Acquired Protein S Deficiency, Likely due to Anti-PS Autoantibodies, following a Thrombotic Event in a Patient with a Systemic Lupus erythematosus - Morange, P E; Alessi, M C; Barthet, M C; Aillaud, M F; Harlé, J R; Piquet, P; Juhan-Vague, I (Thrombosis and Haemostasis, 1997)