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.