Seroprevalence and specificity of NMO-IgG (anti-aquaporin 4 antibodies) in patients with neuropsychiatric systemic lupus erythematosus

Neuropsychiatric Systemic Lupus Erythematosus: Molecules Involved in Its Imunopathogenesis, Clinical Features, and Treatment

Systemic lupus erythematosus (SLE) is an idiopathic chronic autoimmune disease that can affect any organ in the body, including the neurological system. Multiple factors, such as environmental (infections), genetic (many HLA alleles including DR2 and DR3, and genes including C4), and immunological influences on self-antigens, such as nuclear antigens, lead to the formation of multiple autoantibodies that cause deleterious damage to bodily tissues and organs. The production of autoantibodies, such as anti-dsDNA, anti-SS(A), anti-SS(B), anti-Smith, and anti-neuronal DNA are characteristic features of this disease. This autoimmune disease results from a failure of the mechanisms responsible for maintaining self-tolerance in T cells, B cells, or both. Immune complexes, circulating antibodies, cytokines, and autoreactive T lymphocytes are responsible for tissue injury in this autoimmune disease. The diagnosis of SLE is a rheumatological challenge despite the availability of clinical criteria. NPSLE was previously referred to as lupus cerebritis or lupus sclerosis. However, these terms are no longer recommended because there is no definitive pathological cause for the neuropsychiatric manifestations of SLE. Currently, the treatment options are primarily based on symptomatic presentations. These include the use of antipsychotics, antidepressants, and anxiolytic medications for the treatment of psychiatric and mood disorders. Antiepileptic drugs to treat seizures, and immunosuppressants (e.g., corticosteroids, azathioprine, and mycophenolate mofetil), are directed against inflammatory responses along with non-pharmacological interventions.

Neuro-psychiatric manifestations in patients with systemic lupus erythematosus: A systematic review and results from the Swiss lupus cohort study

Objectives

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease associated with neuro-psychiatric (NP) manifestations. Frequency and patterns of neuro-psychiatric systemic lupus erythematosus (NPSLE) vary substantially between patients. We conducted a systematic review (SR) of the literature and examined prevalence and characteristics of NPSLE in the Swiss SLE cohort study (SSCS).

Methods

The SR search was performed between January 1999 and January 2020. We included prospective/cross-sectional studies focusing on NPSLE. We secured study characteristics, cohort compositions and frequencies of NP manifestations, assessed heterogeneity across reports and investigated sources of variation using meta-regression models. Regarding the SSCS, we reviewed all patients included and classified NP manifestations.

Results

The SR searches identified 530 studies. We included 22 studies in our meta-analysis, the mean frequency of NPSLE ranged from 10.6% to 96.4%. The frequency of NPSLE in the SSCS was 28.1%. Severe events including cerebrovascular insults, seizures and psychosis appeared in 7.1%, 5.3% and 6.5% respectively. There was a linear relationship between duration of SLE and cumulative incidence of NPSLE.

Conclusions

The spectrum of NPSLE is very broad. The diagnostic work-up and rates of reported manifestations varied substantially across studies. We call for concerted efforts and consensus regarding definitions of NPSLE that will facilitate accurate diagnosis and attribution to SLE, particularly with a view to timely intervention and patient outcomes.

Cognitive Impairment in SLE: Mechanisms and Therapeutic Approaches

A wide range of patients with systemic lupus erythematosus (SLE) suffer from cognitive dysfunction (CD) which severely impacts their quality of life. However, CD remains underdiagnosed and poorly understood. Here, we discuss current findings in patients and in animal models. Strong evidence suggests that CD pathogenesis involves known mechanisms of tissue injury in SLE. These mechanisms recruit brain resident cells, in particular microglia, into the pathological process. While systemic immune activation is critical to central nervous system injury, the current focus of therapy is the microglial cell and not the systemic immune perturbation. Further studies are critical to examine additional potential therapeutic targets and more specific treatments based on the cause and progress of the disease.

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.

Neuromyelitis optica spectrum standstill in rheumatic systemic autoimmune diseases

Background

Neuromyelitis optica spectrum disorders (NMOSD) are considered as an autoantibody-mediated disorder that targets aquaporin-4 (AQP4); other autoantibodies could be detected in such spectrum of diseases, including anti-nuclear antibody and antibodies to extractable nuclear antigens. Systemic autoimmune diseases such as systemic lupus erythematosus (SLE), Sjogren’s syndrome (SS), and other autoimmune diseases can overlap with NMOSD. We aimed in this review to address the current evidence describing the relation of NMOSD to systemic autoimmunity diseases, its controversy of being co-association or the same etiology, and its practical implications.

Main body

The current review was done using a search for related articles or case reports on PubMed until 2019. The keywords included neuromyelitis optica spectrum disorders in combination with autoimmune disease nomenclature. We described the literature background of this controversy, to summarize the evidence of NMOSD relationship to systemic autoimmune diseases.

Conclusion

NMOSD associated with systemic autoimmune diseases is more common in SLE and Sjogren’s syndrome rather than other autoimmune diseases, frequently affects females more than males; AQP4 antibodies should be tested for all NMOSD like manifestations associated with an autoimmune disorder; however, the clinical diagnosis of NMOSD regardless of the cord lesion length and the presence of positive AQP4 antibody can occur in systemic autoimmune diseases.

The immunologic etiology of psychiatric manifestations in systemic lupus erythematosus: A narrative review on the role of the blood brain barrier, antibodies, cytokines and chemokines

INTRODUCTION

The aim of this narrative review is to provide an overview of the literature on the possible immunologic pathophysiology of psychiatric manifestations of neuropsychiatric systemic lupus erythematosus (NPSLE).

METHODS

A systematic search on PubMed was conducted. English studies with full text availability that investigated the correlation between blood-brain barrier (BBB) dysfunction, intrathecal synthesis of antibodies, antibodies, cytokines, chemokines, metalloproteinases, complement and psychiatric NPSLE manifestations in adults were included.

RESULTS

Both transient BBB-dysfunction with consequent access of antibodies to the cerebrospinal fluid (CSF) and intrathecal synthesis of antibodies could occur in psychiatric NPSLE. Anti-phospholipid antibodies, anti-NMDA antibodies and anti-ribosomal protein p antibodies seem to mediate concentration dependent neuronal dysfunction. Interferon-α may induce microglial engulfment of neurons, direct neuronal damage and production of cytokines and chemokines in psychiatric NPSLE. Several cytokines, chemokines and matrix metalloproteinase-9 may contribute to the pathophysiology of psychiatric NPSLE by attracting and activating Th1-cells and B-cells.

DISCUSSION

This potential pathophysiology may help understand NPSLE and may have implications for the diagnostic management and therapy of psychiatric NPSLE. However, the presented pathophysiological model is based on correlations between potential immunologic etiologies and psychiatric NPSLE that remain questionable. More research on this topic is necessary to further elucidate the pathophysiology of NPSLE.

Clinical features of transverse myelitis associated with systemic lupus erythematosus

Objective

This study aimed to identify the clinical characteristics and prognostic factors of systemic lupus erythematosus with transverse myelitis (SLE-TM) in a relatively large patient series.

Methods

This retrospective study considered 45 SLE-TM individuals treated as inpatients and outpatients at Peking Union Medical College Hospital between 1993 and 2018. SLE-TM patients were compared with 180 controls, and SLE-TM patients with neuromyelitis optica spectrum disorder (NMOSD) were compared to those without NMOSD.

Results

Compared to controls, the SLE-TM group frequently had a fever and had a significantly higher positive rate of anticardiolipin and lupus anticoagulant. Among the 45 patients, 22 met the NMOSD criteria. Compared to non-NMOSD patients, NMOSD patients had a lower incidence of rash ( p = 0.023), serositis ( p = 0.042) and renal disorder ( p = 0.073); a lower prevalence of decreased complement ( p = 0.083); and lower rates of positive anti-dsDNA ( p = 0.074) and anti-Sm ( p = 0.042). Among 22 SLE-TM patients with NMOSD, 18 underwent aquaporin 4 antibody testing, with 11 showing positive results. Out of the 45 patients, 39 were given methylprednisolone pulse treatment. After treatment, 32 patients had lower-limb muscle strength recovery (recovered group), whereas 13 had no change and persistent severe neurological deficits (non-recovered group). Compared to the recovered group, the non-recovered group were younger ( p = 0.002), had a higher likelihood of having a fever ( p = 0.020), initial severe myelitis ( p < 0.001), long spinal segment involvement ( p = 0.017) and higher C-reactive protein levels ( p = 0.020). Methylprednisolone pulse given within two weeks of onset was more frequent in the recovered group than in the non-recovered group ( p = 0.082).

Conclusions

Disease characteristics differed between SLE-TM patients with and without NMOSD. SLE and NMOSD tended to be co-morbidities. Initial severe neurological impairment, extensive spinal cord lesions, hyper-inflammation and delayed steroid impulse treatment could be predictors of poor outcome for SLE-TM.

Tumefactive Demyelination Associated with Bilateral Optic Neuritis in Neuromyelitis Optica Spectrum Disorders

Tumefactive demyelination is an uncommon neurological disorder mimicking tumors. It is one of the rare varieties of demyelinating disorders, often causing diagnostic dilemma among neuroscientists. The literature tells us about approaching these patients added by peculiar neuroimaging findings. Neuromyelitis optica is an immune mediated inflammatory clinical disorder, typically involving optic nerves bilaterally and longitudinally extensive transverse myelitis. With the revelation of aquaporin four channels, its distribution in the brain and related antibody, the concept of neuromyelitis optica spectra disorders has been evolved. In this case report, our intention is to present a young female who presented with bilateral vision loss with tumor-like mass lesion in cerebral cortex. Such an association of bilateral optic neuropathy involving chiasmatic region, suggestive of neuromyelitis optica spectrum disorder (NMOSD) with tumefactive demyelination is rarely reported in the literature.

Devic's index case: A critical reappraisal - AQP4-IgG-mediated neuromyelitis optica spectrum disorder, or rather MOG encephalomyelitis?

In 1894, Eugène Devic (1858-1930) and his doctoral student Fernand Gault (1873-1936) reported on a patient with optic neuritis (ON) and myelitis and proposed the name "neuro-myélite optique" for this syndrome. Subsequently, Devic became the eponym of neuromyelitis optica (NMO), which was then referred to as "Devic's syndrome", "Devic's disease" or "Morbus Devic". Thereby, the case became a historical index case of NMO. For many decades little attention was paid to NMO, which most authors considered a clinical variant of multiple sclerosis. However, the discovery of pathogenic antibodies to aquaporin-4 at the beginning of the 21st century revived interest in the syndrome, and AQP4-IgG-positive NMO spectrum disorders (NMOSD) are now studied as prototypical autoimmune diseases. More recently, antibodies to full-length myelin oligodendrocyte glycoprotein (MOG) have been detected in patients with ON as well as in patients with myelitis, some of whom exhibit a clinical phenotype very similar to that described by Devic. This raises the question of whether Devic's patient might have suffered from MOG encephalomyelitis rather than classic NMOSD. In this article, we summarise and discuss the available evidence for and against that hypothesis. We also discuss differential diagnoses and the question whether Devic's patient, who worked as a hatter and had initially been admitted for nervous hyperexcitability and tremor, might have suffered from co-existing erethism ('mad hatter disease'), which is caused by chronic occupational exposure to mercury.

Autoimmune diseases associated with Neuromyelitis Optica Spectrum Disorders: A literature review

INTRODUCTION

Neuromyelitis Optica (NMO) is an autoimmune inflammatory demyelinating disease of the central nervous system (CNS) which predominantly involves optic nerves and spinal cord. Since the introduction of Neuromyelitis Optica Spectrum Disorders (NMOSD) as a separate entity, there have been many reports on its association with other disorders including systemic and organ-specific autoimmune diseases. Here, we reviewed other immune-mediated diseases associated with NMOSD and tried to categorize them.

METHODS

The present review was conducted using the PUBMED database based on papers from 1976 (i.e., since the first NMO comorbidity with SLE was reported) to 2017. We included all articles published in English. The keywords utilized included Neuromyelitis optica, Neuromyelitis Optica Spectrum Disorders, Devic's disease, in combination with comorbidity or comorbidities.

RESULTS

Diseases with immune-based pathogenesis are the most frequently reported co-morbidities associated with NMOSD, most of which are antibody-mediated diseases. According to literature, Sjogren's Syndrome (SS) and Systemic Lupus Erythematosus (SLE) are the most frequently reported diseases associated with NMOSD among systemic autoimmune diseases. Further, myasthenia gravis in neurological and autoimmune thyroid diseases in non-neurological organ-specific autoimmune diseases are the most reported comorbidities associated with NMOSD in the literature.

CONCLUSIONS

NMOSD may be associated with a variety of different types of autoimmune diseases. Therefore, systemic or laboratory signs which are not typical for NMOSD should be properly investigated to exclude other associated comorbidities. These comorbidities may affect the treatment strategy and may improve the patients' care and management.

The role of ophthalmic imaging in central nervous system degeneration in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune connective tissue disorder that can involve any organ system. Central nervous system involvement can be a severe life threatening complication, ultimately resulting in severe neurodegenerative changes. Magnetic resonance imaging suggests that neurodegeneration, which may have deleterious effects on brain function, may occur early in SLE and experimental models suggest that neuroprotection may be feasible and beneficial. The retina is an extension of the brain. Recent ophthalmic imaging technologies are capable of identifying early changes in retinal and choroidal morphology and circulation that may reflect CNS degeneration. However, their utility in monitoring CNS involvement in SLE has been poorly studied as these have only been performed in small cohorts, in a cross-sectional design, non-quantitatively and without correlation to disease activity. The authors aim to review the current understanding of neurodegeneration associated with SLE, with particular focus on the visual pathway. We describe the neuropathology of the visual system in SLE and the evidence for retinal and choroidal neurodegenerative and microvascular changes using optical coherence tomography technology. We aim to describe the potential role of optical imaging modalities in NPSLE diagnosis and their likely impact on the study of neuronal function.

Aquaporin-4-autoimmunity in patients with systemic lupus erythematosus: A predominantly population-based study

BACKGROUND

Serum immunoglobulin G targeting the astrocyte water channel aquaporin-4 (AQP4) in the central nervous system (CNS) is a biomarker for neuromyelitis optica spectrum disease (NMOSD). Co-existence of NMOSD with systemic lupus erythematosus (SLE) putatively suggests susceptibility to antibody-mediated autoimmune disease.

OBJECTIVE

To estimate the prevalence of NMOSD in SLE and investigate the immunogenetic background for an association of NMOSD and SLE.

METHODS

The study included a predominantly population-based cohort with clinical and serological investigations of 208 patients with SLE, followed prospectively since 1995. All patients received immunosuppressive treatment. NMOSD was evaluated retrospectively based on the 2015 International Panel for NMOSD Diagnosis (IPND) criteria. Polymorphisms in programmed cell death protein 1 (PDCD-1) PD-1.3 G/A were genotyped. AGP4-IgG and other autoantibodies, including myelin oligodendrocyte glycoprotein (MOG), was determined blinded to clinical diagnosis.

RESULTS

Of 208 patients with SLE, 45(22%) had neuropsychiatric (NP) SLE, and CNS involvement predominated in 30 of 45 (67%) patients. Serum AQP4-IgG was detected in 2 of 30 (6.7%) neuropsychiatric SLE (NPSLE) patients both of whom had myelitis and antiphospholipid syndrome; one patient also had myasthenia gravis. None had MOG-IgG. PD-1.3A allele was not associated with SLE nor with NPSLE.

CONCLUSION

AQP4-IgG autoimmune syndrome may rarely co-exist with SLE, and such patients have other NMOSD-typical syndromes such as myelitis.

MOG-IgG in NMO and related disorders: a multicenter study of 50 patients. Part 2: Epidemiology, clinical presentation, radiological and laboratory features, treatment responses, and long-term outcome

BACKGROUND

A subset of patients with neuromyelitis optica spectrum disorders (NMOSD) has been shown to be seropositive for myelin oligodendrocyte glycoprotein antibodies (MOG-IgG).

OBJECTIVE

To describe the epidemiological, clinical, radiological, cerebrospinal fluid (CSF), and electrophysiological features of a large cohort of MOG-IgG-positive patients with optic neuritis (ON) and/or myelitis (n = 50) as well as attack and long-term treatment outcomes.

METHODS

Retrospective multicenter study.

RESULTS

The sex ratio was 1:2.8 (m:f). Median age at onset was 31 years (range 6-70). The disease followed a multiphasic course in 80 % (median time-to-first-relapse 5 months; annualized relapse rate 0.92) and resulted in significant disability in 40 % (mean follow-up 75 ± 46.5 months), with severe visual impairment or functional blindness (36 %) and markedly impaired ambulation due to paresis or ataxia (25 %) as the most common long-term sequelae. Functional blindess in one or both eyes was noted during at least one ON attack in around 70 %. Perioptic enhancement was present in several patients. Besides acute tetra-/paraparesis, dysesthesia and pain were common in acute myelitis (70 %). Longitudinally extensive spinal cord lesions were frequent, but short lesions occurred at least once in 44 %. Fourty-one percent had a history of simultaneous ON and myelitis. Clinical or radiological involvement of the brain, brainstem, or cerebellum was present in 50 %; extra-opticospinal symptoms included intractable nausea and vomiting and respiratory insufficiency (fatal in one). CSF pleocytosis (partly neutrophilic) was present in 70 %, oligoclonal bands in only 13 %, and blood-CSF-barrier dysfunction in 32 %. Intravenous methylprednisolone (IVMP) and long-term immunosuppression were often effective; however, treatment failure leading to rapid accumulation of disability was noted in many patients as well as flare-ups after steroid withdrawal. Full recovery was achieved by plasma exchange in some cases, including after IVMP failure. Breakthrough attacks under azathioprine were linked to the drug-specific latency period and a lack of cotreatment with oral steroids. Methotrexate was effective in 5/6 patients. Interferon-beta was associated with ongoing or increasing disease activity. Rituximab and ofatumumab were effective in some patients. However, treatment with rituximab was followed by early relapses in several cases; end-of-dose relapses occurred 9-12 months after the first infusion. Coexisting autoimmunity was rare (9 %). Wingerchuk's 2006 and 2015 criteria for NMO(SD) and Barkhof and McDonald criteria for multiple sclerosis (MS) were met by 28 %, 32 %, 15 %, 33 %, respectively; MS had been suspected in 36 %. Disease onset or relapses were preceded by infection, vaccination, or pregnancy/delivery in several cases.

CONCLUSION

Our findings from a predominantly Caucasian cohort strongly argue against the concept of MOG-IgG denoting a mild and usually monophasic variant of NMOSD. The predominantly relapsing and often severe disease course and the short median time to second attack support the use of prophylactic long-term treatments in patients with MOG-IgG-positive ON and/or myelitis.

Neuromyelitis optica spectrum disorder coinciding with hematological immune disease: A case report

INTRODUCTION

Recently defined consensus criteria for the diagnosis of neuromyelitis optica spectrum disorders (NMOSD) allow establishing the diagnosis in patients without elevated AQP4-Ab and optic nerve involvement. According to the new extended definition, NMOSD is closely associated with extensive spinal cord inflammation occurring in the course of systemic autoimmune diseases as sarcoidosis or lupus erythematodes. NMOSD occurring in the course of hematological disease have not yet been reported in the literature.

CASE REPORT

A 38 year old male subsequently developed thrombocytopenia, hemolytic anemia and agranulocytosis over a 23 month period. Three months after an episode of agranulocytosis, he noticed ascending sensory disturbances and progressive weakness of his legs. Within two days, symptoms worsened to give almost complete paraplegia and loss of sensation below a midthoracic level. MRI revealed signal hyperintensity and edema in T2-weighted sequences reaching from the 2nd cervical to the 9th thoracic vertebral body. Two years later, he developed a second episode with lesions in the spinal cord and periventricular areas of brain stem and thalamus.

CONCLUSION

The relapsing time course and the topographical pattern of central nervous system lesions restricted to axial brain structures and the spinal cord fulfill the criteria that have recently been defined for AQP4-Ab-negative NMO-spectrum disease. Systematic studies on the association of hematological autoimmune phenomena and spinal cord disease are needed to clarify whether this coincidence is just a casual phenomenon or whether it points to a yet undiscovered but perhaps therapeutically interesting link of immunological mechanisms affecting both organ systems.

A Systematic Review of Peripheral and Central Nervous System Involvement of Rheumatoid Arthritis, Systemic Lupus Erythematosus, Primary Sjögren's Syndrome, and Associated Immunological Profiles

Both central (CNS) and peripheral nervous system (PNS) complications are frequent and varied in connective tissue diseases. A systematic review was conducted between 1989 and 2014 in the databases Medline, Scopus, and Cochrane Library using the search terms, peripheral and central nervous complications and immunological profiles, to identify studies in specific connective tissue disorders such as rheumatoid arthritis, systemic lupus erythematosus, and primary Sjögren's syndrome. A total of 675 references were identified, of which 118 were selected for detailed analysis and 22 were included in the final review with a total of 2338 participants. Our search focused only on studies upon connective tissue disorders such as rheumatoid arthritis, systemic lupus erythematosus, and primary Sjögren's syndrome associated with seroimmunological data. The reported prevalence of CNS involvement ranges from 9 to 92% across the reported studies. However, the association between CNS and PNS manifestations and seroimmunological profiles remains controversial. Τo date, no laboratory test has been shown as pathognomonic neither for CNS nor for PNS involvement.

Ocular manifestations in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) can involve many parts of the eye, including the eyelid, ocular adnexa, sclera, cornea, uvea, retina and optic nerve. Ocular manifestations of SLE are common and may lead to permanent blindness from the underlying disease or therapeutic side effects. Keratoconjunctivitis sicca is the most common manifestation. However, vision loss may result from involvement of the retina, choroid and optic nerve. Ocular symptoms are correlated to systemic disease activity and can present as an initial manifestation of SLE. The established treatment includes prompt systemic corticosteroids, steroid-sparing immunosuppressive drugs and biological agents. Local ocular therapies are options with promising efficacy. The early recognition of disease and treatment provides reduction of visual morbidity and mortality.

Aquaporin-4 antibody testing: direct comparison of M1-AQP4-DNA-transfected cells with leaky scanning versus M23-AQP4-DNA-transfected cells as antigenic substrate

BACKGROUND

Neuromyelitis optica (NMO, Devic syndrome) is associated with antibodies to aquaporin-4 (NMO-IgG/AQP4-Ab) in the majority of cases. NMO-IgG/AQP4-Ab seropositivity in patients with NMO and its spectrum disorders has important differential diagnostic, prognostic and therapeutic implications. So-called cell-based assays (CBA) are thought to provide the best AQP4-Ab detection rates.

OBJECTIVE

To compare directly the AQP4-IgG detection rates of the currently most widely used commercial CBA, which employs cells transfected with a full-length (M1)-human AQP4 DNA in a fashion that allows leaky scanning (LS) and thus expression of M23-AQP4 in addition to M1-AQP, to that of a newly developed CBA from the same manufacturer employing cells transfected with human M23-AQP4-DNA.

METHODS

Results from 368 serum samples that had been referred for routine AQP4-IgG determination and had been tested in parallel in the two assays were compared.

RESULTS

Seventy-seven out of 368 samples (20.9%) were positive for NMO-IgG/AQP4-Ab in at least one assay. Of these, 73 (94.8%) were positive in both assays. A single sample (1.3%) was exclusively positive in the novel assay; three samples (3.9%) were unequivocally positive only in the 'classic' assay due to high background intensity in the novel assay. Both median fluorescence intensity and background intensity were higher in the new assay.

CONCLUSIONS

This large study did not reveal significant differences in AQP4-IgG detection rates between the 'classic' CBA and a new M23-DNA-based CBA. Importantly, our results largely re-affirm the validity of previous studies that had used the 'classic' AQP4-CBA to establish NMO-IgG/AQP4-Ab seropositivity rates in NMO and in a variety of NMO spectrum disorders.

Neuromyelitis optica: clinical features, immunopathogenesis and treatment

The term 'neuromyelitis optica' ('Devic's syndrome', NMO) refers to a syndrome characterized by optic neuritis and myelitis. In recent years, the condition has raised enormous interest among scientists and clinical neurologists, fuelled by the detection of a specific serum immunoglobulin (Ig)G reactivity (NMO-IgG) in up to 80% of patients with NMO. These autoantibodies were later shown to target aquaporin-4 (AQP4), the most abundant water channel in the central nervous system (CNS). Here we give an up-to-date overview of the clinical and paraclinical features, immunopathogenesis and treatment of NMO. We discuss the widening clinical spectrum of AQP4-related autoimmunity, the role of magnetic resonance imaging (MRI) and new diagnostic means such as optical coherence tomography in the diagnosis of NMO, the role of NMO-IgG, T cells and granulocytes in the pathophysiology of NMO, and outline prospects for new and emerging therapies for this rare, but often devastating condition.

Aquaporin-4 antibodies (NMO-IgG) as a serological marker of neuromyelitis optica: a critical review of the literature

Antibodies to aquaporin-4 (called NMO-IgG or AQP4-Ab) constitute a sensitive and highly specific serum marker of neuromyelitis optica (NMO) that can facilitate the differential diagnosis of NMO and classic multiple sclerosis. NMO-IgG/AQP4-Ab seropositive status has also important prognostic and therapeutic implications in patients with isolated longitudinally extensive myelitis (LETM) or optic neuritis (ON). In this article, we comprehensively review and critically appraise the existing literature on NMO-IgG/AQP4-Ab testing. All available immunoassays-including tissue-based (IHC), cell-based (ICC, FACS) and protein-based (RIPA, FIPA, ELISA, Western blotting) assays-and their differential advantages and disadvantages are discussed. Estimates for sensitivity, specificity, and positive and negative likelihood ratios are calculated for all published studies and accuracies of the various immunoassay techniques compared. Subgroup analyses are provided for NMO, LETM and ON, for relapsing vs. monophasic disease, and for various control groups (eg, MS vs. other controls). Numerous aspects of NMO-IgG/AQP4-Ab testing relevant for clinicians (eg, impact of antibody titers and longitudinal testing, indications for repeat testing, relevance of CSF testing and subclass analysis, NMO-IgG/AQP4-Ab in patients with rheumatic diseases) as well as technical aspects (eg, AQP4-M1 vs. AQP4-M23-based assays, intact AQP4 vs. peptide substrates, effect of storage conditions and freeze/thaw cycles) and pitfalls are discussed. Finally, recommendations for the clinical application of NMO-IgG/AQP4-Ab serology are given.

Diagnosis of multiple sclerosis

This chapter will serve as a guide for the diagnosis of multiple sclerosis (MS). Primary aims include a review of both the common and atypical clinical manifestations of MS, a detailed discussion of the alternative diagnoses which can mimic MS, as well as a review of the current established diagnostic criteria and a history of their development. It will also review the distinct disease courses and MS variants. The goal of the chapter is to facilitate the diagnostic process for clinicians so that they may expedite early diagnosis and treatment in an effort to alter disease outcomes and ultimately improve patients' quality of life.

'Spinal amaurosis' (1841). On the early contribution of Edward Hocken to the concept of neuromyelitis optica

While the history of classical multiple sclerosis has been extensively studied, only little is known about the early history of neuromyelitis optica (Devic's syndrome). Here we discuss a forgotten report by Edward Octavius Hocken (1820-1845) published in The Lancet in 1841. Hocken's report is important from a historic point of view for two reasons. Firstly, apart from a French language report by Antoine Portal, no earlier case of spinal cord inflammation and amaurosis is known. Secondly and much more importantly, Hocken, who upon his untimely death at the age of just 25 years was honoured by his contemporaries as a "precocious talent" of "very early reputation", in that article propagated the novel concept of 'spinal amaurosis', i.e. the concept of acute amaurosis and spinal cord disease being pathogenetically connected. Hocken's ideas predate Devic and Gault's seminal works on 'neuromyelitis optica' by more than 50 years.

Update on the diagnosis and treatment of neuromyelitis optica: recommendations of the Neuromyelitis Optica Study Group (NEMOS)

Neuromyelitis optica (NMO, Devic’s syndrome), long considered a clinical variant of multiple sclerosis, is now regarded as a distinct disease entity. Major progress has been made in the diagnosis and treatment of NMO since aquaporin-4 antibodies (AQP4-Ab; also termed NMO-IgG) were first described in 2004. In this review, the Neuromyelitis Optica Study Group (NEMOS) summarizes recently obtained knowledge on NMO and highlights new developments in its diagnosis and treatment, based on current guidelines, the published literature and expert discussion at regular NEMOS meetings. Testing of AQP4-Ab is essential and is the most important test in the diagnostic work-up of suspected NMO, and helps to distinguish NMO from other autoimmune diseases. Furthermore, AQP4-Ab testing has expanded our knowledge of the clinical presentation of NMO spectrum disorders (NMOSD). In addition, imaging techniques, particularly magnetic resonance imaging of the brain and spinal cord, are obligatory in the diagnostic workup. It is important to note that brain lesions in NMO and NMOSD are not uncommon, do not rule out the diagnosis, and show characteristic patterns. Other imaging modalities such as optical coherence tomography are proposed as useful tools in the assessment of retinal damage. Therapy of NMO should be initiated early. Azathioprine and rituximab are suggested as first-line treatments, the latter being increasingly regarded as an established therapy with long-term efficacy and an acceptable safety profile in NMO patients. Other immunosuppressive drugs, such as methotrexate, mycophenolate mofetil and mitoxantrone, are recommended as second-line treatments. Promising new therapies are emerging in the form of anti-IL6 receptor, anti-complement or anti-AQP4-Ab biologicals.

Aquaporin-4 antibodies (NMO-IgG) as a serological marker of neuromyelitis optica: a critical review of the literature

Antibodies to aquaporin-4 (called NMO-IgG or AQP4-Ab) constitute a sensitive and highly specific serum marker of neuromyelitis optica (NMO) that can facilitate the differential diagnosis of NMO and classic multiple sclerosis. NMO-IgG/AQP4-Ab seropositive status has also important prognostic and therapeutic implications in patients with isolated longitudinally extensive myelitis (LETM) or optic neuritis (ON). In this article, we comprehensively review and critically appraise the existing literature on NMO-IgG/AQP4-Ab testing. All available immunoassays-including tissue-based (IHC), cell-based (ICC, FACS) and protein-based (RIPA, FIPA, ELISA, Western blotting) assays-and their differential advantages and disadvantages are discussed. Estimates for sensitivity, specificity, and positive and negative likelihood ratios are calculated for all published studies and accuracies of the various immunoassay techniques compared. Subgroup analyses are provided for NMO, LETM and ON, for relapsing vs. monophasic disease, and for various control groups (eg, MS vs. other controls). Numerous aspects of NMO-IgG/AQP4-Ab testing relevant for clinicians (eg, impact of antibody titers and longitudinal testing, indications for repeat testing, relevance of CSF testing and subclass analysis, NMO-IgG/AQP4-Ab in patients with rheumatic diseases) as well as technical aspects (eg, AQP4-M1 vs. AQP4-M23-based assays, intact AQP4 vs. peptide substrates, effect of storage conditions and freeze/thaw cycles) and pitfalls are discussed. Finally, recommendations for the clinical application of NMO-IgG/AQP4-Ab serology are given.

The case of the Marquis de Causan (1804): an early account of visual loss associated with spinal cord inflammation

The recent discovery of disease specific and pathogenic autoantibodies in neuromyelitis optica (NMO, Devic's disease) has revived the interest in this intriguing yet often devastating condition. While the history of classic multiple sclerosis has been studied extensively, only very little is known so far about the early history of NMO. Here we discuss a now forgotten report by the famous French anatomist and pathologist Antoine Portal (1742-1832), first physician to Louis XVIII and founding and lifelong president of the Académie Nationale de Médecine. Portal's report, which fascinated some of the most renowned 19th century pioneers in the field of neurology but fell into oblivion later, represents the first account of visual loss in a patient with spinal cord inflammation but no brain pathology in the Western literature known so far--published more than 60 years prior to Thomas Clifford Allbutt's much cited note on a patient with myelitis and a "sympathetic eye disorder".