SAT0167 Antibodies against oxidized but not non-oxidized cardiolipin and phosphatylserine have atheroprotective properties in SLE

Background Atherosclerosis is an inflammatory disease, and the major cause of cardiovascular disease (CVD) including stroke, myocardial infarction (MI) and claudication. In systemic lupus erytheatosus (SLE), the risk of CVD is raised as compared to healthy controls and a combination of traditional and non-traditional risk factors appear to account for this1. Even though it is possible that other factors related to thrombosis contribute more to CVD in SLE than in the general population, increased prevalence of atherosclerotic plaques is associated with CVD also in SLE1. This finding has been confirmed in several case-control studies 1-4. Objectives We here determine the role of antibodies against oxidized cardiolipin and phosphatidylserine (anti-OxCL and anti-OxPS) in SLE. Methods Patients with SLE (n=114) were compared with age- and sex-matched population-based controls (n=122). Common carotid intima-media thickness (IMT) and plaque occurrence were determined by B-mode ultrasound. Plaques were graded according to echogenicity and grouped as 1-4, with 1 being echoluscent, and considered most vulnerable. Antibodies were studied by ELISA. Results Prevalence of low IgM anti-OxPS (but not anti-OxCL) levels (below 33rd percentile) was increased in SLE (p=0.037). SLE-patients with atherosclerotic plaques had lower IgM anti-OxCL (p=0.031) and anti-OxPS (0.0034) and after adjusting for other risk factors (age, hyperlipidemia, hypertension and glucose), low anti-OxPS remained significant (p=0.028). Vulnerable plaques (total, or left side) were more prevalent among SLE-patients with low IgM anti-OxCL and anti-OxPS IgM aCL when controlled for other factors (p