Impact of dialyzer membrane selection on cellular responses in acute renalfailure: A crossover study

Background. When acute renal failure (ARF) is severe enough to require dial ysis, in-hospital mortality rates approach 60%. These alarming figures have been ascribed in part to advanced age and the high prevalence of comorbid conditions. In the past several years, a number of attempts have been made to investigate the impact of dialyzer membrane type on clinical outcomes. U nfortunately, to date, clinical studies addressing this question have repor ted conflicting results. Methods. This crossover study examined the effect of dialyzer membrane type on cytokine synthesis by peripheral blood mononuclear cells (PBMCs), super oxide release by neutrophils. and apoptosis or programmed cell death of neu trophils in 24 patients with ARF requiring intermittent hemodialysis. The p atients were assigned in an alternate order to a low-flux cellulose acetate (CA) or polysulfone (PS) dialyzer. After three consecutive dialysis sessio ns, patients were crossed over to the second dialyzer for three additional treatments. These cellular responses were measured upon dialyzer assignment and at the third and sixth dialysis session in relationship to the dialyze r type. Results. The results of the study showed no impact of dialyzer biocompatibi lity on synthesis of tumor necrosis factor-a (TNF-a) or interleukin 10 (IL- 10) by PBMCs, superoxide release by neutrophils, or neutrophil apoptosis. T his held true regardless of the initial dialyzer assignment. Furthermore, t here was no correlation between dialysis adequacy (measured by single-pool Kt/V) and postdialysis cellular responses. Conclusions. In summary, this study refines the question of biocompatibilit y by comparing a substituted cellulose rather than unsubstituted cellulose dialyzer to a PS dialyzer in the setting of ARF. The results failed to demo nstrate a dialyzer advantage on the selected cellular responses.