with HAE-C1-INH at 55 years of age, he could start self-administration for an acute attack with icatibant, a selective bradykinin B2 receptor antagonist. Consequently, he did not need hospitalizing for ten months after the beginning of the treatment. A series of an accurate diagnosis and appropriate treatment for HAE-C1-INH improved his quality of life. Thus, HAE-C1-INH should be considered, when we meet patients with unidentified recurrent abdominal pain. This case highlights significance of an early diagnosis and appropriate treatment for HAE-C1-INH.

Cut-off value of C1-inhibitor function for the diagnosis of hereditary angioedema due to C1-inhibitor deficiency

Hereditary angioedema caused by C1-inhibitor (C1-INH) deficiency (HAE-C1-INH) is a rare autosomal dominant disease. Primary care physicians sometimes face difficulties in diagnosing HAE-C1-INH owing to fluctuations in C1-INH function levels influenced by blood sampling conditions. International major guidelines do not stipulate a cut-off value of C1-INH function for the diagnosis. We aimed to explore the distribution of C1-INH function levels in patients with HAE-C1-INH and elucidate the influence of blood sampling conditions using healthy volunteers' samples to confirm the cut-off value of C1-INH function. In 48 patients with HAE-C1-INH who visited the Juntendo University Hospital in Japan between 2013 and 2019, C1-INH function levels were evaluated for 160 samples during symptom-free periods and 147 samples during an acute attack. Fluctuations of C1-INH function level were also evaluated for 8 healthy volunteers, wherein the samples were divided into 3 groups according to different sampling conditions. C1- INH function levels in all patients with HAE-C1-INH were found to be < 50%. The average C1- INH function level in healthy volunteers measured soon after blood collection in an appropriate sampling condition was 77% (61-92%) with some having lower C1-INH function levels than the reference value. C1-INH function levels fluctuated unstably in inappropriate sampling conditions. In conclusion, we can confirm that a < 50% C1-INH function level can be used as the diagnostic cut-off value for HAE-C1-INH. Moreover, it is necessary to repeat measurements of C1-INH function level in appropriate blood sampling conditions to accurately diagnose HAE-C1-INH.

Capillary leak syndrome and disseminated intravascular coagulation after kidney transplantation in a patient with hereditary angioedema - A case report

Background

Hereditary angioedema (HAE) is a rare disease caused by the deficiency of C1 esterase inhibitor. HAE has a risk of life-threatening complications such as capillary leak syndrome (CLS) and disseminated intravascular coagulation (DIC).

Case

A 42-year-old male patient with HAE presented for deceased-donor kidney transplantation. Prophylactic fresh frozen plasma (FFP) was given before surgery because of the risk of edema development. With careful management during anesthesia, there were no problems during surgery. However, generalized edema, hypotension, hypoalbuminemia, massive drainage of serosanguineous fluids from the intraabdominal space, and DIC occurred on the day after surgery. CLS was suspected and sustained hypotension with generalized edema became worse despite treatment with albumin, danazol, FFP, and vasoactive drugs. The patient’s condition worsened despite intensive care and he died due to shock.

Conclusions

The anesthesiologist should prepare for the critical complications of HAE and prepare the appropriate treatment options.

Current and Prospective Targets of Pharmacologic Treatment of Hereditary Angioedema Types 1 and 2

Hereditary angioedema (HAE) is a rare disease that causes episodic attacks of subcutaneous and submucosal edema, which can be painful, incapacitating, and potentially fatal. These attacks are mediated by excessive bradykinin production, as a result of uncontrolled activation of the plasma kallikrein/kinin system, which is caused by a C1 esterase inhibitor deficiency or dysfunction in HAE types 1 and 2, respectively. For many years, treatment options were limited to therapies with substantial adverse effects, insufficient efficacy, or difficult routes of administration. Increased insights in the pathophysiology of HAE have paved the way for the development of new therapies with fewer side effects. In the last two decades, several targeted novel therapeutic strategies for HAE have been developed, for both long-term prophylaxis and on demand treatment of acute attacks. This article reviews the advances in the development of more effective and convenient treatment options for HAE and their anticipated effects on morbidity, mortality, and quality of life. The emergence of these improved treatment options will presumably change current HAE guidelines, but adherence to these recommendations may become restricted by high treatment costs. It will therefore be essential to determine the indications and identify the patients that will benefit most from these newest treatment generations. Ultimately, current preclinical research into gene therapies may eventually lead the way towards curative treatment options for HAE. In conclusion, an increasing shift towards the use of highly effective long-term prophylaxis is anticipated, which should drastically abate the burden on patients with hereditary angioedema.

Recurrent angioedema in childhood: hereditary angioedema or histaminergic angioedema?

BACKGROUND

Recurrent angioedema is a rare entity during childhood. This study aimed to clarify differences between hereditary angioedema (HAE) and histaminergic angioedema (HA) in children.

METHODS

Fifty-seven children with HAE (male 36.8%, 8.9 years [5.4-12.5]) and 42 children with recurrent HA (male 42.9%, 11.5 years [8.1-16.8]) were analyzed.

RESULTS

The median age at symptom onset (6 [3-10]; 7.8 [4.5-13] years), frequency of angioedema episodes within last year (3 [2-5]; 5 [2-10]), and duration of symptoms (48 [24-48]; 24 [12-48] hours) were similar in the HAE and HA group, respectively. Recurrent urticaria was observed in 7.3% (n = 3) of patients in the HAE group and in 45.2% (n = 19) of the HA group (P < .001). While angioedema episodes involving the lips (n = 30; 71.4%; P = .035) and eyelids (n = 28; 66.7%; P = .012) were observed more frequently in the HA group, gastrointestinal involvement/abdominal pain (n = 15; 36.6%) was more common in HAE (P < .001). Itching as a prodromal symptom was detected in 47.6% (n = 20) of HA patients versus 14.6% (n = 6) of those with HAE (P = .002). In the logistic regression analysis for the diagnosis of HAE, a family history of angioedema (OR = 58.289 [95% CI 10.656-318.853], P < 001) and trauma (OR = 35.208 [95% CI [4.368-283.794]], P = .001) as a triggering factor were determined to be independent variables.

CONCLUSION

A family history of angioedema, trauma as a triggering factor, and abdominal pain should suggest the diagnosis of HAE and the need for further investigation.

Management of hereditary angioedema in Japan: Focus on icatibant for the treatment of acute attacks

Hereditary angioedema (HAE) is characterized by unpredictable, recurring and painful swelling episodes that can be disabling or even life-threatening. Awareness of HAE has progressively grown worldwide, and options for treatment of acute attacks and prevention of future attacks continue to expand; however, unmet needs in diagnosis and treatment remain. In Japan, recognition of HAE within the medical community remains low, and numerous obstacles complicate diagnosis and access to treatment. Importance of timely treatment of HAE attacks with on-demand therapies is continually demonstrated; recommended agents per the WAO/EAACI treatment guidelines published in 2018 include C1 inhibitor (C1-INH) concentrate, ecallantide, and icatibant. In Japan, multiple factors contribute to delayed HAE treatment (potentially leading to life-threatening consequences), including difficulties in finding facilities at which C1-INH agents are readily available. Recognition of challenges faced in Japan can help promote efforts to address current needs and expand access to effective therapies. Icatibant, a potent, selective bradykinin B₂ receptor antagonist, has demonstrated inhibition of various bradykinin-induced biological effects in preclinical studies and has shown efficacy in treating attacks in various clinical settings (e.g. clinical trials, real-world studies), and HAE patient populations (e.g. with C1-INH deficiency, normal C1-INH). Icatibant was approved in Japan for the treatment of HAE attacks in September 2018; its addition to the HAE treatment armamentarium contributes to improved patient care. In Japan, disease awareness and education campaigns are warranted to further advance the management of HAE patients in light of the unmet needs and the emerging availability of modern diagnostic approaches and therapies.

A robust multiplexed assay to quantify C1-inhibitor, C1q, and C4 proteins for in vitro diagnosis of hereditary angioedema from dried blood spot

Hereditary angioedema (HAE) is a rare genetic disease caused by deficiency or dysfunction of C1 esterase inhibitor (C1-INH). Plasma C1-INH activity and concentrations of C1-INH and complement components 1q and 4 (C1q, C4) are critical to the HAE diagnosis. We describe a novel multiplexed assay to simultaneously measure C1-INH, C1q, and C4 levels in dried blood spot (DBS) of HAE patients. The blood proteins were extracted from 3 mm punches of DBS samples and were subsequently digested by trypsin. The signature peptide derived from each protein was quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Analyte-depleted blood was generated as a surrogate matrix for the preparation of calibration curves to overcome the interference of endogenous proteins, and the assay reproducibility was further monitored by assessing the signal of plasma transferrin as a house-keeping protein. The assay was fully validated following regulatory guideline, with a quantification range of 12.5-800 μg/mL for C1-INH and C4 and 3.13-200 μg/mL for C1q. The precision and accuracy ranged from 3.3%-9.8% and -8.2%-12.6%, respectively. All the patient samples exhibited C1-INH levels lower than normal range except the Type II patient and the C4 and C1q concentrations were as expected. Results from the DBS-based LC-MS assay were highly correlated with the ELISA data measured in plasma of the same subjects. The method described here offers unique advantages such as less invasive sampling, minimal blood processing, and easy transportation and sample storage, allowing, for the first time, C1-INH, C4, and C1q levels to be simultaneously determined in a drop of dried blood.

Hereditary angioedema: On-demand treatment of angioedema attacks

The availability of effective acute treatment for angioedema has been fundamental in reducing the burden of illness for patients with hereditary angioedema (HAE). In building on the foundation of scientific advances that elucidate the pathomechanism(s) of attacks related to vascular permeability, novel targeted on-demand treatments have been developed and approved. These therapies have provided the means to arrest episodes of swelling, which, in the past, had the potential to inexorably lead to morbidity, and even mortality, for patients with HAE. Access to these medications, along with an emphasis on early administration and guidance that all attacks are candidates for treatment, has shifted the management paradigm for HAE. Although unmet needs remain, these acute therapies, coupled with advances in prophylactic treatment, have furthered the goal for all patients with HAE to live a normal life.

The Immunopathology of Complement Proteins and Innate Immunity in Autoimmune Disease

The complement is a powerful cascade of the innate immunity and also acts as a bridge between innate and acquired immune defence. Complement activation can occur via three distinct pathways, the classical, alternative and lectin pathways, each resulting in the common terminal pathway. Complement activation results in the release of a range of biologically active molecules that significantly contribute to immune surveillance and tissue homeostasis. Several soluble and membrane-bound regulatory proteins restrict complement activation in order to prevent complement-mediated autologous damage, consumption and exacerbated inflammation. The crucial role of complement in the host homeostasis is illustrated by association of both complement deficiency and overactivation with severe and life-threatening diseases. Autoantibodies targeting complement components have been described to alter expression and/or function of target protein resulting in a dysregulation of the delicate equilibrium between activation and inhibition of complement. The spectrum of diseases associated with complement autoantibodies depends on which complement protein and activation pathway are targeted, ranging from autoimmune disorders to kidney and vascular diseases. Nevertheless, these autoantibodies have been identified as differential biomarkers for diagnosis or follow-up of disease only in a small number of clinical conditions. For some autoantibodies, a clear relationship with clinical manifestations has been identified, such as anti-C1q, anti-Factor H, anti-C1 Inhibitor antibodies and C3 nephritic factor. For other autoantibodies, the origin and the functional consequences still remain to be elucidated, questioning about the pathophysiological significance of these autoantibodies, such as anti-mannose binding lectin, anti-Factor I, anti-Factor B and anti-C3b antibodies. The detection of autoantibodies targeting complement components is performed in specialized laboratories; however, there is no consensus on detection methods and standardization of the assays is a real challenge. This review summarizes the current panorama of autoantibodies targeting complement recognition proteins of the classical and lectin pathways, associated proteases, convertases, regulators and terminal components, with an emphasis on autoantibodies clearly involved in clinical conditions.

Current medical management of hereditary angioedema: Follow-up survey of US physicians

BACKGROUND

Physician surveys on hereditary angioedema (HAE) management in 2010 and 2013 revealed important trends in HAE care.

OBJECTIVE

To evaluate current HAE management and the impact of new treatment options on physician practice patterns over time.

METHODS

During June and July 2019, 5382 physicians were contacted by means of postal mail to complete a 47-question survey; 177 responded (3%).

RESULTS

Across the 3 surveys, the home replaced the emergency department as the most typically reported setting for HAE attack treatment (54.3% vs 11.6% in 2010 and 32.5% in 2013; P < .001). Physicians reported C1 esterase inhibitor (C1-INH) as the most typically prescribed long-term prophylactic treatment (LTP) (60.0% vs 20.4% in 2010 and 56.7% in 2013; P < .001). Subcutaneous LTP medications were most typically prescribed over intravenous (C1-INH, 41.4%; subcutaneous lanadelumab, 21%; intravenous C1-INH, 18.6%). Danazol, the most frequently prescribed LTP treatment, dropped to 6.4% (55.8% in 2010 and 23.4% in 2013; P < .001). The strongest nonefficacy factor influencing clinician treatment choice changed over time, with cost and (or) insurance coverage increasing to 43.7% (from 24.4% in 2010 and 40.5% in 2013; P = .001), whereas the concern over adverse effects dropped to 16.2% (from 55.8% in 2010 and 29.5% in 2013; P < .001). Physician-reported patient satisfaction remains high, with only 1.5% of physicians indicating patients are not satisfied with treatment.

CONCLUSION

The US physician survey data reflect improvements in the HAE management in recent years. Therapeutic advances in HAE have led to reported higher rates of home treatment of HAE attacks, reduced concern for adverse treatment effects, and high levels of patient satisfaction.

Oral once-daily berotralstat for the prevention of hereditary angioedema attacks: A randomized, double-blind, placebo-controlled phase 3 trial

BACKGROUND

Berotralstat (BCX7353) is an oral, once-daily inhibitor of plasma kallikrein in development for the prophylaxis of hereditary angioedema (HAE) attacks.

OBJECTIVE

Our aim was to determine the efficacy, safety, and tolerability of berotralstat in patients with HAE over a 24-week treatment period (the phase 3 APeX-2 trial).

METHODS

APeX-2 was a double-blind, parallel-group study that randomized patients at 40 sites in 11 countries 1:1:1 to receive once-daily berotralstat in a dose of 110 mg or 150 mg or placebo (Clinicaltrials.gov identifier NCT03485911). Patients aged 12 years or older with HAE due to C1 inhibitor deficiency and at least 2 investigator-confirmed HAE attacks in the first 56 days of a prospective run-in period were eligible. The primary efficacy end point was the rate of investigator-confirmed HAE attacks during the 24-week treatment period.

RESULTS

A total of 121 patients were randomized; 120 of them received at least 1 dose of the study drug (n = 41, 40, and 39 in the 110-mg dose of berotralstat, 150-mg of dose berotralstat, and placebo groups, respectively). Berotralstat demonstrated a significant reduction in attack rate at both 110 mg (1.65 attacks per month; P = .024) and 150 mg (1.31 attacks per month; P < .001) relative to placebo (2.35 attacks per month). The most frequent treatment-emergent adverse events that occurred more with berotralstat than with placebo were abdominal pain, vomiting, diarrhea, and back pain. No drug-related serious treatment-emergent adverse events occurred.

CONCLUSION

Both the 110-mg and 150-mg doses of berotralstat reduced HAE attack rates compared with placebo and were safe and generally well tolerated. The most favorable benefit-to-risk profile was observed at a dose of 150 mg per day.

Tranexamic acid for ACE inhibitor induced angioedema - A case report

Tranexamic acid (TXA) is an antifibrinolytic agent which inhibits conversion of plasminogen to plasmin, a key step in kallikrein activation and bradykinin formation. Tranexamic acid is used in prophylactic management of hereditary angioedema; however, evidence for TXA in angiotensin converting enzyme (ACE) inhibitor-induced angioedema (ACEI-AE) is limited. We describe a patient who presented to the emergency department with ACEI-AE who was successfully treated with TXA. This case suggests that TXA may be a beneficial treatment modality in the management of ACEI-AE and warrants further investigation.

Antisense Inhibition of Prekallikrein to Control Hereditary Angioedema

Hereditary angioedema is characterized by recurrent and unpredictable episodes of subcutaneous and mucosal swelling that can be life threatening. IONIS-PKK-L_Rx is a ligand-conjugated antisense oligonucleotide designed for receptor-mediated delivery to hepatocytes. In a compassionate-use pilot study, two patients with severe bradykinin-mediated angioedema were initially administered weekly subcutaneous injections of the unconjugated parent drug, IONIS-PKK_Rx, for 12 to 16 weeks, after which they received IONIS-PKK-L_Rx at a dose of 80 mg every 3 to 4 weeks for 7 to 8 months. Treatment was accompanied by a reduction in the angioedema attack rate. (Funded by Amsterdam UMC.).

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.

Long-Term Efficacy of Subcutaneous C1 Inhibitor in Pediatric Patients with Hereditary Angioedema

Background: Hereditary angioedema (HAE) due to C1 inhibitor (C1INH) deficiency is characterized by recurrent attacks of edema of the skin and mucosal tissues. Symptoms usually present during childhood (mean age at first attack, 10 years). Earlier symptom onset may predict a more severe disease course. Subcutaneous (SC) C1INH is indicated for routine prophylaxis to prevent HAE attacks in adolescents and adults. We analyzed the long-term efficacy of C1INH (SC) in subjects ≤17 years old treated in an open-label extension (OLE) of the pivotal phase III Clinical Study for Optimal Management of Preventing Angioedema with Low-Volume Subcutaneous C1 Inhibitor Replacement Therapy (COMPACT) trial.

Methods: Eligible subjects (age ≥6 years, with ≥4 attacks over 2 consecutive months before entry into the OLE or placebo-controlled COMPACT trial) were treated with C1INH (SC) 40 or 60 IU/kg twice weekly for 52–140 weeks. Subgroup analyses by age (≤17 vs. >17 years) were performed for key efficacy endpoints.

Results: Ten subjects were ≤17 years old [mean (range) age, 13.3 (8–16) years, 3 subjects <12 years old; exposure range, 51–133 weeks]. All 10 pediatric subjects experienced ≥50% reduction (mean, 93%) in number of attacks versus the prestudy period, with a 97% reduction in the median number of attacks/month (0.11). All subjects had <1 attack/4-week period and 4 had <1 attack/year (1 subject was attack free). No subject discontinued treatment due to a treatment-related adverse event.

Conclusions: Data from pediatric subjects treated with C1INH (SC) for up to 2.55 years and adult subjects revealed similar efficacy. C1INH (SC) is effective and well tolerated as long-term prophylaxis in children, adolescents, and adults with HAE.

US HAEA Medical Advisory Board 2020 Guidelines for the Management of Hereditary Angioedema

Scientific and clinical progress together with the development of effective novel therapeutic options has engendered multiple important changes in the diagnosis and management of hereditary angioedema (HAE). We now update and extend the 2013 United States Hereditary Angioedema Association Medical Advisory Board guidelines for the treatment and management of HAE. The guidelines are based on a comprehensive literature review with recommendations indicating both the strength of our recommendation and the quality of the underlying evidence. Guidelines are provided regarding the classification, diagnosis, on-demand treatment, prophylactic treatment, special considerations for women and children, development of a comprehensive management and monitoring plan, and assessment of burden of illness for both HAE due to C1 inhibitor deficiency and HAE with normal C1 inhibitor. Advances in HAE treatment now allow the development of management plans that can help many patients with HAE lead a normal life. Achieving this goal requires that physicians be familiar with the diagnostic and therapeutic transformations that have occurred in recent years.

A Germany-wide survey study on the patient journey of patients with hereditary angioedema

Background

Hereditary angioedema (HAE) is a rare genetic disease and characterized by clinical features such as paroxysmal, recurrent angioedema of the skin, the gastrointestinal tract, and the upper airways. Swelling of the skin occurs primarily in the face, extremities and genitals. Gastrointestinal attacks are accompanied by painful abdominal cramps, vomiting and diarrhea. Due to the low prevalence and the fact that HAE patients often present with rather unspecific symptoms such as abdominal cramps, the final diagnosis is often made after a long delay. The aim of this German-wide survey was to characterize the period between occurrence of first symptoms and final diagnosis regarding self-perceived health, symptom burden and false diagnoses for patients with HAE.

Results

Overall, 81 patients with HAE were included and participated in the telephone-based survey. Of those, the majority reported their current health status as “good” (47.5%) or “very good” (13.8%), which was observed to be a clear improvement compared to the year before final diagnosis (“good” (16.3%), “very good” (11.3%)). Edema in the extremities (85.2%) and in the gastrointestinal tract (81.5%) were the most currently reported symptoms and occurred earlier than other reported symptoms (mean age at onset 18.1 and 17.8 years, respectively). Misdiagnoses were observed in 50.6% of participating HAE patients with appendicitis and allergy being the most frequently reported misdiagnoses (40.0 and 30.0% of those with misdiagnosis, respectively). Patients with misdiagnosis often received mistreatment (80.0%) with pharmaceuticals and surgical interventions as the most frequently carried out mistreatments (65.6 and 56.3% of those with mistreatment, respectively). The mean observed diagnostic delay was 18.1 years (median 15.0 years). The diagnostic delay was higher in older patients and index patients.

Conclusions

This study showed that self-perceived status of health for patients is much better once the final correct diagnosis has been made and specific treatment was available. Further challenge in the future will still be to increase awareness for HAE especially in settings which are normally approached by patients at occurrence of first symptoms to assure early referral to specialists and therefore increase the likelihood of receiving an early diagnosis.