Myelin Oligodendrocyte Glycoprotein Antibody Disease Research Articles

FcRn Inhibitor Therapies in Neurologic Diseases.

In the last decade, the landscape of treating autoimmune diseases has evolved with the emergence and approval of novel targeted therapies. Several new biological agents offer selective and target-specific immunotherapy and therefore fewer side effects, such as neonatal Fc receptor (FcRn)-targeting therapy. Neonatal Fc receptor-targeted therapies are engineered to selectively target FcRn through various methods, such as Fc fragments or monoclonal anti-FcRn antibodies. These approaches enhance the breakdown of autoantibodies by blocking the immunoglobulin G recycling pathway. This mechanism reduces overall plasma immunoglobulin levels, including the levels of pathogenic autoantibodies, without affecting the other immunoglobulin class immunoglobulin A, immunoglobulin E, immunoglobulin M, and immunoglobulin D levels. Drugs that inhibit FcRn include efgartigimod, rozanolixizumab, batoclimab, and nipocalimab. These medications can be administered either intravenously or subcutaneously. Numerous clinical trials are currently underway to investigate their effectiveness, safety, and tolerability in various neurological conditions, including myasthenia gravis and other neurological disorders such as chronic inflammatory demyelinating polyneuropathy, myositis, neuromyelitis optica, and myelin oligodendrocyte glycoprotein antibody disease. Positive results from clinical trials of efgartigimod and rozanolixizumab led to their approval for the treatment of generalized myasthenia gravis. Additional clinical trials are still ongoing. Neonatal Fc receptor inhibitor agents seem to be well tolerated. Reported adverse events include headache (most commonly observed with efgartigimod and rozanolixizumab), upper respiratory tract infection, urinary tract infection, diarrhea, pyrexia, and nausea. Additionally, some of these agents may cause transient hypoalbuminemia and hypercholesterolemia notably reported with batoclimab and nipocalimab. In this review, we discuss the available clinical data for FcRN inhibitor agents in treating different neurological autoimmune diseases.

Brain 7T MRI Findings in Patients with Myelin Oligodendrocyte Glycoprotein Antibody Disease (MOGAD) (P9-14.005)

Brain 7T MRI Findings in Patients with Myelin Oligodendrocyte Glycoprotein Antibody Disease (MOGAD) (P9-14.005)

Myelin Oligodendrocyte Glycoprotein Antibody Disease Optic Neuritis: A Structure-Function Paradox?

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is a demyelinating disorder that most commonly presents with optic neuritis (ON) and affects children more often than adults. We report 8 pediatric patients with MOG-associated ON and characterize focal optical coherence tomography (OCT) abnormalities over time that help distinguish this condition from the trajectories of other demyelinating disorders. These OCT findings are examined in the context of longitudinal visual function testing. This is a retrospective case series of 8 pediatric patients with MOG-associated ON who were referred for neuro-ophthalmic evaluation. Longitudinal data for demographics, clinical history, physical examination, and OCT obtained in the course of clinical evaluations were collected through retrospective medical record review. Patients demonstrated acute peripapillary retinal nerve fiber layer (RNFL) thickening in one or both eyes, consistent with optic disc swelling. This was followed by steady patterns of average RNFL thinning, with 9 of 16 eyes reaching significantly low RNFL thickness using OCT platform reference databases ( P < 0.01), accompanied by paradoxical recovery of high-contrast visual acuity (HCVA) in every patient. There was no correlation between HCVA and any OCT measures, although contrast sensitivity (CS) was associated with global thickness, PMB thickness, and nasal/temporal (N/T) ratio, and color vision was associated with PMB thickness. There was a lower global and papillomacular bundle (PMB) thickness ( P < 0.01) in clinically affected eyes compared with unaffected eyes. There was also a significantly higher N:T ratio in clinically affected eyes compared with unaffected eyes in the acute MOG-ON setting ( P = 0.03), but not in the long-term setting. MOG shows a pattern of prominent retinal atrophy, as demonstrated by global RNFL thinning, with remarkable preservation of HCVA but remaining deficits in CS and color vision. These tests may be better clinical markers of vision changes secondary to MOG-ON. Of the OCT parameters measured, PMB thickness demonstrated the most consistent correlation between structural and functional measures. Thus, it may be a more sensitive marker of clinically significant retinal atrophy in MOG-ON. The N:T ratio in acute clinically affected MOG-ON eyes in our study was higher than the N:T ratio of neuromyelitis optica (NMO)-ON eyes and similar to the N:T ratio in multiple sclerosis (MS)-ON eyes as presented in the prior literature. Therefore, MOG may share a more similar pathophysiology to MS compared with NMO.

Clinical and radiological spectrum of acquired inflammatory demyelinating diseases of the central nervous system in a tertiary care center.

Demyelinating diseases of central nervous system (CNS) are a broad spectrum of conditions with autoimmune process against myelin. In a resource limited country like India, it is imperative to perform proper clinical evaluation, neuroimaging to differentiate among various categories of CNS demyelinating diseases to decide regarding further workup and treatment. The objective of our study was to determine clinical presentation, imaging findings, serology results, diagnosis, and treatment outcome of primary demyelinating disorders of CNS. In this prospective study, a total of 44 patients were enrolled over a period of 1 year. After proper evaluation, patients were categorized into different groups applying newer diagnostic criteria. Patients were treated with steroids, appropriate immunomodulatory therapy, and outcomes were analyzed. The majority of cases were of neuromyelitis optica spectrum disorder (NMOSD) (45.5%) with an overall female-to-male ratio of 3.4:1 and mean age of presentation was 30.5 ± 11.15. Myelitis (52.3%) followed by optic neuritis (45.5%) was the most common initial presentation. The most common site of involvement on magnetic resonance imaging was the spinal cord (particularly the cervicodorsal cord). The majority showed good response to therapy (77.27%) and two patients did not survive. Higher disability observed among seropositive NMOSD patients warrants aggressive treatment during the first attack itself. It is important to suspect myelin oligodendrocyte glycoprotein antibody disease in patients with preceding viral infection. A good outcome in the majority is likely due to the availability of serological assays and aggressive immunomodulatory therapy.

A Case of Retinal Vasculitis, Uveitis in Myelin Oligodendrocyte Glycoprotein Antibody Associated Optic Neuritis

Purpose: To report a case of recurrent optic neuritis with uveitis in a patient with myelin oligodendrocyte glycoprotein (MOG)- associated disease.Case summary: A 16-year-old female presented with left eye hyperemia, glare, and headache. The best corrected visual acuity was 1.2 in both eyes with a left relative afferent pupillary defect. Cells in the anterior chamber, optic disc edema, and subretinal fluid were present, and the distal optic nerve was enhanced on orbital magnetic resonance imaging. Although it improved with steroid treatment, it recurred 3 times in 9 months. At the second recurrence, her visual acuity was reduced to light perception, but she responded well to steroids. During the third recurrence, she visited our hospital for the first time and improved with steroid treatment. However, 18 months after treatment, optic neuritis, uveitis, and macular edema occurred, so oral steroids and eye drops were maintained. Serum anti-MOG antibody came out positive, and at the last visit, visual acuity of 1.2 in the left eye and visual function were maintained well.Conclusions: MOG antibody disease (MOGAD) frequently recurs and invades various structures of the eye and various clinical manifestations have been reported. Therefore, if optic neuritis is accompanied by inflammation of the anterior chamber and retinal vessels, the possibility of MOGAD should be considered.

Systemic association of myelin oligodendrocyte glycoprotein antibody disease: A systematic review of literature

AbstractAssociation of MOGAD with various autoimmune and paraneoplastic antibodies has been described in the literature. However, MOGAD with systemic manifestations is rarely encountered and requires a high index of suspicion for evaluation. Searching various databases, we identified 107 studies. After independently assessing the eligibility, finally, 29 studies were selected for review. A total of 1458 MOG patients were included in the study among whom systemic manifestations were present in 253 (17.3%) patients. SLE with ANA positivity was found in a total of 72 (28.4%) patients. Among them, anti‐dsDNA was positive in 10 (3.9%), anti‐smith in 3 (1.2%), anti‐SSA/SSB in 13 (5.1%), anti‐RNP in 3 (1.1%), anti‐Ro 52 in 1 (0.5%), and ENA in 1 (0.5%). APLA was positive in 10 (3.9%), ANCA in 10 (3.9%), RA in 31(12.9%) and thyroid antibody in 35 (13.8%) patients. Simultaneous CNS and PNS involvement was also seen in 21 (8.3%) patients. Systemic involvement is not an uncommon phenomenon in MOGAD and in future may add to the spectrum of the disease.

NCMP-21. AQP4-MOG DOUBLE-POSITIVE PARANEOPLASTIC NEUROLOGICAL SYNDROME IN A PATIENT WITH TRIPLE NEGATIVE BREAST CANCER

Abstract We report a rare case of paraneoplastic neurological syndrome (PNS) with dual seropositivity of anti-aquaporin-4 (AQP-4) and myelin oligodendrocyte glycoprotein (MOG) antibodies in a 40 year-old lady with metastatic triple negative breast cancer with involvement of mediastinal, right axillary, and supraclavicular lymph nodes. She received multiple lines of anti-neoplastic treatment including immunotherapy with pembrolizumab as well as chemotherapy with taxol, carboplatin, gemcitabine, capecitabine, cytoxan, sacituzumab and nevalbine. Paraneoplastic meningoencephalomyelitis developed 2 years after diagnosis of breast cancer and 1 year after discontinuation of immunotherapy with pembrolizumab. She first developed longitudinally extending transverse myelitis extending from T11-12 that symptomatically improved with high dose intravenous methylprednisolone. One month later she developed left optic neuritis and meningoencephalitis with new enhancing lesions in the brain and spinal leptomeninges. Cerebrospinal fluid (CSF) analysis during both episodes revealed normal glucose, protein, elevated white blood cell count. Cytology was negative for malignancy. CSF was positive for neuromyelitis optica (NMO) IgG antibody APQ-4 and autoimmune myelopathy panel was positive for MOG antibody. Patient had significant clinical and radiographic improvement after completion of plasmapheresis and intravenous immunoglobulin. There was resolution of pleocytosis on repeat CSF testing. She did not have recurrence of paraneoplastic syndrome with maintenance rituximab every six months and daily low dose prednisone. She succumbed to progressive systemic metastatic disease 4.5 years after her breast cancer diagnosis. This case demonstrates that these antibodies can occur concurrently and cause clinical features like both neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD) in a patient with a singular type of cancer. We highlight the importance of testing for paraneoplastic etiology in cancer patients with radiographic menigoencephalomyelitis or meningitis with atypical symptoms of meningeal carcinomatosis and/or CSF profile negative for leptomeningeal carcinomatosis.

28 Neurocognitive profile of pediatric acquired demyelinating syndrome with and without myelin oligodendrocyte glycoprotein antibody disease (MOGAD)

Objective:Pediatric acquired demyelinating syndromes (PADS) include a heterogeneous group of diagnoses, including acute disseminated encephalomyelitis (ADEM), neuromyelitis optica spectrum disorders (NMOSD), optic neuritis (ON) and transverse myelitis (TM). Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is often associated with demyelinating conditions, but may also present with encephalopathy without demyelinating lesions. Approximately 30% of patients diagnosed with MOGAD experience a relapse. Neurocognitive outcomes in PADS have reduced performance on tasks related to attention, processing speed, visual motor, and fine motor functioning. Psychosocial problems include anxiety, depression, and fatigue. Neurocognitive and psychosocial impacts of MOGAD events for the pediatric population are sparse. The current study sought to characterize neurocognitive sequelae from MOGAD (MAGAD+) compared to patients diagnosed with PADS without MOGAD (MOGAD-).Participants and Methods:Twenty children and adolescents (6–18 years) diagnosed with PADS were recruited using a clinic convenience sample of patients. Study participants completed a neurocognitive battery and parents completed questionnaires of behavioral and emotional functioning. Demographic and medical variables were collected via retrospective chart review. Chi square and t-test analyses were used to compare MOGAD+ and MOGAD- groups. Performance on neuropsychological and behavioral questionnaires were compared to established sex and age norms to assess the degree to which group means deviate from normative expectations.Results:MOGAD+ and MOGAD- groups did not significantly differ based on demographic, neurocognitive, or parent reported social and behavioral functioning. Neurocognitive testing documented mean scores that were in the average range between groups. Notable variability in performance was observed within both MOGAD+ and MOGAD- groups. Bilateral fine motor deficits, visual motor, visual perception attention, and executive functioning deficits were notable for the combined PADS group, with 30-50% performing &gt;1.5 SD below the mean. The number of white matter lesions or hospital duration were not significantly associated with performance on neurocognitive measures. However, older age of onset of PADS was significantly correlated with lower performance on visual motor integration and visual perception tasks (r(18) = -.50 p = .026; r(18) = -.53 p = .016). Findings also revealed associations of shorter hospitalization stays with higher behavioral symptoms on a parent measure of social/behavioral functioning (r(18) = -.47 p = .037).Conclusions:Consistent with the PADS literature, relative to control norms, lower performance on tasks related to attention, executive functioning, visual motor, and fine motor skills, irrespective of MOGAD status, are observed in the current study. The variability of functioning and heterogeneity observed across PADS diagnoses warrants further study to better understand the impact of clinical course, treatment outcomes, and neuropsychological sequelae over time in this population. Higher behavioral distress with shorter hospital stays may indicate a potential opportunity for patient and family education preparing for return to home/community. The current study was limited by small sample size, variable time since hospitalization, and heterogeneous diagnoses within PADS that make it difficult to generalize findings. Future studies could prospectively follow patients over time to better understand the trajectory of recovery, identify predictors for relapse, and those at greatest risk of neurocognitive and behavioral deficits.

Anti-aquaporin-4 immunoglobulin G/anti-myelin oligodendrocyte glycoprotein immunoglobulin G double-positive paraneoplastic neurological syndrome in a patient with triple-negative breast cancer.

We report a rare case of paraneoplastic neurological syndrome with dual seropositivity of anti-aquaporin-4 and myelin oligodendrocyte glycoprotein antibodies in a 40 year-old woman with metastatic triple-negative breast cancer. She received multiple lines of anti-neoplastic treatment, including immunotherapy with pembrolizumab, as well as cytotoxic chemotherapy. Paraneoplastic meningoencephalomyelitis developed 2 years after diagnosis of breast cancer and 1 year after discontinuation of immunotherapy with pembrolizumab. She first developed longitudinally extending transverse myelitis followed by left optic neuritis and meningoencephalitis with new enhancing lesions in the brain and spinal leptomeninges. Cerebrospinal fluid analysis during both episodes showed normal glucose and protein, and elevated white blood cell count. Cytology was negative for malignancy. Cerebrospinal fluid was positive for neuromyelitis optica immunoglobulin G antibody anti-aquaporin-4, and autoimmune myelopathy panel was positive for myelin oligodendrocyte glycoprotein antibody. The patient had significant clinical and radiographic improvement after completion of five cycles of plasmapheresis followed by intravenous immunoglobulin. She did not have recurrence of paraneoplastic syndrome with maintenance rituximab every 6 months and daily low-dose prednisone. She succumbed to progressive systemic metastatic disease 4.5 years after her breast cancer diagnosis. This case shows that these antibodies can occur concurrently and cause clinical features, such as both neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody disease, in a patient with a singular type of cancer. We highlight the importance of testing for paraneoplastic etiology in cancer patients with radiographic menigoencephalomyelitis or meningitis with atypical symptoms of meningeal carcinomatosis and/or cerebrospinal fluid profile negative for leptomeningeal carcinomatosis.

Intravenous immunoglobulin treatment for acute attacks in myelin oligodendrocyte glycoprotein antibody disease

Background: The potential therapeutic benefit of intravenous immunoglobulins (IVIGs) for acute attacks of myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is unknown. Objective: The objective was to describe the outcomes of IVIG treatment for acute MOGAD attacks. Methods: A retrospective observational study involving seven tertiary neuroimmunology centers. Data collection included patients’ demographics, Expanded Disability Status Scale (EDSS), and visual acuity (VA) before the attack, at the nadir of the attack before IVIG treatment, and at follow-up visits ⩾3 months after treatment. Results: Thirty-nine patients were included, of which 21 (53.8%) were female. The median age was 23 years (range 5–74 years), and the median disease duration was 4 months (range 0–93 months). The most common type of attack treated with IVIG was isolated optic neuritis (ON) (unilateral n = 14, bilateral n = 5, associated with transverse myelitis (TM), n = 1), followed by acute disseminated encephalomyelitis (ADEM) (n = 8), multifocal (n = 7), TM (n = 3), brainstem (n = 1), and other encephalitis (n = 1). A significant improvement in both the EDSS and VA measures was observed at follow-up compared to the time of IVIG treatment initiation (p < 0.0001 for both outcome measures). Conclusion: IVIG may be an effective treatment option for acute MOGAD attacks. Further prospective studies are warranted to validate our results.

MRI features of myelin oligodendrocyte glycoprotein antibody disease: a descriptive study—how it differs from neuromyelitis optica spectrum disorders and multiple sclerosis

BackgroundMyelin oligodendrocyte glycoprotein antibody disease (MOGAD) is a novel inflammatory demyelinating disease of the central nervous system. This study aims to characterize the MRI features of MOGAD and contrast our results with the findings previously described in the literature and its close differential diagnoses.ResultsMost of the abnormal findings are in the brainstem followed by supratentorial deep/subcortical white matter and optic nerves. Brain lesions in MOGAD tend to show a pattern that is different from multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD). Orbital MRIs show features of bilateral longitudinally extensive optic neuritis predominantly involving the anterior segments. The spinal cord is the least affected and mostly shows longitudinally extensive lesions in the dorsal spine.ConclusionsWe could identify numerous characteristic radiological features that could help distinguish MOGAD from NMOSD and MS. We hope this study helps clinicians systematically evaluate and manage patients with clinical features of neuroinflammatory diseases.

Leptomeningeal enhancement of myelin oligodendrocyte glycoprotein antibody-associated encephalitis: uncovering novel markers on contrast-enhanced fluid-attenuated inversion recovery images.

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is a newly defined autoimmune inflammatory demyelinating central nervous system (CNS) disease characterized by antibodies against MOG. Leptomeningeal enhancement (LME) on contrast-enhanced fluid-attenuated inversion recovery (CE-FLAIR) images has been reported in patients with other diseases and interpreted as a biomarker of inflammation. This study retrospectively analyzed the prevalence and distribution of LME on CE-FLAIR images in children with MOG antibody-associated encephalitis (MOG-E). The corresponding magnetic resonance imaging (MRI) features and clinical manifestations are also presented. The brain MRI images (native and CE-FLAIR) and clinical manifestations of 78 children with MOG-E between January 2018 and December 2021 were analyzed. Secondary analyses evaluated the relationship between LME, clinical manifestations, and other MRI measures. Forty-four children were included, and the median age at the first onset was 70.5 months. The prodromal symptoms were fever, headache, emesis, and blurred vision, which could be progressively accompanied by convulsions, decreased level of consciousness, and dyskinesia. MOG-E showed multiple and asymmetric lesions in the brain by MRI, with varying sizes and blurred edges. These lesions were hyperintense on the T2-weighted and FLAIR images and slightly hypointense or hypointense on the T1-weighted images. The most common sites involved were juxtacortical white matter (81.8%) and cortical gray matter (59.1%). Periventricular/juxtaventricular white matter lesions (18.2%) were relatively rare. On CE-FLAIR images, 24 (54.5%) children showed LME located on the cerebral surface. LME was an early feature of MOG-E (P = 0.002), and cases without LME were more likely to involve the brainstem (P = 0.041). LME on CE-FLAIR images may be a novel early marker among patients with MOG-E. The inclusion of CE-FLAIR images in MRI protocols for children with suspected MOG-E at an early stage may be useful for the diagnosis of this disease.

MRI to differentiate multiple sclerosis, neuromyelitis optica, and myelin oligodendrocyte glycoprotein antibody disease.

Differentiating multiple sclerosis (MS) from other relapsing inflammatory autoimmune diseases of the central nervous system such as neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is crucial in clinical practice. The differential diagnosis may be challenging but making the correct ultimate diagnosis is critical, since prognosis and treatments differ, and inappropriate therapy may promote disability. In the last two decades, significant advances have been made in MS, NMOSD, and MOGAD including new diagnostic criteria with better characterization of typical clinical symptoms and suggestive imaging (magnetic resonance imaging [MRI]) lesions. MRI is invaluable in making the ultimate diagnosis. An increasing amount of new evidence with respect to the specificity of observed lesions as well as the associated dynamic changes in the acute and follow-up phase in each condition has been reported in distinct studies recently published. Additionally, differences in brain (including the optic nerve) and spinal cord lesion patterns between MS, aquaporin4-antibody-positive NMOSD, and MOGAD have been described. We therefore present a narrative review on the most relevant findings in brain, spinal cord, and optic nerve lesions on conventional MRI for distinguishing adult patients with MS from NMOSD and MOGAD in clinical practice. In this context, cortical and central vein sign lesions, brain and spinal cord lesions characteristic of MS, NMOSD, and MOGAD, optic nerve involvement, role of MRI at follow-up, and new proposed diagnostic criteria to differentiate MS from NMOSD and MOGAD were discussed.

The Role of Microorganisms in the Etiopathogenesis of Demyelinating Diseases.

Multiple sclerosis (MS), neuromyelitis optica (NMO) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD) are inflammatory diseases of the central nervous system (CNS) with a multifactorial aetiology. Environmental factors are important for their development and microorganisms could play a determining role. They can directly damage the CNS, but their interaction with the immune system is even more important. The possible mechanisms involved include molecular mimicry, epitope spreading, bystander activation and the dual cell receptor theory. The role of Epstein-Barr virus (EBV) in MS has been definitely established, since being seropositive is a necessary condition for the onset of MS. EBV interacts with genetic and environmental factors, such as low levels of vitamin D and human endogenous retrovirus (HERV), another microorganism implicated in the disease. Many cases of onset or exacerbation of neuromyelitis optica spectrum disorder (NMOSD) have been described after infection with Mycobacterium tuberculosis, EBV and human immunodeficiency virus; however, no definite association with a virus has been found. A possible role has been suggested for Helicobacter pylori, in particular in individuals with aquaporin 4 antibodies. The onset of MOGAD could occur after an infection, mainly in the monophasic course of the disease. A role for the HERV in MOGAD has been hypothesized. In this review, we examined the current understanding of the involvement of infectious factors in MS, NMO and MOGAD. Our objective was to elucidate the roles of each microorganism in initiating the diseases and influencing their clinical progression. We aimed to discuss both the infectious factors that have a well-established role and those that have yielded conflicting results across various studies.

Inappropriate Duration of Corticosteroids in Optic Neuritis in Suspected Myelin Oligodendrocyte Glycoprotein Antibody Disease Can Lead to Early Relapse.

Taha, Farris A. MD; Few, William Evans BS; Berman, Eric L. MDEditor(s): Avery, Robert DO; Golnik, Karl C. MD; Froment, Caroline MD, PhD; Wang, An-Guor MD Author Information

COVID-19 and the Pandemic-Related Aspects in Pediatric Demyelinating Disorders

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as Coronavirus-19 (COVID-19) infection, has been associated with several neurological symptoms, including acute demyelinating syndromes (ADS). There is a growing body of literature discussing COVID-19 and demyelinating conditions in adults; however, there is less published about COVID-19 demyelinating conditions in the pediatric population. This review aims to discuss the impact of COVID-19 in pediatric patients with central nervous system ADS (cADS) and chronic demyelinating conditions. We reviewed PubMed, Google Scholar, and Medline for articles published between December 1, 2019 and October 25, 2022 related to COVID-19 and pediatric demyelinating conditions. Of 56 articles reviewed, 20 cases of initial presentation of ADS associated with COVID-19 were described. The most commonly described cADS associated with COVID-19 infection in children was Acute Disseminated Encephalomyelitis followed by Transverse Myelitis. Cases of Myelin Oligodendrocyte Glycoprotein Antibody Disease, Neuromyelitis Optica Spectrum Disorder, and Multiple Sclerosis are also described. The risk of severe COVID-19 in pediatric patients with demyelinating conditions appears low, including in patients on disease modifying therapies, but studies are limited. The pandemic did affect disease modifying therapies in ADS, whether related to changes in prescriber practice or access to medications. COVID-19 is associated with ADS in children and the COVID-19 pandemic has impacted pediatric patients with demyelinating conditions in various ways.

What neuropathology teaches us about autoimmune encephalitides, autoimmune epilepsies, and encephalomyelitides.

Delineation of the autoimmune encephalitides with antibodies against neural surface antigens (anti-N-Methyl-D-aspartate, anti-leucine-rich glioma-inactivated protein 1, and others), autoimmune-associated epilepsies (Rasmussen encephalitis, paraneoplastic encephalitides, temporal lobe epilepsy with antibodies against glutamic acid decarboxylase), and encephalomyelitides with glial antibodies (neuromyelitis optica spectrum disorder, myelin oligodendrocyte glycoprotein antibody disease) has been a major advance in neurology. But how do these inflammatory diseases "work"? What kind of interaction between elements of the immune system and brain cells leads to these conditions? The only direct way of answering these questions is to investigate affected brain tissue by neuropathological techniques. They provide morphological and, in part, temporal information on the elements and localization of the disease process. Molecular techniques broaden and support these data. Brain tissue becomes available through autopsies and brain biopsies, obtained for diagnostic or therapeutic interventions. The limitations of neuropathological pathogenic research are discussed. Finally, representative neuropathological findings in autoimmune encephalitides and related conditions are summarized.

The absence of antibodies in longitudinally extensive transverse myelitis and the impact on prognosis (P9-5.029)

<h3>Objective:</h3> Evaluation of clinical outcomes in LETM. <h3>Background:</h3> Longitudinally extensive transverse myelitis (LETM) is typically defined as spinal cord inflammation that spans 3 or more vertebral segments on MRI. It is a prototypical manifestation of neuromyelitis optica spectrum disorder (NMOSD) but is also seen in myelin oligodendrocyte glycoprotein antibody disease (MOGAD) and much less commonly multiple sclerosis. In some cases, despite extensive investigation, a definitive diagnosis cannot be reached, a condition referred to as double seronegative LETM (dsLETM). <h3>Design/Methods:</h3> Cohort study of LETM cases reviewed in NMO UK Highly Specialised Service at the Walton Centre NHS Foundation Trust between Jan 2008-March 2022. Clinical presentation, radiological characteristics, aquaporin-4 antibodies (AQP4-IgG) and MOG antibodies, relapses, treatment, and EDSS at follow-up were extracted from case records. <h3>Results:</h3> LETM=93 cases were identified; NMOSD=41 (AQP4-IgG positive; 88%), dsLETM=29, MOGAD=17, others=6. The median onset age was 46 (15–85) yrs with a median follow-up of 46 (1–144) months. EDSS at nadir was similar between subgroups (NMOSD; 7, MOGAD; 7.5, dsLETM; 6.7, p&gt;0.05) but patients with dsLETM were less likely to relapse (dsLETM; 21% vs. NMOSD; 56% vs. MOGAD; 29%, p=0.008). Long term immunosuppression was used in NMOSD (100%), MOGAD (76%) and dsLETM (34%) and was associated with a reduction in median annualised relapse rate (NMOSD; 1.65 to 0.09, MOGAD; 0.75 to 0.07, and dsLETM; 1 to 0.11). Although EDSS scores at last review were higher in NMOSD than MOGAD (6 vs. 4; p=0.018) and dsLETM (6 vs 4.5; p=0.04), dsLETM patients still reached a significant disability (EDSS&gt;6) in 35% of cases. <h3>Conclusions:</h3> Patients with dsLETM relapsed less as compared to NMOSD and MOGAD and immunosuppression reduced the risk further. Although last EDSS was lower in dsLETM as compared to NMOSD, a third of patients still suffered from significant disability. <b>Disclosure:</b> Dr. Rocchi has nothing to disclose. Dr. Forcadela has nothing to disclose. Dr. Jacob has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for ALEXION. Dr. Hamid has nothing to disclose. Dr. Huda has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Guidepoint.

Most Opticospinal Demyelination is NMOSD, not MS-A 17-year UK Longitudinal Cohort Study (P5-3.003)

<h3>Objective:</h3> To evaluate clinical outcomes in a cohort of patients with Opticospinal Demyelination (OSD). <h3>Background:</h3> Classification of central nervous system inflammation has progressed with the identification of aquaporin-4 (AQP4) antibodies in neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein (MOG) antibodies in MOG antibody disease (MOGAD) in addition to multiple sclerosis (MS). However, as defined in 2003, patients with opticospinal demyelination (optic neuritis (ON), short-segment transverse myelitis (TM), and brain imaging not supportive of MS) do not fulfil internationally approved criteria for MS, NMOSD, or MOGAD. <h3>Design/Methods:</h3> Between 2003–2005, 128 cases of OSD were reported via the British Neurological Surveillance Unit. In 2011, 2015 and 2022 patients and physicians were contacted for clinical, radiological, and serological (e.g., AQP4-IgG and MOG-IgG) data as part of a prospective longitudinal cohort study. <h3>Results:</h3> Of 128 cases, 67 (52%) patients fulfilled OSD diagnostic criteria. At 17 years 39/60 patients (65%) now met NMOSD diagnostic criteria, 14 (23%) had MS and 7 (12%) had OSD. The median time to diagnosis of NMOSD was 107 months (85–261) and to MS was 189 months (79–346). The median age of OSD patients at onset was 37 (25–48) years and 5/7 were male. A relapsing course was observed in 6/7 patients with a median annualised relapse rate of 0.22 (0.13–0.49). At last follow-up the median EDSS was 2.5 (range; 1–6.5) and only 2/7 patients had an EDSS&gt;3.5. <h3>Conclusions:</h3> OSD is diagnostically distinct from MS, NMOSD, and MOGAD. However, after 2 decades most OSD patients reached a diagnosis of NMOSD or MS, so OSD may lie on a spectrum with these conditions. Of the 12% of cases that retained OSD classification, all but 1 had a relapsing course but rates of significant disability were low. Future studies should focus on characterising diagnostic and prognostic biomarkers in this unique subtype of non-MS CNS inflammation. <b>Disclosure:</b> Dr. Forcadela has nothing to disclose. Dr. Rocchi has nothing to disclose. Dr. Panicker has nothing to disclose. Kerry Mutch has nothing to disclose. Dr. Huda has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Guidepoint. Dr. Jacob has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for ALEXION. Dr. Hamid has nothing to disclose.

Predictors of Conversion from Positive to Negative Myelin Oligodendrocyte Glycoprotein (MOG) Antibody Status (P9-3.011)

<h3>Objective:</h3> The goal of this study is to characterize the clinical course of patients with Myelin Oligodendrocyte Glycoprotein Antibody Disease (MOGAD) who seroconvert from a positive to negative MOG antibody status, and to determine predictors of seroconversion. <h3>Background:</h3> MOGAD is a neuroinflammatory disorder characterized by demyelination of the optic nerve, brain, or spinal cord, and can be either relapsing or monophasic. Persistent MOG antibody positivity has been identified as a potential predictor of disease-related relapses, however there has been limited research regarding what determines whether patients remain seropositive or convert to a negative MOG antibody status. <h3>Design/Methods:</h3> The Massachusetts General Hospital Neuroimmunology Clinic maintains a list of patients with MOGAD based on queries of the Massachusetts General Brigham Research Patient Data Registry database and updated with clinic visits. Patients evaluated through July 2022 were included in a chart review focused on MOG serostatus, titer levels, and potential predictors of MOG serostatus. Data analysis was conducted in Stata/SE 17.0. <h3>Results:</h3> We identified 66 patients who had at least 2 MOG antibody tests 6 months apart (60.6% females and 39.4% males). Of these, 47 had persistently positive MOG titers, and 18 had positive titers that became negative. 5 individuals had negative titers that later converted to positive. Of the 18 patients that developed negative titers, only 1 had a subsequent documented relapse, which was associated with discontinued immunotherapy and titers which became positive again at the time of relapse. Predictors of conversion to negative IgG on multivariate logistic regression included low initial MOG titers (defined as titers &lt;1:100), male sex, and childhood onset of disease. <h3>Conclusions:</h3> Low initial MOG titers, male sex, and childhood onset of disease can help predict future conversion to negative MOG serostatus. Further analysis of this cohort will focus on the effect of various immunotherapies and their timing on MOG antibody status. <b>Disclosure:</b> Ms. Hayman has nothing to disclose. The institution of Dr. Vishnevetsky has received research support from National MS Society. The institution of Dr. Vishnevetsky has received research support from NIH (NeuroNext). Ms. Romanow has received research support from Freeman Pain Award @ Harvard Medical School. Dr. Levy has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Mitsubishi Pharma. Dr. Levy has received personal compensation in the range of $500-$4,999 for serving as a Consultant for UCB Pharma. Dr. Levy has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Sanofi. Dr. Levy has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Alexion. Dr. Levy has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Horizon. Dr. Levy has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Genentech. Dr. Levy has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Elsevier. Dr. Levy has received personal compensation in the range of $10,000-$49,999 for serving as an Expert Witness for Various law firms. The institution of Dr. Levy has received research support from National Institutes Health.