A population-based study of neuromyelitis optica in Caucasians

The prevalence, incidence, and clinical assessment of neuromyelitis optica spectrum disorder in patients with demyelinating diseases

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is characterised by recurrent attacks of optic neuritis and transverse myelitis. The purpose of this work was to identify the incidence and prevalence of NMOSD and its clinical characteristics in the population treated for demyelinating diseases in Western Mexico.

MATERIAL AND METHOD

A descriptive, retrospective study was carried out in the Department of Neurology, at the Sub-specialty Medical Unit, Specialties Hospital (known by its Spanish abbreviation UMAE-HE), of the National Western Medical Center (CMNO), Mexican Institute of Social Security (IMSS). A review of the electronic files for all patients with a diagnosis of NMOSD in 2019, was carried out in the State of Jalisco, Mexico.

RESULTS

Fifty-eight patients with NMOSD were included in the study. The incidence was 0.71/100 000 (CI 0.60-0.85) and the prevalence was 1.09/100 000 (CI 0.84-1.42). There were 79.3% women, and 20.6% were men (P = .01). All (100%) patients presented with anti-aquaporin-4 immunoglobulin G, and 89.6% showed seropositivity for anti-aquaporin-4 (CI 82.6-94.9). Magnetic resonance imaging was performed on 100% of patients, where 34.4% were normal, and 65.5% (38) abnormal, presenting with non-specific subcortical lesions (P = 0.04). The initial clinical presentation was optic neuritis (ON) in 58.6%; where 31.0% was bilateral ON, 20.7% was left ON, and 6.9% were right ON; transverse myelitis in 26.0%, area postrema syndrome (APS) in 10.3%, among others.

CONCLUSIONS

The incidence of NMOSD exceeds 0.71/100 000, the prevalence is low at 1.09/100 000, and NMOSD is predominantly found in women.

Sex ratio and age of onset in AQP4 antibody-associated NMOSD: a review and meta-analysis

BACKGROUND

Aquaporin-4 (AQP4) antibody-associated neuromyelitis optica spectrum disorder (NMOSD) is an antibody-mediated inflammatory disease of the central nervous system. We have undertaken a systematic review and meta-analysis to ascertain the sex ratio and mean age of onset for AQP4 antibody associated NMOSD. We have also explored factors that impact on these demographic data.

METHODS

A systematic search of databases was conducted according to the PRISMA guidelines. Articles reporting sex distribution and age of onset for AQP4 antibody-associated NMSOD were reviewed. An initially inclusive approach involving exploration with regression meta-analysis was followed by an analysis of just AQP4 antibody positive cases.

RESULTS

A total of 528 articles were screened to yield 89 articles covering 19,415 individuals from 88 population samples. The female:male sex ratio was significantly influenced by the proportion of AQP4 antibody positive cases in the samples studied (p < 0.001). For AQP4 antibody-positive cases the overall estimate of the sex ratio was 8.89 (95% CI 7.78-10.15). For paediatric populations the estimate was 5.68 (95% CI 4.01-8.03) and for late-onset cases, it was 5.48 (95% CI 4.10-7.33). The mean age of onset was significantly associated with the mean life expectancy of the population sampled (p < 0.001). The mean age of onset for AQP4 antibody-positive cases in long-lived populations was 41.7 years versus 33.3 years in the remainder.

CONCLUSIONS

The female:male sex ratio and the mean age of onset of AQP4 antibody-associated NMOSD are significantly higher than MS. The sex ratio increases with the proportion of cases that are positive for AQP4 antibodies and the mean age of onset increases with population life expectancy.

Spinal Cord Imaging in Multiple Sclerosis and Related Disorders

Spinal cord MRI plays an important role in the diagnosis and prognosis of multiple sclerosis (MS) and related disorders. The ANATOMICAL, pathologic, imaging and prognostic consideriations for the spinal cord for MS and the most important other demyelinating disorders, neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein-associated disease, are reviewed. Finally, differential diagnostic considerations of spinal cord MRI in MS and related disorders are discussed.

AQUAPORIN-4 (AQP-4) IMMUNOGLOBULIN G SEROPOSITIVE NEUROMYELITIS OPTICA: A REVIEW AND CASE REPORT

Background

Neuromyelitis optica spectrum disorder (NMOSD) is a relatively new terminology composed to encompass patients with neuromyelitis optica (NMO) and related immunological conditions. The diagnosis of this condition requires a seropositive aquaporin-4 immunoglobulin G (AQP-4 IgG), the presence of at least one core clinical characteristic and the exclusion of alternative diagnoses. Very few cases have been reported in sub-Saharan Africa.

Objective

The aim of this article is to report a classical case of NMOSD with AQP-4 IgG seropositivity and normal brain, cervical and thoracic MRI findings.

Result

We report a 25-year-old Nigerian woman who presented with recurrent and alternating weakness, pain and numbness of all limbs, associated with episodic painful left-sided tonic spasms and urinary incontinence. She had earlier had symptoms of recurrent, episodic and alternating loss of vision in both eyes, associated with ocular pain.Examination findings revealed an intact mental status, no cranial nerve deficit and no focal limb weakness. Right-sided deep tendon reflexes were exaggerated. Vital signs were within normal limits. Brain MRI, Cervical spine MRI and Thoracic spine MRI all revealed normal findings. Serum aquaporin-4 IgG assay returned positive with a titer of 1:32.She was commenced on high dose steroids and there was gradual improvement of symptoms.

Conclusion

These findings confirmed the diagnosis of neuromyelitis optica spectrum disorder, and satisfies the diagnostic criteria published in 2015 by the International Panel for NMO Diagnosis (IPND).

Family aggregation and prevalence of other autoimmune diseases in SAPHO syndrome

Objective

SAPHO (Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis) syndrome is a heterogeneous disease that clinically manifests as chronic inflammatory osteoarticular and dermatological lesions. Few reports have described familial clustering of SAPHO syndrome cases. This research aimed to illustrate the family aggregation of SAPHO syndrome and investigate the prevalence of autoimmune disorders among SAPHO syndrome patients and first-degree relatives in a large cohort.

Methods

We retrospectively reviewed the medical records of 233 SAPHO patients diagnosed at Peking Union Medical College Hospital. Direct phone calls were made to each first-degree relatives. All relatives of the patients who reported SAPHO syndrome were asked for a detailed outpatient evaluation.

Results

A total of 233 patients and 1227 first-degree relatives were recruited. Six (2.6 %) patients had positive SAPHO family history, including four mother-daughter pairs and two sister pairs. Twenty-one (9.0 %) patients presented at least one kind of autoimmune disease, including 12 rheumatoid arthritis and 4 ulcerative colitis cases. Fifty-eight (24.9 %) SAPHO syndrome patients had 68 (5.5 %) first-degree relatives with at least one autoimmune disorder. The palmoplantar pustulosis, psoriasis vulgaris, and rheumatoid arthritis prevalence in our subjects were each higher than reference rates.

Conclusion

This is the first evaluation of familial aggregation for SAPHO syndrome in a large cohort. SAPHO syndrome has a weak familial aggregation. There is a relatively high prevalence of coexisting autoimmune disease among patients with SAPHO syndrome and their first-degree relatives. These results would prompt physicians to screen SAPHO syndrome patients and their family members for concomitant autoimmune diseases.

Keypoints

This study suggesting a potential genetic component in the pathogenesis of SAPHO syndrome. This study is the first to evaluate the family aggregation of SAPHO syndrome in a large cohort.

Clinical features of myasthenia gravis with neurological and systemic autoimmune diseases

Multiple reports on the co-existence of autoimmune diseases and myasthenia gravis (MG) have raised considerable concern. Therefore, we reviewed autoimmune diseases in MG to explore their clinical presentations and determine whether the presence of autoimmune diseases affects the disease severity and treatment strategies for MG. We reviewed all the major immune-mediated coexisting autoimmune conditions associated with MG. PubMed, Embase and Web of Science were searched for relevant studies from their inception to January 2023. There is a higher frequency of concomitant autoimmune diseases in patients with MG than in the general population with a marked risk in women. Most autoimmune comorbidities are linked to AChR-MG; however, there are few reports of MuSK-MG. Thyroid disorders, systemic lupus erythematosus, and vitiligo are the most common system autoimmune diseases associated with MG. In addition, MG can coexist with neurological autoimmune diseases, such as neuromyelitis optica (NMO), inflammatory myopathy (IM), multiple sclerosis (MS), and autoimmune encephalitis (AE), with NMO being the most common. Autoimmune diseases appear to develop more often in early-onset MG (EOMG). MS coexists more commonly with EOMG, while IM coexists with LOMG. In addition, MG complicated by autoimmune diseases tends to have mild clinical manifestations, and the coexistence of autoimmune diseases does not influence the clinical course of MG. The clinical course of neurological autoimmune diseases is typically severe. Autoimmune diseases occur most often after MG or as a combined abnormality; therefore, timely thymectomy followed by immunotherapy could be effective. In addition, thymoma-associated AChR MG is associated with an increased risk of AE and IM, whereas NMO and MS are associated with thymic hyperplasia. The co-occurrence of MG and autoimmune diseases could be attributed to similar immunological mechanisms with different targets and common genetic factor predisposition. This review provides evidence of the association between MG and several comorbid autoimmune diseases.

The Pathological Activation of Microglia Is Modulated by Sexually Dimorphic Pathways

Microglia are the primary immunocompetent cells of the central nervous system (CNS). Their ability to survey, assess and respond to perturbations in their local environment is critical in their role of maintaining CNS homeostasis in health and disease. Microglia also have the capability of functioning in a heterogeneous manner depending on the nature of their local cues, as they can become activated on a spectrum from pro-inflammatory neurotoxic responses to anti-inflammatory protective responses. This review seeks to define the developmental and environmental cues that support microglial polarization towards these phenotypes, as well as discuss sexually dimorphic factors that can influence this process. Further, we describe a variety of CNS disorders including autoimmune disease, infection, and cancer that demonstrate disparities in disease severity or diagnosis rates between males and females, and posit that microglial sexual dimorphism underlies these differences. Understanding the mechanism behind differential CNS disease outcomes between men and women is crucial in the development of more effective targeted therapies.

Worldwide prevalence of neuromyelitis optica spectrum disorder (NMOSD) and neuromyelitis optica (NMO): a systematic review and meta-analysis

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a progressive demyelinating disease of the central nervous system that has overlapping symptoms with multiple sclerosis (MS) but differs from it in a variety of ways. Previous studies have reported conflicting results trying to estimate the number of individuals affected by them which is why we designed this systematic review and meta-analysis to estimate the worldwide prevalence and incidence of NMOSD/NMO based on current evidence.

METHODS

We searched PubMed, Scopus, EMBASE, Web of Science, and gray literature including references from the identified studies, review studies, and conference abstracts which were published up to February 1, 2022. We used all MeSH terms pertaining to "NMOSD," "NMO," and all the terms on "prevalence," "incidence," and "epidemiology" to identify the search components. Pooled effect sizes were measured using random-effect model by DerSimonian-Laird.

RESULTS

The prevalence and incidence rates of NMOSD/NMO ranged from 0.07 to 10 and 0.029 to 0.880 per 100,000 population, respectively. The overall pooled prevalence of NMO per 100,000 population was 1.54 (I²: 98.4%, 95% CI: 1.13-1.96, P< 0.001) based on the 2006 criteria, 1.51 (I²: 99.4%, 95% CI: 1.21-1.81, P < 0.001) based on the 2015 criteria and 2.16 (I²: 89.4%, 95% CI: 1.46-2.86, P < 0.001) based on the 2006/2015 criteria. The overall annual incidence of NMO per 100,000 population was 0.155 (I²: 95%, 95% CI: 0.115-0.195, P < 0.001) based on the 2006 criteria and 0.278 (I²: 100%, 95% CI: 0.135-0.420, P < 0.001) based on the 2015 criteria. The prevalence rates were highest in French West Indies and South Korea, and lowest in Cuba and Australia, based on the 2006 and 2015 criteria, respectively. Also, the highest annual incidence rates were obtained for Sweden and Slovak republic and the lowest for Cuba and Australia based on the 2006 and 2015 criteria, respectively. All estimated rates were higher among females compared to males.

CONCLUSION

Although rare, NMOSD/NMO impact affected individuals in devastating ways. Several large-scale prospective studies are required to reach a comprehension of the epidemiological aspects of these notorious demyelinating conditions.

The description of neuromyelitis optica spectrum disorder: Patient registry in Yangtze River Delta area of China

OBJECTIVE

To describe the clinical features of neuromyelitis optica spectrum disorder (NMOSD) through patient registry in Yangtze River Delta area of China.

METHODS

A total of 502 consecutive patients diagnosed with aquaporin-4 antibody (AQP4-ab)-positive NMOSD were registered between December 2018 to January 2021 in multiple tertiary referral centers within the framework of Yangtze River Delta of China. Their baseline data were reviewed, and follow-up clinical information were collected prospectively.

RESULTS

The mean age at onset was 37.3 (range 3-80 years) years and the female-to-male ratio was 8.1:1. The median disease duration was 47 months (interquartile range [IQR] 25-84 months). A total of 1372 attacks of the 502 patients were recorded till the last follow-up, with a median annualized relapse rate of 0.4 (IQR 0.3-0.6). Nearly one-fourth (24.5%, 336/1372) of the attacks had prodromic events, including upper respiratory tract infection (36.3%, 122/336), fever (20.2%, 68/336) and pregnancy-related issues (17.9%, 60/336), etc. Myelitis was the most common attack type throughout the disease course (51.4%, 705/1372), followed by optic neuritis (ON, 43.1%, 592/1372). As for onset phenotype, ON (37.3%, 187/502) prevailed over myelitis (28.3%, 142/502). The median time to first relapse was 12 months (IQR 5-25 months). Patients with brainstem encephalitis at onset were more likely to have other anatomical region involved in subsequent attacks (p < 0.001), compared to other onset type. The median serum AQP4-ab titer measured by cell-based assays was 1:100 (IQR 1:32-1:320, range 1:10-1:10,000). The baseline AQP4-ab titer in cerebrospinal fluid (r = 0.542, p <0.001), overall ARR (r = 0.232, p< 0.001) and the EDSS scores at last follow-up (r = 0.119, p = 0.022) significantly correlated with baseline serum AQP4-ab titer. Antinuclear antibodies (48.4%), thyroid peroxidase antibodies (30.7%), and anti-SSA antibodies (26.2%) represented the most frequent concomitant antibodies, while autoimmune thyroid disorders (13.1%, 66/502) and Sjogren's syndrome (10.8%, 54/502) were the most common accompanying autoimmune diseases. Till the last follow-up, 403 patients received preventive treatments. Azathioprine represented the most common initial treatment, mycophenolate mofetil and rituximab was the most common second and third-line treatment, respectively. The EDSS score at the last follow-up ranged from 0 to 8.5 with a median of 2 (IQR 1-3).

CONCLUSIONS

A comprehensive clinical picture of patients with AQP4-ab-positive NMOSD in Yangtze River Delta area of China was presented. More information on disease tragedy and predictive prognostic factors could be generated through long-term observations.

Neuromyelitis Optica Spectrum Disorders in North Indian Population: Experience from a Tertiary Care Center

Introduction

To understand neuromyelitis optica spectrum disorders (NMOSDs) better we need to study them in different populations. This prospective study was conducted to characterize clinical, serological, radiological, and therapeutic profile of NMOSDs in a North Indian population.

Materials and Methods

This study included 81 patients with NMOSDs. All patients underwent detailed history and examinations and were followed at 3 monthly intervals. They were evaluated using standard investigations including gadolinium-enhanced magnetic resonance imaging (MRI) of the brain and spine with thin section optic nerve cuts and treated as per the standard guidelines. Data were recorded meticulously.

Results

The mean age was 33.7 ± 13.4 years. The mean age at disease onset was 31.2 ± 13.5 years. Female-to-male ratio was 1.9:1. About 32.1% of patients presented with optic neuritis (ON), 56.8% with transverse myelitis (TM), and 11.1% with both ON and TM. The mean time from disease onset to diagnosis was 16.17 ± 23.09 months. Muscle atrophy, Lhermitte symptom, and tonic spasms were common. Foster-Kennedy syndrome-like presentation was seen in 8.6%. NMO antibodies were positive in 41 patients. MRI revealed involvement of <4 vertebral segments in 16.4% of patients with TM. Patients were managed as per standard guidelines. The mean follow-up duration was 15.3 ± 6 months. Approximately 88.9% had good functional outcome.

Conclusion

NMOSDs are a common cause of demyelinating illnesses in Northern India. The response to treatment is excellent and most patients recover without residual disability.

Sera of Neuromyelitis Optica Patients Increase BID-Mediated Apoptosis in Astrocytes

Neuromyelitis optica (NMO) is a rare disease usually presenting with bilateral or unilateral optic neuritis with simultaneous or sequential transverse myelitis. Autoantibodies directed against aquaporin-4 (AQP4-IgG) are found in most patients. They are believed to cross the blood−brain barrier, target astrocytes, activate complement, and eventually lead to astrocyte destruction, demyelination, and axonal damage. However, it is still not clear what the primary pathological event is. We hypothesize that the interaction of AQP4-IgG and astrocytes leads to DNA damage and apoptosis. We studied the effect of sera from seropositive NMO patients and healthy controls (HCs) on astrocytes’ immune gene expression and viability. We found that sera from seropositive NMO patients led to higher expression of apoptosis-related genes, including BH3-interacting domain death agonist (BID), which is the most significant differentiating gene (p < 0.0001), and triggered more apoptosis in astrocytes compared to sera from HCs. Furthermore, NMO sera increased DNA damage and led to a higher expression of immunological genes that interact with BID (TLR4 and NOD-1). Our findings suggest that sera of seropositive NMO patients might cause astrocytic DNA damage and apoptosis. It may be one of the mechanisms implicated in the primary pathological event in NMO and provide new avenues for therapeutic intervention.

Factors Influencing Social Participation Among Persons With Neuromyelitis Optica Spectrum Disorders: A Cross-Sectional Study

Background

Neuromyelitis optica spectrum disorders seriously hinder social participation. Only clarifying the status of social participation and the factors most strongly influencing it can promote better-targeted support for those with neuromyelitis optica spectrum disorders.

Objectives

To explore the factors influencing social participation among persons with neuromyelitis optica spectrum disorders.

Methods

138 persons with neuromyelitis optica were recruited by convenience sampling. They completed the Impact on Participation and Autonomy Questionnaire, and were rated using the Barthel index, the Beck Anxiety Inventory and the Beck Depression Inventory. The data were used to evaluate a generalized linear model predicting social participation.

Results

The respondents mostly perceived good or very good possibilities of social participation, but participation outdoors and in social relations were considered more restricted. Ability in the activities of daily living, education level, bladder and bowel dysfunction, and depression were four significant predictors of social participation.

Conclusions

Strengthening training in the activities of daily living, continuing education, giving positive psychological support and helping with bladder and bowel problems may help to promote social participation among those with neuromyelitis optica spectrum disorders.

Correlation between Amerindian ancestry and neuromyelitis optica spectrum disorders (NMSOD) among patients in Midwestern Brazil

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is the second most frequently demyelinating, autoimmune, and inflammatory Central Nervous System (CNS) disease, and its prevalence varies greatly according to geography and ethnicity.

OBJECTIVE

To determine the prevalence and phenotype of NMOSD at a reference center for demyelinating diseases in Goiás State.

METHODS

This was a cross-sectional study, approved under CAAE number 8380.9317.9.0000.5078. All patients fulfilled the 2015 international consensus criteria.

RESULTS

Our study showed NMOSD as 9.37% of all demyelinating diseases registered in. It occurred predominantly in women (81%) and non-white individuals (83.4% had self-declared mixed skin color), and the median age at onset was 48 years. Amerindian ancestry was significantly higher (68.75%) than others. Longitudinally extensive transverse myelitis (LETM) alone ≥3 vertebral segments (35%) and optic neuritis (ON) alone (35%) were the most common onset manifestations. The median length of time from disease beginning to study enrollment was 48 months. A relapsing course and moderate disability (Expanded Disability Status Scale (EDSS) 3.0-4.0) were most commonly observed. The worst neurological impairments, characterized by EDSS>4.5, occurred more frequently in males (44.5% among men versus 20.5% among women). The majority of the patients had been receiving immunosuppressive treatment with azathioprine since the diagnosis of NMSOD: 77% (37) had a good therapeutic response. The prevalent outcome (84%) was permanent disability: 52% became physically handicapped; 54% had permanent visual impairment (25% with bilateral and 75% with unilateral amaurosis) and 30% had sphincter disability (82% with neurogenic bladder and 18% with ostomy).

CONCLUSION

The estimated prevalence of NMOSD in Goiás is 0.79/per 100,000 inhabitants. The predominant phenotype comprises women, non-whites, onset in the fourth decade of life, relapsing course, and permanent moderate disability. Our study was the first on the epidemiology of NMOSD in Goiás, where NMOSD predominantly correlates with Amerindian ancestry.

Clinical and prognostic aspects of patients with the Neuromyelitis Optica Spectrum Disorder (NMOSD) from a cohort in Northeast Brazil

Introduction

Neuromyelitis optica spectrum disorders (NMOSD) is a rare inflammatory and demyelinating disease of the central nervous system (CNS) more frequent in women and Afro-descendants. No previous epidemiological or prognostic study has been conducted in the region of the state of Bahia, Brazilian Northeast.

Objective

To evaluate clinical and prognostic aspects in patients with NMOSD from a cohort in northeastern Brazil.

Material and methods

A single-center retrospective study was conducted with consecutive patients diagnosed with NMOSD. Clinical and epidemiological characteristics were described. The degree of disability was expressed by the Expanded Disability Status Scale (EDSS). Worsening disability were analyzed through negative binomial regression adjusted for disease duration.

Results

Ninety-one patients were included, 72 (79.1%) female and 67 (73.6%) afro descendants. Mean age at onset was 36 (± 14) years and 73.3% were anti-aquaporin-4 antibody positive. Isolated transverse myelitis (32.9%) and isolated optic neuritis (22.4%) were the most frequent initial clinical syndromes. After multivariate analysis, optic neuritis (RR = 0.45; 95% CI = 0.23 – 0.88; p = 0.020) and dyslipidemia (RR = 0.40; 95% CI = 0.20 – 0.83; p = 0.014) were associated with slower disease progression. Area postrema involvement (RR = 6.70; 95% CI = 3.31 – 13.54; p < 0.001) and age at onset (RR = 1.03; 95% CI = 1.01 – 1.05; p = 0.003) were associated with faster disease progression.

Conclusions

In the first clinical and prognostic study in northeastern Brazil, we identified area postrema involvement, age at onset, optic neuritis at fist syndrome and dyslipidemia as the main prognostic factors associated with disease progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02621-5.

• Isolated transverse myelitis was the most frequent initial clinical syndrome.

• Optic neuritis as first clinical syndrome was independently associated with better prognostic.

• Age at onset were associated with faster disease progression.

• Hashimoto's thyroiditis was the most frequent autoimmune disease in NMOSD.

Vaccination in neuromyelitis optica spectrum disorders: Friend or enemy?

Neuromyelitis optica spectrum disorders (NMOSDs) are uncommon antibody-mediated autoimmune diseases of the central nervous system (CNS), mainly occurring in optic nerves and spinal cord, which can cause visual impairment, paralysis, and occasionally bulbar dysfunction. Such neurological deficits can adversely affect pulmonary functions and increase complicated infection risk. Besides, most NMOSD patients undergo immunosuppressive therapy. All these factors make NMOSD patients the potential high-risk group under the current pandemic of coronavirus disease 2019 (COVID-19). Meanwhile, COVID-19 infection has already been demonstrated as a risk factor for NMOSD relapses. This review discusses the basic immunology of vaccination and common problems, including immunogenicity, safety, and efficacy of vaccination on NMOSD patients. Additionally, we offered vaccination recommendations, health care and treatment advice for NMOSD patients under the background of COVID-19.

Pathobiology, Diagnosis, and Current Biomarkers in Neuromyelitis Optica Spectrum Disorders

Background

Neuromyelitis optica spectrum disorder (NMOSD) is characterized by chronic inflammation of the central nervous system (CNS), particularly the optic nerves and spinal cord. Although it displays some clinical features similar to multiple sclerosis (MS), the etiology and treatment are distinct, and therefore accurate diagnosis is essential. Autoantibodies targeting the water channel protein aquaporin-4 (AQP4) and the myelin sheath protein myelin oligodendrocyte glycoprotein are the major antigen-specific serological biomarkers known to date, with destruction of astrocytes as the primary mode of CNS damage in AQP4-positive disease.

Content

This mini-review summarizes the pathobiology, clinical features, and current methods of serological testing used to assess NMOSD and differentiate this disorder from MS. A brief summary of emerging therapies is also presented.

Summary

NMOSD can be distinguished from MS through a combination of clinical findings, imaging investigations, and serological analysis. Seronegative cases are particularly difficult to diagnose and can pose a challenge to clinicians. As knowledge deepens, new therapies and biomarkers are expected to improve treatment of this rare debilitating disease.

Imaging features to distinguish AQP4-positive NMOSD and MS at disease onset: A retrospective analysis in a single-center cohort

PURPOSE

To compare the diagnostic performance of imaging criteria that differentiate AQP4⁺ Neuromyelitis Optica Spectrum Disorders (NMOSD) and Multiple Sclerosis (MS) at disease onset (DO) and follow-up (FU).

METHODS

We retrospectively analyzed MRI scans at DO (defined as the first 60 days of patient-reported symptom onset) in 10 AQP4⁺NMOSD and 25 (time to MRI matched) relapsing-remitting MS patients from a monocentric cohort.

RESULTS

The Matthews criteria were met in 20% of AQP4⁺NMOSD patients at DO vs. 33% at FU, and in 96% of RRMS patients vs.100% at FU. Specificity (SP) and sensitivity (SE) were thus high at both time-points: SP-DO: 96%; SP-FU:100%; and SE-DO: 80%; SE-FU: 67%, with similar area under the curve (AUC) values at DO: 88% [95% CI 74%-100%] and FU: 83% [95% CI 67%-100%]. The Cacciaguerra criteria were met in 90% of AQP4⁺NMOSD patients at DO vs. 88.9% at FU and in 24% of RRMS patients vs. 14% at FU; SP-DO: 87%; SP-FU: 86%; and SE-DO: 90%; SE-FU: 89%, with similar AUC values at DO: 88% [95% CI 76%-98%] and FU: 87% [95% CI 74%-98%].

CONCLUSIONS

While diagnostic MRI criteria were developed on data acquired years after disease onset, our study demonstrates their high applicability at the earliest disease stages, thus emphasising their valuable use in clinical practice.

[Clinical and epidemiological aspects of neuromyelitis optic spectrum diseases in the russian population]

OBJECTIVE

To present clinical and epidemiological aspects of neuromyelitis optica spectrum disorders (NMOSD) in the Russian Federation.

MATERIAL AND METHODS

We studied 142 patients who met diagnostic criteria of 2015 for NMOSD. Sex, age at disease onset, presence or absence of aquaporin-4 immunoglobulin G antibodies (AQP4-IgG), mail clinical symptoms, oligoclonal IgG, therapy for the treatment of exacerbations and prevention of exacerbations, compliance with 2006 diagnostic criteria were assessed.

RESULTS

The prevalence of women is 4.26:1, the most frequent age at disease onset is 18-29 years (36% of cases). The laboratory aspects of the disease are characterized and approaches to the treatment and prevention of exacerbations of NMOSD in patients of the Russian population are evaluated. Approaches to diagnostics are compared depending on the applied diagnostic criteria (34% of patients do not meet neuromyelitis optica 2006 diagnostic criteria). A prognosis for the prevalence of NMOSD in the Russian population has been proposed: 0.45-4.21/100000.

CONCLUSION

This is the first published data on clinical and epidemiological characteristics of NMOSD in the Russian Federation.

[Epidemiology of neuromyelitis optica spectrum disorder]

Neuromyelitis optica spectrum disorder (NMOSD) is a group of rare and mostly severe autoimmune demyelinating central nervous system disorders which prevalence is 0.7-1 per 100.000 population and incidence is 0.037-0.73 per 100.000 person-years. NMOSD may present as a combination of uni- or bilateral optic neuritis, transverse myelitis or lesions of brain stem and other brain regions. The symptoms are mostly relapsing (up to 97.5%) and progressive. Occurrence of relapses is associated with seropositivity for aquaporin-4 (up to 80% of NMOSD patients) and bears a less favorable prognosis (mortality up to 32%). Women seropositive for aquaporin 4 constitute 90% of NMOSD patients. Compared to other demyelinating disorders, NMOSD is characterized by late onset (mean age is about 39 years) and association with other autoimmune disorders, including systemic lupus erythematosus, myasthenia gravis and Sjogren's syndrome. A genetic predisposition was found among Blacks and Asians, with HLA-DRB1*03:01 gene associated with higher risk of NMOSD in Asians. The course of the disease tends to be more severe in Blacks. There are clusters of an increased incidence of NMOSD in the Carribeans and in the Far East. Continued increase of prevalence and incidence of NMOSD worldwide compels continued epidemiological research in order to provide early diagnosis and treatment for this disorder.

An Experimental Model of Neuromyelitis Optica Spectrum Disorder-Optic Neuritis: Insights Into Disease Mechanisms

Background: Optic neuritis (ON) is a common inflammatory optic neuropathy, which often occurs in neuromyelitis optica spectrum disease (NMOSD). An experimental model of NMOSD-ON may provide insight into disease mechanisms.

Objective: To examine the pathogenicity of autoantibodies targeting the astrocyte water channel aquaporin-4 [aquaporin-4 (AQP4)-immunoglobulin G (AQP4-IgG)] in the optic nerve.

Materials and Methods: Purified IgG from an AQP4-IgG-positive NMOSD-ON patient was together with human complement (C) given to wild-type (WT) and type I interferon (IFN) receptor-deficient mice (IFNAR1-KO) as two consecutive intrathecal injections into cerebrospinal fluid via cisterna magna. The optic nerves were isolated, embedded in paraffin, cut for histological examination, and scored semi-quantitatively in a blinded fashion. In addition, optic nerves were processed to determine selected gene expression by quantitative real-time PCR.

Results: Intrathecal injection of AQP4-IgG+C induced astrocyte pathology in the optic nerve with loss of staining for AQP4 and glial fibrillary acidic protein (GFAP), deposition of C, and demyelination, as well as upregulation of gene expression for interferon regulatory factor-7 (IRF7) and CXCL10. Such pathology was not seen in IFNAR1-KO mice nor in control mice.

Conclusion: We describe induction of ON in an animal model for NMOSD and show a requirement for type I IFN signaling in the disease process.

Status of the neuromyelitis optica spectrum disorder in Latin America

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) is an increasing diagnostic and therapeutic challenge in Latin America (LATAM). Despite the heterogeneity of this population, ethnic and socioeconomic commonalities exist, and epidemiologic studies from the region have had a limited geographic and population outreach. Identification of some aspects from the entire region are lacking.

OBJECTIVES

To determine ethnic, clinical characteristics, and utilization of diagnostic tools and types of therapy for patients with NMOSD in the entire Latin American region.

METHODS

The Latin American Committee for Treatment and Research in MS (LACTRIMS) created an exploratory investigational survey addressed by Invitation to NMOSD Latin American experts identified through diverse sources. Data input closed after 30 days from the initial invitation. The questionnaire allowed use of absolute numbers or percentages. Multiple option responses covering 25 themes included definition of type of practice; number of NMOSD cases; ethnicity; utilization of the 2015 International Panel criteria for the diagnosis of Neuromyelitis optica (IPDN); clinical phenotypes; methodology utilized for determination of anti-Aquaporin-4 (anti- AQP4) antibodies serological testing, and if this was performed locally or processed abroad; treatment of relapses, and long-term management were surveyed.

RESULTS

We identified 62 investigators from 21 countries reporting information from 2154 patients (utilizing the IPDN criteria in 93.9% of cases), which were categorized in two geographical regions: North-Central, including the Caribbean (NCC), and South America (SA). Ethnic identification disclosed Mestizos 61.4% as the main group. The most common presenting symptoms were concomitant presence of optic neuritis and transverse myelitis in 31.8% (p=0.95); only optic neuritis in 31.4% (more common in SA), p<0.001); involvement of the area postrema occurred in 21.5% and brain stem in 8.3%, both were more frequent in the South American cases (p<0.001). Anti-AQP4 antibodies were positive in 63.9% and anti-Myelin Oligodendrocyte Glycoprotein (MOG) antibodies in 4.8% of total cases. The specific laboratorial method employed was not known by 23.8% of the investigators. Acute relapses were identified in 81.6% of cases, and were treated in 93.9% of them with intravenous steroids (IVS); 62.1% with plasma exchange (PE), and 40.9% with intravenous immunoglobulin-G (IVIG). Therapy was escalated in some cases due to suboptimal initial response. Respondents favored Rituximab as long-term therapy (86.3%), whereas azathioprine was also utilized on 81.8% of the cases, either agent used indistinctly by the investigators according to treatment accessibility or clinical judgement. There were no differences among the geographic regions.

CONCLUSIONS

This is the first study including all countries of LATAM and the largest cohort reported from a multinational specific world area. Ethnic distributions and phenotypic features of the disease in the region, challenges in access to diagnostic tools and therapy were identified. The Latin American neurological community should play a determinant role encouraging and advising local institutions and health officials in the availability of more sensitive and modern diagnostic methodology, in facilitating the the access to licensed medications for NMOSD, and addressing concerns on education, diagnosis and management of the disease in the community.

Mortality of neuromyelitis optica spectrum disorders in a Chinese population

Objective

Neuromyelitis optica spectrum disorder (NMOSD) is a rapidly disabling disease. Epidemiologic studies have suggested varying NMOSD mortality across ethnic groups. However, NMOSD mortality data in China are scarce. This study’s objectives were to explore mortality and causes of death among Chinese NMOSD patients and to identify independent predictors of death.

Methods

We performed a retrospective study with a 10‐year follow‐up of Chinese NMOSD patients. A Cox proportional hazards model was used to identify independent predictors of death.

Results

Five hundred and sixty‐nine patients were included; 24 patients died during follow‐up, for overall mortality of 4.2%. In these patients, the median disease duration at the time of death was 3.4 years. The most common cause of death was secondary infection (62.5%), especially respiratory infection (45.8%). The second most common cause of death was extensive cervical myelitis with respiratory failure (16.7%). Other causes included suicide (8.3%), cancer (4.2%), cerebral embolism (4.2%), and unknown causes (4.2%). The multivariate Cox analyses indicated that a short first interattack interval (HR = 0.93, 95% CI 0.89–0.98, p = 0.003), lack of regular immunotherapy (HR = 10.34, 95% CI 4.05–26.37, p < 0.001), and older age at onset were independent predictors of death. Every increasing decade of onset age increased the risk of death 2.59 times (95% CI 1.74–3.86, p < 0.001).

Interpretation

Infections were more common in patients not treated with any immunotherapy, indicating that early and consequent immunotherapy might prevent death by infections, which is of great importance for further treatment of NMOSD patients to avoid undertreatment due to fear of treatment‐associated infections.

The aquaporin4-IgG status and how it affects the clinical features and treatment response in NMOSD patients in Egypt

Background

In Egypt, the characterization of Neuromyelitis Optica Spectrum Disorder (NMOSD) is lacking.

Objectives

To determine the demographics, clinical features, aquaporin4 antibodies (AQP4-IgG) status, and neuroimaging of Egyptian NMOSD patients.

Methods

Retrospective analysis of 70 NMOSD patients’ records from the MS clinic, Kasr Alainy hospital, between January 2013 and June 2018.

Results

Patients’ mean age was 34.9 ± 9.2 years, and the mean at disease onset was 28.9 ± 10.5 years. Fifty-nine patients had an initial monosymptomatic presentation. AQP4-IgG was measured using either enzyme-linked immunosorbent assay (ELISA) (22 patients) or cell-based assay (CBA) (34 patients). Six and 29 patients had positive results, respectively (p < 0.001). 84% had typical NMOSD brain lesions. Longitudinally extensive myelitis was detected in 49 patients, and 9 had either short segments or normal cords. Treatment failure was higher in seropositive patients. Rituximab significantly reduced the annualized relapse rate (ARR) compared to Azathioprine with a percentage reduction of (76.47 ± 13.28) and (10.21 ± 96.07), respectively (p = 0.04). Age at disease onset was the only independent predictor for disability (p < 0.01).

Conclusion

Treatment failure was higher in seropositive patients. However, there was no difference in clinical or radiological parameters between seropositive and seronegative patients. Patients, who are polysymptomatic or with older age of onset, are predicted to have higher future disability regardless of the AQP4-IgG status.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02083-1.

Prevalence of neuromyelitis optica spectrum disorder in Belo Horizonte, Southeast Brazil

BACKGROUND

Studies on the prevalence of neuromyelitis optica spectrum disorder (NMOSD) are still scarce. The aim of the current study was to determine the prevalence rate of NMOSD in Belo Horizonte, southeast Brazil, where the prevalence rate of multiple sclerosis (MS) has already been established.

METHODS

For this observational study, eligible patients had to meet the 2015 International Panel for Neuromyelitis Optica Diagnosis, be seen at the study center between January 2000 and February 2019 and live in Belo Horizonte. The prevalence rate of NMOSD was estimated based on the number of MS and NMOSD patients seen at same Center during the same period, and the previously established prevalence of MS in Belo Horizonte.

RESULTS

During the study period, there were 69 patients with NMOSD, 60 (87.0%) of whom were females, and 44 (63.8%) non-whites. The median age at disease onset was 36.7 (4-72) years, the mean EDSS score 4.78±2.36, and the mean ARR 0.57±0.43. Anti-aquaporin-4 immunoglobulin testing was available for 61 (88.4%) patients, of whom 41 (67.2%) had a positive result. During the same period, 280 MS patients were seen. Considering the local known prevalence rate of MS of 18.1/100,000 inhabitants, the estimated NMOSD prevalence rate in Belo Horizonte was 4.52/100,000 (95% CI 3.72-5.43) inhabitants.

CONCLUSION

The prevalence rate of NMOSD in Belo Horizonte is high as compared with those found in most of the studies reported to date.

Worldwide Incidence and Prevalence of Neuromyelitis Optica: A Systematic Review

Objective

Since the last epidemiologic review of neuromyelitis optica/neuromyelitis optica spectrum disorder (NMO/NMOSD), 22 additional studies have been conducted. We systematically review the worldwide prevalence, incidence, and basic demographic characteristics of NMOSD and provide a critical overview of studies.

Methods

PubMed, Ovid MEDLINE, and Embase using Medical Subject Headings and keyword search terms and reference lists of retrieved articles were searched from 1999 until August 2019. We collected data on the country; region; methods of case assessment and aquaporin-4 antibody (AQP4-Ab) test; study period; limitations; incidence (per 100,000 person-years); prevalence (per 100,000 persons); and age-, sex-, and ethnic group–specific incidence or prevalence.

Results

We identified 33 relevant articles. The results indicated the highest estimates of incidence and prevalence of NMOSD in Afro-Caribbean region (0.73/100 000 person-years [95% CI: 0.45–1.01] and 10/100 000 persons [95% CI: 6.8–13.2]). The lowest incidence and prevalence of NMOSD were found in Australia and New Zealand (0.037/100 000 person-years [95% CI: 0.036–0.038] and 0.7/100,000 persons [95% CI: 0.66–0.74]). There was prominent female predominance in adults and the AQP4-Ab–seropositive subpopulation. The incidence and prevalence peaked in middle-aged adults. African ethnicity had the highest incidence and prevalence of NMOSD, whereas White ethnicity had the lowest. No remarkable trend of incidence was described over time.

Conclusion

NMOSD is a rare disease worldwide. Variations in prevalence and incidence have been described among different geographic areas and ethnicities. These are only partially explained by different study methods and NMO/NMOSD definitions, highlighting the need for specifically designed epidemiologic studies to identify genetic effects and etiologic factors.

Different alteration patterns of sub-macular choroidal thicknesses in aquaporin-4 immunoglobulin G antibodies sero-positive neuromyelitis optica spectrum diseases and isolated optic neuritis

PURPOSE

The ocular choroid is a sensitive biomarker of vascular perfusion in optic neuritis (ON) patients due to its vascular structures. The purpose of this study was to evaluate alterations in sub-macular choroidal thicknesses (sub-MCT) in aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) sero-positive neuromyelitis optica spectrum disease (AQP4-IgG+/NMOSD) and isolated ON (ION) patients using optical coherence tomography (OCT).

METHODS

A total of 208 ON patients (275 eyes) and healthy controls (HCs) who underwent sub-MCT and retinal microstructure detection with OCT were enrolled in this study.

RESULTS

Among all the ON patients, 102 (49.0%) cases were identified as serum AQP4-IgG-positive, with 106 (51.0%) cases being negative, excluding multiple sclerosis as the ION cohort. The sub-MCT in the AQP4-IgG+/NMOSD patients decreased in 0-6 months after ON attacks. However, for the ION cohort, the sub-MCT decreased in 0-2 months and then stayed normal or slightly increased in 2-4 months after the first ON attack, finally sharply decreasing after 6 months. For unilateral AQP4-IgG+/NMOSD patients, eyes without ON also presented retinal layer thinning and sub-MCT slight reduction independent of ON attacks.

CONCLUSIONS

The sub-MCT in AQP4-IgG+/NMOSD patients were reduced at all stages of ON, which distinguished the ION patients as decreasing only at chronic stage of ON. It implied that ocular vascular hypoperfusion plays a potential role in ON pathogenesis and the different patterns could be caused by the distinct pathogenesis of AQP4-IgG+/NMOSD and ION.

Epidemiological findings of neuromyelitis optica spectrum disorders in a Venezuelan study

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD), is a rare autoimmune inflammatory disease of the central nervous system. Since the countries of Latin America (LATAM) show contrast in geographic, social, environmental factors, and genetic heterogeneity, the information about NMOSD epidemiology in the region allows a better understanding of the disease and its clinical outcome.

OBJECTIVES

To determine the prevalence, relative frequency (RF), and clinical characteristics of NMOSD in a multiethnic Venezuelan cohort of patients with demyelinating disorders.

METHODS

We conducted a retrospective descriptive multicenter study of hospital case records of individuals with an established diagnosis of MS and NMOSD in the National Program for Multiple sclerosis (MS) from 2011 to 2018. We selected those NMOSD cases based on the 2006 Wingerchuck and the 2015 International panel for the diagnosis of Neuromyelitis optica (IPND) criteria.

RESULTS

We identified 249 patients with NMOSD. The prevalence was 2.11 per100,000 individuals (95% confidence interval (CI)1.85 2.37), the RF was 23%, and the MS/NMOSD ratio was 3.2:1. The average disease onset occurred by the fourth decade of life (34±14.8 years of age); with a strong female predominance (female to male ratio: 4:1). Mestizos constituted 86,7% of this cohort. Most of the patients presented initially with simultaneous optic neuritis (ON) and acute transverse myelitis (ATM) and a recurrent course was registered in 82.3% of cases. The mean of the expanded disability status scale (EDSS) was 3.5 (IQR 2-7). Abnormal brain and spine MRI were present in 47.8% and 81.1% of patients, respectively. Antibodies against aquaporin-4 (AQP4) which were measured through a cell-based assay were positive in 55.3% of the individuals tested. The most used immunosuppressant agent was Azathioprine (57.4%).

CONCLUSION

NMOSD in Venezuela affects mainly young Mestizo women and shows one of the highest relative frequency in the region. Planning and developing healthcare programs for underserved populations as well as more comprehensive LATAM studies are required to identify the distribution and variations of its epidemiological picture.

Autologous hematopoietic stem-cell transplantation in neurological disorders: current approach and future directions

INTRODUCTION

Autologous hematopoietic stem-cell transplantation (AHSCT) has become increasingly popular in recent years as an effective treatment of immune-mediated neurological diseases. Treatment-related mortality has significantly reduced primarily through better patient selection, optimization of transplant technique, and increased center experience.

AREA COVERED

Multiple sclerosis is the main indication, but people with neuromyelitis optica spectrum disorder, stiff-person spectrum disorder, chronic inflammatory demyelinating polyneuropathy, myasthenia gravis, and other immune-mediated neurological disorders also have been treated. The review herein discusses the use of AHSCT in these neurological disorders, the importance of patient selection and transplant technique optimization and future directions.

EXPERT OPINION

Phase II and III clinical trials have confirmed the safety and efficacy of AHSCT in multiple sclerosis and recent phase II clinical trials have also suggested its safety and efficacy in chronic inflammatory demyelinating polyneuropathy and neuromyelitis optica spectrum disorder, with the evidence in other neurological disorders limited to individual case reports, small case series, and registry data. Therefore, further randomized controlled clinical trials are required to assess its safety and efficacy in other neurological conditions. However, in rare neurological conditions, pragmatic treatment trials or registry-based studies may be more realistic options for gathering efficacy and safety data.

An update on epidemiology, diagnosis & management of NMO-SD in the tertiary neurology department of Marrakech (Morocco)

INTRODUCTION

Neuromyelitis optica (NMO) and NMO spectrum disorders (NMO-SD) are inflammatory demyelinating diseases of the central nervous system. There are few epidemiological studies devoted to NMO, especially in Africa and the Middle East, but individual cases and series have been reported from many countries across the African continent.

OBJECTIVES

To describe the epidemiology, diagnosis, and management of NMO patients followed at the Mohammed VI University Hospital of Marrakech.

PATIENTS AND METHODS

This was a hospital-based retrospective study of 52 patients with NMO diagnosed and followed at the Neurology department of the University Hospital of Marrakech from 2004 to July 2019. The 2006 diagnostic criteria of NMOSD were used for patients admitted before 2015 for inflammatory disease of the central nervous system and the 2015 diagnostic criteria of NMO-SD for all patients thereafter. Collected data were analysed using SPSS software.

RESULTS

The study concerned 52 patients, 18 males and 34 females. Median age at disease onset was 32.5 years (range 7-55). Mean time between symptom onset and diagnosis of NMO was nine months 18 days (range 7 days to 4 years). In most patients, manifestations included visual acuity, tetraparesis, and sensorial disorders. Refractory vomiting and hiccup were noted in the first attack in 19% of patients. Two patients had hypersomnia and polyphagia, and one had been treated for depression ten months before the development of severe tetraplegia. Magnetic resonance imaging did not show any brain lesions in 29% of patients. Cervical myelitis extending to more than three vertebrae was found in 60% of patients. AQP4-antibody assay was performed only in 57.7% of patients, and was positive in 38.4%; anti-MOG was positive in four anti-AQP4 seronegative patients. Management strategies for NMO-SD included methylprednisolone pulses (70% of patients), plasmapheresis (25%), and rituximab (since 2017) for 46%. Outcome was favourable in 40% of patients and has remained stable in 50% of them.

CONCLUSION

Anti-NMO assays, made available during the last five years with the help of The Guthy-Jackson Charitable Foundation, have led to a clear jump in the number of cases diagnosed. Major advances in the field of epidemiology, imaging, and pathophysiology of NMO-SD have led to improved patient care and outcome.

Familial clustering of neuromyelitis optica and multiple sclerosis: clues pointing towards shared risks?

We examine the prevalence of the familial association of concordant NMOSD/NMOSD and discordant NMOSD/MS cases among a large NMOSD cohort. Familial association was examined in a monocenter cohort of 119 NMOSD patients and 45 patients at high risk of NMOSD from French West Indies. Data mining gathered 31 multiplex families. Twin monozygotic sisters concordant for NMOSD/NMOSD, and four discordant NMOSD/MS families, accounted respectively for 0.8% and 3.4% of the NMOSD cohort. Familial clustering was more frequent than random association. In discordant NMOSD/MS families, the NMOSD patient was always from the parental generation. The non-random successive familial cases of NMOSD and MS suggest a change of risk factor over generations.

Evaluation of retinal nerve fiber layer thickness and optic nerve functions in fellow eye of neuromyelitis optica with unilateral optic neuritis

Purpose

Peripapillary retinal nerve fibre layer (RNFL) thickness might be useful in monitoring ongoing subclinical structural damage especially in eyes with no history of optic neuritis (ON) in neuromyelitis optica (NMO).

Objective

To evaluate the peripapillary RNFL thickness and optic nerve functions in fellow eye of NMO with unilateral optic neuritis.

Materials and Methods

A comparative cross-sectional study was conducted in 2 tertiary hospitals from August 2017 to May 2019. RNFL thickness and optic nerve functions were evaluated. Statistical analysis was performed using Statistical Package for Social Science version 24.

Results

A total of 26 NMO patients and 26 controls were involved in this study. The median age (IQR) of NMO patients was 32.5 (12) years old. The RNFL thickness was significantly reduced in NMO patients with non-ON eyes as compared to control group. Best corrected visual acuity between the 2 groups were comparable (0.20 vs 0.00, p=0.071). Contrast sensitivity was also reduced in NMO patients (non-ON eyes) at all 5 spatial frequencies. In NMO group, 34.6% have normal colour vision. The mean deviation (MD) of Humphrey visual field (HVF) was higher in NMO group (p<0.001). There was a moderate correlation between RNFL thickness and contrast sensitivity. Weak correlation was found between the RNFL thickness with visual acuity and mean deviation of visual field test.

Conclusion

Our study showed that the fellow eye of NMO patients with unilateral ON revealed a significant reduction in RNFL thickness and all the optic nerve functions have subtle early changes that signify a subclinical retinal damage.

Epidemiology of Neuromyelitis Optica Spectrum Disorder and Its Prevalence and Incidence Worldwide

Neuromyelitis optica spectrum disorder (NMOSD) is an uncommon inflammatory disease of the central nervous system, manifesting clinically as optic neuritis, myelitis, and certain brain and brainstem syndromes. Cases clinically diagnosed as NMOSD may include aquaporin 4 (AQP4)-antibody-seropositive autoimmune astrocytopathic disease, myelin oligodendrocyte glycoprotein (MOG)-antibody-seropositive inflammatory demyelinating disease, and double-seronegative disease. AQP4-antibody disease has a high female-to-male ratio (up to 9:1), and its mean age at onset of ~40 years is later than that seen in multiple sclerosis. For MOG-antibody disease, its gender ratio is closer to 1:1, and it is more common in children than in adults. Its clinical phenotypes differ but overlap with those of AQP4-antibody disease and include acute disseminated encephalomyelitis, brainstem and cerebral cortical encephalitis, as well as optic neuritis and myelitis. Double-seronegative disease requires further research and clarification. Population-based studies over the past two decades report the prevalence and incidence of NMOSD in different populations worldwide. One relevant finding is the varying prevalence observed in different racial groups. Consistently, the prevalence of NMOSD among Whites is ~1/100,000 population, with an annual incidence of <1/million population. Among East Asians, the prevalence is higher, at ~3.5/100,000 population, while the prevalence in Blacks may be up to 10/100,000 population. For MOG-antibody disease, hospital-based studies largely do not observe any significant racial preponderance so far. This disorder comprises a significant proportion of NMOSD cases that are AQP4-antibody-seronegative. A recent Dutch nationwide study reported the annual incidence of MOG-antibody disease as 1.6/million population (adult: 1.3/million, children: 3.1/million). Clinical and radiological differences between AQP4-antibody and MOG-antibody associated diseases have led to interest in the revisions of NMOSD definition and expanded stratification based on detection of a specific autoantibody biomarker. More population-based studies in different geographical regions and racial groups will be useful to further inform the prevalence and incidence of NMOSD and their antibody-specific subgroups. Accessibility to AQP4-antibody and MOG-antibody testing, which is limited in many centers, is a challenge to overcome. Environmental and genetic studies will be useful accompaniments to identify other potential pathogenetic factors and specific biomarkers in NMOSD.

The relationship between aquaporin-4 antibody status and visual tract integrity in neuromyelitis optica spectrum disorders: A visual evoked potential study

BACKGROUND

Optic neuritis (ON) is one of the hallmark symptomatic features of neuromyelitis optica spectrum disorders (NMOSD). The majority of patients with NMOSD present highly specific autoantibodies against aquaporin-4 (AQP4). A number of studies have reported poor visual acuity outcomes in individuals with AQP4 seropositive NMOSD, but no such relationship has been found with regard to visual evoked potentials (VEP) parameters such as the amplitude and latency of the P100 component. In this paper, we aimed (i) to describe VEP responses in patients with NMOSD; (ii) to analyze those results based on a scoring system; and (iii) to investigate the association between the VEPs and AQP4 antibody status.

METHODS

We retrospectively analysed the VEP responses of 40 patients with a diagnosis of NMOSD (according to the 2015 IPND criteria), including 16 with AQP4-postive status (AQP4[+]) and 24 with AQP4-negative status (AQP4[-]). In the first step, we measured the P100 peak latency and P100-N2 peak-to-peak amplitude in each patient. In the second, we converted these measures to the VEP score (0-10) using the scoring proposed by Jung et al. (2008). All recordings were performed using the same VEP device and testing protocol.

RESULTS

Abnormal VEPs were recorded in 25 of 40 patients (62.6%). Of these, 17 (42.5%) had prolonged P100 latency, and 8 (20%) had no response detected in at least one eye. The patients with ON as the initial relapse symptom had significantly higher median VEP scores than those who experienced the longitudinally extensive transverse myelitis (LETM) at the disease onset (7.0 [in-terquar-tile range (IQR), 2.0-8.0] vs. 0.0 [IQR, 0.0-4.0], p<0.001). A lack of VEP response in at least one eye was detected more frequently in the AQP4[+] group than the AQP4[-] group (7/16 vs. 1/24, p<0.005). Logistic regression model controlling for age, gender, disease duration, and the type of relapse at onset showed an independent impact of AQP4[+] status (OR=35.45, p = 0.018) on the higher rate of absent VEP responses. In the entire group of patients (n = 40), those with AQP4[+] showed a small tendency towards a higher median VEP score (4.0 [IQR, 0.0-7.8] vs. 1.0 [IQR, 0.0-4.0], p = 0.304). Among individuals with abnormal responses (n = 25), the patients with AQP4[+] had significantly higher median VEP scores (7.0 [IQR, 4.0-8.5] vs. 3.0 [IQR, 1.0-7.0], p = 0.034) and more common bilateral involvement of the optic tracts (80% vs. 40%, p = 0.048) than those who were seronegative for anti-AQP4 antibody. A median regression analysis model controlling for age, gender, disease duration, type of onset, and number of relapses in last 12 months showed an independent association between the AQP4-positive status and a higher VEP score in patients with NMOSD (t = 2.882, df=2, p = 0.007).

CONCLUSION

VEP study remains a useful tool in the assessment of NMOSD patients. Due to the high prevalence of absent VEPs in NMOSD patients, the scoring system appears to be more applicable for the precise analysis of VEP recordings. There is a positive association between the AQP-positive serostatus and the poorer outcome in VEP responses, especially in patients with severe impairment of the optic nerve(s).

Efficacy and safety of rituximab in patients with refractory neuromyelitis optica spectrum disorders: A prospective observation in Iranian cases

Background:

Rituximab has been used successfully in the recent years for treatment of neuromyelitis optica spectrum disorders (NMOSD). However, a uniform treatment protocol for maintenance therapy and the best interval for evaluation and retreatment have not been postulated. We evaluated the efficacy and safety of rituximab treatment as second line therapy, in Iranian patients with refractory NMOSD, based on annualized relapse rate (ARR) and expanded disability status scale (EDSS).

Methods:

In this prospective before-after study, a total of 18 patients were treated with a loading dose of rituximab (375 mg/m² weekly in 4 consecutive weeks). Flow cytometric determination of CD19⁺ B cell in peripheral blood sample was carried every 6 weeks and patients were re-treated based on B cell repopulation with a single dose of 375 mg/m². Wilcoxon signed rank test was used to evaluate the ARR and EDSS before and after treatment. A p-value of <0.05 was considered statistically significant.

Results:

Of the 18 patients, 10 (55.5%) were relapse-free during the period of follow up. The EDSS scores were reduced in nine (50%) patients and stable in the remaining nine (50%). The mean EDSS score before and after treatment were 4.1±0.4 and 3.7±0.3, respectively, which was statistically significant. There was also a statistically significant reduction in median ARR after treatment (1.48 (range 0.47-5) vs. 0 (range 0-2)). Rituximab administration did not have significant adverse effect in 94% of patients.

Conclusion:

Repeated treatment with Rituximab is an effective and well-tolerated treatment in refractory NMOSD.

Clinical and radiological profile of neuromyelitis optica spectrum disorders in an Ecuadorian cohort

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a complex disease characterized by a severe inflammation of the central nervous system (CNS). This disease typically manifests with recurrent optic neuritis (ON) and acute transverse myelitis (ATM). The clinical and radiological spectrum of NMOSD is little known in Latin America (LATAM) and few reports have been published in the literature so far. In Ecuador, no reports on NMOSD have been published. For this reason we aimed to assess the demographic, clinical and imaging characteristics of patients with NMOSD from third level hospitals from Ecuador.

METHODS

This is a descriptive study in which we assessed medical reports of patients with inflammatory demyelinating diseases who were attended in third level hospitals from Ecuador in 2017. Then we applied the 2015 diagnostic criteria, those patients who met the new NMOSD diagnostic criteria were selected and analyzed. Additionally, exploratory sub-analyses were subsequently carried out.

RESULTS

We identified 59 patients with NMOSD, the relative frequency of NMOSD was 15.9%. The multiple sclerosis (MS) /NMOSD ratio was 5.2:1. Twenty four percent of patients were newly defined as having NMOSD when 2015 criteria was applied. The median time to diagnoses was shorter by the 2015 criteria than 2006 criteria (p<0.001). NMOSD was more prevalent in women (female/male ratio 4.4:1). The disease onset was more frequent at the fourth decade of life. The most common symptoms at the disease onset were ON and the association of ON with ATM. The mean of expanded disability status scale (EDSS) was 4.8 (SD±1.8). Concomitant autoimmune diseases were infrequent in this population (11.9%). The brain magnetic resonance imaging (MRI) abnormalities were present in 25.7% of patients at disease onset. Spinal cord MRI showed longitudinally extensive transverse myelitis (LETM) in 91.5% of cases. Recurrent NMOSD was frequent in this cohort (88%). Positivity for antibodies against aquaporin-4 (AQP4-IgG) which was measured through indirect immunofluorescence assay (IIF) was identified in 81% of the patients tested. Patients with seronegative AQP4-IgG had higher grade of disability than seropositive patients (p<0.05). Ninety eight percent of patients received treatment with immunosuppressive drugs. Three patients died due to gastric cancer (1 patient) and infectious diseases (2 patients).

CONCLUSIONS

This is the first descriptive study in an Ecuadorian cohort of patients with NMOSD. We show a wide epidemiological, clinical and radiological spectrum of NMOSD.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Neuromyelitis optica: a pilot study of clinical presentation and status of serological biomarker AQP4 among patients admitted to a tertiary centre in NCNS, Sudan

Background

Neuromyelitis optica (NMO) is a demyelinating disease primarily affecting the optic nerves and spinal cord. It is distinguished from other demyelinating conditions by the presence of AQP4-IgG and serum aquaporin 4 (AQP4), found mainly in the blood–brain barrier. This descriptive study was conducted from January 2015 to June 2018 at the National Center for Neurological Sciences (NCNS) in Khartoum, Sudan. All participants were Sudanese patients diagnosed with NMO. In our study the selection of cases was based on Dean Wingerchuk diagnostic criteria (2006), which states that the diagnosis of NMO should meet two absolute criteria and two supportive criteria. The absolute criteria are myelitis and optic neuritis, whereas supportive criteria include radiological findings obtained from brain and spinal cord MRI. Furthermore, AQP4-IgG levels were measured from cerebrospinal fluid (CSF) and serum using immunofluorescence. Data were collected by a pre-designed questionnaire and analyzed using SPSS version 17. A p value < 0.05 was considered statistically significant.

Results

A total of 31 patients were enrolled in this study [6 male (19.4%) and 25 female (80.6%)]. The mean age was 38 ± 12.8 years. Motor and visual difficulties were the initial symptoms and occurred in 21 (67.7%) and 10 (32.3%) patients, respectively. Fundoscopy confirmed optic atrophy in 22 (71.0%) patients. The course of the disease revealed one relapse in 21 patients (67.7%). Seropositive AQP4-IgG were seen in 23 patients (79.31%). There was a significant correlation between AQP4 and response to treatment (p ≤ 0.038). The correlation between serum AQP4-IgG, showed that, complete improvement was detected in 2 patients (6.9%) one of them was positive and the other was negative, 20 (69.0%) patients presented with some disability, among them 18 (62.1%) were positive and 2 (6.9%) were negative, while 7 patients showed no improvement (24.1%) 4 out of them were positive (13.8%) and 3 were negative (10.3%).

Conclusion

At the initial presentation of NMO, longitudinal myelitis was observed more frequently than optic neuritis. More than two third of the patients showed strong seropositivity for serum AQP4. Most seropositive patients showed a good response to treatment but with residual disabilities.

[Neuromyelitis optica and neuromyelitis optica spectrum disorders]

The review is devoted to up-to-date data on epidemiology, aspects of the pathogenesis of neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorders (NMOSD). The authors consider a role of myelin oligodendrocyte glycoprotein immunoglobulin G (MOG-IgG) in the syndromes phenotypically similar to NMO and NMOSD. Special attention is drawn to the methods of MOG-IgG antibodies detection and indications for testing. The approaches and management for treatment and prevention of NMO relapses, risks of complications during pregnancy and immediately after delivery, as well as methods for their prevention and treatment, are described.