Arresting Dialysis-Related Amyloidosis: A Prospective Multicenter Controlled Trial of Direct Hemoperfusion with a beta2-Microglobulin Adsorption Column

Mass spectrometry-based proteomic analysis of proteins adsorbed by hexadecyl-immobilized cellulose bead column for the treatment of dialysis-related amyloidosis

BACKGROUND

Dialysis-related amyloidosis (DRA) is a severe complication in end-stage kidney disease (ESKD) patients undergoing long-term dialysis treatment, characterized by the deposition of β2-microglobulin-related amyloids (Aβ2M amyloid). To inhibit DRA progression, hexadecyl-immobilized cellulose bead (HICB) columns are employed to adsorb circulating β2-microglobulin (β2M). However, it is possible that the HICB also adsorbs other molecules involved in amyloidogenesis.

METHODS

We enrolled 14 ESKD patients using HICB columns for DRA treatment; proteins were extracted from HICBs following treatment and identified using liquid chromatography-linked mass spectrometry. We measured the removal rate of these proteins and examined the effect of those molecules on Aβ2M amyloid fibril formation in vitro.

RESULTS

We identified 200 proteins adsorbed by HICBs. Of these, 21 were also detected in the amyloid deposits in the carpal tunnels of patients with DRA. After passing through the HICB column and hemodialyzer, the serum levels of proteins such as β2M, lysozyme, angiogenin, complement factor D and matrix Gla protein were reduced. These proteins acted in the Aβ2M amyloid fibril formation.

CONCLUSIONS

HICBs adsorbed diverse proteins in ESKD patients with DRA, including those detected in amyloid lesions. Direct hemoperfusion utilizing HICBs may play a role in acting Aβ2M amyloidogenesis by reducing the amyloid-related proteins.

Beta-2 Microglobulin Amyloidosis: Past, Present, and Future

Almost half a century has elapsed since the first description of dialysis-related amyloidosis (DRA), a disorder caused by excessive accumulation of β-2 microglobulin (B2M). Within that period, substantial advances in RRT occurred. These improvements have led to a decrease in the incidence of DRA. In many countries, DRA is considered a "disappearing act" or complication. Although the prevalence of patients living with RRT increases, not all will have access to kidney transplantation. Consequently, the number of patients requiring interventions for treatment of DRA is postulated to increase. This postulate has been borne out in Japan, where the number of patients with ESKD requiring surgery for carpal tunnel continues to increase. Clinicians treating patients with ESKD have treatment options to improve B2M clearance; however, there is a need to identify ways to translate improved B2M clearance into improved quality of life for patients undergoing long-term dialysis.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

Molecular mechanisms underlying uremic toxin-related systemic disorders in chronic kidney disease: focused on β2-microglobulin-related amyloidosis and indoxyl sulfate-induced atherosclerosis-Oshima Award Address 2016

Uremic toxins are linked to chronic kidney disease (CKD)-related systemic diseases. β₂-Microglobulin (β₂-m), a water-soluble, middle-sized molecule, is associated with mortality and dialysis-related amyloidosis (DRA). DRA occurs in long-term dialysis patients, with β₂-m amyloid deposited mainly in osteoarticular tissues. We investigated a model of β₂-m amyloid fibril extension at neutral pH in the presence of trifluoroethanol or sodium dodecyl sulfate. Using this model, some biological molecules, including glycosaminoglycans and lysophospholipids, were found to be chaperones for β₂-m amyloid fibril extension. Several protein-bound solutes, such as indoxyl sulfate (IS) and p-cresyl sulfate, are independent risk factors for cardiovascular disease in CKD patients, especially those undergoing dialysis. We investigated kidney injury-induced acceleration of atherosclerosis in association with macrophage phenotypic change to a proinflammatory state as well as increased IS deposition in lesions in an animal model. IS directly induced macrophage inflammation and impaired cholesterol efflux to high-density lipoprotein (HDL) in vitro. In addition, a clinical study showed that HDL isolated from CKD patients induced proinflammatory reactions and impaired cholesterol efflux to macrophages. These findings suggest that protein-bound solutes, including IS, will induce dysfunction of both macrophages and HDL in atherosclerotic lesions. To remove uremic toxins efficiently, we demonstrated the potential efficacy of oral charcoal adsorbent and hexadecyl-immobilized cellulose beads in hemodialysis patients. These findings suggest that uremic toxins induce various CKD-related systemic disorders, and further therapeutic strategies will be needed to reduce uremic toxins enough and improve life expectancy in CKD patients.

Using Covalent Labeling and Mass Spectrometry To Study Protein Binding Sites of Amyloid Inhibiting Molecules

Amyloid aggregates are associated with several debilitating diseases, and there are numerous efforts to develop small molecule treatments against these diseases. One challenge associated with these efforts is determining protein binding site information for potential therapeutics because amyloid-forming proteins rapidly form oligomers and aggregates, making traditional protein structural analysis techniques challenging. Using β-2-microglobulin (β2m) as a model amyloid-forming protein along with two recently identified small molecule amyloid inhibitors (i.e., rifamycin SV and doxycycline), we demonstrate that covalent labeling and mass spectrometry (MS) can be used to map small-molecule binding sites for a rapidly aggregating protein. Specifically, three different covalent labeling reagents, namely diethylpyrocarbonate, 2,3-butanedione, and the reagent pair EDC/GEE, are used together to pinpoint the binding sites of rifamycin SV, doxycycline, and another molecule, suramin, which binds but does not inhibit Cu(II)-induced β2m amyloid formation. The labeling results reveal binding sites that are consistent with the known effects of these molecules on β2m amyloid formation and are in general agreement with molecular docking results. We expect that this combined covalent labeling approach will be applicable to other protein/small molecule systems that are difficult to study by traditional means.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.

Pharmacokinetic analysis of antibiotic adsorption (vancomycin and teicoplanin) by the Lixelle extracorporeal unit

PURPOSE

The pharmacokinetic properties of vancomycin (VAN) and teicoplanin (TEC) may be affected by adsorption during hemofiltration as well as hemoperfusion therapies. The aim of this in vitro study was to investigate VAN and TEC removal adsorption kinetics with mass balance analysis by direct hemoperfusion (DHP) with the Lixelle S-35 cartridge (Lixelle, Kaneka Corporation, Tokyo).

METHODS

Mock DHP was performed for 120 min using VAN and TEC solutions (46.08 ± 0.81 and 74.79 ± 1.24 mg/l per N = 6). Clinical plasma antibiotic concentrations were circulated in a closed circuit simulating DHP using an adsorption column (Lixelle S-35) at flow rate of 250 ml/min. Samples were collected at 10, 60, and 120 min through both arterial and venous ports; drug levels were measured with particle enhanced turbidimetric inhibition immunoassay and fluorescence polarization immunoassay. All tests were performed in triplicate.

RESULTS

Results subsequent to DHP at the primary assessment interval for VAN mass was 49.06 ± 1.47 mg, indicating a significant reduction of the starting mass (94.74 ± 1.63 mg). The observed reduction of TEC levels greatly exceeded that of VAN at the first interval (10 min). At 120 min of DHP, the estimated mass adsorption of VAN was 45.68 ± 2.26 mg, while the mesured total TEC mass adsorbed was 126.86 ± 0.91 mg.

CONCLUSIONS

A VAN adsorption plateau indicating the VAN loading dose may be required in patients receiving DHP with the Lixelle S-35. The total TEC mass was adsorbed subsequent to 60 min of circulation, so the loading dose should be closely considered. In addition, the Lixelle S-35 may represent an option as a rescue therapy in accidental overdose of TEC.

Fever associated with severe dialysis-related amyloidosis

Dialysis-related amyloidosis (DRA) is one of the most important complications in patients on long-term hemodialysis (HD). DRA often affects the osteoarticular system; however, little is known about the role of β₂-microglobulin in the induction of fever in HD patients. We report a 64-year-old woman on long-term (24 years) HD who developed polyarthralgia and intermittent fever. Infectious diseases, connective tissue diseases, and malignant neoplasm were ruled out. Computed tomography and magnetic resonance imaging showed swelling of the soft tissues around bilateral shoulder and hip joints, suggestive of amyloid deposits. Gallium scintigraphy showed abnormal uptake in the vicinity of several large joints. It was presumed that the fever was related to the amyloid joint deposits, and the patient was treated with prednisolone and β₂-microglobulin adsorption therapy. The treatment resulted in the resolution of fever, relief of arthralgia, and normalization of several inflammatory cytokines and C-reactive protein. The findings suggest that massive DRA could cause systemic inflammatory response in patients on long-term HD.

The blood compatibilities of blood purification membranes and other materials developed in Japan

The biocompatibilities in blood purification therapy are defined as "a concept to stipulate safety of blood purification therapy by an index based on interaction in the body arising from blood purification therapy itself." The biocompatibilities are associated with not only materials to be used but also many factors such as sterilization method and eluted substance. It is often evaluated based on impacts on cellular pathways and on humoral pathways. Since the biocompatibilities of blood purification therapy in particular hemodialysis are not just a prognostic factor for dialysis patients but a contributory factor for long-term complications, it should be considered with adequate attention. It is important that blood purification therapy should be performed by consistently evaluating not only risks associated with these biocompatibilities but also the other advantages obtained from treatments. In this paper, the biocompatibilities of membrane and adsorption material based on Japanese original which are used for blood purification therapy are described.

Long-term efficacy and safety of the small-sized β2-microglobulin adsorption column for dialysis-related amyloidosis

Dialysis-related amyloidosis (DRA) is one of the major complications often seen in long-term dialysis patients, and is one of the factors that decreases quality of life. β2-microglobulin (β2-m) is considered to be a major pathogenic factor in dialysis-related amyloidosis. The Lixelle adsorbent column, with various capacities, has been developed to adsorb β2-m from the circulating blood of patients with dialysis-related amyloidosis. Using a minimum type of β2-m-adsorbing column (Lixelle S-15), we evaluated its therapeutic efficacy and safety in dialysis patients. Seventeen hemodialysis patients with DRA were treated with the S-15 column for one year. Treatment was performed three times a week in this study. During the study period, pinch strength, visual analog scale for joint pain, and activities of daily living were evaluated every three months, and blood sampling was performed every six months. After one year's treatment with the S-15 column, the β2-m level decreased from 29.3±9.6mg/L to 24.7±5.1mg/L (P<0.05), and the high sensitive C-reactive protein level decreased from 2996±4380ng/mL to 1292±1774ng/mL. After one year of S-15 column use, pinch strength increased from 5.9±3.0pounds to 7.2±3.2pounds (P<0.05), and the visual analog scale for joint pain and activities of daily living score also improved. Long-term use of the Lixelle S-15 column is safe and effective for improvement of quality of life in chronic dialysis patients. Improvement of chronic inflammation may be one of the mechanisms through which the beneficial effects of the column is effected.

Atypical rapid progression of osteoarticular amyloidosis involving the hip in a patient on hemodialysis using polyacrylonitrile membranes

Amyloidosis related to dialysis is a well-known complication affecting many organ systems, in particular the musculoskeletal system. In 1985 Shirahama et al. (Biochem Biophys Res Commun 53:705-709, 1985) identified beta-2 microglobulin (MG) as the offending constituent by using protein purification techniques. Amyloidosis has been increasing in prevalence because of longer life spans and increased chronic medical conditions such as end-stage renal disease. When dialysis-related amyloidosis involves the musculoskeletal system, it affects the shoulder girdle, the so called shoulder pad sign, the wrist, hip, knee, and spine (Resnick, Diagnosis of bone and joint disorders, 4th edn., pp. 2054-2058 and 2176-2183, 2002). Other osteoarticular manifestations of amyloidosis include osteoporosis, lytic lesions, and pathologic fractures. It has been well documented that the prevalence of amyloid is dependent on duration of dialysis-over 90% in patients on dialysis for over 7 years (Jadoul, Nephrol Dial Transplant 13:61-64, 1998). However, a recent changeover to high-flux membranes used in hemofiltration has been reported to delay its onset (Campistol et al., Contrib Nephrol 125:76-85, 1999). We report on the radiographic, nuclear medicine, and computed tomography (CT) findings of osteoarticular amyloidosis involving the hip, and sequence its atypical rapid onset. The imaging, histopathological findings, and differential diagnosis are discussed.

Current clinical aspects of dialysis-related amyloidosis in chronic dialysis patients

The current understanding of dialysis-related amyloidosis has evolved over the past two decades. In the early 1980s, several researchers found amyloid deposits in the synovia of carpal tunnel syndrome (CTS), which have been recognized as a complication of chronic hemodialysis. The enigma was resolved in 1985, when beta2-microglobulin (beta2-m) with a molecular weight of 12,000 Da was identified as the major constitutional protein of this amyloid. Amyloid fibrils of this type that contain the sub-unit protein of human leukocyte antigens (HLA), beta2-m, deposit predominantly in osteoarticular tissues, inducing musculoskeletal symptoms such as CTS, polyarthralgia, bone cyst showing radiolucency at X-ray examination and destructive spondyloarthropathy. In addition, extra articular symptoms such as ischemic colitis, megaloglossia, and heart failure, that is, systemic involvement occasionally occur. We confirmed that the prevalence of CTS increases with duration of dialysis. Most patients with CTS associated with beta2-m amyloid deposits have undergone hemodialysis for 10 years or more. Up to 50% of patients had developed this complication after 20 years and the percentage was even higher after 25 years. General categories of therapeutic approaches for amyloidosis include prevention of onset or progression, symptomatic therapy (conservative treatment, orthopedic procedures, and physiotherapy), and renal transplantation. It is critical to elucidate the detail mechanisms of the amyloid fibril formation, and establish its radical treatment. It is also important to develop novel therapies such as cell implantation to compensate for normal kidney functions of uremic toxin protein metabolism.

Adsorption of the uremic toxin p-cresol onto hemodialysis membranes and microporous adsorbent zeolite silicalite

Para-cresol CH3C6H4OH is a protein-bound solute which is not eliminated efficiently by hemodialysis systems. In this study, we present adsorption of p-cresol as a complementary process to hemodialysis. The kinetics and isotherms of adsorption onto cellulose-based membranes (cellulose diacetate and triacetate), synthetic membranes (polyamide, polysulfone, polyacrylonitrile and polymethylmethacrylate) and microporous zeolite silicalite (MFI), have been evaluated in static conditions. The results indicate that p-cresol has a low affinity to all membranes but polysulfone and polyamide and that the times to reach equilibrium conditions are slow. In contrast, equilibration time on silicalite is fast (2 min to eliminate 90%) while adsorption levels are high (maximum adsorption about 106 mg g(-1)). Adsorption onto microporous adsorbents could be a novel way to eliminate uremic toxins from blood.

A Serial Copolymerization Procedure for Manufacturing Immunoadsorption Walls as a Potential Unit in Conjunction With Hemodialysis Filters

A functional immunoadsorption wall for removal of beta-2-microglobulin has been made by partially incomplete two-stage copolymerization of acrylamide with immunoadsorbent. However, a substantial amount of immunoadsorbent needs to be flushed away after the copolymerization process. Thus, to enhance the utilization efficiency of immunoadsorbent, the flushed-away immunoadsorbent was further recovered, and the copolymerization was conducted in series to produce three consecutive immunoadsorption walls in this study. Preliminary removal tests show that similar removal patterns were obtained for these immunoadsorption walls. Although it is not timely to conclude that a clinically applicable immunoadsorption wall has taken shape, the development of a partially incomplete two-stage polymerization method and its associated techniques indeed provide a good basis for large-scale manufacturing immunoadsorption walls.

Therapeutic Apheresis-State of the Art in the Year 2005

Therapeutic apheresis is an extracorporeal blood purification method for the treatment of diseases in which pathological proteins or cells have to be eliminated. Selective plasma processing is more efficient in pathogen removal than unselective plasma exchange and does not require a substitution fluid like albumin. This overview presents the various selective devices for the treatment of plasma (plasmapheresis) and blood cells (leukocyte apheresis). Prospective randomized trials were performed for the treatment of age-related macular degeneration (Rheopheresis), sudden hearing loss (heparin-induced lipoprotein precipitation [HELP]), rheumatoid arthritis (Prosorba), dilative cardiomyopathy (Ig-Therasorb, Immunosorba), acute-on-chronic liver failure (molecular adsorbent recirculating system [MARS]), and ulcerative colitis (Cellsorba). Prospective non-randomized controlled trials were carried out treating hypercholesterolemia (Liposorber) and crossmatch-positive recipients before kidney transplantation (Immunosorba). Uncontrolled studies were done for ABO-incompatibility in living donor kidney transplantation (KT) (Glycosorb), acute humoral rejection after KT (Immunosorba) and acute liver failure (Prometheus). According to the 2002 International Apheresis Registry covering 11428 sessions in 811 patients, 79% of the patients showed an improvement of their condition by apheresis and only a few sessions were fraught with adverse effects (AE). The major AE were blood access difficulties (3.1%) and hypotension (1.6%). In summary, therapeutic apheresis is a safe and effective procedure for the treatment of diseases refractory to drug therapy.

β2-Microglobulin-selective direct hemoperfusion column for the treatment of dialysis-related amyloidosis

Lixelle is a direct hemoperfusion-type adsorption column that was developed to selectively eliminate beta2-microglobulin (beta2-m) from the circulating blood of patients with dialysis-related amyloidosis (DRA). The adsorbent in Lixelle comprises porous cellulose beads to which hydrophobic hexadecyl alkyl chain is covalently bound. One milliliter of wet Lixelle beads eliminates more than 1 mg of beta2-m in vitro. In hemodialysis patients who were treated with Lixelle, Lixelle improved joint pain, nocturnal awakening, pinch strength, motor terminal latency, and their activity of daily living. The adsorbent adsorbs beta2-m selectively but not specifically, as well as inflammatory cytokines such as interleukin-1beta and IL-6 which are considered to be involved in the development of DRA. Lixelle treatments reduce the circulating levels of beta2-m and inflammatory cytokines, thereby improving the symptoms of patients with DRA.

From chance to frequent encounters: Origins of β2-microglobulin fibrillogenesis

It is generally accepted that amyloid formation requires partial, but not complete unfolding of a polypeptide chain. Amyloid formation by beta-2 microglobulin (beta2m), however, readily occurs under strongly native conditions provided that there is exposure to specific transition metal cations. In this review, we discuss transition metal catalyzed conformational changes in several amyloidogenic systems including prion protein, Alzheimer's and Parkinson's diseases. For some systems, including beta2m from dialysis related amyloidosis (DRA), catalysis overcomes an entropic barrier to protein aggregation. Recent data suggest that beta2m samples conformations that are under thermodynamic control, resulting in local or partial unfolding under native conditions. Furthermore, exposure to transition metal cations stabilizes these partially unfolded states and promotes the formation of small oligomers, whose structures are simultaneously near-native and amyloid-like. By serving as a tether, Cu(2+) enables the encounter of amyloidogenic conformations to occur on time scales which are significantly more rapid than would occur between freely diffusing monomeric protein. Once amyloid formation occurs, the requirement for Cu(2+) is lost. We assert that beta2m amyloid fiber formation at neutral pH may be facilitated by rearrangements catalyzed by the transient and pair wise tethering of beta2m at the blood/dialysate interface present during therapeutic hemodialysis.

Historical background and clinical treatment of dialysis-related amyloidosis

Dialysis-related amyloidosis (DRA) is a frequent and serious complication in patients on long-term dialysis. The amyloid has a marked affinity for joint tissues, and carpal tunnel syndrome, polyarthralgia, destructive spondyloarthropathy, and bone cysts are the major clinical manifestations of DRA. beta(2)-Microglobulin (beta(2)-m) was identified as the major protein constituent of the amyloid fibrils. Risk factors for the development of DRA include age, duration of dialysis treatment, use of low-flux dialysis membrane, use of low purity dialysate, monocyte chemoattractant protein-1 GG genotype, and apolipoprotein E4 allele, although the retention of beta(2)-m in the plasma appears to be prerequisite. Clinical therapeutic strategies for DRA include dialysis, medical or surgical therapy, and renal transplantation. Preventive measures have attempted to remove beta(2)-m from the serum by using high-flux membranes and a beta(2)-m adsorption column in hemodialysis. Renal transplantation is a radical approach to treating the arthralgias attributed to the amyloid deposits while the regression of dialysi-related amyloid deposits is not identified after successful renal transplantation in many studies. It is necessary to elucidate the pathogenesis of DRA and to establish more effective prevention and therapy in the future.