NMO-IgG predicts the outcome of recurrent optic neuritis

Neuromyelitis Optica: Review and Utility of Testing Aquaporin-4 Antibody in Typical Optic Neuritis

Neuromyelitis optica (NMO) is an autoimmune, inflammatory demyelinating disorder often leading to severe vision impairment and disability. The discovery of a diagnostic biomarker, the aquaporin-4 antibody (AQP4-IgG), transformed the clinical diagnosis and treatment of NMO and broadened the spectrum of disease [NMO spectrum disorders (NMOSD)]. Though the antibody is highly sensitive and specific to NMOSD, routine testing in patients with typical optic neuritis is considered controversial. This article will provide a brief review of NMOSD and highlight the pros and cons of routine testing in typical optic neuritis.

Recurrent Optic Neuritis as the Initial Symptom in Demyelinating Diseases

Background and Purpose

Optic neuritis (ON) is an inflammation of the optic nerve that can be recurrent, with unilateral or bilateral presentation. Diagnosing recurrent cases may be challenging. We aimed to compare patients with recurrent ON as their initial symptom according to their following final diagnoses: multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), or chronic relapsing inflammatory optic neuropathy (CRION).

Methods

The medical records of patients with initial recurrent ON who were followed at the Neuroimmunology Clinic of the Federal University of São Paulo between 2004 and 2016 were analyzed retrospectively. Patients were classified according to their final diagnosis into MS, NMOSD, or CRION, and the characteristics of these groups were compared to identify predictive factors.

Results

Thirty-three patients with recurrent ON were included, and 6, 14, and 13 had final diagnoses of MS, NMOSD, and CRION, respectively. Most of the patients were female with unilateral and severe ON in their first episode, and the initial Visual Functional System Score (VFSS) was ≥5 in 63.6%, 85.7%, and 16.7% of the patients with CRION, NMOSD, and MS, respectively. Anti-aquaporin-4 antibodies were detected in 9 of 21 (42.8%) tested patients. Seven of nine (77.8%) seropositive NMOSD patients experienced transverse myelitis episodes during the follow-up period. A multivariate regression analysis showed that the VFSS at the last medical appointment predicted the final diagnosis.

Conclusions

A lower VFSS at the last medical appointment was predictive of MS. Patients with NMOSD and CRION have similar clinical characteristics, whereas NMOSD patients tend to have worse visual acuity.

Aquaporin-4 and Myelin Oligodendrocyte Glycoprotein Autoantibody Status Predict Outcome of Recurrent Optic Neuritis

PURPOSE

To determine the aquaporin-4 and myelin oligodendrocyte glycoprotein (MOG) immunoglobulin G (IgG) serostatus and visual outcomes in patients with recurrent optic neuritis (rON) initially seeking treatment.

DESIGN

Cross-sectional cohort study.

PARTICIPANTS

The study identified patients by searching the Mayo Clinic computerized central diagnostic index (January 2000-March 2017). The 246 eligible patients fulfilled the following criteria: (1) initially seeking treatment for at least 2 consecutive episodes of optic neuritis (ON) and (2) serum available for testing.

METHODS

Serum was tested for aquaporin-4 IgG and MOG IgG1 using an in-house validated flow cytometric assay using live HEK293 cells transfected with M1 aquaporin-4 or full-length MOG.

MAIN OUTCOMES MEASURES

Aquaporin-4 IgG and MOG IgG1 serostatus, clinical characteristics, and visual outcomes.

RESULTS

Among 246 patients with rON at presentation, glial autoantibodies were detected in 32% (aquaporin-4 IgG, 19%; MOG IgG1, 13%); 186 patients had rON only and 60 patients had rON with subsequent additional inflammatory demyelinating attacks (rON-plus group). The rON-only cohort comprised the following: double seronegative (idiopathic), 110 patients (59%); MOG IgG1 positive, 27 patients (15%; 4 with chronic relapsing inflammatory optic neuropathy); multiple sclerosis (MS), 25 patients (13%); and aquaporin-4 IgG positive, 24 patients (13%). The rON-plus cohort comprised the following: aquaporin-4 IgG positive, 23 patients (38%); MS, 22 patients (37%); double seronegative, 11 patients (18%); and MOG IgG1 positive, 4 patients (7%). The annualized relapse rate for the rON-only group was 1.2 for MOG IgG1-positive patients, 0.7 for double-seronegative patients, 0.6 for aquaporin-4 IgG-positive patients, and 0.4 for MS patients (P = 0.005). The median visual acuity (VA) of patients with the worst rON-only attack at nadir were hand movements in aquaporin-4 IgG-positive patients, between counting fingers and hand movements in MOG IgG1-positive patients, 20/800 in idiopathic patients, and 20/100 in MS patients (P = 0.02). The median VA at last follow-up for affected eyes of the rON-only cohort were counting fingers for aquaporin-4 IgG-positive patients, 20/40 for idiopathic patients, 20/25 for MS patients and MOG IgG1-positive patients (P = 0.006). At 5 years after ON onset, 59% of aquaporin-4 IgG-positive patients, 22% of idiopathic patients, 12% of MOG IgG1-positive patients, and 8% of MS patients were estimated to have severe visual loss.

CONCLUSIONS

Glial autoantibodies (MOG IgG1 or aquaporin-4 IgG) are found in one third of all patients with rON. Aquaporin-4 IgG seropositivity predicts a worse visual outcome than MOG IgG1 seropositivity, double seronegativity, or MS diagnosis. Myelin oligodendrocyte glycoprotein IgG1 is associated with a greater relapse rate but better visual outcomes.

Chloride imbalance is involved in the pathogenesis of optic neuritis in neuromyelitis optica

Chloride imbalance between the serum and the cerebrospinal fluid (CSF) has been recently shown to exist in the acute phase of neuromyelitis optica (NMO). In this report, we studied the relation between the quotient of chloride (Q_Cl) and the severity of optic neuritis (ON) in NMO patients. There was a positive correlation (R = 0.67; p < 0.05) between Q_Cl and the length of ON-lesion. The visual prognosis also showed a positive correlation with Q_Cl in the acute phase (R = 0.58; p < 0.05). These results support the theory that chloride imbalance between serum and CSF may trigger the ON in NMO spectrum disorders.

Optic neuritis in paediatric patients: Experience over 27 years and a management protocol

INTRODUCTION AND OBJECTIVE

In this article, we present our experience on optic neuritis (ON) and provide a diagnostic/therapeutic protocol, intended to rule out other aetiologies (particularly infection), and a fact sheet for parents.

MATERIAL AND METHODS

We conducted a descriptive, retrospective study of patients with ON over a 27-year period (1990-2017). A review of the available scientific evidence was performed in order to draft the protocol and fact sheet.

RESULTS

Our neuropaediatrics department has assessed 20,744 patients in the last 27 years, of whom 14 were diagnosed with ON: 8 had isolated ON, 1 had multiple sclerosis (MS), 1 had clinically isolated syndrome (CIS), 3 had acute disseminated encephalomyelitis, and 1 had isolated ON and a history of acute disseminated encephalomyelitis one year previously. Patients' age range was 4-13 years; 50% were boys. Eight patients were aged over 10: 7 had isolated ON and 1 had MS. Nine patients had bilateral ON, and 3 had retrobulbar ON. MRI results were normal in 7 patients and showed involvement of the optic nerve only in 2 patients and optic nerve involvement + central nervous system demyelination in 5. Thirteen patients received corticosteroids. One patient had been vaccinated against meningococcus-C the previous month. Progression was favourable, except in the patient with MS. A management protocol and fact sheet are provided.

CONCLUSIONS

ON usually has a favourable clinical course. In children aged older than 10 years with risk factors for MS or optic neuromyelitis (hyperintensity on brain MRI, oligoclonal bands, anti-NMO antibody positivity, ON recurrence), the initiation of immunomodulatory treatment should be agreed with the neurology department. The protocol is useful for diagnostic decision-making, follow-up, and treatment of this rare disease with potentially major repercussions. The use of protocols and fact sheets is important.

Treatment of neuromyelitis optica with rituximab: a 2-year prospective multicenter study

OBJECTIVE

Neuromyelitis optica (NMO) is a very severe autoimmune disorder of the central nervous system. It affects young subjects and has a poor prognosis both on a functional and vital level. Therefore, it is imperative to reduce the frequency of relapses. The purpose of this study was to evaluate the clinical and neuroradiological effectiveness of rituximab (RTX) on active forms of NMO.

METHODS

We conducted a 2-year open prospective multicenter study that included 32 patients treated with RTX at a dose of 375 mg/m²/week for 1 month. When the number of circulating CD19+ B cells reached 1%, a maintenance therapy was started, consisting of two infusions of 1 g of RTX, administered at a 15-day interval. The primary objective was to reduce the annual relapse rate (ARR), in comparison to that observed in the 2 years before treatment onset.

RESULTS

Rituximab administration reduced the ARR from 1.34 to 0.56 (p = 0.0005). The average Expanded Disability Status Scale (EDSS) score significantly improved by 1.1 point, from 5.9 (2-9) to 4.8 (0-9) after 2 years (p = 0.03). Anti-aquaporin-4 antibodies' level predicted treatment failure (p = 0.03). Frequency of Gad+ lesions in spinal cord decreased from 23.3 to 14.2%. RTX treatment did not prevent the death of three patients (treatment failure in two patients and acute myeloid leukemia in a patient previously treated with mitoxantrone).

CONCLUSION

Rituximab is clinically effective in active forms of NMO, although few patients are resistant to the treatment.

Clinical Profile and Outcomes of Optic Neuritis in an HIV Prevalent Urban Community in South Africa

PURPOSE:

To determine the clinical profile, causes and response to corticosteroid therapy in patients admitted and treated for optic neuritis at a tertiary hospital in Cape Town, South Africa.

METHODS:

A retrospective case review of 117 patients with optic neuritis between January 2002 and December 2012. Demographic information, clinical presentation, course of illness, investigations performed and visual outcomes at discharge and at three month follow up were collected for analysis.

RESULTS:

60 of 117 patients (51%) had an identifiable secondary cause for optic neuritis. Of the 57 patients with idiopathic optic neuritis, 14 had features associated with demyelinating disease. HIV and syphilis accounted for 62% of secondary causes of optic neuritis. Presenting visual acuity of hand movements (HM) or worse and absence of pain with extra ocular movement were associated with poorer final visual outcomes in the idiopathic optic neuritis group.

CONCLUSION:

Optic neuritis in our patients, as elsewhere in Africa, tends to be atypical in presentation. A high proportion of patients have an identifiable secondary cause. These patients thus require more extensive investigation in order to identify causes which may influence management. Secondary optic neuritis and idiopathic atypical optic neuritis carry a poorer prognosis than typical demyelinating optic neuritis.

Neuromyelitis optica and neuromyelitis optica spectrum disorders

PURPOSE OF REVIEW

The discovery of highly specific auto-antibodies directed against the water channel aquaporin 4 was a quantum leap in the definition, classification and management of neuromyelitis optica (NMO). Herein, we propose an update on epidemiological, clinical and therapeutic advances in the field, underlining unmet needs.

RECENT FINDINGS

Large-scale epidemiological studies have recently provided a more precise evaluation of NMO prevalence and a better stratification regarding ethnicity and sex. New criteria have been proposed for so-called NMO spectrum disorders (NMOSD) and their relevance is currently being assessed. The identification of a new clinical entity associated to antibodies against myelin oligodendrocyte glycoprotein questions the border of NMOSD.

SUMMARY

The concept of NMOSD is opening a new era in clinical practice, allowing an easier and more homogeneous diagnosis and an increase in newly identified cases. This will facilitate clinical studies and support new therapeutic trial. Future researches should focus on the position of seronegative NMOSD and myelin oligodendrocyte glycoprotein-IgG disorders in the field and on promising strategies, including the immune tolerisation approaches, to eventually cure NMO.

Optic neuritis: the eye as a window to the brain

PURPOSE OF REVIEW

Acute optic neuritis is a common clinical problem, requiring a structured assessment to guide management and prevent visual loss. The optic nerve is the most accessible part of the central nervous system, so optic neuritis also represents an important paradigm to help decipher mechanisms of damage and recovery in the central nervous system. Important developments include the advent of optical coherence tomography as a biomarker of central nervous system axonal loss, the discovery of new pathological antibodies, notably against aquaporin-4 and, more recently, myelin oligodendrocyte protein, and emerging evidence for sodium channel blockade as a novel therapeutic approach to address energy failure in neuroinflammatory disease.

RECENT FINDINGS

We will present a practical approach to assessment of optic neuritis, highlighting the role of optical coherence tomography, when to test for new antibodies and the results of recent trials of sodium channel blockers.

SUMMARY

Optic neuritis remains a clinical diagnosis; increasingly optical coherence tomography is a key ancillary investigation. Patients with 'typical' optic neuritis, commonly a first presentation of multiple sclerosis, must be distinguished from 'atypical' optic neuritis, who require testing for new pathological antibodies and require more aggressive-targeted treatment. Sodium channel blockade is an emerging and novel potential therapeutic pathway in neuroinflammatory disease.

Neuromyelitis Optica (Devic's Syndrome): an Appraisal

Neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorders (NMOSD), previously known as Devic's syndrome, are a group of inflammatory disorders of the central nervous system (CNS) characterized by severe, immune-mediated demyelination and axonal damage, predominantly targeting optic nerves and the spinal cord typically associated with a disease-specific serum NMO-IgG antibody that selectively binds aquaporin-4 (AQP4). The classic and best-defined features of NMOSD include acute attacks of bilateral or rapidly sequential optic neuritis (leading to visual loss) or transverse myelitis (often causing limb weakness and bladder dysfunction) or both with a typically relapsing course. The diagnosis of NMO/NMOSD requires a consistent history and examination with typical clinical presentations, findings on spinal cord neuroimaging with MRI, cerebrospinal fluid analysis along with determination of AQP4-IgG serum autoantibody status, and exclusion of other disorders. Two major advances in this field has been the development of diagnostic criteria and treatment recommendations. Consensus diagnostic criteria have been established and were recently revised and published in 2015, enhancing the ability to make a diagnosis and appropriately evaluate these disorders. Expert recommendations and uncontrolled trials form the basis of treatment guidelines. All patients with suspected NMOSD should be treated for acute attacks as soon as possible with high-dose intravenous methylprednisolone -1 gram daily for three to five consecutive days and in some cases, plasma exchange should be used. It is recommended that every patient with NMOSD be started on an immunosuppressive agent, such as, azathioprine, methotrexate, or mycophenolate and in some cases, rituximab, soon after the acute attack and usually be treated for about 5 years after the attack. These advances have helped improve the prognosis and outcome in these disorders.

Pattern Recognition of the Multiple Sclerosis Syndrome

During recent decades, the autoimmune disease neuromyelitis optica spectrum disorder (NMOSD), once broadly classified under the umbrella of multiple sclerosis (MS), has been extended to include autoimmune inflammatory conditions of the central nervous system (CNS), which are now diagnosable with serum serological tests. These antibody-mediated inflammatory diseases of the CNS share a clinical presentation to MS. A number of practical learning points emerge in this review, which is geared toward the pattern recognition of optic neuritis, transverse myelitis, brainstem/cerebellar and hemispheric tumefactive demyelinating lesion (TDL)-associated MS, aquaporin-4-antibody and myelin oligodendrocyte glycoprotein (MOG)-antibody NMOSD, overlap syndrome, and some yet-to-be-defined/classified demyelinating disease, all unspecifically labeled under MS syndrome. The goal of this review is to increase clinicians’ awareness of the clinical nuances of the autoimmune conditions for MS and NMSOD, and to highlight highly suggestive patterns of clinical, paraclinical or imaging presentations in order to improve differentiation. With overlay in clinical manifestations between MS and NMOSD, magnetic resonance imaging (MRI) of the brain, orbits and spinal cord, serology, and most importantly, high index of suspicion based on pattern recognition, will help lead to the final diagnosis.

Prognostic factors and disease course in aquaporin-4 antibody-positive Chinese patients with acute optic neuritis

The objective is to assess the frequency of AQP4-Ab in Chinese patients with optic neuritis (ON) and to investigate the prognostic implications of AQP4-Ab seropositivity in such patients. The presence of aquaporin-4 (AQP4) antibodies in human AQP4-transfected cells was determined by indirect immunofluorescence, and the diagnostic and prognostic relevance of AQP4 antibodies in 215 Chinese patients with optic neuritis was evaluated. The patients were enrolled from the Chinese People's Liberation Army General Hospital (PLAGH) and followed up to 1-228 months. Kaplan-Meier survival analysis was used to investigate the visual outcomes and prognostic characteristics of 70 patients who were aquaporin-4 antibody seropositive, and altogether 115 eyes were involved. AQP4-Ab was detectable in 70/215 (32.6%) patients with acute monosymptomatic optic neuritis. These AQP4-Ab seropositive patients were diagnosed as sufferers of neuromyelitis optica (NMO) (n = 10), NMO spectrum disease (NMOSD) (n = 41), multiple sclerosis (MS) (n = 1), and acute optic neuritis (AON) (n = 18). Moreover, AQP4-Ab levels did not vary between seropositive AON and NMO-ON and did not correlate with disease severity. Finally, the male gender, older age at onset, number of relapses, concomitant autoimmune antibodies, and optic lesions in magnetic resonance imaging (MRI) were associated with the AQP4-Ab seropositive status and the risk of developing permanent visual disability. Acute optic neuritis has a higher incidence of anti-aquaporin-4 antibody in China than in Western countries, and AQP4 antibody is a sensitive and specific biomarker for discriminating NMO-ON from other types of optic neuritis during the early stage of the disease course.

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.

Differential diagnosis of neuromyelitis optica spectrum disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disorder of the central nervous system (CNS) mostly manifesting as optic neuritis and/or myelitis, which are frequently recurrent/bilateral or longitudinally extensive, respectively. As the autoantibody to aquaporin-4 (AQP4-Ab) can mediate the pathogenesis of NMOSD, testing for the AQP4-Ab in serum of patients can play a crucial role in diagnosing NMOSD. Nevertheless, the differential diagnosis of NMOSD in clinical practice is often challenging despite the phenotypical and serological characteristics of the disease because: (1) diverse diseases with autoimmune, vascular, infectious, or neoplastic etiologies can mimic these phenotypes of NMOSD; (2) patients with NMOSD may only have limited clinical manifestations, especially in their early disease stages; (3) test results for AQP4-Ab can be affected by several factors such as assay methods, serologic status, disease stages, or types of treatment; (4) some patients with NMOSD do not have AQP4-Ab; and (5) test results for the AQP4-Ab may not be readily available for the acute management of patients. Despite some similarity in their phenotypes, these NMOSD and NMOSD-mimics are distinct from each other in their pathogenesis, prognosis, and most importantly treatment. Understanding the detailed clinical, serological, radiological, and prognostic differences of these diseases will improve the proper management as well as diagnosis of patients.

Recurrent Longitudinally Extensive Myelitis and Aquaporin-4 Seronegativity - The Expanding Spectrum of Neuromyelitis Optica

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a recently proposed unifying term for Neuromyelitis Optica (NMO), also known as Devic's disease and related syndromes. It is a relapsing inflammatory demyelinating disease that most commonly affects optic nerves and the spinal cord, leading to sudden vision loss or weakness in one or both eyes, and loss of sensation and bladder function. Though inflammation may also involve the brain, the lesions seen in NMO are different from Multiple Sclerosis (MS) which has a similar clinical course. Attacks of NMOSD tend to be more severe and often different in nature from MS. MS and NMOSD are often confused but require a different course of treatment for optimal results. Here, we describe a patient who had clinical features suggestive of NMO but showed seronegativity for anti-aquaporin antibodies, done twice. Initially he was managed on the lines of MS but showed a deteriorating clinical course on initiation of treatment with interferons. Later, his diagnosis was revised to seronegative NMO and he was started on immunosuppressive therapy with azathioprine to which he showed optimal response and achieved disease stabilization.

What's new in neuromyelitis optica? A short review for the clinical neurologist

The evolution of neuromyelitis optica spectrum disorder (NMOSD) from a rare, incurable and misunderstood disease with almost universally poor outcomes to its present state in just over a decade is unprecedented in neurology and possibly in medicine. Our knowledge of NMOSD biology has led to the recognition of wider phenotypes, new disease mechanisms, and thus clinical trials of new and effective treatments. This article aims to update readers on the recent developments in NMOSD with particular emphasis on clinical advances, the 2015 diagnostic criteria, biomarkers, imaging, and therapeutic interventions.

Impact of the anti-aquaporin-4 autoantibody on inner retinal structure, function and structure-function associations in Japanese patients with optic neuritis

PURPOSE

An autoantibody against aquaporin-4 (AQP4 Ab) is highly specific for neuromyelitis optica spectrum disorder and plays a pathogenic role in this disease. The purpose of this study was to investigate the impact of AQP4 Ab on inner retinal structure, function, and the structure-function relationships in eyes with optic neuritis.

METHODS

Thirty five eyes from 25 cases who had received visual function tests and RTVue optical coherence tomography (OCT) measurement at least six months after the latest episode of optic neuritis were enrolled. Patients with multiple sclerosis were excluded. AQP4 Ab was measured using a cell-based assay. Visual acuity, mean deviation (MD) of the Humphrey visual field SITA standard 30-2 tests, retinal nerve fiber layer (RNFL), ganglion cell complex (GCC) thicknesses, and other clinical variables were compared between the AQP4 Ab-positive and -negative groups. Parameters associated with visual functions were evaluated by generalized estimating equation (GEE) models.

RESULTS

The AQP4 Ab-positive group (20 eyes from 12 cases) had a higher proportion of bilateral involvement and longer duration of follow-up than the AQP4 Ab-negative group (15 eyes from 13 cases). Linear mixed effect models revealed worse MD and visual acuity in AQP4 Ab-positive eyes than those in AQP4 Ab-negative eyes after adjusting for within-patient inter-eye dependence, whereas there were no differences in RNFL and GCC thickness between the two groups. In seropositive eyes, GEE regression analyses revealed that depending on age and the number of recurrences of ON episodes, OCT parameters correlated strongly with MD and more weakly with visual acuity.

CONCLUSIONS

Reductions in RNFL and GCC thickness were proportional to the visual field defect in eyes with AQP4 Ab but not in eyes without AQP4 Ab. The presence of AQP4 Ab probably plays a critical role in retinal ganglion cell loss in optic neuritis.

Role of low plasma volume treatment on clinical efficacy of plasmapheresis in neuromyelitis optica

BACKGROUND:

Neuromyelitis optica (NMO) is an autoimmune demyelinating disease preferentially targeting the optic nerves and spinal cord. Plasmapheresis (PP) is an effective adjunct therapy in severe NMO attacks. The recommended minimum plasma volume to be treated per session of PP is equivalent to total plasma volume (TPV) of the patient.

AIM:

To study the effect of lower plasma volume treated in patients with NMO on clinical efficacy of plasmapheresis in comparison to minimum recommended volume.

METHODS:

This retrospective study was done on acute NMO patients who were managed with PP at our center. Patients who had 5 sessions of PP, spread over 10 days, were included. Clinical outcome was defined as per predefined criteria.

RESULTS:

24 patients who underwent PP for acute NMO met our inclusion criteria. Females (age; mean (SD) 33.7 (11.2) years) were more common (n = 18). The minimum recommended plasma volume (PV) that was supposed to be treated per patient during entire acute therapeutic period was 195.5 (14.6) mL per kilogram-body-weight (kg-bw). We treated lower plasma volume (mean (SD) 112.7 (17.0) mL per kg-bw); the difference was significant (P < 0.05). The volume treated was same across the gender (P > 0.05). Significant clinical improvement was observed in 79% of patients (n = 19) after 6 months. There were no significant differences in volume of plasma treated, between patients who had moderate and marked improvement; also, who did, and did not have significant clinical improvement (P > 0.05; for both).

CONCLUSIONS:

Plasmapheresis is a safe and efficient add-on therapy in NMO, especially in steroid-resistant cases. Although the volumes of plasma treated during acute plasmapheresis were less than recommended minimum volumes, majority of patients had significant clinical improvement.

Valproic acid and ASK1 deficiency ameliorate optic neuritis and neurodegeneration in an animal model of multiple sclerosis

Optic neuritis, which is an acute inflammatory demyelinating syndrome of the central nervous system, is one of the major complications in multiple sclerosis (MS). Herein, we investigated the therapeutic potential of valproic acid (VPA) on optic neuritis in experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. EAE was induced in C57BL/6 mice by immunization with MOG_35-55 and VPA (300mg/kg) was administered via intraperitoneal injection once daily from day 3 postimmunization until the end of the experimental period (day 28). VPA treatment suppressed neuroinflammation and decreased the clinical score of EAE at an early phase (from day 12-14 after immunization). We also examined the effects of apoptosis signal-regulating kinase 1 (ASK1), an evolutionarily conserved signaling intermediate for innate immunity, in EAE mice. ASK1 deficiency strongly suppressed microglial activation and decreased the clinical score of EAE at a late phase (day 25, 27 and 28 after immunization). When VPA was administered to ASK1-deficient EAE mice, the clinical score was suppressed in both early and late phases (from day 12-28 after immunization) and showed synergistic effects on protection of retinal neurons. Our findings raise intriguing possibilities that the widely prescribed drug VPA and ASK1 inhibition may be useful for neuroinflammatory disorders including optic neuritis and MS.

Aquaporin-4 antibody titration in NMO patients treated with rituximab: A retrospective study

Objective:

We undertook an observational retrospective study to investigate the usefulness of aquaporin-4 (AQP4) antibodies (Ab) titration in the management of patients with neuromyelitis optica (NMO) treated with rituximab (RTX) by studying (1) the correlation between AQP4-Ab titer and disease activity, (2) the influence of RTX on antibody levels, and (3) the association between AQP4-Ab levels and responsiveness to RTX.

Methods:

A cell-based assay was used for AQP4-Ab titration in 322 serum samples from 7 patients with NMO treated with RTX (median follow-up 65 months), according to a treatment-to-target approach. Serum samples were collected every month following standardized procedures.

Results:

(1) In group analysis, AQP4-Ab titers correlated with the disease activity, showing higher titers during and preceding relapses than during remission. However, in individual analysis, an increase in AQP4-Ab titers and CD19+ B cells did not always precede a relapse. (2) A reduction of AQP4-Ab titers in the short-term and long-term period was observed during RTX treatment. (3) Reduction of AQP4-Ab titers was observed in responder patients both 3 months after RTX infusion and in the long-term follow-up. In one nonresponder patient, AQP4-Ab levels never decreased during the treatment period.

Conclusions:

Titration of AQP4-Abs could be useful in the clinical management of patients with NMO treated with RTX: titration before each reinfusion and 3 months after each reinfusion may provide information about responsiveness to RTX. Although a relationship among AQP4-Ab levels, disease activity, and response to RTX was observed, the usefulness of AQP4-Ab titration to predict relapses is limited.

The role of anti-aquaporin 4 antibody in the conversion of acute brainstem syndrome to neuromyelitis optica

Background

Acute brainstem syndrome (ABS) may herald multiple sclerosis (MS), neuromyelitis optica (NMO), or occur as an isolated syndrome. The aquaporin 4 (AQP4)-specific serum autoantibody, NMO-IgG, is a biomarker for NMO. However, the role of anti-AQP4 antibody in the conversion of ABS to NMO is unclear.

Methods

Thirty-one patients with first-event ABS were divided into two groups according to the presence of anti-AQP4 antibodies, their clinical features and outcomes were retrospectively analyzed.

Results

Fourteen of 31 patients (45.16 %) were seropositive for NMO-IgG. The 71.43 % of anti-AQP4 (+) ABS patients converted to NMO, while only 11.76 % of anti-AQP4 (-) ABS patients progressed to NMO. Anti-AQP4 (+) ABS patients demonstrated a higher IgG index (0.68 ± 0.43 vs 0.42 ± 0.13, p < 0.01) and Kurtzke Expanded Disability Status Scale (4.64 ± 0.93 vs 2.56 ± 0.81, p < 0.01) than anti-AQP4 (-) ABS patients. Area postrema clinical brainstem symptoms occurred more frequently in anti-AQP4 (+) ABS patients than those in anti-AQP4 (-) ABS patients (71.43 % vs 17.65 %, p = 0.004). In examination of magnetic resonance imaging (MRI), the 78.57 % of anti-AQP4 (+) ABS patients had medulla-predominant involvements in the sagittal view and dorsal-predominant involvements in the axial view.

Conclusions

ABS represents an inaugural or limited form of NMO in a high proportion of anti-AQP4 (+) patients.

Clinical Features and Visual Outcomes of Optic Neuritis in Chinese Children

Purpose. Although optic neuritis (ON) in children is relatively common, visual outcomes and factors associated with the condition have not been well documented. The aim of this study was to evaluate the clinical features and visual outcomes of ON in Chinese children. Methods. Patients with a first episode of ON at a tertiary neuroophthalmic centre in China were assessed and followed up for at least three months. Visual outcomes and clinical, laboratory, and neuroimaging findings were reviewed. In patients with bilateral ON, only the eyes with worse visual acuity (VA) at presentation were used for statistical analysis. Results. Seventy-six children (76 eyes) with a first episode of ON were included. The mean age was 11.8 years, 60.5% were females, and 48.7% had bilateral involvement. The children were followed up for an average of 18.5 months (age range, 3-48 months). Vision loss at presentation was severe, with VA < 20/200 in 37 eyes (48.7%). At the final visit, 3 (3.9%) eyes had VA of at least 20/20, and 41 (53.9%) eyes had VA of at least 20/40. The final VA in 35 eyes (46.1%) was worse than 20/40. Children aged ≤ 10 years had better predicted visual outcomes when compared to children over 10 years (odds ratio = 2.73, 95% confidential interval: 1.05-7.07, and P = 0.039). The other features of this cohort, such as sex, experienced bilateral attack, VA at presentation, presence of optic disc edema, systemic diseases, magnetic resonance imaging (MRI) findings, and aquaporin-4 (AQP-4) antibody status, were not significantly correlated with the final visual outcome. Conclusion. The data revealed the clinical characteristics and visual outcomes of ON in Chinese children. ON in children was associated with severe vision loss and relatively good visual recovery. The age at onset could predict the final visual function.

Aquaporin 4 Antibody in the Korean Patient with New-Onset Optic Neuritis

PURPOSE

To evaluate the prevalence of aquaporin 4 antibody (AQP4-Ab) in new-onset optic neuritis patients and investigate the characteristics of seropositive patients.

METHODS

Thirty-six women and six men with new-onset isolated optic neuritis were included in this study between January 2013 and December 2014. AQP4-Ab was detected and all blood samples were obtained prior to treatment and within one week from attack. The patients were sub-grouped into either a seropositive group or a seronegative group according to AQP4-Ab. Differences in age, gender, initial visual acuity, and final visual acuity between groups were analyzed.

RESULTS

Six (14.3%) of these patients (five women and one man) exhibited AQP4-Ab. There was no significant difference in mean age between study groups (positive group: 38.7 ± 11.5 years, negative group: 42.3 ± 14.7 years, P=0.548). Bilateral simultaneous involvement was more common in seropositive patients than in seronegative patients (occurred in two out of six seropositive patients and in one out of 36 seronegative patients, P = 0.007). With regards to poor visual outcome (worse than 1.0 LogMAR), seropositive patients exhibited more severe visual loss than seronegative patients. None of the seropositive patients exhibited myelitis symptoms during the follow-up period (mean follow-up period: 8-32 months).

CONCLUSION

The prevalence of AQP4 antibody was often detected in new-onset optic neuritis patients. In patients with bilateral involvement or poor initial visual acuity, the AQP4 antibody test should be considered.

Multicentre comparison of a diagnostic assay: aquaporin-4 antibodies in neuromyelitis optica

OBJECTIVE

Antibodies to cell surface central nervous system proteins help to diagnose conditions which often respond to immunotherapies. The assessment of antibody assays needs to reflect their clinical utility. We report the results of a multicentre study of aquaporin (AQP) 4 antibody (AQP4-Ab) assays in neuromyelitis optica spectrum disorders (NMOSD).

METHODS

Coded samples from patients with neuromyelitis optica (NMO) or NMOSD (101) and controls (92) were tested at 15 European diagnostic centres using 21 assays including live (n=3) or fixed cell-based assays (n=10), flow cytometry (n=4), immunohistochemistry (n=3) and ELISA (n=1).

RESULTS

Results of tests on 92 controls identified 12assays as highly specific (0-1 false-positive results). 32 samples from 50 (64%) NMO sera and 34 from 51 (67%) NMOSD sera were positive on at least two of the 12 highly specific assays, leaving 35 patients with seronegative NMO/spectrum disorder (SD). On the basis of a combination of clinical phenotype and the highly specific assays, 66 AQP4-Ab seropositive samples were used to establish the sensitivities (51.5-100%) of all 21 assays. The specificities (85.8-100%) were based on 92 control samples and 35 seronegative NMO/SD patient samples.

CONCLUSIONS

The cell-based assays were most sensitive and specific overall, but immunohistochemistry or flow cytometry could be equally accurate in specialist centres. Since patients with AQP4-Ab negative NMO/SD require different management, the use of both appropriate control samples and defined seronegative NMOSD samples is essential to evaluate these assays in a clinically meaningful way. The process described here can be applied to the evaluation of other antibody assays in the newly evolving field of autoimmune neurology.

Optic neuritis: a 5-year follow-up study of Chinese patients based on aquaporin-4 antibody status and ages

Little work has been performed on the long-term outcome of optic neuritis (ON) according to the status of aquaporin-4 antibody (AQP4-Ab) and long-term prognosis in older patients in China. This study retrospectively analyzed medical records in a cohort of Chinese patients with 5-year follow-up according to AQP4-Ab status and ages from January 2009 to December 2010. The clinical features, laboratory findings and risk factors for prognosis were analyzed. A total of 128 ON patients were included, 66.4 % of whom were female. The median age at onset was 36.8 years (range 18-73). Serum AQP4-Ab was positive in 45 (35.2 %) patients, with greater frequency in the female, bilateral, and recurrent ON groups (48.2, 42.5 and 53.6 %, respectively). Seropositive AQP4-Ab ON patients had worse visual recovery compared to seronegative patients (p = 0.033). The average and four quadrants of retinal nerve fiber layer (RNFL) thickness were significantly thinner in the seropositive group than in the seronegative group (p < 0.05). At 5-year follow-up, the ON recurrence rate was higher in the seropositive AQP4-Ab patients (37/45, 82.3 %) than in the seronegative patients (35/83, 42.2 %, p < 0.001). Among the seropositive patients, 40 % (18/45) developed neuromyelitis optica (NMO). Only 1.2 % (1/83) of the seronegative patients developed NMO and 4.8 % (4/83) developed to MS. Further, the multivariate analysis in seropositive AQP4-Ab patients showed that two risk factors for transverse myelitis (TM) episode were ocular pain and recurrence within 1 year. The older patients had worse visual outcome after the first episode of ON than the younger patients (p = 0.007). However, the two groups did not differ significantly with regard to prevalence of AQP4-Ab, long-term visual recovery and the risk of developing to NMO/MS.

Neuromyelitis Optica Spectrum Disorder Associated With Autoimmune Hemolytic Anemia and Lymphoma

Neuromyelitis optica (NMO) is an inflammatory demyelinating disorder characterized by monophasic or recurrent attacks of optic neuritis (ON) and transverse myelitis. NMO spectrum disorders include patients who are seropositive for NMO-IgG antibody and have experienced at least 1 demyelinating attack. NMO has been associated with other autoimmune conditions. We describe a patient diagnosed with autoimmune hemolytic anemia and marginal zone lymphoma, who later developed NMO-IgG seropositive ON. The coexistence of multiple immunologic abnormalities in this patient points to a generalized dysfunction of the humoral immune system. History of autoimmunity should alert the clinician to the possibility of NMO spectrum disorder in a patient presenting with isolated ON.

Subclinical primary retinal pathology in neuromyelitis optica spectrum disorder

Foveal thickness may be a more sensitive indicator of primary retinal pathology than retinal nerve fiber layer thickness since the fovea contains no or sparse retinal nerve fiber layer, which coalesces into axons of the optic nerve. To our knowledge, few quantitative in vivo studies have investigated foveal thickness. By using optical coherence tomography, we measured foveal thickness to evaluate intrinsic retinal pathology. Seventy-two neuromyelitis optica spectrum disorder patients (99 eyes with optic neuritis and 45 eyes without optic neuritis) and 34 age-matched controls were included. Foveal thinning was observed both in eyes with non-optic neuritis (185.1 µm, p < 0.001) and optic neuritis (185.0 µm, p < 0.001) relative to controls (205.0 µm). Compared to controls, eyes with non-optic neuritis did not have peripapillary retinal nerve fiber layer thinning, but showed foveal thinning (p < 0.001). In neuromyelitis optica spectrum disorder, foveal thickness correlated with 2.5 % low contrast visual acuity, while retinal nerve fiber layer thickness correlated with high or low contrast visual acuity, extended disability status scale, and disease duration. In this study, we observed foveal thinning irrespective of optic neuritis; thus, we believe that subclinical primary retinal pathology, prior to retinal nerve fiber layer thinning, may exist in neuromyelitis optica spectrum disorder.

Treatment of neuromyelitis optica

PURPOSE OF REVIEW

Neuromyelitis optica (NMO) is an antibody-mediated inflammatory disease of the central nervous system with a predilection for the optic nerves, spinal cord and certain brain regions. It has a distinct pathogenesis relating to aquaporin-4 autoimmunity and complement-mediated injury. This knowledge has translated into targeted efforts to develop novel, disease-specific treatments. In this review, we discuss evidence supporting the use of currently available treatments for acute exacerbations and for long-term disease modification. We also discuss the risks and benefits of available and emerging immunotherapies.

RECENT FINDINGS

Early, accurate diagnosis of NMO with appropriate acute and long-term immunosuppressive treatment is of prime importance for the prevention of disability associated with this disease. Standard measures for the management of acute exacerbations include intravenous methylprednisolone and plasmapheresis. First-line, long-term immunotherapies for NMO include azathioprine, mycophenolate mofetil and rituximab. Three randomized controlled treatment trials evaluating these agents are currently being conducted. In addition, there are numerous emerging therapies that are based upon current understanding of the disease immunopathogenesis.

SUMMARY

NMO is an autoimmune disease that is separate from multiple sclerosis. Better understanding of its antibody and complement-dependent pathophysiology has proven to be critical for the formulation of current and future treatment strategies.

Longitudinally extensive optic neuritis as an MRI biomarker distinguishes neuromyelitis optica from multiple sclerosis

OBJECTIVE

To differentiate MRI characteristics of optic neuritis associated with neuromyelitis optica (NMO) and relapsing remitting multiple sclerosis (RRMS).

BACKGROUND

Optic neuritis is a common presenting feature of both neuromyelitis optica and multiple sclerosis. Distinguishing between NMO and RRMS is important in guiding treatment, but biomarkers of NMO and MS can be absent early in the disease process. We looked for differences in MRI characteristics of optic neuritis associated with NMO and MS that provide an early clue in the diagnostic workup.

DESIGN/METHODS

We conducted a retrospective analysis of 26 NMO and 26 RRMS patients presenting to the Johns Hopkins Hospital with MRI-confirmed acute optic neuritis. MRIs were assessed to identify the location and longitudinal extent of each contrast enhancing lesion. For the purposes of this study, the optic nerve was divided into intraorbital, canalicular, pre-chiasmal, chiasmal, and optic tract.

RESULTS

There are distinct differences in MRI characteristics between NMO- and RRMS-associated optic neuritis. The majority of NMO lesions were longitudinally extensive measuring at least 17.6mm in length and involving at least three optic nerve segments. At a cutoff of 17.6mm lesion length, the specificity for NMO is 76.9% with a sensitivity of 80.8% and positive likelihood ratio of 3.50. Conversely, MS lesions were more commonly focal in one optic nerve segment localized anteriorly.

CONCLUSIONS

Optic neuritis in NMO has a distinct pattern on MRI as compared with RRMS and can help differentiate these two neuroinflammatory diseases at presentation.

Update on biomarkers in neuromyelitis optica

Neuromyelitis optica (NMO) (and NMO spectrum disorder) is an autoimmune inflammatory disease of the CNS primarily affecting spinal cord and optic nerves. Reliable and sensitive biomarkers for onset, relapse, and progression in NMO are urgently needed because of the heterogeneous clinical presentation, severity of neurologic disability following relapses, and variability of therapeutic response. Detecting aquaporin-4 (AQP4) antibodies (AQP4-IgG or NMO-IgG) in serum supports the diagnosis of seropositive NMO. However, whether AQP4-IgG levels correlate with disease activity, severity, response to therapy, or long-term outcomes is unclear. Moreover, biomarkers for patients with seronegative NMO have yet to be defined and validated. Collaborative international studies hold great promise for establishing and validating biomarkers that are useful in therapeutic trials and clinical management. In this review, we discuss known and potential biomarkers for NMO.

Neuromyelitis optica and neuromyelitis optica spectrum disorder: Natural history and long-term outcome, an Indian experience

Background:

Neuromyelitis optica (NMO) has evolved from devic's classical description to a broader disease spectrum, from monophasic illness to a polyphasic illness with multiple recurrences, disease confined to optic nerve and spinal cord to now brain stem, cerebrum and even endocrinopathy due to hypothalamic involvement.

Objectives:

To report, the epidemiological characteristics, clinical presentations, recurrence rate, treatment and response to therapy in 26 patients with NMO and NMO spectrum disorder among the Indian population.

Methods:

We performed observational, retrospective analysis of our prospectively maintained data base of patients with NMO, longitudinally extensive transverse myelitis during the period of January 2003–December 2012 who satisfied the national multiple sclerosis society (NMSS) task force criteria for diagnosis of NMO and NMO spectrum disorder.

Results:

There were 26 patients (female: male, 21:5), the mean age of onset of symptom was 27 years (range 9–58, standard deviation = 12). Twenty-one patients (80%) fulfilled NMSS criteria for NMO while rest 5 patients (20%) were considered as NMO spectrum disorder. Seven patients (27%) had a monophasic illness, 19 patients (73%) had a polyphasic illness with recurrences. The Median recurrence rate was 4/patient in the polyphasic group. 13 (50%) patient were tested for aquaporin 4 antibody, 8 (61%) were positive while 5 patients (39%) were negative. All patients received intravenous methyl prednisolone, 9 patients (35%) required further treatment for acute illness in view of unresponsiveness to steroids. Thirteen patients (50%) received disease-modifying agents for recurrences. Mean duration of follow-up was 5 years. All patients had a good outcome (modified Rankin scale, <3) except one who had poor visual recovery.

Conclusion:

Neuromyelitis optica/NMO spectrum disorder is demyelinating disorder with female predominance, polyphasic course, myelitis being most common event although brain stem involvement is not uncommon with NMO antibody positivity in 60% patients, confirms the literature data.

International consensus diagnostic criteria for neuromyelitis optica spectrum disorders

Neuromyelitis optica (NMO) is an inflammatory CNS syndrome distinct from multiple sclerosis (MS) that is associated with serum aquaporin-4 immunoglobulin G antibodies (AQP4-IgG). Prior NMO diagnostic criteria required optic nerve and spinal cord involvement but more restricted or more extensive CNS involvement may occur. The International Panel for NMO Diagnosis (IPND) was convened to develop revised diagnostic criteria using systematic literature reviews and electronic surveys to facilitate consensus. The new nomenclature defines the unifying term NMO spectrum disorders (NMOSD), which is stratified further by serologic testing (NMOSD with or without AQP4-IgG). The core clinical characteristics required for patients with NMOSD with AQP4-IgG include clinical syndromes or MRI findings related to optic nerve, spinal cord, area postrema, other brainstem, diencephalic, or cerebral presentations. More stringent clinical criteria, with additional neuroimaging findings, are required for diagnosis of NMOSD without AQP4-IgG or when serologic testing is unavailable. The IPND also proposed validation strategies and achieved consensus on pediatric NMOSD diagnosis and the concepts of monophasic NMOSD and opticospinal MS.

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

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

The Correlation between Aquaporin-4 Antibody and the Visual Function of Patients with Demyelinating Optic Neuritis at Onset

ON patients with AQP4-Ab seropositivity tend to be predominantly female and young and have worse visual acuity and more severe damage to their visual fields compared with AQP4-Ab seronegativity.

Antibodies to aquaporin 4, myelin-oligodendrocyte glycoprotein, and the glycine receptor α1 subunit in patients with isolated optic neuritis

IMPORTANCE

In patients with isolated optic neuritis (ON), the presence of antibodies to aquaporin 4 (AQP4) has diagnostic and prognostic value. In the same clinical setting, the significance of antibodies to myelin-oligodendrocyte glycoprotein (MOG) or the glycine receptor α1 subunit (GlyR) is unclear.

OBJECTIVES

To investigate the frequency of antibodies to AQP4, MOG, and GlyR in patients with unilateral or bilateral, severe, or recurrent isolated ON and to determine their clinical and prognostic correlates.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective case-control study from November 1, 2005, through May 30, 2014 with the detection of autoantibodies in a neuroimmunology referral center. We included 51 patients with ON but without clinical and magnetic resonance imaging findings outside the optic nerves and 142 controls (30 healthy individuals, 48 patients with neuromyelitis optica, and 64 patients with multiple sclerosis).

MAIN OUTCOMES AND MEASURES

Clinicoimmunologic analysis. We determined the presence of antibodies to AQP4, MOG, and GlyR using cell-based assays.

RESULTS

The median age of the patients at the onset of ON symptoms was 28 (range, 5-65) years; 36 patients (71%) were female. Antibodies were identified in 23 patients (45%), including MOG in 10 patients, AQP4 in 6 patients, and GlyR in 7 patients (concurrent with MOG in 3 and concurrent with AQP4 in 1). Patients with AQP4 antibodies (median visual score, 3.5 [range, 1-9]) had a worse visual outcome than patients with MOG antibodies alone (median visual score, 0 [range, 0-5]; P = .007), patients with seronegative findings (n = 28) (median visual score, 1.0 [range, 0-14]; P = .08), and patients with GlyR antibodies alone (n = 3) (median visual score, 0 [range, 0-2]; P = .10).The median age of the 7 patients with GlyR antibodies was 27 (range, 11-38) years; 5 (71%) of these were female. Among the 3 patients with GlyR antibodies alone, 1 patient had monophasic ON, 1 had recurrent isolated ON, and 1 had conversion to multiple sclerosis. The 3 patients with GlyR antibodies concurrent with MOG antibodies had recurrent isolated ON, and the patient with concurrent AQP4 antibodies had conversion to neuromyelitis optica. Of the 48 controls with neuromyelitis optica, 37 (77%) had AQP4 antibodies, 4 (8%) had MOG antibodies, 2 (4%) had AQP4 antibodies concurrent with MOG antibodies, and 5 (10%) were seronegative. Of the 64 controls with multiple sclerosis, 5 (8%) had GlyR antibodies.

CONCLUSIONS AND RELEVANCE

Forty-five percent of patients with unilateral or bilateral, severe, or recurrent isolated ON had antibodies to MOG, AQP4, or GlyR. Patients with AQP4 antibodies had the poorest visual outcomes, whereas patients with MOG antibodies had a better outcome that was similar to that of patients with seronegative findings. The significance of GlyR antibodies in the setting of ON is unclear and deserves further study.

MRI characteristics of neuromyelitis optica spectrum disorder: an international update

Since its initial reports in the 19th century, neuromyelitis optica (NMO) had been thought to involve only the optic nerves and spinal cord. However, the discovery of highly specific anti-aquaporin-4 antibody diagnostic biomarker for NMO enabled recognition of more diverse clinical spectrum of manifestations. Brain MRI abnormalities in patients seropositive for anti-aquaporin-4 antibody are common and some may be relatively unique by virtue of localization and configuration. Some seropositive patients present with brain involvement during their first attack and/or continue to relapse in the same location without optic nerve and spinal cord involvement. Thus, characteristics of brain abnormalities in such patients have become of increased interest. In this regard, MRI has an increasingly important role in the differential diagnosis of NMO and its spectrum disorder (NMOSD), particularly from multiple sclerosis. Differentiating these conditions is of prime importance because early initiation of effective immunosuppressive therapy is the key to preventing attack-related disability in NMOSD, whereas some disease-modifying drugs for multiple sclerosis may exacerbate the disease. Therefore, identifying the MRI features suggestive of NMOSD has diagnostic and prognostic implications. We herein review the brain, optic nerve, and spinal cord MRI findings of NMOSD.

Aquaporin 4 antibody [NMO Ab] status in patients with severe optic neuritis in India

Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system that causes attacks of optic neuritis and transverse myelitis. The discovery of a specific serum marker for NMO-IgG antibody [aquaporin 4 antibody/AQP4 Ab] has revolutionised the treatment of demyelinating diseases. Severe vision loss can be seen in optic neuritis (ON) associated with both multiple sclerosis (MS) and NMO. Identifying this antibody in optic neuritis patients can help us to establish the likelihood of these patients developing NMO (Jarius et al. Neurol Sci 298:158-162, 2010). It is important to differentiate these two entities as the treatment strategies of MS and NMO are different. To the best of our knowledge, there is no published literature regarding the importance of identifying this antibody in severe optic neuritis in Indian patients. Hence we decided to screen our severe optic neuritis patients for this AQP4 Ab. To investigate the presence of aquaporin 4 antibody and determine its prognostic value for visual and neurological outcome, in patients with bilateral and recurrent [severe] ON without any previous neurological manifestations presenting to a neuro-ophthalmology clinic in India. Single centre, prospective study. 40 patients (27 female patients and 13 male) with severe optic neuritis [patients with no visual improvement by 4 weeks from onset of vision loss] who presented either as recurrent attacks or as bilateral and severe optic neuritis between January 2010 and June 2011 were enrolled. Clinical features, visual outcome and sequential neurological events were compared between the seropositive and the seronegative groups. Aquaporin 4 antibodies were detected from serum using ELISA technique and IIF technique. Presence of this antibody in the serum was considered to be seropositive status and patients who did not have this antibody were considered seronegatives. AQP4 antibodies were detected in 8 of the 40 patients with severe ON (20 %).The female to male ratio in the seropositive group was 8:0. The NMO antibody titer ranged from 0.3 to 760 U/ml. ANA positivity in seropositive patients was statistically significant (p = 0.043). All seropositive patients had significantly poorer visual outcome as compared with the seronegative patients (p = 0.04).