Noninvasive Imaging of "Technetium-labeled Low Density Lipoprotein Uptake by Tendon Xanthomas in Hypercholesterolemic Patients

Technetium-labeled low density llpoprotelns (Tc-LDL) appear to be useful for describing LDL blodlstribution In normal and dysllpldemlc sub|ects. We Injected T c L D L Into subjects with large tendon xanthomas secondary to homozygous familial hypercholesterolemia or sttosterolemla. Rapid (4 hours) accumulation of Tc-99m activity In xanthomas was observed, and this accumulation Increased over a 24-hour period. No comparable accumulations of Tc-99m activity were noted In normal subjects or in a subject with heterozygous familial hypercholesterolemla who had very small tendon xanthomas. These findings support previous biopsy data Indicating active uptake of LDL by macrophages within xanthoma and suggest that T c L D L Imaging of xanthomas may be useful In studies of the effects of diet and drugs on the accumulation of llpoprotelns by atherosclerotic plaques. (Arteriosclerosis 10:256-262, March/April 1990)