title: Heparin extracorporeal LDL precipitation (HELP): an effective apheresis procedure for lowering Lp(a) levels.
abstract: Heparin-induced extracorporeal low-density lipoprotein precipitation (HELP) is based on the precipitation of apolipoprotein B (apo B) containing lipoproteins with heparin at low pH (4.85). In in vitro experiments we could show that Lp(a) is quantitatively (> 99%) precipitated from plasma by heparin in the pH range 4.6-5.2. The acute changes in Lp(a) after a single HELP-LDL apheresis were investigated in twelve patients with Lp(a) concentrations > 30 mg/dl. A single treatment caused a highly significant decrease (62%) in the concentration of Lp(a), similar to the decrease (60%) observed for LDL-cholesterol. Analysis of the data from ten patients with different apo(a) phenotypes indicated that Lp(a) is eliminated with almost 100% efficiency in the extracorporeal circulation, irrespective of apo(a) phenotype and plasma concentration. The mean rate of recovery of Lp(a) following HELP-LDL apheresis was slightly slower than that of LDL-cholesterol. Plasma Lp(a) concentrations were monitored in seven patients over 2 years. Mean Lp(a) concentrations after 2 years were lower than pre-treatment levels, indicating that repeated elimination of the lipoprotein does not lead to an induction in its synthesis. HELP-LDL apheresis should be particularly suitable for treatment of patients with elevated LDL-cholesterol levels who are also at increased coronary risk because of high Lp(a) concentrations.
authors.affiliation: Department of Clinical Chemistry, Georg-Augustus University, Goettingen, Germany.
authors.forename: V W
authors.initials: VW
authors.lastname: Armstrong
authors.forename: P
authors.initials: P
authors.lastname: Schuff-Werner
authors.forename: T
authors.initials: T
authors.lastname: Eisenhauer
authors.forename: M
authors.initials: M
authors.lastname: Helmhold
authors.forename: M
authors.initials: M
authors.lastname: Stix
authors.forename: D
authors.initials: D
authors.lastname: Seidel
mesh_terms: D001053:Apolipoproteins / Q000235:genetics / Q000378:metabolism; D053241:Apoprotein(a); D001161:Arteriosclerosis / Q000517:prevention & control; D001781:Blood Component Removal / Q000379:methods*; D011232:Chemical Precipitation; D008078:Cholesterol, LDL / Q000097:blood / Q000302:isolation & purification; D006493:Heparin; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006938:Hyperlipoproteinemia Type II / Q000097:blood / Q000235:genetics / Q000628:therapy; D007700:Kinetics; D017270:Lipoprotein(a) / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood / Q000302:isolation & purification*; D010641:Phenotype
chemical_list: D001053:Apolipoproteins; D008078:Cholesterol, LDL; D017270:Lipoprotein(a); D008077:Lipoproteins, LDL; D006493:Heparin; D053241:Apoprotein(a)