[Ecchymotic angioedema revealing childhood systemic lupus erythematosus with anti-C1q antibodies]. / Angioedèmes à évolution ecchymotique révélant un lupus érythémateux systémique de l'enfant avec anticorps anti-C1q.

BACKGROUND: Hypocomplement urticarial vasculitis syndrome may be the presenting sign of systemic lupus erythematosus. Hypocomplement urticarial vasculitis presents as atypical urticaria associated in 50% of cases with angioedema. On laboratory investigation, hypocomplementaemia is the characteristic feature, with reduced C3, C4 and C1q. This disease is very rare in children. PATIENTS AND METHODS: An eight-year-old girl was hospitalised for relapsing urticaria with ecchymotic angioedema present for one year, in a setting of impaired general health and fever. Screening for native anti-DNA and antinuclear antibodies was positive. Analysis of complement revealed activation of the classical pathway with reduced CH50, C4 and C3. These anomalies persisted outside active episodes. The C1q fraction was completely depressed and screening for anti-C1q was positive. There was no quantitative or qualitative deficit in C1-esterase inhibitor. Direct immunofluorescence of skin lesions demonstrated deposits of immunoglobulin and complement. These episodes of angioedema persisted despite long-term systemic corticosteroid therapy (1mg/kg per day). DISCUSSION: This is the first reported case of hypocomplement urticarial vasculitis syndrome arising from systemic lupus erythematosus in a child exhibiting anti-C1q antibodies. Furthermore, this case is original because of the highly ecchymotic nature of the lesions. In the presence of angioedema with ecchymotic progression associated with atypical chronic urticaria, a diagnosis of hypocomplement urticarial vasculitis syndrome should be considered.

[Transfusion-related acute lung injury]. / Oedème pulmonaire lésionnel aigu post-transfusionnel ou Trali.

OBJECTIVES: The transfusion-related acute lung injury frequency was for a long time underestimated since it lacked both a widely accepted clinical definition and a comprehensive etiologic description. Recent clinical and biological data have underlined its frequency and have allowed a better understanding of its mechanisms. CURRENT KNOWLEDGE AND KEY POINTS: Trali is an interstitial lung injury occurring within 6 hours after the beginning of a blood transfusion. This time relationship between blood injection and the occurrence of lung edema is sufficient for a positive diagnosis, if any other cause of interstitial lung edema have been excluded. The clinical definition relies on a desaturation of arterial blood associated to a lack of any cardiac failure or circulation overload. The link between transfusion and lung edema is not univocal and several categories of mechanisms have been discussed. At least 2 of them are well identified; the first one is an immune conflict, and the second one is an activation of neutrophils by injection of biological modifiers such as lipids or CD40 soluble ligand. Evidences exist for the occurrence of Trali only in predisposing condition that mostly consists of a preceding leucostase in lung capillaries. Trali is treated like other lung interstitial edema by oxygen therapy and mechanical ventilation. FUTURE PROJECTS: A better knowledge of Trali offers the opportunity of improving the understanding of the role of blood transfusion in lung edema occurring in complex situations and open the way for a better definition of at risk patient and at risk blood components.