Deep venous thrombosis associated with acquired angioedema type II in a patient heterozygous for the mutation of factor V Leiden: effective treatment and follow-up for four years.

Thromb Haemost 2006; 95: 898–9 Deficiency of the C1-inhibitor (C1-INH) is a very rare cause of angioedema. A hereditary (1) and an acquired form (2, 3) of C1-INH deficiency have been described. Two types of acquired angioedema (AAE) exist: type I is associated with lymphoproliferative disorders, whereas type II is characterized by autoantibodies against C1-INH (4). Clinically, AAE is indistinguishable from hereditary angioedema (HAE) (5, 6). Patients suffer from recurrent edematous attacks that involve subcutaneous or submucosal tissue (of the larynx and gastrointestinal tract). Patients with AAE do not have a family history of angioedema, and their symptoms usually develop after the age of forty. Diagnosis is based on laboratory findings, i.e. decreased complement (C) C2, C4, C1-INH plasma concentrations, decreased C1-INH activity(5, 6) and normal C3 levels, along with low plasma C1q levels [the latter are usually normal in HAE(7)]. In this paper, we report the case of a female patient with type II AAE, where angioedema was associated with recurrent deep venous thrombosis. A review of the literature yielded only one report of two angioedema cases, where AAE type I was associated with thrombotic (both arterial and venous) disorders, as reported by Wautier et al. (8). Our paper discusses the possible relationship between acquired C1-INH deficiency and an enhanced propensity for thrombosis.