Repeated attacks of type III hereditary angioedema with factor XII mutation during pregnancy.

In type III hereditary angioedema (HAE type III), the phenotype is the same as type I and type II disease, but the level and function of C1-esterase inhibitor (C1-INH) is normal. Hereditary angioedema type III has been described as an oestrogen-sensitive form because it can be triggered or aggravated by exposure to high oestrogen levels as seen during pregnancy, especially when associated with Factor XII mutation. This case report describes the evolution and management of repeated angioedema attacks during pregnancy in a woman with HAE, with normal levels and function of C1-INH (type III); and a mis-sense mutation of factor XII. The physiopathology and genetic features, the unpredictability of clinical manifestations and the management during pregnancy and delivery are discussed.

[Review of a new subtype of hereditary angio-oedema with normal complement C1-inhibitor].

Hereditary angio-oedema (HAE) is a rare, potentially fatal disease characterized by recurrent swelling of skin and mucosa. Besides HAE with quantitative (type I) or qualitative (type II) deficiency of complement C1-inhibitor (C1-INH), a new subtype of HAE is now described with normal levels of C1-INH. This subtype is possibly underdiagnosed, and a treatment regimen and general knowledge about the condition is still in its infancy. The purpose of this article is to inform Danish doctors about the disease to identify more Danish patients.

Hereditary angioedema with an estrogen trigger in a 12-year-old.

BACKGROUND: Hereditary angioedema (HAE) is rare autosomal dominant genetic disorder, commonly affecting girls around the menarche, which manifests clinically as recurrent episodes of angioedema. Laryngeal edema can lead to asphyxiation and death. Traditionally hormones have been avoided in the management due a reported association with flares in the literature. This case describes an alternative management with a progestin. CASE: A 12 year old HAE sufferer failed to receive relief from her symptoms of angioedema with standard treatment. A trial of depot medroxyprogesterone acetate has resulted in resolution of her symptoms for the last 14 months. CONCLUSION: Although estrogens and progestins have been avoided in the management of HAE in the past, the reasons for this are based only on a small number of case reports. In this case, successful treatment with depot medroxyprogesterone acetate indicates that progestins, as an alternative management for estrogen-triggered HAE, certainly warrants further research.

Clinical, biochemical, and genetic characterization of type III hereditary angioedema in 13 Northwest Spanish families.

BACKGROUND: A new variant of hereditary angioedema has been reported during the last decade. Three main characteristics distinguish it from classic hereditary angioedema: normal C1 inhibitor activity, predominance in women, and different genetic alterations. OBJECTIVE: To assess the symptoms, laboratory findings, and treatment of a population with type III hereditary angioedema from Northwest Spain. METHODS: We studied 29 patients (26 female and 3 male) from 13 different families. RESULTS: The 26 female patients showed a similar clinical pattern to the classic forms of hereditary angioedema, and 22 of these patients had the estrogen-dependent phenotype. Three patients had a negative family history, and 1 of the parents was confirmed as an asymptomatic carrier in 2 of them. All had functional C1 inhibitor activity within the normal range in periods without high estrogen levels, but during attacks (in female patients) and pregnancy, activity decreased to below 50%. One male patient had normal C1 inhibitor activity during attacks, and he was initially diagnosed as having idiopathic angioedema. The C4 and antigenic C1 inhibitor levels were always normal. All studied patients had the c.1032C>A, Thr309Lys mutation in the factor XII gene. The mutation was also found in asymptomatic relatives: 5 of 6 men studied and 1 of 8 women studied. CONCLUSION: Positive family history is a diagnosis criterion, but it could be lacking because there may be asymptomatic relatives, primarily males.

An overview of novel therapies for acute hereditary angioedema.

Hereditary angioedema is an episodic swelling disorder with autosomal dominant inheritance. Attacks are characterized by nonpitting edema of external or mucosal body surfaces. Patients often present with swelling of the extremities, abdominal pain, and swelling of the mouth and throat, which can at times lead to asphyxiation. The disease is caused by a mutation in the gene encoding the complement C1-inhibitor protein, which leads to unregulated production of bradykinin. Long-term therapy has depended on the use of attenuated androgens or plasmin inhibitors but in the US there was, until recently, no specific therapy for acute attacks. As well, many patients with hereditary angioedema in the US were either not adequately controlled on previously available therapies or required doses of medications that exposed them to the risk of serious adverse effects. Five companies have completed or are currently conducting phase III clinical trials in the development of specific therapies to terminate acute attacks or to be used as prophylaxis. These products are based on either replacement therapy with purified plasma-derived or recombinant C1-inhibitor, or inhibition of the kinin-generating pathways with a recombinant plasma kallikrein inhibitor or bradykinin type 2 receptor antagonist. Published studies thus far suggest that all of these products are likely to be effective. These new therapies will likely lead to a totally new approach in treating hereditary angioedema.