THE EFFECT OF ULTRAFILTERED DIALYSATE ON THE CELLULAR CONTENT OF INTERLEUKIN-1 RECEPTOR ANTAGONIST IN PATIENTS ON CHRONIC-HEMODIALYSIS

We investigated the effect of dialysate ultrafiltration on the content of IL-1 receptor antagonist (IL-1Ra) in mononuclear cells (PBMC) as a marker of the inflammatory response. 11 patients on Cuprophan dialyze rs were randomly assigned to treatment with standard bicarbonate dialy sate first and then to ultrafiltered dialysate or the reverse order in a crossover design. In each treatment period (at least 4 weeks) weekl y separations of PBMC were performed before the start of dialysis. Cel lular content of IL-1Ra was determined in PBMC that were frozen immedi ately after separation; all values of IL-1Ra in each treatment period were averaged. The dialysate contained a median of 148 (range, 61-400) colony-forming units without dialysate filter; no bacterial growth wa s detected in ultrafiltered dialysate. The median endotoxin content wa s 80 pg/ml in nonfiltered dialysate; endotoxin was below 5 pg/ml in ah ultrafiltered dialysate samples. Cellular content of IL-1Ra decreased in all but 1 patient with the use of ultrafiltered dialysate (mean+/- SEM: 1,467+/-113 pg/ml without dialysate filter vs. 1,166+/-104 pg/ml with filter, p = 0.016). The present study demonstrates that the bacte rial contamination of the dialysate induces a systemic inflammatory re sponse in hemodialysis patients.