Auto-anticorps dirigés contre la protéine S : une urgence médicale

Abstract

AbstractBoth acquired and inherited protein S deficiencies expose patients to the risk of thrombosis. Acquired deficiency, linked to the presence of a specific autoantibody directed against protein S, can lead to a severe disease. They may be responsible for thrombosis, but also for extensive necrotic purpura, which constitutes a medical emergency. It is often associated with disseminated intravascular coagulation and also deep venous thrombosis. The etiology is usually post-infectious, following chickenpox or other viral or bacterial infections.Biological diagnosis is an emergency. It must include a hemogram and hemostasis tests to reveal disseminated intravascular coagulation, and to measure protein S activity. If the results suggest the presence of autoantibodies to protein S, the Elisa method should be used quickly.Therapeutic management is also urgent. Effective anticoagulation must be introduced as quickly as possible, combined with transfusions of fresh frozen plasma to correct coagulation factors. Plasma exchange and intravenous immunoglobulins are then used to eradicate the autoantibody.