Evaluation of Biocompatibility and Performances of 4 Dialyzers in Different Mode Treatments

Prospective multicenter randomized cross-over study Number of patients : 32 (8 patients per group) Obtain objectives data to advise each hemodialyzer according to dialysis treatment and patient profile. To evaluate the different hemodialyzers and judge their extraction performances in HD and post HDF. Evaluation of the biocompatibility of the hemodialyzers and the patients' inflammatory status.

Medical devices studied : * Leoceed 21HX, hemodialyzer, High permeability PS membrane 2,1 m² , made by Nx Stage in Germany * Polypure 22S, hemodialyzer, High permeability PS membrane 2,2 m² , made by Allmed in Germany * VIE 21A hemodialyzer, High permeability PS membrane 2,1 m² coated in vitamin E, made by Asahi Kasei Medical in Japan * Rexsys 27H, hemodialyzer , High permeability PES membrane 2,7 m² , made by Medica in Italia These hemodialyzers are EC marked and are used in their own indications. Schema Details of the cross-over plan : 8 patients will be treated successively with the 4 hemodialyzers. Patients will be treated with the dialyzer "test" for the two first sessions of the week. During the last dialysis session of each week, only their usual dialyzer will be used as wash-out. A randomization will define the order of use of the dialyzers in the 4 centers. This order will be identical in a center. Number of patients : 32 (8 patients per center (4 centers)) Duration : One week per dialyzer