Sorbents in acute renal failure and end-stage renal disease: middle molecule and cytokine removal.

Renal replacement therapy in acute renal failure (ARF) and chronic renal failure (end-stage renal disease; ESRD) has been based on the use of modifications of dialysis (continuous arteriovenous hemofiltration and hemodiafiltration) to remove middle-molecular-weight toxins, consisting of low-molecular-weight proteins and peptides (LMWP) and cytokines involved in inflammation. High-flux dialyzers are not efficient at removing LMWP, and for this reason, sorbents have been studied to augment or replace dialysis. Removal of LMWP such as beta2-microglobulin, leptin, complement factor D, angiogenin and cytokines such as interleukin (IL)-1, IL-6, IL-10, IL-18 and tumor necrosis factor-alpha has been established in animal models of sepsis and in ESRD patients using sorbents.