EVIDENCE THAT THE DEATH OF MACROPHAGE FOAM CELLS CONTRIBUTES TO THE LIPID CORE OF ATHEROMA

Sections of human atherosclerotic lesions of different stages show tha t, in early lesions, the acellular lipid core is usually immediately a djacent to the deepest edge of a collection of macrophage foam cells. Advanced lesions with a large lipid core have variable numbers of macr ophage foam cells, close to the lateral edges, or shoulders: of the co re. In both early and advanced lesions, some of the macrophages neares t the core appear to be dying. Lipid cores contain two materials which in earlier lesions are found only in macrophages, namely ceroid and C D68 antigen, but do not contain recognisable smooth muscle cell actin, It is concluded that death of macrophage foam cells contributes to th e origin and slow enlargement of the lipid core. The cause of macropha ge death is not yet certain, but is under investigation.