Brazilian guidelines for the diagnosis and treatment of hereditary angioedema

Abstract

Hereditary angioedema is an autosomal dominant disease characterized by edema attacks with multiple organ involvement. It is caused by a quantitative or functional deficiency of the C1 inhibitor, which is a member of the serine protease inhibitor family. Hereditary angioedema is unknown to many health professionals and is therefore an underdiagnosed disease.The causes of death from hereditary angioedema include laryngeal edema with asphyxia. The estimated mortality rate in patients in whom the disease goes undetected and who are therefore incorrectly treated is 25-40%. In addition to edema of the glottis, hereditary angioedema often results in edema of the gastrointestinal tract, which can be incapacitating. Patients with hereditary angioedema may undergo unnecessary surgical interventions because the digestive tract can be the primary or only organ system involved, thus mimicking acute surgical abdomen. It is estimated that patients with hereditary angioedema experience some degree of disability 20-100 days per year.The Experts in Clinical Immunology and Allergy of the “Associação Brasileira de Alergia e Imunopatologia - ASBAI” developed these guidelines for the diagnosis, therapy, and management of hereditary angioedema.

Brazilian Guidelines for Hereditary Angioedema Management - 2017 Update Part 1: Definition, Classification and Diagnosis

“…Since the first Brazilian Hereditary Angioedema Guidelines were published in 2011, the body of knowledge regarding hereditary angioedema (HAE) has increased, and its management has improved 1 - 6 . More patients have been diagnosed with HAE, and new treatments for the disease have become available in our country.…”

“…HAE remains unknown to and underdiagnosed by many health care providers. The long periods from the onset of symptoms to the diagnosis of the disease and from diagnosis to access to therapy increase HAE-related morbidity and mortality, thus affecting the quality of life (QoL) of patients and their families 1 , 2 , 5 - 9 . HAE patients visit an average of 4.4 physicians before receiving a correct diagnosis, and 65% of these patients are misdiagnosed 10 , 11 .…”

“…However, in a significant percentage of cases, the genetic defect remains unknown. Therefore, the following two subtypes have been recognized: HAE with normal C1-INH and FXII mutation (FXII-HAE) and HAE with normal C1-INH and unknown genetic defect (U-HAE) 1 , 2 , 5 - 9 , 24 . It has been recommended that clinicians no longer use the term HAE type III because it is not associated with C1-INH deficiency.…”

The Icatibant Outcome Survey: 10 years of experience with icatibant for patients with hereditary angioedema

“…[12][13][14][15][16] Following results from controlled trials, icatibant was approved in 2008 for treatment of acute HAE attacks in adults aged ≥18 years in the European Union and then, as of January 2021, in 47 countries, including the United States, Brazil and Japan. [17][18][19][20] Based on an open-label phase 3 study in children/adolescents with HAE-1/2, 21 the European indication was further extended in 2017 to include treatment of attacks in paediatric patients aged 2 to <17 years, 22 providing an important treatment option for a population with limited access to therapies. Icatibant is administered subcutaneously, available as a prefilled syringe and licensed for self-administration by a patient/caregiver with appropriate training.…”

Improving the Management of Hereditary Angioedema

“…Using the guidelines as an orientation, but attending patients with their various phenotypes in a personalized way, is an art. The publication of the "Brazilian Guidelines for the Diagnosis and Treatment of Hereditary Angioedema" in 2011 1 , 2 was a milestone that boosted the care, education and research in HAE in the country. Knowledge about the disease improved, patient diagnoses increased and were made earlier, and new treatments became available, providing great improvement in HAE management.…”