Analysis of Heart-Rate Variability during Angioedema Attacks in Patients with Hereditary C1-Inhibitor Deficiency.

C1-inhibitor hereditary angioedema (C1-INH-HAE) is a rare disease characterized by self-limiting edema associated with localized vasodilation due to increased levels of circulating bradykinin. C1-INH-HAE directly influences patients' everyday lives, as attacks are unpredictable in frequency, severity, and the involved anatomical site. The autonomic nervous system could be involved in remission. The cardiac autonomic profile has not yet been evaluated during the attack or prodromal phases. In this study, a multiday continuous electrocardiogram was obtained in four C1-INH-HAE patients until attack occurrence. Power spectral heart rate variability (HRV) indices were computed over the 4 h preceding the attack and during the first 4 h of the attack in three patients. Increased vagal modulation of the sinus node was detected in the prodromal phase. This finding may reflect localized vasodilation mediated by the release of bradykinin. HRV analysis may furnish early markers of an impending angioedema attack, thereby helping to identify patients at higher risk of attack recurrence. In this perspective, it could assist in the timing, titration, and optimization of prophylactic therapy, and thus improve patients' quality of life.

Non-vitamin K oral anticoagulant use in the elderly: a prospective real-world study - data from the REGIstry of patients on Non-vitamin K oral Anticoagulants (REGINA).

PURPOSE: Numerous studies on thromboembolic prevention for non-valvular atrial fibrillation (NVAF) have shown either equal or better efficacy and safety of non-vitamin K oral anticoagulants (NOACs) compared to warfarin, even for patients aged ≥75 years. Data on elderly patients, in particular, octogenarians, are lacking. Paradoxically, this population is the one with the highest risk of bleeding and stroke with a worse prognosis. This study aims to describe safety and effectiveness of NOACs in an elderly comorbid population. PATIENTS AND METHODS: REGIstry of patients on Non-vitamin K oral Anticoagulants (REGINA) is a prospective observational study enrolling consecutive NVAF patients started on NOACs and followed up to 1 year (at 1, 6, 12 months). The primary endpoint was the incidence rate of major bleeding (MB) and clinically relevant non-major bleeding (CRNMB). The secondary endpoints were the incidence of 1) stroke or systemic embolism, 2) hospitalization, 3) death, and 4) drug-related adverse events. RESULTS: We enrolled 227 patients aged 81.6±6.1 years (range 67-95 years; ≥80 years in 59.4%). The median CHA2DS2-VASc was 5 (IQR 4-5) and HAS-BLED was 4 (IQR 3-5). The estimated glomerular filtration rate was 59.27±24.12 mL/min. During follow-up, only 10 MB and 23 CRNMB occurred, with a total incidence of 4.4% (95% CI: 1.7%-7.17%) and 5.7% (95% CI: 2.68%-8.72%), respectively. There were 2 cerebral ischemic events, with a total incidence of 0.88% (95% CI: 0.84%-0.92%), 23 NOAC-related hospitalizations, no NOAC-related deaths, and 4 minor drug-related adverse effects. CONCLUSION: In a population of aged and clinically complex patients, mainly octogenarians, NOACs were safe and effective.

Long-term follow-up of 111 patients with angiotensin-converting enzyme inhibitor-related angioedema.

OBJECTIVE: To investigate, for the first time, the frequency of recurrences of angiotensin-converting enzyme inhibitor (ACE-I)-related angioedema after the discontinuation of ACE-I. METHODS: This retrospective study was conducted in an outpatient tertiary-level centre for a total period of 173 months (about 14 years). Consecutive patients with recurrent angioedema symptoms, initiated during treatment with an ACE-I, who had been followed for at least 12 months after discontinuation of the drug were eligible. The primary study variable was the incidence of recurrences of angioedema after ACE-I discontinuation. Angioedema location, type of ACE-I and indication for this treatment and the drugs prescribed after the discontinuation of ACE-I were also evaluated. RESULTS: In total, 111 patients were followed; 54 of them (49%) were on enalapril. After discontinuation from ACE-I, 51 patients (46%) had further recurrences of angioedema; in 18 relapsers (16% of the total), the frequency of angioedema recurrences remained unchanged when compared with that reported during ACE-I treatment. The large majority of relapsers (88%) had the first recurrence of angioedema within the first month since ACE-I discontinuation. The switch to a different antihypertensive therapy did not seem associated with a reduction in the frequency of angioedema attacks. CONCLUSION: Even with all the limitations on any observational analysis, this long-term study suggests for the first time that patients with angioedema started while on ACE-I treatment seem to have a condition predisposing to angioedema that is elicited by the treatment with these drugs. Further studies in this field appear advocated due to the potential severity of angioedema attacks.

Mutation screening of C1 inhibitor gene in 108 unrelated families with hereditary angioedema: functional and structural correlates.

Hereditary angioedema (HAE) is an autosomal dominant disorder characterized by the deficiency of the inhibitor of the first component of complement system (C1-INH), which is due to mutations in its structural gene. There are two phenotypic variants: HAE type I, with reduced plasma antigen levels and HAE type II with normal antigen levels and reduced functional C1 inhibitor activity. The aim of this study was to determine the disease-causing mutations in 108 unrelated HAE families, followed at a single center in Italy, and in 50 normal controls by a genetic screening strategy of the C1-INH gene (SERPIN1G). To detect small mutations we either used fluorescence assisted mismatch analysis, followed by sequencing, or direct sequencing. Patients negative for mutations at this screening were further analyzed by long-range PCR to detect the presence of large deletions or insertions. Overall we identified 81 different mutations possibly responsible for the disease in 102 families, in the remaining 6 families no mutation was detected except for a synonymous substitution in a single probant. Sixty-seven of these mutations (23 missense, 22 frameshift, 8 splicing defects, 8 nonsense and 6 large insertion/deletions) had not been previously published. In addition, 4 rare variants, 2 synonymous alterations and 1 new polymorphism in the 3'UTR of the C1-INH gene were found. Mutations were distributed over all exons, at splice sites and in introns. Our study identified a large number of new mutations related to HAE providing additional evidence of the genetic heterogeneity of this disease. Our results also point toward particular amino acid residues important for protein function that may represent mutation hot spots.

Functional C1-inhibitor diagnostics in hereditary angioedema: assay evaluation and recommendations.

Hereditary angioedema (HAE) is an autosomal dominant disease characterized by recurrent episodes of potentially life-threatening angioedema. The most widespread underlying genetic deficiency is a heterozygous deficiency of the serine protease inhibitor C1 esterase inhibitor (C1-Inh). In addition to low C4 levels, the most important laboratory parameter for correct diagnosis of HAE or angioedema due to acquired C1-Inh deficiency is reduced C1-Inh function (fC1-Inh). No direct recommendations about the assays for fC1-Inh or sample handling conditions are available, although this would prove especially useful when a laboratory first starts to offer assays on fC1-Inh for HAE diagnosis. In the present study we evaluated the performance of fC1-Inh assays in the 15 different laboratories that are specialised in HAE diagnostics and assessed inter-laboratory variation with each laboratory using their own assays and standards. A double-blind survey was conducted using plasma/serum samples from healthy donors and HAE patients and the uniformity of HAE diagnosis was evaluated. It can be concluded that the diagnosis of fC1-Inh deficiency was made correctly in most cases in this survey. We can recommend the chromogenic assay for the determination of fC1-Inh, while the complex ELISA needs further investigation.

Successful resolution of bowel obstruction in a patient with hereditary angioedema.

Hereditary angioedema (HAE), a rare genetic disorder caused by a deficiency of the C1 esterase inhibitor, leads to an episodic, self-limiting increase in vascular permeability. Related symptoms commonly include recurrent, intractable abdominal pain, vomiting, and/or diarrhea. DX-88 (ecallantide), a 60-amino acid recombinant protein discovered through phage display technology, is a highly specific, potent inhibitor of human plasma kallikrein that has been used successfully in the treatment of patients experiencing acute HAE attacks. This case study involves a 65-year-old woman who presented with severe abdominal pain, cramping, and nausea. The study describes the use of a video obtained by capsule endoscopy for the direct imaging of bowel occlusion in a patient with HAE that resolved upon treatment with DX-88. After administration of DX-88, 80 mg intravenously, abdominal pain and nausea resolved within 30 min. Capsule endoscopy demonstrated a coincident resolution of the bowel wall edema, with a return to normal within approximately 1.5 h of DX-88 administration. This case study demonstrates that DX-88 can produce dramatic clinical benefits in a patient with an acute abdominal HAE attack, resolving both symptoms and pathologic signs. Furthermore, it illustrates the usefulness of videos obtained from capsule endoscopy in identifying the presence of bowel occlusion and demonstrating its subsequent rapid resolution upon administration of DX-88.

Hereditary angiodema: a current state-of-the-art review, VII: Canadian Hungarian 2007 International Consensus Algorithm for the Diagnosis, Therapy, and Management of Hereditary Angioedema.

BACKGROUND: We published the Canadian 2003 International Consensus Algorithm for the Diagnosis, Therapy, and Management of Hereditary Angioedema (HAE; C1 inhibitor [C1-INH] deficiency) in 2004. OBJECTIVE: To ensure that this consensus remains current. METHODS: In collaboration with the Canadian Network of Rare Blood Disorder Organizations, we held the second Canadian Consensus discussion with our international colleagues in Toronto, Ontario, on February 3, 2006, and reviewed its content at the Fifth C1 Inhibitor Deficiency Workshop in Budapest on June 2, 2007. Papers were presented by international investigators, and this consensus algorithm approach resulted. RESULTS: This consensus algorithm outlines the approach recommended for the diagnosis, therapy, and management of HAE, which was agreed on by the authors of this report. This document is only a consensus algorithm approach and continues to require validation. As such, participants agreed to make this a living 2007 algorithm, a work in progress, and to review its content at future international HAE meetings. CONCLUSIONS: There is a paucity of double-blind, placebo-controlled trials on the treatment of HAE, making levels of evidence to support the algorithm less than optimal. Controlled trials currently under way will provide further insight into the management of HAE. As with our Canadian 2003 Consensus, this 2007 International Consensus Algorithm for the Diagnosis, Therapy, and Management of HAE was formed through the meeting and agreement of patient care professionals along with patient group representatives and individual patients.

The use of plasma-derived C1 inhibitor in the treatment of hereditary angioedema.

C1-inhibitor (C1-INH) deficiency is the genetic defect underlying hereditary angioedema (HAE). Subjects with HAE suffer from recurrent angioedema that may result in death when it affects the larynx, severe abdominal pain when it affects the gastrointestinal mucosa and disfiguration when it affects the skin. The use of plasma-derived C1-INH concentrates to revert angioedema in HAE patients started in the 1970s. Since that time, three different preparations arrived onto the market, two of them are still present. Controlled studies and a large clinical experience indicate that C1-INH concentrate should be considered the treatment of choice for disabling angioedema attacks at any site. Efficacy has also been shown in preventing angioedema induced by invasive medical manoeuvres. Limited experience with repeated weekly infusions indicates that C1-INH can be used for long-term prophylaxis in selected patients. The safety profile is excellent and there are no reports of transmission of viral infections with the preparations available at present. C1-INH is licensed only in a limited number of countries. Clinical trials are ongoing at present to expand registration.

Established and new treatments for hereditary angioedema: An update.

Hereditary angioedema (HAE) is due to inherited deficiency of C1-inhibitor (C1-INH) and causes localized swelling that may be life-threatening when it affects the larynx. Replacement therapy with plasma derived C1-INH has been the principal life saving treatment for more than 20 years in several European countries. Nevertheless, it is not licensed in U.S. and even in Europe it is mostly supplied on a named patient basis. In the last 5 years, controlled clinical trials with four products (plasma derived C1-INH, the enzyme inhibitor Dx-88, the receptor antagonist Icatibant and a recombinant form of human C1-INH) have been performed or initiated in order to demonstrate their efficacy in reverting symptoms of HAE. Here we review the characteristics of these products and the current situation of the trials.

The deficiency of C1 inhibitor and its treatment.

In this article, we review the traditional therapies of hereditary angioedema (HAE) that have been used for several years. Some of these therapies were proposed before the definition of the underlying defect and the understanding of the pathogenesis of the disease. We also describe new compounds under investigation at present as potential therapies for HAE. Two of these new therapies (a plasma-kallikrein inhibitor and a bradykinin B(2)-receptor antagonist) have been developed based on the understanding that the pathogenesis of symptoms was mainly due to kallikrein activation and bradykinin release.

Lymphoproliferative disease and acquired C1 inhibitor deficiency.

Angioedema due to acquired deficiency of the C1-inhibitor is a bridging condition between autoimmunity and lymphoproliferation. We report 32 patients with acquired C1 inhibitor deficiency: 23 have anti C1-inhibitor autoantibodies; 13 have monoclonal gammopathies of unknown significance and 9 have non-Hodgkin's lymphoma. Our series suggest that different forms of B cell disorders coexist and/or evolve into each other in acquired angioedema.

Acquired deficiency of the inhibitor of the first complement component: presentation, diagnosis, course, and conventional management.

Acquired deficiency of the inhibitor of the first complement component (C1-INH) is a rare, potentially life-threatening disease whose cause, course, and management are not completely defined. This article analyzes the etiopathogenetic mechanism, the clinical presentation, and the relationship between acquired C1-INH deficiency and lymphoproliferative disorders. Moreover, the authors give an overview of the outcome of the disease and the different therapies proposed to cure it.

Angioedema without urticaria: a large clinical survey.

BACKGROUND: Angioedema without major urticarial flares (hives) is poorly understood. Its causes are diverse, and little is known about its pathogenic mechanisms. We report on our 11 years of experience with this condition and propose a classification of patients affected by angioedema unaccompanied by urticaria. METHODS: From 1993 through 2003 at our outpatient clinic, 929 consecutive patients were examined for recurrent angioedema unaccompanied by urticaria. A detailed history was taken to identify known causes of angioedema, with special attention to external allergenic agents. Each patient underwent a complete physical examination, routine laboratory tests (blood cell count, protein electrophoresis, erythrosedimentation rate, examination of stool for ova and parasites, pharyngeal and urine cultures, sinus and dental radiography, and measurements of antitissue autoantibodies and rheumatoid factor in plasma), and complement parameters (C1 inhibitor, C4 and C1q). Further testing was done when pertinent, based on clinical findings. When all results were negative, response to H1-antihistamine was considered. RESULTS: Angioedema could not be classified in 153 patients who were lost to follow-up (16.4%). Among the 776 cases with adequate data, these types of angioedema were identified: 124 (16%) related to external agents such as a drug, insect bite or foodstuff; 85 (11%) related to treatment with angiotensin-converting enzyme inhibitor; 55 (7%) associated with an autoimmune disease or infection; and 197 (25%) caused by C1 inhibitor deficiency. In the other 315 cases (41%), the etiology was undiscovered: 254 cases (33% of the study sample) were idiopathic histaminergic; 40 (5%) were idiopathic nonhistaminergic; and 21 (3%) had other causes of peripheral or generalyzed edema. INTERPRETATION: Our data indicated that angioedema without urticaria could be classified according to specific clinical and pathogenic characteristics, and we have suggested a work-up for patients experiencing this condition.

Angiotensin-converting enzyme inhibitor-related angioedema: how to deal with it.

Angiotensin-converting enzyme inhibitor-related angioedema is a well documented condition, which seems to occur in up to 1% of treated patients. It represents a problem for both the clinician and the patient: for the clinician, the diagnosis may be difficult due to its peculiar clinical characteristics, whereas for the misdiagnosed patient the delay prolongs a potentially dangerous situation. If the drug is not discontinued, the attacks tend to become worse and even life-threatening. There are now evidences that increased levels of bradykinin have an important role in the pathophysiology of attacks and, moreover, there are genetic factors that render certain individuals susceptible to angiotensin-converting enzyme inhibitor-related angioedema. In this review, the authors analyse the pathogenetic mechanism, the clinical presentation, the management and future perspectives of research on this condition.

C1 inhibitor: molecular and clinical aspects.

C1 inhibitor (C1-INH) is a serine protease inhibitor (serpins) that inactivates several different proteases in the complement, contact, coagulation, and fibrinolytic systems. By its C-terminal part (serpin domain), characterized by three beta-sheets and an exposed mobile reactive loop, C1-INH binds, and blocks the activity of its target proteases. The N-terminal end (nonserpin domain) confers to C1-INH the capacity to bind lipopolysaccharides and E-selectin. Owing to this moiety, C1-INH intervenes in regulation of the inflammatory reaction. The heterozygous deficiency of C1-INH results in hereditary angioedema (HAE). The clinical picture of HAE is characterized by bouts of local increase in vascular permeability. Depending on the affected site, patients suffer from disfiguring subcutaneous edema, abdominal pain, vomiting and/or diarrhoea for edema of the gastrointestinal mucosa, dysphagia, and dysphonia up to asphyxia for edema of the pharynx and larynx. Apart from its genetic deficiency, there are several pathological conditions such as ischemia-reperfusion, septic shock, capillary leak syndrome, and pancreatitis, in which C1-INH has been reported to either play a pathogenic role or be a potential therapeutic tool. These potential applications were identified long ago, but controlled studies have not been performed to confirm pilot experiences. Recombinant C1-INH, produced in transgenic animals, has recently been produced for treatment of HAE, and clinical trials are in progress. We can expect that the introduction of this new product, along with the existing plasma derivative, will renew interest in exploiting C1-INH as a therapeutic agent.

Canadian 2003 International Consensus Algorithm For the Diagnosis, Therapy, and Management of Hereditary Angioedema.

C1 inhibitor deficiency (hereditary angioedema [HAE]) is a rare disorder for which there is a lack of consensus concerning diagnosis, therapy, and management, particularly in Canada. European initiatives have driven the approach to managing HAE with 3 C1-INH Deficiency Workshops held every 2 years in Hungary starting in 1999, with the third Workshop having recently been held in May 2003. The European Contact Board has established a European HAE Registry that will hopefully advance our knowledge of this disorder. The Canadian Hereditary Angioedema Society/Société d'Angioédème Héréditaire du Canada organized a Canadian International Consensus Conference held in Toronto, Ontario, Canada, on October 24 to 26, 2003, to foster consensus between major European and North American HAE treatment centers. Papers were presented by investigators from Europe and North America, and this consensus algorithm approach was discussed. There is a paucity of double-blind placebo-controlled trials in the treatment of HAE, making levels of evidence to support the algorithm less than optimal. Enclosed is the consensus algorithm approach recommended for the diagnosis, therapy, and management of HAE and agreed to by the authors of this article. This document is only a consensus algorithm approach and requires validation. As such, participants agreed to make this a living 2003 algorithm (ie, a work in progress) and agreed to review its content at future international HAE meetings. The consensus, however, has strength in that it was arrived at by the meeting of patient-care providers along with patient group representatives and individual patients reviewing information available to date and reaching agreement on how to approach the diagnosis, therapy, and management of HAE circa 2003. Hopefully evidence to support approaches to the management of HAE will approach the level of meta-analysis of randomized controlled trials in the near future.

C1 inhibitor gene expression in patients with hereditary angioedema: quantitative evaluation by means of real-time RT-PCR.

BACKGROUND: Hereditary angioedema (HAE) is caused by heterozygous defects in the C1 inhibitor (C1-INH) gene (SERPING1/C1NH). In patients' plasma C1-INH levels range between 5% and 30% of normal levels (ie, far from the 50% expected for an autosomal dominant defect). Most patients have antigenic and functional deficiency (type I HAE), and 15% have reduced C1-INH function but normal to increased antigen because of the presence of a dysfunctional protein (type II HAE). OBJECTIVE: We sought to contribute to the understanding of the pattern of C1-INH gene expression in patients with HAE. METHODS: We used real-time quantitative RT-PCR to measure C1-INH mRNA levels in PBMCs of 57 patients with HAE typed for mutations in the SERPING1/C1NH gene. RESULTS: Thirty-six different mutations were identified in genomic DNA. Compared with healthy control subjects, C1-INH mRNA was significantly and similarly reduced in patients with type I and type II HAE (40% and 47%, respectively; P <.0001). By means of direct sequencing of cDNAs, we found that 74% of patients with type I HAE carrying small mutations presented significant amounts of mutated transcripts at the mRNA level, suggesting that both allelic mRNA products were reduced to approximately 50%. In 4 patients carrying large deletions expected to fully inactivate expression from the mutant allele, C1-INH mRNA was 23% on average compared with that seen in control subjects, confirming that normal mRNA was strongly underexpressed. CONCLUSIONS: These new findings, combined with previous evidence of increased C1-INH consumption, might explain the plasma levels of normal C1-INH that are markedly less than the expected 50%.

Angioedema associated with angiotensin-converting enzyme inhibitor use: outcome after switching to a different treatment.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors are associated with angioedema episodes that are potentially life-threatening. Few data are available on the outcome of patients reporting this adverse effect when they are switched to another drug. Scattered reports of angioedema associated with angiotensin II receptor blocker (ARB) use question the safety of using these drugs in patients with ACE inhibitor-related angioedema. We describe 64 consecutive patients with ACE inhibitor-related angioedema, the outcome after discontinuing this treatment, and the safety of using ARBs. METHODS: Retrospective analysis of 64 consecutive patients (January 1993 to June 2002) presenting with angioedema onset while receiving treatment with an ACE inhibitor. RESULTS: Patients were recommended to stop ACE inhibitor use, substituting it upon advice of the physician. Fifty-four patients were available for follow-up (median follow-up, 11 months; range, 1-80 months): 26 had switched to an ARB, 14 to a calcium antagonist, and 14 to other antihypertensive drugs. Angioedema disappeared or drastically reduced upon withdrawal of the ACE inhibitor in 46 patients (85%). For the remaining 8 patients, angioedema was due to a cause other than ACE inhibitor use in 2; angioedema persisted independent of the treatment and without apparent cause (idiopathic angioedema) in 4; angioedema persisted after switching to an ARB and disappeared upon its withdrawal in 2. CONCLUSIONS: Stopping ACE inhibitor use without further assessments is a successful measure in the large majority of patients developing angioedema while taking this drug. Only a small percentage of patients with ACE inhibitor-related angioedema continue with this symptom when switched to an ARB.

How do we treat patients with hereditary angioedema.

Hereditary angioedema (HAE) is due to the inherited deficiency of C1-Inhibitor (C1-Inh). When specific treatment was not available, the mortality rate for this disease was as high as 50% and the disability up to 100-150 days per year (Agostoni and Cicardi, Hereditary and acquired C1-inhibitor deficiency: biological and clinical characteristics in 235 patients). Such a worrying scenario dramatically improves upon appropriate treatment. Nevertheless, the disease still frequently goes undiagnosed or misdiagnosed as an allergic condition. Both circumstances prevent patients from receiving drugs that could save and/or improve the quality of their life. The interest of our group for patients with HAE goes back to the early seventies. Since that time, 441 such patients have been examined and treated at our department; 403 are still actively followed. Here we present our experience on the treatment of HAE.

Autoantibodies and lymphoproliferative diseases in acquired C1-inhibitor deficiencies.

Angioedema due to acquired C1-inhibitor (C1-INH) deficiency (also referred to as "acquired angioedema") is a rare, life-threatening disease with poorly defined etiology, therapy, and prognosis. To define the profile of acquired C1-INH deficiency and to facilitate the clinical approach to these patients, we report on 23 patients with acquired C1-INH deficiency followed for up to 24 years (median, 8 yr), and review the literature. We measured C1-INH activity with chromogenic assay and detected autoantibodies to C1-INH by enzyme-linked immunosorbent assay (ELISA). Median age at onset of angioedema was 57 years (range, 39-75 yr). All patients had C1-INH function and C4 antigen below 50% of normal. C1q was reduced in 17 patients. Autoantibodies to C1-INH were present in 17 patients. Long-term prophylaxis of attacks with danazol was effective in 2 of 6 patients, and with tranexamic acid, in 12 of 13 patients. Therapy with C1-INH plasma concentrate was necessary in 12 patients: 9 had rapid positive response and 3 became progressively resistant. Associated diseases at the last follow-up were non-Hodgkin lymphomas (3 patients), chronic lymphocytic leukemia (1 patient), breast cancer (1 patient), monoclonal gammopathies of uncertain significance (13 patients). In 4 patients no pathologic condition could be demonstrated. Compared with the general population, patients with acquired C1-INH deficiency present higher risk for B-cell malignancies, but not for progression of monoclonal gammopathies of uncertain significance to malignancy. Antifibrinolytic agents are more effective than attenuated androgens in long-term prophylaxis. Patients with acquired C1-INH deficiency may be resistant to replacement therapy with C1-INH plasma concentrate.