1. INOVA Diagnostics, Inc., 9900 Old Grove Road, San Diego, CA 92131-1638, USA
2. Antiphospholipid Standardization Laboratory, Division of Rheumatology, Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA
3. Laboratorio di Ricerche in Immunoreumatologia, Università di Milano, Istituto Auxologico Italiano, 20095 Cusano Milanino, Italy
4. Faculty of Medicine, University of Calgary, Calgary, AB, Canada T2N 4N1