Immunoadsorption patients with multiple sclerosis: an open-label pilot study

Immunoadsorption as a method of antibody donation during the COVID-19 pandemic

BACKGROUND AND OBJECTIVES

Initial therapeutic efforts to treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) included the use of plasma from convalescent donors containing anti-SARS-CoV-2 antibodies. High-neutralizing antibody titres are required for therapeutic efficacy. This study aims to show that immunoadsorption followed by tangential flow filtration can be used to obtain antibody concentrates with high-neutralizing capacities.

MATERIALS AND METHODS

Eligible donors (n = 10, five males and three females) underwent immunoadsorption using adsorber columns specific for human antibodies. Glycine-washed out eluates of 1.5 L volume were further concentrated by tangential flow filtration using 30 kDa ultrafiltration membranes. The same membranes were applied for diafiltrations to exchange residual glycine for 0.9% normal saline.

RESULTS

Antibody concentrates were obtained within 8 h from the start of donation and had 4.58 ± 1.95, 3.28 ± 1.28 and 2.02 ± 0.92 times higher total IgG, IgA and IgM concentrations, 3.29 ± 1.62 and 3.74 ± 0.6 times higher SARS-CoV-2 N and S antibody concentrations and 3.85 ± 1.71 times higher SARS-CoV-2 S-specific IgG concentrations compared to the donors' peripheral blood. The specific SARS-CoV-2 virus neutralization capacities increased in all but one concentrate. All antibody concentrates (50-70 mL final volume) passed microbiological tests, were free of hazardous glycine levels and could be stored at -80°C and 4°C for 1 year with 20 ± 3% antibody loss.

CONCLUSION

Immunoadsorption followed by tangential flow filtration is a feasible procedure to collect IgG, IgA and IgM as well as SARS-CoV-2 N- and S-specific antibody concentrates of low volume, free of albumin and coagulation factors. Whether these concentrates can be used as passive immunisation in infected patients remains to be elucidated.

Immunadsorption zur Herstellung von COVID-19 Antikörperkonzentraten

Seit mehr als 2 Jahren hält die COVID-19 Pandemie die ganze Welt in Atem. Vor Einführung der Impfung schien die Anwendung von Frischplasmen rekonvaleszenter Spender nach Einzelfallberichten ein vielversprechender Therapieansatz, insbesondere, wenn sie bereits in der Frühphase der Erkrankung eingesetzt werden. In multizentrischen Studien großer Fallzahlen blieben die Ergebnisse unter den Erwartungen, weshalb in Deutschland keine eindeutige Leitlinienempfehlung zur Anwendung von rekonvaleszenten Plasmen (RKP) existiert.

Ein Grund dafür könnten schwankende und zu Beginn der RKP-Anwendung zu niedrige Konzentrationen an COVID-19 Antikörpern in der überwiegenden Zahl der Plasmaeinheiten sein – was wiederum das Ausbleiben einer überzeugenden klinischen Wirksamkeit erklären könnte.

Daher verfolgen wir eine Strategie, die die selektive Sammlung und Konzentrierung menschlicher Immunglobuline aus einer Spende mittels Immunadsorption ermöglicht.

COVID-19 antibody donation using immunoadsorption: Report of two cases

For more than a year the whole world is suffering from the COVID-19 pandemic with no treatment option in sight. Administration of plasma from convalescent donors containing anti-SARS-CoV-2 antibodies, though promising according to case reports, failed to show a clear benefit in a greater number of trials. One reason could be varying and low antibody contents in a majority of plasma units hampering standardization and clinical efficacy. Besides, other plasma components unnecessarily transfused like coagulation factors might promote hypercoagulation seen in severe COVID-19 etiopathology. We therefore hypothesized that instead of collecting whole plasma units, convalescent donors could donate solely immunoglobulins by undergoing immunoadsorption, a mode of therapy regularly applied in autoimmune diseases. Here, we report the results of the first two antibody donations performed at the University Hospital Düsseldorf. In both cases, immunoadsorptions were very well tolerated with no side effects. Collected and neutralized eluates were concentrated using tangential flow filtration increasing the concentration of immunoglobulins 10fold as compared to peripheral blood and leading to probably eight times more neutralizing antibodies than in one plasma unit. Therefore, immunoadsorption can be used as a method of antibody donation. Whether these donated antibodies can be used as passive immunization in acutely infected patients remains to be elucidated.

Plasma Exchange or Immunoadsorption in Demyelinating Diseases: A Meta-Analysis

Multiple sclerosis (MS) is an inflammatory disease mainly affecting the central nervous system. In MS, abnormal immune mechanisms induce acute inflammation, demyelination, axonal loss, and the formation of central nervous system plaques. The long-term treatment involves options to modify the disease progression, whereas the treatment for the acute relapse has its focus in the administration of high-dose intravenous methylprednisolone (up to 1000 mg daily) over a period of three to five days as a first step. If symptoms of the acute relapse persist, it is defined as glucocorticosteroid-unresponsive, and immunomodulation by apheresis is recommended. However, several national and international guidelines have no uniform recommendations on using plasma exchange (PE) nor immunoadsorption (IA) in this case. A systematic review and meta-analysis was conducted, including observational studies or randomized controlled trials that investigated the effect of PE or IA on different courses of MS and neuromyelitis optica (NMO). One thousand, three hundred and eighty-three patients were included in the evaluation. Therapy response in relapsing-remitting MS and clinically isolated syndrome was 76.6% (95%CI 63.7–89.8%) in PE- and 80.6% (95%CI 69.3–91.8%) in IA-treated patients. Based on the recent literature, PE and IA may be considered as equal treatment possibilities in patients suffering from acute, glucocorticosteroid-unresponsive MS relapses.

Immunoadsorption or plasma exchange in steroid-refractory multiple sclerosis and neuromyelitis optica

BACKGROUND

Plasma exchange (PE) and immunoadsorption (IA) are alternative treatments of steroid-refractory relapses of multiple sclerosis (MS) or neuromyelitis optica (NMO).

METHODS

Adverse events and neurological follow-ups in 127 MS- (62 PE, 65 IA) and 13 NMO- (11 PE, 2 IA) patients were retrospectively analyzed. Response was defined by improvements in either expanded disability status scale (EDSS) by at least 1.0 or visual acuity (VA) to 0.5, confirmed after 3 and/or 6 months.

RESULTS

Hundred and forty patients were included in safety analysis, 102 patients provided sufficient neurological follow-up-data. There were no significant differences between IA and PE in side effects (3.9% vs 3.6%, P = .96) or response-rate (P = .65). Responders showed significant lower age (P = .02) and earlier apheresis-initiation (P = .01). Subgroup-analysis confirmed significant lower age in patients with relapsing-remitting MS (RRMS) /clinical isolated syndrome (CIS).

CONCLUSION

IA and PE seem equally safe and effective in steroid-resistant MS- or NMO-relapses. Early apheresis and low patient age are additional prognostic factors.

Immunoadsorption with regenerating systems in neurological disorders --A single center experience

In recent years, immunoadsorption is increasingly recognized as an alternative treatment approach replacing therapeutic plasma exchange in a variety of neurological disorders. While most experience is based on the application of single-use tryptophan adsorbers, less data exists on the application of more efficient regenerating adsorber columns. We here report the systematic use of a regenerating adsorber system in various neurological indications such as multiple sclerosis, encephalitis, myasthenia gravis and chronic inflammatory demyelinating polyneuropathy, providing the expected treatment success in regard to reduction of immunoglobulins and antibody clearance, together with a low rate of adverse events. As it has been shown for single-use columns before, immunoadsorption with regenerating adsorbers can be successfully applied in disorders without known specific antibodies such as multiple sclerosis. Regenerating systems offer the perspective to provide a more efficacious long term treatment perspective for such patients.

[Immunoadsorption for steroid-unresponsive multiple sclerosis-relapses: clinical data of 14 patients]

BACKGROUND

Multiple sclerosis (MS) is a chronic inflammatory demyelinating immune-mediated disease of the central nervous system, often associated with relapses. Plasma exchange (PE) has become established as an escalation therapy for steroid-unresponsive relapses in national and international guidelines. PE is a non-selective apheresis method with elimination of the entire plasma with subsequent substitution. Selective extracorporeal elimination of autoantibodies and immune complexes with immunoadsorption (IA) is increasingly replacing PE for the treatment of autoimmune neurological diseases due to its equivalent efficacy and advantageous safety profile. The use of IA for MS still remains to become established. The aim of this retrospective investigation was to evaluate efficacy and safety of IA in patients with steroid-unresponsive relapses.

PATIENTS AND METHODS

Fourteen patients with steroid-unresponsive MS relapses were retrospectively analysed. Patients received six IA treatments within 2 weeks using the single-use tryptophan adsorber. Peripheral venous access was used in 11 patients, and 3 patients needed a central line. The plasma volume treated was 2 l per IA. Efficacy criteria were improvement in symptoms of MS relapses which were measured with the Kurtzke scale (EDSS, FS) and visual acuity measurements for patients with optic neuritis.

RESULTS

In 12 of 14 patients the major symptom of MS relapse improved to a clinically relevant extent after tryptophan IA; no patient got worse, corresponding to a response rate of 86%. Mean EDSS and FS in patients with spastic paresis (n=4) and dizziness (n=2) as well as mean visual acuity in patients with optic neuritis (n=8) significantly improved after IA. IA treatments were safe, with good tolerability, and no severe adverse events occurred.

CONCLUSION

Immunoadsorption for the treatment of steroid-unresponsive MS relapses was safe and effective. The response rate was comparable to published results with PE. With IA, in contrast to unselective PE, administration of human plasma products is not necessary, avoiding associated risks.

Plasma exchange in severe attacks of neuromyelitis optica

Background. Neuromyelitis optica (NMO) attacks are poorly controlled by steroids and evolve in stepwise neurological impairments. Assuming the strong humoral response underlying NMO attacks, plasma exchange (PLEX) is an appropriate technique in severe NMO attacks. Objective. Presenting an up-to-date review of the literature of PLEX in NMO. Methods. We summarize the rationale of PLEX in relation with the physiology of NMO, the main technical aspects, and the available studies. Results. PLEX in severe attacks from myelitis or optic neuritis are associated with a better outcome, depending on PLEX delay (“time is cord and eyes”). NMO-IgG status has no influence. Finally, we build up an original concept linking the inner dynamic of the lesion, the timing of PLEX onset and the expected clinical results. Conclusion. PLEX is a safe and efficient add-on therapy in NMO, in synergy with steroids. Large therapeutic trials are required to definitely assess the procedure and define the time opportunity window.

Evidence for the role of B cells and immunoglobulins in the pathogenesis of multiple sclerosis

The pathogenesis of multiple sclerosis (MS) remains elusive. Recent reports advocate greater involvement of B cells and immunoglobulins in the initiation and propagation of MS lesions at different stages of their ontogeny. The key role of B cells and immunoglobulins in pathogenesis was initially identified by studies in which patients whose fulminant attacks of demyelination did not respond to steroids experienced remarkable functional improvement following plasma exchange. The positive response to Rituximab in Phase II clinical trials of relapsing-remitting MS confirms the role of B cells. The critical question is how B cells contribute to MS. In this paper, we discuss both the deleterious and the beneficial roles of B cells and immunoglobulins in MS lesions. We provide alternative hypotheses to explain both damaging and protective antibody responses.

Epstein-Barr and other viral mimicry of autoantigens, myelin and vitamin D-related proteins and of EIF2B, the cause of vanishing white matter disease: massive mimicry of multiple sclerosis relevant proteins by the Synechococcus phage

The Epstein-Barr virus expresses proteins containing numerous short consensi (identical pentapeptides at least, or longer gapped consensi) that are identical to those in 16 multiple sclerosis autoantigens or in the products of multiple sclerosis susceptibility genes. Other viruses implicated in multiple sclerosis also display such mimicry and the Synechococcus phage was identified as a novel and major contributor to this phenomenon. Cyanobacteria hosts of Synechococcus phage favor temperate climes, in line with multiple sclerosis distribution, and bacterial and phage ecology accords closely with multiple sclerosis epidemiology. Bovine, ovine or canine viral proteins were also identified as autoantigen homologues, in line with epidemiological data linking multiple sclerosis to cattle density, sheep contact and dog ownership. Viral proteins align with known autoantigens, other myelin and vitamin D-related proteins and the translation initiation factor EIF2B, which is implicated in vanishing white matter disease. These data suggest that the autoantigens in multiple sclerosis, which causes demyelination in animal models, may be generated by antibodies raised to viral protein homologues. Multiple autoantibodies may cause multiple sclerosis via protein knockdown and immune activation. Their selective removal may be of clinical benefit as already suggested by promising results using plasmapheresis or immunoadsorption in certain multiple sclerosis patients.

B cells and antibodies in MS

Increasing research activities on humoral immune responses involved in the immunopathogenesis of multiple sclerosis (MS) led to a revival of the importance of B cells and antibodies in MS. B cells seem now to play various immunopathogenetic roles in the initiation and propagation of inflammatory demyelinating processes at different disease stages of MS. The biological activities of antibodies in MS is, in general, still less known, although it emerges that antibodies are specifically involved in demyelination or, at least, mirror tissue destruction in the central nervous system. Finally, there is growing evidence that treatments, which specifically target B cells and/or antibodies, are effective in MS and its variants neuromyelitis optica (NMO). This chapter therefore aims to summarize the present knowledge and to outline future directions about the role of B cells and antibodies in research and therapy of MS and NMO.

Contactin-2/TAG-1-directed autoimmunity is identified in multiple sclerosis patients and mediates gray matter pathology in animals

Gray matter pathology is increasingly recognized as an important feature of multiple sclerosis (MS), but the nature of the immune response that targets the gray matter is poorly understood. Starting with a proteomics approach, we identified contactin-2/transiently expressed axonal glycoprotein 1 (TAG-1) as a candidate autoantigen recognized by both autoantibodies and T helper (Th) 1/Th17 T cells in MS patients. Contactin-2 and its rat homologue, TAG-1, are expressed by various neuronal populations and sequestered in the juxtaparanodal domain of myelinated axons both at the axonal and myelin sides. The pathogenic significance of these autoimmune responses was then explored in experimental autoimmune encephalitis models in the rat. Adoptive transfer of TAG-1-specific T cells induced encephalitis characterized by a preferential inflammation of gray matter of the spinal cord and cortex. Cotransfer of TAG-1-specific T cells with a myelin oligodendrocyte glycoprotein-specific mAb generated focal perivascular demyelinating lesions in the cortex and extensive demyelination in spinal cord gray and white matter. This study identifies contactin-2 as an autoantigen targeted by T cells and autoantibodies in MS. Our findings suggest that a contactin-2-specific T-cell response contributes to the development of gray matter pathology.

Neurofascin as a novel target for autoantibody-mediated axonal injury

Axonal injury is considered the major cause of disability in patients with multiple sclerosis (MS), but the underlying effector mechanisms are poorly understood. Starting with a proteomics-based approach, we identified neurofascin-specific autoantibodies in patients with MS. These autoantibodies recognize the native form of the extracellular domains of both neurofascin 186 (NF186), a neuronal protein concentrated in myelinated fibers at nodes of Ranvier, and NF155, the oligodendrocyte-specific isoform of neurofascin. Our in vitro studies with hippocampal slice cultures indicate that neurofascin antibodies inhibit axonal conduction in a complement-dependent manner. To evaluate whether circulating antineurofascin antibodies mediate a pathogenic effect in vivo, we cotransferred these antibodies with myelin oligodendrocyte glycoprotein-specific encephalitogenic T cells to mimic the inflammatory pathology of MS and breach the blood-brain barrier. In this animal model, antibodies to neurofascin selectively targeted nodes of Ranvier, resulting in deposition of complement, axonal injury, and disease exacerbation. Collectively, these results identify a novel mechanism of immune-mediated axonal injury that can contribute to axonal pathology in MS.

[Plasma exchange as a therapeutic option in neurological disorders]

Plasma exchange is a therapeutic procedure commonly used in various neurological disorders. Here we review its current role as a treatment option in diseases of the central and peripheral nervous system.