Effects of autoimmune antibodies anti-lipoprotein lipase, anti-low density lipoprotein, and anti-oxidized low density lipoprotein on lipid metabolism and atherosclerosis in systemic lupus erythematosus.

INTRODUCTION: Premature development of atherosclerosis in systemic lupus erythematosus has been widely reported. Anti-lipoprotein lipase antibody may be one cause contributing to this disorder.

OBJECTIVE: To assess the extent of coronary risk due to autoimmune antibodies in terms of carotid plaque in lupus patients.

PATIENTS AND METHODS: We compared 114 documented lupus patients with 111 normal controls matched for sex and age. Anti-lipoprotein lipase (A-LPL), anti-oxidized low density lipoprotein (A-OXLDL), and anti-low density lipoprotein (A-LDL) were measured by enzme-linked immunoabsorbent assay. Low density lipoprotein-triglyceride (LDL-Trig) and high density lipoprotein-triglyceride (HDL-Trig) were also measured. Plaque was measured by bilateral carotid ultrasound.

RESULTS: 45.6% of patients tested positive for A-LPL, and 34.4% for A-OXLDL. 44% of normal controls tested positive for A-LPL, and 20% for A-OXLDL. Risk increased sharply in subgroups with increased antibody levels. Patients with A-LPL and A-OXLDL > 0.40 (n = 12) showed coronary risk correlations of: A-LPL x LDL-Trig = 0.7008, P = 0.0111; bilateral ultrasound vs total cholesterol = 0.62205, P = 0.0308; LDL-Trig vs myocardial infarction (MI) = 0.76562, P = 0.0037; total triglycerides vs MI = 0.78191, P = 0.0027); LDL-Trig/LDL-cholesterol vs MI = 0.80493, P = 0.0016; A-OXLDL vs USBL = 0.71930, P = 0.0084. Correlations of SLEDAI with risk variables were highly significant only in subgroups of elevated antibody levels (SLEDAI x A-OXLDL = 0.70366, P = 0.0107).

CONCLUSION: A-LPL initiates the development of LDL mutations, followed by antibody production, plaque formation and coronary risk in some SLE patients.