The Vth International Symposium on Antiphospholipid Antibodies (aPL), sponsored jointly by the Kingston Antiphospholipid Study (KAPS) Group and the Antiphospholipid Antibodies in Stroke Study Group (APASS) will be held in San Antonio, Texas on September 9-11 (with Satellite Symposia on September 12) at the Hyatt Regency San Antonio. The principal aims of this Symposium are to bring together a leading group of clinical and basic researchers to discuss the latest findings in research related to the phospholipid autoimmune response; the clinical syndromes associated with APL; the pathophysiologic mechanisms underlying these syndromes; and the most efficacious treatment strategies. This meeting will encourage communication, cross-fertilization of ideas and collaboration among researchers who represent the many basic and clinical science research disciplines actively studying aPL. The Scientific Program will include the following topics: (1) Origins and specificity of aPL Detection; (2) Pathogenic Mechanisms of Action: (1) Effects on the Coagulation System, (b) Animal Models; (3) Clinical Syndromes Mini-Symposium; (4) Methodological Approaches to the Detection of APL; (5) Treatment. The program will consist of oral communications, poster presentations, plenary sessions, workshops and commercial exhibits. Key investigators have been included from throughout the world to ensure expertise in all of these important areas. We anticipate that approximately 500 biomedical scientists and health professionals representing more than 15 basic science and clinical disciplines from over 25 countries will attend the 5th International Symposium on aPL. Because aPL. research is being done by scientists in many disciplines, the reports of important new advances often have limited exposure. This Symposium is, therefore, key in providing a forum for scientists involved in different aspects of this research to learn from one another in an efficient and timely manner.