A number of pathological eonditions, including chronic inflammation, generate conditions where low density lipoprotein (LDL) suffers oxidative, chemical and biological changes, thus producing modified LDL particles (mLDL).These LDL products are involved in the pathogenesis of atherosclerosis.Different mLDL components are biologically active and one of its main features is to interact with immune system cells and induce an antibody mediated immune response.This response could be beneficial for the individual (i.e.protect against the deleterious effects of mLDL) or induce an autoimmune response against mLDL, producing pathological changes in the patient.Advances in the understanding of mLDL pathophysiological properties and the possibility of using patient antibodies as biomarkers in the detection, evaluation, diagnosis and follow-up of atherosclerosis will be discussed in this presentation.