Antiprothrombin antibody testing: detection and clinical utility.

Anticardiolipin antibody (aCL), anti-beta2 glycoprotein I antibodies, and lupus anticoagulant (LA) are the only laboratory tests considered within the revised criteria for the classification of the antiphospholipid syndrome (APS). Recently, antibodies against phosphatidylserine-prothrombin complex (aPS/PT) have been detected, and these antibodies, rather than antibodies against prothrombin alone, are closely associated with APS and LA. The sensitivity and specificity of aPS/PT for the diagnosis of APS were assessed in a population of patients with a variety of autoimmune disorders. aCL and aPS/PT have similar diagnostic value for APS, therefore aPS/PT should be further explored, not only for research purposes but also as a candidate for one of the laboratory criteria for the classification of the APS.