Impact of rituximab treatment regime on time to relapse in aquaporin-4 antibody positive neuromyelitis optica spectrum disorder

BACKGROUND

Aquaporin-4 (AQP4) antibody associated neuromyelitis optica (NMOSD) requires long-term immunosuppression. Rituximab is increasingly used worldwide, however the optimal regime is not established.

METHODS

We retrospectively examined different rituximab regimens in AQP4-NMOSD. Standard monotherapy (SM; 6 monthly infusions), SM plus oral steroids (SM+S), extended interval dosing (EID; guided by CD19 repopulation) and EID with oral steroids (EID+S) were compared. The primary outcome was time to first clinical relapse. Potential confounders including age, gender, number of previous relapses, and onset phenotype were included.

RESULTS

77 patients were included: 67 females, median onset age 35.6, median DSS at rituximab initiation 5.0. 39 were on SM+S, 20 SM, 6 EID, and 12 EID+S. 25/77 patients relapsed during a median follow-up of 44.0 months. No significant difference in time to first relapse was observed between any rituximab regimen. Pooled analyses to compare regimens that use standard monotherapy (SM and SM+S) against those that use extended interval dosing (EID and EID+S) showed no significant difference. Pooled analysis of regimens using steroids with those not using steroids also showed no significant difference. Adjusted Cox proportional hazard model revealed no significant difference between rituximab regimens or influence of demographic factors. 9 significant adverse events were recorded, 5 in the SM group and 4 in SM+S.

CONCLUSIONS

This study provides some basis for further exploring EID as a viable option for long term treatment of AQP4-NMOSD. This may improve patient experience and consolidate use of hospital resources.

The absence of antibodies in longitudinally extensive transverse myelitis may predict a more favourable prognosis

BACKGROUND

Isolated first episodes of longitudinally extensive transverse myelitis (LETM) have typically been associated with neuromyelitis optica spectrum disorder (NMOSD) or myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). However, in some cases, serological testing and screening for other aetiologies are negative, a condition referred to as double seronegative longitudinally extensive transverse myelitis (dsLETM).

OBJECTIVE

The objective of this study was to evaluate comparative outcomes of dsLETM, MOGAD-LETM and NMOSD-LETM.

METHODS

Cohort study of LETM cases seen in the UK NMOSD Highly Specialised Service between January 2008 and March 2022.

RESULTS

LETM = 87 cases were identified (median onset age = 46 years (15-85); median follow-up = 46 months (1-144); 47% NMOSD-LETM = 41 (aquaporin-4 antibodies (AQP4-IgG) positive = 36), 20% MOGAD-LETM = 17 and 33% dsLETM = 29). Despite similar Expanded Disability Status Scale (EDSS) at nadir, last EDSS was higher in AQP4-IgG and seronegative NMOSD-LETM (sNMOSD) (p = 0.006). Relapses were less common in dsLETM compared to AQP4-IgG NMOSD-LETM and sNMOSD-LETM (19% vs 60% vs 100%; p = 0.001). Poor prognosis could be predicted by AQP4-IgG (odds ratio (OR) = 38.86 (95% confidence interval (CI) = 1.36-1112.86); p = 0.03) and EDSS 3 months after onset (OR = 65.85 (95% CI = 3.65-1188.60); p = 0.005).

CONCLUSION

dsLETM remains clinically challenging and difficult to classify with existing nosological terminology. Despite a similar EDSS at nadir, patients with dsLETM relapsed less and had a better long-term prognosis than NMOSD-LETM.

Predictors of azathioprine and mycophenolate mofetil response in patients with neuromyelitis optica spectrum disorder: A cohort study

BACKGROUND

Relapse rates of 47 % have been reported in patients with neuromyelitis optica (NMOSD) using Azathioprine (AZA) and mycophenolate mofetil (MMF). Prediction of non-responders could help determine which patients are most likely to benefit from newer monoclonal antibody treatments from the outset.

OBJECTIVES

To identify predictors of AZA and MMF treatment response in NMOSD.

METHODS

Multicenter cohort study of NMOSD patients from Brazil and the United Kingdom, treated with AZA and MMF. An unsatisfactory response was defined as one severe or two non-severe attacks in a year. Cox regression was used to identify predictive factors of unsatisfactory response to AZA and MMF.

RESULTS

103 NMOSD patients, mean age 38 years, 83% female, and 65% of Black ethnic group were included. An unsatisfactory IS response was observed in 42% of patients over 2.5 years (IQR 1.0-8.8) years. A severe preceding attack was more common in non-responders (31.1% x 76.7%, p = <0.001). In multivariable analysis, severe attack (RR 3.13; 95 % CI 1.37-7.18, p = 0.007) or higher annualized relapse rate (RR 4.84; 95 % CI 2.01-11.65, p = < 0.001) predicted an unsatisfactory response. Interestingly, Black NMOSD patients had a lower risk of poor response (RR 0.39, 95 % CI 0.17-0.85, p = 0.019).

CONCLUSION

Severe attack and a higher annualized relapse rate before AZA or MMF initiation were associated with an unsatisfactory IS response. In patients with these characteristics, treatment with higher-efficacy drugs should be considered from the outset.

Risks and outcomes of pregnancy in neuromyelitis optica spectrum disorder: A comprehensive review

Neuromyelitis optica spectrum disorder (NMOSD) is a rare central nervous system autoimmune disease. Aquaporin-4 antibody (AQP4-IgG) is present in over 75% of cases and criteria also exist for the diagnosis of seronegative NMOSD. AQP4-IgG NMOSD has a strong female predominance (9:1 ratio), with a median onset age of 40 years. Pregnancy in those with NMOSD is therefore an important topic. Fecundity in NMOSD is likely impaired, and for females who conceive, obstetric complications including miscarriages and pre-eclampsia are significantly higher in NMOSD compared to the general population and in related conditions such as multiple sclerosis (MS). In contrast to MS, NMOSD disease activity does not subside during pregnancy. Also, relapse risk substantially rises above pre-pregnancy rates in the early postpartum period. In view of the evolving landscape of NMOSD, we provide a contemporary update of the impacts of pregnancy in NMOSD.

Timing of MOG-IgG Testing Is Key to 2023 MOGAD Diagnostic Criteria

BACKGROUND AND OBJECTIVES

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is a recently identified autoimmune demyelinating disorder of the CNS affecting both adults and children. Diagnostic criteria for MOGAD have recently been published. We aimed to validate the 2023 MOGAD diagnostic criteria in a real-world cohort of patients with atypical CNS inflammation.

METHODS

All patients referred to the National neuromyelitis optica spectrum disorder (NMOSD) specialized service at The Walton Center NHS Foundation Trust between 2012 and 2023 with an atypical demyelinating syndrome were evaluated. We systematically applied the 2023 MOGAD diagnostic criteria and previous 2018 International Diagnostic Recommendations for MOG encephalomyelitis to our retrospective cohort.

RESULTS

474 patients were screened and 66 were excluded for lack of clinical information. Preexisting diagnoses within our cohort included the following: MOGAD, n = 127; AQP4-IgG NMOSD, n = 125; seronegative NMOSD, n = 33; multiple sclerosis (MS), n = 10; and other diagnoses, n = 113. Of patients with preexisting MOGAD, 97% (123/127) fulfilled the 2023 MOGAD diagnostic criteria. Three patients with a low-positive MOG-IgG did not meet supportive features though 2/3 had insufficient investigations. Alternative diagnoses could not be excluded in 1 patient with MS-MOGAD overlap. No patients with a non-MOGAD diagnosis were found to fulfill the 2023 diagnostic criteria. The sensitivity and specificity of the 2023 MOGAD diagnostic criteria were 97% and 100% with no false positives, improving on 2018 International Diagnostic Recommendations for MOG encephalomyelitis. Low-positive MOG-IgG results were more often associated with a longer time from disease onset to sampling (p < 0.001). In addition, in patients with a MOG-IgG1 test within 6 months of clinical onset, approximately 25% can become low positive by 6 months. Of patients with preexisting MOGAD, 9% (12/127) had insufficient investigations and examinations to fully evaluate additional supportive features. However, in those who were completely evaluated, supportive features were fulfilled in 97% (111/115).

DISCUSSION

The 2023 MOGAD diagnostic criteria were highly sensitive and specific and closely align with historically established cases of MOGAD. However, because additional supportive features are stipulated for patients with a low-positive MOG-IgG result, missed diagnoses may occur due to delayed testing or insufficient investigations.

A comprehensive review of the advances in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare relapsing neuroinflammatory autoimmune astrocytopathy, with a predilection for the optic nerves and spinal cord. Most cases are characterised by aquaporin-4-antibody positivity and have a relapsing disease course, which is associated with accrual of disability. Although the prognosis in NMOSD has improved markedly over the past few years owing to advances in diagnosis and therapeutics, it remains a severe disease. In this article, we review the evolution of our understanding of NMOSD, its pathogenesis, clinical features, disease course, treatment options and associated symptoms. We also address the gaps in knowledge and areas for future research focus.

Do we still need OCBs in MS diagnosis and how many?

BACKGROUND

CSF-specific oligoclonal bands (CSF-OCBs) can be used for dissemination in time (DIT) in the 2017 multiple sclerosis (MS) diagnostic criteria. A cut-off of ≥2 CSF-OCBs was recommended but studies have suggested ≥3 CSF-OCBs may be superior.

OBJECTIVES

To assess utility of ≥2 and ≥3 CSF-OCBs as a cut-off for MS diagnosis.

METHODS

Paired serum and CSF-OCBs sent to the Walton Centre, UK between July 2018 and June 2020 were included. CSF-OCBs were assessed using isoelectric focussing and reviewed by two blinded raters. Case records were reviewed.

RESULTS

Of 1334 paired serum and CSF-OCB requests, 945 cases had sufficient clinical information. More than 1 CSF-OCB was detected in 268/945(28%) cases. Of these, 252 had ≥2 and 230 had ≥3 CSF-OCBs. The sensitivity and specificity for MS with ≥2 and ≥3 CSF-OCBs were 91.7%, 91.2%, 90.2% and 93.8% respectively. Only 3/22 patients with 2 CSF-OCBs had MS. In 25% of patients, CSF-OCBs reduced time to MS diagnosis (median 437.5 days (28-1332)).

CONCLUSION

Although cut-offs of ≥2 or ≥3 CSF-OCBs performed similarly well, 2 CSF-OCBs were frequently seen with non-inflammatory pathology. Use of ≥3 CSF-OCBs for MS diagnosis should be considered. CSF analysis reduced time to MS diagnosis by approximately 14 months.

IgG1-3 MuSK Antibodies Inhibit AChR Cluster Formation, Restored by SHP2 Inhibitor, Despite Normal MuSK, DOK7, or AChR Subunit Phosphorylation

BACKGROUND AND OBJECTIVES

Up to 50% of patients with myasthenia gravis (MG) without acetylcholine receptor antibodies (AChR-Abs) have antibodies to muscle-specific kinase (MuSK). Most MuSK antibodies (MuSK-Abs) are IgG4 and inhibit agrin-induced MuSK phosphorylation, leading to impaired clustering of AChRs at the developing or mature neuromuscular junction. However, IgG1-3 MuSK-Abs also exist in MuSK-MG patients, and their potential mechanisms have not been explored fully.

METHODS

C2C12 myotubes were exposed to MuSK-MG plasma IgG1-3 or IgG4, with or without purified agrin. MuSK, Downstream of Kinase 7 (DOK7), and βAChR were immunoprecipitated and their phosphorylation levels identified by immunoblotting. Agrin and agrin-independent AChR clusters were measured by immunofluorescence and AChR numbers by binding of 125I-α-bungarotoxin. Transcriptomic analysis was performed on treated myotubes.

RESULTS

IgG1-3 MuSK-Abs impaired AChR clustering without inhibiting agrin-induced MuSK phosphorylation. Moreover, the well-established pathway initiated by MuSK through DOK7, resulting in βAChR phosphorylation, was not impaired by MuSK-IgG1-3 and was agrin-independent. Nevertheless, the AChR clusters did not form, and both the number of AChR microclusters that precede full cluster formation and the myotube surface AChRs were reduced. Transcriptomic analysis did not throw light on the pathways involved. However, the SHP2 inhibitor, NSC-87877, increased the number of microclusters and led to fully formed AChR clusters.

DISCUSSION

MuSK-IgG1-3 is pathogenic but seems to act through a noncanonical pathway. Further studies should throw light on the mechanisms involved at the neuromuscular junction.

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

OBJECTIVE

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) can be monophasic or relapsing, with early relapse being a feature. However, the relevance of early relapse on longer-term relapse risk is unknown. Here, we investigate whether early relapses increase longer-term relapse risk in patients with MOGAD.

METHODS

A retrospective analysis of 289 adult- and pediatric-onset patients with MOGAD followed for at least 2 years in 6 specialized referral centers. "Early relapses" were defined as attacks within the first 12 months from onset, with "very early relapses" defined within 30 to 90 days from onset and "delayed early relapses" defined within 90 to 365 days. "Long-term relapses" were defined as relapses beyond 12 months. Cox regression modeling and Kaplan-Meier survival analysis were used to estimate the long-term relapse risk and rate.

RESULTS

Sixty-seven patients (23.2%) had early relapses with a median number of 1 event. Univariate analysis revealed an elevated risk for long-term relapses if any "early relapses" were present (hazard ratio [HR] = 2.11, p < 0.001), whether occurring during the first 3 months (HR = 2.70, p < 0.001) or the remaining 9 months (HR = 1.88, p = 0.001), with similar results yielded in the multivariate analysis. In children with onset below aged 12 years, only delayed early relapses were associated with an increased risk of long-term relapses (HR = 2.64, p = 0.026).

INTERPRETATION

The presence of very early relapses and delayed early relapses within 12 months of onset in patients with MOGAD increases the risk of long-term relapsing disease, whereas a relapse within 90 days appears not to indicate a chronic inflammatory process in young pediatric-onset disease. ANN NEUROL 2023;94:508-517.

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.

International Delphi Consensus on the Management of AQP4-IgG+ NMOSD: Recommendations for Eculizumab, Inebilizumab, and Satralizumab

BACKGROUND AND OBJECTIVES

Neuromyelitis optica spectrum disorder (NMOSD) is a rare debilitating autoimmune disease of the CNS. Three monoclonal antibodies were recently approved as maintenance therapies for aquaporin-4 immunoglobulin G (AQP4-IgG)-seropositive NMOSD (eculizumab, inebilizumab, and satralizumab), prompting the need to consider best practice therapeutic decision-making for this indication. Our objective was to develop validated statements for the management of AQP4-IgG-seropositive NMOSD, through an evidence-based Delphi consensus process, with a focus on recommendations for eculizumab, inebilizumab, and satralizumab.

METHODS

We recruited an international panel of clinical experts in NMOSD and asked them to complete a questionnaire on NMOSD management. Panel members received a summary of evidence identified through a targeted literature review and provided free-text responses to the questionnaire based on both the data provided and their clinical experience. Responses were used to generate draft statements on NMOSD-related themes. Statements were voted on over a maximum of 3 rounds; participation in at least 1 of the first 2 rounds was mandatory. Panel members anonymously provided their level of agreement (6-point Likert scale) on each statement. Statements that failed to reach a predefined consensus threshold (≥67%) were revised based on feedback and then voted on in the next round. Final statements were those that met the consensus threshold (≥67%).

RESULTS

The Delphi panel comprised 24 experts, who completed the Delphi process in November 2021 after 2 voting rounds. In round 1, 23/25 statements reached consensus and were accepted as final. The 2 statements that failed to reach consensus were revised. In round 2, both revised statements reached consensus. Twenty-five statements were agreed in total: 11 on initiation of or switching between eculizumab, inebilizumab, and satralizumab; 3 on monotherapy/combination therapy; 7 on safety and patient population considerations; 3 on biomarkers/patient-reported outcomes; and 1 on research gaps.

DISCUSSION

An established consensus method was used to develop statements relevant to the management of AQP4-IgG-seropositive NMOSD. These international statements will be valuable for informing individualized therapeutic decision-making and could form the basis for standardized practice guidelines.

Diagnostic value of intereye difference metrics for optic neuritis in aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorders

BACKGROUND

The novel optic neuritis (ON) diagnostic criteria include intereye differences (IED) of optical coherence tomography (OCT) parameters. IED has proven valuable for ON diagnosis in multiple sclerosis but has not been evaluated in aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorders (AQP4+NMOSD). We evaluated the diagnostic accuracy of intereye absolute (IEAD) and percentage difference (IEPD) in AQP4+NMOSD after unilateral ON >6 months before OCT as compared with healthy controls (HC).

METHODS

Twenty-eight AQP4+NMOSD after unilateral ON (NMOSD-ON), 62 HC and 45 AQP4+NMOSD without ON history (NMOSD-NON) were recruited by 13 centres as part of the international Collaborative Retrospective Study on retinal OCT in Neuromyelitis Optica study. Mean thickness of peripapillary retinal nerve fibre layer (pRNFL) and macular ganglion cell and inner plexiform layer (GCIPL) were quantified by Spectralis spectral domain OCT. Threshold values of the ON diagnostic criteria (pRNFL: IEAD 5 µm, IEPD 5%; GCIPL: IEAD: 4 µm, IEPD: 4%) were evaluated using receiver operating characteristics and area under the curve (AUC) metrics.

RESULTS

The discriminative power was high for NMOSD-ON versus HC for IEAD (pRNFL: AUC 0.95, specificity 82%, sensitivity 86%; GCIPL: AUC 0.93, specificity 98%, sensitivity 75%) and IEPD (pRNFL: AUC 0.96, specificity 87%, sensitivity 89%; GCIPL: AUC 0.94, specificity 96%, sensitivity 82%). The discriminative power was high/moderate for NMOSD-ON versus NMOSD-NON for IEAD (pRNFL: AUC 0.92, specificity 77%, sensitivity 86%; GCIP: AUC 0.87, specificity 85%, sensitivity 75%) and for IEPD (pRNFL: AUC 0.94, specificity 82%, sensitivity 89%; GCIP: AUC 0.88, specificity 82%, sensitivity 82%).

CONCLUSIONS

Results support the validation of the IED metrics as OCT parameters of the novel diagnostic ON criteria in AQP4+NMOSD.

Acute Inflammatory Diseases of the Central Nervous System After SARS-CoV-2 Vaccination

BACKGROUND AND OBJECTIVES

Acute inflammatory CNS diseases include neuromyelitis optica spectrum disorders (NMOSDs) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Both MOGAD and acute disseminated encephalomyelitis (ADEM) have been reported after vaccination. Consequently, the mass SARS-CoV-2 vaccination program could result in increased rates of these conditions. We described the features of patients presenting with new acute CNS demyelination resembling NMOSDs or MOGAD within 8 weeks of SARS-CoV-2 vaccination.

METHODS

The study included a prospective case series of patients referred to highly specialized NMOSD services in the UK from the introduction of SARS-CoV-2 vaccination program up to May 2022. Twenty-five patients presented with new optic neuritis (ON) and/or transverse myelitis (TM) ± other CNS inflammation within 8 weeks of vaccination with either AstraZeneca (ChAdOx1S) or Pfizer (BNT162b2) vaccines. Their clinical records and paraclinical investigations including MRI scans were reviewed. Serologic testing for antibodies to myelin oligodendrocyte glycoprotein (MOG) and aquaporin 4 (AQP4) was performed using live cell-based assays. Patients' outcomes were graded good, moderate, or poor based on the last clinical assessment.

RESULTS

Of 25 patients identified (median age 38 years, 14 female), 12 (48%) had MOG antibodies (MOGIgG+), 2 (8%) had aquaporin 4 antibodies (AQP4IgG+), and 11 (44%) had neither. Twelve of 14 (86%) antibody-positive patients received the ChAdOx1S vaccine. MOGIgG+ patients presented most commonly with TM (10/12, 83%), frequently in combination with ADEM-like brain/brainstem lesions (6/12, 50%). Transverse myelitis was longitudinally extensive in 7 of the 10 patients. A peak in new MOGAD cases in Spring 2021 was attributable to postvaccine cases. Both AQP4IgG+ patients presented with brain lesions and TM. Four of 6 (67%) seronegative ChAdOx1S recipients experienced longitudinally extensive TM (LETM) compared with 1 of 5 (20%) of the BNT162b2 group, and facial nerve inflammation was reported only in ChAdOx1S recipients (2/5, 40%). Guillain-Barre syndrome was confirmed in 1 seronegative ChAdOx1S recipient and suspected in another.

DISCUSSION

ChAdOx1S was associated with 12/14 antibody-positive cases, the majority MOGAD. MOGAD patients presented atypically, only 2 with isolated ON (1 after BNT162b2 vaccine) but with frequent ADEM-like brain lesions and LETM. Within the seronegative group, phenotypic differences were observed between ChAdOx1S and BNT162b2 recipients. These observations might support a causative role of the ChAdOx1S vaccine in inflammatory CNS disease and particularly MOGAD. Further study of this cohort could provide insights into vaccine-associated immunopathology.

Acute inflammatory CNS diseases following vaccination against SARS-CoV-2

Background

Vaccination is a recognised trigger of ADEM and approximately 50% paediatric cases have antibodies to MOG. The SARS-CoV-2 mass vaccination programme could therefore trigger cases of MOGAD. Neuromyelitis optica (NMO) is an autoimmune inflammatory condition of the CNS associ- ated with antibodies to AQP4.

Method

Ten patients (ages 22 – 65 years) with antibodies to MOG or AQP4 were referred to the NHS England NMO service having developed acute onset CNS inflammation within 8 weeks of vaccination.

Results

Eight patients had MOGAD, seven of whom received the AstraZeneca vaccine (AZV) and one the Pfizer vaccine (PV). Only the post-PV MOGAD patient presented with typical adult-onset phenotype of isolated ON. All post-AZV MOGAD patients presented atypically; 85.7% had LETM and 71.4% had intrac- erebral lesions, resembling ADEM more commonly seen in paediatric MOGAD. The atypical presentation supports a causative role of AZV, but the role of PV is less convincing.

Two patients had AQP4-NMOSD with typical demographic features. Both received AZV. Less typically, one young adult presented with LETM rather than characteristic young adult ON, the other had a silent short segment myelitis, which is rarely seen in AQP4-NMOSD. Both patients achieved good outcomes.

Conclusion

We discuss the potential causation and pathophysiological mechanisms.

Impact of rituximab regime on time to relapse in aquaporin-4 antibody positive neuromyelitis spectrum disorder

Background

Aquaporin-4 (AQP4) antibody associated neuromyelitis optica spectrum disorder (NMOSD) requires long-term immunomodulation. In refractory cases rituximab can be used, however the optimal regime is not established.

Methods

We retrospectively examined different rituximab regimes in AQP4-NMOSD. Standard mono- therapy (SM; 6 monthly infusions), SM plus oral steroids (SM+S), extended interval dosing (EID; with retreat- ment at CD19 >1%) and EID with oral steroids (EID+S) were compared. The primary outcome was time to first clinical relapse. Potential confounders including age, gender, number of previous relapses, and onset phenotype were included.

Results

77 patients were included: 67 females, mean age 34.6, median DSS at rituximab initiation 5.0. 40 were on SM+S, 19 on SM, 8 on EID, and 10 on EID+S, with mean follow-up 38.5 months. 25/77 patients relapsed on rituximab. Median time to first relapse was 39 months (SM+S), 46 months (SM), 54 months (EID) and 42 months (EID+S). Adjusted Cox proportional hazard model revealed no significant difference between rituximab regimes (SM+S as reference; hazard ratio for SM 1.39, 95%CI 0.49–4.1, p=0.55; hazard ratio for EID 0.70, 95%CI 0.15–3.3, p=0.65; hazard ratio for EID+S 1.63, 95%CI 0.48–5.5, p=0.43). 9 significant infections were recorded, 3 in the SM group and 6 in SM+S.

Conclusions

This provides initial evidence that EID could be used for long term treatment of NMOSD. This may improve patient experience and consolidate use of hospital resources.

Progressive myelin oligodendrocyte glycoprotein-associated demyelination mimicking leukodystrophy

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) may be associated with relapsing disease, but clinical progression independent of relapse activity is rare.

OBJECTIVES

To report progressive disease in a patient with MOGAD.

METHODS

A single retrospective case report.

RESULTS

At 4 years of age, the patient had a single episode of acute disseminated encephalomyelitis. She remained well until age 17 years but over the next 9 years developed progressive spastic quadriparesis, cognitive and bulbar dysfunction. Brain imaging showed a leukodystrophy-like pattern of white matter abnormality with contrast enhancement at different time points. Myelin oligodendrocyte glycoprotein (MOG)-IgG was repeatedly positive by live cell-based assay.

CONCLUSION

Secondary progression may be a rare presentation of MOG-IgG-associated disease.

Prognostic indicators and outcomes of hospitalised COVID-19 patients with neurological disease: An individual patient data meta-analysis

Background

Neurological COVID-19 disease has been reported widely, but published studies often lack information on neurological outcomes and prognostic risk factors. We aimed to describe the spectrum of neurological disease in hospitalised COVID-19 patients; characterise clinical outcomes; and investigate factors associated with a poor outcome.

Methods

We conducted an individual patient data (IPD) meta-analysis of hospitalised patients with neurological COVID-19 disease, using standard case definitions. We invited authors of studies from the first pandemic wave, plus clinicians in the Global COVID-Neuro Network with unpublished data, to contribute. We analysed features associated with poor outcome (moderate to severe disability or death, 3 to 6 on the modified Rankin Scale) using multivariable models.

Results

We included 83 studies (31 unpublished) providing IPD for 1979 patients with COVID-19 and acute new-onset neurological disease. Encephalopathy (978 [49%] patients) and cerebrovascular events (506 [26%]) were the most common diagnoses. Respiratory and systemic symptoms preceded neurological features in 93% of patients; one third developed neurological disease after hospital admission. A poor outcome was more common in patients with cerebrovascular events (76% [95% CI 67–82]), than encephalopathy (54% [42–65]). Intensive care use was high (38% [35–41]) overall, and also greater in the cerebrovascular patients. In the cerebrovascular, but not encephalopathic patients, risk factors for poor outcome included breathlessness on admission and elevated D-dimer. Overall, 30-day mortality was 30% [27–32]. The hazard of death was comparatively lower for patients in the WHO European region.

Interpretation

Neurological COVID-19 disease poses a considerable burden in terms of disease outcomes and use of hospital resources from prolonged intensive care and inpatient admission; preliminary data suggest these may differ according to WHO regions and country income levels. The different risk factors for encephalopathy and stroke suggest different disease mechanisms which may be amenable to intervention, especially in those who develop neurological symptoms after hospital admission.

071 Causes of death in AQP4-IgG neuromyelitis optica spectrum disorder

Objective

To evaluate causes of death in Aquaporin-4 antibody positive Neuromyelitis Optica Spectrum Disorder (AQP4-IgG NMOSD) patients treated in the National NMOSD service.

Method

Retrospective review of Liverpool and Oxford patient databases (NMOSD national referral centres) between January 2010–2020.

Results

AQP4-IgG NMOSD=414 patients attended the NMOSD Service and 34 died. Of these, 32/34(94%) were female with a median disease duration of 10 years (0.5–19.1). The median age at death was 67.1(45.1–88.3) years. Median EDSS score prior to death was 8(2–9.5). The median number of relapses from disease onset to death was 3(0–10), with 94% of patients experiencing at least 1 relapse. All but one patient was immunosuppressed (Azathioprine=15, Mycophenolate=3, Rituximab=7, Methotrexate=4, IVIg=1, Ciclosporin=1, Eculizumab=1, Prednisolone=1). Causes of death were available in 31/34 patients; infections=18, coronary artery disease=5, malignancy=4, bowel obstruction=1 and respiratory failure=2. Only one patient died from an acute brain stem relapse.

Conclusion

Approximately 1 in 10 AQP4-NMOSD patients died over a 10-year period. The majority of patients had significant disability, suggesting possible association with NMOSD mortality. Infection was the leading cause of death, suggesting a possible relationship with immunosuppression. Striking a balance between disease suppression and mitigation of side effects poses a significant challenge in autoimmune neurological conditions.

emily.gibbons@doctors.org.uk

070 What is seronegative neuromyelitis optica spectrum disorder?

Background

Most but not all cases of Neuromyelitis Optica Spectrum Disorder (NMOSD) are associated with Aquaporin-4 (AQP4) or myelin oligodendrocyte glycoprotein (MOG) antibodies.

Objective

To determine the clinical characteristics of seronegative NMOSD

Method

Retrospective review of seronegative NMOSD in Liverpool and Oxford between January 2010–2020

Results

Of NMOSD=727, 49(7%) were seronegative. The male to female ratio was 1:2.5 and median age at onset was 36(5–57) years. In 2/3 of patients the index presentation was myelitis=22 or myelitis+optic neuritis=11. In 26/33 (79%), longitudinally extensive myelitis was present. Optic neuritis=9 (4 bilateral) and brain involvement=7 were also seen. Relapsing disease was observed in 39/49(80%) of patients. The median annualised attack rate was 0.58 over a median disease duration of 78 (3–258) months. Unmatched CSF oligoclonal bands (CSF-OCBs) were detected in 4/38(11%) and 31/49(63%) fulfilled multiple sclerosis (MS) diagnostic criteria. Immunosuppression (typically Mycophenolate and Rituximab) was used in 34/49(69%). Median last EDSS was 4 (1–10) with death recorded in 5/49 (10%) patients.

Conclusion

Seronegative NMOSD is uncommon. Longitudinal myelitis with/without optic neuritis is a common initial presentation. Similar to AQP4-IgG, NMOSD disability and mortality rates are high. Absence of unmatched CSF-OCB and typical brain lesions help to distinguish this disease from MS.

emily.gibbons@doctors.org.uk

Do we still need OCBs in MS diagnosis and how many?

Background

A standard cut-off of ≥2 CSF-specific OCBs is used in multiple sclerosis but some studies suggest ≥3 CSF OCBs maybe more specific.

Aim

To determine if a cut-off of ≥2 or ≥3 CSF OCBs should be used in MS

Materials and Methods

Oligoclonal bands were tested using standardised methods incorporating iso- electric focussing. Samples sent between July 2018-June 2019 were included. CSF OCB number (1, ≥2,

≥3, or unclear) was assessed by two blinded raters and case records were reviewed.

Results

CSF OCBs were detected in 196/746 (26%) samples (CSF OCB=1; 14/196 (7%), ≥2=182/196 (93%), ≥3=169/196 (86%). Clinical data were available in 157 patients (MS=101, other inflammatory=37, unclear significance=19). Excluding CSF OCB results, 68/101 (67%) cases fulfilled MS diagnostic criteria. Of patients with 1, ≥2 and ≥3 CSF OCBs, 1/8 (12%), 100/182 (55%) and 98/169 (58%) had MS respectively. The positive predictive value of 1, ≥2, and ≥3 OCBs was 0.35, 0.89 and 0.92 respectively in CNS inflammatory disease.

Conclusion

Detection of CSF OCBs was necessary to fulfil MS diagnostic criteria in approximately 30% of cases. Detection of ≥3 OCBs marginally improved the likelihood of an MS diagnosis. Overall measures of sensitivity, specificity and receiver operator curves will be presented.

giovanna.campagna@thewaltoncentre.nhs.uk

069 Co-existent autoimmune disease in AQP4-IgG, MOG-IgG and seronegative NMOSD

Background

Neuromyelitis Optica Spectrum Disorder (NMOSD) is an autoimmune inflammatory disorder of the central nervous system (CNS), and in most cases is associated with Aquaporin-4 antibodies (AQP4- IgG). Severe optic neuritis, longitudinally extensive myelitis and brain involvement is characteristic. Similarly presenting patients may not have detectable AQP4-IgG (seronegative NMOSD) or have Myelin Oligo- dendrocyte Glycoprotein IgG (MOG-IgG).

Method

A retrospective study of AQP4-IgG, MOG-IgG, and seronegative NMOSD patients attending the highly specialised NMOSD service between September 2010-August 2019 was performed. In particular, the presence of coexistent autoimmunity was assessed.

Results

Coexistent autoimmunity in AQP4-IgG patients was higher as compared to MOG-IgG and seron- egative NMOSD (30% vs. 8% vs. 8%). Some AQP4-IgG patients had 2nd and 3rd autoimmune diseases (7% and 1% respectively). In contrast no patients with MOG-IgG or seronegative NMOSD had 2 or more other autoimmune diseases.

Conclusion

Coexistent autoimmunity in AQP4-IgG NMOSD is more common that in seronegative NMOSD and patients with MOG-IgG. It is reasonable to periodically assess for coexistent autoimmunity in AQP4-IgG NMOSD as it is present in almost a third of patients. Finally the detection of ≥2 autoimmune diseases in newly presenting cases provides a useful clue to AQP4-IgG NMOSD whilst antibody results are awaited.

giovanna.campagna@thewaltoncentre.nhs.uk

Health utilities and costs for neuromyelitis optica spectrum disorder

Background

Neuromyelitis optica spectrum disorder (NMOSD) is a rare, neurological disease that places a significant burden on patients, their carers, and healthcare systems.

Objectives

To estimate patient and carer health utilities and costs of NMOSD within the UK setting.

Methods

Patients with NMOSD and their carers, recruited via a regional specialist treatment centre, completed a postal questionnaire that included a resource use measure, the EuroQoL (EQ)-5D-5L, EQ-5D-VAS, Vision and Quality of Life Index (VisQoL), Carer Experience Survey (CES) and the Expanded Disability Status Scale (EDSS). The questionnaire asked about respondents’ use of health and community care services, non-medical costs, informal care and work capacity. Data were analysed descriptively. Uncertainties in costs and utilities were assessed using bootstrap analysis.

Results

117 patients and 74 informal carers responded to the survey. Patients’ mean EQ-5D-5L and VisQoL health utilities (95% central range) were 0.54 (− 0.29, 1.00) and 0.79 (0.11, 0.99), respectively. EQ-5D-5L utility decreased with increasing EDSS score bandings, from 0.80 (0.75, 0.85) for EDSS ≤ 4.0, to 0.20 (− 0.29, 0.56) for EDSS 8.0 to 9.5. Mean, 3-month total costs were £5623 (£2096, £12,156), but ranged from £562 (£381, £812) to £32,717 (£2888, £98,568) for these EDSS bandings. Carer-reported EQ-5D-5L utility and CES index scores were 0.85 (0.82, 0.89) and 57.67 (52.69, 62.66). Mean, 3-month costs of informal care were £13,150 to £24,560.

Conclusions

NMOSD has significant impacts on health utilities and NHS and carer costs. These data can be used as inputs to cost-effectiveness analyses of new medicines for NMOSD.

Association of Maintenance Intravenous Immunoglobulin With Prevention of Relapse in Adult Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease

Importance

Recent studies suggest that maintenance intravenous immunoglobulin (IVIG) may be an effective treatment to prevent relapses in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD); however, most of these studies had pediatric cohorts, and few studies have evaluated IVIG in adult patients.

Objective

To determine the association of maintenance IVIG with the prevention of disease relapse in a large adult cohort of patients with MOGAD.

Design, Setting, and Participants

This was a retrospective cohort study conducted from January 1, 2010, to October 31, 2021. Patients were recruited from 14 hospitals in 9 countries and were included in the analysis if they (1) had a history of 1 or more central nervous system demyelinating attacks consistent with MOGAD, (2) had MOG-IgG seropositivity tested by cell-based assay, and (3) were age 18 years or older when starting IVIG treatment. These patients were retrospectively evaluated for a history of maintenance IVIG treatment.

Exposures

Maintenance IVIG.

Main Outcomes and Measures

Relapse rates while receiving maintenance IVIG compared with before initiation of therapy.

Results

Of the 876 adult patients initially identified with MOGAD, 59 (median [range] age, 36 [18-69] years; 33 women [56%]) were treated with maintenance IVIG. IVIG was initiated as first-line immunotherapy in 15 patients (25%) and as second-line therapy in 37 patients (63%) owing to failure of prior immunotherapy and in 7 patients (12%) owing to intolerance to prior immunotherapy. The median (range) annualized relapse rate before IVIG treatment was 1.4 (0-6.1), compared with a median (range) annualized relapse rate while receiving IVIG of 0 (0-3) (t108 = 7.14; P < .001). Twenty patients (34%) had at least 1 relapse while receiving IVIG with a median (range) time to first relapse of 1 (0.03-4.8) years, and 17 patients (29%) were treated with concomitant maintenance immunotherapy. Only 5 of 29 patients (17%) who received 1 g/kg of IVIG every 4 weeks or more experienced disease relapse compared with 15 of 30 patients (50%) treated with lower or less frequent dosing (hazard ratio, 3.31; 95% CI, 1.19-9.09; P = .02). At final follow-up, 52 patients (88%) were still receiving maintenance IVIG with a median (range) duration of 1.7 (0.5-9.9) years of therapy. Seven of 59 patients (12%) discontinued IVIG therapy: 4 (57%) for inefficacy, 2 (29%) for adverse effects, and 1 (14%) for a trial not receiving therapy after a period of disease inactivity.

Conclusions and Relevance

Results of this retrospective, multicenter, cohort study of adult patients with MOGAD suggest that maintenance IVIG was associated with a reduction in disease relapse. Less frequent and lower dosing of IVIG may be associated with treatment failure. Future prospective randomized clinical trials are warranted to confirm these findings.

Astrocytic outer retinal layer thinning is not a feature in AQP4-IgG seropositive neuromyelitis optica spectrum disorders

BACKGROUND

Patients with anti-aquaporin-4 antibody seropositive (AQP4-IgG+) neuromyelitis optica spectrum disorders (NMOSDs) frequently suffer from optic neuritis (ON) leading to severe retinal neuroaxonal damage. Further, the relationship of this retinal damage to a primary astrocytopathy in NMOSD is uncertain. Primary astrocytopathy has been suggested to cause ON-independent retinal damage and contribute to changes particularly in the outer plexiform layer (OPL) and outer nuclear layer (ONL), as reported in some earlier studies. However, these were limited in their sample size and contradictory as to the localisation. This study assesses outer retinal layer changes using optical coherence tomography (OCT) in a multicentre cross-sectional cohort.

METHOD

197 patients who were AQP4-IgG+ and 32 myelin-oligodendrocyte-glycoprotein antibody seropositive (MOG-IgG+) patients were enrolled in this study along with 75 healthy controls. Participants underwent neurological examination and OCT with central postprocessing conducted at a single site.

RESULTS

No significant thinning of OPL (25.02±2.03 µm) or ONL (61.63±7.04 µm) were observed in patients who were AQP4-IgG+ compared with patients who were MOG-IgG+ with comparable neuroaxonal damage (OPL: 25.10±2.00 µm; ONL: 64.71±7.87 µm) or healthy controls (OPL: 24.58±1.64 µm; ONL: 63.59±5.78 µm). Eyes of patients who were AQP4-IgG+ (19.84±5.09 µm, p=0.027) and MOG-IgG+ (19.82±4.78 µm, p=0.004) with a history of ON showed parafoveal OPL thinning compared with healthy controls (20.99±5.14 µm); this was not observed elsewhere.

CONCLUSION

The results suggest that outer retinal layer loss is not a consistent component of retinal astrocytic damage in AQP4-IgG+ NMOSD. Longitudinal studies are necessary to determine if OPL and ONL are damaged in late disease due to retrograde trans-synaptic axonal degeneration and whether outer retinal dysfunction occurs despite any measurable structural correlates.

Factors Associated With Relapse and Treatment of Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease in the United Kingdom

IMPORTANCE

Longer-term outcomes and risk factors associated with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are not well established.

OBJECTIVE

To investigate longer-term risk of relapse and factors associated with this risk among patients with MOGAD.

DESIGN, SETTING, AND PARTICIPANTS

This large, single-nation, prospective cohort study was conducted among 276 patients with MOGAD at 5 health care centers in the UK. Data from January 1973 to March 2020 were collected from 146 patients at Oxford and its outreach sites, 65 patients at Liverpool, 32 patients at a children's hospital in Birmingham, 22 patients at a children's hospital in London, and 11 patients at Cardiff, Wales. Data were analyzed from April through July 2020.

MAIN OUTCOMES AND MEASURES

Risk of relapse and annualized relapse rate were evaluated according to different baseline features, including onset age, onset phenotype, and incident vs nonincident group, with the incident group defined as patients diagnosed with antibodies against myelin oligodendrocyte glycoprotein before a second attack. Time to next relapse among patients experiencing relapse was measured and compared between the maintenance therapy subgroup and each first-line treatment group. The no-treatment group was defined as the off-treatment phase among patients who were relapsing, which could occur between any attack or between the last attack and last follow-up.

RESULTS

Among 276 patients with MOGAD, 183 patients were identified as being part of the incident group. There were no differences in mean (SD) onset age between total and incident groups (26.4 [17.6] years vs 28.2 [18.1] years), and female patients were predominant in both groups (166 [60.1%] female patients vs 106 [57.9%] female patients). The most common presentation overall was optic neuritis (ON) (119 patients among 275 patients with presentation data [43.3%]), while acute disseminated encephalomyelitis (ADEM), brain, or brainstem onset was predominant among 69 patients aged younger than 12 years (47 patients [68.1%]), including 41 patients with ADEM (59.4%). In the incident group, the 8-year risk of relapse was 36.3% (95% CI, 27.1%-47.5%). ON at onset was associated with increased risk of relapse compared with transverse myelitis at onset (hazard ratio [HR], 2.66; 95% CI, 1.01-6.98; P = .047), but there was no statistically significant difference with adjustment for a follow-on course of corticosteroids. Any TM at onset (ie, alone or in combination with other presentations [ie, ON or ADEM, brain, or brain stem]) was associated with decreased risk of relapse compared with no TM (HR, 0.41; 95% CI, 0.20-0.88; P = .01). Young adult age (ie, ages >18-40 years) was associated with increased risk of relapse compared with older adult age (ie, ages >40 years) (HR, 2.71; 95% CI, 1.18-6.19; P = .02). First-line maintenance therapy was associated with decreased risk of relapse when adjusted for covariates (prednisolone: HR, 0.33; 95% CI, 0.12-0.92; P = .03; prednisolone, nonsteroidal immunosuppressant, or combined: HR, 0.51; 95% CI, 0.28-0.92; P = .03) compared with the no-treatment group.

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that onset age and onset phenotype should be considered when assessing subsequent relapse risk and that among patients experiencing relapse, prednisolone, first-line immunosuppression, or a combination of those treatments may be associated with decreased risk of future relapse by approximately 2-fold. These results may contribute to individualized treatment decisions.

Early predictors of disability of paediatric-onset AQP4-IgG-seropositive neuromyelitis optica spectrum disorders

OBJECTIVE

To describe onset clinical features predicting time to first relapse and time to long-term visual, motor and cognitive disabilities in paediatric-onset aquaporin-4 antibody (AQP4-IgG) neuromyelitis optica spectrum disorders (NMOSDs).

METHODS

In this retrospective UK multicentre cohort study, we recorded clinical data of paediatric-onset AQP4-IgG NMOSD. Univariate and exploratory multivariable Cox proportional hazard models were used to identify long-term predictors of permanent visual disability, Expanded Disability Status Scale (EDSS) score of 4 and cognitive impairment.

RESULTS

We included 49 paediatric-onset AQP4-IgG patients (38.8% white, 34.7% black, 20.4% Asians and 6.1% mixed), mean onset age of 12±4.1 years, and 87.7% were female. Multifocal onset presentation occurred in 26.5% of patients, and optic nerve (47%), area postrema/brainstem (48.9%) and encephalon (28.6%) were the most involved areas. Overall, 52.3% of children had their first relapse within 1 year from disease onset. Children with onset age <12 years were more likely to have an earlier first relapse (p=0.030), despite showing no difference in time to immunosuppression compared with those aged 12-18 years at onset. At the cohort median disease duration of 79 months, 34.3% had developed permanent visual disability, 20.7% EDSS score 4 and 25.8% cognitive impairment. Visual disability was associated with white race (p=0.032) and optic neuritis presentations (p=0.002). Cognitive impairment was predicted by cerebral syndrome presentations (p=0.048), particularly if resistant to steroids (p=0.034).

CONCLUSIONS

Age at onset, race, onset symptoms and resistance to acute therapy at onset attack predict first relapse and long-term disabilities. The recognition of these predictors may help to power future paediatric clinical trials and to direct early therapeutic decisions in AQP4-IgG NMOSD.

Treatment of myelin oligodendrocyte glycoprotein antibody associated disease with subcutaneous immune globulin

Myelin oligodendrocyte glycoprotein (MOG)-antibody associated disease (MOGAD) is a distinct demyelinating disease of the central nervous system that often exhibits a relapsing course. Immune globulin (Ig) therapy has been proposed as maintenance therapy to prevent relapses in MOGAD, but existing reports are limited to the use of intravenous Ig (IVIG). Subcutaneous Ig (SCIG) may exhibit several advantages over IVIG, including self-administration and less systemic adverse effects. Herein, we report six patients with MOGAD who were treated with subcutaneous Ig (SCIG) with good tolerability and without any relapses during follow-up. This supports the rationale for prospective randomized studies of SCIG in MOGAD.

Images of the month 1: Trident sign and neurosarcoidosis

A 36-year-old woman presented with a subacute, relapsing myelitis, manifesting as bilateral ascending lower limb paraesthesia, partially responsive to steroids. Imaging demonstrated a longitudinal spinal cord lesion, with a unique and characteristic sign (the 'trident sign') on axial views, which is specific to a diagnosis of neurosarcoidosis. This case highlights the importance of using this feature to distinguish a longitudinal cord lesion of sarcoidosis from other differentials.

Predictors of relapse in MOG antibody associated disease: a cohort study

OBJECTIVE

To identify factors predictive of relapse risk and disability in myelin oligodendrocyte glycoprotein associated disease (MOGAD).

SETTING

Patients were seen by the neuromyelitis optica spectrum disorders (NMOSD) service in Liverpool, UK, a national referral centre for adult patients with MOGAD, NMOSD and related conditions.

PARTICIPANTS

Patients with MOGAD=76 from England, Northern Ireland and Scotland were included in this cohort study.

RESULTS

Relapsing disease was observed in 55% (42/76) of cases. Steroid treatment >1 month (OR 0.2, 95% CI 0.05 to 0.80; p=0.022), transverse myelitis (TM) at first attack (OR 0.03, 95% CI 0.004 to 0.23; p=0.001) and male sex (OR 0.16, 95% CI 0.04 to 0.68; p=0.014) were associated with monophasic disease (area under the curve=0.85). Male sex (HR 0.46, 95% CI 0.24 to 0.89; p=0.011) and TM at disease onset (HR 0.42, 95% CI 0.22 to 0.82; p=0.011) were also associated with an increased latency to first relapse. 45% (32/71) of patients became MOG-antibody negative and in relapsing patients negative seroconversion was associated with a lower relapse risk (relative risk 0.11 95% CI 0.05 to 0.26; p<0.001). No specific factors were predictive of visual or overall disability.

CONCLUSIONS

Male patients with spinal cord involvement at disease onset have a lower risk of relapsing disease and longer latency to first relapse. Steroid treatment for at least 1 month at first attack was also associated with a monophasic disease course. MOG-antibody negative seroconversion was associated with a lower risk of relapse and may help inform treatment decisions and duration.

Retinal Optical Coherence Tomography in Neuromyelitis Optica

Background and Objectives

To determine optic nerve and retinal damage in aquaporin-4 antibody (AQP4-IgG)-seropositive neuromyelitis optica spectrum disorders (NMOSD) in a large international cohort after previous studies have been limited by small and heterogeneous cohorts.

Methods

The cross-sectional Collaborative Retrospective Study on retinal optical coherence tomography (OCT) in neuromyelitis optica collected retrospective data from 22 centers. Of 653 screened participants, we included 283 AQP4-IgG–seropositive patients with NMOSD and 72 healthy controls (HCs). Participants underwent OCT with central reading including quality control and intraretinal segmentation. The primary outcome was thickness of combined ganglion cell and inner plexiform (GCIP) layer; secondary outcomes were thickness of peripapillary retinal nerve fiber layer (pRNFL) and visual acuity (VA).

Results

Eyes with ON (NMOSD-ON, N = 260) or without ON (NMOSD-NON, N = 241) were assessed compared with HCs (N = 136). In NMOSD-ON, GCIP layer (57.4 ± 12.2 μm) was reduced compared with HC (GCIP layer: 81.4 ± 5.7 μm, p < 0.001). GCIP layer loss (−22.7 μm) after the first ON was higher than after the next (−3.5 μm) and subsequent episodes. pRNFL observations were similar. NMOSD-NON exhibited reduced GCIP layer but not pRNFL compared with HC. VA was greatly reduced in NMOSD-ON compared with HC eyes, but did not differ between NMOSD-NON and HC.

Discussion

Our results emphasize that attack prevention is key to avoid severe neuroaxonal damage and vision loss caused by ON in NMOSD. Therapies ameliorating attack-related damage, especially during a first attack, are an unmet clinical need. Mild signs of neuroaxonal changes without apparent vision loss in ON-unaffected eyes might be solely due to contralateral ON attacks and do not suggest clinically relevant progression but need further investigation.

No strong HLA association with MOG antibody disease in the UK population

Improvements in assays for detecting serum antibodies against myelin oligodendrocyte glycoprotein (MOG) have led to the appreciation of MOG‐antibody‐associated disease (MOGAD) as a novel disorder. However, much remains unknown about its etiology. We performed human leukocyte antigen (HLA) analysis in 82 MOGAD patients of European ancestry in the UK population. No HLA class II associations were observed, thus questioning the mechanism of anti‐MOG antibody generation. A weak protective association of HLA‐C*03:04 was observed (OR = 0.26, 95% CI = 0.10‐0.71, p_c = 0.013), suggesting a need for continued efforts to better understand MOGAD genetics and pathophysiology.

Case Report: Myelin Oligodendrocyte Glycoprotein Antibody-Associated Relapse With COVID-19

A 39-year-old lady with relapsing myelin oligodendrocyte glycoprotein antibody (MOG-IgG) associated disease developed coryzal symptoms, malaise, sweating, and postural dizziness. Six days later she presented with painful progressive right visual loss consistent with optic neuritis. COVID-19 was confirmed by nasopharyngeal swab and MOG-IgG serological reversion was noted. Visual function improved following steroids and plasma exchange. This case highlights a possible causal association between inflammation due to COVID-19 and a relapse of MOG-IgG associated disease. It also highlights the clinical relevance of reporting MOG-IgG titers in MOG-IgG associated disease.

Cohort profile: a collaborative multicentre study of retinal optical coherence tomography in 539 patients with neuromyelitis optica spectrum disorders (CROCTINO)

PURPOSE

Optical coherence tomography (OCT) captures retinal damage in neuromyelitis optica spectrum disorders (NMOSD). Previous studies investigating OCT in NMOSD have been limited by the rareness and heterogeneity of the disease. The goal of this study was to establish an image repository platform, which will facilitate neuroimaging studies in NMOSD. Here we summarise the profile of the Collaborative OCT in NMOSD repository as the initial effort in establishing this platform. This repository should prove invaluable for studies using OCT to investigate NMOSD.

PARTICIPANTS

The current cohort includes data from 539 patients with NMOSD and 114 healthy controls. These were collected at 22 participating centres from North and South America, Asia and Europe. The dataset consists of demographic details, diagnosis, antibody status, clinical disability, visual function, history of optic neuritis and other NMOSD defining attacks, and OCT source data from three different OCT devices.

FINDINGS TO DATE

The cohort informs similar demographic and clinical characteristics as those of previously published NMOSD cohorts. The image repository platform and centre network continue to be available for future prospective neuroimaging studies in NMOSD. For the conduct of the study, we have refined OCT image quality criteria and developed a cross-device intraretinal segmentation pipeline.

FUTURE PLANS

We are pursuing several scientific projects based on the repository, such as analysing retinal layer thickness measurements, in this cohort in an attempt to identify differences between distinct disease phenotypes, demographics and ethnicities. The dataset will be available for further projects to interested, qualified parties, such as those using specialised image analysis or artificial intelligence applications.

Treatment of MOG-IgG-associated disorder with rituximab: An international study of 121 patients

OBJECTIVE

To assess the effect of anti-CD20 B-cell depletion with rituximab (RTX) on relapse rates in myelin oligodendrocyte glycoprotein antibody-associated disorder (MOGAD).

METHODS

Retrospective review of RTX-treated MOGAD patients from 29 centres in 13 countries. The primary outcome measure was change in relapse rate after starting rituximab (Poisson regression model).

RESULTS

Data on 121 patients were analysed, including 30 (24.8%) children. Twenty/121 (16.5%) were treated after one attack, of whom 14/20 (70.0%) remained relapse-free after median (IQR) 11.2 (6.3-14.1) months. The remainder (101/121, 83.5%) were treated after two or more attacks, of whom 53/101 (52.5%) remained relapse-free after median 12.1 (6.3-24.9) months. In this 'relapsing group', relapse rate declined by 37% (95%CI=19-52%, p<0.001) overall, 63% (95%CI=35-79%, p = 0.001) when RTX was used first line (n = 47), and 26% (95%CI=2-44%, p = 0.038) when used after other steroid-sparing immunotherapies (n = 54). Predicted 1-year and 2-year relapse-free survival was 79% and 55% for first-line RTX therapy, and 38% and 18% for second-/third-line therapy. Circulating CD19+B-cells were suppressed to <1% of total circulating lymphocyte population at the time of 45/57 (78.9%) relapses.

CONCLUSION

RTX reduced relapse rates in MOGAD. However, many patients continued to relapse despite apparent B-cell depletion. Prospective controlled studies are needed to validate these results.

Steroid refractory giant cell arteritis with bilateral vertebral artery occlusion and middle cerebellar peduncle infarction

Giant cell arteritis is the most common primary systemic vasculitis in adults aged ≥50 years and peaks in the eighth decade of life. Common symptoms include headache, scalp tenderness and jaw claudication. Elevated acute phase reactants (erythrocyte sedimentation rate and C-reactive protein) are present in >90% of patients. Visual loss is a well-recognised complication, but approximately 2-4% of giant cell arteritis patients experience stroke, most frequently in the vertebrobasilar territory. We describe a 72-year-old male who developed bilateral vertebral artery occlusion and middle cerebellar peduncle infarction secondary to giant cell arteritis in spite of high-dose steroids.

Characteristics, immobilization, and application of Candida rugosa lipase: a review

Candida rugosa lipase (CRL) is one of the lipases widely used in various food industries and studies, especially in linkage with the modification of lipids. This review discusses CRL, including CRL features (molecular biology, the structure of the enzyme protein, the flap/ lid), catalytic mechanisms and substrates specificity, CRL immobilization technologies, and various applications in lipid modifications. CRL has five isoenzymes, namely LIP1 - LIP5, then develops again into LIP1 - LIP8. However, LIP1 is the most commonly found isoenzymes. CRL has a structure similar to that of Geotricum candidum lipase, has a flap/ lid, which is an active side cover in the form of α-helix, which is relatively shorter than other lipases. The active site of the CRL consists of triads ser-209, His-449, and Glu-341, while the catalytic mechanism of the CRL is the same as the other lipases by the nucleophilic attack. CRL catalyzes triacylglycerol at all positions randomly and has hydrolysis and synthesis activities that are strongly affected by the presence of water in the reaction system. CRL can be used for various lipid modifications through hydrolysis, esterification, interesterification/transesterification, and alcoholysis/ glycerolysis reactions.

SHP2 inhibitor protects AChRs from effects of myasthenia gravis MuSK antibody

Objective

To determine whether an SRC homology 2 domain-containing phosphotyrosine phosphatase 2 (SHP2) inhibitor would increase muscle-specific kinase (MuSK) phosphorylation and override the inhibitory effect of MuSK-antibodies (Abs).

Methods

The effect of the SHP2 inhibitor NSC-87877 on MuSK phosphorylation and AChR clustering was tested in C2C12 myotubes with 31 MuSK-myasthenia gravis (MG) sera and purified MuSK-MG IgG4 preparations.

Results

In the absence of MuSK-MG Abs, NSC-87877 increased MuSK phosphorylation and the number of AChR clusters in C2C12 myotubes in vitro and in DOK7-overexpressing C2C12 myotubes that form spontaneous AChR clusters. In the presence of MuSK-MG sera, the AChR clusters were reduced, as expected, but NSC-87877 was able to protect or restore the clusters. Two purified MuSK-MG IgG4 preparations inhibited both MuSK phosphorylation and AChR cluster formation, and in both, clusters were restored with NSC-87877.

Conclusions

Stimulating the agrin-LRP4-MuSK-DOK7 AChR clustering pathway with NSC-87877, or other drugs, could represent a novel therapeutic approach for MuSK-MG and could potentially improve other NMJ disorders with reduced AChR numbers or disrupted NMJs.

Role of complement and potential of complement inhibitors in myasthenia gravis and neuromyelitis optica spectrum disorders: a brief review

The complement system is a powerful member of the innate immune system. It is highly adept at protecting against pathogens, but exists in a delicate balance between its protective functions and overactivity, which can result in autoimmune disease. A cascade of complement proteins that requires sequential activation, and numerous complement regulators, exists to regulate a proportionate response to pathogens. In spite of these mechanisms there is significant evidence for involvement of the complement system in driving the pathogenesis of variety of diseases including neuromyelitis optica spectrum disorders (NMOSD) and myasthenia gravis (MG). As an amplification cascade, there are an abundance of molecular targets that could be utilized for therapeutic intervention. Clinical trials assessing complement pathway inhibition in both these conditions have recently been completed and include the first randomized placebo-controlled trial in NMOSD showing positive results. This review aims to review and update the reader on the complement system and the evolution of complement-based therapeutics in these two disorders.

Neuromyelitis optica spectrum disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an uncommon antibody-mediated disease of the central nervous system. Long segments of spinal cord inflammation (myelitis), severe optic neuritis, and/or bouts of intractable vomiting and hiccoughs (area postrema syndrome) are classic presentations of the disease and may alert the clinician to the diagnosis. Untreated, approximately 50% of NMOSD patients will be wheelchair users and blind, and a third will have died within 5 years of their first attack. Unlike multiple sclerosis, a progressive clinical course is very unusual and the accrual of disability is related to relapses. Approximately 75% of patients have antibodies against aquaporin-4, a water channel expressed on astrocytes. Relapses are treated aggressively to prevent residual disability with high-dose steroids and often plasma exchange. Relapse prevention is crucial and achieved with long-term immunosuppression. In this article we review the pathogenesis, clinical features, diagnosis and management of NMOSD.

Nitrous oxide myelopathy with functional vitamin B 12 deficiency

Recreational use of nitrous oxide as a 'legal high' is increasing in the UK. Physicians should be 'street wise' to this increasing prevalence and aware of the potential neurological complications which may result from misuse. We describe a 17-year-old male patient who presented to neurology with a severe myelopathy following prolonged recreational use of nitrous oxide. MRI demonstrated characteristic changes affecting the dorsal columns and blood tests demonstrated a 'functional' B₁₂ deficiency. Clinical and radiological improvement was noted following initiation of vitamin B₁₂ replacement.

Rituximab in neurological disease: principles, evidence and practice

Rituximab is a widely used B-cell-depleting monoclonal antibody. It is unlicensed for use in neurological disorders and there are no treatment guidelines. However, as a rapidly acting, targeted therapy with growing evidence of efficacy and tolerability in several neuroinflammatory disorders, it is an attractive alternative to conventional immunomodulatory medications. This practical review aims to explain the basic principles of B-cell depletion with therapeutic monoclonal antibodies. We present the evidence for using rituximab in neurological diseases, and describe the practical aspects of prescribing, including dosing, monitoring, safety, treatment failure and its use in special circumstances such as coexisting viral hepatitis, pregnancy and lactation. We provide an administration guide, checklist and patient information leaflet, which can be adapted for local use. Finally, we review the safety data of rituximab and ocrelizumab (a newer and recently licensed B-cell-depleting therapy for multiple sclerosis) and suggest monitoring and risk reduction strategies.

Intracranial dural arteriovenous fistula mistaken as cervical transverse myelitis

We describe a man with an intracranial dural arteriovenous fistula that presented as a subacute longitudinally extensive cervical myelopathy. The uncommon location of the fistula and the absence of specific radiological signs resulted in initial misdiagnosis as longitudinally extensive transverse myelitis. Neurologists should have a high index of suspicion for dural arteriovenous fistula in older men, especially those with subacute or chronic symptoms, acellular cerebrospinal fluid and, particularly, if there is neurological deterioration soon after corticosteroid treatment. Patients need early angiography to identify this treatable cause of myelopathy.

Autoimmune encephalitis (NMDAR antibody) in a patient receiving chronic post-transplant immunosuppression

Autoimmune encephalitis associated with antibodies (Abs) directed against the synaptic ligand-gated ion channel NMDA receptor (NMDAR) was first described as a paraneoplastic disorder in association with ovarian teratoma. Other forms of neoplasia have subsequently been reported although many patients do not have a tumour. Tumour removal, where applicable, and immunotherapy form the mainstays of treatment. We present a patient who developed NMDAR-Ab encephalitis despite being chronically immunosuppressed following organ transplantation, and who was eventually found to have an occult malignancy in the form of non-Hodgkin's lymphoma.