We studied 22 children on chronic HD for at least 3 months and then switched them to HDF, standardizing all other dialysis related parameters and dialysis time, in order to determine the intra-individual changes in markers of oxidative stress (nitrotyrosine, AGEs, oxidized low density lipoprotein [ox-LDL], total antioxidant capacity [TAC]), inflammation (ß2M, IL-6, IL-10, high sensitive C-reactive protein [hsCRP]), and endothelial dysfunction (ADMA, symmetric dimethyl arginine [SDMA]), on different dialysis modalities. Here, IL6 is linked to endothelial dysfunction.