Anti-annexin II antibodies in systemic autoimmune diseases and antiphospholipid syndrome.

Objectives: The objective of this study were (1) to evaluate the prevalence of anti-annexin II antibodies in patients with various autoimmune diseases and antiphospholipid syndrome and (2) to correlate anti-annexin II antibodies with anti-phospholipid antibodies.

Materials And Methods: Anti-annexin II antibodies and anti-phospholipid were detected, using an enzyme-linked immunosorbent assay, in the serum of patients with primary antiphospholipid syndrome (n = 16), systemic lupus erythematosus (n = 53), primary Sjögren syndrome (n = 71), systemic sclerosis (n = 17), systemic vasculitis (n = 18), and rheumatoid arthritis (n = 119). Healthy blood donors (n = 99) were used as controls.

Results: Anti-annexin II antibodies were significantly more prevalent in patients with connective tissue diseases (8.5%), especially antiphospholipid syndrome (14.8%) and rheumatoid arthritis (10%), than in controls (2%). An inverse correlation was observed between anti-annexin II antibodies and antiphospholipid antibodies.

Conclusion: Annexin II can be recognized by antibodies in serum from patients with systemic autoimmune disorders. Further studies are required to determine the clinical significance of anti-annexin II antibodies in rheumatoid arthritis and to determine their diagnostic value in discriminating clinical subgroups of patients with antiphospholipid syndrome.