Gene expression of interleukin-1β during hemodialysis

Gene expression of interleukin-1β during hemodialysis. It is still controversial whether the hemodialysis (HD) procedure is an inflammatory process in vivo. Therefore, we studied the gene expression of interleukin-1β (IL-1β) as a marker of inflammation in peripheral blood mononuclear cells (PBMC) of patients during HD by Northern blotting and polymerase chain reaction. Compared to PBMC separated pre-HD (1.0 densitometric units), the amount of IL-1β mRNA was increased in PBMC leaving the dialyzer (12.2 ± 2 densitometric units, P < 0.01), but was not increased in PBMC re-entering the dialyzer from the systemic circulation (0.6 ± 0.1 densitometric units) in all 12 patients studied. The maximal amount of IL-1β mRNA in PBMC was seen at five minutes after start of HD. There was a significant correlation between the increase in IL-1β mRNA and the increase in activated complement C5a (r = 0.71, P < 0.01). HD using less complement-activating membranes (hemophan, polysulfone, polyamide or polyacrylonitrile) resulted in no detectable IL-1β mRNA. Furthermore, a monoclonal antibody against human C5a reduced the increase in IL-1β mRNA by 83% (P < 0.05), indicating that C5a plays a major role for induction of IL-1β mRNA during HD. This study demonstrates that during HD with regenerated cellulose, gene expression for IL-1β takes place in PBMC.