Implications for the Pathogenesis of Atherosclerosis

Introduction Atherosclerosis The term, atherosclerosis, as it was originally coined by Thoma in 1886, was devised to describe a degenerative process involving the progressive hardening of the blood vessel wall. Today we have advanced to the understanding that the ultimate atherosclerotic lesion is a complex and heterogeneous arrangement of rapidly proliferating and migrating cells that produce and support an active connective tissue matrix. Two major forms of atherosclerotic lesions have been described: the fatty streak and the fibrous plaque. Classic fatty streaks are raised, narrow, yellowed lesions that extend in the direction of blood flow. They are nonobstructive and are likely, but yet unproven, precursors of more advanced lesions. The streaks are characterized by subendothelial collections of foam cells, smooth muscle cells (SMC), T-lymphocytes, and an extracellular matrix of lipid, collagen, elastin, and proteoglycan.-Monoclonal antibody studies have shown that foam cells are primarily monocyte-derived macrophages and occasionally SMC that have imbibed cholesterol and cholesterol esters.