Progressive brain atrophy and white matter changes in MOG encephalomyelitis

Frequency, characteristics, predictors and treatment of relapsing myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD)

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) may have a monophasic or relapsing disease course. To date, factors that may predict a relapsing disease course remain largely unknown and only limited data exist regarding the efficacy of different utilized immunotherapy regimens at preventing or reducing relapses.

OBJECTIVES

To assess the characteristics, predictors, and immunotherapy of relapsing MOGAD.

METHODS

This multicenter retrospective analysis included all MOGAD cases at the University of Florida, Baylor College of Medicine and the University of California San Diego with minimum follow-up time of 6 months. Cox proportional hazards regression analyses, corrected for age and sex, were performed to evaluate hazard ratios (HR) of predictors of a relapsing disease course and to compare relapse hazards for utilized immunotherapies.

RESULTS

The majority of included participants (51/79 [64.6 %]) had a relapsing course, and of these individuals, 68.6 % (35/51) experienced their first relapse within the first year. However, 10/51 (19.6 %) participants experienced their first relapse ≥5 years (5-15 years) after the initial presentation. Predictors of a relapsing course were CSF pleocytosis (>150 cells/mm3; HR 3.3 [1.18 - 9.24]; p = 0.023), a pediatric disease onset at age < 9 years (HR 2.69 [1.07-6.75]; p = 0.035), and an initial presentation with the clinical syndrome of meningoencephalitis (HR 3.42 [1.28 - 9.17]; p = 0.015),. In participants with a relapsing course, 13/24 (54.2 %) patients remained relapse-free on rituximab, 4/8 (50 %) on mycophenolate mofetil, and 11/14 (78.6 %) on scheduled immunoglobulins. Patients treated with immunoglobulins had significantly fewer relapses compared to patients treated with other immunotherapies (HR: 0.1 [0.2 - 0.63]; p = 0.014).

CONCLUSIONS

In our cohort, the majority of MOGAD patients relapsed. The initial relapse occurred most frequently within the first year, but first relapses also took place over a decade after the initial presentation. Prepubertal onset, severe CSF pleocytosis, and the clinical syndrome of meningoencephalitis may be predictors of a relapsing course. Of the currently available off-label steroid-sparing treatments, scheduled immunoglobulins may be the most effective in relapse prevention.

Volumetric brain changes in MOGAD: A cross-sectional and longitudinal comparative analysis

BACKGROUND

Relatively little is known about how global and regional brain volumes changes in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) compare with Multiple Sclerosis (MS), Neuromyelitis optica spectrum disorder (NMOSD), and healthy controls (HC).

OBJECTIVE

To compare global and regional brain volumes in MOGAD, MS, NMOSD, and HC cross-sectionally as well as longitudinally in a subset of patients.

METHODS

We retrospectively reviewed all adult MOGAD and NMOSD patients with brain MRI performed in stable remission and compared them with MS patients and HC. Volumetric parameters were assessed using the FDA-approved icobrain software. adjusted for age and sex.

RESULTS

Twenty-four MOGAD, 47 NMOSD, 40 MS patients, and 37 HC were included in the cross-sectional analyses. Relative to HC, the age-adjusted whole brain (WB) volume was significantly lower in patients with MOGAD (p=0.0002), NMOSD (p=0.042), and MS (p=0.01). Longitudinal analysis of a subset of 8 MOGAD, 22 NMOSD, and 34 MS patients showed a reduction in the WB and cortical gray matter (CGM) volumes over time in all three disease groups, without statistically significant differences between groups. The MOGAD group had a greater loss of thalamic volume compared to MS (p=0.028) and NMOSD (p=0.023) and a greater loss of hippocampal volumes compared to MS (p=0.007).

CONCLUSIONS

Age-adjusted WB volume loss was evident in all neuroinflammatory conditions relative to HC in cross-sectional comparisons. In longitudinal analyses, MOGAD patients had a higher thalamic atrophy rate relative to MS and NMOSD, and a higher hippocampal atrophy rate relative to MS. Larger studies are needed to validate these findings and to investigate their clinical implications.

Evidence for and against subclinical disease activity and progressive disease in MOG antibody disease and neuromyelitis optica spectrum disorder

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) and aquaporin-4 IgG seropositive neuromyelitis optica spectrum disorder (AQP4-IgG+ NMOSD) are generally considered to be relapsing disorders, without clinical progression or subclinical disease activity outside of clinical relapses, in contrast to multiple sclerosis (MS). With advances in the diagnosis and treatment of these conditions, prolonged periods of remission without relapses can be achieved, and the question of whether progressive disease courses can occur has re-emerged. In this review, we focus on studies exploring evidence for and against relapse-independent clinical progression and/or subclinical disease activity in patients with MOGAD and AQP4-IgG+ NMOSD.

Myelin Oligodendrocyte Glycoprotein-Immunoglobulin G in the CSF: Clinical Implication of Testing and Association With Disability

Background and Objective

To investigate the clinical relevance of CSF myelin oligodendrocyte glycoprotein-immunoglobulin G (MOG-IgG) testing in a large multicenter cohort.

Methods

In this multicenter cohort study, paired serum-CSF samples from 474 patients with suspected inflammatory demyelinating disease (IDD) from 11 referral hospitals were included. After serum screening, patients were grouped into seropositive myelin oligodendrocyte glycoprotein antibody associated disease (MOGAD, 31), aquaporin-4-IgG-positive neuromyelitis optica spectrum disorder (AQP4-IgG + NMOSD, 60), other IDDs (217), multiple sclerosis (MS, 45), and non-IDDs (121). We then screened CSF for MOG-IgG and compared the clinical and serologic characteristics of patients uniquely positive for MOG-IgG in the CSF to seropositive patients with MOGAD.

Results

Nineteen patients with seropositive MOGAD (61.3%), 9 with other IDDs (CSF MOG + IDD, 4.1%), 4 with MS (8.9%), but none with AQP4-IgG + NMOSD nor with non-IDDs tested positive in the CSF for MOG-IgG. The clinical, pathologic, and prognostic features of patients uniquely positive for CSF MOG-IgG, with a non-MS phenotype, were comparable with those of seropositive MOGAD. Intrathecal MOG-IgG synthesis, observed from the onset of disease, was shown in 12 patients: 4 of 28 who were seropositive and 8 who were uniquely CSF positive, all of whom had involvement of either brain or spinal cord. Both CSF MOG-IgG titer and corrected CSF/serum MOG-IgG index, but not serum MOG-IgG titer, were associated with disability, CSF pleocytosis, and level of CSF proteins.

Discussion

CSF MOG-IgG is found in IDD other than MS and also in MS. In IDD other than MS, the CSF MOG-IgG positivity can support the diagnosis of MOGAD. The synthesis of MOG-IgG in the CNS of patients with MOGAD can be detected from the onset of the disease and is associated with the severity of the disease.

Classification of Evidence

This study provides Class II evidence that the presence of CSF MOG-IgG can improve the diagnosis of MOGAD in the absence of an MS phenotype, and intrathecal synthesis of MOG-IgG was associated with increased disability.

Clinical and Imaging Features of Patients With Encephalitic Symptoms and Myelin Oligodendrocyte Glycoprotein Antibodies

Background

Myelin oligodendrocyte glycoprotein-antibody (MOG-ab)-associated disease (MOGAD) has highly heterogenous clinical and imaging presentations, in which encephalitis is an important phenotype. In recent years, some atypical presentations in MOG-ab-associated encephalitis (MOG-E) have been increasingly reported but have not yet been described well. The aim of the study was to describe the clinical and imaging features of patients with MOG-E in our center. Atypical phenotypes would be reported, which is expected to expand the spectrum of MOGAD.

Methods

We reviewed medical records of 59 patients with MOGAD diagnosed in our center and identified cases who had ever experienced encephalitic symptoms. Three hundred ten patients with autoimmune encephalitis (AE) were also reviewed, and cases with positive MOG-ab were identified. Besides, patients with chronically progressive encephalitis were identified from 13 MOG-E and 310 AE patients. We collected demographic, clinical, laboratory, radiological, and outcome data to explore clinical and imaging characteristics in MOG-E, especially in the atypical phenotype of chronically progressive encephalitis.

Results

We identified 13 patients (7 males, 6 females) with MOG-E. The median age at onset was 33 years (range 13~62 years). Most (9/13, 69.2%) of patients showed acute or subacute onset of encephalitic symptoms. Brain MRI abnormalities were observed in all patients. The most common lesion locations on MRI were cortical/subcortical (11/13, 84.6%), deep/periventricular white matter (10/13, 76.9%) and corpus callosum (4/13, 30.8%). Brain MRI patterns were categorized into four phenotypes. The most common pattern was cortical encephalitis with leptomeningeal enhancement/brain atrophy (10/13, 76.9%). Eight (8/13, 61.5%) patients had a good response to immunotherapy. Four (4/13, 30.8%) patients with chronically progressive course were identified from MOG-E cohort. They showed leukodystrophy-like pattern, multifocal hazy lesions, or cortical encephalitis on MRI. With immunotherapy, they only showed mild or no improvement. We also identified four (4/310, 1.3%) patients with chronically progressive course from AE cohort. They had better outcomes than counterparts in MOG-E.

Conclusions

This study demonstrates that encephalitic presentations in MOGAD had complex clinical patterns. Chronically progressive encephalitis may be a new phenotype of MOGAD. We recommend to test MOG-ab in subacute and chronic progressive dementia with leukodystrophy-like MRI lesions.