Effect of extracorporeal liver support by molecular adsorbents recirculating system and Prometheus on redox state of albumin in acute-on-chronic liver failure.

Oxidative stress is believed to play an important role in acute-on-chronic liver failure (AoCLF). Albumin, an important transport vehicle, was found to be severely oxidized in AoCLF patients. Extracorporeal liver support systems may exert beneficial effects in AoCLF via removal of albumin-bound toxins. At present, two systems are commercially available, the molecular adsorbents recirculating system (MARS) and fractionated plasma separation, adsorption and dialysis (FPAD, also known as Prometheus). The aim of this study was to compare the effect of MARS and Prometheus treatments on the redox state of human serum albumin. Eight patients with AoCLF underwent alternating treatments with either MARS or Prometheus in a randomized cross-over design. Sixteen treatments (eight MARS and eight Prometheus) were available for analysis. The fraction of human mercaptalbumin (HMA), human nonmercaptalbumin-1 (HNA1), and human nonmercaptalbumin-2 (HNA2) were measured before and after single MARS and Prometheus treatments and during follow-up. In AoCLF patients the oxidized fractions of albumin, HNA1, and HNA2 were markedly increased. Both MARS and Prometheus treatments resulted in a shift of HNA1 to HMA, while HNA2 was not significantly affected. This shift in albumin fractions was transient and disappeared within 24 h after treatment. There were no significant differences between MARS and Prometheus treatments with respect to the redox state of albumin. Both MARS and Prometheus treatments lead to transient improvements of the redox state of albumin, which could be beneficial in the treatment of AoCLF.