Laboratory identification of antiphospholipid antibodies (aPAs) began in 1907, when Wasserman introduced a diagnostic test for syphilis (Wasserman, 1907). The antigenic component of the Wasserman test was later identified as cardiolipin (Pangborn, 1941). Subsequently all syphilis tests were performed using a reagent containing cardiolipin extracted from bovine heart and, with the wide scale introduction of this test, it soon became apparent that there were a large number of patients whose sera contained antibodies that reacted with the reagent, but who had no clinical evidence of syphilis (Moore and Mohr, 1952). This phenomenon was termed the biological false positive serological test for syphilis (BFP-STS) and was identified in a large number of subjects with transient infections unrelated to syphilis. In the majority of cases, the positive reaction disappeared after resolution of the infection, however, in the remainder of cases, the positive test persisted over months or years. The two groups were classified as acute and chronic BFP-STS accordingly. With further study of patients with chronic BFP-STS, a high incidence of autoimmune disease, particularly systemic lupus erythematosus (SLE) was noted (Moore and Lutz, 1955).