DAB2IP associates with hereditary angioedema: Insights into the role of VEGF signaling in HAE pathophysiology.

BACKGROUND: In the recent years, there was an important improvement in the understanding of the pathogenesis of hereditary angioedema (HAE). Notwithstanding, in a large portion of patients with unknown mutation (HAE-UNK) the genetic cause remains to be identified. OBJECTIVES: To identify new genetic targets associated with HAE, a large Argentine family with HAE-UNK spanning 3 generations was studied. METHODS: Whole exome sequencing was performed on affected family members to identify potential genetic variants associated with HAE-UNK. In silico analyses and experimental studies were applied to assess the role of the identified gene variant. RESULTS: A missense variant (p.D239N) in DAB2IP was identified. The variant occurred in the C2-domain, the region interacting with vascular endothelial growth factor receptor 2 (VEGFR2). It was found to be rare, and predicted to have a detrimental effect on the functionality of DAB2IP. Protein structure modeling predicted changes in the mutant p.D239N protein structure, impacting protein stability. The p.D239N variant affected the subcellular localization of VEGFR2. Cells transfected with the DAB2IP-239N transcript exhibited an intracellular distribution, and VEGFR2 remained associated with the cell membrane. The altered localization pattern indicated reduced colocalization of the mutant protein with VEGFR2, suggesting a diminished ability of VEGFR2 binding. CONCLUSIONS: The study identified a novel missense variant (p.D239N) in DAB2IP in a family with HAE-UNK and highlighted the role of dysregulated VEGF-mediated signaling in altered endothelial permeability. DAB2IP loss-of-function pathogenic variants lead to the impairment of the endothelial VEGF/VEGFR2 ligand system and represent a new pathophysiologic cause of HAE-UNK.

Uncovering the true burden of hereditary angioedema due to C1-inhibitor deficiency: A focus on the Asia-Pacific region.

Hereditary angioedema (HAE) due to C1-inhibitor deficiency or dysfunction is a rare genetic disorder that causes recurrent episodes of swelling in various parts of the body. Treatment goals of HAE aim to "normalize" life for all patients; however, lack of diagnostic facilities and limited access to effective treatment options in developing nations cause delays in diagnosis and place a significant burden on patients. In this review, we aim to highlight the burden of disease caused by C1-inhibitor HAE across the Asia-Pacific region, considering its epidemiology, morbidity and mortality, and socioeconomic and psychological impact. We also review the availability of guideline-recommended diagnostic facilities and treatments, and how patients are currently managed. Data were collected from published literature and HAE experts in the region, who provided information regarding diagnosis and management in their countries. Current practice was reviewed against international guidelines, as well as local guidelines/consensus used in Australia, Japan, and China. Suggestions are provided for improving the time to diagnosis in the region, increasing access to guideline-recommended treatments, and providing support to reduce the burden on patients and caregivers. There is an urgent need to improve HAE services and provide access to life-saving treatment in developing countries, and efforts should be made to increase awareness of guideline recommendations in high-income economies that do not currently provide long-term prophylactic treatments.

Inter-α-trypsin inhibitor heavy chain 4 (ITIH4) as a compensatory protease inhibitor in hereditary angioedema.

BACKGROUND: Hereditary angioedema (HAE) is a genetic disorder that manifests as recurrent angioedema attacks, most frequently due to absent or reduced C1 inhibitor (C1INH) activity. C1INH is a crucial regulator of enzymatic cascades in the complement, fibrinolytic, and contact systems. Inter-α-trypsin inhibitor heavy chain 4 (ITIH4) is an abundant plasma protease inhibitor that can inhibit enzymes in the proteolytic pathways associated with HAE. Nothing is known about its role in HAE. OBJECTIVE: We investigated ITIH4 activation in HAE, establishing it as a potential biomarker, and explored its involvement in HAE-associated proteolytic pathways. METHODS: Specific immunoassays for noncleaved ITIH4 (intact ITIH4) and an assay detecting both intact and cleaved ITIH4 (total ITIH4) were developed. We initially tested serum samples from HAE patients (n = 20), angiotensin-converting enzyme inhibitor-induced edema patients (ACEI) (n = 20), and patients with HAE of unknown cause (HAE-UNK) (n = 20). Validation involved an extended cohort of 80 HAE patients (60 with HAE-C1INH type 1, 20 with HAE-C1INH type 2), including samples taken during attack and quiescent disease periods, as well as samples from 100 healthy controls. RESULTS: In 63% of HAE patients, intact ITIH4 assay showed lower signals than total ITIH4 assay. This difference was not observed in ACEI and HAE-UNK patients. Western blot analysis confirmed cleaved ITIH4 with low intact ITIH4 samples. In serum samples lacking intact endogenous ITIH4, we observed immediate cleavage of added recombinant ITIH4, suggesting continuous enzymatic activity in the serum. Confirmatory HAE cohort analysis revealed significantly lower intact ITIH4 levels in both type 1 and type 2 HAE patients compared to controls, with consistently low intact/total ITIH4 ratios during clinical HAE attacks. CONCLUSION: The disease-specific low intact ITIH4 levels highlight its unique nature in HAE. ITIH4 may exhibit compensatory mechanisms in HAE, suggesting its utility as a diagnostic and prognostic biomarker. The variations during quiescent and active disease periods raise intriguing questions about the dynamics of proteolytic pathways in HAE.

Prophylaxis in hereditary angioedema: a United Kingdom Delphi consensus.

Hereditary angioedema (HAE) is a rare inherited disorder causing recurrent episodes of swelling that can be potentially life threatening. Treatment of HAE can be divided into on-demand treatment for swelling, and prophylaxis. The last UK consensus on HAE was in 2014 and since then, new medications for prophylaxis have been developed, with more drugs in the pipeline. International guidelines currently recommend the use of long-term prophylaxis (LTP) as the only way of achieving disease control and normalizing patient lives. Modern prophylactic medications are available in the UK, although access is restricted primarily by HAE attack frequency. To establish an updated view of UK clinicians and patients, a Delphi process was used to develop statements regarding LTP as well as other aspects of HAE management. There was consensus that UK access criteria for modern LTP agents based on numerical frequency of attacks alone are too simplistic and potentially disadvantage a cohort of patients who may benefit from LTP. Additionally, there was agreement that patients should be seen in expert centres, remote monitoring of patients is popular post-pandemic, and that the use of patient-reported outcome measures has the potential to improve patient care. Psychological health is an area in which patients may benefit, and recognition of this is important for future research and development.

Patient-level indirect treatment comparison of lanadelumab versus pdC1-INH i.v. in hereditary angioedema patients: PATCH study.

BACKGROUND: Hereditary angioedema (HAE) is an autosomal dominant inherited disease in which patients suffer from local attacks primarily affecting skin and gastrointestinal tract, and sometimes even the upper respiratory tract leading to asphyxiation. Since head-to-head trials between authorized treatments are lacking, this study compares efficacy and safety of lanadelumab and intravenous plasma-derived C1-esterase inhibitor (pdC1-INH i.v.) in HAE patients on long-term prophylaxis by means of an indirect treatment comparison. METHODS: Efficacy and safety of lanadelumab against pdC1-INH i.v. were analyzed in a fully prespecified indirect comparison based on individual patient data (n = 231) from the HELP and CHANGE clinical trials. Primary and secondary efficacy endpoints were compared using a generalized linear model for count data. Confounding variables were identified a priori via systematic literature research and validated by clinical experts. Adjustment of confounders was implemented using a conditional regression model. RESULTS: Lanadelumab showed a statistically significant improvement in reduction of HAE attack rates compared to pdC1-INH i.v. across multiple endpoints: Monthly attack rate of patients treated with lanadelumab was less than half compared to pdC1-INH i.v. (Rate ratio: 0.486; 95% CI: 0.253, 0.932). Monthly rate of laryngeal attacks was found to be five times lower for lanadelumab (Rate ratio: 0.2; 95% CI: 0.044, 0.915) and monthly rate of acute treated HAE attacks among lanadelumab patients was about one third of the attack rate of pdC1-INH i.v. patients (Rate ratio: 0.366; 95% CI: 0.185, 0.727). CONCLUSION: This study contributes to current knowledge in the treatment of HAE by indicating a statistically significant reduction of HAE attacks under lanadelumab compared to pdC1-INH i.v.

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.

The Burden of Hereditary Angioedema in a Large Family in Brazil.

INTRODUCTION: Hereditary angioedema (HAE) is a rare genetic disease characterized by submucosal and subcutaneous edema with high morbidity and possibility of mortality. This study presents the sociodemographic characteristics of a large Brazilian family with HAE. METHODS: Descriptive cross-sectional study with patients from two family branches coming from the same city and HAE diagnosis was carried out. Clinical, laboratory, and treatment data of patients have been collected. Genetic testing was performed on some individuals. Correlation tests and comparisons between variables were applied using IBM SPSS Statistics® 2.0 program. RESULTS: We provide a detailed characterization of two families affected by HAE due to C1-INH deficiency, residing in a small town in southern Brazil. These families harbor an identified mutation in the SERPING1 gene (c.1104del, p.Asp369ThrfsTer2). The mean age at HAE diagnosis was 16.7 (±14.0) years, with the mean onset of symptoms at 6.0 (±6.1) years of age. A correlation was observed between patients' current age and age at HAE diagnosis, with older patients being diagnosed later than younger individuals (p < 0.0001). On average, there were 16.8 emergency visits in the past year (±24.8), and 53.5% of patients reported at least one lifetime hospitalization. Notably, treatment modalities often diverged from consensus recommendations regarding optimal prophylaxis and management of HAE attacks. CONCLUSIONS: This study describes one of the largest known families with HAE in Brazil and highlights the significant impact of unfavorable social conditions on disease control.

A quantitative systems pharmacology model of plasma kallikrein-kinin system dysregulation in hereditary angioedema.

Hereditary angioedema (HAE) due to C1-inhibitor deficiency is a rare, debilitating, genetic disorder characterized by recurrent, unpredictable, attacks of edema. The clinical symptoms of HAE arise from excess bradykinin generation due to dysregulation of the plasma kallikrein-kinin system (KKS). A quantitative systems pharmacology (QSP) model that mechanistically describes the KKS and its role in HAE pathophysiology was developed based on HAE attacks being triggered by autoactivation of factor XII (FXII) to activated FXII (FXIIa), resulting in kallikrein production from prekallikrein. A base pharmacodynamic model was constructed and parameterized from literature data and ex vivo assays measuring inhibition of kallikrein activity in plasma of HAE patients or healthy volunteers who received lanadelumab. HAE attacks were simulated using a virtual patient population, with attacks recorded when systemic bradykinin levels exceeded 20 pM. The model was validated by comparing the simulations to observations from lanadelumab and plasma-derived C1-inhibitor clinical trials. The model was then applied to analyze the impact of nonadherence to a daily oral preventive therapy; simulations showed a correlation between the number of missed doses per month and reduced drug effectiveness. The impact of reducing lanadelumab dosing frequency from 300 mg every 2 weeks (Q2W) to every 4 weeks (Q4W) was also examined and showed that while attack rates with Q4W dosing were substantially reduced, the extent of reduction was greater with Q2W dosing. Overall, the QSP model showed good agreement with clinical data and could be used for hypothesis testing and outcome predictions.

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.

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.

Insights into the pathogenesis of hereditary angioedema using genetic sequencing and recombinant protein expression analyses.

BACKGROUND: The pathogenesis of hereditary angioedema (HAE) type I and type II is linked to defective C1 esterase inhibitor (C1-INH) encoded by the SERPING1 gene. There are substantial variabilities in the clinical presentations of patients with HAE that are not directly correlated to the serum levels of C1-INH. The impact of SERPING1 variants on C1-INH expression, structure, and function is incompletely understood. OBJECTIVE: To investigate the influence of SERPING1 variants on the C1-INH expression, structure, and function of 20 patients with HAE from 14 families with no prior genetic diagnosis. METHODS: Patients underwent whole-exome sequencing (WES). If no variants were identified, whole-genome sequencing (WGS) was performed. Except for the frameshift and large deletions, each C1-INH variant was recombinantly produced and, if synthesized and secreted, was subjected to structural, oligosaccharide, and functional analyses. RESULTS: We identified 11 heterozygous variants in the SERPING1 gene, of which 5 were classified as pathogenic (E85Dfs∗63, N166Qfs∗91, K201Qfs∗56, P399A, and R466H) and 6 as variants of uncertain significance (C130W, I224S, N272del, K273del, L349F, and F471C). Three large heterozygous deletions were discovered through WGS. Our data indicate that C130W, N272del, P399A, and F471C are poorly synthesized, I224S prevents proper C1-INH folding, and K273del impairs C1-INH function by adding an additional oligosaccharide. Further evaluation suggests that compound variant P399A/L349F contributes to a more severe clinical phenotype. CONCLUSIONS: Our combined approach of WES and WGS uncovered SERPING1 gene alternations in each patient. The recombinant protein production followed by systematic antigenic, structural, and functional assessment facilitates the identification of underlying pathogenic mechanisms in HAE.

Restriction of C1-inhibitor activity in hereditary angioedema by dominant-negative effects of disease-associated SERPING1 gene variants.

BACKGROUND: Patients with hereditary angioedema experience recurrent, sometimes life-threatening, attacks of edema. It is a rare genetic disorder characterized by genetic and clinical heterogenicity. Most cases are caused by genetic variants in the SERPING1 gene leading to plasma deficiency of the encoded protein C1 inhibitor (C1INH). More than 500 different hereditary angioedema-causing variants have been identified in the SERPING1 gene, but the disease mechanisms by which they result in pathologically low C1INH plasma levels remain largely unknown. OBJECTIVES: The aim was to describe trans-inhibitory effects of full-length or near full-length C1INH encoded by 28 disease-associated SERPING1 variants. METHODS: HeLa cells were transfected with expression constructs encoding the studied SERPING1 variants. Extensive and comparative studies of C1INH expression, secretion, functionality, and intracellular localization were carried out. RESULTS: Our findings characterized functional properties of a subset of SERPING1 variants allowing the examined variants to be subdivided into 5 different clusters, each containing variants sharing specific molecular characteristics. For all variants except 2, we found that coexpression of mutant and normal C1INH negatively affected the overall capacity to target proteases. Strikingly, for a subset of variants, intracellular formation of C1INH foci was detectable only in heterozygous configurations enabling simultaneous expression of normal and mutant C1INH. CONCLUSIONS: We provide a functional classification of SERPING1 gene variants suggesting that different SERPING1 variants drive the pathogenicity through different and in some cases overlapping molecular disease mechanisms. For a subset of gene variants, our data define some types of hereditary angioedema with C1INH deficiency as serpinopathies driven by dominant-negative disease mechanisms.

Phenotypic and Genotypic Characterization of Hereditary Angioedema in Saudi Arabia.

Hereditary angioedema (HAE) is a potentially life-threatening autosomal dominant disorder affecting roughly 1:50,000 individuals. It is commonly characterized by swelling of the larynx, gastrointestinal tract, extremities, and skin. There is growing genetic heterogeneity associated with this disease but more than 95% of mutations are found in SERPING1, the gene which encodes complement 1 inhibitor (C1-INH). HAE cohorts from several populations have been published but no large scale study has been reported from the Arab world to date. Here we document the clinical and genetic findings of HAE patients from a single Saudi institution, which is a major referral center at the national level. A total of 51 patients across 17 unrelated families were recruited including two large multi-generational families, of which one contained an in-frame exonic deletion that was resolved through MLPA. Two cases were negative for all the genes we tested (including F12, PLG, ANGPT1, MYOF, KNG1, and HS3ST6). The predominant HAE subtype in our cohort was type I, at 76%. We were able to uncover a mutation in 49 patients (96%). No type III (normal C1-INH) patients were encountered in the clinic, suggesting that this subtype does not play a major role in HAE pathogenesis in Saudi Arabia. Additionally, the existence of four patients with consistently normal complement 4 (C4) levels alongside abnormal C1-INH profiles highlights the utility of dual screening for both proteins in suspected patients.

Systematic Approach Revealed SERPING1 Splicing-Affecting Variants to be Highly Represented in the Czech National HAE Cohort.

Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) is a rare and life-threatening condition characterized by recurrent localized edema. We conducted a systematic screening of SERPING1 defects in a cohort of 207 Czech patients from 85 families with C1-INH-HAE. Our workflow involved a combined strategy of sequencing extended to UTR and deep intronic regions, advanced in silico prediction tools, and mRNA-based functional assays. This approach allowed us to detect a causal variant in all families except one and to identify a total of 56 different variants, including 5 novel variants that are likely to be causal. We further investigated the functional impact of two splicing variants, namely c.550 + 3A > C and c.686-7C > G using minigene assays and RT-PCR mRNA analysis. Notably, our cohort showed a considerably higher proportion of detected splicing variants compared to other central European populations and the LOVD database. Moreover, our findings revealed a significant association between HAE type 1 missense variants and a delayed HAE onset when compared to null variants. We also observed a significant correlation between the presence of the SERPING1 variant c.-21 T > C in the trans position to causal variants and the frequency of attacks per year, disease onset, as well as Clinical severity score. Overall, our study provides new insights into the genetic landscape of C1-INH-HAE in the Czech population, including the identification of novel variants and a better understanding of genotype-phenotype correlations. Our findings also highlight the importance of comprehensive screening strategies and functional analyses in improving the C1-INH-HAE diagnosis and management.

Increased thromboinflammatory load in hereditary angioedema.

C1 inhibitor (C1Inh) is a serine protease inhibitor involved in the kallikrein-kinin system, the complement system, the coagulation system, and the fibrinolytic system. In addition to the plasma leakage observed in hereditary angioedema (HAE), C1Inh deficiency may also affect these systems, which are important for thrombosis and inflammation. The aim of this study was to investigate the thromboinflammatory load in C1Inh deficiency. We measured 27 cytokines including interleukins, chemokines, interferons, growth factors, and regulators using multiplex technology. Complement activation (C4d, C3bc, and sC5b-C9/TCC), haemostatic markers (ß-thromboglobulin (ß-TG), thrombin-antithrombin complexes (TAT), prothrombin fragment 1 + 2 (F1 + 2), active plasminogen activator inhibitor-1 (PAI-1), and the neutrophil activation marker myeloperoxidase (MPO) were measured by enzyme immunoassays. Plasma and serum samples were collected from 20 patients with HAE type 1 or 2 in clinical remission and compared with 20 healthy age- and sex-matched controls. Compared to healthy controls, HAE patients had significantly higher levels of tumour necrosis factor (TNF), interleukin (IL)-1ß, IL-2, IL-4, IL-6, IL-7, IL-9, IL-12, and IL-17A, chemokine ligand (CXCL) 8, chemokine ligand (CCL) 3, CCL4, IL-1 receptor antagonist (IL-1RA), granulocyte-macrophage colony-stimulating factor (GM-CSF), fibroblast growth factor (FGF) 2 and platelet-derived growth factor (PDGF)-BB. HAE patients also had higher levels of TAT and F1 + 2. Although granulocyte colony-stimulating factor (G-CSF), ß-TG and PAI-1 were higher in HAE patients, the differences did not reach statistical significance after correction for multiple testing. In conclusion, C1Inh deficiency is associated with an increased baseline thromboinflammatory load. These findings may reflect that HAE patients are in a subclinical attack state outside of clinically apparent oedema attacks.

CU06-1004 alleviates vascular hyperpermeability in a murine model of hereditary angioedema by protecting the endothelium.

BACKGROUND: Over-release of the vasoactive peptide bradykinin (BK) due to mutation in the SERPING1 gene is the leading cause of hereditary angioedema (HAE). BK directly activates endothelial cells and increases vascular permeability by disrupting the endothelial barrier, leading to angioedema affecting face, lips, extremities, gastrointestinal tract, and larynx. Although various pharmacological treatment options for HAE became available during the last decade, they are presently limited and pose a major economic burden on patients. To identify additional therapeutic options for HAE, we evaluated the effect of CU06-1004, an endothelial dysfunction blocker, on BK-induced vascular hyperpermeability and the HAE murine model. METHODS: To investigate the effect of CU06-1004 on BK-induced vascular hyperpermeability in vivo, we pre-administrated WT mice with the drug and then induced vascular leakage through intravenous injection of BK and observed vascular alternation. Then, SERPING1 deficient mice were used for a HAE murine model. For an in vitro model, the HUVEC monolayer was pre-treated with CU06-1004 and then stimulated with BK. RESULTS: Bradykinin disrupted the endothelial barrier and formed interendothelial cell gaps, leading to hyperpermeability in vivo and in vitro. However, CU06-1004 treatment protected the endothelial barrier by suppressing Src and myosin light chain activation via BK and alleviated hyperpermeability. CONCLUSION: Our study shows that CU06-1004 oral administration significantly reduced vascular hyperpermeability in the HAE murine model by protecting the endothelial barrier function against BK stimulation. Therefore, protecting endothelium against BK with CU06-1004 could serve as a potential prophylactic/therapeutic approach for HAE patients.

How Does Pregnancy and Type of Delivery Affect the Clinical Course of Hereditary Angioedema?

INTRODUCTION: Knowledge on the clinical course of hereditary angioedema (HAE) during pregnancy, delivery, and breastfeeding is very limited. In this study, we aimed to evaluate the course of HAE during these periods. METHODS: The HAE attacks C1-INH prophylaxis before and during pregnancy and during breastfeeding, and the delivery types were retrospectively determined. The severity of attacks was assessed by a 10-point Visual Analogue Scale (VAS). RESULTS: We evaluated 88 pregnancies in 48 HAE patients among whom 20 were primiparous. Among those who had a HAE diagnosis during pregnancy (n = 34), the median attack numbers before pregnancy, during pregnancy, breastfeeding, and after breastfeeding were 17, 39, 24, and 14 (before pregnancy vs. pregnancy, p < 0.001; during pregnancy vs. breastfeeding, p = 0.001). The mean VASs (SD) were 6.59 (1.82), 8.33 (1.58), 7.32 (1.66), and 6.95 (1.90) (before pregnancy vs. pregnancy, p < 0.001; during pregnancy vs. breastfeeding, p = 0.016), respectively. Among those who received a HAE diagnosis after pregnancy (n = 54), the number (59.3%) and the severity (60%) of HAE attacks were high in pregnancy. 47 of the deliveries were normal vaginal delivery (NVD). Regional anesthesia was applied in 8 NVDs. 20 of caesarean deliveries were performed under general anesthesia, and 21 were under spinal anesthesia. Lowest numbers of attacks were found in patients who did not receive anesthesia during NVD (p = 0.001). CONCLUSION: The course of HAE can be worse during pregnancy and breastfeeding. NVD is related to fewer HAE attacks and prophylaxis with C1-INH during NVD is not necessary to prevent a HAE attack.

Evolution of Guidelines for the Management of Hereditary Angioedema due to C1 Inhibitor Deficiency.

Hereditary angioedema (HAE) is a severe and disabling condition characterized by recurrent episodes of subcutaneous or mucosal swelling in the skin and respiratory and gastrointestinal tracts. HAE due to C1-esterase inhibitor deficiency (C1-INH-HAE) is the most prevalent subtype. The present Iberian study compared C1-INH-HAE treatment guidelines published between 2010 and 2022 to identify the main differences in therapeutic approaches for on-demand treatment and short- and long-term prophylaxis (LTP). HAE guidelines evolved with the availability of new treatments and with a change in the management paradigm towards an individualized, patient-centered approach, where quality of life (QOL) is central. A parallel trend was observed towards increasingly frequent home-based treatment, which potentially facilitates timely interventions, provides greater flexibility and convenience, and is associated with increased QOL, enabling patients to lead more normal lives. Most innovations over the years were made for LTP, together with the advent of new therapies and awareness of patients' needs. Several prophylactic therapies with a high level of evidence became available, although formal head-to-head comparisons are lacking. The treatment goals became more ambitious, ranging from a reduction in the frequency, severity, and duration of attacks to achieving total disease control and normalization of patients' lives. The document also addresses relevant items such as changes in terminology (eg, the introduction of designations as "first-line") and the introduction of patient-reported outcome measures to assess patients' perceptions of their self-experienced QOL and well-being. Unmet needs in the management of C1-INH-HAE are identified.

Expert Review and Consensus on the Treat-to-Target Management of Hereditary Angioedema: From Scientific Evidence to Clinical Practice.

BACKGROUND: Hereditary angioedema with C1 inhibitor deficiency (HAE-C1INH) is a rare disease characterized by swelling episodes. It affects quality of life (QOL) and can be fatal when the upper airways are involved. Treatment is individualized, with therapeutic options including on-demand treatment (ODT) and short- and long-term prophylaxis (STP, LTP). However, available guidelines are not always clear about the selection of treatment, the goals of treatment, or how achievement of these goals is assessed. OBJECTIVE: To review available evidence for the management of HAE-C1INH and build a Spanish expert consensus to steer management towards a treat-to-target approach, while addressing some of the less clear aspects of the Spanish guidelines. METHODS: We reviewed the literature on the treat-to-target management of HAE-C1INH, focusing on treatment selection and goals and the tools available to assess whether the goals have been achieved. We discussed the literature based on clinical experience and drew up 45 statements on undefined management aspects. A panel of 53 HAE experts validated the statements through a 2-round Delphi process. RESULTS: The goals for ODT and STP are to minimize the morbidity and mortality of attacks and to prevent attacks caused by known triggers, respectively, while the main goal of LTP is to decrease the rate, severity, and duration of attacks. Furthermore, when prescribing, clinicians should consider the reduction in adverse effects, while increasing patient QOL and satisfaction. Appropriate instruments for assessing achievement of treatment goals are also indicated. CONCLUSIONS: We provide recommendations on previously unclear aspects of HAE-C1INH management with ODT, STP, and LTP, focusing on clinical and patient-oriented goals.

Hereditary angioedema in cardiac surgery: Perioperative management considerations for a rare disease.

INTRODUCTION: Hereditary Angioedema is a rare disease caused by C1 esterase inhibitor deficiency leading to diffuse and potentially life-threatening oedema formation. Preventing attacks is critical, particularly for patients undergoing cardiac surgery. CASE REPORT: We report a case of a 71-years-old woman with a history of Hereditary Angioedema scheduled for open-heart surgery on Cardiopulmonary Bypass. Multidisciplinar teamwork and patient-targeted strategy were crucial to obtain a favorable outcome. DISCUSSION: Cardiac surgery is a major stressor for Angioedema attacks because of Complement cascade and inflammatory response activation leading to potential life-threatening oedema formation. In literature only few cases of complex open heart surgery under Cardiopulmonary Bypass are described. CONCLUSION: Continuous updating and multidisciplinarity are key elements to manage patients with Hereditary Angioedema in cardiac surgery in order to reduce morbidity and mortality.