Background Recently the role of anti-annexin II (AII) has been investigated in several autoimmune disorders. These antibodies were suspected to have a pathogenic potential, but their exact role in SLE and its association with thrombosis is still unclarified.
Objectives To investigate the role of anti-A II antibodies in SLE patients with and without antiphospholipid syndrome (APS) in comparison with Anticardiolipins (Acl) antibodies, Anti-beta2 glycoprotien I (β2GPI) and Lupus Anticoagulant (LAC).
Methods The study included 20 SLE patients with secondary APS, 20 SLE patients without any history of thrombosis and 10 age and sex matched healthy controls. Acl, LAC, β2GPI and Anti-AII antibodies were tested in all patients and controls.
Results There was a significantly higher mean levels of anti-AII in SLE patients with secondary APS than SLE without APS (1.575±0.769 and 0.765±0.664 respectively, P=0.032) and higher than controls (0.300±0.047, P=0.0031). Anti-AII antibodies were significantly more prevalent than other antibodies (table 1) in patients with SLE and APS than in SLE without thrombotic events (80% versus 40% respectively, P=0.0098) and controls (0%, P=0.0001), especially those with recurrent venous thrombosis and recurrent abortions. Compared to conventional markers for APS, anti-AII had the highest sensitivity, specificity and positive predictive value (PPV) (92%, 77.8%, 88.0% respectively) for APS. (table 2)
Conclusions Anti-AII is significantly increased in SLE with thrombosis compared to the conventional antibodies. Moreover, they showed the highest sensitivity, specificity and PPV for APS. This suggests a potential role of anti-AII as a novel marker for identifying APS, which could provide a target for new therapies. Further studies to test the diagnostic value of anti-AII in sero- negative APS are needed.
Disclosure of Interest None declared