Normalization of C1 Inhibitor in a Patient with Hereditary Angioedema.

Hereditary angioedema is a potentially life-threatening autosomal dominant condition, causing attacks of angioedema due to failure to regulate bradykinin. Nearly all cases of hereditary angioedema are caused by mutations in the gene encoding C1 inhibitor, SERPING1. C1 inhibitor is a multifunctional protein produced in the liver that regulates the kallikrein-kinin system at multiple points. An infant with genetically confirmed hereditary angioedema and low C1 inhibitor levels (but without previous episodes of angioedema) underwent liver transplantation for biliary atresia, an unrelated condition. Liver transplantation led to normalization of the C1 inhibitor level and function. To our knowledge, this represents the first patient to be potentially cured of hereditary angioedema.

Physician- and patient-reported outcomes by hereditary angioedema type: Data from a real-world study.

Background: Hereditary angioedema (HAE) is a rare genetic condition characterized by painful and often debilitating swelling attacks. Little is known about the differences in outcomes between patients with HAE types I or II (type I: HAE caused by C1 esterase inhibitor deficiency; type II: HAE caused by C1 esterase inhibitor dysfunction), with decreased or dysfunctional C1 esterase inhibitor (C1-INH), and those with normal C1-INH (nC1-INH-HAE). Objective: To compare physician- and patient-reported real-world outcomes in patients with HAE types I/II versus patients with nC1-INH-HAE. Methods: Data were drawn from the Adelphi HAE Disease Specific ProgrammeTM a real-world, cross-sectional survey of HAE-treating physicians and their patients in the United States conducted between July and November 2021. Physicians reported patient disease activity and severity, and recent attack history. Patient-reported outcomes were collected. Bivariate tests used were either the Student's t-test, the Fisher exact test, or Mann-Whitney U test. Results: Physicians (N = 67) provided data on 368 patients (92.4% HAE types I/II and 7.6% nC1-INH-HAE). Physicians reported that a higher proportion of patients with nC1-INH-HAE had moderate or high disease activity and moderate or severe disease severity both at diagnosis and at data collection versus those with HAE types I/II. Patients with nC1-INH-HAE versus patients with HAE types I/II experienced increased attack severity (34.6% versus 4.4%) and hospitalization rate during the most recent attack (39.3% versus 6.6%), and reported lower health status and quality of life, via the European Quality of Life 5 Dimension 5 Level (US tariff) and Angioedema Quality of Life, respectively. On average, 25% of the patients with nC1-INH-HAE reported absenteeism and work or activity impairment due to HAE compared with 2.7% of patients with HAE types I/II. Both patient groups reported improvements in disease activity and severity from diagnosis to the time of data collection. Conclusion: These real-world findings suggest that patients with nC1-INH-HAE have increased disease activity and severity, and experience greater impairment to their quality of life, work, and daily functioning than patients with HAE types I/II. Powered statistical analyses are required to confirm these findings.

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.

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.

Flow-mediated vasodilation assay indicates no endothelial dysfunction in hereditary angioedema patients with C1-inhibitor deficiency.

BACKGROUND: Hereditary angioedema with C1 inhibitor deficiency (C1-INH-HAE) is a rare, potentially life-threatening disorder characterized by recurrent edematous attacks. The edema formation is the consequence of interaction of bradykinin and various vasoactive peptides with endothelium. Besides these agents, danazol, a modified testosterone derivative used in these patients to prevent edematous attacks, can also affect the function of the endothelium, because it shifts the blood lipid profile to a pro-atherogenic phenotype. OBJECTIVE: To assess the endothelial function in C1-INH-HAE patients and in healthy matched controls. METHODS: To evaluate the endothelial function, we used the flow-mediated dilation method measured in the region of the brachial artery in 33 C1-INH-HAE patients and in 30 healthy matched controls. Laboratory measurements of standard biochemical parameters were performed on computerized laboratory analyzers. RESULTS: No difference was found in endothelial function (reactive hyperemia, RH) between patients (median, 9.0; 25%-75% percentile, 6.3-12.9) and controls (median, 7.37; 25%-75% percentile, 4.52-9.93). Although we found elevated cardiovascular risk (high body mass index and low-density lipoprotein/high-density lipoprotein ratio) in danazol-treated C1-INH-HAE patients, RH values did not differ between danazol-treated and nontreated patients. Furthermore, risk factors correlated with the endothelial function only in healthy controls and patients not treated with danazol. CONCLUSION: In summary, our results did not indicate any signs of endothelial dysfunction in C1-INH-HAE patients. Moreover, the normal endothelial function in danazol-treated patients with pro-atherogenic lipid profile suggests that elevated bradykinin level or other factor(s) involved in the pathogenesis of edematous attacks may have a protective role against endothelial dysfunction and atherosclerosis.

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

BACKGROUND: The consensus documents published to date on hereditary angioedema with C1 inhibitor deficiency (C1-INH-HAE) have focused on adult patients. Many of the previous recommendations have not been adapted to pediatric patients. We intended to produce consensus recommendations for the diagnosis and management of pediatric patients with C1-INH-HAE. METHODS: During an expert panel meeting that took place during the 9th C1 Inhibitor Deficiency Workshop in Budapest, 2015 (www.haenet.hu), pediatric data were presented and discussed and a consensus was developed by voting. RESULTS: The symptoms of C1-INH-HAE often present in childhood. Differential diagnosis can be difficult as abdominal pain is common in pediatric C1-INH-HAE, but also commonly occurs in the general pediatric population. The early onset of symptoms may predict a more severe subsequent course of the disease. Before the age of 1 year, C1-INH levels may be lower than in adults; therefore, it is advisable to confirm the diagnosis after the age of one year. All neonates/infants with an affected C1-INH-HAE family member should be screened for C1-INH deficiency. Pediatric patients should always carry a C1-INH-HAE information card and medicine for emergency use. The regulatory approval status of the drugs for prophylaxis and for acute treatment is different in each country. Plasma-derived C1-INH, recombinant C1-INH, and ecallantide are the only agents licensed for the acute treatment of pediatric patients. Clinical trials are underway with additional drugs. It is recommended to follow up patients in an HAE comprehensive care center. CONCLUSIONS: The pediatric-focused international consensus for the diagnosis and management of C1-INH-HAE patients was created.

Endocan: A Novel Marker of Endothelial Dysfunction in C1-Inhibitor-Deficient Hereditary Angioedema.

BACKGROUND: Hereditary angioedema (HAE) related to C1-inhibitor deficiency is a rare autosomal dominant disorder. Vascular cell adhesion molecules (VCAM) are known as endothelial activation markers. Endocan (also called ESM-1) is proposed as an endothelial dysfunction indicator. We aimed to investigate endothelial activation in attack-free periods in HAE patients by measuring their levels of endocan and VCAM-1. METHODS: Twenty-six HAE patients (22 female, mean age 40 ± 13 years) and 38 healthy control patients (13 female, mean age 36.9 ± 12 years) were included in the study. Peripheral blood samples were collected from HAE patients during symptom-free periods and control subjects. Endocan and VCAM-1 levels were measured using the enzyme-linked immunosorbent assay method. RESULTS: The median serum levels of endocan (647 ± 101 ng/mL) and VCAM-1 (500 ± 79 ng/mL) in the HAE patients were significantly higher than in the control patients (391 ± 41 and 325 ± 4; p < 0.001 for both). CONCLUSION: The increased endocan and VCAM-1 levels may reflect an endothelial activation even in attack-free periods in HAE patients.

Patient satisfaction and experience with intravenously administered C1-inhibitor concentrates in the United States.

BACKGROUND: Hereditary angioedema (HAE) is a rare genetic disorder with substantial morbidity and mortality. Despite expanded choices for effective acute treatment, prophylactic options are more limited. Intravenous C1 esterase inhibitor (C1-INH[IV]) is licensed and used to prevent HAE symptoms. OBJECTIVE: To better understand patient experiences with using C1-INH(IV), including level of satisfaction and types and frequency of complications. METHODS: Fifty adult members (≥18 years of age) of the US HAE Association who had HAE type I or II completed a self-administered internet survey. Eligible participants were experiencing at least 1 HAE attack per month and must have been receiving treatment with C1-INH(IV) as prophylaxis or acute therapy. RESULTS: Almost all respondents (n = 47; 94%) were using C1-INH(IV) for HAE prophylaxis. Most patients reported administration of C1-INH(IV) through a peripheral vein (n = 34) and 19 were currently (n = 17) or previously (n = 2) using a central venous port. Most respondents (62%) who used a peripheral vein to administer treatment reported having difficulty finding a usable vein or getting the infusion to work properly at least some of the time. Issues accessing veins, exhausted veins, and frequency of attacks were the main reasons physicians recommended ports to respondents. Although ports allow easier administration of therapy, 47% of respondents with ports experienced problems such as occlusion, thrombosis, and infection. Respondents using C1-INH prophylaxis reported a mean of 2.3 attacks per month during the previous 6 months. CONCLUSION: The survey results identified clinical challenges with IV HAE medication use, including venous access issues and ongoing monthly attack occurrence despite prophylactic C1-INH(IV) administration.

Anabolic androgen use in the management of hereditary angioedema: Not so cheap after all.

BACKGROUND: Hereditary angioedema due to C1 inhibitor deficiency (HAE) is a rare, life-threatening disease that imposes a significant burden on affected patients. 17α-alkylated androgens (anabolic androgens) decrease attack frequency and severity but carry the risk of potentially serious dose-related adverse effects. Despite the emergence of targeted therapies for HAE, continued anabolic androgen use has been driven in part by their low cost. OBJECTIVE: To examine the hidden cost of anabolic androgen use related to the risk of developing non-HAE comorbidities. METHODS: Patients with HAE were identified in the Southern California Kaiser Permanente database using clinical and laboratory findings compatible with HAE. These patients were stratified into anabolic androgen exposed and nonexposed groups. Matched controls were selected from the Kaiser database who did not have HAE or anabolic androgen exposure. Using multivariate analysis, we determined the number of non-HAE comorbidities linked to anabolic androgen use. We next determined the association between dosing and increasing exposure to anabolic androgens and the likelihood of having various comorbidities. RESULTS: Patients with HAE exposed to anabolic androgens had a 28% increase (P = .04) in non-HAE comorbidities when compared with their matched (nonexposed) controls. With each gram per month increase in exposure, a 12% increase in non-HAE comorbidities is observed (P < .01). The most commonly occurring non-HAE comorbidities were psychiatric, muscle cramps, obesity, and hyperlipidemia. CONCLUSION: Our data suggest that long-term anabolic androgen use enhances the risk of developing comorbid health conditions, thus amplifying the cost of care. Our report provides additional support for the preferred use of newer, targeted therapies for the management of HAE.

Novel Vasoregulatory Aspects of Hereditary Angioedema: the Role of Arginine Vasopressin, Adrenomedullin and Endothelin-1.

The elevation of bradykinin (BK) level during attacks of hereditary angioedema due to C1-Inhibitor deficiency (C1-INH-HAE) is well known. We previously demonstrated that endothelin-1 (ET-1) level also increases during C1-INH-HAE attacks. Although BK and ET-1 are both potent vasoactive peptides, the vasoregulatory aspect of the pathomechanism of C1-INH-HAE has not yet been investigated. Hence we studied the levels of vasoactive peptides in controls and in C1-INH-HAE patients, as well as evaluated their changes during C1-INH-HAE attacks. The levels of arginine vasopressin (AVP), adrenomedullin (ADM) and ET-1 were measured in the plasma of 100 C1-INH-HAE patients in inter-attack periods and of 111 control subjects, using BRAHMS Kryptor technologies. In 18 of the 100 C1-INH-HAE patients, the levels of vasoactive peptides were compared in blood samples obtained during attacks, or in inter-attack periods. AVP, ADM and ET-1 levels were similar in inter-attack samples from C1-INH-HAE patients and in the samples of controls, although cardiovascular risk has an effect on the levels of vasoactive peptides in both groups. The levels of all three vasoactive peptides increased during C1-INH-HAE attacks. Moreover, the levels of ET-1 and ADM as well as their changes during attacks were significantly correlated. This study demonstrated that vascular regulation by vasoactive peptides is affected during C1-INH-HAE attacks. Our results suggest that the cooperation of several vasoactive peptides may be necessary to counterbalance the actions of excess BK, and to terminate the attacks. This may reveal a novel pathophysiological aspect of C1-INH-HAE.

Elevated plasma levels of vascular permeability factors in C1 inhibitor-deficient hereditary angioedema.

BACKGROUND: Hereditary angioedema with C1 inhibitor deficiency (C1-INH-HAE) is a rare inherited genetic disease characterized by recurrent swelling episodes of the skin, gastrointestinal tract, and upper airways. Angioedema attacks result from increased vascular permeability due to the release of bradykinin from high molecular weight kininogen. Currently, there are no biomarkers predicting the frequency of angioedema attacks. Vascular permeability is modulated by several factors, including vascular endothelial growth factors (VEGFs) and angiopoietins (Angs). As increased circulating levels of VEGFs and Angs have been observed in diseases associated with higher vascular permeability (e.g., systemic capillary leak syndrome and sepsis), we sought to analyze plasma concentrations of VEGFs and Angs in patients with C1-INH-HAE. METHODS: Sixty-eight healthy controls and 128 patients with C1-INH-HAE were studied. Concentrations of angiogenic (VEGF-A, Ang1, Ang2), anti-angiogenic (VEGF-A165b ) and lymphangiogenic (VEGF-C) factors were evaluated by ELISA. C1-INH functional activity was assessed by EIA. RESULTS: Plasma concentrations of VEGF-A, VEGF-C, Ang1, and Ang2 were higher in patients with C1-INH-HAE in remission than in healthy controls. Concentration of VEGF-A was further increased in patients with lower C1-INH functional activity. Patients with C1-INH-HAE experiencing more than 12 angioedema attacks per year were characterized by higher plasma levels of VEGF-A, VEGF-C, and Ang2 compared with the other patients. CONCLUSIONS: We hypothesize that VEGFs and Angs induce a state of 'vascular preconditioning' that may predispose to angioedema attacks. In addition, the identification of increased plasma levels of VEGFs and Angs in patients with C1-INH-HAE may prompt the investigation of VEGFs and Angs as biomarkers of C1-INH-HAE severity.

Thyroid hormones and complement parameters in hereditary angioedema with C1-inhibitor deficiency.

BACKGROUND: Thyroid hormones control and up-regulate the synthesis of many plasma proteins. OBJECTIVE: To explore possible associations between thyroid hormone and complement levels in patients with hereditary angioedema resulting from the deficiency of the C1-inhibitor (C1-INH-HAE). METHODS: In this case-control study, serum thyrotropin, free triiodothyronine (FT3), and free thyroxine (FT4) levels, anti-thyroid peroxidase and antithyroglobulin antibody titers, and C1-INH concentrations were measured in 117 euthyroid patients with C1-INH-HAE and compared with their clinical properties. The control group comprised 150 healthy, age- and sex-matched, euthyroid individuals. RESULTS: The thyrotropin and antithyroglobulin levels were similar between the patients and the controls. Significantly lower FT3 (P < .001) and FT4 (P = .002) levels, as well as higher anti-thyroid peroxidase titers (P < .001), were seen in the patients with C1-INH-HAE. The proportion of patients with reduced C1-INH activity was greater among those with below-median FT4 levels than among those with above-median values (P = .02). Patients who experienced more edematous attacks per year had lower FT4 levels (within the normal range) than those afflicted by fewer episodes (P = .01). The FT3 and FT4 levels were significantly higher in patients undergoing long-term danazol therapy than in those who did not receive this drug (P = .01 and P = .02, respectively). The proportion of patients with FT4 levels in the below-median range was higher in the subset with increased d-dimer concentration (P = .009). CONCLUSION: Minor variations of the thyroid hormone levels (within the reference range) can influence the function of C1-INH in C1-INH-HAE. Our findings suggest a role for the endocrine system in the pathophysiology of C1-INH-HAE.

Hereditary angioedema: 44 years of diagnostic delay.

We report a 64-year-old man who suffered from recurrent visible swelling attacks since the age of 20 as well as episodes with severe upper airway edema, resulting in 4 emergency tracheotomies. Eventually after 44 years he was diagnosed with hereditary angioedema (HAE) type II. The aims of this report is to emphasize the importance of awareness concerning HAE, which does not respond to traditional anti-allergic therapy, and remind physicians to test for functional C1-INH deficiency.