Anti-phospholipid antibody prevalence and association with subclinical atherosclerosis and atherothrombosis in the general population

Background: There is no agreement on the prevalence of anti-phospholipid antibodies (aPLs) and the correlation with atherosclerosis and cardiovascular (CV) events in the general population. Methods: We performed a cross-sectional study on 1712 randomly enrolled subjects from a Northern Italian city to investigate the presence of aPLs and the association with subclinical atherosclerosis (using the carotid artery intima media thickness measured as inter-adventitia common carotid artery diameters - ICCAD) and retrospectively collected CV factors and events (i.e. acute myocardial infarction, stroke, and peripheral obliterans arterial vasculopathy) using physician-assisted questionnaires. We tested serum IgG, IgM, and IgA anti-cardiolipin, anti-beta2glycoprotein I (aGPI), and anti-phosphatidylserine-prothrombin antibodies. Results: Positive aPLs were found in 15.1% of the subjects, with no differences between sex but with higher rates in older subjects. Carotid subclinical atherosclerosis was more frequent in aPL positive subjects; more specifically, aGPI IgA were associated with higher ICCAD average (adjusted beta 0.51, 95% confidence interval (CI)0.17–0.84; p = 0.003). A positive history of CV events was also more frequent in aPL positive subjects (odds ratio (OR) 1.67, 95%CI 1.08–2.54; p = 0.012), particularly peripheral obliterans arterial vasculopathy (OR 2.02; 95%CI 1.14–3.57; p = 0.015). Among subjects with a Framingham risk score >20, and/or diabetes, and/or body mass index >35 kg/m2, aPL positivity was associated to the highest risk of CV events (OR 2.52, 95%CI 1.24–5.11; p = 0.011). Conclusions: APL prevalence in the general population is higher than previously reported. CV events and subclinical atherosclerosis are more frequent in the presence of aPL, particularly when a high CV risk coexists.