Tonello M, et al. - Using commercial ELISA assays, researchers prospectively evaluated the clinical significance of IgG/IgM antiphosphatidylserine/prothrombin (aPS/PT) antibodies in a cohort of 191 antiphospholipid antibody (aPL) carriers. First thrombotic event developed in 7.3% of of the aPL carriers. The investigators noted significant prevalence of IgG but not IgM aPS/PT antibodies among these aPL carriers. Findings suggested that the risk score for thrombosis in aPL carriers could be improved with the addition of IgG aPS/PT antibodies to triple aPL positivity and thrombosis risk factors.