Diagnosis and Treatment of Neuromyelitis Optica

Network Meta-analysis of Ravulizumab and Alternative Interventions for the Treatment of Neuromyelitis Optica Spectrum Disorder

INTRODUCTION

Anti-aquaporin-4 antibody-positive (AQP4-Ab+) neuromyelitis optica spectrum disorder (NMOSD) is a complement-mediated autoimmune disease in which unpredictable and relapsing attacks on the central nervous system cause irreversible and accumulating damage. Comparative efficacy of new NMOSD therapies, such as ravulizumab, with established therapies is critical in making informed treatment decisions.

METHODS

Efficacy of ravulizumab relative to established AQP4-Ab+ NMOSD treatments, such as eculizumab, inebilizumab, and satralizumab, was evaluated in a Bayesian network meta-analysis (NMA). Data were extracted from trials identified by a systematic literature review. The final evidence base consisted of 17 publications representing five unique and global studies (PREVENT, N-MOmentum, SAkuraSky, SAkuraStar, and CHAMPION-NMOSD). The primary endpoint was time-to-first relapse; other outcomes included annualized relapse rates (ARRs).

RESULTS

For patients receiving monotherapy (monoclonal antibody only), ravulizumab was associated with a lower risk of relapse than inebilizumab (hazard ratio [HR] 0.09, 95% credible interval [CrI] 0.02, 0.57) or satralizumab (HR 0.08, 95% CrI 0.01, 0.55) and was comparable to eculizumab (HR 0.86, 95% Crl 0.16, 4.52). Ravulizumab + immunosuppressive therapy (IST) was associated with a lower risk of relapse than satralizumab + IST (HR 0.15, 95% CrI 0.03, 0.78); the comparison with eculizumab + IST suggested no difference. No patients treated with inebilizumab received background IST and were thus excluded from analysis. The ARR with ravulizumab monotherapy was 98% lower compared with inebilizumab (rate ratio [RR] 0.02, 95% Crl 0.00, 0.38) and satralizumab (RR 0.02, 95% Crl 0.00, 0.42) monotherapies. The ARR with ravulizumab ± IST showed the strongest treatment-effect estimates compared with other interventions.

CONCLUSION

In the absence of head-to-head randomized controlled trials, NMA results suggest ravulizumab, a C5 inhibitor, is likely to be more effective in preventing NMOSD relapse in patients with AQP4-Ab+ NMOSD when compared with other treatments having different methods of action.

Network Meta-analysis of Food and Drug Administration-approved Treatment Options for Adults with Aquaporin-4 Immunoglobulin G-positive Neuromyelitis Optica Spectrum Disorder

INTRODUCTION

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease defined by attacks on the central nervous system that cause irreversible damage. Recent approval of NMOSD therapies warrants investigations of comparative efficacy to inform treatment decisions.

METHODS

A network meta-analysis (NMA) of all U.S. Food and Drug Administration-approved therapies (eculizumab, inebilizumab, and satralizumab) for adults with aquaporin-4 immunoglobulin G-positive (AQP4+) NMOSD was conducted via a systematic literature review (SLR) using data from randomized controlled trials (RCTs). Database searches of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were executed for the SLR. A fixed-effects proportional hazards Bayesian NMA was used to estimate relative treatment effects based on data extracted from RCTs identified during the SLR (search end date: 11 September 2020). Four unique RCTs (N-MOmentum, PREVENT, SAkuraSky, and SAkuraStar) were identified, and data from 29 publications were extracted for analysis. Network scenarios describing the most comparable patient population groups (such as by treatment settings) were evaluated in our analyses. Relative treatment effects were evaluated based on time-to-first relapse and were expressed as hazard ratios (HRs) with 95% credible intervals (CrIs).

RESULTS

In patients treated with a monoclonal antibody only, eculizumab was associated with a lower risk of relapse compared with satralizumab (HR 0.10, 95% CrI 0.01, 0.65) and inebilizumab (HR 0.11, 95% CrI 0.02, 0.68). In patients treated with monoclonal antibody with or without background immunosuppressive therapy (IST), patients treated with eculizumab ± IST were also less likely to relapse than patients treated with satralizumab ± IST (HR 0.24, 95% CrI 0.06, 0.98).

CONCLUSION

The NMA results suggest that complement component 5 (C5) inhibition prevents NMOSD relapses more effectively than broader mechanisms of action.

Th17-Related Cytokines as Potential Discriminatory Markers between Neuromyelitis Optica (Devic's Disease) and Multiple Sclerosis-A Review

Multiple sclerosis (MS) and Devic’s disease (NMO; neuromyelitis optica) are autoimmune, inflammatory diseases of the central nervous system (CNS), the etiology of which remains unclear. It is a serious limitation in the treatment of these diseases. The resemblance of the clinical pictures of these two conditions generates a partial possibility of introducing similar treatment, but on the other hand, a high risk of misdiagnosis. Therefore, a better understanding and comparative characterization of the immunopathogenic mechanisms of each of these diseases are essential to improve their discriminatory diagnosis and more effective treatment. In this review, special attention is given to Th17 cells and Th17-related cytokines in the context of their potential usefulness as discriminatory markers for MS and NMO. The discussed results emphasize the role of Th17 immune response in both MS and NMO pathogenesis, which, however, cannot be considered without taking into account the broader perspective of immune response mechanisms.

[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.

Neuromyelitis optica spectrum standstill in rheumatic systemic autoimmune diseases

Background

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

Main body

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

Conclusion

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

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.

Treatment of recalcitrant orbital inflammatory syndrome with plasmapheresis therapy

Refractory idiopathic orbital inflammation (IOI) represents a management challenge due to its significant proportion of treatment failures. Currently, there are no established guidelines for recalcitrant IOI and majority of immunosuppressive agents have resulted in variable outcomes. Advancements of plasmapheresis therapy can play a significant role in ophthalmological diseases. This treatment has shown to produce a satisfactory therapeutic response in immune-mediated neurological conditions. In this case report, we share our successful experience with the use of plasmapheresis therapy in a patient with recalcitrant IOI.

Rehabilitation of neuromyelitis optica: Two CARE-compliant case reports

RATIONALE

Neuromyelitis optica (NMO), also known as Devic syndrome, is a central nervous system demyelinating disease consisting of optic neuritis and myelitis. Several studies have reported the effects of rehabilitation programs and specific exercises on outcomes in individuals with multiple sclerosis, but few have considered individuals with NMO. We present 2 cases of paraplegia due to NMO with rehabilitation outcome.

PATIENT CONCERNS

The first case corresponds to a 65-year-old woman with NMO presented with C4 incomplete American Spinal Injury Association (ASIA) scale D, and the second case is a 41-year-old woman with NMO presented with C1 incomplete ASIA-C.

DIAGNOSES

Two cases were confirmed by positive anti-aquaporin-4 antibody and presence of T2-weighted hyperintense lesion in spinal cord on magnetic resonance imaging.

INTERVENTION

The first patient planned for focusing on left hand fine motor training through occupational therapy by strengthening and stretching muscle using E-link (Biometrics Ltd, Newport, UK) during 4 weeks, and the second patient received strengthening lower extremity and gait training using a lower-body positive pressure treadmill (AlterG, Anti-Gravity Treadmill, Fremont, CA) during 4 weeks.

OUTCOMES

After a 4-week rehabilitation, the first patient's manual muscle testing was improved to grade 2/5 to 3+/5 in left upper limb specifically. Also, Spinal Cord Independence Measure (SCIM) was improved 79 to 88. Functional gains were made in bathing, upper-extremity dressing, and using chopsticks independently. Also, the second patient's manual muscle testing improved to grades 1 to 2/5 to 3 to 4/5 generally, and ASIA scale improved C5 incomplete ASIA-D. SCIM was improved to by allowing walking independently and increasing lower-extremity dressing and toileting ability.

LESSONS

An intensive, multidisciplinary rehabilitation program may lead to neurological and functional gains in patients with NMO.

Mast cells: A key component in the pathogenesis of Neuromyelitis Optica Spectrum Disorder?

Neuromyelitis Optica Spectrum Disorder (NMOSD) is characterized as an autoimmune, inflammatory and demyelinating disease of the Central Nervous System (CNS). Its pathogenesis is due to the presence of anti-aquaporin 4 immunoglobulin G1 antibodies (anti-AQP4IgG), with presence of lymphocytes T Helper 1 and 17 (TH1 and TH17), in addition to previous neuroinflammation. The Mast cell (MC) is a granular cell present in all vascularized tissues, close to vessels, nerves, and meninges. In CNS, MCs are in the area postrema, choroid plexus, thalamus and hypothalamus. MC has ability to transmigrate between the nervous tissue and the lymphoid organs, interacting with the cells of both systems. These cells reach the CNS during development through vessel migration. Most MCs reside on the abluminal side of the vessels, where it can communicate with neurons, glial cells, endothelial cells and the extracellular matrix. Considering the role of MCs in neurodegenerative diseases has been extensively discussed, we hypothesized MCs participate in the pathogenesis of NMOSD. This cell represents an innate and adaptive immune response regulator, capable of faster responses than microglial cells. The study of MCs in NMOSD can help to elucidate the pathogenesis of this disease and guide new research for the treatment of patients in the future. We believe this cell is an important component in the cascade of NMOSD neuroinflammation.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Anti-aquaporin-4 titer is not predictive of disease course in neuromyelitis optica spectrum disorder: A multicenter cohort study

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disease associated with a serological antibody to aquaporin-4 (AQP4) detectable in up to 80% of patients. The enzyme-linked immunosorbent assay (ELISA) is one of the most popular methods of testing for anti-AQP4 antibodies that results with a titer in which < 3 Units/ml is negative, 3-5 is borderline and 5+ is positive. The value of the positive titer in predicting long term disease course is currently unknown.

METHODS

This is a retrospective analysis of NMOSD patients from five centers around the world: Baltimore, USA, Philadelphia, USA, Shanghai, China, Berlin, Germany, and Medellin, Columbia, where ELISA titers on anti-AQP4 antibody testing is available. Inclusion criteria include a diagnosis of NMOSD and seropositive anti-AQP4 antibody test with titer = /> 3 Units/ml. Patients were stratified into three groups by titer: 3-30 Units/ml (low), 31-100 Units/ml (medium), and 101+ Units/ml (high). Demographic factors such as age at onset, race, and sex were collected along with clinical features such as annualized relapse rate, duration of disease, location of relapses, and treatment history.

RESULTS

A total of 139 NMOSD patients met criteria for inclusion in this study, stratified into three groups by titer: 42 subjects with low titers of 3-30 Units/ml, 30 subjects with medium titers of 31-100 Units/ml and 67 subjects with high titers of 101 or greater ELISA Units/ml. The average age at onset, sex and race distribution were not significantly different among the groups. The number of patients untreated in each group was similar (< 25%) as was the average annualized relapse rate (0.591-0.821 relapses/year). With an average of 10 years follow up, the average disability level was not different among the three titer groups (EDSS range 3.03-3.48). The distribution of lesions, as well as their preventive treatment regimens did not differ significantly.

CONCLUSION

Beyond a positive/borderline/negative result, the titer of the anti-AQP4 antibody ELISA assay is not predictive in the disease course for patients with NMOSD. Low titer patients experience the same disease course as medium-titer and high-titer anti-AQP4 antibody patients with NMOSD.

Neuromyelitis optica study model based on chronic infusion of autoantibodies in rat cerebrospinal fluid

Background

Devic’s neuromyelitis optica (NMO) is an autoimmune astrocytopathy, associated with central nervous system inflammation, demyelination, and neuronal injury. Several studies confirmed that autoantibodies directed against aquaporin-4 (AQP4-IgG) are relevant in the pathogenesis of NMO, mainly through complement-dependent toxicity leading to astrocyte death. However, the effect of the autoantibody per se and the exact role of intrathecal AQP4-IgG are still controversial.

Methods

To explore the intrinsic effect of intrathecal AQP4-IgG, independent from additional inflammatory effector mechanisms, and to evaluate its clinical impact, we developed a new animal model, based on a prolonged infusion of purified immunoglobulins from NMO patient (IgG^AQP4+, NMO-rat) and healthy individual as control (Control-rat) in the cerebrospinal fluid (CSF) of live rats.

Results

We showed that CSF infusion of purified immunoglobulins led to diffusion in the brain, spinal cord, and optic nerves, the targeted structures in NMO. This was associated with astrocyte alteration in NMO-rats characterized by loss of aquaporin-4 expression in the spinal cord and the optic nerves compared to the Control-rats (p = 0.001 and p = 0.02, respectively).

In addition, glutamate uptake tested on vigil rats was dramatically reduced in NMO-rats (p = 0.001) suggesting that astrocytopathy occurred in response to AQP4-IgG diffusion. In parallel, myelin was altered, as shown by the decrease of myelin basic protein staining by up to 46 and 22 % in the gray and white matter of the NMO-rats spinal cord, respectively (p = 0.03). Loss of neurofilament positive axons in NMO-rats (p = 0.003) revealed alteration of axonal integrity. Then, we investigated the clinical consequences of such alterations on the motor behavior of the NMO-rats. In a rotarod test, NMO-rats performance was lower compared to the controls (p = 0.0182). AQP4 expression, and myelin and axonal integrity were preserved in AQP4-IgG-depleted condition. We did not find a major immune cell infiltration and microglial activation nor complement deposition in the central nervous system, in our model.

Conclusions

We establish a link between motor-deficit, NMO-like lesions and astrocytopathy mediated by intrathecal AQP4-IgG. Our study validates the concept of the intrinsic effect of autoantibody against surface antigens and offers a model for testing antibody and astrocyte-targeted therapies in NMO.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-016-0577-8) contains supplementary material, which is available to authorized users.

Membrane-based Therapeutic Plasma Exchange: A New Frontier for Nephrologists

Therapeutic plasma exchange has long been utilized to manage a variety of immune-mediated diseases. The underlying principle is the removal of a circulating pathogenic substance from the plasma and substitution with a replacement fluid. Different methodologies of plasma separation include the use of centrifuge, which relies on the variation in the specific gravity of blood components, and membrane-based separation, which relies on particle size. With advancements in technology and clinical insight into disease pathophysiology, membrane technology has become more biocompatible, safer, and more adaptable to conventional hemodialysis and hemofiltration machines. As such, nephrologists, who are familiar with management of extracorporeal blood purification systems, are increasingly involved with membrane-based plasma separation. This review aims to highlight the technical aspects of membrane-based separation, review the prescription for therapy, and draw comparisons with the centrifuge-based technique when applicable.

Pain and spinal cord imaging measures in children with demyelinating disease

Pain is a significant problem in diseases affecting the spinal cord, including demyelinating disease. To date, studies have examined the reliability of clinical measures for assessing and classifying the severity of spinal cord injury (SCI) and also to evaluate SCI-related pain. Most of this research has focused on adult populations and patients with traumatic injuries. Little research exists regarding pediatric spinal cord demyelinating disease. One reason for this is the lack of reliable and useful approaches to measuring spinal cord changes since currently used diagnostic imaging has limited specificity for quantitative measures of demyelination. No single imaging technique demonstrates sufficiently high sensitivity or specificity to myelin, and strong correlation with clinical measures. However, recent advances in diffusion tensor imaging (DTI) and magnetization transfer imaging (MTI) measures are considered promising in providing increasingly useful and specific information on spinal cord damage. Findings from these quantitative imaging modalities correlate with the extent of demyelination and remyelination. These techniques may be of potential use for defining the evolution of the disease state, how it may affect specific spinal cord pathways, and contribute to the management of pediatric demyelination syndromes. Since pain is a major presenting symptom in patients with transverse myelitis, the disease is an ideal model to evaluate imaging methods to define these regional changes within the spinal cord. In this review we summarize (1) pediatric demyelinating conditions affecting the spinal cord; (2) their distinguishing features; and (3) current diagnostic and classification methods with particular focus on pain pathways. We also focus on concepts that are essential in developing strategies for the detection, monitoring, treatment and repair of pediatric myelitis.

•

Pain is a major presenting symptom in children with myelitis.

•

Currently used imaging has limited sensitivity to myelin content.

•

We provide a summary on pediatric demyelinating conditions.

•

We review pain involvement and pathways affected by demyelination.

•

We review imaging modalities for the diagnosis and monitoring of myelitis.

IL2RA Allele Increases Risk of Neuromyelitis Optica in Southern Han Chinese

Background:

Neuromyelitis optica (NMO) and multiple sclerosis (MS) are chronic neuro-inflammatory diseases believed to arise from complex interactions between environmental and genetic factors. Recently, single nucleotide polymorphisms (SNPs) in interleukin (IL)-2 and -7 receptor alpha genes have been identified as novel susceptibility alleles for MS in genome-wide association studies. However, similar research on NMO is limited. We aimed to investigate the association of IL2RA SNPs rs2104286 and rs12722489 and IL7RA SNP rs6897932 with Southern Han Chinese NMO and MS patients.

Methods:

Frequencies of the three SNPs were examined in Southern Han Chinese mS cases (n=78), NMS cases (n=67) and controls (n=133) using sequencing-based typing.

Results:

The rs2104286G frequency in the IL2RA gene was significantly higher in NMO patients than in controls (puncorr=0.013, pcorr=0.026, OR:1.942, 95%CI:1.146-3.291).

Conclusion:

The rs2104286 G allele in IL2RA is present at higher frequencies in NMO patients than in healthy controls within a Southern Han Chinese population.

Neuromyelitis optica spectrum disorders without and with autoimmune diseases

Background

Neuromyelitis optica spectrum disorder (NMOSD) can coexist with non-organ-specific or organ-specific autoimmune diseases. The aim of this study was to investigate and compare the features between NMOSD without and with autoimmune diseases, and NMOSD with non-organ-specific and organ-specific autoimmune diseases.

Methods

One hundred and fifty five NMOSD patients without autoimmune diseases (n = 115) and with autoimmune diseases (n = 40) were enrolled. NMOSD with autoimmune diseases were divided by organ-specific autoimmune diseases. The clinical, laboratory and magnetic resonance imaging features between two groups were assessed.

Results

Motor deficit was less frequent in NMOSD patients with non-organ-specific autoimmune diseases (p = 0.024). Cerebrospinal fluid white blood cell and protein, serum C-reactive protein and immunoglobulin G were lower in NMOSD patients without autoimmune diseases, while several autoantibodies seropositivity and thyroid indexes were significantly higher in NMOSD patients with autoimmune diseases (p < 0.05). No difference was found in other clinical and laboratory characteristics between different NMOSD subtypes (p > 0.05). NMOSD patients with autoimmune diseases had higher brain abnormalities than NMOSD without autoimmune diseases (p < 0.001).

Conclusions

The characteristics between NMOSD without and with autoimmune diseases were similar. NMOSD with autoimmune diseases have high frequency of brain abnormalities.

Complement activation in patients with neuromyelitis optica

The role of complement has been demonstrated in experimental models of neuromyelitis optica (NMO), however, only few studies have analysed complement components longitudinally in NMO patients. We measured serum or plasma concentrations of anti-C1q antibodies and complement split products C3a and C4a and soluble C5b-9 in patients with NMO, multiple sclerosis and healthy controls. NMO patients had higher levels of C3a and anti-C1q antibodies than healthy controls. C3a levels correlated with disease activity, neurological disability and aquaporin-4 IgG in NMO patients suggesting a role of the alternative pathway of complement in the pathogenesis of NMO and supporting the strategy of therapeutic complement inhibition.

Structural brain abnormalities are related to retinal nerve fiber layer thinning and disease duration in neuromyelitis optica spectrum disorders

BACKGROUND

Although aquaporin-4 (AQP4) is widely expressed in the human brain cortex, lesions are rare in neuromyelitis optica (NMO) spectrum disorders (NMOSD). Recently, however, several studies have demonstrated occult structural brain atrophy in NMO.

OBJECTIVE

This study aims to investigate magnetic resonance imaging (MRI) patterns of gray matter (GM) and white matter (WM) abnormalities in patients with NMOSD and to assess the visual pathway integrity during disease duration correlation of the retinal nerve fiber layer (RNFL) and pericalcarine cortex thickness.

METHODS

Twenty-one patients with NMOSD and 34 matched healthy controls underwent both high-field MRI (3T) high-resolution T1-weighted and diffusion-tensor MRI. Voxel-based morphometry, cortical analyses (Freesurfer) and diffusion-tensor imaging (DTI) analyses (TBSS-FSL) were used to investigate brain abnormalities. In addition, RNFL measurement by optic-coherence tomography (OCT) was performed.

RESULTS

We demonstrate that NMOSD is associated with GM and WM atrophy, encompassing more frequently the motor, sensory and visual pathways, and that the extent of GM atrophy correlates with disease duration. Furthermore, we demonstrate for the first time a correlation between RNFL and pericalcarine cortical thickness, with cortical atrophy evolving over the course of disease.

CONCLUSIONS

Our findings indicate a role for retrograde and anterograde neurodegeneration in GM atrophy in NMOSD. However, the presence atrophy encompassing almost all lobes suggests that additional pathomechanisms might also be involved.

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.

[Neuromyelitis optica]

BACKGROUND

Neuromyelitis optica (NMO) is a rare autoimmune inflammatory disease of the central nervous system that is characterized mainly by recurrent optic neuritis and longitudinally extensive transverse myelitis. The aim of this article is to present current knowledge on the clinical features, diagnosis, pathogenesis and treatment of the condition.

METHOD

The article is based on a discretionary selection of English-language original articles, meta-analyses and review articles found in PubMed, and on the authors' own experience with the patient group.

RESULTS

Neuromyelitis optica was previously assumed to be a variant of multiple sclerosis (MS), but the discovery of aquaporin-4 antibodies in patients with neuromyelitis optica has led to this view being revised. The cause of the condition is still unknown, but it has been shown that the antibodies bind selectively to a water channel expressed mainly on astrocytes at the blood-brain-barrier, which has an important role in the regulation of brain volume and ion homeostasis. Clinically, the condition presents as optic neuritis and/or transverse myelitis. A diagnosis is made on the basis of case history, clinical examination, MRI of the brain and spinal cord, analysis of cerebrospinal fluid, visual evoked potentials and a blood test with analysis of aquaporin-4 antibodies. Once a diagnosis has been made, rapid treatment is important. In the acute phase, intravenous methylprednisolone is recommended. There are several options for preventative treatment, but the primary recommendations are oral prednisolone and azathioprine or intravenous infusion of rituximab. Treatment is distinct from the treatment of MS and some of the immunomodulatory drugs commonly used in MS can lead to worsening of neuromyelitis optica.

INTERPRETATION

The condition is an important differential diagnosis of MS, but differs from MS in terms of clinical features, prognosis and treatment. Patients have a high risk of sequelae following relapses, and therefore early diagnosis and treatment is important.

Responsiveness to reduced dosage of rituximab in Chinese patients with neuromyelitis optica

OBJECTIVE

To determine the effect of a lower dose of rituximab in depleting B lymphocytes, maintaining low B-cell counts, and relapse in patients with neuromyelitis optica (NMO) and NMO spectrum disorders.

METHODS

We treated 5 Chinese patients with deteriorating NMO and NMO spectrum disorders with a 100-mg IV infusion of rituximab once a week for 3 consecutive weeks, followed by additional infusion of the same dosage depending on circulating B-cell repopulation.

RESULTS

This reduced dosage of rituximab was sufficient to deplete B cells and maintain low B-cell counts. None of the treated patients experienced relapse, and all patients exhibited stabilized or improved neurologic function during the 1-year follow-up period. MRI revealed the absence of new lesions, no enhancement in spinal cord and brain, a significant shrinkage of spinal cord segments, and a reduction/disappearance of previous brain lesions.

CONCLUSION

A lower dosage of rituximab may be sufficient in depleting B cells, maintaining low B-cell counts, and preventing disease progression in Chinese patients with NMO.

Clinical, radiographic characteristics and immunomodulating changes in neuromyelitis optica with extensive brain lesions

Background

Neuromyelitis optica (NMO) shows various brain magnetic resonance imaging (MRI) abnormalities with recurrent central nervous system (CNS) attacks, although predominantly affecting the spinal cord and optic nerve. However, NMO with extensive involvement of the brain has infrequently been studied. We investigated the clinical, radiographic features and immunomodulating changes of NMO patients with extensive brain lesions (EBLs) in China.

Methods

NMO patients (including 16 NMO patients with EBLs and 53 NMO patients without EBLs) hospitalized during January 2006 and February 2010 were recruited and analyzed retrospectively. Data of clinical characteristics, magnetic resonance imaging (MRI) features, laboratory abnormalities, treatment details and outcomes were analyzed. All the patients received the follow-up visits for two years.

Results

EBLs in NMO were classified into four categories according to their respective MRI characteristics: 1) Tumefactive-like lesions (n=4, 25%); 2) Acute disseminated encephalomyelitis (ADEM)-like lesions (n=6, 37.5%); 3) Multiple sclerosis (MS)-like lesions (n=5, 31.25%); 4) Posterior reversible encephalopathy syndrome (PRES)-like lesions (n=1, 6.25%). NMO patients with EBLs had higher rates of encephalopathy symptoms (37.5% vs. 5.6%, p = 0.004), homonymous hemianopia (18.8% vs. 0%, p = 0.011) and AQP4 seropositivity (100% vs. 69.8%, p = 0.008) than NMO patients without EBLs (NEBLs). Immunomodulating changes (including the levels of C3, C4, ESR and CRP) were significantly higher in patients with EBLs than those without EBLs. The relapse times in EBLs during the follow-up period were more frequent than those happened in NEBLs (1.88 ± 0.30 vs. 1.23 ± 0.14, p = 0.04). The EDSS scores in EBLs patients were also much higher than those in NEBLs throughout all the whole visits of follow-up.

Conclusions

The presence of EBLs in NMO may indicate a higher diseases activity and portend a worse prognosis. CRP is a useful marker in monitoring diseases activity. Systemic inflammation may be crucial to the formation of EBLs in NMO.

The neuro-ophthalmology of multiple sclerosis

Multiple sclerosis (MS) is a disease marked by focal demyelinating inflammatory plaques throughout the CNS. Neuro-ophthalmologic sequelae are common in MS and may arise from the disease itself or from treatment of the disease. Both afferent and efferent functions may be affected. Despite much progress, our understanding of the pathophysiology of MS, and the efficacy of our available treatments, remain inadequate. Here, we review the chief neuro-ophthalmologic abnormalities associated with MS and discuss the emerging diagnostic and therapeutic advances that are likely to further our understanding of MS and its treatment.

Aquaporin-4 antibodies are not related to HTLV-1 associated myelopathy

Introduction

The seroprevalence of human T-cell leukemia virus type 1 (HTLV-1) is very high among Brazilians (∼1∶200). HTLV-1 associated myelopathy or tropical spastic paraparesis (HAM/TSP) is the most common neurological complication of HTLV-1 infection. HAM/TSP can present with an acute/subacute form of longitudinally extensive myelitis, which can be confused with lesions seen in aquaporin-4 antibody (AQP4-Ab) positive neuromyelitis optica spectrum disorders (NMOSD) on MRI. Moreover, clinical attacks in patients with NMOSD have been shown to be preceded by viral infections in around 30% of cases.

Objective

To evaluate the frequency of AQP4-Ab in patients with HAM/TSP. To evaluate the frequency of HTLV-1 infection in patients with NMOSD.

Patients and Methods

23 Brazilian patients with HAM/TSP, 20 asymptomatic HTLV-1+ serostatus patients, and 34 with NMOSD were tested for AQP4-Ab using a standardized recombinant cell based assay. In addition, all patients were tested for HTLV-1 by ELISA and Western blotting.

Results

20/34 NMOSD patients were positive for AQP4-Ab but none of the HAM/TSP patients and none of the asymptomatic HTLV-1 infected individuals. Conversely, all AQP4-Ab-positive NMOSD patients were negative for HTLV-1 antibodies. One patient with HAM/TSP developed optic neuritis in addition to subacute LETM; this patient was AQP4-Ab negative as well. Patients were found to be predominantly female and of African descent both in the NMOSD and in the HAM/TSP group; Osame scale and expanded disability status scale scores did not differ significantly between the two groups.

Conclusions

Our results argue both against a role of antibodies to AQP4 in the pathogenesis of HAM/TSP and against an association between HTLV-1 infection and the development of AQP4-Ab. Moreover, the absence of HTLV-1 in all patients with NMOSD suggests that HTLV-1 is not a common trigger of acute attacks in patients with AQP4-Ab positive NMOSD in populations with high HTLV-1 seroprevalence.

Neuromyelitis optica in a patient with pemphigus foliaceus

Neuromyelitis optica (NMO, also eponymously known as Devic's disease) is an immune-mediated demyelinating disease of the central nervous system that can lead to significant disability. Pediatric NMO is a rare disorder often reported after an infection. The authors report a 16 year-old female patient with pemphigus foliaceus who developed subacute optic neuritis followed by cervical transverse myelitis. Restricted distribution of the lesions in the optic nerve and spinal cord was confirmed by ophthalmological evaluation and magnetic resonance imaging of the brain and spinal cord. She was started on intravenous methylprednisolone and then given a maintenance oral prednisone. Subsequently, she was treated with a nonsteroidal immunosuppressant, mycophenolate mofetil, with a target dose of 1000 mg twice a day. Over the course of months, patient noted significant recovery of previous deficits and resolution of the cervical cord enhancement, expansion and cystic dilatation that was previously seen. This case is noteworthy for being the first patient reported with neuromyelitis optica associated with pemphigus foliaceus.

Update on neuromyelitis optica: natural history and management

Neuromyelitis optica or Devic disease is an inflammatory disorder of the central nervous system. It is caused by antibodies that attack aquaporin 4 water channels in the cell membrane of astrocytic foot processes at the blood brain barrier. It can involve the optic nerve, the spinal cord and beyond. Here we review its pathophysiology, clinical features, and therapy.

[Inflammatory diseases of the spinal column and the myelon]

Inflammatory diseases of the spine and the spinal cord (myelon) can be caused by a wide range of pathological conditions. Except for degenerative inflammatory diseases of the spine, infectious and autoimmune disorders are relatively rare. The latter can also be a significant source of pain and disability, especially if these hard to diagnose conditions go untreated. In cases of advanced disease some entities, such as spondylodiscitis or rheumatoid arthritis can cause severe neurological impairment especially by progressive intraspinal spread. Inflammation of the myelon cannot be depicted with conventional radiographs in general and by computed tomography only occasionally. In these cases magnetic resonance imaging is the method of choice to detect early abnormalities of the myelon and to provide detailed information for the differential diagnosis.

Anti-NMDA receptor encephalitis. The disorder, the diagnosis and the immunobiology

Anti-NMDAR encephalitis is a newly characterized syndrome with a progressive, predictable clinical course and the possibility of effective treatment. Accurate and timely diagnosis is critical to selection and implementation of treatments, and optimal patient outcomes. Outcomes are improved with early diagnosis via indirect immunofluorescence or cell-based assays, and the rapid and appropriate administration of immunosuppressant and anti-psychotic therapies. Three possible scenarios accounting for the immunopathogenesis of anti-NMDAR encephalitis are presented, with the most probable one being that of paraneoplastic autoimmunity. Future efforts in this disorder should focus on elucidating the mechanisms that contribute to initiation of this antibody response, as well as exploring the role of tumors, infectious triggers and immune-reactivation. Finally, accessible tools need to be developed that allow for reliable identification of specific antibody markers against synaptic proteins.

Longitudinal extensive transverse myelitis--it's not all neuromyelitis optica

Longitudinal extensive transverse myelitis (LETM) is defined as a spinal cord lesion that extends over three or more vertebrae, as seen on MRI of the spine. The clinical presentation of a patient with LETM is often dramatic and can consist of paraparesis or tetraparesis, sensory disturbances, and gait, bladder, bowel and/or sexual dysfunction. LETM is a characteristic feature of neuromyelitis optica, but such spinal lesions can also occur in various other autoimmune and inflammatory diseases that involve the CNS--such as multiple sclerosis, sarcoidosis or Sjögren syndrome--or in infectious diseases with CNS involvement. Patients with a neoplastic disorder or traumatic spinal cord injury can also present with longitudinal spinal lesions. In this Review, the signs and symptoms that suggest various etiologies and differential diagnoses of LETM are described, and illustrated by educational case studies. The best therapeutic options for patients with each diagnosis are also discussed.

Quantitative measurement of anti-aquaporin-4 antibodies by enzyme-linked immunosorbent assay using purified recombinant human aquaporin-4

BACKGROUND

Antibodies to aquaporin-4 (AQP4-Ab), known as NMO-IgG, are a sensitive and specific marker for neuromyelitis optica (NMO).

METHODS

To develop an enzyme-linked immunosorbent assay (ELISA) for AQP4-Ab, we expressed M23 isoform of human AQP4 in a baculovirus system, and used it as an antigen. We measured AQP4-Ab in the sera of 300 individuals: 64 with definite NMO, 31 with high-risk NMO, 105 with multiple sclerosis (MS), 57 with other neurological diseases (ONDs), and 43 healthy controls. We also performed longitudinal measurements of AQP4-Ab in 787 samples collected from 51 patients with definite or high-risk NMO.

RESULTS

AQP4-Abs were positive in 72% with definite NMO, 55% with high-risk NMO, and 4% with MS, but none of the OND patients and the healthy individuals. The longitudinal measurement showed AQP4-Ab levels correlating with disease activity. Out of 38 initially seropositive patients, 21 became seronegative under effective immunosuppressive therapy. During most relapses, the serum AQP4-Ab levels were either high or rising compared with the previous value, although rising AQP4-Ab levels did not always lead to acute exacerbation. Two of the 13 initially seronegative patients converted to seropositive following acute exacerbations.

CONCLUSIONS

We established an AQP4-Ab ELISA, which could be a potential monitoring tool of disease activity.

Conventional apheresis therapies: a review

This article reviews advances in the scientific basis and medical practice of plasmapheresis and cytapheresis therapies. Newly-characterized autoantibodies in neuromyelitis optica, Guillain-Barre variants, anti-neutrophil cytoplasmic antibody (ANCA) vasculitides, etc., exemplify the modern molecular biology which now provides a rigorous framework of understanding for the clinical practice of plasmapheresis. Clinical trials continue to clarify the appropriate use of therapeutic plasmapheresis (TPE) in these and other diseases. Centrifugal (cTPE) and membrane filtration (mTPE) types of plasmapheresis are compared, with details of the plasmapheresis prescription, anticoagulation choices, replacement fluids and other practical considerations. Plasma removal is more efficient with cTPE; mTPE systems have a lower plasma extraction ratio, and therefore require higher blood flow rates or longer procedure times. Autoantibodies and other pathogenic macromolecules targeted for removal by plasmapheresis can be depleted predictably when the plasma is discarded, as in conventional TPE. On-line plasma processing to regenerate the patient's own plasma avoids the need for replacement albumin solutions or plasma transfusion, but is inherently less efficient at removing the target molecule, so usually requires a longer procedure. Therapeutic white cell reduction (leukapheresis), platelet reduction (thrombocytapheresis) and red cell exchange (erythrocytapheresis) require centrifugal apheresis systems.

AQP4 antibody-positive Thai cases: clinical features and diagnostic problems

OBJECTIVE

To evaluate the prevalence of aquaporin-4 (AQP4) antibody in Thai patients with idiopathic inflammatory demyelinating CNS diseases (IIDCDs) and to analyze the significance of the autoantibody to distinguish neuromyelitis optica (NMO) and other NMO spectrum disorders (ONMOSDs) from other IIDCDs, especially multiple sclerosis (MS).

METHODS

We retrospectively evaluated 135 consecutive patients with IIDCDs seen at the MS clinic at Siriraj Hospital, Bangkok, Thailand, and classified them into NMO, ONMOSDs, optic-spinal MS (OSMS), classic MS (CMS), and clinically isolated syndrome (CIS) groups in this order with accepted diagnostic criteria. The patients' coded sera were tested separately for AQP4 antibody. Then the relations between the clinical diagnosis and the AQP4 antibody serologic status were analyzed.

RESULTS

Among the 135 patients, 53 (39.3%) were AQP4 antibody-positive. Although the AQP4 antibody-positive group had features of NMO, such as female predominance, long cord lesions (>3 vertebral bodies), and CSF pleocytosis, only 18 patients (33% of 54) fully met Wingerchuk 2006 criteria except for AQP4 antibody-seropositive status. We also detected some AQP4 antibody-positive patients in the OSMS (4 of 7), CMS (11 of 46), and CIS (1 of 16) groups. These patients had been misdiagnosed with MS because they often had brain lesions and never underwent spinal cord MRI examination or lacked long cord lesions.

CONCLUSIONS

AQP4 antibody was highly prevalent (almost 40%) in Thai patients with IIDCDs. Moreover, only one-third of AQP4 antibody-positive patients fully met Wingerchuk 2006 criteria, and many were misdiagnosed with MS. A sensitive AQP4 antibody assay is required in this region because the therapy for NMO is different from that for MS.

Diagnosis of multiple sclerosis

There is no pathognomonic symptom, sign, or paraclinical result that provides an unfailingly accurate diagnosis of multiple sclerosis (MS), and hence, MS remains largely a clinical diagnosis. However, being a clinical diagnosis does not mean that the diagnosis of MS is one of exclusion. Increasingly sophisticated guidelines and objective paraclinical findings are generally sufficient to allow the clinician to confirm or rule out the diagnosis with confidence. This article presents the most recent guidelines for using clinical, radiological, and other paraclinical information and the red flags that should alert the clinician to investigate other diagnostic possibilities.

[Recurrent acute rhombencephalomyelitis in an adult or neuromyelitis optica? Presentation of a case]

INTRODUCTION

The lack of accepted homogeneous criteria for the definition of some demyelinating diseases makes diagnostic characterization difficult and limits data interpretation and therapeutic recommendations. Recurrent encephalomyelitis (ADE-R) along with borderline cases of neuromyelitis optica (NMO) are especially controversial.

OBJECTIVE

To describe the clinical and radiological evolution of an adult-onset ADE-R versus NMO case throughout 9 years of follow-up.

PATIENT AND METHODS

Our patient presented with severe symptoms of rhombencephalomyelitis and the cranial and spinal magnetic resonance imaging (MRI) showed large lesions, with gadolinium enhancement in brainstem and spinal cord, correlating with the clinical picture. Infectious aetiology was excluded, IgG index was normal and NMO antibodies were negative. After treatment with intravenous corticosteroids and plasmapheresis, there was excellent recovery in the acute phase. During follow-up, seven relapses have occurred, mainly in the spinal cord, with good recovery and the same symptomatology, albeit with different severity. Immunosuppressive treatment was introduced since the beginning.

CONCLUSIONS

Our case shares common features of both ADE-R and NMO, illustrating that diagnostic characterization is not easy in spite of current criteria.