Plasma exchange, a promising liver support system with still relevant uncertainties

Abstract

Hepatic failure develops in 3 clinical conditions: acute hepatitis, acute-on-chronic liver failure (ACLF), and after extended liver surgery. Jaundice and coagulopathy often occur in the setting of an intense systemic inflammatory response triggered by damage-associated molecular patterns and pathogen-associated molecular patterns, respectively, leading to the development of HE; immune dysfunction; and circulatory, renal, and respiratory failure. [1] The mortality rate is substantial in the absence of salvage liver transplantation (LT). Transplantation is currently the only treatment that improves survival in liver failure. However, the scarcity of organs for LT translates into an urgent need to develop effective liver support systems that act as a "bridge" to LT or recovery of the native liver. [2][3][4] An ideal liver support system should have detoxification, synthesis, and regulation functions (acid-base balance, electrolytes, etc.). It should be easy to use, safe, and cost-effective. [5] Different liver support therapies have been investigated. Methods can be divided into nonbiological and biological (with hepatocytes in the bioreactors) artificial devices. Fractionated Plasma Separation and Adsorption System/Prometheus and Molecular Adsorbent Recirculating System are albumin dialysis systems that rely on the scavenger capacity of albumin. These systems remove water-soluble and albumin-bound substances involved in the perpetuation of liver failure. Examples of biological systems are bioartificial liver and extracorporeal liver assist devices. [5] Artificial and bioartificial systems are complex to use, expensive, and importantly, have not been demonstrated to improve survival in acute liver failure (ALF) or ACLF. Current guidelines do not recommend their use in patients with liver failure. [2][3][4] More effective and simpler systems are therefore urgently needed.Plasma exchange (PE) is an extracorporeal therapy used in the treatment of several immune disorders. Until recently, the only indication for PE in patients with liver diseases was fulminant Wilson disease. [6] PE removes plasma by replacing it with fresh frozen plasma and/or albumin.