Evaluation of efficacy and tolerability of first-line therapies in NMOSD

Potential drug targets for Neuromyelitis optica spectrum disorders (NMOSD): A Mendelian randomization analysis

BACKGROUND

Certain peripheral proteins are involved in the development of Neuromyelitis optica spectrum disorders (NMOSD), such as IL-6, complement proteins, and MHC class II molecules. However, the roles of other new protein biomarkers are unclear. Current NMOSD treatments (e.g., intravenous pulse methylprednisolone, or satralizumab for IL-6 receptor inhibition) can only manage symptoms, necessitating the identification of new drug targets to treat NMOSD. The objective of this study is to identify potential drug targets for NMOSD through Mendelian randomization (MR) analysis, thereby addressing the limitations of current treatments and providing better clinical options for patients.

METHODS

NMOSD potential drug targets were evaluated via MR. Data was obtained from a genome-wide association study (GWAS) with 132 individuals with AQP4-IgG-positive NMOSD and 1244 controls. Genetic instruments for plasma and cerebrospinal fluid (CSF) proteins were identified. Sensitivity analyses were conducted using Bayesian co-localization, reverse causality testing and phenotype scanning. Additionally, a comparison and analysis of protein-protein interactions (PPI) were conducted to identify potential causal proteins. The implications of these findings were further explored by evaluating existing NMOSD drugs and their respective targets.

RESULTS

Four proteins were identified at the FDR correction via MR analysis (p < 0.05). Higher levels of PF4V1 (OR = 0.47; 95% CI, 0.29-0.78; p = 3.39 × 10-3) and FAM3B (OR = 0.12; 95% CI, 0.03-0.45; p = 1.65 × 10-3) were associated with a reduced risk of NMOSD, whereas elevated SERPINA1 (OR = 2.28; 95% CI, 1.29-4.04; p= 4.71 × 10-3) and CLEC11A (OR = 13.45; 95% CI, 1.29-4.04; p = 4.71 × 10-3) were related to an increased risk of NMOSD. Bayesian co-localization showed that the protein-related genes shared the same mutation as NMOSD (all PPH4>0.80). Reverse causality testing showed no evidence of NMOSD-driven protein changes (all p > 0.05). PPI analysis revealed SERPINA1 interacts with PF4V1 (combined score = 0.72). Drug evaluation identified Mercaptoethanol and Ferrous gluconate as repurposing candidates.

CONCLUSION

Increased levels of plasma CLEC11A and SERPINA1 are correlated with an elevated risk of NMOSD, whereas elevated levels of plasma PF4V1 and CSF FAM3B are associated with a decreased risk of NMOSD. The opposing effects of risk or protective proteins suggest synergistic targeting could improve efficacy beyond current immunosuppressive regimens. Nonetheless, clinical trials are required to confirm the findings.

Neuromyelitis optica spectrum disorder in Latin America: a global data share initiative

The objective of the study was to develop a global data share initiative to collect data from many sources (registries and observational databases) of NMOSD (neuromyelitis optica spectrum disorder) patients in LATAM (Latin America) to describe the frequency of patients untreated in our region to focus access and educational projects to improve patients care and long-term outcomes. METHODS: This was a non-interventional, multicenter cross-sectional study that included NMOSD patients from LATAM. Data were acquired through independent registries and observational single and multicenter cohorts from 16 countries (Argentina n = 379, Brazil n = 250, Chile n = 50, Colombia n = 250, Ecuador n = 47, Mexico n = 101, Uruguay n = 10, Venezuela n = 31, Aruba n = 4, Cuba n = 13, El Salvador n = 7, Guatemala n = 23, Honduras n = 7, Nicaragua n = 6, Panama n = 42 and Dominican Republic n = 48). Data homogenization was conducted using the data dictionary provided by each custodian in a single, centralized database with variables loaded in a homogeneous manner. RESULTS: A total of 1264 patients were included from three nationwide registries and seven observational cohorts from LATAM. 90.8 % (n = 1148) patients were receiving long-term treatment for NMOSD, while 9.2 % (n = 116) were untreated. Most frequent treatment received in the analyzed population was rituximab (56.7 %), followed by azathioprine (28 %). Despite the availability of novel therapeutic options such as satralizumab, eculizumab, and inebilizumab, these were used in <5 % of AQP4-IgG-positive patients CONCLUSION: The study helps to understand how patients are being treated in the region and to develop educational and access strategies to improve patients care.

Advances in the treatment of neuromyelitis optic spectrum disorder

Neuromyelitis optic spectrum disorder (NMOSD) is a rare autoimmune disease characterized by recurrent episodes and severe debilitation. It primarily involves the central nervous system and is associated with the presence of aquaporin-4 antibodies. Effective management of NMOSD necessitates long-term therapeutic strategies that focus on alleviating symptoms during acute episodes and preventing relapse. In recent years, the approval of emerging biologics targeting B cells, interleukin-6 receptors, and the complement pathway has marked a transformative development in NMOSD treatment. This article provides a comprehensive review of therapeutic advances in NMOSD, integrating the current literature to serve as a theoretical basis for clinical decision-making of NMOSD patients.

Comparison of treatment efficacy and cost-effectiveness of rituximab and oral agents among patients with neuromyelitis optica spectrum disorders: a population-based cohort study

Background

Rituximab (RTX) is a well-known effective treatment for neuromyelitis optica spectrum disorder (NMOSD).

Aims

To investigate the effectiveness of RTX treatment in patients with NMOSD and compared medical expenses between RTX and other oral agents.

Methods

Using data from the National Health Insurance System database (2010-2021), we compared the time to the first relapse and medical expenses after each medication between groups with RTX and oral agents. Also, we analyzed the association between the level of disability and the type of drugs.

Results

A total of 899 patients were included, and they were divided into two groups according to the type of treatment. The group treated with RTX had a lower risk of relapse than those treated with other oral agents (hazard ratio, 0.479, p < 0.001). Regarding medical expenses, the increase in total medical costs was associated with the use of RTX and the number of relapses. The increase in medical costs was higher in cases with increased disability owing to NMOSD after adjustment for the number of relapses.

Conclusion

In comparison to other oral agents, RTX showed a favorable treatment effect. It is also relatively cost-effective, considering the change in disability in a large-scale real-world nationwide study.

Rituximab maintenance treatment outcomes in patients with relapsing neuromyelitis optica spectrum disorder: a monocentric retrospective analysis

Some patients with neuromyelitis optica spectrum disorder (NMOSD) experience relapse after rituximab (RTX) treatment. In this retrospective study, we analyzed the recurrence-related clinical features, laboratory investigation results, and dosing protocol of 30 female patients with relapsing NMOSD with immunoglobulin G autoantibodies against aquaporin-4 and relapses during repeated 0.5 g RTX infusions as maintenance treatment. The median follow-up period was 6.62 years. Thirty-five episodes were observed, with myelitis being the most frequent. The median expanded disability status scale change score was 0.50. The recurrence rate decreased by 44.23%/year with RTX infusion. Approximately 85.71% of the patients showed relapse without RTX infusion within 10 months. Overall, RTX may be effective for relapsing NMOSD cases.

Immunosuppressive therapy in elderly patients with neuromyelitis optica spectrum disorder: a retrospective multicentre study

BACKGROUND

The risk-benefit relationship of immunosuppressive therapies (ISTs) for elderly patients with neuromyelitis optica spectrum disorder (NMOSD) is not well established. This study aimed to investigate the safety and efficacy of IST in elderly patients with NMOSD.

METHODS

This retrospective study analysed IST efficacy and safety in 101 patients with aquaporin-4 antibody-positive NMOSD aged over 65 years, treated for at least 6 months at five Korean referral centres, focusing on relapse rates, infection events and discontinuation due to adverse outcomes.

RESULTS

The mean age at disease onset was 59.8 years, and female-to-male ratio was 4:1. Concomitant comorbidities at NMOSD diagnosis were found in 87 patients (86%). The median Expanded Disability Status Scale score at the initiation of IST was 3.5. The administered ISTs included azathioprine (n=61, 60%), mycophenolate mofetil (MMF) (n=48, 48%) and rituximab (n=41, 41%). Over a median of 5.8 years of IST, 58% of patients were relapse-free. The median annualised relapse rate decreased from 0.76 to 0 (p<0.001), and 81% experienced improved or stabilised disability. Patients treated with rituximab had a higher relapse-free rate than those treated with azathioprine or MMF (p=0.022). During IST, 21 patients experienced 25 severe infection events (SIEs) over the age of 65 years, and 3 died from pneumonia. 14 patients (14%) experienced 17 adverse events that led to switching or discontinuation of IST. When comparing the incidence rates of SIEs and adverse events, no differences were observed among patients receiving azathioprine, MMF and rituximab.

CONCLUSION

In elderly patients with NMOSD, IST offers potential benefits in reducing relapse rates alongside a tolerable risk of adverse events.

Traditional first-line treatment failure rates in neuromyelitis optica spectrum disorder patients included in the Argentinean registry (RelevarEM)

BACKGROUND

Immunosuppressive therapies as azathioprine (AZA), mycophenolate mofetil (MMF) and rituximab (RTX) are widely prescribed as first-line treatment to prevent relapses in NMOSD. However, the rate of response to these traditional therapies is unknown in Argentina. We aimed to describe and compare treatment failure rates in NMOSD patients included in the Argentinean MS and NMOSD registry (RelevarEM, NCT03375177).

METHODS

A retrospective cohort study was conducted in NMOSD patients included in RelevarEM (a nationwide, longitudinal, observational, non-mandatory registry of MS and NMOSD in Argentina). NMOSD patients were defined based on validate diagnostic criteria. Only NMOSD patients who received AZA or MMF for at least 6 months or RTX for at least 1 month were included. Patients who were receiving AZA, MMF, or RTX and then switched to another 1 of these 3 therapies were included if the above-mentioned criteria for each drug were fulfilled. Data on patient demographics, clinical, neuroradiological findings, and treatments administered were collected. Treatment failure was defined as any new attack/relapse that occurred despite immunosuppressive treatment.

RESULTS

We included 139 NMOSD patients who were receiving AZA (n = 105), MMF (n = 5) or RTX (n = 29) with a mean follow-up time of 41.3 ± 11.4 months and median of EDSS at treatment initiation of 3. We observed a reduction in the annualized relapse rate from pre-treatment to post-treatment of 51.1 %, 48.4 %, and 79.1 % respectively with a Hazard Risk relative to RTX (95 % CI) of 1.67 (1.34-3.54, p = 0.01) for AZA and 2.01 (1.86-4.43, p = 0.008) for MMF. AZA, MMF and RTX failure was observed in 45/105 (42.8 %), 2/5 (40 %) and 3/29 (10.3 %) patients, respectively.

CONCLUSIONS

Treatment failure rates were higher for AZA and MMF than RTX in Argentinean NMOSD patients in a real-world setting. High-efficacy treatment increases the opportunity to prevent attacks of NMOSD.

Mechanisms of gastrointestinal toxicity in neuromyelitis optica spectrum disorder patients treated with mycophenolate mofetil: insights from a mouse model and human study

Mycophenolate mofetil (MMF) is commonly utilized for the treatment of neuromyelitis optica spectrum disorders (NMOSD). However, a subset of patients experience significant gastrointestinal (GI) adverse effects following MMF administration. The present study aims to elucidate the underlying mechanisms of MMF-induced GI toxicity in NMOSD. Utilizing a vancomycin-treated mouse model, we compiled a comprehensive data set to investigate the microbiome and metabolome in the GI tract to elucidate the mechanisms of MMF GI toxicity. Furthermore, we enrolled 17 female NMOSD patients receiving MMF, who were stratified into non-diarrhea NMOSD and diarrhea NMOSD (DNM) groups, in addition to 12 healthy controls. The gut microbiota of stool samples was analyzed using 16S rRNA gene sequencing. Vancomycin administration prevented weight loss and tissue injury caused by MMF, affecting colon metabolomes and microbiomes. Bacterial β-glucuronidase from Bacteroidetes and Firmicutes was linked to intestinal tissue damage. The DNM group showed higher alpha diversity and increased levels of Firmicutes and Proteobacteria. The β-glucuronidase produced by Firmicutes may be important in causing gastrointestinal side effects from MMF in NMOSD treatment, providing useful information for future research on MMF.

IMPORTANCE

Neuromyelitis optica spectrum disorder (NMOSD) patients frequently endure severe consequences like paralysis and blindness. Mycophenolate mofetil (MMF) effectively addresses these issues, but its usage is hindered by gastrointestinal (GI) complications. Through uncovering the intricate interplay among MMF, gut microbiota, and metabolic pathways, this study identifies specific gut bacteria responsible for metabolizing MMF into a potentially harmful form, thus contributing to GI side effects. These findings not only deepen our comprehension of MMF toxicity but also propose potential strategies, such as inhibiting these bacteria, to mitigate these adverse effects. This insight holds broader implications for minimizing complications in NMOSD patients undergoing MMF therapy.

Efficacy and safety of mycophenolate mofetil for steroid reduction in neuromyelitis optica spectrum disorder: a prospective cohort study

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune inflammatory disease that can affect multiple generations and cause complications with long-term prednisolone treatment. This study aimed to evaluate the efficacy and safety of mycophenolate mofetil (MMF) in preventing NMOSD relapse while reducing prednisolone dosage. The trial involved nine patients with NMOSD who received MMF along with prednisolone dose reduction. MMF was effective in achieving prednisolone dose reduction without relapse in 77.8% of patients, with a significant decrease in mean annualized relapse rate. All adverse events were mild. The findings suggest that MMF could be a viable treatment option for middle-aged and older patients who require steroid reduction.Clinical trial registration number: jRCT, jRCTs051180080. Registered February 27th, 2019-retrospectively registered, https://jrct.niph.go.jp/en-latest-detail/jRCTs051180080.

Dental Adverse Effects of Anti-CD20 Therapies

INTRODUCTION

Over the past few years, anti-CD20 therapies like rituximab, ocrelizumab or ofatumumab have seen an increase in interest in the treatment of neurological autoimmune disorders such as multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), or resistant forms of generalized myasthenia gravis (MG). They are generally well-tolerated, but recent reports have highlighted severe dental disorders in patients undergoing anti-CD20 therapies. The aim was to describe a series of cases and to compare with the available scientific literature.

METHODS

We reviewed 6 patient cases with dental disorders during anti-CD20 therapy that were reported to the pharmacovigilance center. A disproportionality analysis was also conducted on Vigibase® for each anti-CD20 and each adverse effect described in the cases.

RESULTS

Six cases of dental and gingival conditions in relatively young patients were reported (median age: 40.5 years old [min: 34; max: 79]). Oral conditions were developed in four patients with MS treated with ocrelizumab and in two patients receiving rituximab (one patient with MG and one with NMOSD). The onset of oral conditions ranged from 10 days to 2 years after treatment initiation. Notably, all patients treated with ocrelizumab experienced gingival recession. Various dental pathologies were observed, including tooth loss, dental pain, caries, brittle teeth, dental fractures, dental abscesses, and periodontitis. Analysis of Vigibase® revealed 284 worldwide cases of dental and gingival conditions under ocrelizumab, 386 cases under rituximab, and 80 under ofatumumab. Significant associations were found between these therapies and dental pathologies, particularly tooth abscesses and infections.

CONCLUSION

To our knowledge, this is the first case series reporting dental conditions developed in patients long-term treated with anti-CD20 treatments. This issue, literature data, and Vigilyze® analysis might be considered a safety signal that necessitates being confirmed with more robust data, such as a retrospective study with a control group. Meanwhile, proactive measures are essential like frequent dental checkups and dental hygienic measures to prevent oral health problems associated with anti-CD20 therapies.

Role of C5 inhibitors in neuromyelitis optica spectrum disorders with seropositive anti-aquaporin-4 antibody: A systematic review and meta-analysis

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disorder characterized by relapses of inflammation and demyelination primarily affecting the optic nerve and the spinal cord. C5 complement inhibition is an effective therapeutic approach in the treatment of NMOSD. In this systematic review and meta-analysis, we aimed to determine the role of C5 inhibitors in the treatment of patients with seropositive anti-aquaporin-4 antibody (AQP4+IgG) NMOSD.

METHODS

This systematic review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Relevant articles were systematically searched through Medline, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science databases until October 6th, 2023. We included randomized clinical trials (RCTs) that investigated the treatment with C5 inhibitors compared to placebo in patients with seropositive NMOSD. The primary endpoint was the rates of first adjudicated relapse. Secondary endpoints included different disability and quality of life measures. The random-effects model was used for all statistical analyses.

RESULTS

Two RCTs with a total of 201 patients were included. C5 inhibitors demonstrated significant reduction of first adjudicated relapse (risk ratio (RR) = 0.05, 95 % CI 0.01-0.15) and Hauser Ambulation Index (HAI) (mean difference (MD): -0.79, 95 % CI -1.27 to -0.31). There was no significant difference between the two groups in Expanded Disability Status Scale (EDSS) (MD -0.23, 95 % CI -0.54-0.08). C5 inhibitors significantly improved the mean change in EQ-5D index (MD 0.08, 95 % CI 0.01-0.14; P = 0.02); however, no significant difference was shown in the mean change in EQ-5D VAS (MD 3.79, 95 % CI -1.61 to 9.19; P = 0.17). Safety measures were comparable between C5 inhibitors and placebo.

CONCLUSION

NMOSD Patients with AQP4+IgG receiving C5 inhibitors have lower rate of relapses and improved levels of disability and quality of life. Real-world studies are warranted to establish the long-term safety of C5 inhibitors.

Targeted inhibition of gut bacterial β-glucuronidases by octyl gallate alleviates mycophenolate mofetil-induced gastrointestinal toxicity

Mycophenolate mofetil (MMF) is a viable therapeutic option against various immune disorders as a chemotherapeutic agent. Nevertheless, its application has been undermined by the gastrotoxic metabolites (mycophenolic acid glucuronide, MPAG) produced by microbiome-associated β-glucuronidase (βGUS). Therefore, controlling microbiota-produced βGUS underlines the potential strategy to improve MMF efficacy by overcoming the dosage limitation. In this study, the octyl gallate (OG) was identified with promising inhibitory activity on hydrolysis of PNPG in our high throughput screening based on a chemical collection of approximately 2000 natural products. Furthermore, OG was also found to inhibit a broad spectrum of BGUSs, including mini-Loop1, Loop 2, mini-Loop 2, and mini-Loop1,2. The further in vivo experiments demonstrated that administration of 20 mg/kg OG resulted in predominant reduction in the activity of BGUSs while displayed no impact on the overall fecal microbiome in mice. Furthermore, in the MMF-induced colitis model, the administration of OG at a dosage of 20 mg/kg effectively mitigated the gastrointestinal toxicity, and systematically reverted the colitis phenotypes. These findings indicate that the OG holds promising clinical potential for the prevention of MMF-induced gastrointestinal toxicity by inhibition of BGUSs and could be developed as a combinatorial therapy with MFF for better clinical outcomes.

Treatment access and satisfaction on disease-modifying therapies of neuromyelitis optica spectrum disorder patients in China: a cross-sectional survey

Background

Neuromyelitis optica spectrum disorder (NMOSD) is a rare and debilitating disease that has become more widely recognized in China. Legislative measures have been implemented by the government to improve treatment access for rare diseases.

Objectives

To investigate the diagnostic journey, treatment status, treatment accessibility, and treatment satisfaction of the NMOSD patients on disease-modifying therapies (DMTs) in China.

Design

A patient online survey.

Methods

This cross-sectional online survey was conducted between November 2022 and January 2023. Patients over 18 years old and diagnosed with NMOSD were included. The questionnaire consisted of five sections covering demographics, diagnostic and treatment experiences, DMTs availability, cost and affordability, and treatment satisfaction using the Treatment Satisfaction Questionnaire for Medication (version II). Patient opinions and demands were also collected at the end of the survey.

Results

A total of 375 patients diagnosed with NMOSD were recruited, of which 321 patients used DMTs. It required 1.22 ± 3.22 years and 3.58 ± 4.24 hospital visits for a definitive diagnosis. One-third of the patients still needed to travel for over 2 h to access DMTs. The total treatment expenditure was estimated to be CNY 59,827.00 (USD 8315.95) a year. Drug expenses alone accounted for 52.22% of the average annual household income. The most common challenges perceived were the inability to afford treatment and a lack of effective options. No significant difference was found in treatment satisfaction among DMTs, except that rituximab scored lowest in convenience compared to other DMTs. Patients' age and travel time required to obtain medications were negatively associated with global treatment satisfaction.

Conclusion

In China, patients with NMOSD face challenges in obtaining proper treatment due to diagnostic difficulties, distant medication access, and high costs. Policies should prioritize improving disease education and alleviating financial burdens for the patients.

Relapses and Serious Infections in Patients with Neuromyelitis Optica Spectrum Disorder Treated with Rituximab: A Swedish Single-Center Study

Neuromyelitis optica spectrum disorder (NMOSD) is a rare immune-mediated relapsing-remitting disease of the central nervous system. The usage of rituximab, as relapse-preventive therapy, in NMOSD is common. We performed a single-center retrospective cohort study to assess the risk of relapses and severe infectious events (SIEs) in rituximab-treated NMOSD patients. This study included 24 aquaporin-4 IgG+ (AQP4+), 8 myelin-oligodendrocyte-protein IgG+ (MOG+), and 10 double-seronegative NMOSD patients. Relapses were observed in 50% of all patients during a mean treatment time of 4.0 (range: 0.5-8.25) years. The incidence risk ratio (IRR) of relapse was three times higher in MOG+ compared to AQP4+ patients (IRR: 3.0, 95% confidence interval (CI); 1.2-7.7). SIEs occurred in 40% of all patients during follow-up. AQP4+ patients conferred an increased risk of SIEs compared to MOG+ patients (IRR; 5.3, 95% CI; 1.2-24.3). Incomplete CD19+ B-lymphocyte suppression was not correlated with relapse risk (hazard ratio; 1.9, 95% CI; 0.7-5.2), and there was no correlation between IgG-levels and SIE risk (odds ratio; 2.0, 95% CI; 0.8-4.8). In conclusion, considerable risks of both relapses and SIEs were observed in NMOSD patients exposed to rituximab, which underlines the need for close clinical vigilance of disease activity and infections during treatment.

Rituximab for Pediatric Central Nervous System Inflammatory Disorders in Alberta, Canada

BACKGROUND

Early and effective treatment of central nervous system (CNS) inflammatory disorders is vital to reduce neurologic morbidity and improve long-term outcomes in affected children. Rituximab is a B-cell-depleting monoclonal antibody whose off-label use for these disorders is funded in the province of Alberta, Canada, by the Short-Term Exceptional Drug Therapy (STEDT) program. This study describes the use of rituximab for pediatric CNS inflammatory disorders in Alberta.

METHODS

Rituximab applications for CNS inflammatory indications in patients <18 years of age were identified from the STEDT database between January 1, 2012, and December 31, 2019. Patient information was linked to other provincial datasets including the Discharge Abstract Database, Pharmaceutical Information Network, and Provincial Laboratory data. Analysis was descriptive.

RESULTS

Fifty-one unique rituximab applications were identified, of which 50 were approved. New applications increased from one in 2012 to a high of 12 in 2018. The most common indication was autoimmune encephalitis without a specified antibody (n = 16, 31%). Most children were approved for a two-dose (n = 33, 66%) or four-dose (n = 16, 32%) induction regimen. Physician-reported outcomes were available for 24 patients, of whom 14 (58%) were felt to have fully met outcome targets.

CONCLUSION

The use of rituximab for pediatric CNS inflammatory disorders has increased, particularly for the indication of autoimmune encephalitis. This study identified significant heterogeneity in dosing practices and laboratory monitoring. Standardized protocols for the use of rituximab in these disorders and more robust outcome reporting will help better define the safety and efficacy of rituximab in this population.

Update on the diagnosis and treatment of neuromyelitis optica spectrum disorders (NMOSD) - revised recommendations of the Neuromyelitis Optica Study Group (NEMOS). Part II: Attack therapy and long-term management

This manuscript presents practical recommendations for managing acute attacks and implementing preventive immunotherapies for neuromyelitis optica spectrum disorders (NMOSD), a rare autoimmune disease that causes severe inflammation in the central nervous system (CNS), primarily affecting the optic nerves, spinal cord, and brainstem. The pillars of NMOSD therapy are attack treatment and attack prevention to minimize the accrual of neurological disability. Aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) are a diagnostic marker of the disease and play a significant role in its pathogenicity. Recent advances in understanding NMOSD have led to the development of new therapies and the completion of randomized controlled trials. Four preventive immunotherapies have now been approved for AQP4-IgG-positive NMOSD in many regions of the world: eculizumab, ravulizumab - most recently-, inebilizumab, and satralizumab. These new drugs may potentially substitute rituximab and classical immunosuppressive therapies, which were as yet the mainstay of treatment for both, AQP4-IgG-positive and -negative NMOSD. Here, the Neuromyelitis Optica Study Group (NEMOS) provides an overview of the current state of knowledge on NMOSD treatments and offers statements and practical recommendations on the therapy management and use of all available immunotherapies for this disease. Unmet needs and AQP4-IgG-negative NMOSD are also discussed. The recommendations were developed using a Delphi-based consensus method among the core author group and at expert discussions at NEMOS meetings.

Bruton's tyrosine kinase-bearing B cells and microglia in neuromyelitis optica spectrum disorder

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory autoimmune disease of the central nervous system that involves B-cell receptor signaling as well as astrocyte-microglia interaction, which both contribute to evolution of NMOSD lesions.

MAIN BODY

Through transcriptomic and flow cytometry analyses, we found that Bruton's tyrosine kinase (BTK), a crucial protein of B-cell receptor was upregulated both in the blood and cerebrospinal fluid of NMOSD patients. Blockade of BTK with zanubrutinib, a highly specific BTK inhibitor, mitigated the activation and maturation of B cells and reduced production of causal aquaporin-4 (AQP4) autoantibodies. In a mouse model of NMO, we found that both BTK and pBTK expression were significantly increased in microglia. Transmission electron microscope scan demonstrated that BTK inhibitor ameliorated demyelination, edema, and axonal injury in NMO mice. In the same mice colocalization of GFAP and Iba-1 immunofluorescence indicated a noticeable increase of astrocytes-microglia interaction, which was alleviated by zanubrutinib. The smart-seq analysis demonstrated that treatment with BTK inhibitor instigated microglial transcriptome changes including downregulation of chemokine-related genes and genes involved in the top 5 biological processes related to cell adhesion and migration, which are likely responsible for the reduced crosstalk of microglia and astrocytes.

CONCLUSIONS

Our results show that BTK activity is enhanced both in B cells and microglia and BTK inhibition contributes to the amelioration of NMOSD pathology. These data collectively reveal the mechanism of action of BTK inhibition and corroborate BTK as a viable therapeutic target.

Early rituximab treatment reduces long-term disability in aquaporin-4 antibody-positive neuromyelitis optica spectrum

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) causes relapsing inflammatory attacks in the central nervous system, leading to disability. As rituximab, a B-lymphocyte-depleting monoclonal antibody, is an effective in preventing NMOSD relapses, we hypothesised that earlier initiation of rituximab can also reduce long-term disability of patients with NMOSD.

METHODS

This multicentre retrospective study involving 19 South Korean referral centres included patients with NMOSD with aquaporin-4 antibodies receiving rituximab treatment. Factors associated with the long-term Expanded Disability Status Scale (EDSS) were assessed using multivariable regression analysis.

RESULTS

In total, 145 patients with rituximab treatment (mean age of onset, 39.5 years; 88.3% female; 98.6% on immunosuppressants/oral steroids before rituximab treatment; mean disease duration of 121 months) were included. Multivariable analysis revealed that the EDSS at the last follow-up was associated with time to rituximab initiation (interval from first symptom onset to initiation of rituximab treatment). EDSS at the last follow-up was also associated with maximum EDSS before rituximab treatment. In subgroup analysis, the time to initiation of rituximab was associated with EDSS at last follow-up in patients aged less than 50 years, female and those with a maximum EDSS score ≥6 before rituximab treatment.

CONCLUSIONS

Earlier initiation of rituximab treatment may prevent long-term disability worsening in patients with NMOSD, especially among those with early to middle-age onset, female sex and severe attacks.

A Clinical Approach to Existing and Emerging Therapeutics in Neuromyelitis Optica Spectrum Disorder

PURPOSE OF REVIEW

Neuromyelitis optica spectrum disorder (NMOSD) is a rare but highly disabling disease of the central nervous system. Unlike multiple sclerosis, disability in NMOSD occurs secondary to relapses that, not uncommonly, lead to blindness, paralysis, and death. Recently, newer, targeted immunotherapies have been trialed and are now in the treatment arsenal. We have endeavoured to evaluate the current state of NMOSD therapeutics.

RECENT FINDINGS

This review provides a pragmatic evaluation of recent clinical trials and post-marketing data for rituximab, inebilizumab, satralizumab, eculizumab, and ravalizumab, contrasted to older agents. We also review contemporary issues such as treatment in the context of SARS-CoV2 infection and pregnancy. There has been a dramatic shift in NMOSD morbidity and mortality with earlier and improved disease recognition, diagnostic accuracy, and the advent of more effective, targeted therapies. Choosing a maintenance therapy remains nuanced depending on patient factors and accessibility. With over 100 putative agents in trials, disease-free survival is now a realistic goal for NMOSD patients.

Neuromyelitis Optica Spectrum Disorders: Clinical Perspectives, Molecular Mechanisms, and Treatments

Neuromyelitis optica (NMO) is a rare autoimmune inflammatory disorder affecting the central nervous system (CNS), specifically the optic nerve and the spinal cord, with severe clinical manifestations, including optic neuritis (ON) and transverse myelitis. Initially, NMO was wrongly understood as a condition related to multiple sclerosis (MS), due to a few similar clinical and radiological features, until the discovery of the AQP4 antibody (NMO-IgG/AQP4-ab). Various etiological factors, such as genetic-environmental factors, medication, low levels of vitamins, and others, contribute to the initiation of NMO pathogenesis. The autoantibodies against AQP4 target the AQP4 channel at the blood–brain barrier (BBB) of the astrocyte end feet, which leads to high permeability or leakage of the BBB that causes more influx of AQP4-antibodies into the cerebrospinal fluid (CSF) of NMO patients. The binding of AQP4-IgG onto the AQP4 extracellular epitopes initiates astrocyte damage through complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC). Thus, a membrane attack complex is formed due to complement cascade activation; the membrane attack complex targets the AQP4 channels in the astrocytes, leading to astrocyte cell damage, demyelination of neurons and oligodendrocytes, and neuroinflammation. The treatment of NMOSD could improve relapse symptoms, restore neurological functions, and alleviate immunosuppression. Corticosteroids, apheresis therapies, immunosuppressive drugs, and B cell inactivating and complement cascade blocking agents have been used to treat NMOSD. This review intends to provide all possible recent studies related to molecular mechanisms, clinical perspectives, and treatment methodologies of the disease, particularly focusing on recent developments in clinical criteria and therapeutic formulations.

Effectiveness of rituximab versus oral immunosuppressive therapies in neuromyelitis optica spectrum disorder in a racially diverse cohort of subjects: A single-center retrospective study

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune, inflammatory disorder characterized by severe relapses and high level of disability. In clinical trials of NMOSD, Black patients are under-represented, < 12%, compared to a relatively high prevalence of NMSOD in this population, 10/100,000. Despite the higher prevalence of NMOSD in Black and Asian patients, there is limited knowledge of the effectiveness of disease modifying treatments across racially diverse groups.

OBJECTIVE

To assess the effectiveness of rituximab and oral immunosuppressive agents in a cohort of NMOSD patients, the majority of whom are Black, in a real-world, clinical setting.

METHODS

A single-center retrospective study was conducted at the University of Chicago Medical Center.

INCLUSION CRITERIA

(1) diagnosis according to the 2015 International Panel for NMO Diagnosis (IPND) Criteria, (2) positive anti-aquaporin-4 antibodies on ELISA or cell-based tests, (3) initiation of immunosuppressant therapy within 5 years of disease onset, (4) first-line treatment with rituximab, mycophenolate (MMF), or azathioprine (AZA). Patients with negative anti-AQP4 titers were excluded. Kaplan-Meier survival analysis was used to estimate proportion of relapse-free patients following initiation of first line immunosuppressive therapy. A Cox proportional hazards regression model assessed the association of risk of relapsing with first-line immunosuppressive treatments with and without adjustments of pre-specified factors (age at disease onset, duration of disease, sex, race, CNS location of relapse).

RESULTS

7 of 29 patients (24%) receiving rituximab experienced a relapse within the first 3 years of treatment vs. 13 of 23 patients (57%) receiving either AZA or MMF. Within the first 6 months of treatment, 2 (6.9%) patients treated with rituximab experienced a relapse vs. 7 (30.4%) patients treated with either MMF or AZA. In the 29 patients treated with rituximab, the 1-year and 3-year proportion of relapse-free patients was 88.8% and 70.9%. For the 23 patients treated with either AZA or MMF, the 1-year and 3-year proportion of relapse-free patients was 69.5% and 38.7%. In the univariate analysis, the risk of relapse was significantly higher in patients treated with AZA or MMF compared to those treated with rituximab (hazard ratio [HR] of 2.48 [0.99 - 6.21]; p = 0.046).

CONCLUSION

In this real-world study involving a majority of Black NMOSD patients, rituximab was relatively more effective in preventing relapses within 3 years of therapy initiation than AZA and MMF. Rituximab remains an effective option for treating NMOSD, especially when there are delays in treatment due to access and economic issues associated with newer treatments.

Pathophysiology of myelin oligodendrocyte glycoprotein antibody disease

Myelin Oligodendrocyte Glycoprotein Antibody Disease (MOGAD) is a spectrum of diseases, including optic neuritis, transverse myelitis, acute disseminated encephalomyelitis, and cerebral cortical encephalitis. In addition to distinct clinical, radiological, and immunological features, the infectious prodrome is more commonly reported in MOGAD (37-70%) than NMOSD (15-35%). Interestingly, pediatric MOGAD is not more aggressive than adult-onset MOGAD, unlike in multiple sclerosis (MS), where annualized relapse rates are three times higher in pediatric-onset MS. MOGAD pathophysiology is driven by acute attacks during which T cells and MOG antibodies cross blood brain barrier (BBB). MOGAD lesions show a perivenous confluent pattern around the small veins, lacking the radiological central vein sign. Initial activation of T cells in the periphery is followed by reactivation in the subarachnoid/perivascular spaces by MOG-laden antigen-presenting cells and inflammatory CSF milieu, which enables T cells to infiltrate CNS parenchyma. CD4+ T cells, unlike CD8+ T cells in MS, are the dominant T cell type found in lesion histology. Granulocytes, macrophages/microglia, and activated complement are also found in the lesions, which could contribute to demyelination during acute relapses. MOG antibodies potentially contribute to pathology by opsonizing MOG, complement activation, and antibody-dependent cellular cytotoxicity. Stimulation of peripheral MOG-specific B cells through TLR stimulation or T follicular helper cells might help differentiate MOG antibody-producing plasma cells in the peripheral blood. Neuroinflammatory biomarkers (such as MBP, sNFL, GFAP, Tau) in MOGAD support that most axonal damage happens in the initial attack, whereas relapses are associated with increased myelin damage.

B-cell proliferation characteristics and monitoring significance under the modified reduced-dose rituximab regimen for NMOSD: A real-world case series study

OBJECTIVE

To explore the B-cell proliferation characteristics and monitoring significance under the modified reduced-dose rituximab (mRTX) regimen for neuromyelitis optica spectrum disorder (NMOSD).

METHODS

NMOSD patients treated with mRTX were recruited, and the percentages of total CD19⁺ B cells and CD27⁺ memory B cells were dynamically detected by flow cytometry. The annualized relapse rate (ARR) and expanded disability status scale (EDSS) scores were compared before and after mRTX treatment, and the differences in B-cell values were compared between groups.

RESULTS

A total of 34 patients with NMOSD were ultimately enrolled. The EDSS score decreased from 2.5 (1.5, 3.0) to 1.3 (1.0, 2.0), and the ARR decreased from 1.0 (0, 2.0) to 0 (0, 0) (p < 0.001). Relapses occurred in 6 patients, with total CD19⁺ B-cell percentages of 3.25% (2.7%, 3.7%) and CD27⁺ memory B-cell percentages of 0.3% (0.2%, 0.3%) at initial relapse. Twenty-eight patients (82.4%) remained relapse-free with 84 doses of mRTX. Before 56 repeated doses, the total CD19⁺ B cells and CD27⁺ memory B cells were 4.00% (3.14%, 5.32%) and 0.26% (0.17%, 0.40%), respectively. The mean dosing interval was 9.2 months. Both total CD19⁺ B cells and CD27⁺ memory B cells proliferated over time after mRTX use, with significantly faster proliferation rates in the later stages. In 28 relapse-free patients, the mean time to reach 1% for total CD19⁺ B cells was 210 days, and the mean time to reach 3% was 240 days, with the mean interval from 1% to 3% of 65 days. Twenty-five relapse-free patients had no significant differences in maximum, minimum, and mean B-cell values compared to those of 6 patients with relapse.

CONCLUSION

The high rate of B-cell proliferation under the mRTX regimen indicates that closer dynamic B-cell monitoring is required to guide repeated mRTX dosing. Sustained depletion of total CD19⁺ B cells targeting < 3% of lymphocytes may be feasible, enabling extended dosing intervals.

A comparison of the efficacy of tocilizumab versus azathioprine for neuromyelitis optica spectrum disorder: A study protocol for systematic review and meta-analysis

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a chronic inflammatory disease of the nervous system, which is frequently accompanied by a pathological humoral immune response against aquaporin-4 water channel. The most common feature of the disorder is recurrent episodes of longitudinally extensive transverse myelitis and optic neuritis. Frequent relapse leads to the gradual accumulation of neurological dysfunction. Azathioprine (AZA) is an empirical attack -preventive immunotherapies drug to prevent the relapse of NMOSD, and tocilizumab (TCZ) has been also reported reduce the activity of NMOSD. Therefore, we designed this systematic review and meta-analysis to evaluate the efficacy between TCZ and AZA in the treatment of NMOSD patients.

METHODS

This study followed the PRISMA guidelines. We searched the English literature between 2000 and 2022 by using relevant medical subject heading and entry terms in PubMed, MEDLINE, Embase and CENTRAL databases. A meta-analysis of drug efficacy was performed using expanded disability status scale score and annualized relapse rate (ARR) as the primary outcome indicators.

RESULTS

The literature search found a total of 1546 articles about TCZ and AZA in the treatment of NMOSD, 27 of which were included in this study after a series of screening. 930 and 148 patients with NMOSD were enrolled, who had been treated with AZA and TCZ, respectively. The pooled standardized mean difference (SMD) of expanded disability status scale score before and after AZA treated was -0.40 (95%CI: -0.50, -0.30) (I2 = 65.4%, P < .001), before and after TCZ treated was -0.84 (95%CI: -1.08, -0.60) (I2 = 45.6%, P = .076). The SMD of ARR before and after AZA treated was -1.01 (95%CI: -1.12, -0.90) (I2 = 83.4%, P < .001), before and after TCZ treated was -1.27 (95%CI: -1.52, -1.03) (I2 = 52.7%, P = .039). In addition, TCZ reduce ARR more significantly compared with AZA (P = .031).

CONCLUSION

The results of this study showed that the treatment of NMOSD patients with AZA and TCZ are associated with decreased number of relapses and disability improvement as well. In addition, compared with AZA, TCZ more significantly reduce ARR.

Multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) following COVID-19 vaccines: A systematic review

BACKGROUND

The global COVID-19 pandemic began in March 2019, and given the number of casualties and adverse effects on the economy, society, and all aspects of the health system, efforts have been made to develop vaccines from the beginning of the pandemic. Numerous vaccines against COVID-19 infection have been developed in several technologies and have spread rapidly. There have been reported multiple complications of the COVID-19 vaccines as with other vaccines. A number of studies have reported multiple sclerosis (MS ) and neuromyelitis optica spectrum disorder (NMOSD) as complications of COVID-19 vaccines.

METHODS

First, we found 954 studies from 4 databases (PubMed, Embase, Scopus, and Web of Science) from inception to March 1^st, 2022. Next, duplicate articles were eliminated, and 476 studies remained. Then 412 studies were removed according to inclusion and exclusion criteria. After obtaining the full text of 64 articles, 12 studies were selected finally.

RESULTS

The data were extracted from included studies in a table. Our data includes demographic data, comorbidities, vaccines information and side effects, NMOSD and MS symptoms, laboratory and cerebrospinal fluid (CSF) findings, magnetic resonance imaging (MRI) results, treatment, and outcome of all cases.

CONCLUSION

MS and NMOSD are two neuroinflammatory disorders that arise in the CNS. Cases of MS and NMOSD have been reported following COVID-19 vaccination. Nevertheless, more studies with more subjects are needed to assess any possible relationship between the COVID-19 vaccine and central nervous system demyelination.

Therapeutic strategies in NMOSD and MOGAD patients: A multicenter cohort study in Latin America

PURPOSE

This study describes the therapeutic strategies in NMOSD and MOGAD adopted by neurologists to treat both conditions in Latin America (LATAM) with main focus on rituximab (RTX) and the disease outcome.

METHODS

retrospective study in a cohort of NMOSD and MOGAD patients followed in specialized MS/NMOSD centers from eight countries and 14 LATAM reference centers. Demographics and clinical characteristics were collected. RTX strategies on naïve (for rituximab) patients were summarized as follows: scheme A: two 1000 mg infusions 15 days apart and repeated every 6 months; scheme B: four 375 mg/m2 infusions every week for 4 weeks and repeated every 6 months; scheme C: one 1000 mg infusions and repeated every 6 months; scheme D: other scheme used. Relapse rate and adverse events during follow-up were analyzed considering the different RTX schemes. Poisson and logistic regression analysis were used to assess baseline aspects and disease activity during follow-up.

RESULTS

A total of 217 patients were included. 197 were NMOSD patients (164, 83.2% AQP4-IgG seropositive and 16.7% seronegative) and 20 were MOGAD patients. The most frequent long-term treatment was RTX in both groups (48.2% and 65% for NMOSD and MOGAD patients, respectively). The most common RTX regimen used in 79 (83.1%) patients was two 1000 mg infusions 15 days apart and repeat every 6 months. Relapses under RTX treatment were observed in 21 (22.1%) patients. Relapses after RTX treatment were associated with higher EDSS (OR 1.75, 95%CI 1.44-2.34, p = 0.03) and higher ARR pre-RTX (OR = 2.17, 95% CI 1.72-3.12, p = 0.002) but not with RTX regimen (OR = 1.10, 95% CI 0.89-1.21, p = 0.60).

CONCLUSION

the most strategy used in LATAM was RTX with two 1000 mg infusions 15 days apart. Relapses during follow up were not associated with RTX regimen used.

Efficacy and safety of rituximab in myelin oligodendrocyte glycoprotein antibody-associated disorders compared with neuromyelitis optica spectrum disorder: a systematic review and meta-analysis

BACKGROUND

Rituximab (RTX) efficacy in patients with myelin oligodendrocyte glycoprotein (MOG) antibody-associated disorders (MOGADs) is still poorly understood, though it appears to be lower than in aquaporin-4-IgG-positive neuromyelitis optica spectrum disorders (AQP4-IgG+NMOSDs). The aim of this systematic review and meta-analysis is to assess the efficacy and safety profile of RTX in patients with MOGAD and to compare RTX efficacy between MOGAD and AQP4-IgG+NMOSD.

METHODS

We searched original English-language articles published between 2012 and 2021 in MEDLINE, Cochrane, Central Register of Controlled Trials and clinicaltrials.gov, reporting data on RTX efficacy in patients with MOGAD. The main outcome measures were annualised relapse rate (ARR) and Expanded Disability Status Scale (EDSS) score mean differences (MDs) after RTX. The meta-analysis was performed with a random effects model. Covariates associated with the outcome measures were analysed with a linear meta-regression.

RESULTS

The systematic review included 315 patients (138 women, mean onset age 26.8 years) from 32 studies. Nineteen studies (282 patients) were included in the meta-analysis. After RTX, a significant decrease of ARR was found (MD: -0.92, 95% CI -1.24 to -0.60, p<0.001), markedly different from the AQP4-IgG+NMOSD (MD: -1.73 vs MOGAD -0.92, subgroup difference testing: Q=9.09, p=0.002). However, when controlling for the mean ARR pre-RTX, this difference was not significant. After RTX, the EDSS score decreased significantly (MD: -0.84, 95% CI -1.41 to -0.26, p=0.004). The frequency of RTX-related adverse events was 18.8% (36/192) and overall RTX-related mortality 0.5% (1/192).

CONCLUSIONS

RTX showed effective in MOGAD, although to a lesser extent than in AQP4-IgG+NMOSD, while the safety profile warrants some caution in its prescription. Randomised-controlled trials are needed to confirm these findings and provide robust evidence to improve treatment strategies in patients with MOGAD.

PROSPERO REGISTRATION NUMBER

CRD42020175439.

Age of onset correlates with clinical characteristics and prognostic outcomes in neuromyelitis optica spectrum disorder

Objective

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease preferentially affects the optic nerve and the spinal cord. The first attack usually occurs in the third or fourth decade, though patients with disease onset in the fifties or later are not uncommon. This study aimed to investigate the clinical characteristics and prognosis in patients with different age of onset and to explore the correlations between age of onset and clinical characteristics and prognostic outcomes.

Method

We retrospectively reviewed the medical records of 298 NMOSD patients diagnosed according to the 2015 updated version of diagnostic criteria. Patients were divided into early-onset NMOSD (EO-NMOSD) (<50 years at disease onset) and late-onset NMOSD (LO-NMOSD) (≥50 years at disease onset) based on the age of disease onset. LO-NMOSD patients were divided into two subgroups: relative-late-onset NMOSD (RLO-NMOSD) (50~70 years at disease onset) and very-late-onset NMOSD (≥70 years at disease onset). Clinical characteristics, laboratory findings, neuroimaging features, and prognostic outcomes were investigated.

Results

Compared to EO-NMOSD patients, patients with LO-NMOSD showed more frequent transverse myelitis (TM) (58.20% vs. 36.00%, p = 0.007) while less frequent optic neuritis (ON) (23.10% vs. 34.80%, p = 0.031) and brainstem/cerebral attacks (7.50% vs. 18.30%, p = 0.006) as the first attack. Patients with LO-NMOSD showed less frequent relapses, higher Expanded Disability Status Scale (EDSS) score at the last follow-up, fewer NMOSD-typical brain lesions, and longer segments of spinal cord lesions. Patients with older onset age showed a higher proportion of increased protein levels in cerebrospinal fluid during the acute phase of attacks. Age at disease onset positively correlated with length of spinal cord lesions at first attack and at last follow-up, negatively correlated with ARR-1 (ARR excluding the first attack, calculated from disease onset to final follow-up), irrespective of AQP4-IgG serostatus. Patients with older age at disease onset progressed to severe motor disability sooner, and age of onset positively correlated with EDSS score at the last follow-up, irrespective of AQP4-IgG serostatus.

Conclusion

Age of disease onset affects clinical characteristics and prognosis outcomes of patients with NMOSD.

Eculizumab for acute relapse of neuromyelitis optica spectrum disorder: Case report

Introduction

Eculizumab has been shown to be an effective and typically well-tolerated medication in the treatment of neuromyelitis optica spectrum disorder (NMOSD) in maintaining disease remission in patients who are aquaporin-4 water channel autoantibody (AQP4-IgG) seropositive. The efficacy of eculizumab in an acute relapse of NMOSD however is still under review.

Case

We describe a 46 year-old female who presented with acute left monocular vision loss on a background of bilateral optic neuritis treated 15 years prior as suspected NMOSD. She had very poor vision from the right eye (6/60). On presentation she was not on any long-term immunosuppressive agents. Her serum was positive for AQP4-IgG and MRI brain and spine demonstrated areas of demyelination in the corpus callosum and thoracic spine. She was treated with high dose intravenous methylprednisolone and underwent plasmapheresis for five consecutive days, but continued to clinically deteriorate with ongoing blindness in her left eye (light perception only). She was subsequently administered eculizumab with weaning oral corticosteroids. Clinically her vision improved to counting fingers and she remains on maintenance eculizumab infusions in the community. At 3 months, there is a steady improvement but still significant loss of central vision from that eye.

Conclusion

The utility of eculizumab in NMOSD may assist with treating acute episodes. This theoretically accords with the mode of action in inhibiting conversion of C5–C5a/b, perhaps arresting the acute inflammatory process in this disease. Given that disease burden and mortality in NMOSD is almost entirely related to relapses, increased use of eculizumab acutely could potentially aid recovery from an attack in very severe attacks, and therefore minimize immediate stepwise accrual of disability.

Deep learning-based relapse prediction of neuromyelitis optica spectrum disorder with anti-aquaporin-4 antibody

Objective

We previously identified the independent predictors of recurrent relapse in neuromyelitis optica spectrum disorder (NMOSD) with anti-aquaporin-4 antibody (AQP4-ab) and designed a nomogram to estimate the 1- and 2-year relapse-free probability, using the Cox proportional hazard (Cox-PH) model, assuming that the risk of relapse had a linear correlation with clinical variables. However, whether the linear assumption fits real disease tragedy is unknown. We aimed to employ deep learning and machine learning to develop a novel prediction model of relapse in patients with NMOSD and compare the performance with the conventional Cox-PH model.

Methods

This retrospective cohort study included patients with NMOSD with AQP4-ab in 10 study centers. In this study, 1,135 treatment episodes from 358 patients in Huashan Hospital were employed as the training set while 213 treatment episodes from 92 patients in nine other research centers as the validation set. We compared five models with added variables of gender, AQP4-ab titer, previous attack under the same therapy, EDSS score at treatment initiation, maintenance therapy, age at treatment initiation, disease duration, the phenotype of the most recent attack, and annualized relapse rate (ARR) of the most recent year by concordance index (C-index): conventional Cox-PH, random survival forest (RSF), LogisticHazard, DeepHit, and DeepSurv.

Results

When including all variables, RSF outperformed the C-index in the training set (0.739), followed by DeepHit (0.737), LogisticHazard (0.722), DeepSurv (0.698), and Cox-PH (0.679) models. As for the validation set, the C-index of LogisticHazard outperformed the other models (0.718), followed by DeepHit (0.704), DeepSurv (0.698), RSF (0.685), and Cox-PH (0.651) models. Maintenance therapy was calculated to be the most important variable for relapse prediction.

Conclusion

This study confirmed the superiority of deep learning to design a prediction model of relapse in patients with AQP4-ab-positive NMOSD, with the LogisticHazard model showing the best predictive power in validation.

Saudi consensus recommendations on the management of multiple sclerosis: MS management in children and adolescents

Multiple sclerosis (MS) most commonly presents in young adults, although 3-5% of patients develop MS prior to the age of 18 years. The new and comprehensive consensus for the management of MS in Saudi Arabia includes recommendations for the management of MS and other CNS inflammatory demyelinating disorders in pediatric and adolescent patients. This article summarizes the key recommendations for the diagnosis and management of these disorders in young patients. Pediatric and adult populations with MS differ in their presentation and clinical course. Careful differential diagnosis is important to exclude alternative diagnoses such as acute disseminated encephalomyelitis (ADEM) or neuromyelitis optica spectrum disorders (NMOSD). The diagnosis of MS in a pediatric/adolescent patient is based on the 2017 McDonald diagnostic criteria, as in adults, once the possibility of ADEM or NMOSD has been ruled out. Few data are available from randomized trials to support the use of a specific disease-modifying therapy (DMT) in this population. Interferons and glatiramer acetate are preferred initial choices for DMTs based on observational evidence, with the requirement of a switch to a more effective DMT if breakthrough MS activity occurs.

Progress in treatment of neuromyelitis optica spectrum disorders (NMOSD): Novel insights into therapeutic possibilities in NMOSD

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune inflammatory demyelinating disorder of the central nervous system (CNS), which is a severely disabling disorder leading to devastating sequelae or even death. Repeated acute attacks and the presence of aquaporin-4 immunoglobulin G (AQP4-IgG) antibody are the typical characteristics of NMOSD. Recently, the phase III trials of the newly developed biologicals therapies have shown their effectiveness and good tolerance to a certain extent when compared with the traditional therapy with the first- and second-line drugs. However, there is still a lack of large sample, double-blind, randomized, clinical studies to confirm their efficacy, safety, and tolerability. Especially, these drugs have no clear effect on NMOSD patients without AQP4-IgG and refractory patients. Therefore, it is of strong demand to further conduct large sample, double-blind, randomized, clinical trials, and novel therapeutic possibilities in NMOSD are discussed briefly here.

Neuromyelitis Optica Spectrum Disorder With Anti-Aquaporin-4 Antibody: Outcome Prediction Models

Background

Recognizing the predictors of disease relapses in patients with anti-aquaporin-4 antibody (AQP4-ab)-positive neuromyelitis optica spectrum disorder (NMOSD) is essential for individualized treatment strategy. We aimed to identify the factors that predicted relapses among patients with AQP4-ab-positive NMOSD, develop outcome prediction models, and validate them in a multicenter validation cohort.

Methods

Between January 2015 and December 2020, 820 patients with NMOSD were registered at Huashan Hospital. We retrospectively reviewed their medical records, and included 358 AQP4-ab-positive patients with 1135 treatment episodes. Univariate and multivariate analyses were used to explore the predictors of relapse, severe visual or motor disability during follow-up. A model predicting the 1- and 2-year relapse-free probability was developed and validated in an external validation cohort of 92 patients with 213 treatment episodes.

Results

Lower serum AQP4-ab titer (< 1:100), higher Expanded Disability Status Scale (EDSS) score at onset (≥ 2.5), and use of intravenous methylprednisolone (IVMP) at the first attack predicted an overall lower annualized relapse rate. Older age (> 48 years), optic neuritis at onset, and higher onset EDSS score (≥ 2.5) significantly increased the risk for blindness, while IVMP at the first attack and maintenance therapy reduced the risk for blindness. Myelitis at onset increased the possibility of motor disability (EDSS ≥ 6.0), severe motor disability or death (EDSS ≥ 8.0), while maintenance therapy reduced these possibilities. Anderson and Gill model identified that the risk factors predicting recurrent relapses under certain treatment status were female gender, high AQP4-ab titer (≥ 1:100), previous attack under same therapy, lower EDSS score at treatment initiation (< 2.5), and no maintenance therapy or oral prednisone lasting less than 6 months. A nomogram using the above factors showed good discrimination and calibration abilities. The concordance indexes in the primary and validation cohort were 0.66 and 0.65, respectively.

Conclusion

This study reports the demographic, clinical and therapeutic predictors of relapse, and severe visual or motor disability in NMOSD. Early identification of patients at risk of unfavorable outcomes is of paramount importance to inform treatment decisions.

Adverse Events in NMOSD Therapy

Neuromyelitis optica spectrum disorders (NMOSD) are rare neurologic autoimmune diseases that have a poor prognosis if left untreated. For many years, generic oral immunosuppressants and repurposed monoclonal antibodies that target the interleukin-6 pathway or B cells were the mainstays of drug treatment. Recently, these drug treatments have been complemented by new biologics developed and approved specifically for NMOSD. In principle, all of these drugs are effective, but treatment recommendations that take this into account are still pending. Instead, the choice of a drug may depend on other criteria such as drug safety or tolerability. In this review, we summarise current knowledge on the adverse effects of azathioprine, mycophenolate mofetil, rituximab, tocilizumab, eculizumab, satralizumab, and inebilizumab in NMOSD. Infections, cytopenias, and infusion-related reactions are most common, but the data are as heterogeneous as the manifestations are diverse. Nevertheless, knowledge of safety issues may facilitate treatment choices for individual patients.

Late-onset Neuromyelitis Optica Spectrum Disorder with Anti-AQP4 and Anti-MOG Antibodies

OBJECTIVE

This study aimed to evaluate the clinical characteristics and prognosis of late-onset (≥ 50 years) neuromyelitis optica spectrum disorder (LO-NMOSD), and compare them with those of early-onset (< 50 years) NMOSD (EO-NMOSD) and NMOSD with various antibody serostatuses.

METHODS

From January 2015 to December 2020, 360 anti-aquaporin-4 antibody (AQP4-ab)-positive and 130 anti-myelin oligodendrocyte glycoprotein antibody (MOG-ab)-positive patients presented to the Huashan Hospital, China. We retrospectively reviewed their medical records, including the Expanded Disability Status Scale (EDSS) score at each visit and the annualized relapse rate (ARR). Prognostic outcomes included the time to first relapse, blindness, motor dysfunction, severe motor dysfunction, and death. Correlations between the age at onset, lesion location, and clinical parameters were analyzed.

RESULTS

This study included 122 (24.9%) patients with LO-NMOSD, 101 with AQP4-ab and 21 with MOG-ab. Compared with EO-NMOSD patients, those with LO-NMOSD had higher EDSS scores, more frequent disease onset with transverse myelitis, blindness, motor dysfunction, and severe motor dysfunction. Compared with LO-NMOSD patients with MOG-ab, those with AQP4-ab had a worse prognosis. Age at disease onset had a significantly positive correlation with EDSS score at the last follow-up of all NMOSD patients, but a negative correlation with ARR-1 (ARR excluding the first attack, calculated from disease onset to final follow-up) in NMOSD patients with AQP4-ab.

CONCLUSIONS

Patients with LO-NMOSD, especially those with AQP4-ab, had a worse prognosis compared with patients with EO-NMOSD. Age at disease onset and antibody serostatus predicted blindness and motor dysfunction.

Evaluation of effect of empirical attack-preventive immunotherapies in neuromyelitis optica spectrum disorders: An update systematic review and meta -analysis

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease of the central nervous system, which mainly involves the optic nerve and spinal cord. Frequent relapse can accumulate the degree of disability. At present, the main treatment options are immunosuppressants and blood purification. The first-line immunosuppressants for NMOSD are mainly rituximab (RTX), mycophenolate mofetil (MMF) and azathioprine (AZA). Therefore, we designed this systematic review and meta-analysis to evaluate the safety and effect of the above three drugs in the treatment of NMOSD patients.

METHODS

The following Medical Subject Heading (MeSH) and related entry terms are used to search English literature in PubMed, MEDLINE and CENTRAL databases, respectively. MeSH include: Neuromyelitis optic and Rituximab or Azathioprine or Mycophenolate Mofetil; entry terms include: NMO Spectrum Disorder, NMO Spectrum Disorders, Neuromyelitis Optica (NMO) Spectrum Disorder, Neuromyelitis Optica Spectrum Disorders, Devic Neuromyelitis Optica, Neuromyelitis Optica, Devic, Devic's Disease, Devic Syndrome, Devic's Neuromyelitis Optica, Neuromyelitis Optica (NMO) Spectrum Disorders, CD20 Antibody, Rituximab CD20 Antibody, Mabthera, IDEC-C2B8 Antibody, GP2013, Rituxan, Mycophenolate Mofetil, Mofetil, Mycophenolate, Mycophenolic Acid, Morpholinoethyl Ester, Cellcept, Mycophenolate Sodium, Myfortic, Mycophenolate Mofetil Hydrochloride, Mofetil Hydrochloride, Mycophenolate, RS 61443, RS-61443, RS61443, azathioprine sodium, azathioprine sulfate (note: literature retrieval operators "AND" "OR" "NOT" are used to link MeSH with Entry Terms.) The literature search found a total of 3058 articles about rituximab, mycophenolate mofetil and azathioprine in the treatment of NMOSD, 63 of which were included in this study after a series of screening.

RESULTS

930,933,732 patients with NMOSD were enrolled, who had been treated with MMF, AZA and RTX, respectively. The pooled standardized mean difference (SMD) of EDSS before and after RTX treated was -0.58 (95%CI: -0.72, -0.44) (I² = 0%, p = 0.477), before and after MMF treated was -0.47 (95%CI: -0.73, -0.21) (I² = 85.6%, p<0.001), before and after AZA treated was -0.41 (95%CI: -0.60, -0.23) (I² = 65.4%, p<0.001). there was no significant difference in the effect of the three drugs on reducing EDSS scores (RTX vs MMF, p = 0.522; RTX vs AZA, p = 0.214; MMF vs AZA, p = 0.732). The pooled standardized mean difference (SMD) of ARR before and after RTX treated was -1.45 (95%CI: -1.72, -1.18) (I² = 72.4%, p<0.001), before and after MMF treated was -1.14 (95%CI: -1.31, -0.97) (I² = 54.5%, p<0.001), before and after AZA treated was -1.11 (95%CI: -1.39, -0.83) (I² = 83.4%, p<0.001). RTX significantly reduced ARR compared with the other two drugs (RTX vs MMF, p = 0.039; RTX vs AZA, p = 0.049; MMF vs AZA, p = 0.436).

CONCLUSION

The results of this systematic review and meta-analysis showed that the treatment of NMOSD patients with RTX, MMF and AZA is associated with decreased number of relapses and disability improvement as well, and there was no significant difference in the effect of the three drugs on reducing EDSS scores, but RTX significantly reduced ARR compared with the other two drugs.

Pathogenic antibodies to AQP4: Neuromyelitis optica spectrum disorder (NMOSD)

NMOSD is a rare but severe relapsing remitting demyelinating disease that affects both adults and children. Most patients have pathogenic antibodies that target the central nervous system AQP4 protein. This review provides an update on our current understanding of the disease pathophysiology and describes the clinical, paraclinical features and therapeutic management of the disease.

Hope for patients with neuromyelitis optica spectrum disorders - from mechanisms to trials

Neuromyelitis optica spectrum disorder (NMOSD) is a rare inflammatory CNS disease that primarily manifests as relapsing episodes of severe optic neuritis and myelitis. Diagnosis of NMOSD is supported by the detection of IgG autoantibodies that target the aquaporin 4 (AQP4) water channel, which, in the CNS, is an astrocyte-specific protein. AQP4 antibody binding leads to AQP4 internalization, complement-dependent and antibody-dependent cellular cytotoxicity, and water channel dysfunction. Cumulative attack-related injury causes disability in NMOSD, so the prevention of attacks is expected to prevent disability accrual. Until recently, no regulator-approved therapies were available for NMOSD. Traditional immunosuppressant therapies, including mycophenolate mofetil, azathioprine and rituximab, were widely used but their benefits have not been assessed in controlled studies. In 2019 and 2020, five phase II and III randomized placebo-controlled trials of four mechanism-based therapies for NMOSD were published and demonstrated that all four effectively prolonged the time to first relapse. All four drugs were monoclonal antibodies: the complement C5 antibody eculizumab, the IL-6 receptor antibody satralizumab, the B cell-depleting antibody inebilizumab, which targets CD19, and rituximab, which targets CD20. We review the pathophysiology of NMOSD, the rationale for the development of these mechanism-based drugs, the methodology and outcomes of the five trials, and the implications of these findings for the treatment of NMOSD.

Treatment response, risk of relapse and clinical characteristics of Taiwanese patients with neuromyelitis optica spectrum disorder

BACKGROUND/PURPOSE

The long-term disease course and efficacy of maintenance therapies have rarely been investigated in Asian patients with neuromyelitis optica spectrum disorder (NMOSD).

METHODS

Medical records of patients fulfilling the 2015 International Consensus Diagnostic Criteria for NMOSD at three medical centers in Taiwan were systematically analyzed. Linear regression analysis was performed to investigate factors related to annualized relapse rate (ARR); survival analysis was used to estimate the relapse-free intervals among therapies.

RESULTS

A total of 557 relapses affecting 648 regions (202 optic neuritis, 352 acute myelitis, and 94 brain syndromes) in 204 patients were analyzed during a follow-up period of 69.5 months (range, 1-420). Up to 36.1% of myelitis-onset patients and 24.0% of optic neuritis-onset patients exhibited a limited form disease, defined as having one or more relapses confined to the same region. The median ARR was significantly lower in patients with limited form disease than those with relapses involving multiple regions (0.30 vs. 0.47, respectively). An older age at disease onset was associated with a lower ARR (p = 0.023). Kaplan-Meier analysis showed that the estimated time (months) to next relapse was longest in rituximab-treatment group (58.0 ± 13.2), followed by immunosuppressant (48.5 ± 4.8) or prednisone (29.6 ± 4.6) groups, and shortest in those without maintenance therapy (27.6 ± 4.2) (p = 8.1 × 10^-7).

CONCLUSION

Limited form disease and older age at disease onset are associated with a lower relapse rate in NMOSD. Compared to no maintenance therapy, rituximab and immunosuppressant significantly reduce the relapse risks.

Efficacy and safety of modified reduced-dose rituximab in Chinese patients with neuromyelitis optica spectrum disorder: A retrospective cohort study

OBJECTIVE

To evaluate the long-term efficacy and safety of a modified reduced-dose rituximab (mRTX) regimen compared with azathioprine (AZA) and mycophenolate mofetil (MMF) in Chinese patients with neuromyelitis optica spectrum disorder (NMOSD).

METHODS

In this retrospective cohort study, 71 patients with NMOSD were treated with AZA (n = 24), MMF (n = 18), or mRTX (n = 29). The primary outcome was initial relapse after first-line immunosuppressant therapy. The annualized relapse rate (ARR), expanded disability status scale (EDSS) score, activities of daily living (ADL) scale score, and treatment-related adverse events were compared between groups.

RESULTS

Significant ARR reductions were observed in the three groups, with relapse-free rates of 37.5%, 72.2%, and 79.3% in the AZA, MMF, and RTX groups, respectively. Compared with AZA, mRTX and MMF significantly reduced the NMOSD relapse risk. Relapse within 1 year before immunosuppressant therapy or ARR before immunosuppressant therapy increased the NMOSD relapse risk. mRTX and MMF were superior to AZA in reducing the EDSS score and increasing the ADL score, but there was no significant difference between the mRTX and MMF groups. Additionally, mRTX-treated patients were less likely to use steroids concurrently than those treated with AZA and MMF. The adverse event rate in the AZA group was relatively higher than that in the MMF and mRTX groups, though no significant difference was noted among the three groups.

CONCLUSIONS

Compared with AZA, mRTX and MMF significantly reduced the NMOSD relapse risk. mRTX-treated patients presented less concomitant steroid use than those treated with AZA and MMF, fewer adverse events, and better tolerance.

Efficacy of azathioprine, mycophenolate mofetil, and rituximab in the treatment of neuromyelitis optica spectrum disorder and analysis of prognostic factors

OBJECTIVE

The study aims to compare the efficacies of the immunosuppressants most commonly prescribed for patients with neuromyelitis optica spectrum disorder (NMOSD). The predictors, which might be associated with relapse and disability in NMOSD, were also analyzed.

METHODS

This retrospective study included NMOSD patients treated with azathioprine (AZA), mycophenolate mofetil (MMF), and rituximab (RTX). The annual relapse rate (ARR) and the incidence rates of adverse events were compared. Cox proportional-hazards model calculated the potential predictors of NMOSD relapse and disability.

RESULTS

A total of 83 patients were included. The median treatment time of AZA group (n = 34), MMF group (n = 20), and RTX group (n = 29) were 19.5, 15.5, and 12 months, respectively. ARR of the three groups reduced significantly after treatment. In the three groups, 55.9%, 50%, and 79.3% of patients, respectively, were free from relapse. However, the difference among the three groups was of no statistical significance, possibly due to the small sample size. During the treatment, 32.4%, 15%, and 24.1% of patients experienced adverse events in the AZA group, MMF group, and RTX group, respectively. Additionally, the multivariate Cox analyses indicated that history of a severe attack and disease duration were associated with the risk of relapse after immunotherapy. Late-onset (≥ 50 years old) NMOSD patients were probably more susceptible to motor disability, and those with optic neuritis at onset were more likely to develop visual disability.

CONCLUSIONS

AZA, MMF, and low-dose RTX were all effective in reducing the relapse rate in NMOSD. The age at onset, disease duration, history of severe attacks, and primary syndromes might be significant prognostic predictors in NMOSD.

A meta-analysis comparing first-line immunosuppressants in neuromyelitis optica

Objective

As phase III trials have shown interest in innovative but expensive drugs in the treatment of neuromyelitis optica spectrum disorder (NMOSD), data are needed to clarify strategies in the treatment of neuromyelitis optica (NMO). This meta‐analysis compares the efficacy of first‐line strategies using rituximab (RTX), mycophenolate mofetil (MMF), or azathioprine (AZA), which are still widely used.

Methods

Studies identified by the systematic review of Huang et al. (2019) were selected if they considered at least two first‐line immunosuppressants among RTX, MMF, and AZA. We updated this review. The Medline, Cochrane Central Register of Controlled Trials, Embase, and ClinicalTrials databases were queried between November 2018 and April 2020. To be included, the hazard ratio (HR) [95% CI] for the time to first relapse after first‐line immunosuppression had to be available, calculable, or provided by the authors.

Results

We gathered data from 919 NMO patients (232 RTX‐, 294 MMF‐, and 393 AZA‐treated patients). The risk of first relapse after first‐line immunosuppression was 1.55 [1.04, 2.31] (p = 0.03) for MMF compared with RTX, 1.42 [0.87, 2.30] (p = 0.16) for AZA compared with RTX, and 0.94 [0.58, 1.54] (p = 0.08) for MMF compared with AZA.

Interpretation

The findings suggest that RTX is more efficient than MMF as a first‐line therapy. Even if the results of our meta‐analysis cannot conclude that RTX has a better efficacy in delaying the first relapse than AZA, the observed effect difference between both treatments combined with the results of previous studies using as outcome the annualized relapse rate may be in favor of RTX.

Comparisons of clinical phenotype, radiological and laboratory features, and therapy of neuromyelitis optica spectrum disorder by regions: update and challenges

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory demyelinating disease of the central nervous system (CNS) associated with autoantibody (ab) to aquaporin-4 (AQP4). There is obvious variation between regions and countries in the epidemiology, clinical features and management in NMOSD. Based on published population-based observation and cohort studies, the different clinical pattern of NMOSD has been seen in several geographical regions and some of these patients with NMOSD-like features do not fully meet the current diagnostic criteria, which is needed to consider the value of recently revised diagnostic criteria. At present, all treatments applied in NMOSD have made great progress, however, these treatments failed in AQP4 ab negative and refractory patients. Therefore, it is necessary to turn into an innovative idea and to open a new era of NMOSD treatment to develop novel and diverse targets and effective therapeutic drugs in NMOSD and to conduct the trails in large clinical samples and case-control studies to confirm their therapeutic effects on NMOSD in the future, which still remain a challenge.

Efficacy of mycophenolate mofetil in the treatment of neuromyelitis optica spectrum disorders: An update systematic review and meta -analysis

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) is an autoimmune astrocyte disease that mainly affects the optic nerve and spinal cord resulting in blindness or paralysis. Mycophenolate mofetil (MMF) is one of the available immunotherapies with purported beneficial effects for patients with NMOSD. The present review aimed to conduct an update systematic review and meta-analysis for the efficacy of mycophenolate mofetil in the treatment of NMOSD and analyze main factors affecting the efficacy of mycophenolate mofetil.

METHODS

The following Medical Subject Heading (MeSH) and related entry terms are used to search English literature in PubMed, MEDLINE and CENTRAL databases, respectively. MeSH include: Neuromyelitis optic and Mycophenolic Acid; entry terms include: NMO Spectrum Disorder, NMO Spectrum Disorders, Neuromyelitis Optica (NMO) Spectrum Disorder, Neuromyelitis Optica Spectrum Disorders, Devic Neuromyelitis Optica, Neuromyelitis Optica, Devic, Devic's Disease, Devic Syndrome, Devic's Neuromyelitis Optica, Neuromyelitis Optica (NMO) Spectrum Disorders, Mycophenolate Mofetil, Mofetil, Mycophenolate, Mycophenolic Acid Morpholinoethyl Ester, Cellcept, Mycophenolate Sodium, Myfortic, Mycophenolate Mofetil Hydrochloride, Mofetil Hydrochloride, Mycophenolate, RS 61,443, RS-61,443, RS61443; (note: literature retrieval operators "AND" "OR" "NOT" are used to link MeSH with Entry Terms.) 30 studies were included in this systematic review and 14 studies were included in meta-analysis. The main efficacy indicators were the difference of the annualized relapse rate (ARR) between before and after mycophenolate mofetil treatments.

RESULTS

In 14 studies involving 930 patients (815 women, 115 men), the ARR were reduced by an average of -1.17 (95%CI, -1.28 to -1.07).

CONCLUSION

Our systematic review and update meta-analysis provide new evidences that mycophenolate mofetil can substantially reduce ARR ratio.

Longitudinal follow-up of serum biomarkers in patients with neuromyelitis optica spectrum disorder

BACKGROUND

Recently, several serum biomarkers have been proposed in Neuromyelitis Optica Spectrum Disorders (NMOSD) to monitor disease activity.

OBJECTIVE

The objective of the study is to evaluate the longitudinal clinical value of serum biomarkers in patients with NMOSD.

METHODS

We prospectively recruited consecutive NMOSD patients with anti-aquaporin-4 antibody and obtained serum samples at enrollment, after 6-12 months of follow-up (main period), and at attacks. Using single-molecule array assays, we evaluated longitudinal changes of serum neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and GFAP/NfL levels.

RESULTS

Overall, 64 patients (58 women) were enrolled (age: 51 years, disease duration: 6.7 years) and 133 samples were obtained. Among patients who did not develop new attacks during the main period (n = 62), serum levels of NfL, GFAP, and GFAP/NfL were significantly decreased over time in patients with attacks (<2 months) at enrollment (n = 14 (23%)), whereas serum NfL and GFAP levels gradually increased in the others (n = 48 (77%)). During the study, five (8%) patients developed new attacks; only serum GFAP levels increased consistently upon these events compared with baseline levels. To differentiate attacks from remissions, serum GFAP levels showed the largest area under the receiver operating characteristic curve (0.876, 95% confidence interval: 0.801-0.951).

CONCLUSION

Among NfL, GFAP, and GFAP/NfL, serum GFAP might be the most appropriate for monitoring NMOSD longitudinally, which warrants future confirming studies.

Neuromyelitis Optica Spectrum Disorder: Clinical Burden and Cost of Relapses and Disease-Related Care in US Clinical Practice

Introduction

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune condition characterized by unpredictable relapses that affect the optic nerves and spinal cord, which can lead to blindness, paralysis, and increased mortality rates. Evidence on the clinical and economic burden of NMOSD in the USA is currently lacking.

Methods

A retrospective, observational cohort study was conducted using data from the IQVIA PharMetrics Plus Healthcare Claims Database between January 1, 2012 and March 31, 2019. Adults (aged 18 years or more) with evidence of NMOSD and a matched group of comparison patients were identified. Outcomes, including NMOSD relapses, healthcare utilization, and healthcare expenditure (reported in 2018 US dollars), were evaluated during the follow-up period (maximum 6 years). Healthcare utilization and expenditure were assessed overall (all-cause) and during NMOSD relapses.

Results

The study included 1363 patients with NMOSD; the mean age was 44.9 years, and 75.3% were female. During the follow-up period (median 2.0 years), 47.7% of patients with NMOSD had one or more relapses, corresponding to an annualized relapse rate of 0.8 (95% confidence interval [CI] 0.7–0.9). When analyzing healthcare expenditure per patient, the mean annualized all-cause healthcare expenditure among patients with NMOSD was $60,599 (95% CI $52,112–66,716) compared with $8912 (95% CI $7084–10,727) among comparison patients, representing a difference of $51,687 (95% CI $43,820–58,664) attributable to NMOSD. The mean annualized total expenditure for NMOSD relapses was $10,070 (95% CI $7726–12,660) per patient, with hospital/inpatient care requiring more expenditure than ambulatory/outpatient care.

Conclusion

Findings of this large, retrospective, observational study indicate that relapses among patients with NMOSD are common in US clinical practice, leading to substantial healthcare utilization and expenditure. Therapies with the highest relapse risk reduction could lead to markedly lower relapse-associated healthcare utilization and clinical burden in patients with NMOSD.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-021-00253-4.

Neuromyelitis optica spectrum disorder (NMOSD) is a severely debilitating neurological disease that affects the nerves in the brain and spinal cord. People who have NMOSD may experience recurrent attacks, or relapses, that can cause blindness and disability. These relapses may lead to hospitalizations, doctor’s office visits, and pharmacy costs that are paid by health insurance plans. Overall, the cost of treating relapses in patients with NMOSD is substantial. Our study analyzed healthcare claims data from the USA. During a median follow-up time of 2.0 years, our study showed that 47.7% of patients with NMOSD experienced one or more relapses, resulting in hospital/inpatient admissions and ambulatory/outpatient treatments. In addition, the average healthcare cost among patients with NMOSD was $60,599 per year compared with $8912 per year for patients without NMOSD. This represents a difference of $51,687 per year, which can be attributed to NMOSD. Among patients with three or more relapses during the follow-up period, the average total healthcare cost was more than $83,000 per patient. Therefore, medicines that prevent relapses could lead to fewer relapse-associated hospitalizations and outpatient treatments for patients with NMOSD.