Details and outcomes of a large cohort of MOG-IgG associated optic neuritis

Diagnostic Value of Inter-Eye Difference Metrics on OCT for Myelin Oligodendrocyte Glycoprotein Antibody-Associated Optic Neuritis

BACKGROUND AND OBJECTIVES

The 2022 International Consortium for Optic Neuritis diagnostic criteria for optic neuritis (ON) include optical coherence tomography (OCT). The diagnostic value of intereye difference (IED) metrics is high for ON in patients with multiple sclerosis and aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorders, but unknown in myelin oligodendrocyte glycoprotein antibody-associated ON (MOG-ON).

METHODS

A multicenter validation study was conducted on the published IED cutoff values (>4% or >4 μm in the macular ganglion cell and inner plexiform layer [mGCIP] or >5% or >5 μm in the peripapillary retinal nerve fiber layer [pRNFL]) in individuals with MOG-ON and age-matched and sex-matched healthy controls (HCs). Structural data were acquired with Spectralis spectral-domain OCT >6 months after ON. We calculated sensitivity, specificity, and receiver operating characteristics for both intereye percentage (IEPD) and absolute difference (IEAD).

RESULTS

A total of 66 individuals were included (MOG-ON N = 33; HCs N = 33). ON was unilateral in 20 and bilateral in 13 subjects. In the pooled analysis, the mGCIP IEPD was most sensitive (92%), followed by the mGCIP IEAD (88%) and pRNFL (84%). The same pattern was found for the specificity (mGCIP IEPD 82%, IEAD 82%; pRNFL IEPD 82%, IEAD 79%).In subgroup analyses, the diagnostic sensitivity was higher in subjects with unilateral ON (>99% for all metrics) compared with bilateral ON (61%-78%).

DISCUSSION

In individuals with MOG-ON, the diagnostic accuracy of OCT-based IED metrics for ON was high, especially of mGCIP IEPD.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that the intereye difference on OCT can distinguish between those with MOG and normal controls.

NMOSD and MOGAD: an evolving disease spectrum

Neuromyelitis optica (NMO) spectrum disorder (NMOSD) is a relapsing inflammatory disease of the CNS, characterized by the presence of serum aquaporin 4 (AQP4) autoantibodies (AQP4-IgGs) and core clinical manifestations such as optic neuritis, myelitis, and brain or brainstem syndromes. Some people exhibit clinical characteristics of NMOSD but test negative for AQP4-IgG, and a subset of these individuals are now recognized to have serum autoantibodies against myelin oligodendrocyte glycoprotein (MOG) - a condition termed MOG antibody-associated disease (MOGAD). Therefore, the concept of NMOSD is changing, with a disease spectrum emerging that includes AQP4-IgG-seropositive NMOSD, MOGAD and double-seronegative NMOSD. MOGAD shares features with NMOSD, including optic neuritis and myelitis, but has distinct pathophysiology, clinical profiles, neuroimaging findings (including acute disseminated encephalomyelitis and/or cortical encephalitis) and biomarkers. AQP4-IgG-seronegative NMOSD seems to be a heterogeneous condition and requires further study. MOGAD can manifest as either a monophasic or a relapsing disease, whereas NMOSD is usually relapsing. This Review summarizes the history and current concepts of NMOSD and MOGAD, comparing epidemiology, clinical features, neuroimaging, pathology and immunology. In addition, we discuss new monoclonal antibody therapies for AQP4-IgG-seropositive NMOSD that target complement, B cells or IL-6 receptors, which might be applied to MOGAD in the near future.

Radiologic Predictors of Visual Outcome in Myelin Oligodendrocyte Glycoprotein-Related Optic Neuritis

PURPOSE

This study aimed to determine whether magnetic resonance imaging (MRI) biomarkers are associated with visual prognosis in myelin oligodendrocyte protein (MOG)-associated optic neuritis (ON).

DESIGN

Cross-sectional analysis.

PARTICIPANTS

Patients meeting 2023 international diagnostic criteria for MOG antibody-associated disease who were seen for first episodes of MOG-associated ON at 3 tertiary neuro-ophthalmology practices between January 2017 and July 2023 were enrolled. Patients who received < 3 months of neuro-ophthalmic follow-up and did not demonstrate visual recovery (visual acuity [VA] ≥ 20/20 and visual field mean deviation [VFMD] > -5.0 dB) during this time were excluded.

METHODS

Patients underwent contrast-enhanced, fat-suppressed MRI of the brain and orbits within 1 month of symptom onset.

MAIN OUTCOME MEASURES

The associations between radiologic biomarkers and poor VA outcome (< 20/40), incomplete VA recovery (< 20/20), and poor VFMD outcome (VFMD < -5.0 dB) were assessed using multivariable logistic regression adjusting for time from symptom onset to treatment and nadir VA or VFMD. Radiologic biomarkers included length of optic nerve enhancement (> 25% vs. < 25%; > 50% vs. < 50%; and > 75% vs. < 75%); degree of orbital, canalicular, and intracranial or chiasmal optic nerve enhancement (mild vs. moderate to severe compared with the lacrimal gland); and absence versus presence of optic nerve sheath enhancement on baseline T1-weighted MRI.

RESULTS

A total of 129 eyes of 92 patients (median age, 37.0 years [interquartile range, 20.8-51.3 years]; 65.2% female) were included. Poor VA outcome was seen in 6.2% of patients, incomplete VA recovery was seen in 19.4% of patients, and poor VFMD outcome was seen in 16.9% of patients. Compared with eyes with moderate to severe enhancement, eyes with mild orbital optic nerve enhancement were more likely to have poor VA outcome (odds ratio [OR], 8.57; 95% confidence interval [CI], 1.85-51.14; P = 0.009), incomplete VA recovery (OR, 7.31, 95% CI, 2.42-25.47; P = 0.001), and poor VFMD outcome (adjusting for time to treatment: OR, 6.81; 95% CI, 1.85-28.98; P = 0.005; adjusting for nadir VFMD: OR, 11.65; 95% CI, 1.60-240.09; P = 0.04). Lack of optic nerve sheath enhancement additionally was associated with incomplete VA recovery (OR, 3.86; 95% CI, 1.19-12.85; P = 0.02) compared with the presence of enhancement. These associations remained consistent in subgroup logistic regression analysis of MRIs performed before initiation of treatment but were not seen in pairwise analysis of MRIs performed after treatment.

CONCLUSIONS

In eyes with first MOG-associated ON episodes, milder enhancement in the orbital optic nerve was associated with poorer VA and visual field recovery. Prospective and mechanistic studies are needed to confirm the prognostic usefulness of MRI in MOG-associated ON.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

MOG antibody-associated optic neuritis

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is a demyelinating disorder, distinct from multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). MOGAD most frequently presents with optic neuritis (MOG-ON), often with characteristic clinical and radiological features. Bilateral involvement, disc swelling clinically and radiologically, and longitudinally extensive optic nerve hyperintensity with associated optic perineuritis on MRI are key characteristics that can help distinguish MOG-ON from optic neuritis due to other aetiologies. The detection of serum MOG immunoglobulin G utilising a live cell-based assay in a patient with a compatible clinical phenotype is highly specific for the diagnosis of MOGAD. This review will highlight the key clinical and radiological features which expedite diagnosis, as well as ancillary investigations such as visual fields, visual evoked potentials and cerebrospinal fluid analysis, which may be less discriminatory. Optical coherence tomography can identify optic nerve swelling acutely, and atrophy chronically, and may transpire to have utility as a diagnostic and prognostic biomarker. MOG-ON appears to be largely responsive to corticosteroids, which are often the mainstay of acute management. However, relapses are common in patients in whom follow-up is prolonged, often in the context of early or rapid corticosteroid tapering. Establishing optimal acute therapy, the role of maintenance steroid-sparing immunotherapy for long-term relapse prevention, and identifying predictors of relapsing disease remain key research priorities in MOG-ON.

MOG Antibody Disease: Nuances in Presentation, Diagnosis, and Management

PURPOSE OF REVIEW

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is a distinct neuroinflammatory condition characterized by attacks of optic neuritis, transverse myelitis, and other demyelinating events. Though it can mimic multiple sclerosis and neuromyelitis optica spectrum disorder, distinct clinical and radiologic features which can discriminate these conditions are now recognized. This review highlights recent advances in our understanding of clinical manifestations, diagnosis, and treatment of MOGAD.

RECENT FINDINGS

Studies have identified subtleties of common clinical attacks and identified more rare phenotypes, including cerebral cortical encephalitis, which have broadened our understanding of the clinicoradiologic spectrum of MOGAD and culminated in the recent publication of proposed diagnostic criteria with a familiar construction to those diagnosing other neuroinflammatory conditions. These criteria, in combination with advances in antibody testing, should simultaneously lead to wider recognition and reduced incidence of misdiagnosis. In addition, recent observational studies have raised new questions about when to treat MOGAD chronically, and with which agent. MOGAD pathophysiology informs some of the relatively unique clinical and radiologic features which have come to define this condition, and similarly has implications for diagnosis and management. Further prospective studies and the first clinical trials of therapeutic options will answer several remaining questions about the peculiarities of this condition.

Prognostic factors of first-onset optic neuritis based on diagnostic criteria and antibody status: a multicentre analysis of 427 eyes

BACKGROUND

Optic neuritis (ON) prognosis is influenced by various factors including attack severity, underlying aetiologies, treatments and consequences of previous episodes. This study, conducted on a large cohort of first ON episodes, aimed to identify unique prognostic factors for each ON subtype, while excluding any potential influence from pre-existing sequelae.

METHODS

Patients experiencing their first ON episodes, with complete aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) antibody testing, and clinical data for applying multiple sclerosis (MS) diagnostic criteria, were enrolled. 427 eyes from 355 patients from 10 hospitals were categorised into four subgroups: neuromyelitis optica with AQP4 IgG (NMOSD-ON), MOG antibody-associated disease (MOGAD-ON), ON in MS (MS-ON) or idiopathic ON (ION). Prognostic factors linked to complete recovery (regaining 20/20 visual acuity (VA)) or moderate recovery (regaining 20/40 VA) were assessed through multivariable Cox regression analysis.

RESULTS

VA at nadir emerged as a robust prognostic factor for both complete and moderate recovery, spanning all ON subtypes. Early intravenous methylprednisolone (IVMP) was associated with enhanced complete recovery in NMOSD-ON and MOGAD-ON, but not in MS-ON or ION. Interestingly, in NMOSD-ON, even a slight IVMP delay in IVMP by >3 days had a significant negative impact, whereas a moderate delay up to 7-9 days was permissible in MOGAD-ON. Female sex predicted poor recovery in MOGAD-ON, while older age hindered moderate recovery in NMOSD-ON and ION.

CONCLUSION

This comprehensive multicentre analysis on first-onset ON unveils subtype-specific prognostic factors. These insights will assist tailored treatment strategies and patient counselling for ON.

Timing of immunotherapeutic strategies for first-episode Isolated Anti-Myelin Oligodendrocyte Glycoprotein-IgG Associated Optic Neuritis: A single-centre retrospective study

Background

There is no consensus on the timing of immunotherapeutic strategies for the first-episode anti-myelin oligodendrocyte glycoprotein-IgG (MOG-IgG) associated disorders (MOGAD) presenting with isolated optic neuritis (ON).

Objective

To investigate the optimal timing of intravenous methylprednisolone therapy (IVMP) and necessity of immunosuppressive therapy for the first-episode isolated MOG-IgG associated ON (iMOG-ON).

Methods

Adult patients with the first-episode iMOG-ON were enrolled. Primary outcomes were best-corrected visual acuity (BCVA) at last follow-up (i.e. final BCVA) and relapse, and their predictors were assessed by multivariate analysis.

Results

62 patients were included. Logistic regression analysis revealed BCVA at the time of IVMP (odds ratio: 0.463 (95 % confidence interval (CI) 0.310-0.714) was a factor predictive of regaining a final BCVA of 0.0 logMAR vision, and its Youden optimal criterion was <0.175 logMAR by plotting the receiver operating characteristic curve. The time-dependent cox proportional hazards model exhibited MMF therapy was not associated with a high likelihood of relapse-free survival (HR = 1.099, 95 % CI 0.892-1.354, P = 0.376) after adjusting for age of onset, gender, and baseline MOG serum titers. Similar analysis exhibited evidently negative association between high MOG-IgG serum titers at baseline and relapse-free survival after adjusting for age of onset, gender, and MMF therapy (HR = 0.339, 95 % CI 0.155-0.741, P = 0.007).

Conclusions

During the first episode of iMOG-ON, the optimal timing of IVMP may be a short timeframe before visual acuity decreasing to 0.175 logMAR, and MMF therapy may not be recommended for patients with low MOG-IgG serum titers. Further long-term follow-up studies are required to validate these findings.

Positive Myelin Oligodendrocyte Glycoprotein Antibodies in Isolated Optic Neuritis in a 14-Year-Old Child

Optic neuritis (ON) is a rare condition in the pediatric age group. Patients with optic neuritis can manifest with a wide range of drops in vision, ranging from mild loss to complete loss of vision. Knowing the cause of optic neuritis is an important point that will affect management and prognosis. Anti-myelin oligodendrocyte glycoprotein (anti-MOG) antibody is an autoantibody that causes demyelination of the central nervous system (CNS). Treatment with a high dose of IV steroids followed by oral steroids is the best regimen that shows a favorable vision outcome. We aim to report this case of isolated optic neuritis with a positive anti-myelin oligodendrocyte glycoprotein antibody to highlight the prognosis of myelin oligodendrocyte glycoprotein disease with isolated optic neuritis and how early diagnosis and treatment can affect the visual outcome.

Acute Optic Neuropathy in Older Adults: Differentiating Between MOGAD Optic Neuritis and Nonarteritic Anterior Ischemic Optic Neuropathy

BACKGROUND AND OBJECTIVES

Myelin oligodendrocyte glycoprotein antibody-associated disease optic neuritis (MOGAD-ON) and nonarteritic anterior ischemic optic neuropathy (NAION) can cause acute optic neuropathy in older adults but have different managements. We aimed to determine differentiating factors between MOGAD-ON and NAION and the frequency of serum MOG-IgG false positivity among patients with NAION.

METHODS

In this international, multicenter, case-control study at tertiary neuro-ophthalmology centers, patients with MOGAD presenting with unilateral optic neuritis as their first attack at age 45 years or older and age-matched and sex-matched patients with NAION were included. Comorbidities, clinical presentations, acute optic disc findings, optical coherence tomography (OCT) findings, and outcomes were compared between MOGAD-ON and NAION. Multivariate analysis was performed to find statistically significant predictors of MOGAD-ON. A separate review of consecutive NAION patients seen at Mayo Clinic, Rochester, from 2018 to 2022, was conducted to estimate the frequency of false-positive MOG-IgG in this population.

RESULTS

Sixty-four patients with unilateral MOGAD-ON were compared with 64 patients with NAION. Among patients with MOGAD-ON, the median age at onset was 56 (interquartile range [IQR] 50-61) years, 70% were female, and 78% were White. Multivariate analysis showed that eye pain was strongly associated with MOGAD-ON (OR 32.905; 95% CI 2.299-473.181), while crowded optic disc (OR 0.033; 95% CI 0.002-0.492) and altitudinal visual field defect (OR 0.028; 95% CI 0.002-0.521) were strongly associated with NAION. On OCT, peripapillary retinal nerve fiber layer (pRNFL) thickness in unilateral MOGAD-ON was lower than in NAION (median 114 vs 201 μm, p < 0.001; median pRNFL thickening 25 vs 102 μm, p < 0.001). MOGAD-ON had more severe vision loss at nadir (median logMAR 1.0 vs 0.3, p < 0.001), but better recovery (median logMAR 0.1 vs 0.3, p = 0.002). In the cohort of consecutive NAION patients, 66/212 (31%) patients with NAION were tested for MOG-IgG and 8% (95% CI 1%-14%) of those had false-positive serum MOG-IgG at low titers.

DISCUSSION

Acute unilateral optic neuropathy with optic disc edema in older adults can be caused by either MOGAD-ON or NAION. Detailed history, the degree of pRNFL swelling on OCT, and visual outcomes can help differentiate the entities and prevent indiscriminate serum MOG-IgG testing in all patients with acute optic neuropathy.

Evaluation of Steroid Pulse Therapy Responsiveness in Myelin-Oligodendrocyte Glycoprotein Antibody-Positive Optic Neuritis

PURPOSE

Myelin-oligodendrocyte glycoprotein antibody-positive optic neuritis (MOGON) is usually responsive to the steroid, but, for some patients, steroid pulse therapy alone may be inadequate. This study aimed to investigate the factors predicting the response to steroid pulse therapy in MOGON.

METHODS

This study included 17 patients (24 eyes) with MOGON, who received single steroid pulse therapy as initial treatment. Best corrected visual acuity (BCVA) and mean deviation (MD) values after treatment were examined concerning findings at onset.

RESULTS

No correlation was found between BCVA at onset and after treatment, but a correlation was observed between MD values at onset and after treatment (correlation coefficient 0.48, p=0.01, Spearman's rank correlation coefficient). Age, gender, duration from onset to treatment, magnetic resonance imaging findings, and optical coherence tomography findings did not affect visual function after treatment.

CONCLUSIONS

Severe visual field impairment at onset may indicate that additional treatment may be necessary.

Monoclonal antibody therapies for aquaporin-4-immunoglobulin G-positive neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease

Monoclonal antibody therapies mark the new era of targeted treatment for relapse prevention in aquaporin-4 (AQP4)-immunoglobulin G (IgG)-positive neuromyelitis optica spectrum disorder (AQP4-IgG+NMOSD). For over a decade, rituximab, an anti-CD20 B-cell-depleting agent, had been the most effectiveness treatment for AQP4-IgG+NMOSD. Tocilizumab, an anti-interleukin-6 receptor, was also observed to be effective. In 2019, several randomized, placebo-controlled trials were completed that demonstrated the remarkable efficacy of eculizumab (anti-C5 complement inhibitor), inebilizumab (anti-CD19 B-cell-depleting agent), and satralizumab (anti-interleukin-6 receptor), leading to the Food and Drug Administration (FDA) approval of specific treatments for AQP4-IgG+NMOSD for the first time. Most recently, ravulizumab (anti-C5 complement inhibitor) was also shown to be highly efficacious in an open-label, external-controlled trial. Although only some patients with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) warrant immunotherapy, there is currently no FDA-approved treatment for relapse prevention in MOGAD. Observational studies showed that tocilizumab was associated with a decrease in relapses, whereas rituximab seemed to have less robust effectiveness in MOGAD compared to AQP4-IgG+NMOSD. Herein, we review the evidence on the efficacy and safety of each monoclonal antibody therapy used in AQP4-IgG+NMOSD and MOGAD, including special considerations in children and women of childbearing potential.

Association of Myelin Oligodendrocyte Glycoprotein Antibody-associated Disease with Coronavirus Disease 2019 Vaccination and Infection: A Case Report of Cortical Encephalitis and Transverse Myelitis Relapse

We herein report a case of myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) that occurred following coronavirus disease 2019 (COVID-19) vaccination and its subsequent relapse after COVID-19 infection. A 34-year-old woman developed cortical encephalitis in the right temporoparietal lobe one week after receiving the mRNA-1273 vaccine. The cerebrospinal fluid was positive for anti-MOG antibody. Her symptoms gradually improved after three courses of intravenous methylprednisolone therapy. Six months later, she experienced a relapse of transverse myelitis following COVID-19 infection. Despite treatment with plasma exchange, the patient remained paralyzed in both lower limbs. We herein review the relationship between MOGAD and COVID-19 vaccination/infection.

An update on optic neuritis

Optic neuritis (ON) is the most common cause of subacute optic neuropathy in young adults. Although most cases of optic neuritis (ON) are classified as typical, meaning idiopathic or associated with multiple sclerosis, there is a growing understanding of atypical forms of optic neuritis such as antibody mediated aquaporin-4 (AQP4)-IgG neuromyelitis optica spectrum disorder (NMOSD) and the recently described entity, myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD). Differentiating typical ON from atypical ON is important because they have different prognoses and treatments. Findings of atypical ON, including severe vision loss with poor recovery with steroids or steroid dependence, prominent optic disc edema, bilateral vision loss, and childhood or late adult onset, should prompt serologic testing for AQP4-IgG and MOG-IgG. Although the traditional division of typical and atypical ON can be helpful, it should be noted that there can be severe presentations of otherwise typical ON and mild presentations of atypical ON that blur these traditional lines. Rare causes of autoimmune optic neuropathies, such as glial fibrillary acidic protein (GFAP) and collapsin response-mediator protein 5 (CRMP5) autoimmunity also should be considered in patients with bilateral painless optic neuropathy associated with optic disc edema, especially if there are other accompanying suggestive neurologic symptoms/signs. Typical ON usually recovers well without treatment, though recovery may be expedited by steroids. Atypical ON is usually treated with intravenous steroids, and some forms, such as NMOSD, often require plasma exchange for acute attacks and long-term immunosuppressive therapy to prevent relapses. Since treatment is tailored to the cause of the ON, elucidating the etiology of the ON is of the utmost importance.

Visual Outcomes Following Plasma Exchange for Optic Neuritis: An International Multicenter Retrospective Analysis of 395 Optic Neuritis Attacks

PURPOSE

To evaluate the effectiveness of plasma exchange (PLEX) for optic neuritis (ON).

METHODS

We conducted an international multicenter retrospective study evaluating the outcomes of ON following PLEX. Outcomes were compared to raw data from the Optic Neuritis Treatment Trial (ONTT) using a matched subset.

RESULTS

A total of 395 ON attack treated with PLEX from 317 patients were evaluated. The median age was 37 years (range 9-75), and 71% were female. Causes of ON included multiple sclerosis (108), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) (92), aquaporin-4-IgG-positive neuromyelitis optica spectrum disorder (AQP4+NMOSD) (75), seronegative-NMOSD (34), idiopathic (83), and other (3). Median time from onset of vision loss to PLEX was 2.6 weeks (interquartile range [IQR], 1.4-4.0). Median visual acuity (VA) at the time of PLEX was count fingers (IQR, 20/200-hand motion), and median final VA was 20/25 (IQR, 20/20-20/60) with no differences among etiologies except MOGAD-ON, which had better outcomes. In 81 (20.5%) ON attacks, the final VA was 20/200 or worse. Patients with poor outcomes were older (P = .002), had worse VA at the time of PLEX (P < .001), and longer delay to PLEX (P < .001). In comparison with the ONTT subset with severe corticosteroid-unresponsive ON, a final VA of worse than 20/40 occurred in 6 of 50 (12%) PLEX-treated ON vs 7 of 19 (37%) from the ONTT treated with intravenous methylprednisolone without PLEX (P = .04).

CONCLUSION

Most ON attacks improved with PLEX, and outcomes were better than attacks with similar severity in the ONTT. The presence of severe vision loss at nadir, older age, and longer delay to PLEX predicted a worse outcome whereas MOGAD-ON had a more favorable prognosis. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

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.

The neuro-ophthalmological manifestations of NMOSD and MOGAD-a comprehensive review

Optic neuritis (ON) is one of the most frequently seen neuro-ophthalmic causes of vision loss worldwide. Typical ON is often idiopathic or seen in patients with multiple sclerosis, which is well described in the landmark clinical trial, the Optic Neuritis Treatment Trial (ONTT). However, since the completion of the ONTT, there has been the discovery of aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) antibodies, which are biomarkers for neuromyelitis optica spectrum disorder (NMOSD) and MOG antibody-associated disease (MOGAD), respectively. These disorders are associated with atypical ON that was not well characterised in the ONTT. The severity, rate of recurrence and overall outcome differs in these two entities requiring prompt and accurate diagnosis and management. This review will summarise the characteristic neuro-ophthalmological signs in NMOSD and MOGAD, serological markers and radiographic findings, as well as acute and long-term therapies used for these disorders.

Novel index, neutrophil percentage (%) is a useful marker for disease activity in MOG antibody-associated disease

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a CNS autoimmune disease affecting the brain, spinal cord, and optic nerve. The neutrophil-to-lymphocyte ratio (NLR) is related to autoimmune disease activity. However, the clinical implication of index ratios such as the NLR is unclear in patients with MOGAD.

OBJECTIVES

We investigated the relationship between index ratios such as the NLR and disease activity and disability to discover the index that best correlates with an attack in MOGAD.

METHODS

Using a CNS demyelinating disease cohort, we reviewed 39 patients with MOGAD (age 37.4 ± 12.0 years; F:M = 20:19) who had 390 blood samples available for cell count analysis. We calculated the NLR, eosinophil-to-lymphocyte-ratio (ELR), platelet-to-lymphocyte-ratio (PLR), monocyte-to-lymphocyte ratio (MLR), basophil-to-lymphocyte ratio (BLR), and neutrophil percentage (N%) [neutrophil count (/mm³) / WBC (/mm³) x 100 (%)]. We investigated the associations between each index ratio and disease activity and disability using the receiver operating characteristic (ROC) curve, machine learning program (kNN algorithm), and generalized estimating equations (GEE) analysis.

RESULTS

In patients with MOGAD, the NLR, PLR, and N% were higher and ELR was lower during an attack than in remission (all p<0.001). The areas under the ROC curve for the NLR, ELR, PLR, and N% were 0.68, 0.69, 0.61, and 0.68, respectively, with the highest sensitivity of 76.0% in the ELR and the highest specificity of 76.3% in the N%. The classification accuracy scores of the kNN machine learning algorithm were 71% for the NLR, 62% for the ELR, 63% for the PLR, and 72% for the N%. In the GEE analysis of attack samples, both the NLR and treatment-naive had positive associations with the Expanded Disability Status Scale (EDSS) score (β=0.137, p = 0.008 and β=1.142, p = 0.003, respectively), and the PLR was negatively associated with the EDSS score (β=-0.004, p = 0.022).

DISCUSSION

Our study suggests that the novel index, neutrophil% is the simplest and the most useful marker to differentiate between attack and remission and shows comparable reliability with NLR in MOGAD. Moreover, the NLR and PLR could be used as supportive biomarkers for disease disability during an attack in patients with MOGAD.

Clinical course, imaging, and pathological features of 45 adult and pediatric cases of myelin oligodendrocyte glycoprotein antibody-associated disease

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently described neuroinflammatory demyelinating disease.

OBJECTIVE

To better understand the clinical spectrum, risk factors and outcomes in MOGAD.

METHODS

Retrospective cohort study including all subjects harboring anti-MOG antibodies identified in major academic hospitals across the province of Quebec.

RESULTS

We identified 45 MOGAD cases. The minimal estimated point-prevalence was 0.52/100 000 in Quebec. Median age at presentation was 32 years (range 1-71) with equal sex ratio. Most frequent ethnic groups were Caucasians and Asians. The most frequent clinical manifestations at onset were optic neuritis (ON), affecting 56% of adults, and acute disseminated encephalomyelitis (ADEM), affecting 33% of children. First MRI was abnormal in 84% of cases. Most CSF samples showed pleocytosis without oligoclonal bands. Two brain biopsies revealed lipid-laden macrophages and reactive astrocytes. Despite steroids, only 38% had fully recovered at 4 weeks after onset. Half of pediatric and two thirds of adult-onset MOGAD subjects experienced relapses. At last follow-up, 69% showed residual deficits, which were moderate to severe in 17% of adults.

CONCLUSION

MOGAD has heterogeneous disease course, and it is not a benign disease for a substantial proportion of adults. Best disease-modifying therapies remain to be determined.

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD): current understanding and challenges

New diagnostic criteria for myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) have recently been proposed, distinguishing this syndrome from other inflammatory diseases of the central nervous system. Seropositivity status for MOG-IgG autoantibodies is important for diagnosing MOGAD, but only in the context of robust clinical characterization and cautious interpretation of neuroimaging. Over the last several years, access to cell-based assay (CBA) techniques has improved diagnostic accuracy, yet the positive predictive value of serum MOG-IgG values varies with the prevalence of MOGAD in any given patient population. For this reason, possible alternative diagnoses need to be considered, and low MOG-IgG titers need to be carefully weighted. In this review, cardinal clinical features of MOGAD are discussed. Key challenges to the current understanding of MOGAD are also highlighted, including uncertainty regarding the specificity and pathogenicity of MOG autoantibodies, the need to identify immunopathologic targets for future therapies, the quest to validate biomarkers that facilitate diagnosis and detect disease activity, and the importance of deciphering which patients with MOGAD require long-term immunotherapy.