Pegylated interferon-α2a kinetics during experimental haemodialysis:: impact of permeability and pore size of dialysers

Background: Therapeutics in end-stage renal disease (ESRD) patients undergoing haemodialysis (HD) has to consider potential drug clearance during the dialysis procedure. Pegylated interferon-alpha (PEG-IFN-alpha), a middle-size protein drug active against viral hepatitis, allows convenient once-weekly dosing due to prolonged plasma half-life. Aim: To investigate the impact of permeability and dialyser pore size on PEG-IFN-alpha blood levels during experimental HD. Methods: Polymethylmetacrylate (PMMA) membrane 1.6 m(2) dialysers with three different permeabilities/pore sizes were selected. Results: A 40 kDa PEG-IFN-alpha2a (PEGASYS) was not cleared (< 5%) through low-flux/small pore size (25 Angstrom;B3A) and high-flux/middle-large pore size (60 Angstrom;BKP) dialysers, and was partially (approximate to15%) through intermediate permeability/large pore size (100 Angstrom;BKF) dialysers. In contrast, unmodified 17 kDa IFN-alpha2a(Roferon-A) was removed (65%-95%) through BKP or BKF, but not B3A, PMMA dialysers. Moreover, 12 kDaPEG-IFN-alpha2b(PegIntron) was cleared (40%-80%) through PMMA dialysers with pore sizes greater than or equal to 60 Angstrom. When B3A or BKP were replaced every hour PEG-IFN-alpha2a plasma levels remained constant throughout three experimental-HD-sessions, but PEG-IFN-alpha2b was cleared partially every BKP replacement. Porosity differ among high-flux dialysers. Neither PEG-IFN-alpha2a nor PEG-IFN-alpha2b were removed after three HD sessions through (27/31/33 Angstrom) pore size polysulphone dialysers. Although PEG-IFN-alpha2a was not cleared through middle pore-size (43 Angstrom/AN69ST) polyacrylonitrile dialyser, PEG-IFN-alpha2b was partially removed. Conclusions: The pharmacokinetics of Peg-IFN-alpha may vary in a patient on dialysis.