On the mechanisms of haemodialysis-induced neutropenia: a study with five new and re-used membranes.

A prospective study was undertaken in 12 haemodialysed patients successively treated on five new as well as re-used dialyser membranes, that is cuprophane, cellulose acetate, polysulphone, polycarbonate, and polyacrylonitrile. A significant reduction of neutrophils occurred with every membrane during their first use, which improved only with cuprophane upon re-use. Thrombocytopenia was noted only when neutropenia reached very low values. Monocyte reduction occurred on cuprophane, cellulose acetate and polycarbonate, but did not improve during second use. C3d accumulation paralleled the time course of neutropenia only with cuprophane and cellulose acetate. Plasma collected at the extreme of neutropenia induced aggregation of control and predialysis cells, but did not aggregate autologous dialysed neutrophils collected at 5 min. Our data indicate that the mechanism linking complement activation to neutropenia is probably triggered by more than one factor.