Assessment of bilirubin clearance capacity of a newly developed ion-exchange adsorption column and its possible use as a supportive therapy in hepatorenal syndrome

Bilirubin Removal by Polymeric Adsorbents for Hyperbilirubinemia Therapy

Hyperbilirubinemia, presenting as jaundice, is a life-threatening critical illness in newborn babies and acute severe hepatic failure patients. Over the past few decades, extracorporeal hemoadsorption by adsorbent therapy has been widely applied in the treatment of hyperbilirubinemia. The capability of hemoadsorption depends on the adsorbents. Most of the clinically used bilirubin adsorbents are made up of styrene/divinylbenzene copolymer and quaternary ammonium salt, which usually have poor biocompatibility and weak mechanical strength. To overcome the drawbacks of commercial polymer adsorbents, advanced synthetic and natural polymers with/without nanomaterials have been designed, and novel adsorbent fabrication technologies have also been developed. In this review, the adsorption mechanism of bilirubin adsorbents has been summarized, which is the basic criterion in adsorbent development. Furthermore, the preparation method, adsorption mechanism, relative merits and practicability of the emerging bilirubin adsorbents have been evaluated. Based on the existing studies, this work highlights the future direction of the efforts on how to design and develop bilirubin adsorbents with good overall clinical performance. Perhaps this study can change traditional perspectives and propose new strategies for bilirubin clearance from the aspects of pathogenic mechanisms, metabolic pathways, and material-based innovation.

Therapeutic Plasma Adsorption. A Review

Alternative techniques to the traditional plasma exchange are emerging in clinical practice for the treatment of different pathological conditions, particularly autoimmune diseases. Filtration is a technique used to separate blood cells from plasma, which may be further “treated” with other filters or columns. The case for cascade filtration and absorption onto a column is becoming stronger and stronger and the patient population is increasing. Alongside the “historical” techniques of adsorption onto a column, new systems (pairs of self-regenerating columns) and new products (columns with dextran sulphate, tryptophane, anti-human lipoprotein antibodies) are now available. Protein A in particular seems to open up new horizons; in therapeutic plasmapheresis, there are two versions, one Swedish and the other American, based on different theoretical premises and obtaining different results, with different biocompatibilities but good clinical results.

Biochemical Assessment and Clinical Evaluation of a Non-Ionic Adsorbent Resin in Patients with Intractable Jaundice

We investigated in vitro and in vivo the ability of a non-ionic adsorbing resin (styrenedivinylbenzene copolymer) to remove bilirubin and bile acids from human plasma. In preliminary experiments, human plasma from healthy donors, enriched in conjugated bile acids and bilirubin, and pooled plasma from jaundiced patients were recirculated through the resin column. The removal of bilirubin and bile acids was evaluated at two different flow rates (200 ml/min and 40 ml/min), and compared to an activated charcoal column. Four patients with severe jaundice were subsequently treated by 4-hour plasmaperfusion through the resin. The in vitro studies showed that after 1 hour the removal of bile acids was almost complete and bilirubin level decreased significantly, reaching a plateau after 4 hours. In the in vivo study, all treatments were well tolerated. After plasmaperfusion, serum bile acid levels decreased by 64.9–94.6% and total bilirubin by 35.3–57.7%. No clinical or biochemical side effects were observed. Our data suggest that plasmaperfusion through this resin is safe and efficient for removal of bilirubin and bile acids in jaundiced patients. Thus, it may serve as a method of artificial liver support in the treatment of cholestatic syndromes.

Bilirubin adsorption column Medisorba BL-300

Bilirubin adsorption column Medisorba BL-300 (Kuraray Medical Inc.) for the treatment of hyperbilirubinemia is introduced. The adsorbent packed in this column is the porous anion exchange resin coated with hydrophilic 2-hydroxyethyl methacrylate copolymer in order to improve blood compatibility. The adsorbent showed a high adsorption rate for direct bilirubin and indirect bilirubin in patient plasma in vitro. This column is used in plasmaperfusion therapy in clinical use. BL-300 showed high removal rate for direct bilirubin, indirect bilirubin and bile acid in clinical evaluation. BL-300 is approved in Japan and it has been used for the treatment of hyperbilirubinemia caused by many diseases such as liver failure and hepatitis.