Clinical testing of a new, low-flux polysulfone membrane. Results of a 26-week study.

In a 6-month study, a new hollow-fiber (HF) dialyzer with a modified polysulfone (PS) membrane was evaluated in 12 hemodialysis patients. Seven of them had previously used a cuprophane (CU) HF and five a polymethylmethacrylate (PMMA) HF dialyzer. The PS dialyzer reduced the concentration of serum creatinine by 54 +/- 5% (SD), that of urea by 59 +/- 5%, that of urate by 62 +/- 6% and that of phosphate by 40 +/- 12%; the mean urea index (Kt/V) was 0.9. Heparin consumption diminished with the PS dialyzer compared with the PMMA dialyzer. The serum predialysis beta-2-microglobulin (beta 2M) concentrations rose by 5.4 mg/l (mean). The intradialytic beta 2M measurements showed insignificant changes in all the membranes studied. Eosinophilia was initially observed in 4/12 (33%) of the patients, all using an ethylene oxide (ETO)-sterilized CU dialyzer. At the end of the study this figure had decreased to 1/12 (8%). The serum IgE concentrations also decreased significantly. IgE class antibodies to ETO were initially detected in 2 patients. The level decreased clearly in 1 of them after switching to the PS dialyzer. The new PS dialyzer was found to be effective, possibly less allergenic and, owing to its moderate hydraulic permeability, suitable for routine dialyses.