INCREASED LEVELS OF AUTOANTIBODIES TO CARDIOLIPIN AND OXIDIZED LOW-DENSITY-LIPOPROTEIN ARE INVERSELY ASSOCIATED WITH PLASMA VITAMIN-C STATUS IN CIGARETTE SMOKERS

In this study we have measured circulating levels of autoantibodies to cardiolipin and oxidised low-density lipoprotein (ox-LDL) and correla ted these with plasma concentrations of the anti-oxidant nutrients vit amin C, vitamin E and beta-carotene, in a group (79) of asymptomatic, male cigarette smokers and in non-smoking control subjects. Cigarette smoking, a well-known risk factor for development of atherosclerosis, was found to be associated with moderately elevated levels of autoanti bodies to both cardiolipin and ox-LDL. Increased levels of these autoa ntibodies were most evident in the older smokers (> 30 years) and were significantly and inversely corrrelated wtih plasma vitamin C, but no t with vitamin E or beta-carotene. Absorption studies designed to inve stigate the specificity of these autoantibodies demonstrated a high de gree of cross-reactivity of cardiolipin antibodies with ox-LDL, while antibodies to the oxidatively modified lipoprotein tended to be specif ic for this antigen. These findings suggest that cigarette smoking pro motes formation of autoantibodies to both cardiolipin and ox-LDL and t hat these may be involved in the initiation and/or perpetuation of ath ersclerosis. Dietary intake of vitamin C may be a determinant of susce ptibility to development of this cardiovascular disorder.