title: Looking beyond endotoxin: a comparative study of pyrogen retention by ultrafilters used for the preparation of sterile dialyis fluid.
abstract: Sterile single-use ultrafilters are used in dialysis for the preparation of the substitution fluid given to patients undergoing dialysis treatments with high convective fluid removal. The retention of pyrogenic agents by the ultrafilters is crucial to avoiding inflammatory responses. The performance of a new single-use ultrafilter (NUF) with a positively charged flat sheet membrane of relatively small membrane area and large pore size was compared to a reference ultrafilter (RUF) with a hollow fiber membrane. Filter performance was tested with various pyrogen-contaminated dialysis fluids by direct pyrogen quantification and by measuring inflammatory responses in cell-based bioassays. The NUF completely retained oligodeoxynucleotides (ODN), whereas the RUF was fully permeable. Both filters tended to decrease biological activity of DNA in filtered bacterial lysates. The NUF reduced lipopolysaccharides (LPS) and LPS-induced biological activity by 100%, whereas the RUF produced filtrates with low but detectable levels of LPS in most cases. Peptidoglycans (PGN) were fully retained both by the NUF and the RUF. The new ultrafilter retained biologically active ODN, which has not yet been described for any other device used in dialysis, and it showed better or equal retention of LPS and PGN even with a smaller membrane surface and larger pore size.
authors.affiliation: Nephrology Division, University Hospital Gent, 9000 Gent, Belgium.
authors.forename: Griet
authors.initials: G
authors.lastname: Glorieux
authors.affiliation: Gambro Dialysatoren GmbH, Research &Development, 72379 Hechingen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Hulko
authors.affiliation: Gambro Dialysatoren GmbH, Research &Development, 72379 Hechingen, Germany.
authors.forename: Rose
authors.initials: R
authors.lastname: Speidel
authors.affiliation: Gambro Dialysatoren GmbH, Research &Development, 72379 Hechingen, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Brodbeck
authors.affiliation: Gambro Dialysatoren GmbH, Research &Development, 72379 Hechingen, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Krause
authors.affiliation: Nephrology Division, University Hospital Gent, 9000 Gent, Belgium.
authors.forename: Raymond
authors.initials: R
authors.lastname: Vanholder
mesh_terms: D000818:Animals; D004731:Endotoxins / Q000302:isolation & purification*; D015312:Hemodialysis Solutions; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008070:Lipopolysaccharides / Q000302:isolation & purification*; D008567:Membranes, Artificial; D051379:Mice; D041681:NIH 3T3 Cells; D011749:Pyrogens / Q000302:isolation & purification*; D006435:Renal Dialysis / Q000295:instrumentation*; D014462:Ultrafiltration / Q000379:methods*
chemical_list: D004731:Endotoxins; D015312:Hemodialysis Solutions; D008070:Lipopolysaccharides; D008567:Membranes, Artificial; D011749:Pyrogens