Clinical manifestations, diagnosis, and treatment of hereditary angioedema: survey data from 94 physicians in Japan

Health-related quality of life in patients with inborn errors of immunity: A systematic review and meta-analysis

BACKGROUND

Inborn Errors of Immunity (IEI) significantly affect patients' health-related quality of life (HRQOL), presenting greater challenges than those faced by the healthy population and other chronic disease sufferers. Current research lacks comprehensive integration of this critical issue.

OBJECTIVE

This study explores HRQOL in IEI patients, identifies impacting factors, and advocates for increased research focus on their quality of life.

METHODS

Following systematic review and meta-analysis guidelines, a search of Scopus and PubMed until November 15, 2023, yielded 1633 publications. We evaluated the literature, assessed study quality, and compared the HRQOL of IEI patients to that of healthy individuals and other chronic disease patients.

RESULTS

Of 90 articles and 10,971 IEI patients analyzed, study quality varied (nine good, 63 moderate, and 18 poor). The Short Form-36 (SF-36) and Pediatric Quality of Life Inventory generic core scales (PedsQL) were the primary generic instruments used among adults and children, respectively, with 12 studies each using the disease-specific instruments. Meta-analysis showed IEI patients have significantly lower scores in general health, physical and mental health, and social and emotional roles compared to healthy populations. We noted significant differences between self and proxy reports, indicating caregiver anxiety and perception disparities.

CONCLUSION

Despite limitations like small sample sizes and reliance on generic instruments, this research underscores the substantially lower HRQOL among IEI patients, emphasizing the need for a patient-centered, multidisciplinary approach to improve their life quality and calling for more focused attention on IEI patients and their caregivers' HRQOL.

Epidemiology, economic, and humanistic burden of hereditary angioedema: a systematic review

BACKGROUND

This systematic study aims to assess the global epidemiologic, economic, and humanistic burden of illness associated with all types of hereditary angioedema.

METHODS

A systematic search for articles reporting the epidemiologic, economic, and humanistic burden associated with patients with HAE was conducted using English and Chinese literature databases from the inception to May 23, 2022. The selected studies were assessed for their quality and risk of bias. The study was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses and registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD42022352377).

RESULTS

In total, 65 articles that met the search inclusion criteria reported 10,310 patients with HAE, of whom 5861 were female patients. Altogether, 4312 patients (81%) and 479 patients (9%) had type 1 and type 2 HAE, respectively, whereas 422 patients (8%) had HAE-normal C1-INH. The overall prevalence of all types of HAE was between 0.13 and 1.6 cases per 100,000. The mean or median delay from the first onset of a symptom of HAE to confirmed diagnosis ranged from 3.9 to 26 years. The estimated risk of death from asphyxiation was 8.6% for patients with HAE. Hospitalization, medication, unnecessary surgeries, doctor visits, specialist services, and nursing costs are direct expenses that contribute to the growing economic burden. The indirect cost accounted mostly due to missing work ($3402/year) and loss of productivity ($5750/year). Furthermore, impairment of QoL as reported by patient-reported outcomes was observed. QoL measures identified depression, anxiety, and stress to be the most common symptoms for adult patients and children.

CONCLUSION

This study highlights the importance of early diagnosis and the need for improving awareness among health care professionals to reduce the burden of HAE on patients and society.

Multidisciplinary Prophylactic Strategies for Recurrence of Laryngeal Edema After Tooth Extraction in a Patient With Hereditary Angioedema: A Case Report

Hereditary angioedema (HAE), caused by C1-inhibitor (C1-INH) deficiency or dysfunction, is a rare and potentially life-threatening disease that leads to unpredictable recurrent attacks of angioedema in localized regions, including the larynx. As medical or dental procedures can trigger laryngeal edema, resulting in asphyxiation, major global guidelines recommend short-term prophylaxis prior to invasive procedures and long-term prophylaxis to prevent acute attacks and achieve near-normal lives. Here, we report the case of a 63-year-old male who experienced asphyxiation after tooth extraction. Emergency tracheotomy had saved his life at the age of 40 years, before the diagnosis of HAE. At the age of 63, when he had another opportunity for tooth extraction, he was definitively diagnosed with HAE. Administering short-term prophylaxis with ongoing long-term prophylaxis for HAE and perioperative multidisciplinary management for tooth extraction helped prevent recurrent fatal angioedema due to dental procedures and this can be useful when managing patients with HAE.

Hereditary angioedema with an acute attack resolved after bone marrow transplantation for acute myeloid leukemia: a case report

BACKGROUND

Hereditary angioedema (HAE), which is caused by C1-inhibitor (C1-INH) deficiency or dysfunction, is a rare and potentially life-threatening disease. In patients with HAE, excess production of bradykinin causes acute unpredictable recurrent attacks of angioedema in localized regions, including the larynx and intestines. Given the fact that HAE is an autosomal dominant disease, C1-INH produced in patients with HAE is 50% of that produced in healthy individuals. However, most patients with HAE present plasma C1-INH function of < 25% owing to the chronic consumption of C1-INH by kallikrein-kinin, contact, complement, coagulation, and fibrinolysis cascades. Recently, several therapeutic options have been developed for acute attacks and prophylaxis in the treatment of HAE; however, currently, there is no curative therapy for HAE.

CASE PRESENTATION

Here we report the case of a 48-year-old male patient who presented with a long-standing history of HAE and underwent bone marrow transplantation (BMT) for acute myeloid leukemia (AML) at the age of 39 years and has been in complete remission of AML and HAE thereafter. Notably, after BMT, his C1-INH function gradually increased as follows: < 25%, 29%, 37%, and 45.6%. Since his 20 s, he intermittently presented with an acute attack of HAE once every 3 months from the initial attack. Further, after undergoing BMT, the number of acute attacks decreased to twice within 4 years until the age of 45 years, and subsequently, the patient has been free of acute attacks. C1-INH is mainly synthesized by hepatocytes, but it is known to be partially produced and secreted from peripheral blood monocytes, macrophages, endothelial cells, and fibroblasts. We speculate that the C1-INH function may be increased by extrahepatic production of C1-INH, possibly synthesized by differentiated cells derived from hematopoietic and mesenchymal stem cells after BMT.

CONCLUSIONS

This case report supports efforts to focus on extrahepatic production of C1-INH in the next strategy of new treatment development for HAE.

A narrative review of recent literature of the quality of life in hereditary angioedema patients

Hereditary angioedema (HAE) is a rare disorder that causes unpredictable and debilitating cutaneous and submucosal edema and can lead to death. HAE can impair patients' ability to perform daily activities, proportional to pain severity, with patients reporting lower productivity, missed time from work or school and potentially resulting in missed career and educational opportunities. Many patients with HAE experience a significant psychological burden, including anxiety and depression. Available treatment aims to prevent and/or treat HAE attacks as they occur, to reduce morbidity and mortality and, finally, to improve health-related quality of life. Two different validated specific angioedema instruments are available to assess patients' quality of life. The Angioedema Quality of Life Questionnaire (AE-QoL) examines diagnosed patients' quality of life but is not specific for HAE. The disease-specific questionnaire is the Hereditary Angioedema Quality of Life (HAE-QoL), and the first used for hereditary angioedema with C1 inhibitors (C1-INH) deficiency. These quality-of-life instruments are helpful to the HAE patients' assessment and to the development of better therapeutic strategies as clinical tools, as defined by international guidelines. Considering this context, this review was conducted to compare the effects of acute vs. long-term prophylaxis on HAE patients' health-related quality of life. In addition, the prevalence of anxiety and depression among these individuals was also reviewed.

Why does it take so long for rare disease patients to get an accurate diagnosis?—A qualitative investigation of patient experiences of hereditary angioedema

Introduction

Many patients with rare diseases experience a diagnostic delay. Although several quantitative studies have been reported, few studies have used a qualitative approach to directly examine how patients with rare disease obtain a diagnosis and why it takes many years. In this study, we focused on hereditary angioedema (HAE), which has been reported to have long diagnostic delays, despite the knowledge that not having an accurate diagnosis can cause life-threatening problems.

Objective

The objective of this study was to analyze patients’ experiences and elucidate why it takes a long time to reach a diagnosis of HAE. We also aimed to propose possible solutions for the problem.

Methods

A qualitative study using semi-structured interviews was conducted. Nine patients who took over 5 years from the presentation of initial symptoms to an HAE diagnosis participated. The contents of the interviews were subjected to an inductive contents analysis.

Results

By analyzing the patients’ struggles that were experienced during the undiagnosed period, three themes were generated: (1) acceptance and resignation towards their conditions, (2) proactive search for a cause, and (3) independent efforts outside of the hospital. While a few patients continued to seek out a diagnosis during the undiagnosed period, many had become accustomed to their health condition without suspecting a rare disease.

Conclusions

We found that one of the most important factors related to the prolonged undiagnosed period is the lack of suspicion of a rare disease by patients and their medical professionals. While current policies tend to focus on the period from suspecting rare diseases to the time of a clear diagnosis, our results strongly suggest that measures are needed to facilitate patients and clinicians to become aware of rare diseases.

Clinical Characteristics and Management of Angioedema Attacks in Polish Adult Patients with Hereditary Angioedema Due to C1-Inhibitor Deficiency

Hereditary angioedema (HAE) due to C1-inhibitor (C1-INH) deficiency is a rare disease characterized by recurrent swellings. This study aims to determine (i) the clinical characteristics of the HAE patient population from Poland, and (ii) real-life patients' treatment practices. A cross-sectional study involved 138 adult HAE patients (88 females, 50 males) treated in six regional HAE centers in Poland. Consecutive patients during routine follow-up visits underwent a structured medical interview on the clinical characteristics of the course and treatment of HAE attacks within the last six months. A total of 118 of 138 patients was symptomatic. They reported in total 2835 HAE attacks predominantly peripheral and abdominal, treated with plasma-derived C1-INH (61.4%), icatibant (36.7%) and recombinant C1-INH (1.9%). An amount of 116 patients carried the rescue medication with them while traveling, and 74 patients self-administrated on demand treatment. There were twice as many symptomatic women (n = 78) as there were men (n = 40). Women treated their HAE attacks significantly more often than men. Older patients (≥65 years) reported a longer delay in diagnosis, and practiced the self-administration of rescue medication less frequently in comparison to other patients. Clinical features of the surveyed population are similar to other European, but not Asian, HAE patient groups. Self-administration still remains an unmet medical need. Some distinct HAE patients may require special attention due to the severe course of the disease (females) or a delay in diagnosis (the elderly).

Oral berotralstat for the prophylaxis of hereditary angioedema attacks in patients in Japan: A phase 3 randomized trial

Background

With no approved treatments in Japan for the prevention of hereditary angioedema (HAE) attacks, there is a significant unmet need for long‐term prophylactic therapies for Japanese patients with HAE. Berotralstat (BCX7353) is an oral, once‐daily, highly selective inhibitor of plasma kallikrein in development for prophylaxis of angioedema attacks in HAE patients.

Methods

APeX‐J is a phase 3, randomized, double‐blind, placebo‐controlled, parallel‐group, 3‐part trial conducted in Japan (University Hospital Medical Information Network identifier, UMIN000034869; ClinicalTrials.gov identifier, NCT03873116). Patients with a clinical diagnosis of type 1 or 2 HAE underwent a prospective run‐in period of 56 days to determine eligibility, allowing enrollment of those with ≥2 expert‐confirmed angioedema attacks. Patients were randomly assigned (1:1:1) and stratified by baseline attack rate (≥2 vs. <2 expert‐confirmed attacks/month between screening and randomization) to receive once‐daily berotralstat 110 mg, berotralstat 150 mg, or placebo. The primary endpoint was the rate of expert‐confirmed angioedema attacks during dosing in the 24‐week treatment period.

Results

Nineteen patients were randomized to receive once‐daily berotralstat 110 mg (n = 6), berotralstat 150 mg (n = 7), or placebo (n = 6). Treatment with berotralstat 150 mg significantly reduced HAE attacks relative to placebo (1.11 vs. 2.18 attacks/month, p = .003). The most frequently reported treatment‐emergent adverse events (TEAEs) in berotralstat‐treated patients (n = 13) were nasopharyngitis (n = 4, 31%), abdominal pain, cough, diarrhea, and pyrexia (n = 2 each, 15%).

Conclusions

Orally administered, once‐daily berotralstat 150 mg significantly reduced the frequency of HAE attacks and was safe and well tolerated, supporting its use as a prophylactic therapy in patients with type 1 or 2 HAE in Japan.

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.

The diagnosis and treatment of hereditary angioedema patients in Japan: A patient reported outcome survey

BACKGROUND

The rate at which patients are accurately diagnosed with hereditary angioedema (HAE), as well as diagnosed patients access to modern treatments differs greatly among countries. Moreover, the severity and burden of HAE on patients have been reported mostly on the basis of physician-reported surveys. To gain insight into the real-world conditions of patients with HAE through a patient-reported survey in Japan and identify any unmet needs.

METHODS

A questionnaire was distributed to 121 patients with HAE via a Japanese HAE patient organization during 2016-2017. Responses were collected from 70 patients (57.9%) and subjected to analysis.

RESULTS

The average periods from the initial appearance of symptoms (e.g. edema) to a HAE diagnosis was 15.6 years (min-max, 0-53). Patients visited an average of 4.6 different departments until receiving a definitive diagnosis. The average age at the first visit was 25.6 years (3-73) and at diagnosis 32.8 years (0-73). Patients reported an average of 15.7 (0-100) attacks per year, but only 53.1% of attacks were treated. The days of hospitalization due to severe attacks was 14.3 (0-200) before diagnosis, but these declined to 4.3 (0-50) after diagnosis. In the treatment for attacks, 82% of the patients were treated with the plasma-derived C1 inhibitor concentrate, and 69% of the patients reported experiencing a therapeutic effect.

CONCLUSIONS

There is a long gap between first attack and diagnosis of HAE, and the number of non-treated attacks is high in Japan. Steps are needed to improve the diagnostic and treatment environments to address these issues.

Novel SERPING1 gene mutations and clinical experience of type 1 hereditary angioedema from North India

BACKGROUND

There is paucity of literature on long-term follow-up of patients with hereditary angioedema (HAE) from developing countries.

OBJECTIVE

This study was carried out to analyze the clinical manifestations, laboratory features, and genetic profile of 32 patients (21 male and 11 female) from 23 families diagnosed with HAE between January 1996 and December 2019.

METHODS

Data were retrieved from medical records of Paediatric Immunodeficiency Clinic, Postgraduate Institute of Medical Education and Research, Chandigarh, India.

RESULTS

Median age at onset of symptoms was 6.25 years (range 1-25 years), and median age at diagnosis was 12 years (range 2-43 years). Serum complement C4 level was decreased in all patients. All patients had low C1-esterase inhibitor (C1-INH) quantitative level (type 1 HAE). SERPING1 gene sequencing could be carried out in 20 families. Of these, 11 were identified to have a pathogenic disease-causing variant in the SERPING1 gene. While 2 of these families had a previously reported mutation, remaining 9 families had novel pathogenic variants in SERPING1 gene. Because of non-availability of C1-INH therapy in India, all patients were given long-term prophylaxis (attenuated androgens or tranexamic acid (TA) or a combination of the 2). Life-threatening episodes of laryngeal edema were managed with fresh-frozen plasma (FPP) infusions. We recorded one disease-related mortality in our cohort. This happened in spite of long-term prophylaxis with stanozolol and TA.

CONCLUSIONS

We report largest single-center cohort of patients with HAE from India. Attenuated androgens, fibrinolytic agents, and FPP may be used for management of HAE in resource-limited settings.

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.

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.

Efficacy, pharmacokinetics, and safety of icatibant for the treatment of Japanese patients with an acute attack of hereditary angioedema: A phase 3 open-label study

BACKGROUND

Hereditary angioedema (HAE) is a genetic disease characterized by recurrent swelling episodes affecting the skin, gastrointestinal mucosa, and upper respiratory tract.

METHODS

A phase 3, single-arm, open-label study was performed to evaluate a selective bradykinin B₂ receptor antagonist, icatibant, for the treatment of acute attacks in Japanese patients with HAE Type I or II. After the onset of an acute attack, icatibant 30 mg was administered by the patient or a healthcare professional via subcutaneous injection in the abdomen.

RESULTS

Eight patients who had an attack affecting the skin (n = 4), abdomen (n = 3), or larynx (n = 1) were treated with icatibant (3 of the injections were self-administered). The median time to onset of symptom relief was 1.75 h (95% confidence interval, 1.00-2.50), and all patients had symptom relief within 5 h after administration. The time to maximum plasma concentration of icatibant was 1.79 h, and the maximum plasma concentration was 405 ng/ml. Seven patients experienced an injection site reaction, and 3 patients had adverse events (2 patients had a worsening or repeat HAE attack 29.0 and 18.3 h after icatibant administration, respectively, and 1 had headache).

CONCLUSIONS

Although the number of patients is small, the efficacy and tolerability of icatibant for acute attacks were demonstrated in Japanese patients with HAE, regardless of self-administration or administration by healthcare professional.

Suffocation due to Acute Airway Edema in a Patient with Hereditary Angioedema Highlighted the Need for Urgent Improvements in Treatment Availability in Japan

A 42-year-old Japanese man with hereditary angioedema suffered accidental trauma to his jaw in Shizuoka Prefecture, Japan, which gradually caused facial edema. Since plasma-derived human C1 inhibitor (pdh C1-INH) was unavailable, he had to be transferred to Juntendo University Hospital in Tokyo. Due to his severe edema, he suffered asphyxiation leading to cardiopulmonary arrest upon arrival. The patient was resuscitated and promptly treated with pdh C1-INH. In Japan, the self-administration of pdh C1-INH is not allowed, and every prefecture does not always possess stocks of pdh C1-INH. This case emphasizes the need for urgent improvements in treatment availability in Japan.

Hereditary angioedema from the patient's perspective: A follow-up patient survey

BACKGROUND

We conducted our first patient survey at the 2013 hereditary angioedema (HAE) patient summit and learned that, despite several novel therapies, the burden of disease was high.

OBJECTIVE

To determine, from the patient's perspective, if any improvements in the current state of HAE care occurred over a two-year period between HAE patient summits.

METHODS

A patient survey was conducted at the 2015 Hereditary Angioedema Association conference by using paper surveys that aimed at understanding the current state of HAE care. Questions included patient characteristics, burden of disease, and satisfaction with care and treatment options. Comparisons between patients with HAE with C1-inhibitor (HAE-C1INH) and patients with HAE with normal C1-inhibitor (HAE-nlC1INH), as well as between patients with HAE in 2013 and 2015, were performed by using χ2 tests.

RESULTS

There were 232 surveys distributed, and 143 surveys were identified as complete for inclusion and analysis from patients with self-reported HAE. Most patients had type I or type II HAE (67.5% [n = 106]), with a smaller number of patients with HAE-nlC1INH (23.6% [n = 37]). In 2015, almost half of the patients with HAE-C1INH (47.1%) and 56.7% of the patients with HAE-nlC1INH experienced a delay of ≥10 years between initial symptoms and diagnosis. Among the patients with HAE-C1INH, 25% reported one or more attacks per week and another 48% reported experiencing one or more attacks per month (fewer than one attack per week). The patients with HAE-nlC1INH reported attacks more frequently than did the patients with HAE-C1INH (p = 0.002), with 59.5% who reported attacks at least once a week. Emergency care was reported one or more times per month in 5% of the patients with HAE-C1INH and in 24.3% of the patients with HAE-nlC1INH.

CONCLUSION

Similar to 2013, although significant progress has been made, there is still a high burden of disease that faces patients with HAE.

Clinical Features of Hereditary Angioedema in Korean Patients: A Nationwide Multicenter Study

BACKGROUND

Hereditary angioedema (HAE) is a genetically heterogeneous autosomal dominant disorder characterized by recurrent episodes of nonpruritic, nonpitting edema increasing after puberty. It can be fatal due to laryngeal or gastrointestinal (GI) involvement with varied and changing frequency of mortality according to studies published from the Western countries. Epidemiological and clinical data of HAE in Asian countries are sparse. We sought to examine the clinical characteristics of HAE patients in Korea.

METHODS

Patients diagnosed with HAE at 15 tertiary hospitals across the country until 2016 were retrospectively reviewed.

RESULTS

A total of 65 patients diagnosed with HAE by 2016 were identified. The prevalence of HAE was estimated at 1.3/1,000,000 in Korea. Of the 65 patients, 21 (32.3%) were males. A total of 90.8% patients had type I HAE, while the remaining 9.2% patients had type II HAE. The first symptom developed after 20 years in 73.8% of patients, with a mean age 28.4 ± 14.1 years. The age at diagnosis was 36.5 ± 15.8 years, with a mean time delay of 7.8 ± 10.5 years. While the face (82.3%) and extremities (upper 71.0%, lower 62.9%) were the most frequently involved, the GI tract was affected in 40.5% of Korean HAE patients. Prophylaxis was maintained in 62.5% of patients. There was no reported case of death from HAE so far.

CONCLUSIONS

The clinical manifestation and severity of HAE may vary according to ethnicity. HAE is more infrequent and GI involvement is less likely in Korea compared with Western 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.

Diminished capacity of opsonization and immune complex solubilization, and detection of anti-C1q antibodies in sera from patients with hereditary angioedema

BACKGROUND

Hereditary angioedema (HAE) is an autosomal dominant disease caused by deficiency of C1 esterase inhibitor. Symptoms of HAE include edema, which can potentially cause suffocation. Some patients with HAE exhibit immunological abnormalities, which could prevent an accurate diagnosis. Low levels of complement components are characteristic of HAE and in other settings are thought to reduce elimination of apoptotic cells and immune complex (IC). Thus, we aimed to experimentally clarify the mechanism of immunological abnormalities using sera from HAE patients.

METHODS

Serum samples from 18 patients with HAE were collected when free from angioedema attack and compared with normal human pooled sera (NHPS) from 20 healthy volunteers. Opsonization was measured as the rate of phagocytosis of apoptotic Jurkat cells by macrophages differentiated from THP-1 cells incubated with serum. IC solubilization in serum was analyzed by quantifying peroxidase released from a synthetic IC composed of peroxidase and anti-peroxidase antibodies. Anti-C1q antibody levels were detected using an enzyme-linked immunosorbent assay.

RESULTS

Serological immunological abnormalities were detected in 12 patients. Opsonization in serum samples from each patient with HAE was lower than that in NHPS (∼20% versus 70%, respectively). The rate of IC solubilization was lower in serum from HAE patients than NHPS. Some patients had high serum anti-C1q antibody levels with increased serum IC levels.

CONCLUSIONS

Sera from patients with HAE exhibit anti-C1q antibodies, with a lower capacity for opsonization and IC solubilization. This may be associated with immunological abnormalities and should be investigated further to facilitate accurate diagnosis of HAE.

Misdiagnosis trends in patients with hereditary angioedema from the real-world clinical setting

BACKGROUND

Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) causes swelling in the skin and upper airways and pain in the abdomen because of mucosal swelling. C1-INH-HAE is frequently misdiagnosed, leading to delays in diagnosis, inadequate treatment, and unnecessary procedures.

OBJECTIVE

To evaluate the history of misdiagnosis in patients participating in the Icatibant Outcome Survey (IOS).

METHODS

The IOS is an observational study in which safety and effectiveness of icatibant have been evaluated since 2009. As part of the IOS, patients record any misdiagnoses received before being diagnosed as having C1-INH-HAE.

RESULTS

In January 2016, a total of 418 of 633 IOS patients with C1-INH-HAE type I or II had provided misdiagnosis data. Of these, 185 of 418 (44.3%) received 1 or more prior misdiagnoses. The most common misdiagnoses were allergic angioedema (103 of 185) and appendicitis (50 of 185). A variety of other misdiagnoses were reported, including a substantial number of gastrointestinal disorders (excluding appendicitis). Misdiagnosis rates were similar between males (41.1%) and females (46.5%) and between C1-INH-HAE type I (43.7%) and type II (51.6%). Patients with family members diagnosed as having C1-INH-HAE were significantly less likely to be misdiagnosed than patients without a family history (140 of 366 [41.7%] vs 38 of 58 [65.5%], respectively; P = .001). Patients with a prior misdiagnosis had longer median delay to C1-INH-HAE diagnosis (13.3 years) than patients without (1.7 years; P < .001).

CONCLUSION

From this large database, approximately 50% of patients with C1-INH-HAE type I or II have previously had their conditions misdiagnosed, most commonly as allergic angioedema or appendicitis. Misdiagnosis results in marked delays in receiving the correct diagnosis, during which time patients cannot access effective, lifesaving treatment.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01034969.

The Humanistic, Societal, and Pharmaco-economic Burden of Angioedema

Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) is a rare disorder characterized by intermittent and unpredictable episodes of swelling which cause disfigurement, disability, pain, or, in case of laryngeal swelling, risk of death. Historical factors, including the intermittent nature of the disorder, the lack of awareness of this ultra-rare condition amongst medical personnel, lack of specialist centers, and limited treatment options have contributed to under-diagnosis and under-treatment of the condition. Incorrect treatment of attacks has been common, even when medical help is sought. This has lead to reduced health-seeking behavior and alternative coping strategies, sometimes even denial, in many families, while a minority of HAE-affected patients have become serial emergency room attenders with chronic pain and ongoing requirement for opiate-based painkillers. Both strategies have incurred not only physical but also psychological and economic consequences.In the last 10 years, new and effective acute therapies have been made available, some of which have also provided short-term and long-term prophylaxis options, together with a better understanding of older prophylactic drugs. Improved awareness of HAE amongst the general public, family members, and physicians has reduced the long delay in diagnosis and increased the number of patients receiving effective and up-to-date therapies to improve the physical impact of the disorder.Data on the impact of treatment on the psychological outcomes is scarce, but the limited information available suggests that access to specialist advice and treatment leads to psychological as well as physical improvement.HAE also has profound effects on individual and family economic output, directly via absenteeism from school or work and indirectly via lost opportunities. Economic improvements associated with better treatments are offset by the high cost of new acute treatments, resulting in difficult pharmaco-economic calculations. Worldwide, cost considerations present potentially insurmountable barriers to treatment for many patients, depending on the healthcare system in the individual country.

International consensus on the diagnosis and management of pediatric patients with hereditary angioedema with C1 inhibitor deficiency

Background

The consensus documents published to date on hereditary angioedema with C1 inhibitor deficiency (C1‐INH‐HAE) have focused on adult patients. Many of the previous recommendations have not been adapted to pediatric patients. We intended to produce consensus recommendations for the diagnosis and management of pediatric patients with C1‐INH‐HAE.

Methods

During an expert panel meeting that took place during the 9th C1 Inhibitor Deficiency Workshop in Budapest, 2015 (www.haenet.hu), pediatric data were presented and discussed and a consensus was developed by voting.

Results

The symptoms of C1‐INH‐HAE often present in childhood. Differential diagnosis can be difficult as abdominal pain is common in pediatric C1‐INH‐HAE, but also commonly occurs in the general pediatric population. The early onset of symptoms may predict a more severe subsequent course of the disease. Before the age of 1 year, C1‐INH levels may be lower than in adults; therefore, it is advisable to confirm the diagnosis after the age of one year. All neonates/infants with an affected C1‐INH‐HAE family member should be screened for C1‐INH deficiency. Pediatric patients should always carry a C1‐INH‐HAE information card and medicine for emergency use. The regulatory approval status of the drugs for prophylaxis and for acute treatment is different in each country. Plasma‐derived C1‐INH, recombinant C1‐INH, and ecallantide are the only agents licensed for the acute treatment of pediatric patients. Clinical trials are underway with additional drugs. It is recommended to follow up patients in an HAE comprehensive care center.

Conclusions

The pediatric‐focused international consensus for the diagnosis and management of C1‐INH‐HAE patients was created.