C1 inhibitor deficiency: consensus document

Abstract

SummaryWe present a consensus document on the diagnosis and management of C1 inhibitor deficiency, a syndrome characterized clinically by recurrent episodes of angio-oedema. In hereditary angio-oedema, a rare autosomal dominant condition, C1 inhibitor function is reduced due to impaired transcription or production of non-functional protein. The diagnosis is confirmed by the presence of a low serum C4 and absent or greatly reduced C1 inhibitor level or function. The condition can cause fatal laryngeal oedema and features indistinguishable from gastrointestinal tract obstruction. Attacks can be precipitated by trauma, infection and other stimulants. Treatment is graded according to response and the clinical site of swelling. Acute treatment for severe attack is by infusion of C1 inhibitor concentrate and for minor attack attenuated androgens and/or tranexamic acid. Prophylactic treatment is by attenuated androgens and/or tranexamic acid. There are a number of new products in trial, including genetically engineered C1 esterase inhibitor, kallikrein inhibitor and bradykinin B2 receptor antagonist. Individual sections provide special advice with respect to diagnosis, management (prophylaxis and emergency care), special situations (childhood, pregnancy, contraception, travel and dental care) and service specification.

International consensus on the diagnosis and management of pediatric patients with hereditary angioedema with C1 inhibitor deficiency

“…Unfortunately, these treatments have been licensed mainly for adults with pediatric licensing pending and ages for licenses varying by jurisdiction. At present, pdC1‐INH, rhC1‐INH and ecallantide (12 years and up; in Europe and USA, pdC1‐INH Be is licensed for all age groups) are the only agents licensed for pediatric acute treatment 14, 21, 24, 34, 100. There are few reports of use of pdC1‐INH in very young children and babies 101, 102.…”

A regional audit of experience managing C1 esterase inhibitor deficiency – cause of a potential airway emergency

“…C1-INHD-related laryngeal oedema is potentially lifethreatening and unlikely to respond to adrenaline or steroids [1], yet only half of patients carry written treatment advice. The distribution of advice cards, alongside encouragement to present these to attending physicians, may expedite provision of appropriate treatment.…”

“…Attacks may occur spontaneously or in response to triggers such as the trauma caused by surgery or oral instrumentation. Best practice for the management of this condition, which has a prevalence of 1:50 000, has been published in a consensus document [1]. It advises that the treatment for acute attacks and prophylaxis for invasive procedures should include intravenous administration of the deficient C1 esterase inhibitor (C1-INH).…”

Evaluation de la prise en charge bucco-dentaire des patients atteints d’angio-œdèmes bradykiniques. A propos d’une enquête chez 72 patients

“…I) [3]. Actuellement les protocoles thérapeutiques le plus fréquem-ment utilisés font appel à la perfusion de concentré de C1-Inh en cas de crise sévère, et à la prescription d'androgènes à activité modérée et/ou d'acide tranexamique en traitement prophylactique [4]. Les facteurs déclenchants ne sont pas toujours faciles à mettre en évidence, ces oedèmes apparaissent généralement suite à un traumatisme ou à un stress, même minimes, dont font partie les soins bucco-dentaires.…”