Determination of Specific Biomarkers of Acute Attack of Angioedema Within Pediatric Population

In emergency room, this is crucial to diagnose an acute attack of hereditary angioedema (HAE) to quickly provide the efficient treatment. Currently, there is no specific biomarker for acute attack of bradykinin-mediated angioedema to help clinicians for patient care. However, previous works are carried out for that purpose. All the potential candidate biomarkers must be validated in prospective studies to estimate their specificity and sensitivity values, and to understand their potential utility in patient care.

The main goal of this clinical trial is to estimate the diagnostic value of VE-cadherin in pediatric population, for the differential diagnosis between HAE crisis and angioedema resulting of mast cell activation crisis (the main differential diagnosis of HAE).

Inclusion Criteria:

For HAE: patient with a documented diagnosis of HAE:

• type I (from an antigenic deficiency of the C1 esterase inhibitor) or type II (from a functional deficiency of the C1 esterase inhibitor). The existence of a mutation in SERPING1 was not necessary for the inclusion
• HAE with normal C1-INH (ex type III) with a required mutation in FXII gene or with a typical family history of HAE diagnosed by a specialized physician belonging to CREAK network.

For AE resulting of mast cell activation: a documented diagnosis of AE resulting of mast cell activation included:

• mastocytosis,
• chronic spontaneous urticaria,
• acute urticaria after exposure of allergen during allergy challenge tests,
• mast cell activation syndrome.

For the control group:

• composed of patients who presented a stabilized disease (that was not infectious, not auto-inflammatory or inflammatory disease and without implication of endothelial cells).

Exclusion Criteria:

• Over 18 years or under 1 year.
• Diagnosis of HAE with a normal C1 esterase inhibitor or AE of unknown aetiology.
• Patients with HAE who received an acute attack treatment before the blood sample (the C1 esterase inhibitor concentrate or a bradykinin B2 receptor antagonist); patients with HAE who received a prophylactic treatment (danazol).
• Patients who were treated by omalizumab or corticosteroid treatment.