Low density lipoprotein immunoapheresis does not increase plasma lipid peroxidation products in vivo

Extracorporeal elimination of low density lipoprotein (LDL) is frequently u sed in drug-resistant hypercholesterolemia. LDL-immunoapheresis selectively removes LDL and lipoprotein(a) [Lp(a)] from plasma. Lipid peroxidation is one unwanted side effect, that occurs during extracorporeal plasma treatmen t. The purpose of this study was to investigate the effect of LDL immunoaph eresis on lipid peroxidation. Before and after a single LDL-immunoapheresis treatment, plasma concentrations of lipid hydroperoxides, determined with two different spectophotometric assays, thiobarbituric acid-reacting substa nces (TBARS), determined spectrophotometrically and malondialdehyde (MDA), determined by an MDA-TBA/HPLC method, were measured in 13 hypercholesterole mic patients. In addition MDA was also determined in the eluate of the aphe resis column. Before treatment, plasma cholesterol and LDL cholesterol conc entrations were significantly higher in patients than in healthy control su bjects, as were the lipid peroxidation products. LDL-immunoapheresis treatm ent of the patients led to significant decreases in total cholesterol (69+/ -8%), LDL-cholesterol (79+/-7%), HDL-cholesterol (35+/-17%), triglycerides (38+/-21%), apolipoprotein-B (77+/-6%), apolipoprotein-Al (25+/-5%) and Lp( a) concentrations (76+/-10%). Changes in plasma lipid peroxide concentratio ns (17+/-8 nmol/l before vs. 14+/-5 nmol/l after treatment) were not signif icant, neither were those in TEARS (3.0+/-2.6 mu mol/l vs. 2.3+/-1.3 mu mol /l) or MDA concentrations (1.03+/-0.17 mu mol/l vs. 1.0+/-0.20 mu mol/l). P atients with high baseline values showed a decrease, whereas others did not . MDA was present (0.57+/-0.13 mu mol/l) in the eluate of the apheresis col umn, suggesting that, along with LDL, lipid peroxidation products are also removed. From these results we conclude that a single LDL-immunoapheresis t reatment effectively reduces LDL, and Lp(a) in the absence of increases in plasma lipid peroxidation products. (C) 1999 Elsevier Science B.V. All righ ts reserved.