The prevalence of FVL was similar to that found in the control group whereas PT-20210A was significantly more frequent in APS patients than in normal controls (2.0%, p=0.02).
Heterozygous PTG20210A contributes little to the thrombotic tendency of primary APS whereas plasma HC may influence age at first event and number of events.
In addition, the various aPL (anticardiolipin antibodies, lupus anticoagulant, anti-beta2GPI antibodies, antiphosphatidylserine/prothrombin antibodies) show similar HLA association, again independent of the clinical context (primary APS or SLE), and across various ethnic groups.
There were no differences in the prevalence of recurrent thrombosis before or after APS diagnosis in patients with or without prothrombin gene polymorphism.
Sera from 61 obstetrical seronegative APS (SN-APS) patients were analyzed for anti-cardiolipin antibodies (aCL) using thin-layer chromatography (TLC)-immunostaining, for anti-cardiolipin/vimentin antibodies (aCL/Vim), anti-phosphatidylserine/prothrombin antibodies, IgA anti-β<sub>2</sub>glycoprotein I antibodies (aβ<sub>2</sub>GPI), and IgA aCL antibodies by enzyme-linked immunosorbent assay.
Prothrombin fragment F1 + 2 (F1 + 2) and thrombin-antithrombin (TAT) have been assessed in antiphospholipid syndrome (APS) but without evaluating a direct relationship with antiphospholipid (aPL) antibody titers.
Phosphatidylserine/Prothrombin complex antibody (aPSPT) though associated with various APS manifestations, is not included in the revised Sapporo Criteria.
Current recommendations advocate for the use of anti-Xa activity monitoring in the setting of APS because of the common laboratory interaction with commercially available tests, such as prothrombin and activated partial thromboplastin times .