Effects of membrane characteristics on cytokine production by mononuclear cells in regular haemodialysis patients

Abstract

To determine the relationship between haemodialysis and cytokine production, the effects of solute permeability and biocompatibility of dialysis membranes on cytokine production by mononuclear cells were evaluated. Eighteen stable haemodialysis patients were divided into three groups and underwent haemodialysis under the same conditions except for the dialysis membrane used. Endotoxin in dialysate remained at concentrations of 10 pg/ml or less throughout the study. Haemodialysis was performed for a total of 6 weeks. Group A used a regenerated cellulose low-flux membrane during the first 2 weeks, a regenerated cellulose high-flux membrane during the next 2 weeks and a polymethylmethacrylate (PMMA) high-flux membrane during the last 2-week period, while Group B used the regenerated low-flux cellulose membrane first, followed by the PMMA low-flux membrane and PMMA high-flux membrane. Group C used the same membrane throughout the 6-week study period. Peripheral mononuclear cells were sampled before, 30 min after the start and upon completion of the final dialysis session and incubated for 18 h in the presence and absence of lipopolysaccharide (LPS) stimulation. Tumour necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta) and IL-6 concentrations in the supernatant and cell lysate were determined. In all groups, cytokine production just before the final dialysis using each membrane was comparable regardless of the presence or absence of LPS stimulation. LPS-stimulated TNF-alpha production decreased significantly 30 min after the start of dialysis compared to the predialysis baseline. This change was not affected by the type of membrane used.(ABSTRACT TRUNCATED AT 250 WORDS)