STATE-OF-THE-ART OF LIPID APHERESIS

Currently, 5 different lipid apheresis procedures are available for ro utine clinical treatment of hypercholesterolemic patients. Unselective plasma exchange is a technically simple extracorporeal circuit, but a lbumin substitution fluid must be used and there is no high-density li poprotein (HDL) recovery. Semiselective double filtration with improve d size selectivity because of a small-pore secondary filter combines g ood elimination of low-density lipoprotein (LDL), lipoprotein (a) (Lp[ a]), and fibrinogen with adequate HDL recovery; modifications such as thermofiltration, predilution/backflush, or pulsatile flow have been p roposed for the improvement of this system. Three highly selective pro cedures are based on immunologic or electrostatic interactions: immuno adsorption using anti-low-density lipoprotein (LDL) antibodies, chemoa dsorption onto dextran sulfate, and heparin-induced LDL precipitation (HELP) apheresis. The features of each system are discussed critically . Lastly, two new developments, Lp(a) immunoadsorption and LDL hemoper fusion using a polyacrylate LDL adsorber compatible with whole blood, are described.