Treatment of hereditary angioedema due to C1 inhibitor deficiency in Argentina

The benefits of the worldwide approval of new drugs for the treatment of acute C1-INH-HAE attacks may still not reach all patients. Identifying the current barriers in the access to medication, as well as conducting a detailed assessment of the progress in this area, is essential to achieve universal treatment. Two hundred and twenty five patients registered in the Argentina Hereditary Angioedema Patient Association (AHAEPA) were randomly selected and invited to participate in a web based questionnaire on accessibility to icatibant and pdC1-INH, self-treatment, delay to treatment, and coverage. The data retrieved was compared to our previous reports in 2008 and 2013. We collected 156/225 answers. One hundred and eighteen (76%) patients have either pdC1-INH (n = 86), icatibant (n = 10) or both (n = 22), while 38 (24%) do not have access to treatment. In 2008, 26% had access while 82% had it in 2013. Thirty-two subjects (22%) self-inject themselves, similar to 29% in 2013, even though between studies, widespread self-injection training activities have taken place. However, considering injections by proxy, home treatment reached 56%. Only half of the patients decide to receive treatment early during the attack. Ninety-nine patients (63%) have full coverage, thirty (19%) have no coverage at all and the rest only obtain partial reimbursement. Twenty-nine families (31%) share a single treatment dose of the medication, better than 36% in 2013. Argentina's C1-INH-HAE patients had a sustained improvement in their access to medication. Efforts should continue to further improve accessibility and optimal management of HAE acute attacks to all patients in the country.

La aprobación mundial de los medicamentos para el ataque agudo del angioedema hereditario (HAE) no beneficia a todos los pacientes. Es necesario conocer las barreras de acceso a la medicación para el tratamiento universal. Doscientos veinticinco pacientes, registrados en la Asociación de Pacientes con Angioedema Hereditario (AHAEPA), fueron encuestados por internet acerca de su accesibilidad al icatibant y al concentrado del inhibidor de C1 (pdC1-INH), a la auto inyección de la medicación, al retraso del tratamiento y a la cobertura del medicamento. Comparamos esta información con la obtenida en nuestros estudios de 2008 y 2013. Recolectamos 156/225 respuestas. Ciento dieciocho (76%) pacientes tienen pdC1-INH (n = 86), icatibant (n = 10) o ambos (n = 22), mientras que 38 (24%) no tienen medicación. En 2008, 26% tenían acceso y en 2013, 82%. Treinta y dos (22%) se autoinyectan la medicación, similar al 29% en 2013. Sumando las aplicaciones por profesionales de la salud o familiares en la casa, el tratamiento fuera de las instituciones médicas alcanza el 56%. Solo la mitad decide tratarse tempranamente. Noventa y nueve (63%) tiene cobertura del 100%, 30 (19%) no tiene ningún tipo de cobertura, y el resto la tiene en forma parcial. Veintinueve familias (31%), solo tienen una dosis de tratamiento para todos, mejor que el 36% en 2013. Los pacientes con C1-INH-HAE han tenido una mejoría sustancial en el acceso a la medicación. Igualmente, los esfuerzos deben continuar para mejorar la accesibilidad y tratamiento óptimo de todos.

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.

Functional expression of kinin B1 and B2 receptors in mouse abdominal aorta

Previous studies have shown that the vascular reactivity of the mouse aorta differs substantially from that of the rat aorta in response to several agonists such as angiotensin II, endothelin-1 and isoproterenol. However, no information is available about the agonists bradykinin (BK) and DesArg9BK (DBK). Our aim was to determine the potential expression of kinin B1 and B2 receptors in the abdominal mouse aorta isolated from C57BL/6 mice. Contraction and relaxation responses to BK and DBK were investigated using isometric recordings. The kinins were unable to induce relaxation but concentration-contraction response curves were obtained by applying increasing concentrations of the agonists BK and DBK. These effects were blocked by the antagonists Icatibant and R-715, respectively. The potency (pD2) calculated from the curves was 7.0 ± 0.1 for BK and 7.3 ± 0.2 for DBK. The efficacy was 51 ± 2 percent for BK and 30 ± 1 percent for DBK when compared to 1 æM norepinephrine. The concentration-dependent responses of BK and DBK were markedly inhibited by the arachidonic acid inhibitor indomethacin (1 æM), suggesting a mediation by the cyclooxygenase pathway. These contractile responses were not potentiated in the presence of the NOS inhibitor L-NAME (1 mM) or endothelium-denuded aorta, indicating that the NO pathway is not involved. We conclude that the mouse aorta constitutively contains B1 and B2 subtypes of kinin receptors and that stimulation with BK and DBK induces contractile effect mediated by endothelium-independent vasoconstrictor prostanoids.

Kinins mediate the inhibition of atrial natriuretic peptide diuretic effect induced by pepsanurin

Pepsanurin is a peptidic fraction resulting from pepsin digestion of plasma globulins, that inhibits ANP renal excretory actions. We studied whether kinin-like peptides mediate the anti-ANP effect by testing if pepsanurin: 1) was blocked by the kinin B12 receptor antagonist HOE-140, 2) was produced from kininogen, and 3) was mimicked by bradykinin. Anti-ANP activity was assessed in anesthetized female rats by comparing the excretory response to two ANP boluses (0.5 mug iv) given before and after ip injection of test samples. Pepsanurin from human or rat plasma (1-5 mL/Kg), and bradykinin (5-20 mug/Kg), dose-relatedly inhibited ANP-induced water, sodium, potassium and cyclic GMP urinary excretion, without affecting arterial blood pressure. The same effect was exerted by pepsin hydrolysates of purified kininogen, whereas hydrolysates of kininogen-free plasma had no effect. HOE-140 (5 mug, iv) did not alter baseline, or ANP-induced excretion, but blocked the anti-ANP effects of pepsanurin. Histamine (15 mug/Kg) plus seroalbumin hydrolysates did not affect ANP response, despite inducing larger peritoneal fluid accumulation as compared with pepsanurin or bradykinin. We concluded that kinins cleaved from kininogen mediate the anti-ANP effects of pepsanurin by activation of kinin B2 receptors, independently of changes in systemic arterial pressure or peritoneal fluid sequestration.

Characterization of the receptors responsible for the diphasic effect of bradykinin in rat duodenum

The response of the rat duodenum to bradykinin (BK) consists of relaxant and contractile components, which have been atributed to different receptor types. To characterize the receptor responsible for this diphasic response we studied the effects of BK analogues known to act on B1 or B2 receptors in other systems. DesArg**9-Leu**8-BK and Thi**5,**8DPhe**7-BK presented only relaxant and only contractile effects, respectively, whereas DArgOHyp883Thi**5,**8DPhe**7-BK was a potent antagonist of the relaxation (but not of the contraction) induced by BK. Our results show that the relaxant and contractile components of the rat duodenum's response to BK are due to B2 and B1 receptor subtypes, respectively