title: Biocompatibility of cellulosic and synthetic membranes assessed by leukocyte activation.
abstract: OBJECTIVE
  The contact of blood with artificial surfaces may activate blood leukocytes and platelets and initiate the leukocyte inflammatory response. We have investigated the effect of a hemodialysis (HD) with a cellulosic- and a synthetic-based membrane on circulating leukocyte activation.
  
  
  METHODS
  Samples were obtained from patients with ESRD at baseline, and at 15 and 120 min of a hemodialysis session from both the arterial and venous lines. Leukocyte respiratory burst was analyzed by luminol chemiluminescence. Actin polymerization, expression of CD11b, and heterotypic aggregation were studied by flow cytometry, leukocyte labeling with NBD phallacidin and monoclonal antibodies, respectively.
  
  
  RESULTS
  HD with a cellulosic membrane induced a transient fall in neutrophil (1.2 +/- 0.5 x 10(9) vs. 3.6 +/- 0.6 x 10(9) cells/l; p < 0.05) and monocyte counts (0.2 +/- 0.1 x 10(9) vs. 0.7 +/- 0.1 x 10(9) cells/l; p < 0.05). There was also an increase in respiratory burst in the venous line during a HD with a cellulosic membrane, at 15 and 120 min (100 +/- 41 and 143.2 +/- 45.3 vs. 23.8 +/- 15.7; p < 0.05). Polymerized actin, expressed as fluorescence arbitrary units, was increased in baseline samples from uremic patients versus control subjects (327.8 +/- 60.8 for a cellulosic membrane, p < 0.005, and 205 +/- 26.5 for a synthetic one, p < 0.05 vs. 97.8 +/- 27.6 in controls). The percentage of CD11b+ cells increased in samples during a HD with a cellulosic membrane at the venous line at 15 and 120 min (9.6 +/- 4.5 and 18.4 +/- 7.1% vs. 3.3 +/- 1.9%; p < 0.05%). Changes in heterotypic aggregation during HD did not reach statistical significance, but levels were higher in patients treated with a cellulosic membrane at all points than in patients dialyzed with a synthetic one.
  
  
  CONCLUSIONS
  There is evidence of a priming state of leukocytes from uremic patients, which is more evident in patients dialyzed with a cellulosic membrane. Cellulosic membranes also induce greater leukocyte activation than synthetic membranes during hemodialysis.
authors.affiliation: Servei d'Hemoteràpia i Hemostàsia, Hospital Clínic i Provincial, Barcelona, Spain. mherman9@pie.xtec.es
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Hernández
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Galán
authors.forename: Aleix
authors.initials: A
authors.lastname: Cases
authors.forename: Jose
authors.initials: J
authors.lastname: Lopez-Pedret
authors.forename: Arturo
authors.initials: A
authors.lastname: Pereira
authors.forename: Raul
authors.initials: R
authors.lastname: Tonda
authors.forename: Jordi
authors.initials: J
authors.lastname: Bozzo
authors.forename: Gines
authors.initials: G
authors.lastname: Escolar
authors.forename: Antonio
authors.initials: A
authors.lastname: Ordinas
mesh_terms: D000328:Adult; D000368:Aged; D001672:Biocompatible Materials; D002482:Cellulose; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy; D007962:Leukocytes / Q000502:physiology*; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D006435:Renal Dialysis; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D008567:Membranes, Artificial; D002482:Cellulose