PLASMA C-REACTIVE PROTEIN IS LINKED TO BACKFILTRATION ASSOCIATED INTERLEUKIN-6 PRODUCTION

Bacterial contamination of dialysate may enhance cytokine production i n hemodialysis. The authors tested the hypothesis that C-reactive prot ein and interleukin-6 (IL-6) may be linked in a large group of patient s exposed to backfiltration of dialysate over a long period of observa tion. Plasmas stored in a recently published multicenter study were re evaluated. Plasma C-reactive protein and IL-6 concentrations in patien ts with chronic uremia undergoing hemodiafiltration, which is known to be associated with backfiltration (Group II, 12 patients), were compa red with those found in patients treated with a modified hemodiafiltra tion modality without backfiltration (Group I, 16 patients), and in pa tients shifted from one modality to the other (Group III, 27 patients) , and in 10 patients on hemodialysis (Group IV) in a 1 year multicente r study. Plasma C-reactive and IL-6 both increased significantly (p < 0.002), but slowly (after 8 months) in Group II compared with I, and d uring the 4 month period in hemodiafiltration with backfiltration in G roup III. Backfiltration of dialysate with a moderate to low degree of contamination may enhance synthesis of cytokine and C-reactive protei n in the long term. Thus, the relevance for dialytic strategies aiming at improving dialysate quality or at reducing backfiltration is highl ighted.