title: Contact activation in low-density lipoprotein apheresis systems.
abstract: BACKGROUND
  Anaphylactoid reactions due to contact activation have been observed in patients on ACE inhibitor therapy and hemodialysis with negatively charged dialysis membranes. Negatively charged surfaces are functional constituents of different LDL apheresis systems. Therefore, contact activation was investigated during LDL apheresis with three different systems: (i) heparin-induced extracorporeal LDL precipitation (HELP); (ii) dextran sulfate cellulose (DSC) columns; and (iii) modified polyacrylate gels (DALI) in a clinical setting.
  
  
  METHODS
  24 prevalent patients on regular LDL apheresis treatment were included in the study. Bradykinin, prekallikrein, and HMW kininogen were measured during a single LDL apheresis at different sites of the systems.
  
  
  RESULTS
  LDL apheresis with DSC and DALI was associated with an extreme release of bradykinin after the passage of plasma or blood through the LDL adsorbers as well as with a decrease of prekallikrein and HMW kininogen during the course of the treatment. Bradykinin release exceeded the degradation capacity of the kininase II, since markedly elevated bradykinin concentrations were observed in the arterial line of the extracorporeal circuits of both systems. This was not associated with anaphylactoid reactions. In contrast to the treatments with DSC and DALI, the HELP system did not lead to any activation of the kallikrein-kinin system.
  
  
  CONCLUSIONS
  From our data we conclude that angiotensin converting enzyme (ACE) inhibitors are contraindicated in patients on LDL apheresis with the DSC and the DALI system. Because the HELP system does not activate the kallikrein-kinin system, patients who need ACE inhibitors are predisposed for this LDL apheresis procedure.
authors.affiliation: Department of Nephrology, University of Würzburg, Würzburg, Germany. krieter_d@klinik.uni-wuerzburg.de
authors.forename: Detlef H
authors.initials: DH
authors.lastname: Krieter
authors.forename: Jörn
authors.initials: J
authors.lastname: Steinke
authors.forename: Markus
authors.initials: M
authors.lastname: Kerkhoff
authors.forename: Edwin
authors.initials: E
authors.lastname: Fink
authors.forename: Horst-Dieter
authors.initials: HD
authors.lastname: Lemke
authors.forename: Christine
authors.initials: C
authors.lastname: Zingler
authors.forename: Gerhard A
authors.initials: GA
authors.lastname: Müller
authors.forename: Peter
authors.initials: P
authors.lastname: Schuff-Werner
mesh_terms: D000180:Acrylic Resins; D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D001781:Blood Component Removal / Q000379:methods*; D001920:Bradykinin / Q000097:blood; D002482:Cellulose; D011232:Chemical Precipitation; D008078:Cholesterol, LDL / Q000097:blood / Q000302:isolation & purification*; D016264:Dextran Sulfate; D005112:Extracorporeal Circulation; D005260:Female; D005782:Gels; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D019679:Kininogen, High-Molecular-Weight / Q000097:blood; D008297:Male; D008875:Middle Aged; D007703:Peptidyl-Dipeptidase A / Q000097:blood; D010952:Plasma Substitutes; D011288:Prekallikrein / Q000032:analysis
chemical_list: D000180:Acrylic Resins; D000925:Anticoagulants; D008078:Cholesterol, LDL; D005782:Gels; D019679:Kininogen, High-Molecular-Weight; D010952:Plasma Substitutes; C006903:carbopol 940; D002482:Cellulose; D006493:Heparin; D016264:Dextran Sulfate; D011288:Prekallikrein; D007703:Peptidyl-Dipeptidase A; D001920:Bradykinin