Haemodialysis-induced leucopenia and activation of complement: effects of different membranes

The effects on neutrophil count and complement activity of five different haemodialysis membranes were studied. There was no correlation between the degree of neutropenia and intensity of complement activation. With cuprophan membrane both occurred simultaneously but to unrelated degrees; polyacronitrile induced mild, not significant neutropenia but marked activation of complement; polycarbonate membranes induced severe neutropenia without detectable complement activation. Where complement activation occurred it was via the alternative pathway. Haemodialysis induced neutropenia may have many causes and complement activation is probably not the major responsible factor.