Clinical efficacy of plasmapheresis in patients with neuromyelitis optica spectrum disorder and effects on circulating anti-aquaporin-4 antibody levels

Comparison of efficacy of plasma exchange versus intravenous immunoglobulin as an add-on therapy in acute attacks of neuromyelitis optica spectrum disorder

INTRODUCTION

Plasma exchange (PE) is considered a Category II option for the treatment of acute attacks and relapse cases of neuromyelitis optica spectrum disorder (NMOSD). However, neurologists are also considering intravenous immunoglobulins (IVIg) as an add-on therapy for this disorder.

AIMS

The aim of this study is to evaluate the efficacy of PE in acute attacks of NMOSD when compared with IVIg, in terms of improvement in the Expanded disability status scale (EDSS) and activities of daily living (ADL) scale score and levels of anti-Aquaporin P4 (AQP4) antibody in seropositive patients.

METHODS

We enrolled 43 NMOSD patients in two groups: Group 1 (n = 29) received steroids and PE, and Group 2 (n = 14) received steroids with IVIg. The baseline EDSS and ADL scores were recorded and compared with scores at the end of therapy, 4 weeks, and 3 months after. Also, anti-AQP4 antibody was measured at baseline and post-therapy in seropositive patients of both groups.

RESULTS

We observed a significant difference in EDSS (p = 0.00) and ADL score (p = 0.00) at day 10 and 3 months in both groups. However, no significant difference in EDSS, as well as ADL score from baseline (p = 0.83; p = 0.25) to 3 months (p = 0.85; p = 0.19), was observed when delta change of score at 3 months was compared across the two groups (p = 0.39; p = 0.52). We observed improved visual acuity in both groups with mild improvement in findings of magnetic resonance imaging at 3 months. We observed a significant decline in AQP4 antibody concentration (at day 10) in group 1 seropositive patients (p = 0.013) with improved EDSS (p = 0.027) and ADL scores (p = 0.026) of these patients.

CONCLUSIONS

PE should be considered as a choice of an add-on therapy in anti-AQP4 antibody-positive NMOSD patients compared with IVIg as it is more effective in reducing antibody concentrations.

Therapeutic plasma exchange for neuromyelitis optica attacks: Evidence and challenges from a real-world cohort from Brazil

Therapeutic plasma exchange (TPE) can improve disability recovery after neuromyelitis optica spectrum disease (NMOSD) attacks, but its effectiveness and safety in Latin-American patients with access barriers and diverse ethnicity is underexplored. We carried out a retrospective cohort study with NMOSD patients that underwent TPE. 84 NMOSD attacks in 68 patients were evaluated. Despite a median 25-day delay from symptom onset to TPE, 65,5% of patients showed significant improvement. Adverse events occurred in 39% of patients, usually transitory and with no fatalities.

Chimeric AQP4-based immunosorbent for highly-specific removal of AQP4-IgG from blood

Anti-aquaporin-4 autoantibodies (AQP4-IgG) are implicated in the pathogenesis of neuromyelitis optica spectrum disorders (NMOSD), and their removal from the blood circulation is considered to be an effective method for acute treatment. An ideal extracorporeal AQP4-IgG removal system should have high specificity, which means that it can selectively remove AQP4-IgG without affecting normal immunoglobulins. However, the conventional tryptophan immobilized column lacks sufficient specificity and cannot achieve this goal. In this study, we successfully prepared a fusion protein chimeric AQP4, which consists of the complete antigenic epitopes of human AQP4 and the constant region of scaffold protein DARPin. Chimeric AQP4 was expressed and purified from Escherichia coli, and then immobilized on agarose gel as a ligand for selective capture of AQP4-IgG immunosorbent. The prepared immunosorbent had a theoretical maximum adsorption capacity of 20.48 mg/g gel estimated by Langmuir isotherm. In vitro plasma perfusion tests demonstrated that the chimeric AQP4 coupled adsorbent had remarkable adsorption performance, and could eliminate more than 85 % of AQP4-IgG under the gel-to-plasma ratio of 1:50. Moreover, it exhibited high specificity because other human plasma proteins were not adsorbed in the dynamic adsorption experiment. These results suggest that the chimeric AQP4 coupled immunosorbent can provide a new approach for specific immunoadsorption (IA) treatment of NMOSD.

Treatment of neuromyelitis optica spectrum disorder: revisiting the complement system and other aspects of pathogenesis

Neuromyelitis optica spectrum disorder (NMOSD) represents a rare neuroimmunological disease causing recurrent attacks and accumulation of permanent disability in affected patients. The discovery of the pathogenic IgG‑1 antibody targeting a water channel expressed in astrocytes, aquaporin 4, constitutes a milestone achievement. Subsequently, multiple pathophysiological aspects of this distinct disease entity have been investigated. Demyelinating lesions and axonal damage ensue from autoantibodies targeting an astroglial epitope. This conundrum has been addressed in the current disease model, where activation of the complement system as well as B cells and interleukin 6 (IL-6) emerged as key contributors. It is the aim of this review to address these factors in light of novel treatment compounds which reflect these pathophysiological concepts in aiming for attack prevention, thus reducing disease burden in patients with NMOSD.

Systematic Review of Treatment Options and Therapeutic Responses for Lesions of the Sella and Orbit: Evidence-Based Recommendations

OBJECTIVE

Inflammatory pathologies of the sella and orbit are rare but require prompt diagnosis to initiate effective treatment. Because uniform recommendations for treatment are currently lacking, we performed an evidence-based review to identify recommendations.

METHODS

We performed a literature search of the PubMed, Embase, and Web of Science databases to identify papers evaluating treatment of inflammatory pathologies of the sella and orbit. We used PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to define recommendations, specifically examining aggregated sample sizes, disease-specific patient follow-up, and clinical trials focused on inflammatory diseases of the sella and orbit.

RESULTS

A total of 169 studies were included and organized by disease pathology. Treatments for various pathologies were recorded. Treatment options included surgery, radiation, steroids, targeted treatments, immunomodulators, intravenous immune globulin, and plasmapheresis. Steroids were the most often employed treatment, second-line management options and timing varied. Pathological diagnosis was highly associated with treatment used. Most evidence were level 3 without available control groups, except for 13 trials in neuromyelitis optica with level 1 or 2 evidence.

CONCLUSIONS

This is the first evidence-based review to provide recommendations on specific treatments for pathologies of the orbit and sella. The reported data may be useful to help guide randomized clinical trials and provide resource for clinical management decisions based on the available evidence.

Immunomodulatory Aspects of Therapeutic Plasma Exchange in Neurological Disorders—A Pilot Study

Therapeutic plasma exchange (TPE) is used for drug-resistant neuroimmunological disorders, but its mechanism of action remains poorly understood. We therefore prospectively explored changes in soluble, humoral, and cellular immune components associated with TPE. We included ten patients with neurological autoimmune disorders that underwent TPE and assessed a panel of clinically relevant pathogen-specific antibodies, total serum immunoglobulin (Ig) levels, interleukin-6 (IL-6, pg/mL), C-reactive protein (CRP, mg/dL), procalcitonin (PCT, µg/L) and major lymphocyte subpopulations (cells/µL). Blood was collected prior to TPE (pre-TPE, baseline), immediately after TPE (post-TPE), as well as five weeks (follow-up1) and 130 days (follow-up2) following TPE. Pathogen-specific antibody levels were reduced by −86% (p < 0.05) post-TPE and recovered to 55% (follow-up1) and 101% (follow-up2). Ig subclasses were reduced by −70–89% (p < 0.0001) post-TPE with subsequent complete (IgM/IgA) and incomplete (IgG) recovery throughout the follow-ups. Mean IL-6 and CRP concentrations increased by a factor of 3–4 at post-TPE (p > 0.05) while PCT remained unaffected. We found no alterations in B- and T-cell populations. No adverse events related to TPE occurred. TPE induced a profound but transient reduction in circulating antibodies, while the investigated soluble immune components were not washed out. Future studies should explore the effects of TPE on particular cytokines and assess inflammatory lymphocyte lineages to illuminate the mode of action of TPE beyond autoantibody removal.

Plasma exchange in inflammatory demyelinating disorders of the central nervous system: reasonable use in the clinical practice

Plasma exchange (PLEX) is a therapeutic apheresis modality in which the plasma is separated from inflammatory factors such as circulating autoreactive immunoglobulins, the complement system, and cytokines, and its therapeutic effect is based on the removal of these mediators of pathological processes. Plasma exchange is well established for various neurological disorders, and it is applied successfully in central nervous system inflammatory demyelinating diseases (CNS-IDD). It mainly modulates the humoral immune system; thus, it has a greater theoretical effect in diseases with prominent humoral mechanisms, such as neuromyelitis optica (NMO). However, it also has a proven therapeutic effect in multiple sclerosis (MS) attacks. Several studies have suggested that patients with severe attacks of CNS-IDD have poor response to steroid therapy but show clinical improvement after the PLEX treatment. Currently, PLEX is generally established only as a rescue therapy for steroid unresponsive relapses. However, there are still research gaps in the literature regarding plasma volume, number of sessions, and how early the apheresis treatment needs to started. Thus, in the present article, we summarize the clinical studies and meta-analyses, especially about MS and NMO, outlining clinical data regarding the experience with therapeutic PLEX in severe attacks of CNS-IDD, the clinical improvement rates, the prognostic factors of a favorable response, and highlighting the likely role of the early apheresis treatment. Further, we have gathered this evidence and suggested a protocol for the treatment of CNS-IDD with PLEX in the routine clinical practice.

Immunoadsorption as maintenance therapy for refractory neuromyelitis optica spectrum disorder

Background

Neuromyelitis optica spectrum disorder (NMOSD) is a rare relapsing autoimmune disease of the central nervous system, affecting mainly optic nerves and spinal cord. NMOSD pathophysiology is associated with anti-aquaporin-4 (AQP4) immunoglobulin G (IgG) autoantibodies. Rapid extracorporeal elimination of autoantibodies with apheresis techniques, such as immunoadsorption (IA), was proven to be an effective treatment of NMOSD attacks. Data on the long-term use of IA to prevent attacks or progression of NMOSD are lacking.

Objectives

The aim of this study was to evaluate efficacy and safety of maintenance IA for preventing recurrence of NMOSD attacks in patients refractory to other immunotherapies.

Design

Case study.

Methods

Retrospective analysis of two female patients with severe NMOSD refractory to conventional immunotherapies was performed. Both patients had responded to tryptophan IA (Tr-IA) as attack therapy and subsequently were treated with biweekly maintenance Tr-IA.

Results

Patient 1 (AQP4-IgG seropositive, age 42 years) had 1.38 attacks of optic neuritis per year within 10.1 years before commencing regular Tr-IA. With maintenance Tr-IA for 3.1 years, one mild attack occurred, which was responsive to steroid pulse therapy. Expanded Disability Status Scale (EDSS) was stable at 5.0. Visual function score of the last eye improved from 3 to 1. Patient 2 (AQP4-IgG seronegative, age 43 years) experienced 1.7 attacks per year, mainly acute myelitis and optic neuritis, during the period of 10.0 years before the start of Tr-IA. During regular Tr-IA treatment, no further NMOSD attack occurred. The patient was clinically stable without any additional immunosuppressive treatment for 5.3 years. EDSS improved from 6.0 to 5.0, and the ambulation score from 7 to 1. Tolerability of Tr-IA was good in both patients. No serious adverse events occurred during long-term clinical trajectories.

Conclusion

Tr-IA was well tolerated as maintenance treatment and resulted in clinical stabilization of two patients with highly active NMOSD, who were refractory to standard drug therapy.

Factors associated with the misdiagnosis of neuromyelitis optica spectrum disorder

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune condition that is associated with severe disability. Approximately 40% of individuals are misdiagnosed with multiple sclerosis (MS) or other diseases. We aimed to define factors that influence the misdiagnosis of people with NMOSD and provide strategies for reducing error rates.

METHODS

A retrospective study was performed involving all people with a confirmed diagnosis of NMOSD within a single academic institution. Comprehensive clinical timelines were constructed for each individual that included presenting symptoms, provider type and timing of evaluations, aquaporin 4-IgG (AQP4) results, and MRI scans. Two-sample comparisons of continuous and categorial variables were performed for people accurately diagnosed with NMOSD and those originally misdiagnosed with another medical condition. A subanalysis of only AQP4-IgG positive people was also performed.

RESULTS

The study cohort included 199 people fulfilling International Panel criteria for NMOSD with 71 people (62 female; mean age at first symptom presentation (standard deviation (SD)) = 32.8 years (y) (SD 16.1)) being initially misdiagnosed and 128 people (106 female; 41.14y (SD 15.41)) who were accurately diagnosed. Of the 199 people with NMOSD, 166 had a positive serostatus. Identified factors associated with misdiagnosis, regardless of AQP4-IgG serostatus, were the presence of protracted nausea/vomiting/hiccups without any accompanying neurological symptoms, 23 (32.4%) versus 16 (12.5%) (p = 0.001), a longer median (range) time to see a neuroimmunology specialist 4.2y (0.14-31.8) versus 0.5y (0.0-21.2) (p<0.0001), and a delay in acquiring an MRI study, 4.7y (0.0-27.3) versus 0.3y (0.0-20.2) (p<0.0001). A greater proportion of people misdiagnosed were identified with a negative live-cell based AQP4-IgG serum test result, 13/13 (100%) versus 22/114 (19.3%) (p<0.0001). Additionally, the mean (SD) time between a first negative and successive live-cell based AQP4-IgG positive test result was greater for people misdiagnosed with another condition, 3.9y (SD 5.0) versus 1.5y (SD 2.1) (p = 0.01). Although not significant between groups, a rash was also reported in 63/199 people with NMOSD, with 31/63 having an anti-nuclear antibody titer ≥ 1:160.

CONCLUSION

Defined factors can help guide both generalists and specialists in the pursuit of strategies aimed at efficiently diagnosing those with NMOSD such that effective care can be delivered.

Safety and efficacy of plasma exchange treatment in children with AQP4-IgG positive neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD), a severe demyelinating disease, is rare among children. Plasma exchange (PE) is widely used as a salvage therapy for severe and corticosteroid-unresponsive patients with NMOSD. Presently, there are limited studies on the safety and efficacy of PE in children with NMOSD. Herein, we report the case of six children with NMOSD who received PE along with the outcomes and adverse events. All six children (female, age at onset 4 years 9 months-13 years 2 months) were AQP4-IgG positive and received standard PE using the COM.TEC Cell Separator. The interval between NMOSD onset and PE was 29 days (range 10-98). Only one patient (P3) who received PE 10 days after acute exacerbations exhibited clinical improvement. Her left visual acuity increased from 0.06 to 0.6 (spectacle-corrected visual acuity was 1.0) and her EDSS score decreased from 4 to 3 points. The other five patients had no clinical improvement and no EDSS scores changes after PE. Adverse events included rashes (P1, P3), acute non-occlusive thrombosis of the internal jugular vein (P1), and thrombocytopenia (P2). In conclusion, the timing of PE initiation as a rescue therapy for severe and corticosteroid-unresponsive pediatric AQP4-IgG positive NMOSD may be crucial to treatment efficacy, and early initiation of PE may be associated with a better outcome. Furthermore, PE has the potential risk for clinically significant adverse effects that should be considered before initiating the therapy and should be weighed against potential benefits.

Paraneoplastic Neuromyelitis Optica Spectrum Disorder Related to Glucose-regulated Protein 78 (GRP78) Autoantibodies in a Patient with Lynch Syndrome-associated Colorectal Cancer

Neuromyelitis optica spectrum disorders have been previously reported in a paraneoplastic context, although there is no clear consensus on their pathogenesis. We herein report a case of aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder in a 64-year-old woman with colorectal cancer. She underwent tumor resection, resulting in serum aquaporin-4 antibody titers subsequently becoming negative. Serum samples were also positive for glucose-regulated protein 78 antibody, which has recently been suggested to be a novel factor in the disruption of the blood-brain barrier. Serological and pathological investigations in this case highlight the role and involvement of aquaporin-4 and glucose-regulated protein 78 antibodies in paraneoplastic conditions.

Current view on the diagnosis and treatment of neuromyelitis optica spectrum disorders exacerbations

Irreversible neurological deficit and disability in neuromyelitis optica spectrum disorders (NOSD) are formed as a result of exacerbations, which are often life-threatening. Timely diagnosis and treatment of exacerbations is a key task in the management of this category of patients. A unified structured approach to the diagnosis and treatment of NOSD exacerbations has not been developed. The purpose of this article is to analyze the scientific literature data on this issue in order to optimize the diagnostics and treatment of NOSD exacerbations in everyday clinical practice. 

Eculizumab for acute relapse of neuromyelitis optica spectrum disorder: Case report

Introduction

Eculizumab has been shown to be an effective and typically well-tolerated medication in the treatment of neuromyelitis optica spectrum disorder (NMOSD) in maintaining disease remission in patients who are aquaporin-4 water channel autoantibody (AQP4-IgG) seropositive. The efficacy of eculizumab in an acute relapse of NMOSD however is still under review.

Case

We describe a 46 year-old female who presented with acute left monocular vision loss on a background of bilateral optic neuritis treated 15 years prior as suspected NMOSD. She had very poor vision from the right eye (6/60). On presentation she was not on any long-term immunosuppressive agents. Her serum was positive for AQP4-IgG and MRI brain and spine demonstrated areas of demyelination in the corpus callosum and thoracic spine. She was treated with high dose intravenous methylprednisolone and underwent plasmapheresis for five consecutive days, but continued to clinically deteriorate with ongoing blindness in her left eye (light perception only). She was subsequently administered eculizumab with weaning oral corticosteroids. Clinically her vision improved to counting fingers and she remains on maintenance eculizumab infusions in the community. At 3 months, there is a steady improvement but still significant loss of central vision from that eye.

Conclusion

The utility of eculizumab in NMOSD may assist with treating acute episodes. This theoretically accords with the mode of action in inhibiting conversion of C5–C5a/b, perhaps arresting the acute inflammatory process in this disease. Given that disease burden and mortality in NMOSD is almost entirely related to relapses, increased use of eculizumab acutely could potentially aid recovery from an attack in very severe attacks, and therefore minimize immediate stepwise accrual of disability.

Neuromyelitis Optica Spectrum Disorders

PURPOSE OF REVIEW

This article reviews the cardinal clinical features, distinct immunopathology, current diagnostic criteria, relapse-related risk factors, emerging biomarkers, and evolving treatment strategies pertaining to neuromyelitis optica spectrum disorders (NMOSD).

RECENT FINDINGS

The discovery of the pathogenic aquaporin-4 (AQP4)-IgG autoantibody and characterization of NMOSD as an autoimmune astrocytopathy have spearheaded the identification of key immunologic therapeutic targets in this disease, including but not limited to the complement system, the interleukin 6 (IL-6) receptor, and B cells. Accordingly, four recent randomized controlled trials have demonstrated the efficacy of three new NMOSD therapies, namely eculizumab, satralizumab, and inebilizumab.

SUMMARY

Currently, NMOSD poses both diagnostic and treatment challenges. It is debated whether individuals who are seropositive for myelin oligodendrocyte glycoprotein (MOG)-IgG belong within the neuromyelitis optica spectrum. This discussion is fueled by disparities in treatment responses between patients who are AQP4-IgG seropositive and seronegative, suggesting different immunopathologic mechanisms may govern these conditions. As our understanding regarding the immune pathophysiology of NMOSD expands, emerging biomarkers, including serum neurofilament light chain and glial fibrillary acidic protein (GFAP), may facilitate earlier relapse detection and inform long-term treatment decisions. Future research focal points should include strategies to optimize relapse management, restorative treatments that augment neurologic recovery, and practical solutions that promote equitable access to approved therapies for all patients with NMOSD.

Therapeutic plasma exchange for optic neuritis attacks in patients with neuromyelitis optica spectrum disorders

BACKGROUND

Optic neuritis (ON) cause several sequela. Aggressive treatment with plasma exchange (TPE) is an option. This study describe improvement and safety outcomes with TPE.

METHODS

We recruited adults with ON in neuromyelitis optica spectrum disorders (NMOSD) patients treated with TPE. The primary outcome was an improvement in the visual acuity scale (VOS). We described the data and used multivariate logistic regression to identify factors associated with response.

RESULTS

83 patients received 558 TPE sessions. Mean age 40.9 years (±13.7 years); 73.5% women, 50.1% first attack, and 10.7% bilateral. Median VOS: 5 (range [R], 2-7). Median time between onset and TPE was 8 days (R, 1-32. By Keegan's criteria 82.4% experience improvement, 78.3% improve in at least 1 point in VOS. Age and pre-TPE VOS were related with improvement. Low fibrinogen occurs in 26% sessions.

CONCLUSION

TPE is effective and safety for ON. There is a need for a clinical trial using a therapeutic equivalent.

Optic Neuritis in the Era of NMOSD and MOGAD: A Survey of Practice Patterns in Singapore

PURPOSE

The Optic Neuritis Treatment Trial was a landmark study with implications worldwide. In the advent of antibody testing for neuromyelitis optica spectrum disease (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), emerging concepts, such as routine antibody testing and management, remain controversial, resulting mostly from studies in White populations. We evaluate the practice patterns of optic neuritis investigation and management by neuro-ophthalmologists and neurologists in Singapore.

DESIGN

21-question online survey consisting of 4 clinical vignettes.

METHODS

The survey was sent to all Singapore Medical Council- registered ophthalmologists and neurologists who regularly manage patients with optic neuritis.

RESULTS

Forty-two recipients (17 formally trained neuro-ophthalmol-ogists [100% response rate] and 25 neurologists) responded. Participants opted for routine testing of anti-aquaporin-4 antibodies (88.1% in mild optic neuritis and 97.6% in severe optic neuritis). Anti-MOG antibodies were frequently obtained (76.2% in mild and 88.1% in severe optic neuritis). Plasmapheresis was rapidly initiated (85.7%) in cases of nonresponse to intravenous steroids, even before obtaining anti-aquaporin-4 or anti-MOG serology results. In both NMOSD and MOGAD, oral mycophenolate mofetil was the preferred option if chronic immunosuppression was necessary. Steroids were given for a longer duration and tapered more gradually than in idiopathic optic neuritis cases.

CONCLUSIONS

Serological testing for NMOSD and MOGAD is considered as a routine procedure in cases of optic neuritis in Singapore, possibly due to local epidemiological features of these conditions. Chronic oral immunosuppression is preferred for the long term, but further research is necessary to establish the efficacy and cost-effectiveness of these practices.

Efficacy and safety of plasma exchange or immunoadsorption for the treatment of option neuritis in demyelinating diseases: A systematic review and meta-analysis

BACKGROUND

There are no systematic reviews yet that evaluated the effects of PE/IA in patients with optic neuritis (ON) in demyelinating diseases. A meta-analysis of available study is needed to further explore the value of plasma exchange (PE) or immunoadsorption (IA) in treating ON in demyelinating diseases.

METHODS

All relevant articles published on PubMed, Web of Science, Cochrane Library, Embase, China National Knowledge Infrastructure (CNKI), VIP Database, Wanfang, Sinomed and ophthalmology professional websites were searched. Study characteristics, demographic characteristics, clinical features and outcome measures were extracted. Response rate, adverse events (AE) rate, serious adverse event (SAE) rate, the log of the minimum angle of resolution (logMAR), visual outcome scale (VOS) and expanded disability status scales (EDSS) were evaluated using a random-effects model.

RESULTS

35 studies were included between 1985 and 2020, containing 1191 patients. The response rates of PE and IA in acute attack of ON were 68% and 82% respectively. LogMAR (-0.60 to - 1.42) and VOS (-1.10 to -1.82) had been significantly improved from within 1 month to more than 1 month after PE treatment. Besides, we found that logMAR improved 1.78, 0.95 and 0.38, respectively ,when the time from symptom onset to the first PE/IA was less than 21 days, 21-28 days, and more than 28 days. The pooled mean difference of EDSS was -1.14.Adverse effects rate in patients with PE or IA were 0.20 and 0.06, respectively.

CONCLUSION

The meta-analysis provided evidence that PE/IA treatment was an effective and safe intervention, and it is recommended that early initiation of PE/IA treatment is critical.

Hope for patients with neuromyelitis optica spectrum disorders - from mechanisms to trials

Neuromyelitis optica spectrum disorder (NMOSD) is a rare inflammatory CNS disease that primarily manifests as relapsing episodes of severe optic neuritis and myelitis. Diagnosis of NMOSD is supported by the detection of IgG autoantibodies that target the aquaporin 4 (AQP4) water channel, which, in the CNS, is an astrocyte-specific protein. AQP4 antibody binding leads to AQP4 internalization, complement-dependent and antibody-dependent cellular cytotoxicity, and water channel dysfunction. Cumulative attack-related injury causes disability in NMOSD, so the prevention of attacks is expected to prevent disability accrual. Until recently, no regulator-approved therapies were available for NMOSD. Traditional immunosuppressant therapies, including mycophenolate mofetil, azathioprine and rituximab, were widely used but their benefits have not been assessed in controlled studies. In 2019 and 2020, five phase II and III randomized placebo-controlled trials of four mechanism-based therapies for NMOSD were published and demonstrated that all four effectively prolonged the time to first relapse. All four drugs were monoclonal antibodies: the complement C5 antibody eculizumab, the IL-6 receptor antibody satralizumab, the B cell-depleting antibody inebilizumab, which targets CD19, and rituximab, which targets CD20. We review the pathophysiology of NMOSD, the rationale for the development of these mechanism-based drugs, the methodology and outcomes of the five trials, and the implications of these findings for the treatment of NMOSD.

Neuromyelitis optica spectrum disorders: from pathophysiology to therapeutic strategies

Neuromyelitis optica (NMO) is a chronic inflammatory autoimmune disease of the central nervous system (CNS) characterized by acute optic neuritis (ON) and transverse myelitis (TM). NMO is caused by a pathogenic serum IgG antibody against the water channel aquoporin 4 (AQP4) in the majority of patients. AQP4-antibody (AQP4-ab) presence is highly specific, and differentiates NMO from multiple sclerosis. It binds to AQP4 channels on astrocytes, triggering activation of the classical complement cascade, causing granulocyte, eosinophil, and lymphocyte infiltration, culminating in injury first to astrocyte, then oligodendrocytes followed by demyelination and neuronal loss. NMO spectrum disorder (NMOSD) has recently been defined and stratified based on AQP4-ab serology status. Most NMOSD patients experience severe relapses leading to permanent neurologic disability, making suppression of relapse frequency and severity, the primary objective in disease management. The most common treatments used for relapses are steroids and plasma exchange.Currently, long-term NMOSD relapse prevention includes off-label use of immunosuppressants, particularly rituximab. In the last 2 years however, three pivotal clinical trials have expanded the spectrum of drugs available for NMOSD patients. Phase III studies have shown significant relapse reduction compared to placebo in AQP4-ab-positive patients treated with satralizumab, an interleukin-6 receptor (IL-6R) inhibitor, inebilizumab, an antibody against CD19⁺ B cells; and eculizumab, an antibody blocking the C5 component of complement. In light of the new evidence on NMOSD pathophysiology and of preliminary results from ongoing trials with new drugs, we present this descriptive review, highlighting promising treatment modalities as well as auspicious preclinical and clinical studies.

Treatment of Neuromyelitis Optica Spectrum Disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune central nervous system (CNS) inflammatory disorder that can lead to serious disability and mortality. Females are predominantly affected, including those within the reproductive age. Most patients develop relapsing attacks of optic neuritis; longitudinally extensive transverse myelitis; and encephalitis, especially brainstem encephalitis. The majority of NMOSD patients are seropositive for IgG autoantibodies against the water channel protein aquaporin-4 (AQP4-IgG), reflecting underlying aquaporin-4 autoimmunity. Histological findings of the affected CNS tissues of patients from in-vitro and in-vivo studies support that AQP4-IgG is directly pathogenic in NMOSD. It is believed that the binding of AQP4-IgG to CNS aquaporin-4 (abundantly expressed at the endfoot processes of astrocytes) triggers astrocytopathy and neuroinflammation, resulting in acute attacks. These attacks of neuroinflammation can lead to pathologies, including aquaporin-4 loss, astrocytic activation, injury and loss, glutamate excitotoxicity, microglial activation, neuroinflammation, demyelination, and neuronal injury, via both complement-dependent and complement-independent pathophysiological mechanisms. With the increased understanding of these mechanisms underlying this serious autoimmune astrocytopathy, effective treatments for both active attacks and long-term immunosuppression to prevent relapses in NMOSD are increasingly available based on the evidence from retrospective observational data and prospective clinical trials. Knowledge on the indications and potential side effects of these medications are essential for a clear evaluation of the potential benefits and risks to NMOSD patients in a personalized manner. Special issues such as pregnancy and the coexistence of other autoimmune diseases require additional concern and meticulous care. Future directions include the identification of clinically useful biomarkers for the prediction of relapse and monitoring of the therapeutic response, as well as the development of effective medications with minimal side effects, especially opportunistic infections complicated by long-term immunosuppression.

Magnetic resonance imaging in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease of the central nervous system (CNS) associated with antibodies to aquaporin-4 (AQP4), which has distinct clinical, radiological and pathological features, but also has some overlap with multiple sclerosis and myelin oligodendrocyte glycoprotein (MOG) antibody associated disease. Early recognition of NMOSD is important because of differing responses to both acute and preventive therapy. Magnetic resonance (MR) imaging has proved essential in this process. Key MR imaging clues to the diagnosis of NMOSD are longitudinally extensive lesions of the optic nerve (more than half the length) and spinal cord (three or more vertebral segments), bilateral optic nerve lesions and lesions of the optic chiasm, area postrema, floor of the IV ventricle, periaqueductal grey matter, hypothalamus and walls of the III ventricle. Other NMOSD-specific lesions are denoted by their unique morphology: heterogeneous lesions of the corpus callosum, 'cloud-like' gadolinium (Gd)-enhancing white matter lesions and 'bright spotty' lesions of the spinal cord. Other lesions described in NMOSD, including linear periventricular peri-ependymal lesions and patch subcortical white matter lesions, may be less specific. The use of advanced MR imaging techniques is yielding further useful information regarding focal degeneration of the thalamus and optic radiation in NMOSD and suggests that paramagnetic rim patterns and changes in normal appearing white matter are specific to MS. MR imaging is crucial in the early recognition of NMOSD and in directing testing for AQP4 antibodies and guiding immediate acute treatment decisions. Increasingly, MR imaging is playing a role in diagnosing seronegative cases of NMOSD.

Neuromyelitis Optica Spectrum Disorder Treatment-Current and Future Prospects

Neuromyelitis optica (NMO) is an immune-mediated demyelinative disorder of the central nervous system affecting mainly the optical nerves and the spinal cord. The recurrent course of the disease, with exacerbations and incomplete remissions, causes accumulating disability, which has a profound impact upon patients’ quality of life. The discovery of antibodies against aquaporin 4 (AQP4) and their leading role in NMO etiology and the formulation of diagnostic criteria have improved appropriate recognition of the disease. In recent years, there has been rapid progress in understanding the background of NMO, leading to an increasing range of treatment options. On the basis of a review of the relevant literature, the authors present currently available therapeutic strategies for NMO as well as ongoing research in this field, with reference to key points of immune-mediated processes involved in the background of the disease.

Efficacy of plasma exchange in acute attacks of neuromyelitis optica spectrum disorders: A systematic review and meta-analysis

BACKGROUND

Plasma exchange (PE) has usually to be considered as a rescue therapy when intravenous corticosteroids is insufficient in acute attacks of neuromyelitis optica spectrum disorders (NMOSD). The efficacy of PE has not been quantified. This system review and meta-analysis was aimed to evaluate the efficacy of PE therapy in acute attacks of NMOSD.

METHODS

Studies evaluating the efficacy of PE in patients with NMOSD were identified from PubMed and Embase. Changes of Expanded Disability Status Scale (EDSS) score between before and after PE therapy, and the rate of response to PE, were defined as the main efficacy outcomes. Meta-regression was performed to identify the sources of heterogeneity. Subgroup meta-analysis were performed based on the interval of initiation PE after attack onset and AQP4-IgG serostatus of patients.

RESULTS

Twenty-four studies containing 528 patients with NMOSD were included in this meta-analysis. As a rescue therapy when patients failed to respond to intravenous corticosteroids (PE rescue), PE treatment resulted in a reduction in the mean EDSS score by 1.69 (95% CI: 0.88-2.50), with a response rate of 75%(95%CI: 66%-83%). As a first-line therapy being used alone or simultaneously with intravenous corticosteroids (PE first-line), PE resulted in a reduction in the mean EDSS score by 2.34 (95% CI: 1.69-2.98), with a response rate of 71%(95%CI: 44%-93%). Overall, PE resulted in a reduction in the mean EDSS score by 1.83 (95% CI: 1.19-2.47), with a response rate of 74% (95%CI: 66%-82%). Subgroup analysis suggested that earlier PE initiation and AQP4-IgG seronegative patients seemed to be associated with a superior response to PE therapy.

CONCLUSION

Plasma exchange, whether used as rescue or as first-line therapy, is an effective therapeutic method in patients during acute attacks of NMOSD.

Acute Disseminated Encephalomyelitis: Current Perspectives

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated central nervous system (CNS) disorder, characterized by polyfocal symptoms, encephalopathy and typical magnetic resonance imaging (MRI) findings, that especially affects young children. Advances in understanding CNS neuroimmune disorders as well as the association of myelin oligodendrocyte glycoprotein antibody (MOG-Ab) with both monophasic and recurrent forms of ADEM have led to new insights into its definition, management and outcome. In this review, we aim to provide an update based on current epidemiologic, clinical, radiological and immunopathological aspects and clinical outcome of ADEM.

Double Filtration Plasmapheresis Treatment of Refractory Multiple Sclerosis Relapsed on Fingolimod: A Case Report

Double filtration plasmapheresis (DFPP) is an emerging semi-selective apheretic method for treating immuno-mediated neurological diseases. Here we report the first case of steroid-refractory relapsed multiple sclerosis (MS) on Fingolimod (FTY), treated effectively by this technique, in a 37-year-old woman. This condition is thought to be caused by soluble inflammatory species, but its demyelinating pattern is unknown; moreover, despite megadoses of intravenous 6-methyl prednisolone, it induces severe neurological deterioration, but dramatically responded to DFPP in our patient. The clinical improvement was driven by a strong DFPP-induced anti-inflammatory effect, with significant reduction of C3/C4 components, total gamma globulin concentrations (IgG), and gamma-fibrinogen (FGG), resulting in a brain pseudoatrophy phenomenon. Our findings are: first, the steroid-refractory relapsed MS on FTY, however serious, can be treated with DFPP; second, given the good clinical improvement due to the DFPP-induced neuroinflammatory components removal, this clinical condition can be associated with a Lucchinetti pattern II of demyelination.

Neuromyelitis optica

Neuromyelitis optica (NMO; also known as Devic syndrome) is a clinical syndrome characterized by attacks of acute optic neuritis and transverse myelitis. In most patients, NMO is caused by pathogenetic serum IgG autoantibodies to aquaporin 4 (AQP4), the most abundant water-channel protein in the central nervous system. In a subset of patients negative for AQP4-IgG, pathogenetic serum IgG antibodies to myelin oligodendrocyte glycoprotein, an antigen in the outer myelin sheath of central nervous system neurons, are present. Other causes of NMO (such as paraneoplastic disorders and neurosarcoidosis) are rare. NMO was previously associated with a poor prognosis; however, treatment with steroids and plasma exchange for acute attacks and with immunosuppressants (in particular, B cell-depleting agents) for attack prevention has greatly improved the long-term outcomes. Recently, a number of randomized controlled trials have been completed and the first drugs, all therapeutic monoclonal antibodies, have been approved for the treatment of AQP4-IgG-positive NMO and its formes frustes.

Use of therapeutic plasma exchange for pediatric neurological diseases

Therapeutic plasma exchange is used to treat neurological diseases in the pediatric population. Since its first use in pediatric patients with hepatic coma in the form of manual whole blood exchange, therapeutic plasma exchange has been increasingly used to treat these disorders of the nervous system. This expansion is a result of improved techniques and apheresis instruments suitable for small children, as well as the recognition of its applicability to many diseases in the pediatric population. This review provides a historical overview of the use of therapeutic apheresis in children and highlights the most common applications for therapeutic plasma exchange to treat neurological disorders in children.

Effect of plasma exchange in neuromyelitis optica spectrum disorder: A systematic review and meta-analysis

OBJECTIVE

To conduct systematic review and meta-analysis for the efficacy of therapeutic plasma exchange (TPE) for neuromyelitis optica spectrum disorder (NMOSD) with an acute attack.

METHODS

Systematic review was performed using EMBASE and OVID/Medline database. The eligible studies must be the studies of NMOSD patients treated with TPE during the acute phase. They must report treatment outcomes using either Expanded Disability Status Scale (EDSS) or visual acuity (VA) before and after the therapy. Pooled mean difference (MD) was then calculated by combining MDs of each study using the random-effects model.

RESULTS

Fifteen studies were identified; eleven with 241 NMOSD patients reported EDSS outcome and four studies with 103 NMOSD reported visual outcomes. The meta-analysis demonstrated a significantly decreased in EDSS after TPE treatment for NMOSD with an acute attack with the pooled MD of 0.83 (95% CI, 0.26-1.40; I² 69%) comparing pretreatment to immediate posttreatment and 2.13 (95% CI, 1.55-2.70; I² 31%) comparing pretreatment to posttreatment at 6 months to 1-year follow-up. Unfortunately, only one of the four studies evaluating visual outcomes reported standard deviation in association with mean LogMAR; therefore, the meta-analysis cannot be conducted. Nonetheless, all studies consistently demonstrated the benefit of TPE with improved VA and/or LogMAR after treatment.

INTERPRETATION

This systematic review and meta-analysis showed the benefit of TPE during the NMOSD attack with a significantly improved disability status immediately after treatment and during follow-up.

NMOSD acute attack: Understanding, treatment and innovative treatment prospect

Neuromyelitis optica spectrum disorder (NMOSD) is a group of severe inflammatory demyelinating disorders of the central nervous system that involves the optic nerve and spinal cord. Currently the therapeutic options for an acute attack in NMOSD are limited and rarely characterized in clinical studies. This review discussed the overall characteristics of acute attack of NMOSD, related risk factor, prognosis and management. Considering the huge unmet needs and the emergence of new therapeutic targets, we also reviewed innovative treatments that might alleviate attack damage, along with the challenges to evaluate new drug for acute attack in NMOSD.

Do modern therapies change natural history of Neuromyelitis optica?

Neuromyelitis optica spectrum disorder (NMOSD) is an uncommon antibody-mediated disease of the central nervous system. Approximately 75% of patients have antibodies against aquaporin-4, a water channel expressed on astrocytes. Untreated, approximately 50% of NMOSD patients will be wheelchair users and blind, and a third will have died within 5 years of their first attack. Unlike multiple sclerosis, a progressive clinical course is very unusual and the accrual of disability is related to relapses. Aggressive treatment of attacks and highly efficient maintenance therapies to prevent attacks are therefore crucial to prevent residual disability. In this article, we review how high dose steroids and most importantly apheresis and modern therapies implicating B cell depletion, inhibition of complement and IL-6 reception are effective to change its natural history. We will emphasize the results of three recent double blind randomized controlled studies using monoclonal antibodies allowing strong hope to modify natural history of NMOSD.

Monoclonal Antibody-Based Treatments for Neuromyelitis Optica Spectrum Disorders: From Bench to Bedside

Neuromyelitis optica (NMO)/NMO spectrum disorder (NMOSD) is a chronic, recurrent, antibody-mediated, inflammatory demyelinating disease of the central nervous system, characterized by optic neuritis and transverse myelitis. The binding of NMO-IgG with astrocytic aquaporin-4 (AQP4) functions directly in the pathogenesis of >60% of NMOSD patients, and causes astrocyte loss, secondary inflammatory infiltration, demyelination, and neuron death, potentially leading to paralysis and blindness. Current treatment options, including immunosuppressive agents, plasma exchange, and B-cell depletion, are based on small retrospective case series and open-label studies. It is noteworthy that monoclonal antibody (mAb) therapy is a better option for autoimmune diseases due to its high efficacy and tolerability. Although the pathophysiological mechanisms of NMOSD remain unknown, increasingly, therapeutic studies have focused on mAbs, which target B cell depletion, complement and inflammation cascade inactivation, blood-brain-barrier protection, and blockade of NMO-IgG-AQP4 binding. Here, we review the targets, characteristics, mechanisms of action, development, and potential efficacy of mAb trials in NMOSD, including preclinical and experimental investigations.

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.

Protein spectrum changes in exosomes after therapeutic plasma exchange in patients with neuromyelitis optica

INTRODUCTION

Neuromyelitis optica (NMO) is an autoimmune disease with a high rate of blindness and positive for the detection of aquaporin-4 antibody (AQP4) in most patients. NMO acute attacks are managed by high-doses of intravenous methylprednisolone followed by oral taper, and if symptoms fail to resolve, therapeutic plasma exchange (TPE) is added. TPE can remove pathological antibodies and inflammatory factors leading to clinical improvement.

METHODS

A total of 40 TPE fluid collections from the first to fifth TPE treatments were obtained from eight patients. Exosomes were isolated by ultracentrifugation. Mass spectrometry analyses were used to compare protein change in TPE fluid collection exosomes after the first to the fifth TPE treatments in these patients.

RESULTS

We detected 647 exosome proteins through data-independent acquisition analysis. It was found that some unknown functional antibody fragments and complement pathway proteins decreased after TPE treatment. The results revealed a significant involvement of the following two key pathways: the primary immunodeficiency and systemic lupus erythematosus that may be associated with NMO pathophysiology and TPE treatment efficacy (P < .05). A series of complement proteins may contribute to NMO; in addition, the following proteins increased with plasma exchange: complement factor H-related protein 5, bridging integrator 2, neuroplastin, pigment epithelium-derived factor, ficolin-1, extracellular matrix protein 1, and fatty acid-binding protein 5.

CONCLUSION

Our study may provide a new perspective on the pathogenesis and treatment efficacy of NMO.

A pilot study comparing treatments for severe attacks of neuromyelitis optica spectrum disorders: Intravenous methylprednisolone (IVMP) with add-on plasma exchange (PLEX) versus simultaneous ivmp and PLEX

BACKGROUND

Our previous retrospective study demonstrated that NMOSD patients with an acute attack who did not respond to IVMP alone, however, showed further significant improvement after treatment with PLEX at 6 month-follow-up.

OBJECTIVE

To compare the efficacy between treatments with intravenous methylprednisolone (IVMP) with subsequent add-on plasma exchange (PLEX) and a combination of simultaneous IVMP and PLEX in neuromyelitis optica spectrum disorders (NMOSD) patients with a severe acute attack.

METHOD

We conducted a prospective, randomized, controlled, pilot study of the treatments for a severe acute attack in NMOSD patients.

RESULTS

There were eleven AQP4-positive NMOSD patients in the study. One received only IVMP, five received IVMP with subsequent add-on PLEX treatment, and the other five received simultaneous IVMP and PLEX treatment. The attacks comprised myelitis (57.1%) and optic neuritis (42.9%). Both treatments with IVMP followed by subsequent add-on PLEX when needed (not-respond to IVMP treatment) and a combination treatment of simultaneous IVMP+PLEX from the outset showed clinical improvement measured by EDSS at 6 months follow-up, compared to those at the attacks (p-value = 0.07 in IVMP add-on PLEX group and p-value = 0.05 in IVMP+PLEX group), respectively. Although, a trend of a better outcome stratified by EDSS toward early PLEX initiation with IVMP+PLEX treatment was observed at 6 months follow-up, however not significantly.

CONCLUSION

Early treatment with PLEX should be encouraged especially in NMOSD with a severe acute attack.

Plasma Exchange as a First Line Therapy in Acute Attacks of Neuromyelitis Optica Spectrum Disorders

Background and Aims:

Neuromyelitis optica spectrum disorder (NMOSD) is a demyelinating disorder of central nervous system with deleterious effects. At present Intravenous corticosteroids are used for the relapse as the first line of treatment, but with only a class evidence III-IV. Having an underlying humoral immune mechanism in the pathogenesis of NMOSD and as it is rightly said that “Time is Cord and Eyes”, delaying the time to start plasma exchange (PLEX) awaiting favorable outcome in response to corticosteroids is detrimental for the patient. Hence, PLEX may be a promising first line therapeutic approach in the management of severe attacks of NMOSD. The aim of this study is to evaluate the efficacy of PLEX as the first line of treatment for the acute attacks in patients with NMOSD that is being largely used as an add-on therapy for more than 10 years, and also to define the time opportunity window for the starting of PLEX.

Methods:

The study analysed the therapeutic efficacy and safety profile of PLEX as a first line therapy in 30 patients diagnosed with NMOSD over a period of 30 months. PLEX was performed using a Hemonetics Mobile Collection System plus machine with due written consent including the risks and benefits of the treatment that is being proposed to the patient/relative in their own language.

Results:

A total of 30 patients were analysed, out of which 16 were females and rest males. 85% of the patients were in the age group of 25-35 years. All the patients had severe Expanded Disability Status Scale (EDSS) scores at the baseline, and 73.33% showed significant improvement following PLEX. The only predictor of good outcome was the time to PLEX i.e shorter delay betters the outcome.

Conclusion:

The study ascertained the importance of early PLEX as a therapeutic intervention in severe attacks of NMOSD irrespective of their Anti-Aquaporin 4 (AQP4) antibody status.

Prognostic indicators of improvement with therapeutic plasma exchange in pediatric demyelination

OBJECTIVES

To determine the safety and clinical benefit of therapeutic plasma exchange (TPE) as rescue therapy in children with acute inflammatory demyelinating CNS syndromes and to identify baseline prognostic indicators of treatment improvement.

METHODS

This single-center retrospective pediatric cohort included all consecutive patients admitted to our hospital over the period from 2003 to 2017 because of a steroid-refractory acute CNS event presumed to be inflammatory who required TPE. Functional status assessment to identify improvement included the following performance category scales: visual outcome, bladder control, gait, and Expanded Disability Status Scale (EDSS). These assessments were performed before and after TPE in every patient.

RESULTS

Sixty-five children requiring TPE to treat 78 CNS attacks were included for analysis. Median age at TPE was 10.5 years (1.9-18 years); 45% were girls. Seropositivity (aquaporin-4 water channel-immunoglobulin G [IgG] or myelin oligodendrocyte glycoprotein-IgG) was found in 20 of 42 (48%) patients. Attack phenotypes leading to TPE were optic neuritis (ON) in 42%, longitudinally extensive transverse myelitis (LETM) in 31%, ON + LETM in 15%, and other combined syndromes in 11%. Overall, moderate to marked neurologic improvement was observed in 72% of children at the end of TPE and in 88.5% at 6 months of follow-up. Lower baseline scores on the EDSS, visual outcome, and gait scales were found to be independent prognostic indicators of treatment benefit. Sex, age at onset and at TPE, attack phenotype, disease duration, and time from attack onset to TPE initiation were not significantly associated with treatment outcome. Adverse events were observed in 31 of 524 (5.9%) procedures, being severe in 4.

CONCLUSIONS

TPE was an effective rescue therapy associated with functional improvement. No therapeutic window for TPE initiation was identified in this pediatric cohort. Overall frequency of adverse events was low; however, serious events should be anticipated and avoided.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that for children with acute inflammatory demyelinating CNS syndromes, TPE leads to functional improvement.

Differences in the Reponses to Apheresis Therapy of Patients With 3 Histopathologically Classified Immunopathological Patterns of Multiple Sclerosis

Importance

Plasma exchange and immunoadsorption are second-line apheresis therapies for patients experiencing multiple sclerosis relapses. Early active multiple sclerosis lesions can be classified into different histopathological patterns of demyelination. Pattern 1 and 2 lesions show T-cell- and macrophage-associated demyelination, and pattern 2 is selectively associated with immunoglobulin and complement deposits, suggesting a humoral immune response. Pattern 3 lesions show signs of oligodendrocyte degeneration. Thus it is possible that pathogenic heterogeneity might predict therapy response.

Objective

To evaluate the apheresis response in relation to histopathologically defined immunopathological patterns of multiple sclerosis.

Design, Setting and Participants

This single-center cohort study recruited 69 patients nationwide between 2005 and 2016. All included patients had a diagnosis of early active inflammatory demyelination consistent with multiple sclerosis; were classified into patterns 1, 2, or 3 based on brain biopsy analysis; and underwent apheresis treatments. Patients who had concomitant severe disease, neuromyelitis optica, or acute disseminated encephalomyelitis were excluded.

Main Outcomes and Measures

The primary therapy outcome was a functionally relevant improvement of the relapse-related neurological deficit. Radiological and Expanded Disability Status Scale changes were secondary outcome parameters.

Results

The mean (SD) age of patients was 36.6 (13.3) years; 46 of the 69 participants (67%) were female. Overall, 16 patients (23%) exhibited pattern 1 lesions, 40 (58%) had pattern 2 lesions, and 13 (19%) had pattern 3 lesions. A functional therapy response was observed in 5 of the 16 patients with pattern 1 disease (31%) and 22 of the 40 patients with pattern 2 disease (55%), but none of the 13 patients with pattern 3 disease exhibited improvement (pattern 2 vs 3 P < .001). Radiological improvements were found in 4 (25%), 22 (56%), and 1 (11%) of patients with patterns 1, 2, and 3, respectively. The respective rates of response measured by changes in Expanded Disability Status Scale scores were 25%, 40%, and 0%. Brainstem involvement was a negative predictive factor for the functional therapy response (logarithmic odds ratio [logOR], -1.43; 95% CI, -3.21 to 0.17; P = .03), while immunoadsorption (as compared with plasma exchange) might be a positive predictive factor (logOR, 3.26; 95% CI, 0.75 to 8.13; P = .01).

Conclusions and Relevance

This cohort study provides evidence that the response to apheresis treatment is associated with immunopathological patterns. Patients with both patterns 1 and 2 improved clinically after apheresis treatment, but pattern 2 patients who showed signs of a humoral immune response benefited most. Apheresis appears unlikely to benefit patients with pattern 3 lesions.

Review: Recent advances in the understanding of the pathophysiology of neuromyelitis optica spectrum disorder

Neuromyelitis optica is an autoimmune inflammatory disorder of the central nervous system that preferentially targets the spinal cord and optic nerve. Following the discovery of circulating antibodies against the astrocytic aquaporin 4 (AQP4) water channel protein, recent studies have expanded our knowledge of the unique complexities of the pathogenesis of neuromyelitis optica and its relationship with the immune response. This review describes and summarizes the recent advances in our understanding of the molecular mechanisms underlying neuromyelitis optica disease pathology and examines their potential as therapeutic targets. Additionally, we update the most recent research by proposing major unanswered questions regarding how peripheral AQP4 antibodies are produced and their entry into the central nervous system, the causes of AQP4-IgG-seronegative disease, why peripheral AQP4-expressing organs are spared from damage, and the impact of this disease on pregnancy.

Efficacy of Therapeutic Plasma Exchange in Patients with Severe Refractory Anti-NMDA Receptor Encephalitis

The objective of the present study was to assess the efficacy of therapeutic plasma exchange (TPE) in patients with severe refractory anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis. Patients with severe anti-NMDA receptor encephalitis who showed no improvement after steroids and/or intravenous immunoglobulin treatment for at least 10 days were enrolled. All patients received immunotherapy and were divided into a TPE group and a non-TPE group according to treatment received. Each patient in the TPE group received at least 1 TPE course. NMDA receptor antibody titers in the cerebrospinal fluid (CSF) and plasma were evaluated within 1 week after the last TPE procedure. The clinical efficacy of treatment was evaluated after 1 month, 2 months, 3 months, 6 months, and 12 months. Forty patients were enrolled: 19 in the TPE group and 21 in the non-TPE group. Nineteen patients received TPE for a total of 118 procedures. NMDA receptor antibody titers in the CSF and/or plasma decreased or were negative after the last TPE procedure in 18 patients (94.7%). Compared with the non-TPE group, the TPE group exhibited greater clinical improvement after 1 month and 2 months following treatment (P < 0.05). After 3 months, 6 months, and 12 months, there were no significant differences in the outcomes between the TPE group and non-TPE group. The results suggest that TPE might rapidly improve the clinical manifestations in patients with severe refractory anti-NMDA receptor encephalitis, and we believe that TPE should be considered as a first-line treatment.

A case report of hepatitis B related optic neuritis treated with plasma exchange

INTRODUCTION

There are few studies focusing on Binocular hepatitis B related optic neuritis (HB-ON) and associated therapies are still limited. We present a case of HB-ON which has been cured with therapeutic plasma exchange (TPE).

PATIENT CONCERNS

The patient was diagnosed as acute hepatitis B in hepatology and got a rapid loss of binocular visual acuity (2/100 in the right eye and no light perception in the left eye) after the onset.

DIAGNOSIS

Hepatitis B related optic neuritis.

INTERVENTIONS

Methylprednisolone and therapeutic plasma exchange.

OUTCOMES

The treatment of high dose methylprednisolone was not curative. After 5 TPE sessions, the patient's best corrected visual acuity (BCVA) returned to 20/20 in the right eye and finger counting (FC)/40 cm in the left eye. One month later, the visual acuity increased to 5/100 in the left eye.

CONCLUSION

This is the first case in which we used TPE to cure HB-ON. Also, it can demonstrate the relationship between HB-ON and immunopathogenesis. The case may provide an effective method for the treatment of hormone invalid and disabled ON in clinical practice.

Predictive value of conventional MRI parameters in first spinal attacks of neuromyelitis optica spectrum disorder

Background:

While spinal cord (SC) attacks of neuromyelitis optica spectrum disorder (NMOSD) are often devastating, signs predictive of their poor clinical outcome have been elusive until now, except for the delay in initiating plasma exchange (PE).

Objective:

We studied the correlation between conventional non-standardized magnetic resonance imaging (MRI) parameters, PE treatment, and clinical data obtained at nadir and recovery.

Methods:

Retrospective study of first SC attacks of NMOSD.

Results:

Sixty-nine Afro-Caribbean NMOSD patients were included (aquaporin-4 (AQP4) antibodies positive in 65%). Median nadir and residual expanded disability status score (EDSS) were, respectively, 7.5 and 4.0. In bivariate analysis, all conventional MRI parameters were correlated with nadir and residual EDSS. In multivariate analysis, nadir EDSS correlated with lesion length ( p = 0.022) and edema ( p = 0.019), whereas residual EDSS correlated with T1w (T1-weighted) hypointense signal ( p = 0.003). Gadolinium enhancement was not associated with outcome.

Conclusion:

A specific pattern of lesions in conventional MRI data is differentially associated with nadir and residual EDSS. Lesions associated with poor prognosis should prompt highly efficient treatment.

The establishment of in-house neurology driven therapeutic plasma exchange infrastructure in a resource-limited public hospital in Malaysia: Adopting and integrating evidenced-based health care technology through time

There has been an increase in the use of therapeutic plasma exchange (TPE) in immune-mediated neurological disorders in recent years. However, accessibility and availability of TPE remains low and costly, especially for a country with limited healthcare funding like Malaysia. With expanding clinical indications in neurological disorders, and increasingly expensive conventional immunomodulatory treatment such as intravenous immunoglobulin and monoclonal antibodies, TPE remains an effective part of first or second-line treatment. In this article, we detailed the historical aspects of the use of TPE in neurological disorders in Malaysia over the last four decades and discussed the challenges behind the establishment of the first in-house neurology-driven TPE service in the country. Local TPE database from a national neurology centre in Kuala Lumpur over the past 20 years was analyzed. We observed a remarkable three folds increase in the use of TPE at our center over the past 10 years (total 131 TPE treatments) compared to a decade prior, with expanding clinical indications predominantly for central nervous system demyelinating disorders. Besides using membrane filtration method, centrifugal technique was adopted, providing new opportunities for other clinical beneficiaries such as a neurologist driven "in-house TPE unit". However, there were real world challenges, especially having to provide services with limited funding, human resources, and space. In addition, much has to be done to improve accessibility, availability, and sustainability of TPE services at our center and nationwide. Nevertheless, even with limited resources and support, it is possible with concerted efforts to work within the confines of these limitations to establish a safe, successful, and sustainable TPE service.

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.