Reversible abnormalities of low density lipoprotein composition in familial hypercholesterolaemia

Abstract

Low density lipoprotein (LDL) composition was analyzed in 21 patients with familial hypercholesterolemia, including 6 homozygotes. By comparison with 19 controls, the patients'' LDL had an increased ratio of cholesterol:phospholipid and a decreased ratio of lecithin:sphingomyelin; these changes were more marked in homozygotes than in heterozygotes. Treatment of 7 patients with plasma exchange temporarily resulted in near-normalization of the composition of their LDL. Abnormalities of LDL composition in familial hypercholesterolemia may be secondary to hypocatabolism of LDL, which prolongs the half-life of LDL and thus increases the mean age of the population of particles circulating in plasma.