EFFECT OF DIALYZER COMPOSITION AND REUSE ON NEUTROPHIL COUNT AND ELASTASE ALPHA-1 PROTEINASE-INHIBITOR COMPLEX-FORMATION

To assess the inter-relationship of leucopenia and PMN elastase release undertook a prospective crossover study of 6 patients dialysed with new and reuse cuprophane, cellulose acetate and polysulfone membranes. Serial blood samples we analysed for PMN count, and elastase-alpha 1-proteinase inhibitor complex (E-alpha-1PI) concentrations. After 15 min dialysis with new membranes median PMN counts fell by 72.2%, 25.3% an 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 E-alpha-1PI. Median E-alpha-1PI accumulation rates (ng ml-1 min-1) with new membranes were 175, 169 an 187 for cuprophane, cellulose acetate and polysulfone, respectively. With reuse of cuprophane and cellulose acetate these rates fell to 99 and 109 (p < 0.05 and p < 0.05, respective 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.