Clinical significance of anti-annexin V antibody in acute cerebral ischemia

Background: Antiphospholipid antibodies (aPLs) are associated with vascular occlusive events. Lupus anticoagulant (LA) and anticardiolipin antibody (aCL) are two aPLs commonly used for screening test. However, other aPLs are reported to play a role in the thrombotic events in other disorders, especially autoimmune disease. We investigated the clinical significance of the anti-annexin V antibody (aAV) in patients with acute cerebral ischemia; annexin V promotes anticoagulant activity via inhibition of prothrombin activation. Methods: A total of 187 patients with acute cerebral infarction or transient ischemic attack, and 66 control subjects were included in this prospective study. IgG type aAV was determined by enzyme-linked immunosorbent sandwich assay in the patient and control groups. The presence of LA and aCL were determined in the patient group using the usual screening method. Results: IgG aAV was detected in 26 of the 187 patients (13.9%), but only in three of the 66 control subjects (4.5%; P = 0.043). Among the 26 aAV positive patients, only five patients were positive for LA or aCL. The presence of IgG aAV was significantly associated with acute cerebral ischemia: one stroke event (OR, 4.39; 95% CI, 1.21-16.01), and two or more stroke events (OR, 3.91; 95% CI, 1.09-14.07). Conclusion: IgG aAV was detected in a significant percentage of the patients with acute cerebral ischemia compared with the control group. The presence of IgG aAV did not usually coincide with LA or aCL. Thus aAV should be considered as a possible associated factor for acute cerebral ischemia.