title: Lipid apheresis by hemoperfusion: in vitro efficacy and ex vivo biocompatibility of a new low-density lipoprotein adsorber compatible with human whole blood.
abstract: To date, selective extracorporeal low-density lipoprotein (LDL) removal can only be performed from plasma; that is, a plasma-cell separation step using a centrifuge or a plasma membrane separator is necessary initially. This article characterizes a new polyacrylate-based LDL adsorber directly applicable to whole blood. In vitro single-pass hemoperfusion tests using pooled donor blood showed quantitative adsorption of atherogenic LDL-cholesterol (LDL-C) and complete recovery of protective high-density lipoprotein C. Fibrinogen, another independent risk factor of atherosclerosis, was also adsorbed to a lesser extent. Single-pass ex vivo biocompatibility using fresh donor blood on-line was excellent and resulted in minimal cell loss. Neither signs of hemolysis nor activation of monocytes (interleukin-1 production) were detected. Only slight activation of leukocytes (elastase release) and thrombocytes (platelet factor 4 secretion) as well as of coagulation (thrombin-antithrombin complex formation) and complement (C3a, C5a generation) was observed. Under the experimental conditions used, the optimal anticoagulation regimen was 0.5 IU heparin plus 0.375 mg citrate/ml blood. Priming the column with a buffer of pH 7.4 containing heparin, citrate, and Ca2+ is recommended. In conclusion, this new adsorber exhibited selective LDL-C adsorption in vitro combined with excellent ex vivo biocompatibility and thus holds great promise for a successful clinical application in a closed-loop system in patients.
authors.affiliation: Nephrological Department, Klinikum Grosshadern, University of Munich, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Bosch
authors.forename: B
authors.initials: B
authors.lastname: Schmidt
authors.forename: M
authors.initials: M
authors.lastname: Blumenstein
authors.forename: H J
authors.initials: HJ
authors.lastname: Gurland
mesh_terms: D000180:Acrylic Resins; D000327:Adsorption; D001672:Biocompatible Materials; D001777:Blood Coagulation / Q000187:drug effects; D001781:Blood Component Removal / Q000379:methods*; D002951:Citrates / Q000494:pharmacology; D019343:Citric Acid; D006464:Hemoperfusion / Q000379:methods*; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood*
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials; D002951:Citrates; D008077:Lipoproteins, LDL; D019343:Citric Acid; D006493:Heparin