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.
Keywords
anti-PON1 antibodies - anti-HDL antibodies - anti-oxidant activity - intima-media
thickness - atherosclerosis
