Icatibant, an inhibitor of bradykinin receptor 2, for hereditary angioedema attacks: prospective experimental single-cohort study / Icatibanto, um inibidor de receptor 2 de bradicinina, para ataques de angioedema hereditário: estudo experimental prospectivo de coorte sem grupo controle

CONTEXT AND OBJECTIVE: Hereditary angioedema (HAE) with C1 inhibitor deficiency manifests as recurrent episodes of edema involving the skin, upper respiratory tract and gastrointestinal tract. It can be lethal due to asphyxia. The aim here was to evaluate the response to therapy for these attacks using icatibant, an inhibitor of the bradykinin receptor, which was recently introduced into Brazil. DESIGN AND SETTING: Prospective experimental single-cohort study on the efficacy and safety of icatibant for HAE patients. METHODS: Patients with a confirmed HAE diagnosis were enrolled according to symptoms and regardless of the time since onset of the attack. Icatibant was administered in accordance with the protocol that has been approved in Brazil. Symptom severity was assessed continuously and adverse events were monitored. RESULTS: 24 attacks in 20 HAE patients were treated (female/male 19:1; 19-55 years; median 29 years of age). The symptoms were: subcutaneous edema (22/24); abdominal pain (15/24) and upper airway obstruction (10/24). The time taken until onset of relief was: 5-10 minutes (5/24; 20.8%); 10-20 (5/24; 20.8%); 20-30 (8/24; 33.4%); 30-60 (5/24; 20.8%); and 2 hours (1/24; 4.3%). The time taken for complete resolution of symptoms ranged from 4.3 to 33.4 hours. Adverse effects were only reported at injection sites. Mild to moderate erythema and/or feelings of burning were reported by 15/24 patients, itching by 3 and no adverse effects in 6. CONCLUSION: HAE type I patients who received icatibant responded promptly; most achieved improved symptom severity within 30 minutes. Local adverse events occurred in 75% of the patients. .

CONTEXTO E OBJETIVO: O angioedema hereditário (AEH) com deficiência de inibidor de C1 manifesta-se por episódios recorrentes de edema envolvendo pele, trato respiratório superior e gastrointestinal. Pode ser letal por asfixia. O objetivo foi avaliar a resposta à terapia dos ataques com icatibanto, inibidor do receptor de bradicinina, recentemente introduzido no Brasil. TIPO DE ESTUDO E LOCAL: Estudo experimental prospectivo de coorte, sem grupo controle, da eficácia e segurança do icatibanto em paciente com AEH. MÉTODOS: Pacientes com diagnóstico confirmado de AEH foram incluídos de acordo com os sintomas, independentemente do tempo de início do ataque. Icatibanto foi administrado segundo protocolo aprovado no Brasil. A gravidade do sintoma foi estabelecida continuamente e os eventos adversos foram monitorados. RESULTADOS: 24 ataques em 20 pacientes com AEH foram tratados (19 F:1 M; 19-55 anos; mediana 29 anos). Os sintomas foram: edema subcutâneo (22/24), dor abdominal (15/24) e obstrução de vias aéreas superiores (10/24). O tempo para o início do alívio foi: 5-10 minutos, 5/24 (20,8%); 10-20, 5/24 (20,8%); 20-30, 8/24 (33,4%); 30-60, 5/24 (20,8%) e 2 horas, 1/24 (4,3%). O tempo para a resolução completa variou de 4,3-33,4 horas. Somente efeitos adversos nos locais das injeções foram relatados. Eritema leve a moderado e/ou sensação de ardor foram relatados por 15/24 pacientes, prurido em 3, e 6 não tiveram efeitos adversos. CONCLUSÃO: Pacientes com AEH tipo I receberam icatibanto com pronta resposta; a maioria teve melhora na gravidade dos sintomas em 30 minutos. Eventos adversos locais ocorreram em 75% dos pacientes. .

Angioedema hereditario: Tratamiento del ataque agudo en la Argentina / Hereditary angioedema: Treatment of acute attacks in Argentina

En el mundo, el angioedema hereditario (HAE) afecta a 1 de cada 50 000 personas. Produce episodios de angioedema cutáneo, abdominal y laríngeos que generan gran incapacidad. La mortalidad por la enfermedad oscila entre 15 y 50%. Aunque en Argentina un concentrado plasmático de C1 inhibidor (pdC1INH) ha estado aprobado y disponible por décadas para el tratamiento del ataque agudo, solo 15 (26%) de 58 pacientes había recibido pdC1INH alguna vez hasta el año 2008, y solo 2(3.4%) lo usaban regularmente. Luego de la aprobación de los nuevos medicamentos para HAE, incluido el icatibant en Argentina y de la publicación de las guías terapéuticas, 42 (82%) de 51 pacientes del grupo original tienen pdC1INH para tratar el próximo ataque. Sin embargo, 16 (18%) de estos pacientes continúan sin acceso a la medicación y otros 15 (35.7%) acceden a través de otro enfermo en forma espuria. Solo 12 (28.6%) de los pacientes con el medicamento puede auto tratarse en su domicilio. La mejora en el acceso a la medicación es importante pero debe extenderse a todos los afectados y facilitarse el auto-tratamiento.

In the world, hereditary angioedema (HAE) affects 1every 50 000 persons. It is characterized by highly disabling and recurrent episodes of cutaneous, abdominal and laryngeal episodes of angioedema. Asphyxia related mortality ranges from 15 to 50%. In Argentina a plasma derived C1 inhibitor concentrate (pdC1INH) has been available for the treatment of acute attacks for many decades, however, only15 (26%) out of 58 patients had received pdC1INH at least once until 2008, and only2 (3.4%) had used it regularly. After worldwide approval of the new drugs for the treatment of acute HAE attacks, adding icatibant to pdC1INH in Argentina, and after publication of the therapeutic guide for the country, 42 (82%) out of 51 patients from the original group has pdC1INH available to treat their next attack. However, 16 (18%) patients continue without access to medication and other 15 (35.7%) obtain their therapy spuriously through some other affected relative in their environment. Only 12 (28.6%) patients of the group self-treated at home. Access to treatment has greatly improved, but needs to be extended to all patients and self-treatment at home should be encouraged.

Cardioprotective effect of ornitho-kinin in an anesthetized, open-chest chicken model of acute coronary occlusion

The generation of bradykinin (BK; Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg) in blood and kallidin (Lys-BK) in tissues by the action of the kallikrein-kinin system has received little attention in non-mammalian vertebrates. In mammals, kallidin can be generated by the coronary endothelium and myocytes in response to ischemia, mediating cardioprotective events. The plasma of birds lacks two key components of the kallikrein-kinin system: the low molecular weight kininogen and a prekallikrein activator analogous to mammalian factor XII, but treatment with bovine plasma kallikrein generates ornitho-kinin [Thr6,Leu8]-BK. The possible cardioprotective effect of ornitho-kinin infusion was investigated in an anesthetized, open-chest chicken model of acute coronary occlusion. A branch of the left main coronary artery was reversibly ligated to produce ischemia followed by reperfusion, after which the degree of myocardial necrosis (infarct size as a percent of area at risk) was assessed by tetrazolium staining. The iv injection of a low dose of ornitho-kinin (4 µg/kg) reduced mean arterial pressure from 88 ± 12 to 42 ± 7 mmHg and increased heart rate from 335 ± 38 to 402 ± 45 bpm (N = 5). The size of the infarct was reduced by pretreatment with ornitho-kinin (500 µg/kg infused over a period of 5 min) from 35 ± 3 to 10 ± 2 percent of the area at risk. These results suggest that the physiological role of the kallikrein-kinin system is preserved in this animal model in spite of the absence of two key components, i.e., low molecular weight kininogen and factor XII.

Rocha e Silva, the snake venom and 50th anniversary of bradykinin discovery

In this article we emphasize the importante of the snake venom toxins for the development of the autopharmacology concept (Sir Henry Dale, 1933) and how they led to the discovery of bradykinin and to the development of the first active-site directed inhibitor of the angiotensin converting enzyme. We also describe the most recent development concerning the possible role of bradykinin potentiating peptides from Bothrops jararaca venom for the cardiovascular pharmacology. A fundamental step leading to what can be considered one of the most significant contributions given by Brazilian scientists to biomedical sciences, was originated in the efforts of Rocha e Silva to identify and characterize the actors involved in anaphylaxis. His main scientific motivation and efforts which influenced a whole generation of prominent Brazilian scientists, should be reminded when we are commemorating the 50th anniversary of the bradykinin discovery. One important consequence of the use of the Bothrops jararaca venom leading to the discovery of bradykinin was the development of captopril, the most successful drug used by milions of people all over the world to treat arterial hypertension. The purpose of this article is to dissect some of the historical background which aim to stress the need for the adequate scientific environment allowing the privileged scientific minds to uncover secrets of Nature for the benefit of mankind.