Nationwide prevalence and incidence study of neuromyelitis optica spectrum disorder in Denmark

Neuromyelitis optica spectrum disorder in China: Quality of life and medical care experience

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is considered to be the most common subset of CNS inflammatory demyelinating diseases in China. We aimed to systematically evaluate the impact of NMOSD on Chinese patients' quality of life (QoL), medical care experience, family wellness and social life.

METHODS

A cross-sectional survey was performed involving 210 mostly AQP4-IgG-positive NMOSD patients from 25 provinces across China. An established survey instrument specific for NMOSD developed by The Guthy-Jackson Charitable Foundation and the Multiple Sclerosis Quality of Life-54 scale were implemented. Pearson or Spearman Correlation analysis was performed to define the significant determinants of QoL.

RESULTS

More than 70% of the participants carried an initial diagnosis other than NMOSD, most of the patients were initially diagnosed with idiopathic optic neuritis (43.6%), multiple sclerosis (19.5%), gastrointestinal disorders (11.0%) and depression (10.0%). The average time elapsed between the first symptoms and accurate NMOSD diagnosis was 2.4 ± 4.9 years. Sixty-one percent of the participants reported NMOSD imposing a great negative impact on their life quality. NMOSD worsened both physical and emotional health (Short Form-36 physical health score: 37.9 ± 43.7, emotional health score: 44.8 ± 44.3). Visual impairment, pain, and bowel and bladder dysfunction were the greatest negative physical determinants of overall QoL. Worsened physical health was associated with diminished emotional health (r = 0.71, p < 0.001), and also with an interference in the ability to work (r = 0.41, p < 0.001). Only a small portion (3.3%) of the patients exhibited psychological resilience (with poor physical health but very robust emotional health). NMOSD significantly influenced the decision to have children in the study cohort, especially in the younger generation (r = -0.476, p < 0.001). Non-specific oral immunosuppressants were the most common preventive treatments, and only 13.9% received rituximab treatment. More than half (55.7%) of the patients reported dissatisfaction with current treatment options. A large proportion (88.1%) of the participants reported health insurance insufficient to pay all disease-related costs. Both concerns about treatment and about financial burden contributed to diminished QoL.

CONCLUSIONS

This investigation yields novel insights into the physical, emotional, and socioeconomic impact of NMOSD on Chinese patients, which may afford potentially modifiable aspects of personal or clinical care to improve the patients' QoL, as well as serve as baseline data to reflect how future standard treatments will change patients' life quality.

Genetic factors for susceptibility to and manifestations of neuromyelitis optica

OBJECTIVE

To identify genetic factors associated with susceptibility to and clinical features of neuromyelitis optica spectrum disorders (NMOSD).

METHODS

Genome-wide single nucleotide polymorphism (SNP) genotyping was conducted in 211 Japanese patients with NMOSD fulfilling the 2006 criteria with or without anti-aquaporin-4 (AQP4) antibody and 1,919 Japanese healthy controls (HCs). HLA-DRB1 and HLA-DPB1 alleles were genotyped in 184 NMOSD cases and 317 HCs. Multiple sclerosis (MS) risk alleles outside the major histocompatibility complex (MHC) region were tested in NMOSD and MS genetic burden (MSGB) scores were compared between HCs and NMOSD.

RESULTS

A SNP (rs1964995) in the MHC region was associated with NMOSD susceptibility (odds ratio (OR) = 2.33, P = 4.07 × 10^-11 ). HLA-DRB1*08:02 (OR = 2.86, P = 3.03 × 10^-4 ) and HLA-DRB1*16:02 (OR = 8.39, P = 1.92 × 10^-3 ) were risk alleles for NMOSD susceptibility whereas HLA-DRB1*09:01 was protective (OR = 0.27, P = 1.06 × 10^-5 ). Three MS risk variants were associated with susceptibility and MSGB scores were significantly higher in NMOSD than in HCs (P = 0.0095). A SNP in the KCNMA1 (potassium calcium-activated channel subfamily M alpha 1) gene was associated with disability score with genome-wide significance (rs1516512, P = 2.33 × 10^-8 ) and transverse myelitis (OR = 1.77, P = 0.011). KCNMA1 was immunohistochemically detected in the perivascular endfeet of astrocytes and its immunoreactivity was markedly diminished in active spinal cord lesions in NMOSD.

INTERPRETATION

Specific HLA-DRB1 alleles confer NMOSD susceptibility and KCNMA1 is associated with disability and transverse myelitis in NMOSD.

Mechanisms of sex hormones in autoimmunity: focus on EAE

Sex-related differences in the occurrence of autoimmune diseases is well documented, with females showing a greater propensity to develop these diseases than their male counterparts. Sex hormones, namely dihydrotestosterone and estrogens, have been shown to ameliorate the severity of inflammatory diseases. Immunologically, the beneficial effects of sex hormones have been ascribed to the suppression of effector lymphocyte responses accompanied by immune deviation from pro-inflammatory to anti-inflammatory cytokine production. In this review, we present our view of the mechanisms of sex hormones that contribute to their ability to suppress autoimmune responses with an emphasis on the pathogenesis of experimental autoimmune encephalomyelitis.

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.

Eculizumab in the treatment of neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disease of the CNS which is distinct from multiple sclerosis and typically presents with a relapsing course of optic neuritis, myelitis and midline brain inflammatory lesions. In at least two-thirds of cases, antibodies against the water channel AQP4 can be found, which lead to an antibody-mediated activation of the complement system with consecutive damage to neuronal structures. Eculizumab, a humanized monoclonal antibody against the terminal complement component 5, was shown to significantly reduce the risk of NMOSD relapse in a Phase III placebo-controlled trial. Based on this, eculizumab (Soliris^®) was the first drug to be formally approved for the treatment of anti-AQP4-antibody positive NMOSD in 2019.

Epidemiology of Neuromyelitis Optica Spectrum Disorder and Its Prevalence and Incidence Worldwide

Neuromyelitis optica spectrum disorder (NMOSD) is an uncommon inflammatory disease of the central nervous system, manifesting clinically as optic neuritis, myelitis, and certain brain and brainstem syndromes. Cases clinically diagnosed as NMOSD may include aquaporin 4 (AQP4)-antibody-seropositive autoimmune astrocytopathic disease, myelin oligodendrocyte glycoprotein (MOG)-antibody-seropositive inflammatory demyelinating disease, and double-seronegative disease. AQP4-antibody disease has a high female-to-male ratio (up to 9:1), and its mean age at onset of ~40 years is later than that seen in multiple sclerosis. For MOG-antibody disease, its gender ratio is closer to 1:1, and it is more common in children than in adults. Its clinical phenotypes differ but overlap with those of AQP4-antibody disease and include acute disseminated encephalomyelitis, brainstem and cerebral cortical encephalitis, as well as optic neuritis and myelitis. Double-seronegative disease requires further research and clarification. Population-based studies over the past two decades report the prevalence and incidence of NMOSD in different populations worldwide. One relevant finding is the varying prevalence observed in different racial groups. Consistently, the prevalence of NMOSD among Whites is ~1/100,000 population, with an annual incidence of <1/million population. Among East Asians, the prevalence is higher, at ~3.5/100,000 population, while the prevalence in Blacks may be up to 10/100,000 population. For MOG-antibody disease, hospital-based studies largely do not observe any significant racial preponderance so far. This disorder comprises a significant proportion of NMOSD cases that are AQP4-antibody-seronegative. A recent Dutch nationwide study reported the annual incidence of MOG-antibody disease as 1.6/million population (adult: 1.3/million, children: 3.1/million). Clinical and radiological differences between AQP4-antibody and MOG-antibody associated diseases have led to interest in the revisions of NMOSD definition and expanded stratification based on detection of a specific autoantibody biomarker. More population-based studies in different geographical regions and racial groups will be useful to further inform the prevalence and incidence of NMOSD and their antibody-specific subgroups. Accessibility to AQP4-antibody and MOG-antibody testing, which is limited in many centers, is a challenge to overcome. Environmental and genetic studies will be useful accompaniments to identify other potential pathogenetic factors and specific biomarkers in NMOSD.

Imaging of Neuromyelitis Optica Spectrum Disorders

Neuromyelitis optica (NMO) is a rare and chronic disabling autoimmune astrocytopathy of the central nervous system. Current advances regarding aquaporin-4 antibody function facilitate the understanding of clinical manifestations and imaging findings beyond optic neuritis and transverse myelitis. The current definition of NMO spectrum disorder (NMOSD) includes both aquaporin-4-IgG seropositive and seronegative patients who present with characteristic findings. This review will briefly summarize the pathophysiology and the latest NMOSD diagnostic criteria and focus on the NMOSD imaging findings and its differential diagnosis.

The Potential Immunoregulatory Roles of Vitamin D in Neuromyelitis Optica Spectrum Disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an autoantibody-mediated disease affecting the central nervous system (CNS). Its pathogenesis involves both innate and acquired immune reactions; specific antibody (Aquaporin-4 antibody) and inflammatory cells cause direct damage on lesion sites, while B cell-T cell interactions facilitate the demyelination. However, its etiology is still not fully understood. Vitamin D deficiency is present in numerous autoimmune diseases, including NMOSD. Evidence suggests that low vitamin D levels mayassociate with disease activity and relapse rate in NMOSD, indicating the participation in the pathogenesis of NMOSD. The immunoregulatory roles of vitamin D in both numerous autoimmune diseases and experimental autoimmune encephalomyelitis (EAE) models are increasingly recognized. Recent studies have revealed vitamin D modulation in cytokine production, immune cell development and differentiation, as well as antibody production. By enhancing an anti-inflammatory environment and suppressing the overactivated autoimmune process, vitamin D shows its potential immunoregulatory roles in NMOSD, which could possibly introduce a new therapy for NMOSD patients.

Epidemiology of pediatric multiple sclerosis, neuromyelitis optica, and optic neuritis in Taiwan

BACKGROUND AND OBJECTIVE

The epidemiology of pediatric acquired demyelinating disorders remains to be clarified in many parts of Asia. We carry out this study to depict the epidemiology of pediatric multiple sclerosis (MS), neuromyelitis optica (NMO), and optic neuritis (ON) in Taiwan.

METHODS

We conducted a retrospective nationwide population-based study using data from Taiwan's National Health Insurance Research Database. Prevalent cases of pediatric MS and NMO during 2001-2015, and incident cases of pediatric MS, NMO, and ON during 2003-2015 were identified. The demographic features and comorbidities were investigated.

RESULTS

We identified 403 MS, 42 NMO, and 1496 ON incident cases under the age of 20 during 2003-2015. The majority of pediatric MS (86.1%) and NMO (90.5%) patients were 10 years old or above. The incidence of MS and ON was relatively steady, while that of NMO increased prominently later during the study period. The average incidence of pediatric MS and NMO during 2011-2015 was 0.52 and 0.11 per 100,000 person-years, respectively. The female preponderance was evident for pediatric MS and NMO, and less so for pediatric ON. The most common autoimmune comorbidities for pediatric MS were thyrotoxicosis (1.0%) and systemic lupus erythematosus (0.7%).

CONCLUSION

The epidemiology of pediatric MS was largely stationary in Taiwan during 2001-2015, while the prevalence of pediatric NMO rose steeply during this period, probably reflecting better recognition of this clinical entity. Autoimmune comorbidities were uncommon for pediatric MS and NMO in Taiwan.

CNS inflammatory demyelinating disorders: MS, NMOSD and MOG antibody associated disease

Although Multiple Sclerosis is the most common central nervous system (CNS) inflammatory demyelinating disorder, other CNS inflammatory disorders should be included as diagnostic considerations. Neuromyelitis Optica Spectrum Disorder (NMOSD) and myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease are less common but share some clinical characteristics, such as optic neuritis and myelitis, which can make a specific diagnosis challenging. However, these disorders have distinctive and generally different clinical phenotypes, prognosis and management. It is imperative to distinguish each from one another, especially since the treatments (not discussed in this review) can be different. The advent of reliable testing for anti-aquaporin-4 for NMOSD and anti-MOG antibodies has helped significantly; however, diagnosis can remain challenging, especially in sero-negative cases. Clinical indicators are important to guide diagnostic work-up. Careful review of the history, neurological exam, imaging, and/or spinal fluid results are essential to making an accurate diagnosis. In this review, we will examine the clinical presentation, diagnosis, and natural history of these inflammatory CNS disorders.

Eculizumab in Aquaporin-4-Positive Neuromyelitis Optica Spectrum Disorder

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing, autoimmune, inflammatory disorder that typically affects the optic nerves and spinal cord. At least two thirds of cases are associated with aquaporin-4 antibodies (AQP4-IgG) and complement-mediated damage to the central nervous system. In a previous small, open-label study involving patients with AQP4-IgG-positive disease, eculizumab, a terminal complement inhibitor, was shown to reduce the frequency of relapse.

METHODS

In this randomized, double-blind, time-to-event trial, 143 adults were randomly assigned in a 2:1 ratio to receive either intravenous eculizumab (at a dose of 900 mg weekly for the first four doses starting on day 1, followed by 1200 mg every 2 weeks starting at week 4) or matched placebo. The continued use of stable-dose immunosuppressive therapy was permitted. The primary end point was the first adjudicated relapse. Secondary outcomes included the adjudicated annualized relapse rate, quality-of-life measures, and the score on the Expanded Disability Status Scale (EDSS), which ranges from 0 (no disability) to 10 (death).

RESULTS

The trial was stopped after 23 of the 24 prespecified adjudicated relapses, given the uncertainty in estimating when the final event would occur. The mean (±SD) annualized relapse rate in the 24 months before enrollment was 1.99±0.94; 76% of the patients continued to receive their previous immunosuppressive therapy during the trial. Adjudicated relapses occurred in 3 of 96 patients (3%) in the eculizumab group and 20 of 47 (43%) in the placebo group (hazard ratio, 0.06; 95% confidence interval [CI], 0.02 to 0.20; P<0.001). The adjudicated annualized relapse rate was 0.02 in the eculizumab group and 0.35 in the placebo group (rate ratio, 0.04; 95% CI, 0.01 to 0.15; P<0.001). The mean change in the EDSS score was -0.18 in the eculizumab group and 0.12 in the placebo group (least-squares mean difference, -0.29; 95% CI, -0.59 to 0.01). Upper respiratory tract infections and headaches were more common in the eculizumab group. There was one death from pulmonary empyema in the eculizumab group.

CONCLUSIONS

Among patients with AQP4-IgG-positive NMOSD, those who received eculizumab had a significantly lower risk of relapse than those who received placebo. There was no significant between-group difference in measures of disability progression. (Funded by Alexion Pharmaceuticals; PREVENT ClinicalTrials.gov number, NCT01892345; EudraCT number, 2013-001150-10.).

Epidemiology of neuromyelitis optica spectrum disorder in Denmark (1998-2008, 2007-2014)

Epidemiological studies of the uncommon disorder neuromyelitis optica spectrum disorder (NMOSD) may be difficult to interpret because of the evolving nature of diagnostic criteria, differences in the definition and accuracy of NMOSD diagnosis, the completeness of case ascertainment, and variability in assays for the disease-specific biomarker aquaporin-4 (AQP4)-IgG. A sub-group of patients with the clinical syndrome NMOSD lack detectable AQP4-IgG and in these cases an accurate diagnosis requires precise diagnostic algorithms and longitudinal follow-up. Consecutive sets of criteria for NMO/NMOSD have been introduced during the two last decades. Such criteria need validation in different populations. Detection of other autoantibodies, such as IgG specific for myelin oligodendrocyte glycoprotein or for glial fibrillary acidic protein in a sub-group of AQP4-IgG-negative NMOSD patients, has improved over the past decade and may lead to overlap of the clinical syndromes/phenotypes. This review begins by summarizing current knowledge on the widening clinical spectrum of NMOSD. Subsequently, we describe two epidemiological studies from Denmark carried out in two different decades (1998-2008 and 2007-2014) and comment on the differences in study design, patient ascertainment, and interpretation of results. These factors may explain some of the observed differences, reflecting the complexity and providing a clear example of this development.

Neuromyelitis optica spectrum disorder: Patient experience and quality of life

Objective

To gain insights into NMOSD disease impact, which may negatively affect QoL of patients, their families, and social network.

Methods

The current study used validated instruments to assess physical, emotional, and socioeconomic burden of NMOSD on QoL among 193 patients.

Results

A majority of patients reported an initial diagnosis of a disease other than NMOSD. Overall, two-thirds of patients reported NMOSD as having a strong negative impact on physical health (Short Form-36 [SF-36] score 27.1 ± 39.1), whereas emotional well-being was relatively unimpaired on average (SF-36 score 54.0 ± 44.9). A subset of patients reported having the highest category of emotional health despite worse physical health or financial burden, suggesting psychological resilience. Pain (r = 0.61) and bowel/bladder dysfunction (r = 0.41) imposed the greatest negative physical impact on overall QoL. In turn, ability to work correlated inversely with worsened health (r = −0.68). Increased pain, reduced sexual function, inability to work, and reduced QoL had greatest negative impacts on emotional well-being. Dissatisfaction with treatment options and economic burden correlated inversely with QoL.

Conclusions

Collectively, the current findings advance the understanding of physical, emotional, social, and financial tolls imposed by NMOSD. These insights offer potential ways to enhance QoL by managing pain, enhancing family and social networks, and facilitating active employment.

Incidence of pediatric neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease in Denmark 2008‒2018: A nationwide, population-based cohort study

BACKGROUND

The incidence of pediatric neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease have not been reported previously. Our aim was to estimate the incidence of pediatric NMOSD and the occurrence of anti-MOG antibody-associated disease in Denmark during 2008-18, and to evaluate the diagnostic usefulness of antibodies against MOG and aquaporin-4 (AQP4) in children <18 years.

METHODS

We undertook a nationwide, population-based, multicenter cohort study using data from the Danish National Patient Register, the Danish Multiple Sclerosis Registry, and laboratories providing anti-AQP4 and anti-MOG antibody analyses. Diagnoses were confirmed by review of the medical records, including blinded MRI review in most children with acute disseminated encephalomyelitis (ADEM).

RESULTS

In children with acquired demyelinating syndromes, anti-AQP4 antibodies were detected in 4% and anti-MOG antibodies in 18%, including in the two children with ADEM who relapsed. We identified four children with NMOSD, equivalent to an incidence of 0.031/100,000 (95% confidence interval = 0.011‒0.082). In anti-MOG antibody-positive children, 32% relapsed during follow-up.

CONCLUSIONS

Pediatric NMOSD and MOG antibody-associated disease are rare, but one-third of anti-MOG-positive children relapsed. In pediatric ADEM, only anti-MOG antibody-positive children relapsed, but the overall risk of relapse after pediatric ADEM was low.