[An immunohistochemical study of human atherosclerotic lesion]

Cellular composition of 31 cases of human atherosclerotic lesion was studied by immunohistochemical technique. Specimens were taken from the thoracic and abdominal aortas of necrosis. Four monoclonal antibodies were used to identify cell types. Monocytes/macrophages reacting with anti-Leu-M1 or anti-alpha-1-ACT were found in early lesions and some activated areas such as the peripheral region of bottom of atheromatous plagues of the advanced lesions. Some foamy cells also showed positive to alpha-1-ACT. In addition T lymphocytes reacting with anti-UCHL-1 were detected in the early lesions and some activated areas of advanced plaques, and both types of cells were more common in the early than in the advanced lesions. Other types of leukocytes were scanty in both early and advanced atheromatous lesions. In conclusion, the presence of a variable number of monocytes/macrophages and T lymphocytes in human atherosclerotic lesion may represent a cell-mediated immune response which may be very important in the initiation and progression of atherosclerotic lesion.