Evaluation and optimization of laboratory criteria for Antiphospholipid Syndrome Diagnosis

Laboratory assays, used to detect the antiphospholipid antibodies（aPLs), are a major criterium for the classification of antiphospholipid syndrome (APS) and tailored treatment for patients with APS. Currently, the laboratory diagnosis of APS is still challenging due to the lack of standardization and the heterogeneity of aPLs antibodies. Antibodies recognizing the epitope of domain I (DI) of β2GPI have proved to be pathogenic. These results demonstrated that antiDI IgG potentially helps in identifying high-risk APS patients. In addition, it is important to verify the correct exposure of the cryptic epitope on DI to improve standardization of aPLs detection in all available antiDI assays. Furthermore, patients with isolated lupus anticoagulant (LAC) had a higher risk of thrombosis compared with patients with triple positive. These findings open the way for investigating new potentially important antigen targets in the pathogenesis of APS.