Background: Hereditary angioedema (HAE) with C1-inhibitor deficiency (C1-INH-HAE)
is characterized by recurrent episodes of subcutaneous/submucosal edema, which may
be preceded by erythema marginatum (EM) as a prodromal symptom. Our aim was to analyze
the changes occurring in the parameters of the coagulation system during the development
of EM and HAE attacks. Materials and methods: Eight C1-INH-HAE patients (1 male, 7
females, median age: 41.7 years) were studied. Blood samples were obtained from all
patients (during symptom-free periods, EM, and HAE attacks), as well as from 20 sex-
and age-matched healthy controls. Prothrombin time (PT), activated partial thromboplastin
time (aPTT), fibrinogen, D-dimer, Factor V, Factor VII, Factor X, Factor XI, and Factor
XII levels were measured. Results: D-dimer levels were significantly lower, whereas
aPTT was significantly prolonged in healthy controls vs. the values measured during
the symptom-free period (p = 0.0497; p = 0.0043), in the presence of EM (p = 0.002;
p = 0.0002), or during HAE attacks (p < 0.0001; p = 0.0002). We observed the following
differences between samples taken during HAE attacks vs. in symptom-free periods:
D-dimer levels were significantly elevated (p = 0.0391), while aPTT was significantly
shorter during HAE attacks (p = 0.0159). D-dimer levels were significantly higher
during EM than in symptom-free periods (p = 0.0078). Comparing the samples drawn during
EM or during HAE attacks, there were no significant differences in the study parameters.
Conclusions: D-dimer levels were elevated during EM and this suggests that EM may
be part of the HAE attack. Nevertheless, further research into the complement and
kinin-kallikrein systems is needed in more patients for a better understanding of
the pathomechanism of EM.
