Spectrophotometric and Electrophoretic Analysis of Carotid Plaque Lipoproteins

Amanda R. Tatro

Determining the number of proteins present in an atherosclerotic plaque and the roles played by these proteins is essential in the future to diagnosis and treatment of atherosclerosis. In vitro plaque protein electrophoresis and in vivo near-IR spectrometry are used to provide qualitative and quantitative information on the proteins involved in carotid atherosclerotic lesions.

The information garnered from electrophoresis is used to test the hypothesis that particular proteins in combination show significant correlation to patient medical history and lesion pathology. For example, bruit, from medical history, and fibrous cap, from pathology reports, are now known to involve similar concentrations of the same proteins. Near-IR spectra of these proteins indicate that all but one are probable lipoproteins.

In addition, the concentration of the 18 kD protein is related to lesion size, which in turn has been related to severity of disease. Duplex ultrasound measurements such as shown below are used to determine lesion size and are compared to protein concentrations determined by electrophoresis to demonstrate a relationship between the concentration of the 18 kD protein and the the size of the lesion.