Hereditary angioedema with normal C1 esterase inhibitor: Current paradigms and clinical dilemmas.

Background: A diagnosis of hereditary angioedema (HAE) with normal C1 esterase inhibitor (HAE-nl-C1-INH) can be challenging and pharmacologic management is not well defined. Objective: The objective was to discuss practical considerations in the clinical management of HAE-nl-C1-INH by using illustrative clinical vignettes to highlight and/or address select challenges. Methods: This was a narrative review. Results: Symptoms of HAE-nl-C1-INH overlap with HAE types I and II; the heterogeneity of presentation and symptom burden are diagnostic challenges. A patient history, with particular attention to whether urticaria or other symptoms of mast cell mediator release are present, is important because such symptoms would strongly suggest a mast cell-mediated pathway. A family history of angioedema is informative but a lack thereof does not rule out diagnosis. Expected laboratory findings would be normal for C4, C1-INH level and function, and Complement 1q; a genetic mutational analysis may be helpful, but current assays do not include all known mutations; most cases are categorized as unknown. To align with guideline-directed treatment approaches, the following stepwise approach is suggested for suspected HAE-nl-C1-INH: (1) thoroughly investigate the possibility of response to histaminergic and/or mast cell-targeting treatments; (2) if patients with normal C4, C1-INH level and/or function fail adequate trials with histamine/mast cell-directed therapy or have a mutation that suggests bradykinin pathway involvement, follow HAE type I and II treatment guidelines. Response to medications approved for HAE types I/II provides compelling support for a high clinical suspicion of HAE-nl-C1-INH. De-labeling an HAE-nl-C1-INH diagnosis may be appropriate if the initial diagnosis was made without adequate evaluation or if new information and/or testing indicates that the patient does not actually have HAE. Conclusion: Key unmet needs in HAE-nl-C1-INH include lack of confirmatory biomarker(s) for diagnosis and lack of prospective controlled clinical studies of pharmacologic products in this patient population.

Repeated attacks of hereditary angioedema in pediatric female.

A 16-year-old female presented to an outpatient clinic with a 13-year history of recurrent episodes of abdominal pain, vomiting and mild cutaneous swelling, either spontaneously or following minor trauma. The episodes occurred every 1-2 months. There was no family history of a similar complaint or hereditary angio-oedema (HAE). At the age of 16, evaluation confirmed the diagnosis of HAE type II, characterised by low C4 levels and reduced C1 esterase inhibitor function. The patient was prescribed tranexamic acid 1 g twice daily as well as C1 esterase inhibitor used as rescue medication during symptomatic episodes. This case report emphasises the importance of considering a diagnosis of HAE in patients with recurrent, unexplained abdominal pain, even in the absence of a positive family history of HAE.Abbreviations: ANA Antinuclear antibodies; C1-INH C1-inhibitor; CBC Complete blood count; FMF Familial Mediterranean fever; HAE Hereditary angioedema; IBD Inflammatory bowel diseases; SDP Solvent detergent-treated plasma; SLE Lupus erythematosus.

Kallikrein inhibitors for angioedema: the progress of preclinical and early phase studies.

INTRODUCTION: Hereditary angioedema (HAE) is a rare genetic disorder characterized by recurrent edema and predominantly caused by the dysregulation of the kinin-kallikrein system. AREAS COVERED: This manuscript presents the results of preclinical and early clinical trials of newer drugs targeting the dysregulated kinin-kallikrein system. ATN-249 is an oral drug that has shown promising results in preclinical and Phase I studies, and good tolerability in the prophylactic treatment of attacks. KVD900 is also an oral agent developed for the on-demand treatment of HAE attacks. It has shown positive results in Phase I/II studies, with rapid absorption. The third drug, IONIS-PKKRx, is an antisense oligonucleotide targeting plasma prekallikrein mRNA. It has shown a dose-dependent reduction of plasma prekallikrein levels and proenzyme activation in Phase I/II studies, and has shown promising results. STAR-0215 is a long acting anti-activated kallikrein monoclonal antibody. A Phase 1a single ascending dose trial evaluated its safety, pharmacokinetics, and pharmacodynamics. Lastly, NTLA-2002 is an investigational gene-editing therapy. EXPERT OPINION: The targeted treatment of the dysregulated kinin-kallikrein system with specific inhibitors is promising for the prevention of angioedema attacks. Ongoing phase III studies will provide further insight into the efficacy and long-term safety of these novel therapies, potentially expanding treatment options for HAE treatment.

Vision loss due to atypical bilateral edema of the optic nerve in a patient with hereditary angioedema: A case report.

PURPOSE: To describe a rare case of vision loss due to bilateral edema of the optic nerve in a patient with Hereditary Angioedema, treated with prophylactic C1-esterase inhibitor. METHODS: A 60-year-old Caucasian male affected by Hereditary Angioedema with unknown genetic defect (HAE- UNK) was admitted to our hospital presenting bilateral vision loss (best corrected visual acuity of 20/32 in the right eye and hand motion in the left eye) during an HAE attack. Intravenous administration of C1- esterase inhibitor (C1-INH, 1500 IU, Berinert, CSL Behring) determined the resolution of facial and periorbital swelling, however visual impairment persisted, in contrast with previous attacks experienced by the patient. Fundus examination revealed a vital optic disc without papilledema in both eyes. Magnetic resonance imaging (MRI) of the head and orbits showed bilateral edema of the optic nerve sheath. Treatment with intravenous and oral steroids was ineffective. Subsequently, a prophylactic treatment strategy with subcutaneous C1-esterase inhibitor was started (7000 IU every four days). RESULTS: Complete regression of edema of the optic nerves was observed by imaging at two months of follow-up after chronic treatment with C1-esterase inhibitor (7000 IU every four days). Complete restoration of visual acuity was achieved (BCVA 20/20 in both eyes) and multimodal imaging of the optic nerves demonstrated the absence of anatomical and functional damage. CONCLUSION: Patients affected by HAE may show atypical presentation with edema of the optic nerves without involvement of the optic nerve head. They may significantly benefit from prophylactic and chronic treatment with C1-esterase inhibitor.

CRISPR-Cas9 In Vivo Gene Editing of KLKB1 for Hereditary Angioedema.

BACKGROUND: Hereditary angioedema is a rare genetic disease that leads to severe and unpredictable swelling attacks. NTLA-2002 is an in vivo gene-editing therapy based on clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9. NTLA-2002 targets the gene encoding kallikrein B1 (KLKB1), with the goal of lifelong control of angioedema attacks after a single dose. METHODS: In this phase 1 dose-escalation portion of a combined phase 1-2 trial of NTLA-2002 in adults with hereditary angioedema, we administered NTLA-2002 at a single dose of 25 mg, 50 mg, or 75 mg. The primary end points were the safety and side-effect profile of NTLA-2002 therapy. Secondary and exploratory end points included pharmacokinetics, pharmacodynamics, and clinical efficacy determined on the basis of investigator-confirmed angioedema attacks. RESULTS: Three patients received 25 mg of NTLA-2002, four received 50 mg, and three received 75 mg. At all dose levels, the most common adverse events were infusion-related reactions and fatigue. No dose-limiting toxic effects, serious adverse events, grade 3 or higher adverse events, or clinically important laboratory findings were observed after the administration of NTLA-2002. Dose-dependent reductions in the total plasma kallikrein protein level were observed between baseline and the latest assessment, with a mean percentage change of -67% in the 25-mg group, -84% in the 50-mg group, and -95% in the 75-mg group. The mean percentage change in the number of angioedema attacks per month between baseline and weeks 1 through 16 (primary observation period) was -91% in the 25-mg group, -97% in the 50-mg group, and -80% in the 75-mg group. Among all the patients, the mean percentage change in the number of angioedema attacks per month from baseline through the latest assessment was -95%. CONCLUSIONS: In this small study, a single dose of NTLA-2002 led to robust, dose-dependent, and durable reductions in total plasma kallikrein levels, and no severe adverse events were observed. In exploratory analyses, reductions in the number of angioedema attacks per month were observed at all dose levels. (Funded by Intellia Therapeutics; ClinicalTrials.gov number, NCT05120830.).

Tenecteplase-associated orolingual angioedema: A case report and literature review.

PURPOSE: Orolingual angioedema (OA) secondary to administration of thrombolytic therapy is a rare, but serious, known adverse effect. Despite the lack of robust evidence for their use, C1 esterase inhibitors are recommended by guidelines for the treatment of refractory thrombolytic-associated OA. This report highlights the use of a C1 esterase inhibitor in a patient with tenecteplase-associated OA unresolved by antihistamine and corticosteroid therapy. SUMMARY: A 67-year-old white male with a history of hypertension managed with lisinopril presented to the emergency department with acute onset of slurred speech and left-sided hemiparesis. Following workup, an outside hospital's neurology stroke team suspected an acute infarct and determined the patient to be a candidate for tenecteplase. Approximately 1 hour after tenecteplase administration, the patient began complaining of dyspnea and mild oral angioedema. Immediate interventions for OA management included intravenous therapy with dexamethasone 10 mg, diphenhydramine 25 mg, and famotidine 20 mg. After an additional 30 minutes, the patient's OA symptoms continued to progress and a C1 esterase inhibitor (Berinert) was administered. Shortly after administration of the C1 esterase inhibitor, the patient's symptoms continued to worsen, ultimately leading to endotracheal intubation. Following intubation, symptom improvement was noted, and the patient was safely extubated after 30 hours. CONCLUSION: Although rare, OA is a potentially life-threatening complication of tenecteplase therapy and requires prompt pharmacological intervention to optimize patient outcomes. Currently, no single agent or treatment algorithm exists that has shown significant efficacy or safety in the setting of thrombolytic-associated OA. Until data are available for C1 esterase inhibitors in this application, these inhibitors should only be considered if there is continued symptom progression after intravenous administration of corticosteroids and antihistamines.

COVID-19 infection and vaccination in patients with hereditary angioedema: a multicentric study.

Summary: Background. Due to similarities between the pathophysiological mechanisms of hereditary angioedema (HAE) and COVID-19, it has been hypothesized that SARS-CoV-2 infection may trigger HAE attacks or, alternatively, that HAE patients may experience different of COVID-19 disease severity. Furthermore, the potential for COVID-19 vaccination to trigger angioedema attacks in patients with HAE is still not completely defined. The objective is to characterize the exacerbations and clinical manifestations associated with COVID-19 infection and describe the adverse effects of COVID-19 vaccination in patients with HAE.Methods. Retrospective observational, descriptive, non-interventional, multicenter study conducted in four Allergy Units and Departments in Central Portugal between March 2020 and July 2022. HAE patient data were obtained from electronic medical records. Results. The study included 34 patients (67.6% female): 26 with HAE type 1, 5 with HAE type 2, and 3 with HAE with normal C1 inhibitor. Most patients with HAE type 1 and 2 were receiving long-term prophylaxis. Among the 32 patients who received COVID-19 vaccination, 86 doses, were administered with one angioedema attack (1.2%) associated with vaccination. A small increase in the average number of attacks was observed in the year following COVID vaccination (7.1 versus 6.2 in the previous year, p = 0.029), however, this difference is unlikely to be clinically significant, as the context of the COVID-19 pandemic likely introduced numerous confounders. During the study period, 16 HAE patients had COVID-19, all presenting with mild disease. Four out of 16 patients (25%) reported angioedema attacks during COVID-19, and 43.8% during the convalescence period (3 months after infection). Conclusions. Patients with HAE can safely receive COVID-19 vaccination. The severity of COVID-19 infection does not appear to be increased in HAE patients.

Delay in diagnosis is the most important proximate reason for mortality in hereditary angio-oedema: our experience at Chandigarh, India.

BACKGROUND: Hereditary angio-oedema (HAE) is a rare autosomal dominant disorder characterized clinically by recurrent episodes of nonpruritic subcutaneous and/or submucosal oedema. Laryngeal oedema is the commonest cause of mortality in patients with HAE. Prior to the availability of first-line treatment options for the management of HAE, mortality was as high as 30%. Mortality has significantly declined in countries where first-line treatment options are available and patients can access these therapies. There is a paucity of literature on the outcomes of patients with HAE in developing countries where availability of and access to first-line treatment options are still a challenge. OBJECTIVES: To report our experience on mortality in patients with HAE and to report factors associated with the death of these patients. METHODS: We carried out a record review of all patients diagnosed with HAE between January 1996 and August 2022. Families with HAE who had reported the death of at least one family member/relative from laryngeal oedema were studied in detail. RESULTS: Of the 65 families (170 patients) registered in the clinic, 16 families reported the death of at least one family member/relative from laryngeal oedema (total of 36 deaths). Of these 16 families, 14 reported that 1 or more family members had experienced at least 1 attack of laryngeal oedema. One patient died during follow-up when she was taking long-term prophylaxis with stanozolol and tranexamic acid, while the remaining 35 patients were not diagnosed with HAE at the time of their death. At the time of death of all 36 patients, at least 1 other family member had symptoms suggestive of HAE, but the diagnosis was not established for the family. CONCLUSIONS: To our knowledge, this is the largest single-centre cohort of patients with HAE in India reporting mortality data and factors associated with death in these families. The delay in diagnosis is the most important reason for mortality.

Hereditary angioedema outcomes in US patients switched from injectable long-term prophylactic medication to oral berotralstat.

BACKGROUND: Berotralstat, a first-line, once-daily, oral plasma kallikrein inhibitor for long-term prophylaxis of hereditary angioedema (HAE), is an effective and well-tolerated treatment option. OBJECTIVE: To summarize the safety, effectiveness, and impact on treatment satisfaction in patients who switched from injectable long-term prophylactics to oral berotralstat monotherapy (150 mg daily) at US sites in the international open-label APeX-S study. METHODS: APeX-S was an open-label, Phase II study of berotralstat conducted in 22 countries. Here, we focus on APeX-S patients enrolled at US sites who switched from injectable long-term prophylactics to berotralstat 150 mg once-daily monotherapy. RESULTS: A total of 34 patients discontinued lanadelumab (n = 21), subcutaneous C1 esterase inhibitor (n = 11), or intravenous C1 esterase inhibitor (n = 2) and switched to berotralstat 150 mg monotherapy. Vomiting, diarrhea, and upper respiratory tract infection were the most common adverse events (each 11.8%). Mean monthly attack rates were consistently low after the switch to berotralstat. The mean (SEM) monthly attack rate was 0.29 (0.11) at Month 1, 0.48 (0.15) at Month 6, and 0.58 (0.23) at Month 12. The median attack rate was 0 attack/mo throughout 12 months of treatment. Improvements were observed in the Treatment Satisfaction Questionnaire for Medication from baseline to Month 12 after the switch to berotralstat monotherapy, with the greatest improvements in convenience. CONCLUSION: The transition from injectable prophylactic medication to berotralstat was generally well tolerated. Patients switching to berotralstat monotherapy maintained good control of their HAE symptoms and reported improved treatment satisfaction. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03472040.

A phase 2 open-label extension study of prekallikrein inhibition with donidalorsen for hereditary angioedema.

BACKGROUND: Hereditary angioedema (HAE) is a potentially fatal disease characterized by unpredictable, recurrent, often disabling swelling attacks. In a randomized phase 2 study, donidalorsen reduced HAE attack frequency and improved patient quality-of-life (ISIS721744-CS2, NCT04030598). We report the 2-year interim analysis of the phase 2 open-label extension (OLE) study (ISIS 721744-CS3, NCT04307381). METHODS: In the OLE, the on-treatment study period consisted of fixed (weeks 1-13, donidalorsen 80 mg subcutaneously every 4 weeks [Q4W]) and flexible (weeks 17-105, donidalorsen 80 mg Q4W, 80 mg every 8 weeks [Q8W], or 100 mg Q4W) dosing periods. The primary outcome was incidence and severity of treatment-emergent adverse events (TEAEs). The secondary outcomes included efficacy, pharmacodynamic, and quality-of-life assessments. RESULTS: Seventeen patients continued in the OLE study. No serious TEAEs or TEAEs leading to treatment discontinuation were reported. Mean monthly HAE attack rate was 96% lower than the study run-in baseline rate (mean, 0.06/month; 95% confidence interval [CI], 0.02-0.10; median, 0.04 on-treatment vs. mean, 2.70/month; 95% CI, 1.94-3.46; median, 2.29 at baseline). Mean monthly attack rate for Q8W dosing (n = 8) was 0.29 (range, 0.0-1.7; 95% CI, -0.21 to 0.79; median, 0.00). Mean plasma prekallikrein and D-dimer concentrations decreased, and Angioedema Quality of Life Questionnaire total score improved from baseline to week 105 with donidalorsen. CONCLUSION: The 2-year interim results of this phase 2 OLE study of donidalorsen in patients with HAE demonstrated no new safety signals; donidalorsen was well tolerated. There was durable efficacy with a 96% reduction in HAE attacks.

Clinical Evaluation of Pediatric Patients with Hereditary Angioedema.

Hereditary angioedema is a rare, potentially life-threatening disease. There is a lack of data describing the clinical course of hereditary angioedema (HAE) in children. We aimed to evaluate the clinical characteristics of pediatric patients with hereditary angioedema: The age of disease onset, age at diagnosis, the frequency of angioedema attacks, the total number of attacks before diagnosis, the regions where angioedema attacks were observed, accompanying abdominal pain, and serum levels of C4 and C1 esterase inhibitor were obtained and recorded. In addition, the results of SERPING1 (C1INH) gene sequence analysis of the patients in this group were also collected from medical records and recorded. While none of the patients reported a skin rash as a symptom of attack, there was formication observed in the region of angioedema in 46.9% (n = 15) of the patients and pruritus in 6.2% (n = 2) of the patients. At disease onset, the complaints of the patients regarding location of edema were on the hands of 32.3% (n = 10), on the feet of 9.7% (n = 3), on the faces of 25.7% (n = 8), and abdominal attacks in 32.3% of the patients (n = 10). Four different variants, one of which was novel, were detected in the SERPING1 gene in eight different families. The results of this study suggest that hereditary angioedema is diagnosed only when the patient requests examination following recurrent angioedema. Severe laryngeal edema attacks in patients without a diagnosis of HAE are fatal at a higher rate than attacks in patients with a diagnosis. Thus, awareness of the symptoms of HAE is necessary, and correct diagnosis is essential to proper treatment.

Clinical Progress in Hepatic Targeting for Novel Prophylactic Therapies in Hereditary Angioedema.

Hereditary angioedema (HAE) is typically caused by a deficiency of the protease inhibitor C1 inhibitor (C1INH). The absence of C1INH activity on plasma kallikrein and factor XIIa leads to overproduction of the vasoactive peptide bradykinin, with resulting angioedema. As the primary site of C1INH and prekallikrein production, the liver is recognized as an important therapeutic target in HAE, leading to the development of hepatic-focused treatment strategies such as GalNAc-conjugated antisense technology and gene modification. This report reviews currently available data on hepatic-focused interventions for HAE that have advanced into human trials. Donidalorsen is an investigational GalNAc3-conjugated antisense oligonucleotide that binds to prekallikrein mRNA in the liver and reduces the expression of prekallikrein. Phase 2 data with subcutaneous donidalorsen demonstrated a significant reduction in HAE attack rate compared with placebo. Phase 3 trials are underway. ADX-324 is a GalNAc3-conjugated short-interfering RNA being investigated in HAE. BMN 331 is an investigational AAV5-based gene therapy vector that expresses wild-type human C1INH and is targeted to hepatocytes. A single intravenous dose of BMN 331 is intended to replace the defective SERPING1 gene and enable patients to produce functional C1INH. A first-in-human phase 1/2 study is ongoing with BMN 331. NTLA-2002 is an investigational in vivo clustered regularly interspaced short palindromic repeats/Cas9-based therapy designed to knock out the prekallikrein-coding KLKB1 gene in hepatocytes; a phase 1/2 study is ongoing. Findings from these and other ongoing studies are highly anticipated with the expectation of expanding the array of treatment options in HAE.

An expert panel's review on patients with hereditary angioedema switching from attenuated androgens to oral prophylactic therapy.

Background: Hereditary angioedema (HAE) is a rare condition marked by swelling episodes in various body parts, including the extremities, upper airway, face, intestinal tract, and genitals. Long-term prophylaxis (LTP), prescribed to control recurring HAE attacks, is integral to its management. Previously, attenuated androgens (AAs) were the only oral LTP options. However, in 2020, berotralstat, an oral plasma kallikrein inhibitor, was approved in the United States. A 2018 survey of adults with HAE type I or type II showed that almost all the patients who used prophylactic HAE medication preferred oral treatment (98%) and felt that it fit their lifestyle better than injectable treatment (96%). Still, guidelines lack consensus on transitioning patients from AAs to alternative oral prophylactic therapy. Objective: This paper aims to share expert insights and patient feedback on transitioning from AAs to berotralstat, an alternative oral prophylactic therapy, from the perspective of clinicians with extensive experience in treating patients with HAE. Methods: A panel of five HAE specialists convened for a virtual half-day roundtable discussion in April 2023. Results: Discussions about transitioning from AAs to berotralstat were prompted by routine consultations, patient inquiries based on independent research, ineffective current treatment, or worsening AA-related adverse effects. For patients who switched from AAs, the physicians reported that the decision was influenced by the alternative therapy's ability to prevent HAE attacks, its safety, and the once-daily administration schedule. All expert panel members identified fewer AA-related adverse effects; better quality of life; and less severe, shorter, and less frequent HAE attacks as clinical or patient goals they hoped to achieve through the treatment switch. Conclusion: The emergence of new, highly specific LTP drugs for HAE calls for the development of comprehensive recommendations and guidelines for transitioning from AAs to alternative oral prophylactic therapy. The expert panel highlighted key factors to consider during the development of such guidelines.

Once-Daily Oral Berotralstat for Long-Term Prophylaxis of Hereditary Angioedema: The Open-Label Extension of the APeX-2 Randomized Trial.

BACKGROUND: Berotralstat is a first-line, once-daily oral plasma kallikrein inhibitor approved for prophylaxis of hereditary angioedema (HAE) attacks in patients 12 years or older. OBJECTIVE: This analysis examined the safety and effectiveness of long-term prophylaxis with berotralstat. METHODS: APeX-2 was a phase 3, parallel-group, multicenter trial in patients with HAE caused by C1-inhibitor deficiency (NCT03485911). Part 1 was a randomized, double-blind, placebo-controlled evaluation of 150 and 110 mg of berotralstat over 24 weeks. In part 2, berotralstat-treated patients continued the same treatment, and placebo-treated patients were re-randomized to 150 or 110 mg of berotralstat for 24 weeks. In part 3, all patients were treated with open-label berotralstat at 150 mg, which could be continued for up to an additional 4 years. In part 3, the primary endpoint was long-term safety and tolerability. Secondary endpoints included HAE attack rates and quality of life (QoL). RESULTS: Eighty-one patients entered part 3. Treatment-emergent adverse events (TEAEs) occurred in 82.7% of patients, with most being mild or moderate in severity. The most common TEAEs were nasopharyngitis, urinary tract infection, abdominal pain, arthralgia, coronavirus infection, and diarrhea. Drug-related TEAEs occurred in 14.8% of patients, but none were serious. For patients who completed 96 weeks of berotralstat treatment (n = 70), the mean (standard error) change in attack rate from baseline was -2.21 (0.20) attacks/mo. Clinically meaningful improvements in QoL were also observed, with the largest improvements in the functioning domain. CONCLUSION: Berotralstat was generally well tolerated, provided rapid and sustained reductions in HAE attacks and improved QoL over 96 weeks.

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

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

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

BACKGROUND: Acquired angioedema with C1-inhibitor deficiency (AAE-C1-INH) is a rare condition resembling hereditary angioedema (HAE), but with late onset and low C1-inhibitor (C1-INH) due to consumption potentially caused by autoimmune diseases and mainly lymphatic malignancies. Being about 10-fold rarer than HAE, there is limited knowledge and no licensed therapy. OBJECTIVE: To report clinical and biological data from a newly described population of 20 patients with AAE-C1-INH assessing diagnostic delay, AAE-C1-INH:HAE-ratio, underlying conditions, and therapeutic management in Germany. METHODS: Retrospective data analysis of 20 patients from 2 angioedema centers in southern Germany. RESULTS: Median age at symptoms' onset was 64 years (60% females), with predominant swellings of the face (85%) and low levels for C1-INH in almost all patients. The ratio AAE-C1-INH:HAE was 1:9.7. From symptoms' onset to diagnosis of AAE-C1-INH, the median delay was 7.5 months, and between AAE-C1-INH symptoms' onset and diagnosis of the underlying hematological condition (n = 9) it was 4 months (median). Four patients had a history of solid neoplasm, 1 had a papillary thyroid carcinoma as the only potential cause for AAE-C1-INH, with treatment of the malignancy resulting in resolution of AAE-C1-INH. All the symptomatic patients were treated with off-label on-demand icatibant subcutaneously or C1-INH concentrate intravenously, and 6 severely affected patients needed off-label long-term prophylaxis with good symptom control. CONCLUSIONS: AAE-C1-INH is characterized by late-onset swellings mainly involving the face and low C1-INH levels. Diagnostic delay for AAE-C1-INH is further decreasing despite being about 10-fold rarer than HAE. Patients severely affected without underlying condition or no indication for treatment could benefit from off-label therapy.

Angioedema With Normal Complement Studies: What Do We Know?

Angioedema is generally readily recognizable clinically and is characterized by localized nonpitting edema involving subcutaneous, submucosal, or deep dermal tissue caused by increased vascular permeability and extravasation of intravascular fluid. It can occur via a variety of mechanisms. A number of clinical conditions (masqueraders) are occasionally mistaken for angioedema. Clinical classification of the various angioedema forms begins with noting the presence or absence of concurrent urticaria or wheals. Pathogenesis can be considered through two broad categories: mast cell-mediated with release of vasoactive mediators causing angioedema usually associated with urticaria or in the context of an anaphylactic reaction; and bradykinin (BK)-driven, in which increased vascular permeability is mediated by BK. BK-mediated angioedema does not occur with urticaria, nor does it respond to antiallergic medications. The various forms of hereditary angioedema are included in this category, requiring specific tests of C4 and C1 inhibitor level and function to confirm the diagnosis. Angiotensin converting enzyme inhibitors, which impair the degradation of BK, account for up to a third of all patients with angioedema presenting to the emergency department. Finally, angioedema may occur by yet unknown mechanisms; under this circumstance, it is difficult to manage.