Clinical and Laboratory Characteristics That Differentiate Hereditary Angioedema in 72 Patients with Angioedema

Abstract

Early onset of AE, positive family history, recurrent AE in the extremities and GI tract, and suffocation are distinctive characteristics of HAE. A low serum level of C4 is a useful marker for making a differential diagnosis of HAE.

Presymptomatic genetic diagnosis of two siblings with hereditary angioedema, presenting with unusual normal levels of serum C4

“…However, the second measurement during an attack exhibited a low C4 level. 5 Therefore, normal C4 levels in the present cases may be attributable to the lack of the attacks of angioedema so far. Thus, although it has been generally agreed that low serum levels of C4 are a useful marker for HAE, normal serum C4 levels do not exclude the possibility of HAE.…”

“…According to Ohsawa et al, 5 the sensitivity and specificity of low C4 for HAE were 95.6% and 93.8%, respectively. In Ohsawa et al's case series, only one of 23 HAE patients showed a normal level of C4.…”

The use of tranexamic acid for on‐demand and prophylactic treatment of hereditary angioedema—A systematic review

“…Although C1‐INH has been demonstrated to be safe and effective, self‐administration and LTP are not licensed, and accessibility to treatment is challenging for many patients in Japan . In addition, awareness of HAE among physicians in Japan is low and the limited availability of effective therapies increases the burden of HAE . Diagnosis of HAE worldwide can take an average of 8.3 years; this figure is thought to be much longer in Japan .…”

“…73 Diagnosis of HAE worldwide can take an average of 8.3 years; this figure is thought to be much longer in Japan. 29,73,74 While danazol is available for off-label use, it has been associated with numerous side effects, including virilization, headaches, depression, and acne. In addition, the risk of adverse events in response to androgens increases the longer the duration of treatment.…”

The <i>ABC</i> of Angioedema: <i>A</i>ce Inhibitor, <i>B</i>radykinin, and <i>C</i>1-inhibitor Are Critical Players

“…Elevated levels of bradykinin due to activated kallikrein and factor XII are considered to increase the vascular permeability in HAE (8). In contrast to ACE-I-induced angioedema where most of laboratory tests are normal, including complement, HAE can be diagnosed by the decreased levels of complement C4 and C1-INH activity (9). The guidelines for HAE diagnosis and treatment in Japan are noted in reference 10 (10).…”