Lipid Apheresis by Hemoperfusion: In Vitro Efficacy and Ex Vivo Biocompatibility of a New Low‐Density Lipoprotein Adsorber Compatible with Human Whole Blood

: 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-l 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 citratelml 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 LDLC 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.