Fractionated plasma separation and adsorption: current practice and future options

Abstract

Fractionated plasma separation and adsorption (FPSA) is a method of albumin dialysis that is integrated into an extracorporeal liver support device (Prometheus(®)). This concept allows the effective removal of both protein-bound and water-soluble substances without the need for external albumin. Several studies comparing the in vivo extraction capacities of FPSA and molecular adsorbent recirculating system (MARS) concluded that detoxification by FPSA seems to be more effective than by MARS. Overall, FPSA therapy has been shown to be safe. Over the last few years, the anticoagulation protocol for FPSA therapy was optimised by using regional anticoagulation with citrate to avoid clotting of system components. Recently, the results of a large randomised-controlled multicentre trial (HELIOS) have been presented. Survival after 1 and 3 months was evaluated in 145 patients with acute-on-chronic liver failure comparing FPSA therapy with standard medical treatment versus standard medical treatment alone. There was no statistically significant survival benefit for patients undergoing FPSA therapy. However, patients with hepatorenal syndrome type I or MELD score >30 showed a significant survival benefit under FPSA in a predefined subgroup analysis. Furthermore, there have been promising results with FPSA in the treatment of refractory cholestatic pruritus. Regarding acute liver failure, only few data are currently available.

Evaluation of Encapsulated Liver Cell Spheroids in a Fluidised-Bed Bioartificial Liver for Treatment of Ischaemic Acute Liver Failure in Pigs in a Translational Setting

“…Purely artificial liver support devices, for example, those based on albumin dialysis did not significantly improve survival in recent clinical trials [2], [3], likely reflecting the complex functional repertoire of the liver that only a device containing a biological component can provide.…”

A preliminary study for constructing a bioartificial liver device with induced pluripotent stem cell-derived hepatocytes

“…Improvement of jaundice, hepatic encephalopathy, systemic hemodynamic dysfunction and/or portal hypertension has been observed by these systems [1,2]. However, these outcomes are temporary, and randomized control trials have failed to show clear a benefit of such systems to the long-term survival of these patients [3-7]. In theory, an ideal artificial liver system could permanently replace liver functions, providing most or even all normal liver functions such as detoxification and synthesis [8,9].…”

The Artificial Liver, in vivo Tissue Engineering, and Organ Printing

“…In contrast to SPAD and MARS, an albumin-permeable polysulfone membrane is used to filter the patient's albumin fraction into the secondary circuit, where direct purification from albumin-bound toxins by different adsorbers takes place. Afterward, conventional high-flux dialysis is performed inside the primary circuit [4].…”

“…In the HELIOS trial, there was no statistically significant difference in the overall survival between the study groups. However, a significant survival benefit was observed with FPSA therapy in two predefined subgroups, namely patients with hepatorenal syndrome type I and those with a Model for End-stage Liver Disease (MELD) score of >30 [4].…”