RESUMEN
Antiphospholipid (aPL) syndrome, or APS,--a cluster of conditions that includes arterial or venous thromboses and thrombocytopenia, as well as recurrent fetal loss associated with elevation of aPL antibody--has been reported to occur 2-5 times more frequently in women than men. Strong familial associations lead to the suspicion that aPL positivity, estimated to be present in 2% of the population, is a heritable trait in some cases. Currently, 2 major categories of the illness are recognized--primary and secondary. Secondary APS may be associated with autoimmune disease, malignancy, infectious disease, or drug-induced states. Two assays, one for lupus anticoagulant antibodies and the other for anticardiolipin (aCL) antibodies, are recognized to be the gold standards for serologic diagnosis of the disease. Despite extensive attempts at international standardization of aCL test results, no consensus exists for a value beyond which the test is considered positive. Interestingly, a "dose-effect" relationship for aCL antibody titers has been noted--higher titers of the antibody correlate with increased numbers of thrombotic events. An experimental assay for antibody against beta 2-glycoprotein 1 (beta-2-GP1), a phospholipid-binding protein, may become the most important assay for aPL. Skin findings in APS include livedo reticularis, ulceration, gangrene, or purpura, and, when present, may be the key to diagnosis of this sometimes insidious syndrome. Anticoagulation, usually with warfarin, is the mainstay of therapy, although steroids, immunosuppressive agents, hydroxychloroquine sulfate, and plasmapheresis may all be beneficial adjunctive therapy.