Effect of Dialyser Composition and Reuse on Neutrophil Count and Elastase α-1 Proteinase Inhibitor Complex Formation

Abstract

To assess the inter-relationship of leucopenia and PMN elastase release we undertook a prospective crossover study of 6 patients dialysed with new and reused cuprophane, cellulose acetate and polysulfone membranes. Serial blood samples were analysed for PMN count, and elastase-α 1-proteinase inhibitor complex (Eα1PI) concentrations. After 15 min dialysis with new membranes median PMN counts fell by 72.2%, 25.3% and 22.1% with cuprophane, cellulose and polysulfone, respectively. With reuse the decreases were reduced to 6.4%, 8% and 13.6%. All membranes produced a gradual increase of Eα1PI. Median Eα1PI accumulation rates (ng ml−1min−1) with new membranes were 175, 169 and 187 for cuprophane, cellulose acetate and polysulfone, respectively. With reuse of cuphro-phane and cellulose acetate these rates fell to 99 and 109 (p<0.05 and p<0.05, respectively), however, with polysulfone it remained unchanged at 180 ng ml−1 min−1. This study highlights differences between two aspects of the neutrophil response to haemodialysis, and demonstrates that extrapolation from individual parameters to conclusions concerning biocompatibility may be inappropriate.