Serum Levels of Anti-PON1 and Anti-HDL Antibodies as Potential Biomarkers of Premature Atherosclerosis in Systemic Lupus Erythematosus.

Abstract

The present study aimed to evaluate the possible role of immunoglobulin G (IgG) antibodies against high-density lipoproteins (HDL) and paraoxonase 1 (PON1) as possible biomarkers of cardiovascular disease (CVD) in systemic lupus erythematosus (SLE). To this end, levels of these autoantibodies, PON1 activity and total antioxidant capacity were quantified in serum samples from 198 SLE patients, 100 healthy controls (HC) and 42 non-autoimmune individuals with traditional cardiovascular risk factors. PON1 rs662 polymorphism was analysed in a subgroup of patients and controls. Subclinical CVD were determined by Doppler ultrasound in 118 SLE patients and 30 HC, analysing carotid intima-media thickness (IMT) and blood flow parameters in internal carotid, middle cerebral and basilar arteries. Serum levels of both anti-HDL and anti-PON1 antibodies were increased in SLE patients compared with HC (p < 0.001); however, only anti-PON1 antibodies, in addition to disease activity, were significant predictors of the impaired PON1 function in SLE (β = -0.143, p = 0.045). Conversely, anti-HDL antibodies were associated with higher risk of CVD (odds ratio: 3.69; p = 0.012) and lower HDL levels at disease onset (ρ = -0.324, p = 0.044). Finally, anti-PON1 antibodies were associated with carotid IMT in SLE (β = 0.201, p = 0.008) and inversely related to cranial arteries blood flow velocities in patients with clinical and subclinical CVD (all p < 0.001). In sum, these findings allowed us to propose serum levels of anti-PON1 and anti-HDL antibodies as potential early biomarkers of endothelial damage and premature atherosclerosis in SLE, thus constituting useful therapeutic targets for the prevention of future CVD in these patients.