Central nervous system neuroinflammatory disorders in Asian/Pacific regions

Results of a Survey on Diagnostic Procedures and Treatment Choices for Neuromyelitis Optica Spectrum Disorder in Korea: Beyond the Context of Current Clinical Guidelines

Background and Purpose

Neuromyelitis optica spectrum disorder (NMOSD) is a rare demyelinating disease of the central nervous system (CNS). We investigated the medical behaviors of experts in Korea when they are diagnosing and treating NMOSD.

Methods

An anonymous questionnaire on the diagnosis and treatment of NMOSD was distributed to experts in CNS demyelinating diseases.

Results

Most respondents used the 2015 diagnostic criteria for NMOSD and applied a cerebrospinal fluid examination, magnetic resonance imaging (MRI) of the brain and spine, and anti-aquaporin-4 antibody testing to all suspected cases of NMOSD. All respondents prescribed steroid pulse therapy as an first-line therapy in the acute phase of NMOSD, and 67% prescribed azathioprine for maintenance therapy in NMOSD. However, details regarding monitoring, the tapering period of oral steroids, second-line therapy use in refractory cases, management during pregnancy, and schedule of follow-up MRI differed according to the circumstances of individual patients. We analyzed the differences in response rates between two groups of respondents according to the annual number of NMOSD patients that they treated. The group that had been treating ≥10 NMOSD patients annually preferred rituximab more often as the second-line therapy (p=0.011) and had more experience with rituximab treatment (p=0.015) compared with the group that had been treating <10 NMOSD patients.

Conclusions

This study has revealed that NMOSD experts in Korea principally follow the available treatment guidelines. However, the differences in specific clinical practices applied to uncertain cases that have been revealed will need to be investigated further in order to formulate suitable recommendations.

BLK polymorphisms and expression level in neuromyelitis optica spectrum disorder

Aim

This study aimed to determine the correlation between B‐lymphoid tyrosine kinase (BLK) polymorphism, mRNA gene expression of BLK, and NMOSD in a Chinese Han population.

Background

B‐lymphoid tyrosine kinase gene expressed mainly in B cells plays a key role in various autoimmune disorders. However, no studies have investigated the association of BLK polymorphisms with neuromyelitis optica spectrum disorder (NMOSD).

Methods

Han Chinese population of 310 subjects were recruited to analyze three single nucleotide polymorphisms (rs13277113, rs4840568, and rs2248932) under allele, genotype, and haplotype frequencies, followed by clinical characteristics stratified analysis. Real‐time PCR was used to analyze mRNA expression levels of BLK in the peripheral blood mononuclear cells of 64 subjects.

Results

Patients with NMOSD showed lower frequencies of the minor allele G of rs2248932 than healthy controls (odds ratio (OR) =0.57, 95% confidence intervals (CI) 0.39–0.83, p = 0.003). The association between minor allele G of rs2248932 and reduced NMOSD susceptibility was found by applying genetic models of inheritance (codominant, dominant, and recessive) and haplotypes analysis. Subsequently, by stratification analysis for AQP4‐positivity, the minor allele G frequencies of rs2248932 in AQP4‐positive subgroup were significantly lower than in the healthy controls (OR =0.46, 95% CI 0.30–0.72, p = 0.001). Notably, the genotype GG of rs2248932 was more frequent in AQP4‐negative subgroup (n = 14) than in AQP4‐positive subgroup (n = 93) (p = 0.003, OR =0.05, 95% CI =0.01–0.57). BLK mRNA expression levels in the NMOSD patients (n = 36) were lower than in healthy controls (n = 28) (p < 0.05). However, the acute non‐treatment (n = 7), who were untreated patients in the acute phase from the NMOSD group, showed BLK mRNA expression levels 1.8‐fold higher than healthy controls (n = 8) (p < 0.05).

Conclusion

This study evaluated that the minor allele G of rs2248932 in BLK is associated with reduced susceptibility to NMOSD and protected the risk of AQP4‐positive. BLK mRNA expression in NMOSD was lower as compared to healthy controls while significantly increased in acute‐untreated patients.

Emerging Targeted Therapies for Neuromyelitis Optica Spectrum Disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune, inflammatory disorder of the central nervous system that typically presents with recurrent episodes of optic neuritis, longitudinally extensive myelitis, brainstem, diencephalic, and cerebral syndromes. Up to 80% of NMOSD patients have a circulating pathogenic autoantibody that targets the water channel aquaporin-4 (AQP4-IgG). The discovery of AQP4-IgG transformed our understanding of the pathogenesis of the disease and its possible treatment targets. Monoclonal antibodies targeting terminal complement (eculizumab), CD19 (inebilizumab), and the interleukin-6 receptor (satralizumab) have demonstrated efficacy in NMOSD attack prevention in recent phase 3 trials and have gained subsequent regulatory approval in the USA and other countries. We aim to review the evidence supporting the efficacy of these new drugs.

AQP4-IgG and MOG-IgG Related Optic Neuritis-Prevalence, Optical Coherence Tomography Findings, and Visual Outcomes: A Systematic Review and Meta-Analysis

Background: Optic neuritis (ON) is a cardinal manifestation of multiple sclerosis (MS), aquaporin-4 (AQP4)-IgG-, and myelin oligodendrocyte glycoprotein (MOG)-IgG-associated disease. However, the prevalence of AQP4-IgG seropositivity and MOG-IgG seropositivity in isolated ON is unclear, and studies comparing visual outcomes and optical coherence tomography (OCT)-derived structural retinal measures between MS-ON, AQP4-ON, and MOG-ON eyes are limited by small sample sizes. Objectives: (1) To assess the prevalence of AQP4-IgG and MOG-IgG seropositivity among patients presenting with isolated ON; (2) to compare visual outcomes and OCT measures between AQP4-ON, MOG-ON, and MS-ON eyes. Methods: In this systematic review and meta-analysis, a total of 65 eligible studies were identified by PubMed search. Statistical analyses were performed with random effects models. Results: In adults with isolated ON, AQP4-IgG seroprevalence was 4% in non-Asian and 27% in Asian populations, whereas MOG-IgG seroprevalence was 8 and 20%, respectively. In children, AQP4-IgG seroprevalence was 0.4% in non-Asian and 15% in Asian populations, whereas MOG-IgG seroprevalence was 47 and 31%, respectively. AQP4-ON eyes had lower peri-papillary retinal nerve fiber layer (pRNFL; -11.7 μm, 95% CI: -15.2 to -8.3 μm) and macular ganglion cell + inner plexiform layer (GCIPL; -9.0 μm, 95% CI: -12.5 to -5.4 μm) thicknesses compared with MS-ON eyes. Similarly, pRNFL (-11.2 μm, 95% CI: -21.5 to -0.9 μm) and GCIPL (-6.1 μm, 95% CI: -10.8 to -1.3 μm) thicknesses were lower in MOG-ON compared to MS-ON eyes, but did not differ between AQP4-ON and MOG-ON eyes (pRNFL: -1.9 μm, 95% CI: -9.1 to 5.4 μm; GCIPL: -2.6 μm, 95% CI: -8.9 to 3.8 μm). Visual outcomes were worse in AQP4-ON compared to both MOG-ON (mean logMAR difference: 0.60, 95% CI: 0.39 to 0.81) and MS-ON eyes (mean logMAR difference: 0.68, 95% CI: 0.40 to 0.96) but were similar in MOG-ON and MS-ON eyes (mean logMAR difference: 0.04, 95% CI: -0.05 to 0.14). Conclusions: AQP4-IgG- and MOG-IgG-associated disease are important diagnostic considerations in adults presenting with isolated ON, especially in Asian populations. Furthermore, MOG-IgG seroprevalence is especially high in pediatric isolated ON, in both non-Asian and Asian populations. Despite a similar severity of GCIPL and pRNFL thinning in AQP4-ON and MOG-ON, AQP4-ON is associated with markedly worse visual outcomes.

Incidence of neuromyelitis optica spectrum disorder (NMOSD) in China: A national population-based study

BACKGROUND

Neuromyelitis Optica Spectrum Disorder (NMOSD) is an inflammatory disease of the central nervous system with preferential involvement of the optic nerve and spinal cord. However, data on NMOSD incidences in China, a country encompassing 20% of the world's population and covering vast areas of Eastern Asia, are unknown.

METHODS

We conducted the first nationwide survey of NMOSD, based on the database of the National Hospital Quality Monitoring System (HQMS) of China, which covers all 1665 tertiary hospitals. The "Medical Record Homepage" of all patients were consistently collected via a standard protocol across each tertiary hospital. The primary outcome was the incidence of NMOSD, diagnosed according to the 2015 International Panel for Neuromyelitis Optica Diagnosis criteria and identified by ICD-10 code (G36•0). Burden of hospitalization, comorbidities, and death were also evaluated.

FINDINGS

We identified 33,489 hospital admissions for 17,416 NMOSD diagnosed patients from 2016 to 2018. 11,973 patients were newly diagnosed NMOSD. The age and sex adjusted incidence per 100,000 person years was 0•278 (95% confidence interval [CI], 0•273-0•283), with 0•075 (0•069-0•08) in child and 0•347 (0•34-0•353) in adult. The peak age of onset NMOSD is 45-65 years with an incidence 0•445/100,000 (95% CI, 0•433-0•457). The female to male ratio was 4•71 (p<0•001, 95% CI, 4•50-4•94). Geographical distribution of NMOSD is not related to the latitude gradient. Sjögren's syndrome (1,124/17,416, 6•5%) and systemic lupus erythematosus (387/17,416, 2•2%) are the most frequently autoimmune comorbidities. 106 adults and 4 children of the 17,416 NMOSD cohort died.

INTERPRETATION

The incidence of NMOSD in China per 100,000 person years was 0•278, with 0•075 in child and 0•347 in adult. The geographical distribution of NMOSD is not related to the latitude gradient.

FUNDING

National Science Foundation of China (91949208, 91642205, and 81830038); Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing.

Pediatric NMOSD: A Review and Position Statement on Approach to Work-Up and Diagnosis

Neuromyelitis Optica Spectrum Disorder (NMOSD) is an inflammatory demyelinating disease of the central nervous system (CNS) primarily affecting the optic nerves and spinal cord, but also involving other regions of the CNS including the area postrema, periaqueductal gray matter, and hypothalamus. Knowledge related to pediatric manifestations of NMOSD has grown in recent years, particularly in light of newer information regarding the importance of not only antibodies to aquaporin 4 (AQP4-IgG) but also myelin oligodendrocyte glycoprotein (MOG-IgG) in children manifesting clinically with this syndrome. In this review, we describe the current state of the knowledge related to clinical manifestations, diagnosis, and chronic therapies for children with NMOSD, with emphasis on literature that has been published in the last 5 years. Following the review, we propose recommendations for the assessment/follow up clinical care, and treatment of this population.

Changing patterns of multiple sclerosis in Korea: Toward a more baseline MRI lesions and intrathecal humoral immune responses

BACKGROUND

The environmental risks of multiple sclerosis (MS), including adolescent obesity and vitamin D deficiency, are increasing in Korea. We aimed to determine whether the patterns and/or severity of MS in Korea can change according to the year of birth or disease onset.

METHODS

Two hundred and sixty-six patients with adult-onset MS, including 164 with an available baseline magnetic resonance imaging (MRI), were retrospectively included from 17 nationwide referral hospitals in Korea. The demographics, MRI T2 lesion burden at disease onset, cerebrospinal fluid markers, and prognosis were assessed.

RESULTS

The birth year, time from disease onset to first MRI, and female sex were associated with a higher number of baseline MRI T2 lesions. The birth year was also associated with the presence of oligoclonal band in the cerebrospinal fluid and high immunoglobin G index. An increased female/male ratio was observed among those with a more recent year of birth and/or disease onset.

CONCLUSIONS

In Korea, the disease pattern of adult-onset MS may be changing toward a more baseline T2 MRI lesions, intrathecal humoral immune responses, and also higher female ratio.

A randomized placebo-controlled trial of delayed-release dimethyl fumarate in patients with relapsing-remitting multiple sclerosis from East Asia and other countries

Background

Delayed-release dimethyl fumarate (DMF) has demonstrated efficacy and a favorable benefit-risk profile in phase 2 and 3 studies that enrolled predominantly white patients with relapsing-remitting multiple sclerosis (RRMS). In this study (APEX, Part I), we evaluated the efficacy/safety outcomes of DMF in a predominantly East Asian population of patients with RRMS.

Methods

In this 24-week, randomized, double-blind, placebo-controlled phase 3 study, 225 patients, 142 of which were East Asian (63.4%), were enrolled: Japan (n = 114), South Korea (n = 20), Taiwan (n = 8), the Czech Republic (n = 42), and Poland (n = 40). Key exclusion criteria included diagnosis of neuromyelitis optica spectrum disorder. Stratified by country, patients were randomized 1:1 to receive DMF 240 mg twice daily or placebo. Clinical assessments, including neurological examination and EDSS scoring, were conducted at baseline and at weeks 12 and 24.

Results

A total of 213 patients (95.1%) completed the study. From weeks 12 – 24, the total number of new gadolinium-enhancing (Gd⁺) lesions was reduced by 84% (p < 0.0001) in DMF compared with placebo. For the secondary endpoint, from baseline to week 24, the total number of new Gd⁺ lesions was reduced by 75% and the mean number of new/newly enlarging T2 hyperintense lesions was reduced by 63% (both p < 0.0001). Flushing and flushing-related symptoms, and gastrointestinal events were adverse events related to DMF treatment. Efficacy and safety results in the Japanese subgroup and the East Asian subgroup (which included patients from Japan, Taiwan, and South Korea) were consistent with the overall study population.

Conclusion

The strong efficacy and favorable benefit-risk profile of DMF extends to Japanese, and more broadly, East Asian patients with RRMS.

Trial registration

This trial is registered on ClinicalTrials.gov (identifier: NCT01838668), April 20, 2013 (retrospectively registered). The registration can be found at the following URL: https://clinicaltrials.gov/ct2/show/NCT01838668

Electronic supplementary material

The online version of this article (10.1186/s12883-018-1220-3) contains supplementary material, which is available to authorized users.

Association of GTF2IRD1-GTF2I polymorphisms with neuromyelitis optica spectrum disorders in Han Chinese patients

Variants at the GTF2I repeat domain containing 1 (GTF2IRD1)–GTF2I locus are associated with primary Sjögren’s syndrome, systemic lupus erythematosus, and rheumatoid arthritis. Numerous studies have indicated that this susceptibility locus is shared by multiple autoimmune diseases. However, until now there were no studies of the correlation between GTF2IRD1–GTF2I polymorphisms and neuromyelitis optica spectrum disorders (NMOSD). This case control study assessed this association by recruiting 305 participants with neuromyelitis optica spectrum disorders and 487 healthy controls at the Department of Neurology, from September 2014 to April 2017. Peripheral blood was collected, DNA extracteds and the genetic association between GTF2IRD1–GTF2I polymorphisms and neuromyelitis optica spectrum disorders in the Chinese Han population was analyzed by genotyping. We found that the T allele of rs117026326 was associated with an increased risk of neuromyelitis optica spectrum disorders (odds ratio (OR) = 1.364, 95% confidence interval (CI) 1.019–1.828; P = 0.037). This association persisted after stratification analysis for aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) positivity (OR = 1.397, 95% CI 1.021–1.912; P = 0.036) and stratification according to coexisting autoimmune diseases (OR = 1.446, 95% CI 1.072–1.952; P = 0.015). Furthermore, the CC genotype of rs73366469 was frequent in AQP4-IgG-seropositive patients (OR = 3.15, 95% CI 1.183–8.393, P = 0.022). In conclusion, the T allele of rs117026326 was associated with susceptibility to neuromyelitis optica spectrum disorders, and the CC genotype of rs73366469 conferred susceptibility to AQP4-IgG-seropositivity in Han Chinese patients. The protocol was approved by the Ethics Committee of West China Hospital of Sichuan University, China (approval number: 2016-31) on March 2, 2016.

Racial differences in neuromyelitis optica spectrum disorder

OBJECTIVE

We aimed to evaluate racial differences in the clinical features of neuromyelitis optica spectrum disorder.

METHODS

This retrospective review included 603 patients (304 Asian, 207 Caucasian, and 92 Afro-American/Afro-European), who were seropositive for anti-aquaporin-4 antibody, from 6 centers in Denmark, Germany, South Korea, United Kingdom, United States, and Thailand.

RESULTS

Median disease duration at last follow-up was 8 years (range 0.3-38.4 years). Asian and Afro-American/Afro-European patients had a younger onset age than Caucasian patients (mean 36, 33, and 44 years, respectively; p < 0.001). During the disease course, Caucasian patients (23%) had a lower incidence of brain/brainstem involvement than Asian (42%) and Afro-American/Afro-European patients (38%) (p < 0.001). Severe attacks (visual acuity ≤0.1 in at least one eye or Expanded Disability Status Scale score ≥6.0 at nadir) at onset occurred more frequently in Afro-American/Afro-European (58%) than in Asian (46%) and Caucasian (38%) patients (p = 0.005). In the multivariable analysis, older age at onset, higher number of attacks before and after immunosuppressive treatment, but not race, were independent predictors of severe motor disabilities at last follow-up.

CONCLUSION

A review of a large international cohort revealed that race affected the clinical phenotype, age at onset, and severity of attacks, but the overall outcome was most dependent on early and effective immunosuppressive treatment.

72-Week Safety and Tolerability of Dimethyl Fumarate in Japanese Patients with Relapsing-remitting Multiple Sclerosis: Analysis of the Randomised, Double Blind, Placebo-Controlled, Phase III APEX Study and its Open-Label Extension

Introduction

The long-term safety of dimethyl fumarate (DMF) in patients with relapsing-remitting multiple sclerosis (RRMS) has been studied in mainly Caucasian patients. The present interim analysis aimed to evaluate the 72-week safety of DMF in Japanese patients with RRMS.

Methods

Safety data of Japanese subjects enrolled in the 24-week randomised, double-blind, placebo-controlled APEX study (Part I) and its following open-label extension (Part II) were analysed at 72 weeks from the beginning of Part I. In Part I, subjects were randomised to DMF treatment or matching placebo while all subjects received DMF treatment during Part II. Adverse events (AEs) reported throughout the study period were recorded.

Results

Overall, 109 Japanese subjects completed 72 weeks of treatment. The incidence of AEs and serious AEs was 95% and 19%, respectively, in the DMF group compared with 84% and 18%, respectively, in the placebo group at 24 weeks. Common AEs (at least 5%) reported with treatment included nasopharyngitis, flushing, hot flush, gastrointestinal events, pruritus, rash, headache, increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST). AEs led to discontinuation of DMF in 5% of patients and included MS relapse, flushing, abdominal pain, liver disorder and increased ALT/AST. After an initial decrease from baseline of 17% in the DMF group at week 24, the mean lymphocyte counts stabilised and were maintained until week 72. No opportunistic/serious infections nor malignancies were reported with DMF treatment. The incidences of AEs, serious AEs, and discontinuation due to AEs were similar between the DMF and the placebo groups.

Conclusion

The 72-week safety profile of DMF in Japanese patients with RRMS was consistent with previous studies that enrolled mostly Caucasian patients, with a lower incidence of flushing and related symptoms and a lower reduction in the lymphocyte count compared with previous reports.

Trial Registration

ClinicalTrials.gov identifier NCT01838668.

Funding

Biogen Japan Ltd.

Electronic supplementary material

The online version of this article (10.1007/s12325-018-0788-8) contains supplementary material, which is available to authorized users.

Multiple sclerosis and neuromyelitis optica spectrum disorders in Malaysia: A comparison in different ethnic groups

We performed a retrospective observational analytical study looking at the frequencies and characteristics of multiple sclerosis(MS) and neuromyelitis optica spectrum disorders(NMOSD) in consecutive patients with idiopathic inflammatory demyelinating disease (IIDDs) attending three centers (2009-2017). Of 523 patients with IIDDs, there were 173 patients with NMOSD and 230 patients with MS. The percentage of NMOSD: IIDDs was 33%. The percentage of NMOSD:Total MS and NMOSD cohort was 43%. Of 141 seropositive NMOSD patients, 134(95%) were from the three main ethnic groups. The percentage of seropositive NMOSD to IIDDs and to combined MS and NMOSD was 26.9% and 35% respectively. Ratios of MS to NMOSD were nearly equal at 1.3 to 1.0, reinforcing the high ratio of NMOSD to MS in Asia. Nearly half of the Chinese cohort were seropositive ie; 71/141 (50%) with the remainder being Malays; 56/141 (39.7%) and Indians; 7/141 (5%). Amongst the other indigenous groups seropositivity was seen in 2 each of Iban, Bajau, Kadazan descent as well as one of Bidayuh origin. Comparatively, seropositivity in NMOSD is commoner amongst the Chinese compared to the Malays (p ≤ 0.005) and Indians, p ≤ 0.05 with ratios as high as 10:1. In the MS group of 230 subjects, 123(53.5%) were Malays (ratio of MS:NMOSD of 2:1), 41(17.8%) were Chinese, (ratio of MS:NMOSD of 0.5:1.0) and 54 (23.5%)were Indians (ratios of MS:NMOSD of 5:1 amongst the Indians). The remainder from East Malaysia were made up of 2 each of Kadazans, Ibans and Bajaus including 3 each of Bidayuh and Eurasian descent. Comparatively, in the NMOSD and MS cohorts a female preponderance was noted more so amongst Chinese NMOSD patients, with rare familial occurrence in both but more in Malay MS/NMOSD patients. This study also highlighted some of the inter-ethnic differences in presentation of MS and NMOSD amongst the 3 main ethnic races in Malaysia and confirms indigenous races having MS/NMOSD which needs further research. It also reviewed current literature on similar inter-ethnic differences world wide. To conclude, MS and NMOSD are the commonest demyelinating diseases seen in Malaysia with interesting inter-ethnic differences and similarities.

Short segment myelitis as a first manifestation of neuromyelitis optica spectrum disorders

BACKGROUND

Some patients with neuromyelitis optica spectrum disorders (NMOSD) present with spinal cord lesions extending fewer than three vertebral segments (short transverse myelitis, STM), hindering an early diagnosis.

OBJECTIVE

We investigated the frequency and imaging characteristics of STM lesions in patients presenting with myelitis as an initial manifestation of NMOSD.

METHODS

Patients seen at three referral hospitals in Korea between June 2005 and March 2015 who met the following inclusion criteria were recruited for review: seropositivity for aquaporin-4 antibody, initial presentation with myelitis and spinal cord magnetic resonance imaging (MRI) performed within 1 month of initial myelitis onset.

RESULTS

Of the 76 enrolled patients, 65 (85.5%) collectively had 69 longitudinally extensive transverse myelitis lesions, while the remaining 11 (14.5%) had a total of 15 STM lesions. Of the 15 STM lesions, 5 spanned 2.5 vertebral segments, 6 were continuous over two segments, 3 showed a length of 1.5 segments and 1 was confined to a single segment. On axial imaging, all of the STM lesions involved the central grey matter.

CONCLUSION

These MRI findings suggested that STM does not preclude the possibility of an NMOSD diagnosis.