Long-term influence of dialysis treatment on beta 2-microglobulin, interleukin-2 R and tumour necrosis factor.

: Recently much interest has been focused on the phenomena produced by the interaction between blood and dialytic membranes. The aim of this study was to evaluate beta 2-M, Il-2 and TNF changes in relation to the long-term use of different membranes (CU, PAN-AN69, PMMA, PS) and different dialytic treatments (HD, HDF, AFB). Plasma beta 2-M was significantly increased in patients dialysed with CU compared to synthetic membranes, and decreased in AFB compared to HD and HDF. Intradialytic changes of beta 2-M, corrected for haemoconcentration, resulted in a significant increase with CU and PMMA, while a decrease was found with PAN-AN69 and PS and during convective treatments, more evident during haemofiltration performed with sterile dialysate without acetate. I1-2R was increased in all patients compared to normal subjects, without any intradialytic change, regardless of the type of membrane used. TNF was in the normal range. The different decrease of beta 2-M observed with synthetic membranes, the stable intradialysis I1-2 R values during HD performed with membranes non-permeable to endotoxins and during AFB, and the absence of detectable TNF support the hypothesis that dialysate plays an important role in activating beta 2-M and cytokines, together with other factors.