Neuromyelitis optica: An update

Rituximab efficacy at different initial and maintenance doses in neuromyelitis optica spectrum disorder: Experience from a national health institute in México

BACKGROUND

NMOSD is an inflammatory disorder of the central nervous system that primarily affects the optic nerves and spinal cord. Rituximab (RTX) is a monoclonal antibody directed against CD20, an epitope expressed on pre-B and mature B cells. It has of wide use in several antibody-mediated autoimmune diseases.

OBJECTIVES

To demonstrate RTX clinical efficacy at different initial and maintenance doses administered in patients with NMOSD.

METHODS

In this retrospective/observational study we recruited subjects with NMOSD with at least one RTX infusion. Annual relapse rates (ARR) were compared in several induction and maintenance regimens with RTX in 66 patients with NMOSD.

RESULTS

Fifty-four (81.8%) were female and two thirds (66.7%) had positive anti-AQP4 antibodies. The most prevalent induction and maintenance regimens were 1000 mg on days 1 and 15 (51.5%) and 1000 mg every 6 months (40.9%), respectively. Overall, the annual relapse rate (ARR) decreased from 1.15 to 0.46 with RTX (p < 0.001). In patients with persistent relapses, the ARR decreased from 1.66 to 1.22, representing a relative risk reduction of 24%. Treatment with RTX decreased the ARR from 1.36 to 0.4 in the 500 mg induction and maintenance dose subgroup, and from 0.7 to 0.4 in the 1000 mg induction and maintenance dose subgroup.

CONCLUSION

RTX treatment in patients with NMOSD demonstrated a marked and sustained reduction in the ARR, regardless of induction and maintenance regimens. EDSS stability was observed, even in patients with active and severe NMOSD.

Pregnancy-Related Immune Changes and Demyelinating Diseases of the Central Nervous System

Demyelinating diseases of the central nervous system comprise a heterogeneous group of autoimmune disorders characterized by myelin loss with relative sparing of axons occurring on a background of inflammation. Some of the most common demyelinating diseases are multiple sclerosis, acute disseminated encephalomyelitis, and neuromyelitis optica spectrum disorders. Besides showing clinical, radiological, and histopathological features that complicate their diagnosis, demyelinating diseases often involve different immunological processes that produce distinct inflammatory patterns. Evidence of demyelination diseases derives mostly from animal studies of experimental autoimmune encephalomyelitis (EAE), a model that relies on direct antibody–antigen interactions induced by encephalitogenic T cells. Pregnancy is characterized by non-self-recognition, immunomodulatory changes and an altered Th1/Th2 balance, generally considered a Th2-type immunological state that protects the mother from infections. During pregnancy, the immune response of patients with autoimmune disease complicated with pregnancy is different. Immune tolerance in pregnancy may affect the course of some diseases, which may reach remission or be exacerbated. In this review, we summarize current knowledge on the immune status during pregnancy and discuss the relationship between pregnancy-related immune changes and demyelinating diseases of the central nervous system.

Mimickers of neuropsychiatric manifestations in systemic lupus erythematosus

Systemic lupus erythematosus (SLE), presenting with new onset or worsening neuropsychiatric (NP) symptoms, is a challenge in clinical practice. Mimickers such as infections, drug-induced side effects, metabolic abnormalities, malignancies, and alcohol-related disorders have to be excluded, before attributing the manifestations to disease activity. Proper diagnosis is essential to guide adequate management and reduce morbidity and mortality. In this review article, we will highlight clinical, laboratorial, and neuroradiological features that are helpful to assist in the differential diagnosis.

Resilience and depression/anxiety symptoms in multiple sclerosis and neuromyelitis optica spectrum disorder

BACKGROUND

Depression and anxiety are common in multiple sclerosis (MS) and recently, studies on these symptoms in neuromyelitis optica spectrum disorder (NMOSD) are increasing. Previous studies suggest that these symptoms have negative effects on the quality of life. Resilience has garnered more interest as one of the protective factors that works to prevent psychiatric symptoms in past decades. There exist a few studies, however, regarding the effects of resilience on these psychiatric symptoms in MS/NMOSD.

OBJECTIVE

The aim of this study was to clarify the relationships between resilience, psychiatric symptoms, and QOL in patients with MS/NMOSD.

METHOD

Seventy-seven patients with MS/NMOSD participated in this study. They completed several questionnaires (Beck Depression Inventory-Second edition, Hospital Anxiety and Depression Scale, the Japanese version of the Resilience scale [RS], and Japanese version of Multiple Sclerosis Quality of Life-54). We also collected demographic and clinical data including age, sex, physical disability level (measured with the Expanded Disability Status Scale [EDSS]), and disease duration of the participants.

RESULTS

The EDSS scores showed significant negative correlations with QOL, unlike disease duration, which did not correlate with either the psychiatric symptoms or QOL. Additionally, there was no significant correlation between RS scores and EDSS scores or disease duration. We also found that resilience showed a significant negative correlation with psychiatric symptoms, and positive correlation with QOL.

CONCLUSION

These results suggest that resilience may serve to prevent or reduce depression/anxiety symptoms and maintain the QOL regardless of the physical disability level.

Frequency of autoimmune disorders and autoantibodies in patients with neuromyelitis optica

OBJECTIVE

The aim of this study was to report the frequency of autoimmune disorders and autoantibodies in 22 patients with neuromyelitis optica (NMO), as well as whether the seropositivity for autoantibodies differs between anti-aquaporin 4 (AQP4) positive and AQP4 negative NMO patients.

METHODS

Demographic, medical records, and a profile of autoantibodies were evaluated in 22 NMO patients, including AQP4, anti-thyroid-stimulating hormone receptor, antinuclear antibodies (ANA), anti-thyroperoxidase (anti-TPO), anti-thyroglobulin (anti-Tg), anti-double-stranded DNA, anti-neutrophil cytoplasmic, anti-cyclic citrullinate peptide, rheumatoid factor, anti-SSA/Ro, anti-SSB/La, anti-Smith antibodies (anti-Sm), anti-ribonucleoprotein, anti-nucleosome, and anti-Scl70. Thyroid-stimulating hormone and free thyroxin were measured.

RESULTS

The frequency of women was higher than men (95.5% vs. 4.5%) and 68.2% were Afro-Brazilians. Six (27.3%) patients presented other autoimmune disorders, such as Hashimoto thyroiditis (n=2), Graves' disease (n=1), juvenile idiopathic arthritis (n=1), systemic lupus erythematosus and systemic sclerosis (n=1), and Raynaud's phenomenon (n=1). The most frequent autoantibodies were anti-AQP4 (54.5%), anti-nucleosome (31.8%), ANA (27.3%), anti-TPO (22.7%), and anti-Tg (22.7%). Difference was not observed in the frequency of autoimmune disorders when the patients were compared according to their anti-AQP4 status.

CONCLUSION

The results of the present study underscored that the NMO patients present high frequency of autoantibodies against cellular antigens and the presence of autoimmune disorders. Further studies with large number of NMO patients may contribute to advances in the understanding of NMO disease mechanisms.

Clinical proteomics of enervated neurons

The dynamic field of neurosciences entails ever increasing search for molecular mechanisms of disease states, especially in the domain of neurodegenerative disorders. The previous century heralded the techniques in proteomics when indexing of the human proteomes relating to various disease conditions became important. Early stage research in certain diseases or pathological conditions requires a more holistic approach of first discovering the proteins of interest for the condition. Despite its limitations, proteomics is one of the most powerful techniques available to us today to dissect the molecular scenario in a particular disease situation. In this review we will discuss about the current clinical research in neurodegenerative disorders that employ proteomics techniques. We will specifically focus on our understanding of Alzheimer’s disease, traumatic spinal cord injury and neuromyelitis optica. Discussions will include ongoing worldwide research in these areas, research in India and specifically our laboratory in these domains of neurodegenerative conditions.

Epidemiological, clinical, and immunological characteristics of neuromyelitis optica: A review

The aim of this study was to review the epidemiological and clinical characteristics of neuromyelitis optica (NMO) and the immunopathological mechanisms involved in the neuronal damage. NMO is an inflammatory demyelinating autoimmune disease of the central nervous system that most commonly affects the optic nerves and spinal cord. NMO is thought to be more prevalent among non-Caucasians and where multiple sclerosis (MS) prevalence is low. NMO follows a relapsing course in more than 80-90% of cases, which is more commonly in women. It is a complex disease with an interaction between host genetic and environmental factors and the main immunological feature is the presence of anti-aquaporin 4 (AQP4) antibodies in a subset of patients. NMO is frequently associated with multiple other autoantibodies and there is a strong association between NMO with other systemic autoimmune diseases. AQP4-IgG can cause antibody-dependent cellular cytotoxicity (ADCC) when effector cells are present and complement-dependent cytotoxicity (CDC) when complement is present. Acute therapies, including corticosteroids and plasma exchange, are designed to minimize injury and accelerate recovery. Several aspects of NMO pathogenesis remain unclear. More advances in the understanding of NMO disease mechanisms are needed in order to identify more specific biomarkers to NMO diagnosis.

Epidemiology of neuromyelitis optica in the world: a systematic review and meta-analysis

Background. Neuromyelitis optica (Devic's disease) is a severe autoimmune inflammatory disorder of the central nervous system. Epidemiological aspects of NMO have not been systemically reviewed. In this study we systematically reviewed and assessed the quality of studies reporting the incidence and/or prevalence of NMO across the world. Methods. A comprehensive literature search using MEDLINE, EMBASE, and Web of Science for the terms “Neuromyelitis optica,” “devic disease,” “incidence,” “prevalence,” and “epidemiology” was conducted on January 31, 2015. Study quality was assessed using an assessment tool based on recognized guidelines and designed specifically for this study. Results. A total of 216 studies were initially identified, with only 9 meeting the inclusion criteria. High level of heterogeneity amongst studies precluded a firm conclusion. Incidence data were found in four studies and ranged from 0.053 per 100,000 per year in Cuba to 0.4 in Southern Denmark. Prevalence was reported in all studies and ranged from 0.51 per 100,000 in Cuba to 4.4 in Southern Denmark. Conclusion. This review reveals the gaps that still exist in the epidemiological knowledge of NMO in the world. Published studies have different qualities and methodology precluding a robust conclusion. Future researches focusing on epidemiological features of NMO in different nations and different ethnic groups are needed.

Risk factors for multiple sclerosis, neuromyelitis optica and transverse myelitis

Background:

Little is known about risk factors for neuromyelitis optica (NMO) or transverse myelitis (TM).

Objective:

The objective of this paper is to evaluate whether established multiple sclerosis (MS) risk factors, including smoking history, a history of infectious mononucleosis (IM), anti-EBNA1 Ab titers and HLA-DR15 are associated with NMO or TM.

Methods:

We conducted a case-control study among participants in the Accelerated Cure Project for Multiple Sclerosis (ACP) Repository, which includes patients with MS, NMO and TM. Controls include related and unrelated individuals without evidence of demyelinating disease. Analyses included 1237 cases of MS, 98 cases of NMO, 133 cases of TM and 488 healthy controls. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to assess the association between smoking, HLA-DR15, anti-EBNA1 Ab titers and a history of IM adjusting for gender, study site and ethnicity.

Results:

Overall, the association between smoking, IM, HLA-DR15 and anti-EBNA1 Ab titers and odds of MS were as expected and no significant interactions were observed. However, there was little evidence of association between these MS risk factors and odds of NMO or TM.

Conclusions:

Established MS risk factors do not appear to be associated with susceptibility to TM or NMO and, among MS patients, these risk factors appear to act independently.

Spectral-domain optical coherence tomography of retinal nerve fiber layer thickness in NMO patients

BACKGROUND

Neuromyelitis optica (NMO) is a demyelinating syndrome of the central nervous system. NMO might be underdiagnosed at early stages when patients have not yet developed the full spectrum of disease. The aim of this study was to analyze the retinal nerve fiber layer (RNFL) with optical coherence tomography (OCT) and to compare RNFL measurements between NMO patients, patients with relapsing-remitting multiple sclerosis (RRMS), and healthy controls to determine whether differences in RNFL thickness could be an early diagnostic marker for NMO.

METHODS

In a cross-sectional study, eyes of 25 NMO patients, 25 RRMS patients, and 50 healthy controls underwent RNFL measurements by OCT. Clinical parameters were collected by history and chart review. Pairwise Wilcoxon rank sum tests with Holm correction were used to compare means of RNFL thickness among 6 groups (NMO, RRMS, and healthy control) of patients [without or with 1 or more episode of optic neuritis (ON)]. The association between RNFL thickness and patient characteristics for NMO group was examined via linear mixed-effects models (adjusting for within-patient intereye correlations and history of ON, where appropriate).

RESULTS

Based on the pairwise Wilcoxon rank sum tests with Holm correction, significant differences were found between NMO with 1 episode of ON and non-ON eyes (mean RNFL 63.7 vs 97.0 µm, P < 0.0001), multiple sclerosis (MS) non-ON eyes, and controls (RNFL 93.2 vs 98.4 µm, P = 0.03). No significant differences were found between NMO and MS with 1 attack of ON eyes (RNFL 63.7 vs 73.9 µm, P = 0.46), NMO non-ON eyes and healthy controls (RNFL 97.0 vs 98.4 µm, P = 0.56), and NMO non-ON and MS non-ON (RNFL 97.0 vs 93.2 µm, P = 0.56). For NMO group, RNFL thickness was associated with a history of ON (P < 0.001) but not with disability or disease duration when adjusting for the history of ON (P > 0.1).

CONCLUSIONS

RNFL in NMO is not different enough to distinguish NMO ON from MS ON eyes, but the intereye difference in RFNL with a history of unilateral ON may be a better diagnostic marker for NMO.

MRI in transverse myelitis

Transverse myelitis is an acute inflammatory disease of the spinal cord, characterized by rapid onset of bilateral neurological symptoms. Weakness, sensory disturbance, and autonomic dysfunction evolve over hours or days, most progressing to maximal clinical severity within 10 days of onset. At maximal clinical severity, half will have a paraparesis, and almost all patients have sensory disturbance and bladder dysfunction. Residual disability is divided equally between severe, moderate and minimal or none. The causes of transverse myelitis are diverse; etiologies implicated include demyelinating conditions, collagen vascular disease, and parainfectious causes, however, despite extensive diagnostic work-up many cases are considered idiopathic. Due to heterogeneity in pathogenesis, and the similarity of its clinical presentation with those of various noninflammatory myelopathies, transverse myelitis has frequently been viewed as a diagnostic dilemma. However, as targeted therapies to optimize patient outcome develop, timely identification of the underlying etiology is becoming increasingly important. In this review, we describe the imaging and clinical features of idiopathic and disease-associated transverse myelitis and its major differentials, with discussion of how MR imaging features assist in the identification of various sub-types of transverse myelitis. We will also discuss the potential for advanced MR techniques to contribute to diagnosis and prognostication.

A case of neuromyelitis optica misdiagnosed as cervicogenic headache

Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system associated with longitudinally extensive myelitis and optic neuritis. It is characterized by relapses that lead to blindness and paralysis sequelaes. But, this is rare disease; therefore high clinical suspicion for a correct diagnosis and proper examinations are not easy. However, early diagnosis is essential to prevent sequelae. We report the case of NMO with headache. A 30-year male patient who suffered headache visited our pain clinic because of aggravated pain despite treatment. The cause of the pain was revealed as NMO by more detailed previous history and examination.

Relapsing optic neuritis: a multicentre study of 62 patients

Background:

Optic neuritis (ON) may be the first symptom of a central nervous system demyelinating, systemic or infectious disease but few patients experience recurrent episodes and have a negative workup.

Objective:

This disorder, named relapsing optic neuritis (RON), is poorly described in the literature and still presents a particular challenge in diagnosis and management.

Methods:

We describe the clinical, laboratory, magnetic resonance imaging (MRI) and disability course of RON in a French cohort of 62 patients, based on a multicentre, retrospective, observational study.

Results:

In our cohort, we identified two distinct groups of RON patients. The first is characterised by relapsing inflammatory optic neuritis (RION, 68%), which is non-progressive, whereas the second presented as a chronic relapsing inflammatory optic neuritis (CRION, 32%), which is progressive. We have noted more cases with steroid dependence in the CRION group than the RION group (42% vs 10%). The long-term visual prognosis was more severe in CRION patients and neuromyelitis optica-immunoglobulin G (NMO-IgG)-positive patients.

Conclusion:

RON is likely a separate entity corresponding to an autoimmune disease that differs from multiple sclerosis (MS), NMO and vasculitis. We provide a new classification system based on a better understanding of RON which could allow an improved management by early treatment of poor prognosis forms.

Relapsing Devic's disease in a child

Neuromyelitis optica (NMO) also named Devic's disease is an acute demyelinating disorder that primarily affects the spinal cord and optic nerves. NMO can occur rarely in children but pediatric NMO cases need specific consideration owing to possible poor visual and motor outcome. In this case report, a NMO case of a 10-year-old girl with bilateral optic neuritis, cerebral, and spinal cord involvement is presented.

Unusual manifestations of pediatric neuromyelitis optica

Neuromyelitis optica is a rare, severe idiopathic disease that predominantly involves optic nerves and spinal cord. Main clinical features of neuromyelitis optica are visual loss, paraparesis or tetraparesis, sensory loss, and sphincter dysfunction. A 13-year-old girl with vision loss and behavioral change was admitted. Her behavioral changes concerned demanding everything, eating cacik (a kind of meal prepared by yogurt) continuously, calling everyone "father," and self-throttling during the last 1 month, and blurred vision started 15 days ago. On cranial magnetic resonance imaging (MRI), multiple lesions were seen. The patient was admitted 40 days later with walking difficulty. There were lesions in the medulla and cervical spinal cord on MRI. Neuromyelitis optica was diagnosed. Vomiting was the beginning complaint in 2 of 5 hospitalizations later. We conclude that neuromyelitis optica may involve atypical symptoms such as behavioral change and vomiting. Atypical presentations may delay diagnosis. Vomiting may be a recurrence messenger.

Cerebrospinal fluid IL-21 levels in Neuromyelitis Optica and multiple sclerosis

BACKGROUND

Neuromyelitis optica (NMO) and multiple sclerosis (MS) are inflammatory demyelinating diseases of human central nervous system (CNS) with complex pathogenesis. IL-21/IL-21R regulates activation, proliferation and survival of both T cells and B cells, which are involved in the pathogenesis of NMO and MS. High levels of serum IL-21 were observed in NMO patients. However, concentration of cerebrospinal fluid (CSF) IL-21 in MS and NMO patients still remain unknown.

OBJECT

To detect the CSF concentration of IL-21 in NMO and MS patients and to evaluate its relationship with disease activity, particularly concerned about its impact on humoral immunity.

METHODS

CSF IL-21 was detected by an enzyme-linked immunosorbent assay (ELISA) in NMO patients (n=21), MS patients (n=20) and controls (n=16).

RESULTS

CSF concentration of the IL-21 was noticeably elevated in NMO (p=0.012) and borderline significantly increased in MS (p=0.115). In addition, this occurrence was associated with humoral immune activity as shown by a correlation between IL-21 and complement in NMO cohort (p=0.023) and high IL-21 levels in autoantibody-positive subgroup (p=0.027).

CONCLUSIONS

The concentration of CSF IL-21 was noticeably elevated and might have a positive correlation with humoral immune activity in NMO.

The Brown Norway opticospinal model of demyelination: does it mimic multiple sclerosis or neuromyelitis optica?

Opticospinal demyelinating diseases in humans are mostly characterized by the opticospinal form of multiple sclerosis (MS) and neuromyelitis optica (NMO). Increasing attention has recently focused on astrocyte markers, aquaporin-4 (AQP4) and glial fibrillary acidic protein (GFAP) in these diseases. We induced opticospinal demyelination in Brown Norway rats with soluble recombinant rat myelin oligodendrocyte glycoprotein (1-116) and incomplete Freund's adjuvant. Clinical, MRI, neuropathological and immunological evaluations were performed, with a focus on AQP4 and GFAP. We confirmed the opticospinal phenotype, including extensive myelitis, but also showed the MRI-characterized involvement of the periventricular area. Expression levels of myelin, AQP4 and GFAP showed the early involvement of astrocytes before demyelination in the optic nerve. The overexpression of AQP4 was particularly pronounced in the spinal cord and was concomitant with demyelination and astrocyte apoptosis. The disability scores were correlated with demyelination and inflammation but not with AQP4/GFAP expression. No antibodies against the linear and conformational epitopes of AQP4 were detected. Whereas a NMO-like phenotype was observed in this model, the AQP4/GFAP expression during the disease process was more closely related to opticospinal MS than NMO. However, this model raises the question of a continuum between opticospinal MS and the seronegative NMO subtype.

Neuroimaging in acute transverse myelitis

Transverse myelitis is an acute inflammatory condition. A relatively rare condition, the diversity of causes makes it an important diagnostic challenge. An approach to the classification and work-up standardizes diagnostic criteria and terminology to facilitate clinical research, and forms a useful tool in the clinical work-up for patients at presentation. Its pathogenesis can be grouped into four categories. Imaging appearances can be nonspecific; however, the morphology of cord involvement, enhancement pattern, and presence of coexistent abnormalities on MR imaging can provide clues as to the causes. Neuroimaging is important in identifying subgroups that may benefit from specific treatment.

An astrocyte-specific enhancer of the aquaporin-4 gene functions through a consensus sequence of POU transcription factors in concert with multiple upstream elements

Aquaporin-4, a predominant water channel in the brain, is specifically expressed in astrocyte endfeet and plays a central role in water homeostasis, neuronal activity, and cell migration in the brain. It has two dominant isoforms called M1 and M23, whose mRNA is driven by distinct promoters located upstream of exons 0 and 1 of the aquaporin-4 gene, respectively. To identify cis-acting elements responsible for the astrocyte-specific transcription of M1 mRNA, the promoter activity of the 5'-flanking region upstream of exon 0 in primary cultured mouse astrocytes was examined by luciferase assay, and sequences, where nuclear factors bind, were identified by electrophoretic mobility shift assay. An astrocyte-specific activity enhancing transcription from the M1 promoter was observed within ∼2 kb from the transcriptional start sites of M1 mRNA. At least five elements clustered within the 286-bp region were found to function as a novel astrocyte-specific enhancer. Among the five elements, a consensus sequence of Pit-1/Oct/Unc-86 (POU) transcription factors was indispensable to the astrocyte-specific enhancer since disruption of the POU motif completely abolished the enhancer activity in astrocytes. However, the POU motif alone had little activity, indicating the requirement for cooperation with other upstream elements to exert full enhancer activity.

Notable increased cerebrospinal fluid levels of soluble interleukin-6 receptors in neuromyelitis optica

BACKGROUND

IL-6 is a proinflammatory cytokine which is involved in the maintenance of the humoral response in various autoimmune disorders. Cerebrospinal fluid (CSF) IL-6 has shown to be increased in neuromyelitis optica (NMO). The soluble form of IL-6 receptor (sIL-6R), which links to IL-6, can activate biological responses in cells. Whether or not sIL-6R is altered in NMO has not been clarified.

OBJECTIVE

To measure CSF IL-6 and sIL-6R in NMO and multiple sclerosis (MS) patients, and investigate whether IL-6 and sIL-6R have possible uses as sensitive biomarkers for diseases activity.

METHODS

CSF concentrations of IL-6 and sIL-6R were measured by an ELISA in NMO (n = 22) and MS (n = 18) patients, as well as control subjects (n = 14).

RESULTS

The concentration of IL-6 levels were higher in NMO compared to MS (p = 0.032) and the controls (p = 0.023). The levels of sIL-6R were also higher in NMO compared to MS (p = 0.002) and the controls (p < 0.001). CSF sIL-6R was associated with an Expanded Disability Status Scale score in NMO (p = 0.005) but not in MS (p = 0.891). In the MS subgroup, sIL-6R concentrations were associated with CSF white blood cells (p = 0.034).

CONCLUSIONS

Our study revealed that CSF sIL-6R was increased in NMO patients, and correlated with clinical presentations.

Pencil-thin ependymal enhancement in neuromyelitis optica spectrum disorders

AQP4 water channels are thought to be the target of autoimmune attack in neuromyelitis optica-spectrum disorders (NMOsd). AQP4 are highly expressed on ventricular ependyma. The objective of this study was to describe a novel pattern of linear, 'pencil-thin' enhancement of ventricular ependyma in NMOsd. We report two NMOsd patients with pencil-thin ependymal enhancement along the frontal and occipital horns of lateral ventricles. Differential diagnosis of ependymal enhancement should include NMOsd alongside with infectious and neoplastic etiologies. Pencil-thin ependymal enhancement may be a helpful radiological marker of NMOsd that can be used to differentiate this condition from multiple sclerosis.