Do Early Relapses Predict the Risk of Long-Term Relapsing Disease in an Adult and Paediatric Cohort with MOGAD?

Early Maintenance Treatment Initiation and Relapse Risk Mitigation After a First Event of MOGAD in Adults: The MOGADOR2 Study

BACKGROUND AND OBJECTIVES

Because myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently identified autoimmune disorder, the natural history of MOGAD is still not well described. The objective of this study was to describe the long-term outcomes of adult patients with MOGAD. In addition, we aimed to identify factors affecting relapse risk and neurologic outcomes.

METHODS

Clinical and biological data were obtained from patients with a first event of MOGAD and included in the French nationwide incident cohort between February 2014 and March 2017. Only patients aged 18 years or older at disease onset and with observation period of at least 3 months were included. Data were collected prospectively until July 2023 and registered in the dedicated French nationwide database. This form includes every relapse with phenotype description during follow-up, date of last assessment, final clinical outcome with Expanded Disability Status Scale score and visual acuity, and maintenance therapy. The probability of recurrence-free survival was assessed using the Kaplan-Meier method.

RESULTS

We included 128 patients. The onset phenotype was isolated optic neuritis in 81 patients (63.3%) and isolated myelitis in 25 patients (19.5%). The median follow-up duration was 77.8 months (range 3.2-111.2), with 49 patients (38.3%) experienced at least one relapse. Median times from onset to second and third attacks were 3.2 (1.0-86.2) and 13.0 (2.6-64.4) months, respectively. At the last assessment, Expanded Disability Status Scale Score was ≥3 and ≥6 in 22 (17.2%) and 6 (4.7%) patients, respectively. Eighty patients received at least one maintenance treatment. This treatment was initiated after the first attack in 47 patients (36.7% of the whole cohort) and at the time of a second attack in 25 (19.5%). Multivariate analysis revealed that initiating maintenance treatment after the first attack was associated with a lower relapse risk (OR = 0.26 [95% CI 0.11-0.62], p = 0.002). In patients receiving maintenance therapy after first attack, the 2-year, 4-year, 6-year, and 8-year relapse risks were 11%, 15%, 20%, and 20%, respectively. In other patients, the risks were 41%, 46%, 51%, and 56%.

DISCUSSION

The highest risk of a relapse in MOGAD occurs early, and initiating maintenance therapy from the first attack substantially reduced the relapse risk.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that initiating maintenance therapy from the first attack in patients with MOGAD reduces the relapse risk.

Longitudinal change of serum NfL as disease activity biomarker candidate in MOGAD: A descriptive cohort study

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody (MOG-IgG)-associated disease (MOGAD) is an autoinflammatory disease of the central nervous system. MOGAD often follows a relapsing course that can lead to severe disability, but monophasic disease is possible as well. Currently, there is an unmet clinical need for disease activity biomarkers in MOGAD. Serum neurofilament light chain (sNfL) is a sensitive biomarker for neuroaxonal damage. However, data on longitudinal change of sNfL as disease activity biomarker for MOGAD are scarce.

OBJECTIVE

To describe the longitudinal course of sNfL in adult patients with MOGAD in an active as well as a stable disease state in relation to clinical parameters and serum MOG-IgG titers.

METHODS

We conducted a retrospective, exploratory, monocentric cohort study of adult patients with MOGAD. Cohort 1 consisted of five patients in whom NfL was tested as part of their routine clinical workup, all of which had active disease (maximum 6 months since last attack, median 3 months). Cohort 2 comprised 13 patients, which were tested for NfL in the context of a longitudinal study at predefined time intervals, mostly during remission (median 10 months since last attack). sNfL was measured using single molecule array (Simoa) technology at least at two time points (median 3) within a median observation time of 5 months in cohort 1, and at baseline and after a median duration of 12 months in cohort 2. MOG-IgG titers were measured by a fixed cell-based assay.

RESULTS

Change in sNfL correlated positively with change in MOG-IgG titers (rho=0.59, p = 0.027). The variability of sNfL (difference between highest and lowest level) during the observation period was higher in patients who had an attack within six months before baseline (median 37 [interquartile range [IQR] 10-64] pg/ml vs. 2.3 [IQR 1-5] pg/ml, p = 0.006). sNfL increased in patients with an attack during the observation period. Patients with baseline sNfL measurement within two weeks after attack symptom onset displayed relatively low initial sNfL with an increase afterwards.

CONCLUSIONS

Longitudinal sNfL change correlates with MOG-IgG titer change and may be a promising biomarker candidate for disease activity in MOGAD. Increasing sNfL levels might be utilized to adjudicate suspected attacks. In acute attacks, sNfL increase may occur with a delay after symptom onset.

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.

Myelin Oligodendrocyte Glycoprotein-Antibody Associated Disease: An Updated Review of the Clinical Spectrum, Pathogenetic Mechanisms and Therapeutic Management

Clinical syndromes associated with antibodies against myelin oligodendrocyte glycoprotein (MOG) are now recognized as a distinct neurological disease entity, and are gaining increasing attention. The pathogenic mechanisms underlying MOG-antibody disease (MOGAD) remain incompletely understood. Case series, facilitated by registries, and observational studies over the past few years have shed increasing light on the clinical aspects and therapeutic approaches of MOGAD. MOGAD may manifest with a variety of clinical syndromes, including acute disseminated encephalomyelitis (ADEM), autoimmune encephalitis, optic neuritis (ON) and transverse myelitis (TM). MOGAD can be either monophasic or relapsing. This review aims to provide a comprehensive updated description of the clinical spectrum, paraclinical features, and prognosis of MOG-antibody disease, as well as summarize its therapeutic considerations. Randomized clinical trials, standardized diagnostic criteria and treatment guidelines are the steps forward.

Oral corticosteroid dosage and taper duration at onset in myelin oligodendrocyte glycoprotein antibody-associated disease influences time to first relapse

BACKGROUND

We sought to identify an optimal oral corticosteroid regimen at the onset of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), which would delay time to first relapse while minimising cumulative corticosteroid exposure.

METHODS

In a retrospective multicentre cohort study, Cox proportional hazards models examined the relationship between corticosteroid course as a time-varying covariate and time to first relapse. Simon-Makuch and Kaplan-Meier plots identified an optimal dosing strategy.

RESULTS

We evaluated 109 patients (62 female, 57%; 41 paediatric, 38%; median age at onset 26 years, (IQR 8-38); median follow-up 6.2 years (IQR 2.6-9.6)). 76/109 (70%) experienced a relapse (median time to first relapse 13.7 months; 95% CI 8.2 to 37.9). In a multivariable model, higher doses of oral prednisone delayed time to first relapse with an effect estimate of 3.7% (95% CI 0.8% to 6.6%; p=0.014) reduced hazard of relapse for every 1 mg/day dose increment. There was evidence of reduced hazard of relapse for patients dosed ≥12.5 mg/day (HR 0.21, 95% CI 0.07 to 0.6; p=0.0036), corresponding to a 79% reduction in relapse risk. There was evidence of reduced hazard of relapse for those dosed ≥12.5 mg/day for at least 3 months (HR 0.12, 95% CI 0.03 to 0.44; p=0.0012), corresponding to an 88% reduction in relapse risk compared with those never treated in this range. No patient with this recommended dosing at onset experienced a Common Terminology Criteria for Adverse Events grade >3 adverse effect.

CONCLUSIONS

The optimal dose of 12.5 mg of prednisone daily in adults (0.16 mg/kg/day for children) for a minimum of 3 months at the onset of MOGAD delays time to first relapse.

The MOG antibody non-P42 epitope is predictive of a relapsing course in MOG antibody-associated disease

BACKGROUND

Myelin oligodendrocyte glycoprotein (MOG) IgG seropositivity is a prerequisite for MOG antibody-associated disease (MOGAD) diagnosis. While a significant proportion of patients experience a relapsing disease, there is currently no biomarker predictive of disease course. We aim to determine whether MOG-IgG epitopes can predict a relapsing course in MOGAD patients.

METHODS

MOG-IgG-seropositive confirmed adult MOGAD patients were included (n=202). Serum MOG-IgG and epitope binding were determined by validated flow cytometry live cell-based assays. Associations between epitopes, disease course, clinical phenotype, Expanded Disability Status Scale and Visual Functional System Score at onset and last review were evaluated.

RESULTS

Of 202 MOGAD patients, 150 (74%) patients had MOG-IgG that recognised the immunodominant proline42 (P42) epitope and 115 (57%) recognised histidine103/serine104 (H103/S104). Fifty-two (26%) patients had non-P42 MOG-IgG and showed an increased risk of a relapsing course (HR 1.7; 95% CI 1.15 to 2.60, p=0.009). Relapse-freedom was shorter in patients with non-P42 MOG-IgG (p=0.0079). Non-P42 MOG-IgG epitope status remained unchanged from onset throughout the disease course and was a strong predictor of a relapsing course in patients with unilateral optic neuritis (HR 2.7, 95% CI 1.06 to 6.98, p=0.038), with high specificity (95%, 95% CI 77% to 100%) and positive predictive value (85%, 95% CI 45% to 98%).

CONCLUSIONS

Non-P42 MOG-IgG predicts a relapsing course in a significant subgroup of MOGAD patients. Patients with unilateral optic neuritis, the most frequent MOGAD phenotype, can reliably be tested at onset, regardless of age and sex. Early detection and specialised management in these patients could minimise disability and improve long-term outcomes.

Visual outcome measures in pediatric myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD)

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) comprises various age-dependent clinical phenotypes and may be monophasic, multiphasic, or chronic. Optic neuritis (ON) is a common manifestation and frequently appears in combination with other MOGAD phenotypes, particularly in young children. Despite permanent structural damage to the retinal nerve fiber layer (RNFL), children often experience complete visual recovery.

AIMS

To analyze the progression and impact of MOGAD on the visual system of pediatric patients independently of the history of ON.

METHODS

This retrospective study included children who met specific criteria: myelin oligodendrocyte glycoprotein (MOG) immunoglobulin G (IgG) seropositivity, acute presentation of MOGAD, and written general consent. Main outcome measures were global peripapillary retinal nerve fiber layer (pRNFL) thickness, and near and distance visual acuity, analyzed using descriptive statistics.

RESULTS

We identified 10 patients with median age of 7.7 years at first event: 7 patients manifested with acute disseminated encephalomyelitis (ADEM) (with ON 5/7, ADEM only 1/7, with transverse myelitis (TM) 1/7), 2 with isolated ON, and 1 patient with neuromyelitis optica spectrum disorder (NMOSD)-like phenotype with ON. Among ON patients, 5/8 were affected bilaterally, with 3 initially diagnosed with unilateral ON but experiencing subsequent involvement of the fellow eye. None of the patients without previous ON showed a deterioration of visual acuity and, if evaluated, a reduction of the pRNFL.

CONCLUSION

Most pediatric MOGAD-ON patients in our cohort presented with acute vison loss and optic disc edema. All patients achieved complete visual recovery, independent of number of relapses or initial visual loss. The pRNFL thickness decreased for several months and stabilized at reduced levels after 12 months in the absence of further relapses. MOGAD may not have subclinical/'silent' effects on the visual system, as visual acuity and pRNFL were not affected in patients without ON.