Antiprothrombin and antiannexin V antibodies imply risk of thrombosis in patients with systemic autoimmune diseases

Objective. To investigate the relationship between antiprothrombin (aPT) an d antiannexin V (aANX) autoantibodies of Ige isotype and thrombosis in pati ents with systemic autoimmune diseases. To compare the clinical relevance o f these antibodies to that of anticardiolipin (aCL), anti-beta(2)-glycoprot ein I antibodies (anti-beta(2)-GPI), and lupus anticoagulant (LAC). Methods. Serum IgG aPT, aANX, aCL, and anri-beta(2)-GPI levels were measure d by solid phase enzyme immunoassay in the sera of 70 patients with systemi c autoimmune diseases, 35 with antiphospholipid syndrome (APS) and 35 witho ut APS. Medical records were analyzed, and associations of the antibodies w ith clinical features of APS were assessed. Results. Patients with APS had higher frequency of aPT (p = 0.001) and aANX (p = 0.002) compared to patients without APS. Thrombotic events occurred m ore frequently in chose with aPT or aANX than those without (p = 0.005, p = 0.006, respectively). The presence of aPT and aANX was found to be highly specific for APS, Conclusion. Measurement of aPT and aANX antibodies may be of value in confi rming the diagnosis of APS, and in evaluating risk of venous and arterial t hrombosis in patients with systemic autoimmune diseases.