Angioedema is a common condition, with multiple etiologies. Type 3 angioedema is caused by an increase in kininogenase activity responsible for an increased production of bradykinin. In some cases, it may be associated with clotting factor 12 mutations. However, other genetic abnormalities remain to be identified. Clinically, this angioedema type 3 is similar to types 1 and 2. The patient's vital prognosis is good if the diagnosis is made and if they have access to the appropriate treatment. Otherwise a significant morbidity is associated with it, hence the importance of being able to define a diagnostic marker. Videocapillaroscopy might be able to highlight abnormalities in the microcirculation of patients with a clinical display of angioedema. The purpose of this study is to highlight markers allowing to make an early diagnosis of angioedema. Functional analysis of factor XII in patients with symptoms of angioedema may be an interesting marker for diagnosis. Microcirculation abnormalities will also be evaluated by videocapillaroscopy, which may be another indicator of the disease.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
32
Factor XII (FXII, Hageman factor) will be measured in plasma. It is converted to FXIIa by an activator. The FXIIa protease cleaves a chromogenic substrate and releases p-nitroaniline (pNA), which can be measured photometrically.
Sequencing of exon 9 of franking introns of FXII, for identification of the p.Thr328Lys mutation.
It is an optical method to visualize the most superficial part of the cutaneous microcirculatory network. It provides morphological information.
CHU Brugmann
Brussels, Belgium
Plasma concentration of Factor XII
Plasma concentration of Factor XII
Time frame: 24 hours
Presence of p.Thr328Lys mutation
Genetic analysis : sequencing of the Factor VII gene. Presence/Absence of the p.Thr328Lys mutation (single nucleotide variation inducing a missense variant).
Time frame: 24 hours
Videocapillaroscopy result
It is an optical method to visualize the most superficial part of the cutaneous microcirculatory network. It provides morphological information.The result will be classified as 'normal' or 'abnormal' by the videocapillaroscopy specialist.
Time frame: 24 hours
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.