Frequency of Aquaporin-4 Immunoglobulin G in Longitudinally Extensive Transverse Myelitis With Antiphospholipid Antibodies

Neurologic Manifestations of Rheumatologic Disorders

OBJECTIVE

This article provides an overview of the neurologic manifestations of sarcoidosis and select rheumatologic disorders. An approach to the assessment and differential diagnosis of characteristic clinical presentations, including meningitis and vasculitis, is also reviewed. A review of treatment options is included as well as discussion of distinct areas of overlap, including rheumatologic disease in the setting of neuromyelitis spectrum disorder and demyelinating disease in the setting of tumor necrosis factor-α inhibitors.

LATEST DEVELOPMENTS

An increased understanding of the immune mechanisms involved in sarcoidosis and rheumatologic diseases has resulted in a greater diversity of therapeutic options for their treatment. Evidence directing the treatment of the central nervous system (CNS) manifestations of these same diseases is lacking, with a paucity of controlled trials.

ESSENTIAL POINTS

It is important to have a basic knowledge of the common CNS manifestations of rheumatologic diseases and sarcoidosis so that they can be recognized when encountered. In the context of many systemic inflammatory diseases, including systemic lupus erythematosus, IgG4-related disease, and sarcoidosis, CNS disease may be a presenting feature or occur without systemic manifestations of the disease, making familiarity with these diseases even more important.

A comprehensive review of the advances in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare relapsing neuroinflammatory autoimmune astrocytopathy, with a predilection for the optic nerves and spinal cord. Most cases are characterised by aquaporin-4-antibody positivity and have a relapsing disease course, which is associated with accrual of disability. Although the prognosis in NMOSD has improved markedly over the past few years owing to advances in diagnosis and therapeutics, it remains a severe disease. In this article, we review the evolution of our understanding of NMOSD, its pathogenesis, clinical features, disease course, treatment options and associated symptoms. We also address the gaps in knowledge and areas for future research focus.

Non-demyelinating disorders mimicking and misdiagnosed as NMOSD: a literature review

BACKGROUND

Differentiating neuromyelitis optica spectrum disorder (NMOSD) from its mimics is crucial to avoid misdiagnosis, especially in the absence of aquaporin-4-IgG. While multiple sclerosis (MS) and myelin oligodendrocyte glycoprotein-IgG associated disease (MOGAD) represent major and well-defined differential diagnoses, non-demyelinating NMOSD mimics remain poorly characterized.

METHODS

We conducted a systematic review on PubMed/MEDLINE to identify reports of patients with non-demyelinating disorders that mimicked or were misdiagnosed as NMOSD. Three novel cases seen at the authors' institutions were also included. The characteristics of NMOSD mimics were analyzed and red flags associated with misdiagnosis identified.

RESULTS

A total of 68 patients were included; 35 (52%) were female. Median age at symptoms onset was 44 (range, 1-78) years. Fifty-six (82%) patients did not fulfil the 2015 NMOSD diagnostic criteria. The clinical syndromes misinterpreted for NMOSD were myelopathy (41%), myelopathy + optic neuropathy (41%), optic neuropathy (6%), or other (12%). Alternative etiologies included genetic/metabolic disorders, neoplasms, infections, vascular disorders, spondylosis, and other immune-mediated disorders. Common red flags associated with misdiagnosis were lack of cerebrospinal fluid (CSF) pleocytosis (57%), lack of response to immunotherapy (55%), progressive disease course (54%), and lack of magnetic resonance imaging gadolinium enhancement (31%). Aquaporin-4-IgG positivity was detected in five patients by enzyme-linked immunosorbent assay (n = 2), cell-based assay (n = 2: serum, 1; CSF, 1), and non-specified assay (n = 1).

CONCLUSIONS

The spectrum of NMOSD mimics is broad. Misdiagnosis frequently results from incorrect application of diagnostic criteria, in patients with multiple identifiable red flags. False aquaporin-4-IgG positivity, generally from nonspecific testing assays, may rarely contribute to misdiagnosis.

Myelitis features and outcomes in CNS demyelinating disorders: Comparison between multiple sclerosis, MOGAD, and AQP4-IgG-positive NMOSD

Inflammatory myelopathies can manifest with a combination of motor, sensory and autonomic dysfunction of variable severity. Depending on the underlying etiology, the episodes of myelitis can recur, often leading to irreversible spinal cord damage and major long-term disability. Three main demyelinating disorders of the central nervous system, namely multiple sclerosis (MS), aquaporin-4-IgG-positive neuromyelitis optica spectrum disorders (AQP4+NMOSD) and myelin oligodendrocyte glycoprotein-IgG associated disease (MOGAD), can induce spinal cord inflammation through different pathogenic mechanisms, resulting in a more or less profound disruption of spinal cord integrity. This ultimately translates into distinctive clinical-MRI features, as well as distinct patterns of disability accrual, with a step-wise worsening of neurological function in MOGAD and AQP4+NMOSD, and progressive disability accrual in MS. Early recognition of the specific etiologies of demyelinating myelitis and initiation of the appropriate treatment is crucial to improve outcome. In this review article we summarize and compare the clinical and imaging features of spinal cord involvement in these three demyelinating disorders, both during the acute phase and over time, and outline the current knowledge on the expected patterns of disability accrual and outcomes. We also discuss the potential implications of these observations for patient management and counseling.

Neuroimaging features in inflammatory myelopathies: A review

Spinal cord involvement can be observed in the course of immune-mediated disorders. Although multiple sclerosis (MS) represents the leading cause of inflammatory myelopathy, an increasing number of alternative etiologies must be now considered in the diagnostic work-up of patients presenting with myelitis. These include antibody-mediated disorders and cytotoxic T cell-mediated diseases targeting central nervous system (CNS) antigens, and systemic autoimmune conditions with secondary CNS involvement. Even though clinical features are helpful to orient the diagnostic suspicion (e.g., timing and severity of myelopathy symptoms), the differential diagnosis of inflammatory myelopathies is often challenging due to overlapping features. Moreover, noninflammatory etiologies can sometimes mimic an inflammatory process. In this setting, magnetic resonance imaging (MRI) is becoming a fundamental tool for the characterization of spinal cord damage, revealing a pictorial scenario which is wider than the clinical manifestations. The characterization of spinal cord lesions in terms of longitudinal extension, location on axial plane, involvement of the white matter and/or gray matter, and specific patterns of contrast enhancement, often allows a proper differentiation of these diseases. For instance, besides classical features, such as the presence of longitudinally extensive spinal cord lesions in patients with aquaporin-4-IgG positive neuromyelitis optica spectrum disorder (AQP4+NMOSD), novel radiological signs (e.g., H sign, trident sign) have been recently proposed and successfully applied for the differential diagnosis of inflammatory myelopathies. In this review article, we will discuss the radiological features of spinal cord involvement in autoimmune disorders such as MS, AQP4+NMOSD, myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), and other recently characterized immune-mediated diseases. The identification of imaging pitfalls and mimics that can lead to misdiagnosis will also be examined. Since spinal cord damage is a major cause of irreversible clinical disability, the recognition of these radiological aspects will help clinicians achieve a correct and prompt diagnosis, treat early with disease-specific treatment and improve patient outcomes.

Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD): A Review of Clinical and MRI Features, Diagnosis, and Management

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is the most recently defined inflammatory demyelinating disease of the central nervous system (CNS). Over the last decade, several studies have helped delineate the characteristic clinical-MRI phenotypes of the disease, allowing distinction from aquaporin-4 (AQP4)-IgG-positive neuromyelitis optica spectrum disorder (AQP4-IgG+NMOSD) and multiple sclerosis (MS). The clinical manifestations of MOGAD are heterogeneous, ranging from isolated optic neuritis or myelitis to multifocal CNS demyelination often in the form of acute disseminated encephalomyelitis (ADEM), or cortical encephalitis. A relapsing course is observed in approximately 50% of patients. Characteristic MRI features have been described that increase the diagnostic suspicion (e.g., perineural optic nerve enhancement, spinal cord H-sign, T2-lesion resolution over time) and help discriminate from MS and AQP4+NMOSD, despite some overlap. The detection of MOG-IgG in the serum (and sometimes CSF) confirms the diagnosis in patients with compatible clinical-MRI phenotypes, but false positive results are occasionally encountered, especially with indiscriminate testing of large unselected populations. The type of cell-based assay used to evaluate for MOG-IgG (fixed vs. live) and antibody end-titer (low vs. high) can influence the likelihood of MOGAD diagnosis. International consensus diagnostic criteria for MOGAD are currently being compiled and will assist in clinical diagnosis and be useful for enrolment in clinical trials. Although randomized controlled trials are lacking, MOGAD acute attacks appear to be very responsive to high dose steroids and plasma exchange may be considered in refractory cases. Attack-prevention treatments also lack class-I data and empiric maintenance treatment is generally reserved for relapsing cases or patients with severe residual disability after the presenting attack. A variety of empiric steroid-sparing immunosuppressants can be considered and may be efficacious based on retrospective or prospective observational studies but prospective randomized placebo-controlled trials are needed to better guide treatment. In summary, this article will review our rapidly evolving understanding of MOGAD diagnosis and management.

Neuropsychiatric Systemic Lupus Erythematosus in Older Adults: Diagnosis and Management

Systemic lupus erythematosus (SLE) is a multisystem chronic autoimmune disease with variable clinical manifestations. Neuropsychiatric systemic lupus erythematosus (NPSLE) includes the neurologic syndromes of the central, peripheral and autonomic nervous system and the psychiatric syndromes observed in patients with SLE. Neuropsychiatric systemic lupus erythematosus events may present as an initial manifestation of SLE or may be diagnosed later in the course of the disease. Older adults with NPLSE include those who are ageing with known SLE and those with late-onset SLE. The diagnosis of NPSLE across the lifespan continues to be hampered by the lack of sensitive and specific laboratory and imaging biomarkers. In this review, we discuss the particular complexity of NPSLE diagnosis and management in older adults. We first discuss the epidemiology of late-onset NPSLE, then review principles of diagnosis of NPSLE, highlighting issues that are pertinent to older adults and that make diagnosis and attribution more challenging, such as atypical disease presentation, higher medical comorbidity, and differences in neuroimaging and autoantibody investigations. We also discuss clinical issues that are of particular relevance to older adults that have a high degree of overlap with SLE, including drug-induced lupus, cerebrovascular disease and neurocognitive disorders. Finally, we review the management of NPSLE, mainly moderate to high- dose glucocorticoids and immunosuppressants, again highlighting considerations for older adults, such as increased medication (especially glucocorticoids) adverse effects, ageing-related pharmacokinetic changes that can affect SLE medication management, medication dosing and attention to medical comorbidities affecting brain health.

Multi-Level Analyses of Genome-Wide Association Study to Reveal Significant Risk Genes and Pathways in Neuromyelitis Optica Spectrum Disorder

Background

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease of the central nervous system and it is understandable that environmental and genetic factors underlie the etiology of NMOSD. However, the susceptibility genes and associated pathways of NMOSD patients who are AQP4-Ab positive and negative have not been elucidated.

Methods

Secondary analysis from a NMOSD Genome-wide association study (GWAS) dataset originally published in 2018 (215 NMOSD cases and 1244 controls) was conducted to identify potential susceptibility genes and associated pathways in AQP4-positive and negative NMOSD patients, respectively (132 AQP4-positive and 83 AQP4-negative).

Results

In AQP4-positive NMOSD cases, five shared risk genes were obtained at chromosome 6 in AQP4-positive NMOSD cases by using more stringent p-Values in both methods (p < 0.05/16,532), comprising CFB, EHMT2, HLA-DQA1, MSH5, and SLC44A4. Fifty potential susceptibility gene sets were determined and 12 significant KEGG pathways were identified. Sixty-seven biological process pathways, 32 cellular-component pathways, and 29 molecular-function pathways with a p-Value of <0.05 were obtained from the GO annotations of the 128 pathways identified. In the AQP4 negative NMOSD group, no significant genes were obtained by using more stringent p-Values in both methods (p < 0.05/16,485). The 22 potential susceptibility gene sets were determined. There were no shared potential susceptibility genes between the AQP4-positive and negative groups, furthermore, four significant KEGG pathways were also identified. Of the GO annotations of the 165 pathways identified, 99 biological process pathways, 37 cellular-component pathways, and 29 molecular-function pathways with a p-Value of <0.05 were obtained.

Conclusion

The potential molecular mechanism underlying NMOSD may be related to proteins encoded by these novel genes in complements, antigen presentation, and immune regulation. The new results may represent an improved comprehension of the genetic and molecular mechanisms underlying NMOSD.

Antibody-Mediated Autoimmune Diseases of the CNS: Challenges and Approaches to Diagnosis and Management

Antibody-mediated disorders of the central nervous system (CNS) are increasingly recognized as neurologic disorders that can be severe and even life-threatening but with the potential for reversibility with appropriate treatment. The expanding spectrum of newly identified autoantibodies targeting glial or neuronal (neural) antigens and associated clinical syndromes (ranging from autoimmune encephalitis to CNS demyelination) has increased diagnostic precision, and allowed critical reinterpretation of non-specific neurological syndromes historically associated with systemic disorders (e.g., Hashimoto encephalopathy). The intracellular vs. cell-surface or synaptic location of the different neural autoantibody targets often helps to predict the clinical characteristics, potential cancer association, and treatment response of the associated syndromes. In particular, autoantibodies targeting intracellular antigens (traditionally termed onconeural autoantibodies) are often associated with cancers, rarely respond well to immunosuppression and have a poor outcome, although exceptions exist. Detection of neural autoantibodies with accurate laboratory assays in patients with compatible clinical-MRI phenotypes allows a definite diagnosis of antibody-mediated CNS disorders, with important therapeutic and prognostic implications. Antibody-mediated CNS disorders are rare, and reliable autoantibody identification is highly dependent on the technique used for detection and pre-test probability. As a consequence, indiscriminate neural autoantibody testing among patients with more common neurologic disorders (e.g., epilepsy, dementia) will necessarily increase the risk of false positivity, so that recognition of high-risk clinical-MRI phenotypes is crucial. A number of emerging clinical settings have recently been recognized to favor development of CNS autoimmunity. These include antibody-mediated CNS disorders following herpes simplex virus encephalitis or occurring in a post-transplant setting, and neurological autoimmunity triggered by TNFα inhibitors or immune checkpoint inhibitors for cancer treatment. Awareness of the range of clinical and radiological manifestations associated with different neural autoantibodies, and the specific settings where autoimmune CNS disorders may occur is crucial to allow rapid diagnosis and early initiation of treatment.

Spine MRI: A Review of Commonly Encountered Emergent Conditions

Over the last 2 decades, the proliferation of magnetic resonance imaging (MRI) availability and continuous improvements in acquisition speeds have led to significantly increased MRI utilization across the health care system, and MRI studies are increasingly ordered in the emergent setting. Depending on the clinical presentation, MRI can yield vital diagnostic information not detectable with other imaging modalities. The aim of this text is to report on the up-to-date indications for MRI of the spine in the ED, and review the various MRI appearances of commonly encountered acute spine pathology, including traumatic injuries, acute non traumatic myelopathy, infection, neoplasia, degenerative disc disease, and postoperative complications. Imaging review will focus on the aspects of the disease process that are not readily resolved with other modalities.

A case of longitudinally extensive transverse myelitis in an 80-year-old patient with systemic lupus erythematous and anti-aquaporin 4 antibodies

BACKGROUND

Systemic Lupus Erythematous is a systemic autoimmune disease with multiorgan inflammation. Clinical manifestations are variable and may involve the Central Nervous System. Acute transverse myelitis is a rare complication. Recent studies have shown an association between SLE, transverse myelitis and presence of anti-aquaporin 4 antibodies.

CASE PRESENTATION

We describe the case of an 80-year-old woman with a subacute onset of right hemiplegia followed by left-sided ataxia. Cervical MRI revealed longitudinally extensive transverse myelitis. Blood examinations showed positivity for anti-nuclear antibodies, anti-double-stranded DNA antibodies, anti-phospholipid antibodies and anti-aquaporin 4 antibodies.

CONCLUSIONS

Anti-aquaporin 4 antibody testing is of paramount importance in order to reach a correct diagnosis and to treat patients with the best therapeutic approach.

Myelitis and Other Autoimmune Myelopathies

PURPOSE OF REVIEW

This article provides an update on the clinical diagnosis and management of immune-mediated myelopathies, including the relevance of imaging, ancillary testing with an emphasis on autoantibody biomarkers, recognition of myelitis mimics, and therapeutic approach.

RECENT FINDINGS

The imaging characterization of immune-mediated myelopathies and the discovery of neural autoantibodies have been crucial in improving our ability to accurately diagnose myelitis. The identification of autoantibodies directed against specific central nervous system targets has led to major improvements in our understanding of the mechanisms underlying inflammation in myelitis. It has also allowed distinction of these myelopathy etiologies from noninflammatory etiologies of myelopathy and from multiple sclerosis and provided insight into their risk of recurrence, treatment response, and long-term clinical outcomes. Prompt recognition and appropriate testing in the setting of acute and subacute myelopathies is critical as timely administration of immunotherapy can help improve symptoms and prevent permanent neurologic disability. A patient should not be classified as having "idiopathic transverse myelitis" without a comprehensive evaluation for a more specific etiology. Achieving the correct diagnosis and learning to recognize noninflammatory myelitis mimics is crucial as they have therapeutic and prognostic implications.

SUMMARY

Identifying the clinical and radiographic features of immune-mediated myelitis and recognizing mimics and pitfalls will help clinicians treat confirmed autoimmune myelitis appropriately.

Neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein IgG associated disorder: A comprehensive neuro-ophthalmic review

Neuromyelitis optica spectrum disorder (NMOSD) is an antibody-mediated inflammatory disease of the central nervous system that involves the optic nerves, spinal cord, and often other specific brain regions such as area postrema of the medulla. NMOSD was formerly classified as a variant of multiple sclerosis (MS), given the similar symptomatology and relapsing course but is now considered to have distinct clinical, paraclinical, immunological and prognostic features. The discovery of aquaporin 4 (AQP4) immunoglobulin G (IgG) has improved the ability to diagnose NMOSD. AQP4-IgG targets the astrocytic AQP4 water channel leading to complement activation and increased blood-brain barrier permeability. Accurate and early diagnosis is crucial as timely treatment may result in mitigation of long-term disability. Myelin oligodendrocyte glycoprotein (MOG)-IgG associated disorder (MOGAD) is a distinct nosologic entity, which has been more recently described. Its clinical spectrum partly overlaps that of seronegative NMOSD and MS. Although it is considered to have fewer relapses and better prognosis than NMOSD, the clinical course and outcome of MOGAD has not been fully characterized.

Complete spinal cord involvement from neuromyelitis optica spectrum disorder in an adult female with anti-synthetase syndrome

Anti-synthetase syndrome (ASS) is a rare autoimmune disorder characterized by the presence of antibodies against aminoacyl-transfer RNA synthetase commonly associated inflammatory myopathy. In this case report, we describe an adult female with NMOSD concurrent with ASS in which the lesion involved the entire length of the spinal cord. Since B-cell mediated molecular pathway is involved in the pathogenesis of NMOSD and ASS, we suggest that the therapeutically targeted killing of B-cells, such as Rituximab, is effective.

[Actual issues of serum aquaporin-4 autoantibodies evaluation in the diagnostics of neuromyelitis optica spectrum disorders]

OBJECTIVE

To analyze the usage and timeliness of aquaporin-4 antibodies (AQP4-IgG) serology test in the diagnostics of neuromyelitis optica spectrum disorders (NMOSD) in routine clinical practice.

MATERIAL AND METHODS

27 patients with NMOSD were included in the study. All patients had a positive serum test for AQP4-IgG. A retrospective study of neurological manisfestations of attacks, timing and results of serology for AQP4-IgG was performed. The results were analyzed taking into account two types of attacks identified: a) HS (with highly specific manifestations for NMOSD), which are considered as indications for conducting the AQP4-IgG test and b) NS (with non-specific manifestations for NMOSD).

RESULTS AND CONCLUSION

A comparison of the time from HS attack to the AQP4-IgG test administration (T1, years), from HS attack to NMOSD diagnosis (T2, years) was undertaken as well as the number of attacks during these periods (N1, N2) were counted in three groups of patients. Group 1 - with the first HS attack before or in 2008 (n=6), group 2 - from 2009 to 2013 (n=12), group 3 - from 2014 to 2018 (n=9) accordingly. A statistically significant decrease in T1, T2, N1, N2 was found in successive time intervals of 5 years (p<0.05). In 8 of 27 (28.6%) patients the first attack of NMOSD was presented with non-specific symptoms (NS attack). In 7 patients (77.8%) of 9 misdiagnosed as multiple sclerosis (MS) an increase in attack frequency was found while on disease modifying therapies (DMTs) and increase in attack severity was found in 8 (88.9%). In all 9 cases the diagnosis was revised to NMOSD after AQP4-IgG test was performed with positive result. The time interval from disease course worsening while on DMTs until the test was 7 [4; 37] months, and the number of relapses - 2 [0; 3]. In 4 of 27 patients with suspected NMOSD, the repeated AQP4-IgG test only was positive for increased antibodies titer. The time interval between first test negative and retest administered was 20 [6.1; 47.8] months. In 3 of 4 patients (75%) one or more attacks occurred during this time period. In 4 patients the presence of AQP4-IgG in the first analysis was not followed by the diagnosis of NMOSD. In recent years, apropos AQP4-IgG test administration improved, but the problem remains with the timeliness for retest with first result negative. It is advisable to expand the indications for its use. The timeliness for serum AQP4-IgG retest in cases of unexplained deterioration in the course of proposed MS on DMTs and the lack of awareness of the test diagnostic value are still relevant.

[Transverse myelitis syndrom as a result of neuromyelitis optica spectrum disorders, systemic lupus erythematosus and myasthenia gravis combination]

Neuromyelitis optica spectrum disorders (NMOSD) - autoimmune condition characterized by an inflammatory lesions mainly of the spinal cord with the development of longitudinally extensive transverse myelitis (LETM) and/or involvement of the optic nerve with the development of usually bilateral optical neuritis (ON). In recent years, there has been increased awareness that NMOSD can be combined with other autoimmune diseases, including myasthenia gravis (MG), systemic lupus erythematosus (SLE) et al. The simultaneous presence of several autoimmune diseases in one patient can adversely affect the course of each of the diseases, causing the so-called mutual burden or «overlap syndrome». In this article, we describe our own clinical observation of a 51-year-old woman of European origin who developed acute relapsing TM seropositive for AQP4-IgG, by 23 years after the diagnosis of generalized MG seropositive for antibodies to acetylcholine receptors (AChR-Ab) and the occurrence of SLE, criterially confirmed, several months after the initial TM attack. During the fourth TM attack, partial positive dynamics was achieved only against the background of the combined use of intravenous methylprednisolone (pulse therapy), high-volume plasma exchange, rituximab and cyclophosphamide. The NMOSD is a rare disease leading to severe disability. In patients with MG, when symptoms of damage to the central nervous system appear, an analysis should be performed for AQP4-IgG and possibly for antibodies to myelin glycoprotein of oligodendrocytes (MOG-Ab), as well as markers characteristic of systemic connective tissue diseases (SCTD). In patients with STDD, when symptoms of involvement nervous systemappear, testing for AQP4-IgG (and, if necessary, for MOG-Ab) should be performed to exclude NMOSD, as well as AChR-Ab (and, if necessary, antibodies against muscle specific kinase (MuSK-Ab)) to exclude MG.

Coexisting systemic and organ-specific autoimmunity in MOG-IgG1-associated disorders versus AQP4-IgG+ NMOSD

Aquaporin-4 (AQP4) neuromyelitis optica spectrum disorder (NMOSD) has been demonstrated to be associated with non-organ and organ-specific autoantibodies (antinuclear antibody, extractable nuclear antibody, double-stranded DNA, muscle acetylcholine receptor antibody) and systemic autoimmune diseases. In this study, we evaluated whether a similar association with non-organ and organ-specifc autoantibodies occurs in patients with MOG-IgG1-associated disorders. We determined that MOG-IgG1 was not strongly associated with these organ and non-organ-specific autoantibodies. Systemic lupus erythematous (SLE) was significantly associated with AQP4-IgG+ NMOSD and not with MOGAD (p = 0.037). These findings suggest differences in co-existing systemic and organ-specific autoimmunity between MOGAD and AQP4-IgG+ NMOSD.

Treatment of neuromyelitis optica spectrum disorders

PURPOSE OF REVIEW

This review discusses concepts for diagnosing neuromyelitis optica spectrum disorders (NMOSD), distinguishing NMOSD from other inflammatory diseases of the central nervous system, and highlights recent and forthcoming data on acute and maintenance therapy of NMOSD.

RECENT FINDINGS

The neurologic manifestations of NMOSD are heterogenous, extending beyond classic presentations of optic neuritis and longitudinally extensive transverse myelitis. NMOSD may be comorbid with rheumatologic diseases, such as systemic lupus erythematosus, but is recognized as a distinct entity. Recent studies of acute treatment of NMOSD support early use of plasmapheresis. Relapse prevention is essential, as relapses can be disabling and patients may have only partial recovery. Current practice generally recommends at least 5 years of maintenance treatment. Recent randomized data demonstrates superiority of rituximab over azathioprine. Phase 3 trials have recently been completed or are underway studying novel therapies employing B-cell depletion, complement inhibition, and cell-based mechanisms (among other mechanisms) for maintenance therapy of NMOSD.

SUMMARY

NMOSD is a heterogeneous but well-defined clinical entity, distinct from other neurologic and systemic inflammatory diseases, and treatment is poised for expansion.

Neuromyelitis Optica Spectrum Disorder and Other Non-Multiple Sclerosis Central Nervous System Inflammatory Diseases

PURPOSE OF REVIEW

This article reviews the clinical features, diagnostic approach, treatment, and prognosis of central nervous system inflammatory diseases that mimic multiple sclerosis (MS), including those defined by recently discovered autoantibody biomarkers.

RECENT FINDINGS

The discovery of autoantibody biomarkers of inflammatory demyelinating diseases of the central nervous system (aquaporin-4 IgG and myelin oligodendrocyte glycoprotein IgG) and the recognition that, despite some overlap, their clinical phenotypes are distinct from MS have revolutionized this field of neurology. These autoantibody biomarkers assist in diagnosis and have improved our understanding of the underlying disease pathogenesis. This has allowed targeted treatments to be translated into clinical trials, three of which are now under way in aquaporin-4 IgG-seropositive neuromyelitis optica (NMO) spectrum disorder.

SUMMARY

Knowledge of the clinical attributes, MRI findings, CSF parameters, and accompanying autoantibody biomarkers can help neurologists distinguish MS from its inflammatory mimics. These antibody biomarkers provide critical diagnostic and prognostic information and guide treatment decisions. Better recognition of the clinical, radiologic, and laboratory features of other inflammatory MS mimics that lack autoantibody biomarkers has allowed us to diagnose these disorders faster and initiate disease-specific treatments more expeditiously.

Systemic lupus erythematosus with the development of neuromyelitis optica (Devic's syndrome) is a rare combination of autoimmune diseases

Neuromyelitis optica ((NMO), Devic's syndrome) is an immune-mediated inflammatory demyelinating disease characterized by transverse myelitis and optic neuritis. Determination of the level of antibodies to aquaporin 4 (NMO-IgG) is presently one of the key methods for the diagnosis and assessment of the activity of ONM, which allows this disease to be differentiated from multiple sclerosis and other demyelinating CNS lesions. ONM can occur not only as an independent disease, but also as a syndrome in different systemic diseases, such as: systemic lupus erythematosus (SLE), antineutrophilic cytoplasmic antibody-associated vasculitides, Sjögren's disease, etc. (up to 50–70%). In such situations, the clinician is always confronted with a question as whether the patient can have two rare autoimmune diseases or develop ONM as a systemic manifestation of rheumatic disease.

The paper describes a clinical case of a young female patient with SLE concurrent with a CNS lesion, the manifestations of which corresponded to ONM. The patient had focal changes in the substance of the brain and spinal cord, as evidenced by magnetic resonance imaging, as well as high NMO-IgG titers. The development of ONM worsens SLE prognosis and requires active immunosuppressive therapy. The patient received three plasmapheresis sessions, ultrahigh-dose glucocorticoid and cyclophosphamide therapy, followed by replacement with azathioprine, causing a stable clinical and laboratory disease remission to be achieved.

Neuromyelitis optica spectrum disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an uncommon antibody-mediated disease of the central nervous system. Long segments of spinal cord inflammation (myelitis), severe optic neuritis, and/or bouts of intractable vomiting and hiccoughs (area postrema syndrome) are classic presentations of the disease and may alert the clinician to the diagnosis. 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. Approximately 75% of patients have antibodies against aquaporin-4, a water channel expressed on astrocytes. Relapses are treated aggressively to prevent residual disability with high-dose steroids and often plasma exchange. Relapse prevention is crucial and achieved with long-term immunosuppression. In this article we review the pathogenesis, clinical features, diagnosis and management of NMOSD.

Magnetic resonance imaging in immune-mediated myelopathies

Immune-mediated myelopathies are a heterogeneous group of inflammatory spinal cord disorders including autoimmune disorders with known antibodies, e.g. aquaporin-4 IgG channelopathy or anti-myelin oligodendrocyte glycoprotein-associated myelitis, myelopathies in the context of multiple sclerosis and systemic autoimmune disorders with myelopathy, as well as post-infectious and paraneoplastic myelopathies. Although magnetic resonance imaging of the spinal cord is still challenging due to the small dimension of the cord cross-section and frequent movement and susceptibility artifacts, recent methodological advances have led to improved diagnostic evaluation and characterization of immune-mediated myelopathies. Topography, length and width of the lesion, gadolinium enhancement pattern, and changes in morphology over time help in narrowing the broad differential diagnosis. In this review, we give an overview of recent advances in magnetic resonance imaging of immune-mediated myelopathies and its role in the differential diagnosis and monitoring of this heterogeneous group of disorders.

Neurological Disease in Lupus: Toward a Personalized Medicine Approach

The brain and nervous system are important targets for immune-mediated damage in systemic lupus erythematosus (SLE), resulting in a complex spectrum of neurological syndromes. Defining nervous system disease in lupus poses significant challenges. Among the difficulties to be addressed are a diversity of clinical manifestations and a lack of understanding of their mechanistic basis. However, despite these challenges, progress has been made in the identification of pathways which contribute to neurological disease in SLE. Understanding the molecular pathogenesis of neurological disease in lupus will inform both classification and approaches to clinical trials.