One hypovolaemic shock…two kinin pathway abnormalities

Angioedèmes et médecine d’urgence

Les angioedèmes (AE) sont un motif de recours fréquent aux urgences. Leur morbimortalité n’est pas négligeable compte tenu de l’atteinte fréquente des voies aériennes supérieures. On distingue les AE histaminiques et bradykiniques. Aux urgences, la démarche diagnostique et la conduite à tenir doit être systématique et standardisée afin de ne pas méconnaître un potentiel AE bradykinique. Les AE histaminiques, accompagnés dans la plupart des cas d’une urticaire superficielle, sont de loin les plus fréquents et sont associés parfois à une anaphylaxie, ce qui nécessite alors un traitement par adrénaline immédiat. Ils peuvent être allergiques (médiés par les IgE) et sont alors associés à une anaphylaxie ou non allergiques, et se traduisent cliniquement par une urticaire aiguë ou chronique associée à l’AE. Les AE bradykiniques, d’incidence plus rare, sont également pourvoyeurs de recours aux urgences et particulièrement les AE secondaires aux inhibiteurs de l’enzyme de conversion de l’angiotensine compte tenu de leur importante prescription et de leurs atteintes cliniques de la face, de la langue et du larynx, elles-mêmes pourvoyeuses de recours aux urgences. Les traitements spécifiques d’urgence comprennent principalement l’icatibant et le concentré de C1-inhibiteur. Ils doivent être administrés le plus tôt possible devant l’inefficacité des traitements antiallergiques. Un avis auprès d’un expert du centre de référence pour les AE à kinines peut améliorer les prises en charge en aidant à la démarche diagnostique et en organisant la mise à disposition des traitements spécifiques d’urgence.

Hereditary angioedema, emergency management of attacks by a call center

OBJECTIVE

Hereditary angiœdema (HAE) is a rare autosomal dominant disease characterized by recurrent, unpredictable, potentially life-threatening swelling. Objective is to assess the management of the acute HAE attacks in the real life setting through a call center in France.

METHODS

A pre-specified ancillary study of SOS-HAE, a cluster-randomized prospective multicenter trial, was conducted. HAE patients were recruited from 8 participating reference centers. The outcome of interest was the rate of hospitalization.

RESULTS

onerhundred patients were included. The median (quartile) age was 38 (29-53) years, and 66 (66%) were female. Eighty (80%) patients had HAE type I, 8 (8%) had HAE type II and 12 (12%) patients had FXII-HAE. Fifty-one (51%) patients had experienced at least one time the call center during the follow-up. Nine over 166 (5%) attacks for 9 different patients resulted in hospital admission to the hospital (in the short-stay unit, ie, <24 h) during the follow-up period. During 2 years, there were 166 calls to call center for 166 attacks. All attacks were treated at home after call center contact.

CONCLUSIONS

Use of emergency departments and hospitalizations are reduced by the use of a coordinated national call center in HAE after therapeutic education program that promoted self-administration of specific treatment and use of call to call center.

TRIAL REGISTRATION

clinicalTrials.gov identifier: NCT01679912.

Specialist Advice Support for Management of Severe Hereditary Angioedema Attacks: A Multicenter Cluster-Randomized Controlled Trial

STUDY OBJECTIVE

Hereditary angioedema is a rare disease associated with unpredictable, recurrent attacks of potentially life-threatening edema. Management of severe attacks is currently suboptimal because emergency medical teams are often unaware of new specific treatments. The objective of this trial is to test whether a dedicated national telephone care-management strategy would reduce resource use during severe hereditary angioedema attacks.

METHODS

We conducted a cluster-randomized multicenter prospective trial of patients with a documented diagnosis of hereditary angioedema (type I, II or FXII hereditary angioedema). Participants were enrolled between March 2013 and June 2014 at 8 participating reference centers. The randomized units were the reference centers (clusters). Patients in the intervention arm were given a national free telephone number to call in the event of a severe attack. Emergency physicians in the SOS-hereditary angiœdema (SOS-HAE) call center were trained to advise or prescribe specific treatments. The primary outcome was number of admissions for angioedema attacks. Economic evaluation was also performed.

RESULTS

We included 100 patients in the SOS-HAE group and 100 in the control group. During the 2 years, there were 2,368 hereditary angioedema attacks among 169 patients (85%). Mean number of hospital admissions per patient in the 2-year period was significantly greater in the usual-practice group (mean 0.16 [range 0 to 2] versus 0.03 [range 0 to 1]); patient risk difference was significant: -0.13 (95% confidence interval -0.22 to -0.04; P=.02). Probabilistic sensitivity graphic analysis indicated a trend toward increased quality-adjusted life-years in the SOS-HAE group.

CONCLUSION

A national dedicated call center for management of severe hereditary angioedema attacks is associated with a decrease in hospital admissions and may be cost-effective if facilities and staff are available to deliver the intervention alongside existing services.

Dedicated call center (SOS-HAE) for hereditary angioedema attacks: study protocol for a randomised controlled trial

Background

Despite the availability of guidelines for the specific treatment of hereditary angioedema (HAE) attacks, HAE morbidity and mortality rates remain substantial. HAE attacks are a major medical issue requiring specific treatment as well as a considerable socio-economic burden. We report a protocol designed to test whether a dedicated call centre is more effective than usual practice in the management of patients experiencing an HAE attack.

Methods/design

This prospective, cluster-randomised, single-blind, parallel-group, multicentre trial evaluates the morbidity and consequent socio-economic costs of the management of patients experiencing an HAE attack by a dedicated call centre as compared to usual practice. The trial aims to recruit 200 patients. Patients in the intervention arm are provided with an SOS-HAE card with the call centre’s freephone number that they can access in the case of an attack. The centre’s mission is to provide recommended expert advice on early home treatment. The centre can route the call to a local emergency medical service with competency in HAE management or even arrange for the drugs needed for the specific treatment of an HAE attack to be sent to the emergency department of the local hospital. The primary outcome measure is the number of hospital admissions for an HAE attack. Each patient will be followed up every 2 months for 2 years. The study has been approved by the ethics committee (Comité de Protection des Personnes d’Ile de France 10; registration number: 2012-A00044-39; date of approval: 19 January 2012).

Discussion

The SOS-HAE protocol has been designed to address the handling of attacks experienced by patients with HAE in the home. The proposed trial will determine whether the setting up of a dedicated call centre is more effective than usual practice in terms of reducing morbidity as given by the numbers of hospital admissions. The results are also anticipated to have important implications in terms of socio-economic costs for both healthcare services and patients.

Trial registration

ClinicalTrials.gov NCT01679912.

[Hereditary angioedema biological diagnosis]

C1 inhibitor (C1 Inh) activity is an essential parameter for kinins angioedema (AE) diagnosis either hereditary or acquired or sporadic, it is analysed on plasma exclusively. Hereditary AE with C1 Inh functional deficiency is associated with alterations of the SERPING1 gene. Hereditary AE with normal C1 Inh (HAE nC1 Inh) is combined with F12 gene mutations, it is coding for Factor XII whose activity is controlled by C1 Inh, they are found in about 5% of HAE nC1 Inh cases. Every loss of C1 Inh activity must be taken as anormal by clinicians even for women with oral oestroprogestatives, it would be confirmed by the presence of cleaved C1 Inh. The kinins (primarily bradykinin) are the mediators responsible for local increase of vascular permeability. Bradykinin is released from high MW kininogen (HK) during the contact system activation. Plasma proteases mainly support this proteolytic activity controlled by C1 Inh. Family of a patient diagnosed with HAE must be studied, symptomatic as asymptomatic members indeed clinical symptoms regularly emerge very late in the life.

[Emergency management of bradykinin-mediated angioedema]

In the emergency setting, the diagnosis of bradykinin-mediated angioedema is based exclusively on history and physical examination. Severe attacks must be identified because the evolution is unpredictable with a risk of life-threatening airway obstruction. Underestimate the severity of the attack is a management pitfall to avoid. All attack under the shoulders should be considered as severe and must benefit from early specific treatment.

Hereditary angioedema: epidemiology, management, and role of icatibant

Hereditary angioedema (HAE) is an autosomal dominant, potentially life-threatening condition, manifesting as recurrent and self-limiting episodes of facial, laryngeal, genital, or peripheral swelling with abdominal pain secondary to intra-abdominal edema. The estimated prevalence of HAE in the general population is one individual per 50,000, with reported ranges from 1:10,000 to 1:150,000, without major sex or ethnic differences. Various treatment options for acute attacks and prophylaxis of HAE are authorized and available in the market, including plasma-derived (Berinert®, Cinryze®, and Cetor®) and recombinant (Rhucin® and Ruconest™) C1 inhibitors, kallikrein inhibitor-ecallantide (Kalbitor®), and bradykinin B2 receptor antagonist-icatibant (Firazyr®). Some of these drugs are used only to treat HAE attacks, whereas others are only approved for prophylactic therapies and all of them have improved disease outcomes due to their different mechanisms of action. Bradykinin and its binding to B2 receptor have been demonstrated to be responsible for most of the symptoms of HAE. Thus icatibant (Firazyr®), a bradykinin B2 receptor antagonist, has proven to be an effective and more targeted treatment option and has been approved for the treatment of acute attacks of HAE. Rapid and stable relief from symptoms of cutaneous, abdominal, or laryngeal HAE attacks has been demonstrated by 30 mg of icatibant in Phase III clinical trials. Self-resolving mild to moderate local site reactions after subcutaneous injection of icatibant were observed. Icatibant is a new, safe, and effective treatment for acute attacks of HAE. HAE has been reported to result in enormous humanistic burden to patients, affecting both physical and mental health, with a negative impact on education, career, and work productivity, and with substantial economic burdens. The timely and proper use of disease-specific treatments could improve patients’ quality of life, reduce the disease-specific morbidity and mortality, and, last but not least, reduce costs associated with hospitalizations and emergency room visits. Therefore, the paradigm of HAE treatment has the potential to evolve significantly, thereby exponentially improving a patient’s quality of life.

An evidence-based review of the potential role of icatibant in the treatment of acute attacks in hereditary angioedema type I and II

INTRODUCTION

Icatibant, a first-in-class B2 bradykinin receptor antagonist, appears to have a favorable efficacy and safety profile for the treatment of acute attacks of hereditary angioedema in adults.

AIMS

To update the evidence and provide an overview of the available data on icatibant.

EVIDENCE REVIEW

Peer reviewed articles published and listed in Medline Search and published updated guidelines for the treatment of acute attacks in hereditary angioedema type I and II in adults were reviewed. The validity and quality of evidence were evaluated.

PLACE IN THERAPY

Clinical evidence for the treatment of acute hereditary angioedema attacks with icatibant is strong. Approximately 10% of the patients require a second dose. No serious adverse reactions have been reported. The only significant side effects consistently registered by 90% of patients are transient local pain, swelling, and erythema at the local injection site.

CONCLUSION

Subcutaneously administered 30 mg icatibant has been shown to be a safe and efficacious treatment in clinical trials. It is the only specific treatment authorized for self-administration by the subcutaneous route offering increased patient independence.