Lower frequency of antibodies to MOG in Brazilian patients with demyelinating diseases: An ethnicity influence?

Clinical spectrum of myelin oligodendrocyte glycoprotein antibody-associated disease in Brazil: a single-center experience

BACKGROUND

 Anti-myelin oligodendrocyte glycoprotein (anti-MOG) antibody-associated disease (MOGAD) is an immune-mediated neurological disorder with a broad spectrum of clinical presentation that is often difficult to distinguish from other demyelinating diseases, such as multiple sclerosis and neuromyelitis optica spectrum disorder.

OBJECTIVE

 To describe the clinical and paraclinical characteristics of MOGAD in a Brazilian tertiary center.

METHODS

 We retrospectively reviewed the records of adult and pediatric patients who tested positive for anti-MOG antibodies and presented with clinical and radiological diseases compatible with MOGAD.

RESULTS

 Forty-one patients (10 children) were included: 56% female, 58% Caucasian, mean age at onset 31 years (range 6-64), with a mean disease duration of 59.6 months (range 1-264 months). The most frequent onset presentation was optic neuritis (68%), acute disseminated encephalomyelitis (ADEM, 12%), and myelitis (10%). A monophasic disease course was observed in 49%. EDSS median was 2.1 at the last visit. Most patients (83%) were under continuous immunosuppressive treatment. Azathioprine was the first-line treatment in 59%. In all ADEM cases, conus, and root involvement was radiologically observed on MRI.

CONCLUSION

 Brazilian MOGAD patients presented with a similar spectrum of previously reported MOGAD phenotypes. Conus and spinal root involvement seems to be frequently present in MOGAD-ADEM and could serve as radiologic characteristics of this clinical entity.

Seroprevalence of MOG and AQP4 Antibodies and Outcomes in an Indian Cohort of Pediatric Acquired Demyelinating Syndromes

This study aimed to determine the seropositivity of myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) and aquaporin-4 antibodies (AQP4-Ab) and outcomes in children with acquired demyelinating syndromes (ADSs). Children (6 months-15 years) with suspected ADS were enrolled and tested for MOG-Ab and AQP4-Ab prospectively over 18 months at a tertiary care hospital in North India. Children with proven nonimmune-mediated neurological disorders were enrolled as controls. Of 79 children with suspected ADS, 66 were enrolled. Among the enrolled children with ADS, acute demyelinating encephalomyelitis (ADEM) (25) was the most common first clinical event followed by optic neuritis (ON) (20) and transverse myelitis (TM) (19; one child had ON and TM simultaneously [neuromyelitis optica spectrum disorders [NMOSDs]]), while two children had clinically isolated syndrome (CIS) apart from ON and TM. Fourteen (21.2%, confidence interval [CI] 11.3-31.1) tested positive for one antibody (12 [18.1%; 95% CI 10.5-25.5%] for MOG-Ab and 2 [3%; 95% CI 0-7.2%] for AQP4-Ab). None of the 62 controls tested positive for any antibody. The final diagnosis in those with the monophasic ADS was ADEM (21), ON (13), TM (16), and other CIS (1) while that in children with recurrent events was multiphasic disseminated encephalomyelitis (MDEM) (2), NMOSD (3), ADEM-ON (4), recurrent ON (4), and MS (2). Among those with the first event, 4/51 (7.8%; 95% CI 0.5-15.2%) were MOG-Ab positive and 2 AQP4-Ab positive, whereas 8/15 (53.3% [95% CI 28.1-78.6%]) with recurrent events (MDEM [2], ADEM-ON [4], recurrent ON [1], and recurrent TM [1]) were MOG-Ab positive. Hence, MOG-Abs are the most common antibodies detected in one in five children with pediatric ADS, especially in relapsing disease. AQP4-Abs are rare in children with ADS.

Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD): A Review of Clinical and MRI Features, Diagnosis, and Management

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is the most recently defined inflammatory demyelinating disease of the central nervous system (CNS). Over the last decade, several studies have helped delineate the characteristic clinical-MRI phenotypes of the disease, allowing distinction from aquaporin-4 (AQP4)-IgG-positive neuromyelitis optica spectrum disorder (AQP4-IgG+NMOSD) and multiple sclerosis (MS). The clinical manifestations of MOGAD are heterogeneous, ranging from isolated optic neuritis or myelitis to multifocal CNS demyelination often in the form of acute disseminated encephalomyelitis (ADEM), or cortical encephalitis. A relapsing course is observed in approximately 50% of patients. Characteristic MRI features have been described that increase the diagnostic suspicion (e.g., perineural optic nerve enhancement, spinal cord H-sign, T2-lesion resolution over time) and help discriminate from MS and AQP4+NMOSD, despite some overlap. The detection of MOG-IgG in the serum (and sometimes CSF) confirms the diagnosis in patients with compatible clinical-MRI phenotypes, but false positive results are occasionally encountered, especially with indiscriminate testing of large unselected populations. The type of cell-based assay used to evaluate for MOG-IgG (fixed vs. live) and antibody end-titer (low vs. high) can influence the likelihood of MOGAD diagnosis. International consensus diagnostic criteria for MOGAD are currently being compiled and will assist in clinical diagnosis and be useful for enrolment in clinical trials. Although randomized controlled trials are lacking, MOGAD acute attacks appear to be very responsive to high dose steroids and plasma exchange may be considered in refractory cases. Attack-prevention treatments also lack class-I data and empiric maintenance treatment is generally reserved for relapsing cases or patients with severe residual disability after the presenting attack. A variety of empiric steroid-sparing immunosuppressants can be considered and may be efficacious based on retrospective or prospective observational studies but prospective randomized placebo-controlled trials are needed to better guide treatment. In summary, this article will review our rapidly evolving understanding of MOGAD diagnosis and management.

Differential diagnosis of demyelinating diseases: what's new?

BACKGROUND

Acquired demyelinating disorders lead to overlapping visual, pyramidal, sensory, autonomic, and cerebellar deficits and may lead to severe disability. Early diagnosis and start of treatment are fundamental towards preventing further attacks and halting disability.

OBJECTIVE

In this paper we provide an updated overview of the differential diagnoses of acquired demyelinating disorders.

METHODS

We performed a critical targeted review of the diagnoses of the most prevalent demyelinating disorders: multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD).

RESULTS

We discuss the workup, diagnostic criteria and new biomarkers currently being used for the diagnosis of these disease entities taking into account the particularities of the Brazilian population and healthcare system.

CONCLUSION

A comprehensive analysis of medical history, physical examination, biomedical and imaging data should be performed to obtain differential diagnosis. Diagnostic criteria should be mindfully employed considering ethnic and environmental particularities of each patient.

Optic neuritis in Asian type opticospinal multiple sclerosis (OSMS-ON) in a non-Asian population: A functional-structural paradox

BACKGROUND

Biomarkers have improved the classification of autoimmune inflammatory disorders, including optic neuritis (ON) as a frequent presentation of multiple sclerosis, neuromyelitis spectrum disorders, MOG antibody-related disease (MOGAD), and opticospinal multiple sclerosis (OSMS). The phenotype of OSMS in non-Asian populations is less well known.

OBJECTIVE

We investigated the clinical features and prognosis of OSMS-ON in a Brazilian cohort.

METHODS

This was a single-center cohort study of patients from Rio de Janeiro (Brazil) with OSMS. All individuals were MOG- and AQP4-seronegative, clinically diagnosed with ON, and had magnetic resonance imaging-confirmed transverse myelitis (TM). Subjects and healthy controls (HCs) were assessed for visual acuity (logMAR VA), automated perimetry mean deviation (MD), intraocular pressure, and spectral-domain optical coherence tomography (OCT), followed by automated retinal layer segmentation of the peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell and inner plexiform layer (mGCIPL). Receiver operator characteristic curves were plotted and the area under the curve (AUC) was calculated for group comparisons of retinal asymmetry of the pRNFL and mGCIPL.

RESULTS

The 30 patients with OSMS were predominantly female and white. The mean age was 48 years (range 20-70 years). Unilateral ON was the index event in 83.3% of patients. Over the average 18-year follow-up period, there were 89 relapses of ON. In individuals with OSMS, the average VA was 0.07±0.14 in the right eye (RE) and 0.13±0.30 in the left eye (LE). The MD was -5.37±5.88 dB and -5.23±3.34 dB for the RE and LE, respectively. There was a significant cumulative loss of VA (p = 0.0003) and MD (p = 0.0001) with a higher number of recurrent episodes. Atrophy of the pRNFL thickness was significant in OSMS (RE, 78.62 ± 16.01 µm; LE, 79.86 ± 13.79 µm) relative to the HC group (RE, 98.87 ± 10.68 µm; LE, 97.87 ± 10.85 µm, p = 0.0001). Likewise, there was significant mGCIPL atrophy in patients with OSMS (RE, 74.96 ± 14.46 µm; LE, 73.88 ± 13.79 µm) relative to the HC group (RE, 90.50 ± 6.74 µm; LE, 90.41± 6.89 µm; p = 0.0001). Retinal asymmetry, inter-eye percentage, and absolute differences accurately separated patients with unilateral ON from HCs (AUC=0.89 and AUC=0.85, respectively).

CONCLUSION

A structural-functional paradox was found in OSMS with a high diagnostic value for a novel metric based on retinal asymmetry. The functional visual outcome are excellent despite significant structural damage to the inner retinal layers in patients with a high ON relapse rate and long-term bilateral sequential involvement.

[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.

The occurrence of myelin oligodendrocyte glycoprotein antibodies in aquaporin-4-antibody seronegative Neuromyelitis Optica Spectrum Disorder: A systematic review and meta-analysis

BACKGROUND

Despite inclusion in neuromyelitis optica spectrum disorders (NMOSD), myelin oligodendrocyte glycoprotein antibody (MOG-Ab)-associated diseases are increasingly recognized as an independent disease entity. In this study, we conducted a systematic review and meta-analysis to comprehensively update the rate of occurrence of MOG-Ab in Aquaporin4 (AQP4)-antibody seronegative NMOSD.

METHODS

We searched PubMed, EMBASE, and Cochrane databases for studies reporting the rates of patients with MOG-Ab in NMOSD. Fixed or random-effects models were used to pool results across studies.

RESULTS

Fourteen studies met the inclusion criteria. Overall, MOG-Abs positive patients comprised 9.3% of all NMO/NMOSD (95% confidence interval [CI] 7.9%-10.8%, I² = 13.1%), 32.5% of all AQP4-Ab seronegative NMO/NMOSD (95% CI 25.7%-39.3%, I² = 45.8%), and 41.6% of AQP4-Ab seronegative NMOSD cases diagnosed by IPND 2015 criteria (95% CI 35.1%-48.2%, I² = 0.0%). The pooled prevalence of MOG-Ab was 31.0% among Asian AQP4-Ab seronegative NMO/NMOSD patients (95% CI 22.1%-39.9% I²=54.1%) and 34.3% in European seronegative NMO/NMOSD (95% CI 21.9%-46.7%, I² = 51.9%).

CONCLUSIONS

This study shows that MOG-Abs represent a substantial proportion of AQP4-Ab seronegative NMOSD patients despite different underlying mechanisms, clinical manifestations, and treatment response, suggesting MOG-Ab screening in AQP4-Ab seronegative NMOSD patients can facilitate accurate diagnoses and treatments.

Neuromyelitis optica

Neuromyelitis optica (NMO; also known as Devic syndrome) is a clinical syndrome characterized by attacks of acute optic neuritis and transverse myelitis. In most patients, NMO is caused by pathogenetic serum IgG autoantibodies to aquaporin 4 (AQP4), the most abundant water-channel protein in the central nervous system. In a subset of patients negative for AQP4-IgG, pathogenetic serum IgG antibodies to myelin oligodendrocyte glycoprotein, an antigen in the outer myelin sheath of central nervous system neurons, are present. Other causes of NMO (such as paraneoplastic disorders and neurosarcoidosis) are rare. NMO was previously associated with a poor prognosis; however, treatment with steroids and plasma exchange for acute attacks and with immunosuppressants (in particular, B cell-depleting agents) for attack prevention has greatly improved the long-term outcomes. Recently, a number of randomized controlled trials have been completed and the first drugs, all therapeutic monoclonal antibodies, have been approved for the treatment of AQP4-IgG-positive NMO and its formes frustes.

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

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

Is Asian type MS an MS phenotype, an NMO spectrum disorder, or a MOG-IgG related disease?

BACKGROUND

A specific particularity of neurological diseases in Asia is the relative commonality of neuromyelitis optica (NMO) and Asian type MS (OSMS). Both conditions also occur in South American patients. The Brazilian population differs from the European and the Asian populations due to the mixture of ancestralities between European colonizers and African slaves. To better know the clinical characteristics of Brazilian patients with Asian type MS this study aimed to analyze the clinical, radiological and serological data that would help to distinguish between OSMS and NMO and clarify, in a Non-Asian population, if OSMS is an MS phenotype, an NMO spectrum disorder by 2015 classification, or a complement activating antibody to myelin oligodendrocyte glycoprotein (MOG-IgG) antibody-related disease.

METHODS

We selected cases retrospectively with NMO and OSMS in the medical registry of patients with idiopathic inflammatory demyelinating diseases under follow-up since 1997 in Federal Hospital da Lagoa, the principal reference center for MS treatment in Rio de Janeiro, Brazil. OSMS has selective involvement of the optic nerve and spinal cord with no cerebral or cerebellar symptoms associated with small spinal cord lesions and negativity for the aquaporin-4 antibody (AQP4-IgG). NMO full-filled the revised criteria (2006) associated with longitudinally extensive transverse myelitis (LETM). We recorded the following data: ethnicity/skin color, neurologic impairment "at nadir" and "at recovery" of the index events (optic neuritis and transverse myelitis), long term disability, mortality, health quality of life scores by the SF-36 questionnaire, CSF IgG oligoclonal bands and serological AQP4-IgG and MOG-IgG antibodies tested by Cell-based assay. The last brain MRIs were classified as either satisfying or not satisfying MAGNIMS radiologic criteria for MS or typical or not typical for NMOSD. The new classification of NMO spectrum disorders (2015) was applied.

RESULTS

Forty-one OSMS and 122 NMO cases were analyzed. OSMS affected mainly young white women, causing unilateral optic neuritis and partial myelitis with excellent recovery. After a mean disease duration of 20 years, 90% of the patients had free ambulation, and 70% had a mild disability or no disability. Only 7.2% presented a secondary progressive course, and no deaths occurred. All cases had negativity to AQP4-IgG and MOG-IgG biomarkers. 95% had resonance criteria for MS. OSMS differed from NMO by ethnicity, morbidity, and mortality: most were African descendants, with severe motor and visual dysfunction, and one third died. Only NMO cases full-filled the new NMOSD classification (52 AQP4-IgG positive, 29 AQP4-IgG negative, and 41 AQP4-IgG unknown).

CONCLUSION

In Brazilian patients, OSMS and NMO are different immune-mediated diseases. OSMS is a milder MS phenotype.

Predictive value of conventional MRI parameters in first spinal attacks of neuromyelitis optica spectrum disorder

Background:

While spinal cord (SC) attacks of neuromyelitis optica spectrum disorder (NMOSD) are often devastating, signs predictive of their poor clinical outcome have been elusive until now, except for the delay in initiating plasma exchange (PE).

Objective:

We studied the correlation between conventional non-standardized magnetic resonance imaging (MRI) parameters, PE treatment, and clinical data obtained at nadir and recovery.

Methods:

Retrospective study of first SC attacks of NMOSD.

Results:

Sixty-nine Afro-Caribbean NMOSD patients were included (aquaporin-4 (AQP4) antibodies positive in 65%). Median nadir and residual expanded disability status score (EDSS) were, respectively, 7.5 and 4.0. In bivariate analysis, all conventional MRI parameters were correlated with nadir and residual EDSS. In multivariate analysis, nadir EDSS correlated with lesion length ( p = 0.022) and edema ( p = 0.019), whereas residual EDSS correlated with T1w (T1-weighted) hypointense signal ( p = 0.003). Gadolinium enhancement was not associated with outcome.

Conclusion:

A specific pattern of lesions in conventional MRI data is differentially associated with nadir and residual EDSS. Lesions associated with poor prognosis should prompt highly efficient treatment.

Clinical characteristics of myelin oligodendrocyte glycoprotein antibody neuromyelitis optica spectrum disorder

BACKGROUND

Serological antibodies against myelin oligodendrocyte glycoprotein (MOG) are associated with a relapsing autoimmune demyelinating disease of the central nervous system. Initially identified in the context of acute disseminated encephalomyelitis, persistent seropositivity of MOG antibodies is now recognized as a variant of neuromyelitis optica spectrum disorder (NMOSD).

OBJECTIVES

The aim of the study is to describe the epidemiological and clinical features of MOG antibody positive cases and compare our findings with those previously published.

METHODS

This is a retrospective descriptive study of 23 patients with MOG antibody disease who were cared for at Johns Hopkins Hospital over the period from 2015 to 2018. MOG testing was done at Johns Hopkins using the cell based assay (CBA). We describe their epidemiological and clinical features.

RESULTS

Twenty-three patients were included in the study with a female to male ratio of 2.3:1. The mean age of the cohort was 42.6 years, while the mean age at onset was 37 years. The most frequent initial presentation was optic neuritis, followed by ADEM-like encephalopathic clinical picture and transverse myelitis. Five patients showed a monophasic disease course while the rest experienced a relapsing phenotype. Nine patients (39%) experienced immediate relapses on withdrawal of steroids.

CONCLUSIONS

Our cohort showed clinical characteristics comparable with previously published reports of MOG antibody disease worldwide. Unique features of MOG antibody disease are: high frequency of optic neuritis attacks, good long term neurological recovery and sensitivity to steroid use and withdrawal.