High
LDL-cholesterol (
LDL-C) characterizes
familial hypercholesterolemia (FH) and
familial combined hyperlipidemia (FCH).
LDL-
apheresis, used in these patients to reduce
LDL-C levels, has been shown to also affect HDL levels and composition. We studied
LDL-
apheresis effects on six FH and nine FCH subjects' serum capacity to modulate cellular
cholesterol efflux, an index of HDL functionality, and to load macrophages with
cholesterol. Serum
cholesterol efflux capacity (CEC) and macrophage
cholesterol loading capacity (CLC) were measured before, immediately after, and two days after
LDL-
apheresis. The procedure reduced total
cholesterol (TC),
LDL-C, and
apoB plasma levels (-69%, -80% and -74%, respectively), parameters only partially restored two days later. HDL-C and
apoA-I plasma levels, reduced after
LDL-
apheresis (-27% and -16%, respectively), were restored to almost normal levels two days later.
LDL-
apheresis reduced serum aqueous diffusion (AD) CEC, SR-BI-CEC, and ABCA1-CEC. AD and SR-BI were fully restored whereas ABCA1-CEC remained low two days later. Sera immediately and two days after
LDL-
apheresis had a lower CLC than pre-
LDL-
apheresis sera. In conclusion,
LDL-
apheresis transiently reduces HDL-C levels and serum CEC, but it also reduces also serum capacity to deliver
cholesterol to macrophages. Despite a potentially negative effect on HDL levels and composition,
LDL-
apheresis may counteract foam cells formation.