Acute-on-chronic liver failure (ACLF) is accompanied by marked
intrahepatic cholestasis leading to accumulation of cytotoxic
bile acids. Extracorporeal liver support systems efficiently remove
bile acids, but their effect on
bile acid composition in ACLF is unknown. The aim of the present study was to compare elimination of individual plasma
bile acids by
albumin dialysis (Molecular Adsorbents Recirculating System, MARS) and fractionated plasma separation (Prometheus). Eight consecutive patients with ACLF underwent alternating 6-hour sessions with MARS or Prometheus in a randomized, cross-over design. Serum samples were obtained before, during, and after each treatment, and individual
bile acids including
cholic acid and
chenodeoxycholic acid (CDCA) were measured by gas chromatography. MARS and Prometheus removed total
bile acids to a similar extent (reduction ratio, 45% and 46%, respectively). Both devices cleared
cholic acid more efficiently than did CDCA. The molar fraction of CDCA (fCDCA) was elevated at baseline and correlated with the degree of
liver dysfunction. Prometheus but not MARS treatments further increased fCDCA. Although both devices eliminate total
bile acids to a similar extent, clearance of individual
bile acids is different, leading to a slight change of the
bile acid profile toward hydrophobic
bile acids during Prometheus treatments.