A study of methods of identification and estimation of Lp(a) lipoprotein and of its significance in health, hyperlipidaemia and atherosclerosis

The Lp(a) lipoprotein was originally suggested to be a qualitative autosomal dominant genetic marker confined to about 35% of Caucasian populations, when these were screened by a gel-diffusion technique. Using a more sensitive and quantitative immunochemical technique, the Lp(a) lipoprotein is found to be detectable in 75% of a random British population and to show quantitative variation in concentration between individuals. In hyperlipidaemic subjects (with the exception of subjects with the Type V abnormality) there is an overall increase in Lp(a) reactivity with a tendency for higher individual values to occur, regardless of the type of hyperlipidaemia. In individuals with coronary heart disease, hypertriglyceridaemia and the presence of a pre-beta-lipoprotein band on electrophoresis, no evidence was obtained to suggest that the electrophoretic abnormality was directly due to the increased frequency of Lp(a) reactivity found in such subjects. Using the immunofluorescent technique, the Lp(a) antigen has been demonstrated in the arterial atherosclerotic lesions of Lp(a) reactors in a topographic distribution closely similar to that of LDL.