The analysis of the effect of the COVID-19 pandemic on patients with hereditary angioedema type I and type II.

Due to the similarity between the pathomechanism of SARS-CoV-2 infections and hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE), a possibility emerged that C1-INH-HAE may worsen the course of the infection, or that the infection may influence the severity of angioedema (HAE) attacks in C1-INH-HAE patients. Our study aimed to evaluate the effects of the COVID-19 pandemic on the quality of life (QoL) of Hungarian C1-INH-HAE patients, and to survey the acute course of the infection, post COVID symptoms (PCS), vaccination coverage and the side effects of vaccines in this patient population. 93 patients completed our questionnaire between 1st July 2021 and 31st October 2021. In this same period and between March 2019 and March 2020, 63 patients completed the angioedema quality of life questionnaire (AE-QoL). Out of those patients infected with SARS-CoV-2 in the examined period (18/93 patients; 19%), 5% required hospitalization, 28% experienced HAE attacks in the acute phase of the infection, and 44% experienced PCS. A total number of 142 doses of vaccines were administered to the patients. Serious vaccine reactions did not occur in any case, 4 (5%) out of the 73 vaccinated patients experienced HAE attacks. No significant difference (p = 0.59) was found in the median of the AE-QoL total score, or in the number of HAE attacks prior and during the pandemic. Based on our study, HAE patients did not experience more serious SARS-CoV-2 infection, and it did not aggravate the course of HAE either. Changes in the QoL were not significant, and vaccines were safe in HAE patients.

Recurrent abdominal pain as the only clinical manifestation of hereditary angioedema type II.

Recurrent abdominal pain is a common reason for consultation in Gastroenterology. The differential diagnosis includes hereditary angioedema (HAE), a rare disorder characterized by recurrent episodes of angioedema, without urticaria or pruritus, which most often affects the skin, but also mucosal tissues of the gastrointestinal tract, triggered by diverse factors such as infections, trauma, surgery, drugs, or stress. It is a disease with a difficult diagnosis due to its heterogeneous and transitory clinical features, so having a clinical suspicion in the appropriate context would allow the administration of a specific treatment and avoid unnecessary examinations. We present the case of a 19-year-old male followed-up for recurrent abdominal pain that, after numerous microbiological, endoscopic, and radiological examinations, complement tests were requested, obtaining low levels of C4 with increased levels of C1 inhibitor and reduced functional activity, being diagnosed with HAE type II.

Management of pediatric hereditary angioedema types 1 and 2: A search for international consensus.

Background: The management of hereditary angioedema has rapidly changed over the past decade. With these changes there has been increased recognition of the unique challenges of diagnosing and managing hereditary angioedema in pediatric populations. The objective of this review was to identify and compare recently published consensus guidelines for the management of hereditary angioedema types 1 and 2 to identify areas of agreement and conflict. Methods: A MEDLINE database search was performed to identify guidelines that offered guidance on diagnosing or managing hereditary angioedema in pediatric populations. A limitation was placed on guidelines published in the past 5 years to reflect the most recent literature. Results: Six clinical practice guidelines were included in the analysis. Early detection of disease status, coordination with specialists, and empowering patients with self-administered medications are emphasized, with use of plasma derived C1 esterase inhibitor as first line therapy for aborting attacks. The guidelines are shifting away from attenuated androgens and tranexamic acid for long-term prophylaxis toward medications such as subcutaneous C1 esterase inhibitor, lanadelumab, and berotralstat. Conclusion: Although some differences exist based on geographic region and health system where an included guideline was published, they have very minimal differences on close review.

Isolated angioedema: A review of classification and update on management.

OBJECTIVE: To review the various types of angioedema including diagnosis and treatment. DATA SOURCES: PubMed search of articles in the English language of various types of angioedema. STUDY SELECTIONS: Articles on the subject matter were selected and reviewed. RESULTS: Herein, a case-based approach is presented for discussing the major types of angioedema, including the following: hereditary angioedema types I and II and normal complement, acquired angioedema, angiotensin-converting enzyme-induced angioedema, and histaminergic and nonhistaminergic angioedema. Emerging treatments of hereditary angioedema including targets of prekallikrein, DNA vector technology replacing C1-INH protein, and CRIPSR technology targeting prekallikrein among many others are explored. In addition, other causes and mimickers of angioedema are briefly reviewed. Finally, a novel algorithm is proposed to help guide the treating physician through the workup and management of patients with suspected idiopathic angioedema unresponsive to conventional therapy with antihistamines. CONCLUSION: Over the years, many strides have been made in both understanding the pathophysiology of various types of angioedema and expansion of treatment options. It is important for clinicians to be aware of current and emerging treatment options. We provide a novel practical algorithm to guide clinicians in challenging cases of idiopathic angioedema refractory to antihistamines.

Genetic Study of Hereditary Angioedema Type I and Type II (First Report from Iranian Patients: Describing Three New Mutations).

BACKGROUND: Hereditary Angioedema (HAE) is a rare autosomal dominant immunodeficiency disease with mutation in C1 inhibitor gene (SERPING1) which deficient and dysfunction of C1-INH protein result in HAE type I or type II, respectively. The present study aimed to define the genetic spectrum of HAE type I and type II among Iranian patients. METHODS: Thirty-four patients with clinical phenotype of recurrent edematous attacks in face, upper and lower limbs, hands, and upper airway entered the study. Mutations in SERPING1 were analyzed using PCR and Sanger Sequencing. In addition, Multiplex Ligation-dependent Probe Amplification (MLPA) was performed to discover large deletions or duplications in negative screening samples by Sanger. RESULTS: Twenty-three patients were diagnosed with HAE type I and 11 with HAE type II. Fourteen distinctive pathogenic variations including five frameshift (p.G217Vfs*, p.V454Gfs*18, p.S422Lfs*9, p.S36Ffs*21, p.L243Cfs*9), seven missense (p.A2V, p.G493R, p.V147E, p.G143R, p.L481P, p.P399H, p.R466C), one nonsense (p.R494*), and one splicing defect (C.51 + 2 T˃C), which three of these mutations were identified novel. However, no mutation was found in seven patients by Sanger sequencing and MLPA. CONCLUSION: Final diagnosis with mutation analysis of HAE after clinical evaluation and assessment of C1INH level and function can prevent potential risks and life-threatening manifestations of the disorder. In addition, genetic diagnosis can play a significant role in facilitating early diagnosis, pre-symptomatic diagnosis, early diagnosis of children, asymptomatic cases, and those patients who have the borderline biochemical results of C1-INH deficiency and/or C4.

COVID-19 and hereditary angioedema: Incidence, outcomes, and mechanistic implications.

Background: Patients with hereditary angioedema (HAE) have been postulated to be at increased risk for coronavirus disease 2019 (COVID-19) infection due to inherent dysregulation of the plasma kallikrein-kinin system. Only limited data have been available to explore this hypothesis. Objective: To assess the interrelationship(s) between COVID-19 and HAE. Methods: Self-reported COVID-19 infection, complications, morbidity, and mortality were surveyed by using an online questionnaire. The participants included subjects with HAE with C1 inhibitor (C1INH) deficiency (HAE-C1INH) and subjects with HAE with normal C1-inhibitor (HAE-nl-C1INH), and household controls (normal controls). The impact of HAE medications was examined. Results: A total of 1162 participants who completed the survey were analyzed, including: 695 subjects with HAE-C1INH, 175 subjects with HAE-nl-C1INH, and 292 normal controls. The incidence of reported COVID-19 was not significantly different between the normal controls (9%) and the subjects with HAE-C1INH (11%) but was greater in the subjects with HAE-nl-C1INH (19%; p = 0.006). Obesity was positively correlated with COVID-19 across the overall population (p = 0.012), with a similar but nonsignificant trend in the subjects with HAE-C1INH. Comorbid autoimmune disease was a risk factor for COVID-19 in the subjects with HAE-C1INH (p = 0.047). COVID-19 severity and complications were similar in all the groups. Reported COVID-19 was reduced in the subjects with HAE-C1INH who received prophylactic subcutaneous C1INH (5.6%; p = 0.0371) or on-demand icatibant (7.8%; p = 0.0016). The subjects with HAE-C1INH and not on any HAE medications had an increased risk of COVID-19 compared with the normal controls (24.5%; p = 0.006). Conclusion: The subjects with HAE-C1INH who were not taking HAE medications had a significantly higher rate of reported COVID-19 infection. Subcutaneous C1INH and icatibant use were associated with a significantly reduced rate of reported COVID-19. The results implicated potential roles for the complement cascade and tissue kallikrein-kinin pathways in the pathogenesis of COVID-19 in patients with HAE-C1INH.

Variability of disease activity in patients with hereditary angioedema type 1/2: longitudinal data from the Icatibant Outcome Survey.

BACKGROUND: Hereditary angioedema due to C1 inhibitor deficiency (HAE-1/2) is a chronic and debilitating disease. The unpredictable clinical course represents a significant patient burden. OBJECTIVE: To analyse longitudinal registry data from the Icatibant Outcome Survey (IOS) in order to characterize temporal changes in disease activity in patients with HAE-1/2. METHODS: Icatibant Outcome Survey (NCT01034969) is an international observational registry monitoring the clinical outcomes of patients eligible for icatibant treatment. The current analyses are based on data collected between July 2009 and July 2019. Retrospective data for attacks recorded in the 12 months prior to IOS enrolment and for each 12-month period up to 7 years were analysed. RESULTS: Included patients reported angioedema attacks without long-term prophylaxis (LTP; n = 315) and with LTP (n = 292) use at the time of attack onset. Androgens were the most frequently used LTP option (80.8%). At the population level, regardless of LTP use, most patients (52-80%) reporting <5 attacks in Year 1 continued experiencing this rate; similarly, many patients (25-76%) who reported high attack frequency continued reporting ≥10 attacks/year. However, year on year, 31-51% of patients experienced notable changes (increase/decrease of ≥5 attacks) in annual attack frequency. Of patients who reported an absolute change of ≥10 attacks from Year 1 to 2, 17-50% continued to experience a change of this magnitude in subsequent years. CONCLUSION: At the population level, attack frequency was generally consistent over 7 years. At the small group level, 28.8-34.5% of patients reported a change in attack frequency of ≥5 attacks from Year 1 to Year 2; up to half of these patients continued to experience this magnitude of variation in disease activity in later years, reflecting high intra-patient variability.

Acquired angioedema in B cell lymphoproliferative disease: A retrospective case series.

Acquired angioedema due to C1-inhibitor (C1-INH) deficiency (AAE-C1-INH) is rare and is associated with underlying lymphoproliferative diseases. C1-INH deficiency may be due to neoplastic over-consumption of C1-INH and the generation of anti-C1-INH autoantibodies. Uncovering an occult malignancy can lead to earlier oncology referral and improvement of angioedema after treatment of the underlying lymphoproliferative disorder. We characterized seven patients with C1-INH-AAE that highlights the importance of recognizing the association between C1-INH-AAE and underlying malignancy. In acute attacks, patients may be resistant to C1-INH therapy due to the presence of anti-C1-INH autoantibodies or rapid complement consumption, and may respond better to icatibant or ecallantide, which directly affect bradykinin. Treatment of the underlying malignancy also improves AAE-C1-INH symptoms and supports the role of lymphoproliferative B cells in AAE-C1-INH pathophysiology. Monitoring levels of C4, C1-INH function and level, and C1q may be predictive of AAE-C1-INH control and be used as surrogates for treatment efficacy. With close monitoring, low-dose danazol can be effective for long-term prophylaxis. Annual evaluation in AAE-C1-INH is recommended if an underlying malignancy is not found, as angioedema may precede the development of malignancy by several years. Our single-center study has aided in standardization of comprehensive AAE-C1-INH diagnosis, treatment, and monitoring strategies towards future therapeutic clinical trials.

Management of hereditary angioedema type I and homozygous MTHFR mutation during pregnancy.

Hereditary angioedema (HAE) is an autosomal dominant disease, characterized by edema attacks resulting from quantitative and/or functional deficiency of the C1 inhibitor (C1-INH), which acts in controlling the complement, coagulation, fibrinolysis, and contact systems. The exacerbation of these systems results in decreased circulating levels of kallikrein and conversion of bradykinin. In addition, thrombophilia is related to the deficiency of methylenetetrahydrofolate reductase (MTHFR) enzyme, causing an increase in homocysteine, accumulation of atheromatous plaques, and arterial and venous thrombosis. The association of these conditions in related systems brings greater clinical risks to the patient. We report a female patient, aged 23 years, with HAE and homozygous MTHFR mutation, G2A1, carrier of HAE with crises since early childhood. The first pregnancy terminated with abortion due to gestational sac detachment. In the second pregnancy, at 5.1 weeks, she had bleeding and partial detachment of gestational sac. Thrombophilia tests confirmed homozygosity for the MTHFR enzyme. At the beginning of gestation, she had attacks of angioedema treated with fresh plasma, and at one occasion, she received treatment with a plasma-derived C1-INH esterase. During breastfeeding, she received prophylaxis with plasma-derived C1-INHdp. The course of HAE during pregnancy worsened. There are studies that discuss the occurrence of abortion due to attacks of angioedema. The patient's disease was associated with a homozygous MTHFR mutation, which probably caused the miscarriage. The control of both clinical situations is important for the success of pregnancy, so a combined action plan between obstetricians and HAE treatment specialists is essential.

Evidence for a dominant-negative effect of a missense mutation in the SERPING1 gene responsible for hereditary angioedema type I.

Hereditary angioedema (HAE) is a rare condition characterized by episodic local edema involving various organs, which can be life-threatening in some cases. Among the three subtypes of the disease, HAE types I and II are known to be caused by heterozygous mutations in the SERPING1 gene encoding C1 inhibitor (C1INH). Although a number of mutations in the SERPING1 gene have been identified to date, the mechanisms how these mutations cause HAE are not completely understood. We herein performed detailed in vitro studies for a missense SERPING1 gene mutation p.S150F which we recently identified in a Japanese patient with HAE type I. We showed that the p.S150F-mutant C1INH was stably expressed within the cultured cells, while it was not secreted into the medium at all. Furthermore, we demonstrated that the mutant C1INH significantly prevented secretion of wild-type C1INH. Finally, the results suggested that the wild-type protein was not only retained but also degraded within the cytoplasm through interacting with the mutant protein. Our study clearly revealed a dominant-negative effect of the p.S150F-mutant C1INH against the wild-type C1INH.

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.

HAE-AS: A Specific Disease Activity Scale for Hereditary Angioedema With C1-Inhibitor Deficiency.

BACKGROUND AND OBJECTIVE: The activity of hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE) varies between patients and within individual patients. Objective: This study aims to develop a disease activity scale for C1-INH-HAE (HAE-AS) with sound measurement properties. METHODS: Eleven countries participated in a prospective multicenter cohort study. A clinical questionnaire was self-completed by 290 adult patients with C1-INH-HAE. Patients also completed 2 quality of life scales, the SF-36v2 and the HAE-QoL. Rasch analysis and classic psychometric methods were used to preselect a series of clinical items: number of attacks by location and number of treated attacks, emergency room visits, psychological/psychiatric treatment, missed school/workdays in the previous 6 months; general health; and impairment in everyday work/activities due to pain. RESULTS: The mean (SD) age was 41.5 (14.7; range, 18-84) years, and 69% were females. The final 12-item Rasch model showed that the HAE-AS had satisfactory reliability (person separation index, 0.748), local item independence, unidimensionality, and no item bias by age or sex. The HAE-AS provided scores in a linear measure, with a mean of 10.66 (3.92; range, 0-30). Further analysis with classic psychometric methods indicated that the HAE-AS linear measure presented moderate-to-high convergent validity with quality of life scales (SF-36v2: physical component, r=-0.33; mental component, 0.555; HAE-QoL, -0.61), and good discriminative validity by age, sex, and disease severity (P<.05). CONCLUSIONS: The HAE-AS is a short, valid, reliable, and psychometrically sound measure of the activity of C1-INH-HAE that could prove useful for research studies.

Hereditary Angioedema Due to C1-Inhibitor Deficiency in Romania: First National Study, Diagnostic and Treatment Challenges.

BACKGROUND: Hereditary angioedema (HAE) is a rare genetic potentially life-threatening disease characterized by episodic non-pruritic subcutaneous and submucosal edema attacks in different parts of the body. OBJECTIVE: To assess the status of Romanian HAE patients after the recent introduction of a new therapy through a nationwide program. METHODS: This cross-sectional observational study included patients from the Romanian HAE Registry. RESULTS: The study included 84 patients with HAE type I (91.7%) and type II (8.3%). The mean delay in diagnosis was 2.4 years in children and 16.7 years in adults (p=0.019). Stress and tiredness were the most frequent trigger factors. The majority of the HAE episodes involved subcutaneous (89.3%), abdominal (77.4%), genital (51.2%), facial (41.7%), and laryngeal (39.3%) symptoms during the preceding 12 months. One or several misdiagnoses were reported in 83.33% patients and 44.1 % of the patients were subjected to or proposed unnecessary surgery during abdominal episodes. Plasma-derived C1-INH (pdC1-INH) and recombinant C1-INH (rhC1-INH) were respectively used in 10 (11.9%) and 13 (15.5%) of the HAE patients for life-threatening attacks over the past 12 months. Forty-three (51.19%) patients practiced home treatment with subcutaneous injection of the bradykinin B2-receptor antagonist for acute HAE attacks. CONCLUSION: The significantly lower delay observed in children suggests an improvement in the awareness of C1-INH-HAE among physicians in recent years. The management of HAE in Romania has been somewhat enhanced as the majority of HAE patients have recently gained access to pdC1-INH, rhC1-INH, and bradykinin B2-receptor antagonist.

Misleading symptoms of hereditary angioedema type II mimicking familial mediterranean fever.

Hereditary angioedema (HAE) is a rare, debilitating and potentially life-threatening disease characterized by recurrent attacks of oedema. With the development of new therapies and better availability of diagnostic tools, important advances have been made. However, the disease still remains frequently misdiagnosed and inadequately treated. Familial Mediterranean fever (FMF) is an autoinflammatory syndrome comprised of serositis, fever, arthritis and skin involvement. Both diseases can cause severe abdominal pain resembling that of acute abdomen. We report a case of three family members that presented with various symptoms that could fit in a clinical picture of both diseases, only to confirm a diagnosis of HAE type II after a diagnostic delay of many years.

Novel homozygous variants in the SERPING1 gene in two Turkish families with hereditary angioedema of recessive inheritance.

Hereditary angioedema as a result of deficiency of the C1 inhibitor (HAE-C1INH; MIM# 106100) is a rare autosomal disorder and affected individuals are generally heterozygous for dominant negative variants in the SERPING1 gene. Homozygosity for SERPING1 pathogenic variants was long considered to be embryonically lethal; however, five nonrelated families with a recessive HAE pattern have been described in the last decade. In this report, we functionally characterized two newly reported nonrelated, consanguineous families with a recessive presentation of HAE attributed to SERPING1 variants in the reactive center loop (family D; S438F) and gate (family A; I379T) regions. S438F heterozygotes (family D) showed variable levels of intact 105-kDa and cleaved/inactive 96-kDa isoforms of C1INH, whereas their homozygous relative presented only the 96-kDa band. Functional studies showed that S438F reduced C1INH interaction with target proteases in heterozygous (C1s, 32-38% of controls and FXIIa, 28-35% of controls) and homozygous (C1s, 18-24% of controls and FXIIa, 4-8% of controls) carriers, which is consistent with the more severe presentation of HAE in the family and decreased C1q levels in homozygous patients. By contrast, plasma C1INH from I379T heterozygotes (family A) showed normal C1INH/C1s binding (84-94% of controls) and no significant reduction in C1INH/FXIIa complexes (50-70% of controls). However, the homozygote failed to inhibit both C1s (25-42% of controls) and FXIIa (14-18% of controls). This profile is concordant with the less severe presentation of HAE in the family and the conserved C4 and C1q levels in heterozygous and homozygous patients.

Patterns of C1-Inhibitor/Plasma Serine Protease Complexes in Healthy Humans and in Hereditary Angioedema Patients.

C1-inhibitor (C1-INH) is an important regulator of the complement, coagulation, fibrinolytic and contact systems. The quantity of protease/C1-INH complexes in the blood is proportional to the level of the in vivo activation of these four cascade-like plasma enzyme systems. Parallel determination of C1-INH-containing activation complexes could be important to understand the regulatory role of C1-INH in diseases such as hereditary angioedema (HAE) due to C1-INH deficiency (C1-INH-HAE). We developed in-house ELISAs to measure the concentration of complexes of C1-INH formed with active proteases: C1r, C1s, MASP-1, MASP-2, plasma kallikrein, factor XIIa, factor XIa, and thrombin, as well as to determine total and functionally active C1-INH. We measured the concentration of the complexes in EDTA plasma from 6 healthy controls, from 5 with type I and 5 with type II C1-INH-HAE patients during symptom-free periods and from five patients during HAE attacks. We also assessed the concentration of these complexes in blood samples taken from one C1-INH-HAE patient during the kinetic follow-up of a HAE attack. The overall pattern of complexed C1-INH was similar in controls and C1-INH-HAE patients. C1-INH formed the highest concentration complexes with C1r and C1s. We observed higher plasma kallikrein/C1-INH complex concentration in both type I and type II C1-INH-HAE, and higher concentration of MASP-1/C1-INH, and MASP-2/C1-INH complexes in type II C1-INH-HAE patients compared to healthy controls and type I patients. Interestingly, none of the C1-INH complex concentrations changed significantly during HAE attacks. During the kinetic follow-up of an HAE attack, the concentration of plasma kallikrein/C1-INH complex was elevated at the onset of the attack. In parallel, C1r, FXIIa and FXIa complexes of C1-INH also tended to be elevated, and the changes in the concentrations of the complexes followed rather rapid kinetics. Our results suggest that the complement classical pathway plays a critical role in the metabolism of C1-INH, however, in C1-INH-HAE, contact system activation is the most significant in this respect. Due to the fast changes in the concentration of complexes, high resolution kinetic follow-up studies are needed to clarify the precise molecular background of C1-INH-HAE pathogenesis.