Hereditary angioedema (HAE), a rare but life-threatening condition, manifests as acute attacks of facial, laryngeal, genital, or peripheral swelling or abdominal pain secondary to intra-abdominal edema. Resulting from mutations affecting C1 esterase inhibitor (C1-INH), inhibitor of the first complement system component, attacks are not histamine-mediated and do not respond to antihistamines or corticosteroids. Low awareness and resemblance to other disorders often delay diagnosis; despite availability of C1-INH replacement in some countries, no approved, safe acute attack therapy exists in the United States. The biennial C1 Esterase Inhibitor Deficiency Workshops resulted from a European initiative for better knowledge and treatment of HAE and related diseases. This supplement contains work presented at the third workshop and expanded content toward a definitive picture of angioedema in the absence of allergy. Most notably, it includes cumulative genetic investigations; multinational laboratory diagnosis recommendations; current pathogenesis hypotheses; suggested prophylaxis and acute attack treatment, including home treatment; future treatment options; and analysis of patient subpopulations, including pediatric patients and patients whose angioedema worsened during pregnancy or hormone administration. Causes and management of acquired angioedema and a new type of angioedema with normal C1-INH are also discussed. Collaborative patient and physician efforts, crucial in rare diseases, are emphasized. This supplement seeks to raise awareness and aid diagnosis of HAE, optimize treatment for all patients, and provide a platform for further research in this rare, partially understood disorder.

A ngioedema -a self-limited, localized swelling that involves subcutaneous tissues or mucosa -can involve the face and other areas. Skin colour is usually unchanged, although it may be heralded by erythema marginatum. There is no burning sensation and itchiness is generally absent. Lesions tend to be large and without clear demarcation; most resolve within 2 or 3 days. 1Frequently the result of the release of histamine, angioedema is often associated with urticarial flares (hives; the association is often called urticaria-angioedema syndrome) and responds to antihistamines and corticosteroids.2 Occasionally, angioedema occurs without urticaria, does not respond to drugs against allergies and tends to last 5-7 days -for example, when it is caused by a deficiency in plasma of C1 esterase inhibitor (C1Inh).To investigate and form classifications for different forms of angioedema unaccompanied by urticaria, we analyzed 929 consecutive patients referred to our university hospital over an 11-year period (January 1993 through December 2003). MethodsOur outpatient clinic for angioedema is a tertiary-level centre where patients are referred mostly by specialists. All clinic patients with a history of recurrent angioedema without major urticaria between January 1993 and December 2003 were considered for the study.From each patient, we obtained a clinical history with information about allergies and their relation to potential causative agents (e.g., foods, drugs, chemicals) and carried out a complete physical examination. We obtained sinus and dental radiographs as well as test results for blood cell count, serum protein electrophoresis, erythrocyte sedimentation rate, Creactive protein, hepatic enzymes, renal function, thyroid function and anti-tissue antibodies (antinuclear antibodies and antibodies to extractable nuclear antigens, to doublestranded DNA, to thyroglobulin and to thyroperoxidase). Stool examinations (for ova and parasites) and urinanalyses were carried out, and pharyngeal and urine samples were cultured. Further specific analyses were performed if deemed necessary.If all test results were negative, response to long-term H1-

Scant information exists on the role of thrombophilia in extrahepatic portal vein obstruction (EHPVO). We studied 65 patients with EHPVO, 500 with deep vein thrombosis (DVT) of the lower limbs, and 700 healthy controls referred for thrombophilia screening, including the search for gain-of-function mutations in genes encoding coagulation factor V (factor V Leiden) and prothrombin (prothrombin G20210A); antithrombin, protein C, and protein S deficiency; and hyperhomocysteinemia. At least one abnormality in the thrombophilia screening was found in 40% of patients with either EHPVO or lower limb DVT and in 13% of controls, for odds ratios of 4.0 (95% CI, 2.3-7.0) and 4.4 (95% CI, 3.3-5.9), respectively. Statistically significant associations with EHPVO were observed for the prothrombin G20210A mutation (odds ratio, 8.1; 95% CI, 3.8-17.5) and the deficiencies of antithrombin, protein C, or protein S taken together (odds ratio, 4.5; 95% CI, 1.1-18.0). The odds ratio for the prothrombin G20210A was approximately twice that for lower limb DVT. Patients with factor V Leiden had an odds ratio for EHPVO of 0.8 (95% CI, 0.1-6.4) and for lower limb DVT of 7.5 (95% CI, 4.4-13.0). The odds ratio for EHPVO in patients with hyperhomocysteinemia was 2.0 (95% CI, 0.9-4.9). At variance with lower limb DVT, oral contraceptive use was not associated with an increased risk of EHPVO. Myeloproliferative disorders were diagnosed in 35% of patients with EHPVO. In conclusion, the risk for EHPVO is increased in the presence of thrombophilia resulting from the prothrombin G20210A mutation and from the deficiencies of the naturally occurring anticoagulant proteins, but not from factor V Leiden. (HEPATOLOGY 2005;41:603-608.)

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. Next-generation sequencing study finds an excess of rare, coding single-nucleotide variants of ADAMTS13 in patients with deep vein thrombosis. J Thromb Haemost 2013; 11: 1228-39.Summary. Background: The considerable genetic predisposition to deep vein thrombosis (DVT) is only partially accounted for by known genetic risk variants. Rare single-nucleotide variants (SNVs) of the coding areas of hemostatic genes may explain part of this missing heritability. The ADAMTS13 and VWF genes encode two interconnected proteins with fundamental hemostatic functions, the disruption of which may result in thrombosis. Objectives: To study the distribution and burden of rare coding SNVs of ADAMTS13 and VWF found by sequencing in cases and controls of DVT. Patients/Methods: The protein-coding areas of 186 hemostatic/proinflammatory genes were sequenced by next-generation technology in 94 thrombophilia-negative patients with DVT and 98 controls. Gene-specific information on ADAMTS13 and VWF was used to study the association between DVT and rare coding SNVs of the two genes. Results: More than 70 billion base pairs of raw sequence data were produced to sequence the 700-kb target area with a median redundancy of 9 45 in 192 individuals. Most of the 4366 SNVs identified were rare and nonsynonymous, indicating pathogenetic potential. Rare (frequency of < 1%) and low-frequency (< 5%) coding SNVs of ADAMTS13 were associated with DVT (prevalence 17% vs. 4%; odds ratio [OR] 4.8 and 95% confidence interval [CI] 1.6-15.0 for rare coding; prevalence 36% vs. 23%, OR 1.9 and 95% CI 1.0-3.5 for low-frequency coding). Patients with rare coding SNVs of ADAMTS13 had lower plasma levels of ADAMTS-13 activity than patients without them. SNVs of VWF were not associated with DVT. Conclusions: We found an excess of rare coding SNVs of the ADAMTS13 gene in patients with DVT.

C1 inhibitor (C1-INH) is a serine protease inhibitor (serpins) that inactivates several different proteases in the complement, contact, coagulation, and fibrinolytic systems. By its C-terminal part (serpin domain), characterized by three beta-sheets and an exposed mobile reactive loop, C1-INH binds, and blocks the activity of its target proteases. The N-terminal end (nonserpin domain) confers to C1-INH the capacity to bind lipopolysaccharides and E-selectin. Owing to this moiety, C1-INH intervenes in regulation of the inflammatory reaction. The heterozygous deficiency of C1-INH results in hereditary angioedema (HAE). The clinical picture of HAE is characterized by bouts of local increase in vascular permeability. Depending on the affected site, patients suffer from disfiguring subcutaneous edema, abdominal pain, vomiting and/or diarrhoea for edema of the gastrointestinal mucosa, dysphagia, and dysphonia up to asphyxia for edema of the pharynx and larynx. Apart from its genetic deficiency, there are several pathological conditions such as ischemia-reperfusion, septic shock, capillary leak syndrome, and pancreatitis, in which C1-INH has been reported to either play a pathogenic role or be a potential therapeutic tool. These potential applications were identified long ago, but controlled studies have not been performed to confirm pilot experiences. Recombinant C1-INH, produced in transgenic animals, has recently been produced for treatment of HAE, and clinical trials are in progress. We can expect that the introduction of this new product, along with the existing plasma derivative, will renew interest in exploiting C1-INH as a therapeutic agent.