title: Effect of the hemodialysis membrane on the inflammatory reaction in vivo.
abstract: BACKGROUND
  Increased levels of C-reactive protein (CRP), a marker of systemic inflammation, are associated with myocardial infarction, stroke and the development of peripheral arterial disease. Hemodialysis patients show signs of an inflammatory reaction indicated by elevated plasma levels of CRP and by increased plasma levels of interleukins.
  
  
  METHODS
  To investigate the effect of the dialysis membrane on the inflammatory reaction, we conducted a randomized study in 18 hemodialysis patients. Patients were subsequently treated with dialyzers containing polyamide, polycarbonate or cuprophan for 8 weeks on each dialyzer in a crossover design. During each treatment period, CRP plasma levels were measured 6 times at weekly intervals. The total content and the spontaneous and lipopolysaccharide- (LPS) stimulated production of interleukin-1beta (IL-1beta), IL-6 and IL-1 receptor antagonist (IL-1Ra) were determined in whole blood samples.
  
  
  RESULTS
  CRP plasma levels were significantly higher in hemodialysis patients (all patients, 1.63 +/- 0.23 mg/dl) compared to normals (0.14 +/- 0.02 mg/dl, p < 0.0001). CRP levels were lower when patients were dialyzed with polyamide (1.19 +/- 0.18 mg/dl) compared to the levels when the same patients were dialyzed with cuprophan (1.77 +/- 0.37 mg/dl, p = 0.02) or with polycarbonate (1.34 +/- 0.2 mg/dl, n.s). The whole blood content of IL-1Ra in non-incubated samples was significantly lower in normal subjects (512 +/- 60 pg/ml) compared to hemodialysis patients (980 +/- 80 pg/ml, p < 0.01). The whole blood content of IL-1Ra was higher when patients were dialyzed with cuprophan (1,062 +/- 119 pg/ml) compared to the same patients on polyamide (906 +/- 78 pg/ml, p < 0.05) or on polycarbonate (973 +/- 80 pg/ml, n.s.). Spontaneous and LPS-induced production of IL-1beta and IL-6 was similar for all dialyzers.
  
  
  CONCLUSIONS
  We conclude that the inflammatory reaction in hemodialysis patients is affected by the choice of the dialyzer.
authors.affiliation: Department of Nephrology and Internal Intensive Care Medicine, University Clinic Charité, Campus Virchow-Klinikum, Humboldt University, Berlin, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Schindler
authors.forename: O
authors.initials: O
authors.lastname: Boenisch
authors.forename: C
authors.initials: C
authors.lastname: Fischer
authors.forename: U
authors.initials: U
authors.lastname: Frei
mesh_terms: D001672:Biocompatible Materials; D002097:C-Reactive Protein / Q000378:metabolism*; D002482:Cellulose / Q000031:analogs & derivatives; D018592:Cross-Over Studies; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007249:Inflammation / Q000209:etiology* / Q000276:immunology; D007378:Interleukins / Q000097:blood; D007674:Kidney Diseases / Q000276:immunology / Q000628:therapy; D008567:Membranes, Artificial; D008875:Middle Aged; D009757:Nylons; D011076:Polycarboxylate Cement; D011446:Prospective Studies; D006435:Renal Dialysis / Q000295:instrumentation*; D013997:Time Factors
chemical_list: D001672:Biocompatible Materials; D007378:Interleukins; D008567:Membranes, Artificial; D009757:Nylons; D011076:Polycarboxylate Cement; C005506:polycarbonate; D002482:Cellulose; D002097:C-Reactive Protein; C009865:cuprammonium cellulose