Annexin A5 as Independent Predictive Biomarker for Subclinical Atherosclerosis and Endothelial Dysfunction in Systemic Lupus Erythematosus Patients

Abstract

Increased atherosclerosis prevalence in patients with systemic lupus erythematosus (SLE) is an epidemiological certainty. SLE patients are linked to endothelial immune conflict, chronic inflammation antiphospholipid antibodies, and high serum annexin A5 levels. Many of these factors belong to the inflammatory cascade which is common to both SLE and ATS. Therefore, there is an overlap between traditional and nontraditional atherosclerosis risk factors in SLE patients. The purpose of the study was to determine the association of conventional cardiovascular risk factors and atherosclerosis characteristics with biomarkers that are known to be implied in atherogenesis in SLE patients. In this study subclinical atheroscler is was evaluated by'carotid intima-medial thickness (IMT) and endothelial dysfunction by flow mediated dilation (FMD) in both SLE patients and controls. 132 SLE patients were recruited: 32 patients were assigned to the atherosclerosis group (ASLE, mean age +/- standard deviation 42.16 +/-9.18 years) and 100 were assigned to non-atherosclerosis group (nASLE, mean age 41.54 +/- 11.79 years). 50 healthy controls were enrolled (control group, mean age 41.4 +/- 11 years). Annexin A5 levels, anti phosphatidyl serine, and anti oxidized LDL antibodies were measured by enzyme-linked immunosorbent assay in both patients and healthy controls. Mean IMT in all SLE patients (0.83 - 0.11 mm) was significantly higher when compared to controls (0.66 +/- 0.04 mm, p < 0.05); mean FMD was significantly smaller in SLE patients (2.98 +/- 1.58%) when compared to controls (10.83 +/- 2.02%, p < 0.05). When all SLE patients and controls were considered together, SLIC presence, body mass index, serum annexin A5 levels, history of hypertension, and age were found to be independent predictors for abnormal IMT. In the SLE group only age and serum annexin A5 levels were found to be independent predictors for IMT. When all SLE patients were considered together, serum annexin A5 and age were found as independent predictors of FMD. In both ASLE and nASLE groups, age and serum annexin A5 levels were found to be independent predictive variables for endothelial dysfunction. This study confirms the presence of both endothelial dysfunction and subclinical atherosclerosis in SLE patients and suggests serum annexin A5 as predictive biomarker for subclinical atherosclerosis in SLE patients.