Plasma annexin A5, anti-annexin A5 antibodies and annexin A5 polymorphism in Egyptian female patients with systemic lupus erythematosus and antiphospholipid syndrome

Abstract

Background: Annexin A5 exhibits anticoagulant properties that appear to be defective in patients with antiphospholipid syndrome (APS) resulting in repeated thrombosis and recurrent pregnancy loss (RPL). APS occurs frequently in association with systemic lupus erythematosus (SLE). The present study aimed to find out a possible relationship between annexin A5 (gene polymorphism, antibodies or plasma level) and the pathophysiology of SLE, APS and RPL.

Methods: 47 female patients divided into 3 groups (SLE, APS and RPL) and 20 healthy controls are included in the study. Detection of annexin A5 (-1C/T) gene polymorphism was done by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) assay. Anti-annexin A5 antibodies (IgG and IgM) and annexin A5 plasma level were measured by Enzyme Linked Immunosorbent Assay (ELISA).

Results: The frequency of annexin A5 (-1C/T) polymorphism was significantly higher in SLE related groups (p = 0.02), but it did not correlate with RPL (p = 0.57) or annexin A5 level (p = 0.5). Anti-annexin A5 IgM level was significantly higher among APS patients and was associated with RPL (p = 0.005, odds ratio = 23.75, 95% confidence interval = 2.15 - 262.48).

Conclusions: Annexin A5 (-1C/T) gene mutation may play a role in the pathophysiology of SLE. Anti-annexin A5 IgM was the antibody associated with RPL in this group of APS patients. Annexin A5 plasma levels are not affected by the presence of annexin A5 (-1C/T) polymorphism.