The solute removal characteristics and haemocompatibility of low-flux dialysers containing
Cuprophan,
cellulose acetate,
polymethylmethacrylate (
PMMA), and
polycarbonate-polyether (
Gambrane) membranes were compared in a multicentre cross-over clinical trial. While all four dialysers provided comparable removal of
urea and
creatinine, the dialyser containing
PMMA membrane showed a reduced ability to remove
phosphate compared to that containing
Cuprophan membrane. Significant
beta 2-microglobulin removal was obtained with the dialyser containing
Gambrane membrane, whereas the other three dialysers had no impact on plasma
beta 2-microglobulin concentrations. The ability to activate
complement, measured as changes in the plasma concentrations of
C3a des Arg and the
terminal complement complex, and to produce
leukopenia was greater for the dialyser containing
Cuprophan membrane than for the other three. The ability to activate
complement and cause
leukopenia was not consistent among the remaining three dialysers and the degree of
leukopenia could not be predicted from the level of complement activation. Neutrophil degranulation, as indicated by the release of
elastase-
alpha 1-proteinase inhibitor, occurred to a greater extent with the dialysers containing
Cuprophan and
Gambrane membranes. None of the dialysers was overtly thrombogenic as judged by changes in platelet count and plasma concentrations of the
thrombin-antithrombin III complex. Our results demonstrate that although there are many similarities between dialysers containing low-flux membranes, there are also significant differences. These differences may enable improvements in
therapy, while allowing continued use of low-flux dialysers.