The detection of autoantibodies to ATP-binding cassette transporter A1 and its role in the pathogenesis of atherosclerosis in patients with systemic lupus erythematosus

Objectives: To investigate the prevalence of autoantibodies against ATP-binding cassette transporter A1 (ABCA1) in SLE patients, and evaluate the association between anti-ABCA1 autoantibodies and atherosclerosis in SLE. Design and methods: The sera of 75 SLE patients and 75 healthy controls were tested by immunoblotting. Then, we examined the effect of anti-ABCA1 autoantibodies on cholesterol efflux in vitro. Results: The prevalence of anti-ABCA1 antibodies in SLE patients was significantly higher than the controls (p < 0.05). The prevalence in the SLE-plaque group was higher than that in the SLE-non-plaque group (p < 0.05). The IgG purified from anti-ABCA1-antibody positive sera can inhibit cellular cholesterol efflux from THP-1 cells in vitro with a significantly higher inhibition ratio than that of the healthy controls. Conclusions: Our observations suggest that anti-ABCA1 autoantibodies are involved in the pathogenesis of lupus atherosclerosis and that autoantibodies against ABCA1 may act as biomarkers for atherosclerosis in SLE. (c) 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.