The Effects of LDL-Apheresis and Plasma Exchange on Cholesterol Level and Lipid Composition of Low and High Density Lipoproteins in Homozygous Patients with Familial Hyper-Cholesterolemia

Abstract

The low plasma HDL concentration and cholesterol-rich LDL may play a role in the early onset of atherosclerosis in homozygous patient with familial hypercholesterolemia. We studied effects of plasma exchange and LDL-apheresis on cholesterol levels and lipid composition of LDL and HDL in two patients with homozygous FH (SY and YS). In case SY, plasma exchange (1/2wks) and LDL-apheresis (2/1wk) caused a decrease of LDL concentration (p<0.01) and an increase of HDL concentration (p<0.05). Cholesterol content (%) of LDL decreased from 56.7±0.9% to 53.2±0.6% by LDL-apheresis (2/1wk)(p<0.05). TC/PL mass ratio decreased from 1.690±0.036 to 1.530±0.025 (p<0.02). In case YS, LDL-apheresis caused a decrease in cholesterol content (%) of LDL and HDL, and an increase in phospholipid content (%) of HDL. The differences between HDL-cholesterol levels measured by ultracentrifugation and precipitation (Heparin-Ca) methods, decreased after LDL-apheresis treatments. HDL with apo E also examined by an immunoblotting method using human apo E anti-serum. Homozygous FH serum showed a darker band of HDL with E than a normal serum by agarose gel electrophoresis and immunoblot. The band of apo E thinned after LDL-apheresis.
These results indicated that LDL lowering by LDL-apheresis and plasma exchange may cause an increase of HDL concentration and a decrease of cholesterol content (%) in LDL and HDL. In addition, the remove of HDL with E by LDL-apheresis may activate a reverse cholesterol transport system.