Epidemiology of NMOSD in Sweden from 1987 to 2013: A nationwide population-based study

The value of CSF diagnostic and prognostic biomarkers in NMOSD and MOGAD in real-life use

BACKGROUND

Diagnosing neuromyelitis optica spectrum disorder (NMOSD) may be challenging owing to overlapping clinical features with multiple sclerosis (MS) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), particularly in AQP4-IgG seronegative NMOSD patients. We evaluated cerebrospinal fluid (CSF) biomarkers, specifically glial fibrillary acidic protein (GFAP) and albumin quotient (QAlb), to improve diagnostic accuracy in NMOSD.

METHODS

In this retrospective study, we analyzed CSF samples for biomarkers GFAP, QAlb, neurofilament light, and total-Tau, from patients with AQP4-NMOSD, DNNMOSD, MOGAD, and MS in the Region Västra Götaland, Sweden. Receiver operating characteristic (ROC) analysis with calculation of the area under the curve (AUC) was used to identify optimal cut-off levels for discriminating AQP4-NMOSD from the other groups. Logistic regression models assessed the diagnostic power of GFAP and QAlb combined.

RESULTS

Patients with AQP4-NMOSD (N = 19) had significantly higher CSF GFAP levels than the others: median 2470 ng/L vs 330 ng/L (p < 0.001). The GFAP cutoff >715 ng/L gave a sensitivity of 81 % and specificity of 92 %. Combining GFAP and QAlb further increased the diagnostic accuracy (AUC = 0.96). MOGAD patients (N = 29) had the highest CSF lymphocyte counts, with elevated lymphocyte counts correlating with polyphasic MOGAD (R = 0.63; p = 0.016).

CONCLUSION

CSF GFAP is a valuable biomarker for distinguishing AQP4-NMOSD from other demyelinating diseases: Combining GFAP with QAlb enhances diagnostic precision.

The epidemiology and clinical presentation of seropositive neuromyelitis optica spectrum disorder in a US population

OBJECTIVE

To define the epidemiology and clinical presentation of seropositive neuromyelitis optica spectrum disorder (NMOSD) in a large US health system.

METHODS

We completed a retrospective observational study of adult patients in the University of Colorado Health System from 1 January 2011 to 31 December 2020, using Health Data Compass (HDC), a data warehouse that combines electronic health information with claims and public health data in Colorado. We screened HDC for patients with either (1) an abnormal aquaporin-4 IgG test or (2) any G36 ICD-10 code. We extracted key clinical elements by chart review and confirmed diagnosis by the 2015 International Panel for NMO Diagnosis criteria. Annual incidence and prevalence rates were calculated.

RESULTS

Our population consisted of 2,475,591 individuals contributing 11,103,522.72 person-years of observation. In total, 115 seropositive NMOSD patients were identified. The average yearly incidence was 0.22 per 100,000 person-years. Age and sex-adjusted prevalence (per 100,000) was 4.33, and highest among those identifying as Asian or Pacific Islander (17.72), and Black (14.74), as separately by Hispanic ethnicity (8.02). Prevalence was higher in women (6.20:1 female:male ratio). Transverse myelitis (45%) and optic neuritis (43%) were the most common presenting clinical syndromes. In total, 6% of initial presentations were characterized by short-segment transverse myelitis without other features.

INTERPRETATION

Seropositive NMOSD incidence is higher in our cohort than many contemporary studies. Women and those identifying as Asian or Pacific Islander, Black, and Hispanic shoulder the highest burden of disease. Clinical onset with short-segment myelitis underscores the need for serum aquaporin-4 IgG testing in acute myelitis presentations.

The prevalence, incidence, and clinical assessment of neuromyelitis optica spectrum disorder in patients with demyelinating diseases

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is characterised by recurrent attacks of optic neuritis and transverse myelitis. The purpose of this work was to identify the incidence and prevalence of NMOSD and its clinical characteristics in the population treated for demyelinating diseases in Western Mexico.

MATERIAL AND METHOD

A descriptive, retrospective study was carried out in the Department of Neurology, at the Sub-specialty Medical Unit, Specialties Hospital (known by its Spanish abbreviation UMAE-HE), of the National Western Medical Center (CMNO), Mexican Institute of Social Security (IMSS). A review of the electronic files for all patients with a diagnosis of NMOSD in 2019, was carried out in the State of Jalisco, Mexico.

RESULTS

Fifty-eight patients with NMOSD were included in the study. The incidence was 0.71/100 000 (CI 0.60-0.85) and the prevalence was 1.09/100 000 (CI 0.84-1.42). There were 79.3% women, and 20.6% were men (P = .01). All (100%) patients presented with anti-aquaporin-4 immunoglobulin G, and 89.6% showed seropositivity for anti-aquaporin-4 (CI 82.6-94.9). Magnetic resonance imaging was performed on 100% of patients, where 34.4% were normal, and 65.5% (38) abnormal, presenting with non-specific subcortical lesions (P = 0.04). The initial clinical presentation was optic neuritis (ON) in 58.6%; where 31.0% was bilateral ON, 20.7% was left ON, and 6.9% were right ON; transverse myelitis in 26.0%, area postrema syndrome (APS) in 10.3%, among others.

CONCLUSIONS

The incidence of NMOSD exceeds 0.71/100 000, the prevalence is low at 1.09/100 000, and NMOSD is predominantly found in women.

Sex ratio and age of onset in AQP4 antibody-associated NMOSD: a review and meta-analysis

BACKGROUND

Aquaporin-4 (AQP4) antibody-associated neuromyelitis optica spectrum disorder (NMOSD) is an antibody-mediated inflammatory disease of the central nervous system. We have undertaken a systematic review and meta-analysis to ascertain the sex ratio and mean age of onset for AQP4 antibody associated NMOSD. We have also explored factors that impact on these demographic data.

METHODS

A systematic search of databases was conducted according to the PRISMA guidelines. Articles reporting sex distribution and age of onset for AQP4 antibody-associated NMSOD were reviewed. An initially inclusive approach involving exploration with regression meta-analysis was followed by an analysis of just AQP4 antibody positive cases.

RESULTS

A total of 528 articles were screened to yield 89 articles covering 19,415 individuals from 88 population samples. The female:male sex ratio was significantly influenced by the proportion of AQP4 antibody positive cases in the samples studied (p < 0.001). For AQP4 antibody-positive cases the overall estimate of the sex ratio was 8.89 (95% CI 7.78-10.15). For paediatric populations the estimate was 5.68 (95% CI 4.01-8.03) and for late-onset cases, it was 5.48 (95% CI 4.10-7.33). The mean age of onset was significantly associated with the mean life expectancy of the population sampled (p < 0.001). The mean age of onset for AQP4 antibody-positive cases in long-lived populations was 41.7 years versus 33.3 years in the remainder.

CONCLUSIONS

The female:male sex ratio and the mean age of onset of AQP4 antibody-associated NMOSD are significantly higher than MS. The sex ratio increases with the proportion of cases that are positive for AQP4 antibodies and the mean age of onset increases with population life expectancy.

Characterizing mortality in patients with AQP4-Ab+ neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder is an autoimmune disease, causing severe disability due to relapses, but recent mortality data are limited. Among 396 patients seropositive for anti-aquaporin-4 antibody from 2014 to 2020 in the United Kingdom, 39 deaths occurred: 19 (48.7%) were unrelated to disease; 14 (35.9%) were severe disability- or relapse-related; and 4 (10.3%) were attributed to malignancy/infection. Mean annual mortality was 1.92% versus 0.63% in the matched population. The standardized mortality ratio was 3.04 (95% confidence interval 1.67-5.30) with 1.29% excess mortality per year in patients. Median Expanded Disability Status Scale before death was 7.0. Results highlight the importance of preventing relapses that drive disability.

Therapeutic plasma exchange for neuromyelitis optica attacks: Evidence and challenges from a real-world cohort from Brazil

Therapeutic plasma exchange (TPE) can improve disability recovery after neuromyelitis optica spectrum disease (NMOSD) attacks, but its effectiveness and safety in Latin-American patients with access barriers and diverse ethnicity is underexplored. We carried out a retrospective cohort study with NMOSD patients that underwent TPE. 84 NMOSD attacks in 68 patients were evaluated. Despite a median 25-day delay from symptom onset to TPE, 65,5% of patients showed significant improvement. Adverse events occurred in 39% of patients, usually transitory and with no fatalities.

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.

Nationwide analysis of neuromyelitis optica in systemic lupus erythematosus and Sjogren's syndrome

OBJECTIVE

Neuromyelitis optica (NMO), also known as Devic's disease, is a rare inflammatory demyelinating disorder causing myelitis and optic neuritis. While there have been reports of systemic lupus erythematosus (SLE) and primary Sjogren's syndrome (SS) occurring with NMO, a formal association is not established. We aimed to investigate the occurrence of NMO in SLE and SS patients and study the clinical characteristics and outcomes of NMO and SLE/SS hospitalizations utilizing the national inpatient sample (NIS) database.

METHODS

The NIS database from 2016 to 2019 was used to extract data. Adult hospitalizations with the principal or secondary diagnosis of NMO were included. We classified NMO patients with and without concomitant diagnosis of SLE or Sjogren's syndrome. We evaluated and compared the clinical characteristics and outcomes of NMO hospitalizations with and without SLE or Sjogren's syndrome. STATA17 was used for data analysis. We also calculated the odds ratio of NMO in SLE and Sjogren's syndrome.

RESULTS

There were a total of 16,360 adult hospitalizations with the principal or secondary discharge diagnosis of NMO. Among all NMO hospitalizations, 1425 (8.71%) had the primary or secondary diagnosis of SLE or SS. The odds of NMO in SLE and Sjogren's syndrome were noted to be 12.29 and 5.56, respectively. NMO with SLE/SS group had higher proportion of females (89.82% vs 79%, P value < 0.001), African Americans (56.63% vs 38.28, P value < 0.001), and Asians (5.73% vs 3.25, P value 0.04). The Charlson comorbidity index was higher for NMO-SLE/SS overlap (2.44 vs 1.28, P value < 0.001). There was no significant difference in overall mortality rates of both groups (2.11% vs 1.2%, P value 0.197). There were significantly higher reported seizures (14.73% vs 6.05, P value < 0.001) and paraplegia (21.75% vs 13.93%, P value < 0.001) in NMO-SLE/SS patients. These patients also had a longer length of stay in comparison to the reference group (7 vs 5 days, P value < 0.001) as well as higher total charges.

CONCLUSIONS

NMO patients had a 12-fold higher risk of SLE and 5-fold higher risk of Sjogren's disease when compared to general population. Patients with overlap of NMO and SLE or Sjogren's were predominantly women and were more likely to be African-American. Co-existence of these autoimmune disorders was associated with poor prognosis in terms of higher morbidity for patients and increased health care burden. Key Points • NMO is a rare autoimmune disease seen predominantly in women in the middle age group with low overall mortality. • SLE and Sjogren's have increased odds of NMO in comparison to general population. • NMO patients have high rates of several complications such as paraplegia, quadriplegia, seizures, blindness, sepsis, and respiratory failure with even higher rates of seizures and paraplegia in those with concomitant SLE or Sjogren's.

A comprehensive review of the advances in neuromyelitis optica spectrum disorder

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

Mortality of neuromyelitis optica spectrum disorder patients in an Argentinean population: A study from the RelevarEM registry

We aimed to evaluate mortality and causes of death among Argentinean neuromyelitis optica spectrum disorder (NMOSD) patients and identify predictors of death. Retrospective study included 158 NMOSD patients and 11 (7%) patients died after 11 years of follow-up for a total exposure time of 53,345 days with an overall incidence density of 2.06 × 10.000 patients/day (95% CI 1.75-2.68). Extensive cervical myelitis with respiratory failure (45%) was the most frequent cause of death. Older age (HR = 2.05, p = 0.002) and higher disability score (HR = 2.30, p < 0.001) at disease onset were independent predictors of death. We found an 11-year mortality rate of 7% in Argentinean NMOSD patients.

Research progress on pathogenesis and clinical treatment of neuromyelitis optica spectrum disorders (NMOSDs)

Neuromyelitis optica spectrum disorders (NMOSDs) are characteristically referred to as various central nervous system (CNS)-based inflammatory and astrocytopathic disorders, often manifested by the axonal damage and immune-mediated demyelination targeting optic nerves and the spinal cord. This review article presents a detailed view of the etiology, pathogenesis, and prescribed treatment options for NMOSD therapy. Initially, we present the epidemiology of NMOSDs, highlighting the geographical and ethnical differences in the incidence and prevalence rates of NMOSDs. Further, the etiology and pathogenesis of NMOSDs are emphasized, providing discussions relevant to various genetic, environmental, and immune-related factors. Finally, the applied treatment strategies for curing NMOSD are discussed, exploring the perspectives for developing emergent innovative treatment strategies.

Clinical and radiological profile of neuromyelitis optica spectrum disorders in a Pakistani cohort

BACKGROUND

The clinical and radiological characteristics of neuromyelitis optica spectrum disorder (NMOSD) from Pakistan is unknown. Our study aimed to describe the clinical and radiological features of NMOSD patients presenting to a Pakistani tertiary care center.

MATERIALS AND METHODS

This retrospective, observational study was conducted at the Neurology Department, Pakistan Institute of Medical Sciences between January 2017 and September 2021 (56 months). The study included patients diagnosed with neuromyelitis optica spectrum disorder (NMOSD) according to the 2015 International Panel for NMO Diagnosis (IPND) criteria, with the exclusion of patients under 12 years of age and those who tested positive for Myelin oligodendrocyte glycoprotein (MOG) IgG antibody. The patients were divided into two groups based on clinical presentation and the presence of NMO-IgG antibodies: NMO-IgG positive NMO (Seropositive NMO) and NMO-IgG negative (Seronegative NMO). The clinical features of NMOSD were recorded, and data was analyzed using SPSS version 26.0.

RESULTS

Among 204 patients with suspected demyelination, multiple sclerosis was diagnosed in 100 individuals (49.02%), while acute disseminated encephalomyelitis (ADEM), clinically isolated syndrome (CIS), and neuromyelitis optica (NMO) were found in 5 patients each (2.45%, 2.45%, and 17.65%, respectively). Out of 36 patients with NMO, 32 (88.89%) tested positive for NMO-Ab, while the remaining 4 (11.11%) were seronegative for both NMO and anti-MOG Abs. The mean age of NMO-positive patients who tested positive for NMO antibodies was 31.03±10.12 years, compared to 27.95±2.5 years for NMO-negative patients, though this difference was not statistically significant (p>0.05). Females were more commonly affected by NMO, accounting for 72.2% of the NMO-positive group, and there was a significant difference in clinical phenotypes between the two groups (p<0.05). The NMO-positive group predominantly had relapsing NMO presentation (75%), and 72.8% of these patients showed longitudinally extensive transverse myelitis on the MRI spine. Azathioprine was the most frequently administered treatment for positive NMO patients (69.44%), followed by rituximab and MMF. The follow-up period for the study participants lasted 24 months.

CONCLUSION

This is the first study on NMOSD cases in Pakistan. According to the present study, NMOSD is most prevalent among women in their forties. Relapsing NMO was the most common form of presentation. 89% of patients had antibodies against AQP4. 72.8% of patients suffered from LETM during the course of their disease. There are some features of our NMOSD cases that appear comparable with those around the world, despite some limitations in testing and access to care. It is clear that the clinical and radiological spectrums of patients with NMO and NMOSD in this cohort are similar. It is reasonable to suspect NMO if demyelinating episodes are not characteristic of MS.

The Pathological Activation of Microglia Is Modulated by Sexually Dimorphic Pathways

Microglia are the primary immunocompetent cells of the central nervous system (CNS). Their ability to survey, assess and respond to perturbations in their local environment is critical in their role of maintaining CNS homeostasis in health and disease. Microglia also have the capability of functioning in a heterogeneous manner depending on the nature of their local cues, as they can become activated on a spectrum from pro-inflammatory neurotoxic responses to anti-inflammatory protective responses. This review seeks to define the developmental and environmental cues that support microglial polarization towards these phenotypes, as well as discuss sexually dimorphic factors that can influence this process. Further, we describe a variety of CNS disorders including autoimmune disease, infection, and cancer that demonstrate disparities in disease severity or diagnosis rates between males and females, and posit that microglial sexual dimorphism underlies these differences. Understanding the mechanism behind differential CNS disease outcomes between men and women is crucial in the development of more effective targeted therapies.

A national case-control study investigating demographic and environmental factors associated with NMOSD

BACKGROUND

Risk factors for aquaporin-4 (AQP4+) antibody neuromyelitis optica spectrum disorder (NMOSD) are not well-established.

OBJECTIVE

To investigate demographic and environmental factors associated with NMOSD using a validated questionnaire and case-control design.

METHODS

We enrolled patients with AQP4 + NMOSD through six Canadian Multiple Sclerosis Clinics. Participants completed the validated Environmental Risk Factors in Multiple Sclerosis Study (EnvIMS) questionnaire. Their responses were compared to those of 956 unaffected controls from the Canadian arm of EnvIMS. We calculated odds ratios (ORs) for the association between each variable and NMOSD using logistic regression and Firth's procedure for rare events.

RESULTS

In 122 participants (87.7% female) with NMOSD, odds of NMOSD in East Asian and Black participants were ⩾8 times that observed in White participants. Birthplace outside Canada was associated with an increased risk of NMOSD (OR = 5.5, 95% confidence interval (CI) = 3.6-8.3) as were concomitant autoimmune diseases (OR = 2.7, 95% CI = 1.4-5.0). No association was observed with reproductive history or age at menarche.

CONCLUSION

In this case-control study, risk of NMOSD in East Asian and Black versus White individuals was greater than that observed in many previous studies. Despite the preponderance of affected women, we did not observe any association with hormonal factors such as reproductive history or age at menarche.

Worldwide prevalence of neuromyelitis optica spectrum disorder (NMOSD) and neuromyelitis optica (NMO): a systematic review and meta-analysis

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a progressive demyelinating disease of the central nervous system that has overlapping symptoms with multiple sclerosis (MS) but differs from it in a variety of ways. Previous studies have reported conflicting results trying to estimate the number of individuals affected by them which is why we designed this systematic review and meta-analysis to estimate the worldwide prevalence and incidence of NMOSD/NMO based on current evidence.

METHODS

We searched PubMed, Scopus, EMBASE, Web of Science, and gray literature including references from the identified studies, review studies, and conference abstracts which were published up to February 1, 2022. We used all MeSH terms pertaining to "NMOSD," "NMO," and all the terms on "prevalence," "incidence," and "epidemiology" to identify the search components. Pooled effect sizes were measured using random-effect model by DerSimonian-Laird.

RESULTS

The prevalence and incidence rates of NMOSD/NMO ranged from 0.07 to 10 and 0.029 to 0.880 per 100,000 population, respectively. The overall pooled prevalence of NMO per 100,000 population was 1.54 (I²: 98.4%, 95% CI: 1.13-1.96, P< 0.001) based on the 2006 criteria, 1.51 (I²: 99.4%, 95% CI: 1.21-1.81, P < 0.001) based on the 2015 criteria and 2.16 (I²: 89.4%, 95% CI: 1.46-2.86, P < 0.001) based on the 2006/2015 criteria. The overall annual incidence of NMO per 100,000 population was 0.155 (I²: 95%, 95% CI: 0.115-0.195, P < 0.001) based on the 2006 criteria and 0.278 (I²: 100%, 95% CI: 0.135-0.420, P < 0.001) based on the 2015 criteria. The prevalence rates were highest in French West Indies and South Korea, and lowest in Cuba and Australia, based on the 2006 and 2015 criteria, respectively. Also, the highest annual incidence rates were obtained for Sweden and Slovak republic and the lowest for Cuba and Australia based on the 2006 and 2015 criteria, respectively. All estimated rates were higher among females compared to males.

CONCLUSION

Although rare, NMOSD/NMO impact affected individuals in devastating ways. Several large-scale prospective studies are required to reach a comprehension of the epidemiological aspects of these notorious demyelinating conditions.

Factors associated with the misdiagnosis of neuromyelitis optica spectrum disorder

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune condition that is associated with severe disability. Approximately 40% of individuals are misdiagnosed with multiple sclerosis (MS) or other diseases. We aimed to define factors that influence the misdiagnosis of people with NMOSD and provide strategies for reducing error rates.

METHODS

A retrospective study was performed involving all people with a confirmed diagnosis of NMOSD within a single academic institution. Comprehensive clinical timelines were constructed for each individual that included presenting symptoms, provider type and timing of evaluations, aquaporin 4-IgG (AQP4) results, and MRI scans. Two-sample comparisons of continuous and categorial variables were performed for people accurately diagnosed with NMOSD and those originally misdiagnosed with another medical condition. A subanalysis of only AQP4-IgG positive people was also performed.

RESULTS

The study cohort included 199 people fulfilling International Panel criteria for NMOSD with 71 people (62 female; mean age at first symptom presentation (standard deviation (SD)) = 32.8 years (y) (SD 16.1)) being initially misdiagnosed and 128 people (106 female; 41.14y (SD 15.41)) who were accurately diagnosed. Of the 199 people with NMOSD, 166 had a positive serostatus. Identified factors associated with misdiagnosis, regardless of AQP4-IgG serostatus, were the presence of protracted nausea/vomiting/hiccups without any accompanying neurological symptoms, 23 (32.4%) versus 16 (12.5%) (p = 0.001), a longer median (range) time to see a neuroimmunology specialist 4.2y (0.14-31.8) versus 0.5y (0.0-21.2) (p<0.0001), and a delay in acquiring an MRI study, 4.7y (0.0-27.3) versus 0.3y (0.0-20.2) (p<0.0001). A greater proportion of people misdiagnosed were identified with a negative live-cell based AQP4-IgG serum test result, 13/13 (100%) versus 22/114 (19.3%) (p<0.0001). Additionally, the mean (SD) time between a first negative and successive live-cell based AQP4-IgG positive test result was greater for people misdiagnosed with another condition, 3.9y (SD 5.0) versus 1.5y (SD 2.1) (p = 0.01). Although not significant between groups, a rash was also reported in 63/199 people with NMOSD, with 31/63 having an anti-nuclear antibody titer ≥ 1:160.

CONCLUSION

Defined factors can help guide both generalists and specialists in the pursuit of strategies aimed at efficiently diagnosing those with NMOSD such that effective care can be delivered.

The description of neuromyelitis optica spectrum disorder: Patient registry in Yangtze River Delta area of China

OBJECTIVE

To describe the clinical features of neuromyelitis optica spectrum disorder (NMOSD) through patient registry in Yangtze River Delta area of China.

METHODS

A total of 502 consecutive patients diagnosed with aquaporin-4 antibody (AQP4-ab)-positive NMOSD were registered between December 2018 to January 2021 in multiple tertiary referral centers within the framework of Yangtze River Delta of China. Their baseline data were reviewed, and follow-up clinical information were collected prospectively.

RESULTS

The mean age at onset was 37.3 (range 3-80 years) years and the female-to-male ratio was 8.1:1. The median disease duration was 47 months (interquartile range [IQR] 25-84 months). A total of 1372 attacks of the 502 patients were recorded till the last follow-up, with a median annualized relapse rate of 0.4 (IQR 0.3-0.6). Nearly one-fourth (24.5%, 336/1372) of the attacks had prodromic events, including upper respiratory tract infection (36.3%, 122/336), fever (20.2%, 68/336) and pregnancy-related issues (17.9%, 60/336), etc. Myelitis was the most common attack type throughout the disease course (51.4%, 705/1372), followed by optic neuritis (ON, 43.1%, 592/1372). As for onset phenotype, ON (37.3%, 187/502) prevailed over myelitis (28.3%, 142/502). The median time to first relapse was 12 months (IQR 5-25 months). Patients with brainstem encephalitis at onset were more likely to have other anatomical region involved in subsequent attacks (p < 0.001), compared to other onset type. The median serum AQP4-ab titer measured by cell-based assays was 1:100 (IQR 1:32-1:320, range 1:10-1:10,000). The baseline AQP4-ab titer in cerebrospinal fluid (r = 0.542, p <0.001), overall ARR (r = 0.232, p< 0.001) and the EDSS scores at last follow-up (r = 0.119, p = 0.022) significantly correlated with baseline serum AQP4-ab titer. Antinuclear antibodies (48.4%), thyroid peroxidase antibodies (30.7%), and anti-SSA antibodies (26.2%) represented the most frequent concomitant antibodies, while autoimmune thyroid disorders (13.1%, 66/502) and Sjogren's syndrome (10.8%, 54/502) were the most common accompanying autoimmune diseases. Till the last follow-up, 403 patients received preventive treatments. Azathioprine represented the most common initial treatment, mycophenolate mofetil and rituximab was the most common second and third-line treatment, respectively. The EDSS score at the last follow-up ranged from 0 to 8.5 with a median of 2 (IQR 1-3).

CONCLUSIONS

A comprehensive clinical picture of patients with AQP4-ab-positive NMOSD in Yangtze River Delta area of China was presented. More information on disease tragedy and predictive prognostic factors could be generated through long-term observations.

Comparison on the effect of seven drugs to prevent relapses of neuromyelitis optica spectrum disorders: A modeling analysis of literature aggregate data

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) is an immune-mediated demyelinating disease of the central nervous system. This study aimed to perform a comprehensive comparison of the effect of seven drugs to prevent relapses of NMOSD.

METHOD

A literature search was conducted using public databases. Clinical studies on the seven drugs (eculizumab, inebilizumab, satralizumab, rituximab, tocilizumab, azathioprine, and mycophenolate mofetil) to prevent relapses of NMOSD were identified. A time-course model was established using the time to first relapse as the primary endpoint, in order to evaluate the long-term effect of each drug in preventing relapse.

RESULTS

Twenty-four trials, including 2207 patients, were included in the model analysis. The results showed that monoclonal antibody therapy could significantly prolong the time to first relapse. Among all seven drugs, eculizumab can most significantly prevent patient from relapse. The estimated proportion of relapse-free patients treated with eculizumab was 98.9% at 24 months.

CONCLUSION

Based on the construction of a time-course pharmacodynamic model, this study made a comprehensive quantitative comparison of seven drugs for the treatment of NMOSD for the first time. These results can not only serve as a quantitative supplement for the rational use of drugs in clinical practice but also provide a pharmacodynamic reference for clinical trial design and decision making in the future.

Incidence of neuromyelitis optica spectrum disorders in China: a large cohort study using claim data

OBJECTIVES

Population-based studies estimating the incidence of neuromyelitis optica spectrum disorders (NMOSDs) in Asia are limited, and the relationship between latitude and incidence has been scarcely investigated. We aimed to estimate the incidence of NMOSDs in Chinese adults and explore their relationship to latitude.

DESIGN

Cohort study based on data from the Urban Employee Basic Medical Insurance in China.

PARTICIPANTS

177 million people were followed from 2016 to 2017 in 20 provinces.

PRIMARY OUTCOME MEASURES

The incidence rate was estimated by Poisson distribution and reported as age-adjusted and sex-adjusted rates using the standard population.

RESULTS

There were 1313 incident NMOSD cases, with an overall incidence of 0.41 (95% CIs: 0.39 to 0.43) per 100 000 person-years. The incidence in females was higher, with a female-to-male IRR of 4.52. The incidence increased with age, peaking at 55-64 years in females and 65-74 years in males and then decreasing thereafter. The female-to-male IRRs were higher in those <55 years. The association between latitude and incidence was not statistically significant.

CONCLUSIONS

The incidence of NMOSD in Chinese adults was 0.41 per 100 000 person-years. There is no latitude gradient observed. Sex and age influence the risk of NMOSD, suggesting the role of genetic, hormonal and other related factors in the pathophysiology.

Evaluating the Economic Burden of Relapses in Neuromyelitis Optica Spectrum Disorder: A Real-World Analysis Using German Claims Data

Introduction

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disease of the central nervous system which causes recurrent relapses, resulting in blindness, paralysis, and spinal cord damage. This study sought to explore the real-world burden, treatment, and cost of NMOSD in Germany using claims data.

Methods

Our study consisted of a retrospective analysis of two anonymized health insurance datasets covering around 9 million patients in Germany from 01/01/2013 to 31/12/2019. NMOSD patients were identified using inpatient and outpatient International Classification of Diseases, Tenth Revision (ICD-10) diagnoses of neuromyelitis optica (NMO; G36.0) and relevant symptom codes. Active periods of disease were identified based on relapse events (including hospitalizations and acute treatment); healthcare resource utilization (HCRU) and direct costs were allocated to active and inactive periods based on treatment dates. Propensity score matching was used to compare HCRU and cost outcomes among patients with and without NMOSD.

Results

Overall, 130 patients were identified as having NMOSD (mean age: 46.84 years; 58% female). NMOSD patients recorded 16.52 active and 348.48 inactive days per patient year (PPY). HCRU and associated costs were approximately tenfold higher during active periods than during inactive periods, with the largest share of the cost difference driven by hospitalizations (€6424.09/€259.10 per active/inactive month) and outpatient drug prescriptions (€412.83/€271.58). Direct healthcare costs incurred by patients with NMOSD (€12,913.28 PPY) were approximately threefold higher than those incurred by patients without NMOSD (€4667.66 PPY). Costs of hospitalization (€6448.32/€1937.64 PPY) and outpatient prescriptions (€3335.67/€1037.64 PPY) contributed most strongly to the difference.

Conclusion

Patients with NMOSD consume substantial healthcare resources and incur heavy costs during active disease phases. This study captured direct measurable healthcare costs and likely underestimates the real societal/emotional burden on patients and their families. Nevertheless, prevention of acute relapses represents one compelling strategy to minimize the economic burden of NMOSD in Germany.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-021-00311-x.

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.

Safety and efficacy of interleukin-6-receptor inhibitors in the treatment of neuromyelitis optica spectrum disorders: a meta-analysis

BACKGROUND

Interleukin-6-receptor inhibitors like Tocilizumab and Satralizumab are showing promising results in the treatment of Neuromyelitis Optica spectrum disorder (NMOSD). We aimed to investigate the efficacy and safety of various Interleukin-6-receptor inhibitors in the management of NMO/NMOSD.

METHODS

PubMed, Embase, and The Cochrane Library were systematically searched for suitable studies. Change in Annualized Relapse Ratio (ARR), Change in Extended Disability Status Scale (EDSS) s, the proportion of relapse-free patients and proportion of patients with adverse events, including serious adverse events and mortality were the parameters considered for the meta-analysis for Tocilizumab. Mean difference (MD) with 95% CI was used to quantify the change in ARR and change in EDSS before and after treatment. A forest plot was prepared to indicate the efficacy and adverse effects outcomes. The results were compared with those of Satralizumab included in two trials.

RESULTS

A total of nine studies with 202 patients were included in our study. Tocilizumab found a good proportion (76.95% CI: 0.61-0.91; p < 0.001) of relapse free patients at follow up. It also significantly reduced mean ARR (mean difference: -2.6, 95% CI: - 2.71 to - 1.68; p < 0.001) and but did not show significant difference in change in EDSS score (mean difference = - 0.79, 95% CI: - 1.89 to - 0.31; p = 0.16). Also, the toxicity profile of Tocilizumab was acceptable considering the proportions of patients with adverse events 56% (95% C.I.;0.27-0.85, I2 = 88.95%, p < 0.001), proportions of patients with serious adverse events 11% (95% C.I.; 0.05 to 0.17, I2 = 0%, p < 0.001) and zero treatment related deaths. SAkura studies for Satralizumab showed similar relapse free patients (70% to 80%) and reduction of ARR and EDSS from baseline. Some studies of Tocilizumab have shown to reduce pain and fatigue while trials of Satralizumab had non-significant findings.

CONCLUSION

Interleukin-6-receptor inhibitors therapy showed a promising result with good efficacy and acceptable adverse events profile for treatment of NMOSD.

Neuromyelitis optica spectrum disorders: A nationwide Portuguese clinical epidemiological study

INTRODUCTION

Neuromyelitis optica spectrum disorder (NMOSD) is a rare disorder in which astrocyte damage and/or demyelination often cause severe neurological deficits.

OBJECTIVE

To identify Portuguese patients with NMOSD and assess their epidemiological/clinical characteristics.

METHODS

This was a nationwide multicenter study. Twenty-four Portuguese adult and 3 neuropediatric centers following NMOSD patients were included.

RESULTS

A total of 180 patients met the 2015 Wingerchuk NMOSD criteria, 77 were AQP4-antibody positive (Abs+), 67 MOG-Abs+, and 36 seronegative. Point prevalence on December 31, 2018 was 1.71/100,000 for NMOSD, 0.71/100,000 for AQP4-Abs+, 0.65/100,000 for MOG-Abs+, and 0.35/100,000 for seronegative NMOSD. A total of 44 new NMOSD cases were identified during the two-year study period (11 AQP4-Abs+, 27 MOG-Abs+, and 6 seronegative). The annual incidence rate in that period was 0.21/100,000 person-years for NMOSD, 0.05/100,000 for AQP4-Abs+, 0.13/100,000 for MOG-Abs+, and 0.03/100,000 for seronegative NMOSD. AQP4-Abs+ predominated in females and was associated with autoimmune disorders. Frequently presented with myelitis. Area postrema syndrome was exclusive of this subtype, and associated with higher morbidity/mortality than other forms of NMOSD. MOG-Ab+ more often presented with optic neuritis, required less immunosuppression, and had better outcome.

CONCLUSION

Epidemiological/clinical NMOSD profiles in the Portuguese population are similar to other European countries.

[Clinical and epidemiological aspects of neuromyelitis optic spectrum diseases in the russian population]

OBJECTIVE

To present clinical and epidemiological aspects of neuromyelitis optica spectrum disorders (NMOSD) in the Russian Federation.

MATERIAL AND METHODS

We studied 142 patients who met diagnostic criteria of 2015 for NMOSD. Sex, age at disease onset, presence or absence of aquaporin-4 immunoglobulin G antibodies (AQP4-IgG), mail clinical symptoms, oligoclonal IgG, therapy for the treatment of exacerbations and prevention of exacerbations, compliance with 2006 diagnostic criteria were assessed.

RESULTS

The prevalence of women is 4.26:1, the most frequent age at disease onset is 18-29 years (36% of cases). The laboratory aspects of the disease are characterized and approaches to the treatment and prevention of exacerbations of NMOSD in patients of the Russian population are evaluated. Approaches to diagnostics are compared depending on the applied diagnostic criteria (34% of patients do not meet neuromyelitis optica 2006 diagnostic criteria). A prognosis for the prevalence of NMOSD in the Russian population has been proposed: 0.45-4.21/100000.

CONCLUSION

This is the first published data on clinical and epidemiological characteristics of NMOSD in the Russian Federation.

[Epidemiology of neuromyelitis optica spectrum disorder]

Neuromyelitis optica spectrum disorder (NMOSD) is a group of rare and mostly severe autoimmune demyelinating central nervous system disorders which prevalence is 0.7-1 per 100.000 population and incidence is 0.037-0.73 per 100.000 person-years. NMOSD may present as a combination of uni- or bilateral optic neuritis, transverse myelitis or lesions of brain stem and other brain regions. The symptoms are mostly relapsing (up to 97.5%) and progressive. Occurrence of relapses is associated with seropositivity for aquaporin-4 (up to 80% of NMOSD patients) and bears a less favorable prognosis (mortality up to 32%). Women seropositive for aquaporin 4 constitute 90% of NMOSD patients. Compared to other demyelinating disorders, NMOSD is characterized by late onset (mean age is about 39 years) and association with other autoimmune disorders, including systemic lupus erythematosus, myasthenia gravis and Sjogren's syndrome. A genetic predisposition was found among Blacks and Asians, with HLA-DRB1*03:01 gene associated with higher risk of NMOSD in Asians. The course of the disease tends to be more severe in Blacks. There are clusters of an increased incidence of NMOSD in the Carribeans and in the Far East. Continued increase of prevalence and incidence of NMOSD worldwide compels continued epidemiological research in order to provide early diagnosis and treatment for this disorder.

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.

Patient-reported safety and tolerability of the COVID-19 vaccines in persons with rare neuroimmunological diseases

Background

The COVID-19 vaccines are currently recommended for people with rare neuroimmunological diseases such as neuromyelitis optica spectrum disorder (NMOSD), MOG-antibody disease (MOGAD), and transverse myelitis. However, the safety profile of the vaccines in this population is uncertain.

Objective

To report real-world safety data of the COVID-19 vaccines in persons with rare neuroimmunological diseases.

Methods

An anonymous survey was distributed to patients recruited on social media. Participants answered general demographic and disease-related questions, and specific questions about their experiences with the COVID-19 vaccines.

Results

438 participants completed the questionnaire. The median age was 51 (range 18–82 years); 366 were female (83.6%); 102 (23.3%) had associated comorbidities, and 354 (80.1%) were treated with immunotherapies. 242 participants (55.3%) reported a diagnosis of NMOSD; 99 (22.6%) had MOGAD; 79 (18%) had transverse myelitis. 239 participants (66.2%) were younger than 55 years of age. 138 participants (31.5%) reported earlyadverse events. Of these, 93 (67.4%) were < 55 years old, and 45 (32.6%) were > 55 years old (p=0.0086). The most common adverse events were local reactions, including pain, redness, and swelling at the injection site, reported by 155 participants (35.4%). 73 participants (16.7%) reported new or worsening neurological symptoms following the vaccination. Most symptoms occurred within the first week after vaccination and resolved within three days.

Conclusions

This survey indicates an overall favorable safety and tolerability profile of the COVID-19 vaccines among persons with rare neuroimmunological diseases. Longer-term studies are warranted to confirm these data.

Incidence and prevalence of neuromyelitis optica spectrum disorders in Slovakia

OBJECTIVE

: Neuromyelitis optica spectrum disorders (NMOSDs) are a group of rare, inflammatory, demyelinating diseases that affect the central nervous system. Neither the incidence nor the prevalence of NMOSD has been determined in Slovakia thus far. The aim of this study was to determine both the incidence and the prevalence of NMOSD in Slovakia using the 2015 International Panel of NMOSD diagnosis (IPND) criteria.

METHODS

: We performed a population-based study in Slovakia to estimate both the incidence and the prevalence of NMOSD during the period from 1 January 2006 through 31 December 2019. NMOSD cases were reported from multiple sources and the diagnosis was subsequently verified using the IPND criteria by a joint commitee of three neurologists. The prevalence is reported as number of cases per 100,000 inhabitans and the incidence as number of new cases per 1,000,000 person-years. Age-adjusted rates to the WHO standard population 2005-2025 were also calculated.

RESULTS

: We identified 63 NMOSD cases. The crude point-prevalence rate was 1.37 (95% CI 1.03-1.71) per 100,000 inhabitants. The crude indidence rate was 0.88 (95% CI 0.65-1.12) per 1,000,000 person-years. The age-adjusted point-prevalence rate was 1.42 (95% CI 1.07-1.84) per 100,000 persons and the age-adjusted incidence rate was 0.96 (95% CI 0.72-1.25) per 1,000,000 person-years.

CONCLUSION

: The NMOSD epidemiological situation in Slovakia is comparable to those reported from other Caucasian populations.

Status of the neuromyelitis optica spectrum disorder in Latin America

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) is an increasing diagnostic and therapeutic challenge in Latin America (LATAM). Despite the heterogeneity of this population, ethnic and socioeconomic commonalities exist, and epidemiologic studies from the region have had a limited geographic and population outreach. Identification of some aspects from the entire region are lacking.

OBJECTIVES

To determine ethnic, clinical characteristics, and utilization of diagnostic tools and types of therapy for patients with NMOSD in the entire Latin American region.

METHODS

The Latin American Committee for Treatment and Research in MS (LACTRIMS) created an exploratory investigational survey addressed by Invitation to NMOSD Latin American experts identified through diverse sources. Data input closed after 30 days from the initial invitation. The questionnaire allowed use of absolute numbers or percentages. Multiple option responses covering 25 themes included definition of type of practice; number of NMOSD cases; ethnicity; utilization of the 2015 International Panel criteria for the diagnosis of Neuromyelitis optica (IPDN); clinical phenotypes; methodology utilized for determination of anti-Aquaporin-4 (anti- AQP4) antibodies serological testing, and if this was performed locally or processed abroad; treatment of relapses, and long-term management were surveyed.

RESULTS

We identified 62 investigators from 21 countries reporting information from 2154 patients (utilizing the IPDN criteria in 93.9% of cases), which were categorized in two geographical regions: North-Central, including the Caribbean (NCC), and South America (SA). Ethnic identification disclosed Mestizos 61.4% as the main group. The most common presenting symptoms were concomitant presence of optic neuritis and transverse myelitis in 31.8% (p=0.95); only optic neuritis in 31.4% (more common in SA), p<0.001); involvement of the area postrema occurred in 21.5% and brain stem in 8.3%, both were more frequent in the South American cases (p<0.001). Anti-AQP4 antibodies were positive in 63.9% and anti-Myelin Oligodendrocyte Glycoprotein (MOG) antibodies in 4.8% of total cases. The specific laboratorial method employed was not known by 23.8% of the investigators. Acute relapses were identified in 81.6% of cases, and were treated in 93.9% of them with intravenous steroids (IVS); 62.1% with plasma exchange (PE), and 40.9% with intravenous immunoglobulin-G (IVIG). Therapy was escalated in some cases due to suboptimal initial response. Respondents favored Rituximab as long-term therapy (86.3%), whereas azathioprine was also utilized on 81.8% of the cases, either agent used indistinctly by the investigators according to treatment accessibility or clinical judgement. There were no differences among the geographic regions.

CONCLUSIONS

This is the first study including all countries of LATAM and the largest cohort reported from a multinational specific world area. Ethnic distributions and phenotypic features of the disease in the region, challenges in access to diagnostic tools and therapy were identified. The Latin American neurological community should play a determinant role encouraging and advising local institutions and health officials in the availability of more sensitive and modern diagnostic methodology, in facilitating the the access to licensed medications for NMOSD, and addressing concerns on education, diagnosis and management of the disease in the community.

Mortality of neuromyelitis optica spectrum disorders in a Chinese population

Objective

Neuromyelitis optica spectrum disorder (NMOSD) is a rapidly disabling disease. Epidemiologic studies have suggested varying NMOSD mortality across ethnic groups. However, NMOSD mortality data in China are scarce. This study’s objectives were to explore mortality and causes of death among Chinese NMOSD patients and to identify independent predictors of death.

Methods

We performed a retrospective study with a 10‐year follow‐up of Chinese NMOSD patients. A Cox proportional hazards model was used to identify independent predictors of death.

Results

Five hundred and sixty‐nine patients were included; 24 patients died during follow‐up, for overall mortality of 4.2%. In these patients, the median disease duration at the time of death was 3.4 years. The most common cause of death was secondary infection (62.5%), especially respiratory infection (45.8%). The second most common cause of death was extensive cervical myelitis with respiratory failure (16.7%). Other causes included suicide (8.3%), cancer (4.2%), cerebral embolism (4.2%), and unknown causes (4.2%). The multivariate Cox analyses indicated that a short first interattack interval (HR = 0.93, 95% CI 0.89–0.98, p = 0.003), lack of regular immunotherapy (HR = 10.34, 95% CI 4.05–26.37, p < 0.001), and older age at onset were independent predictors of death. Every increasing decade of onset age increased the risk of death 2.59 times (95% CI 1.74–3.86, p < 0.001).

Interpretation

Infections were more common in patients not treated with any immunotherapy, indicating that early and consequent immunotherapy might prevent death by infections, which is of great importance for further treatment of NMOSD patients to avoid undertreatment due to fear of treatment‐associated infections.

Drug Treatment of Neuromyelitis Optica Spectrum Disorders: Out with the Old, in with the New?

Introduction

Neuromyelitis optica spectrum disorders (NMOSD) are rare neuroinflammatory demyelinating diseases of the CNS, mainly affecting optic nerves, spinal cord and brainstem regions. The diagnosis depends on clinical symptoms, MRI findings and the detection of autoantibodies against the water channel aquaporin 4 (AQP4-Ab). This autoantibody is particularly important for diagnostic sensitivity and specificity and further sets the course for major therapeutic decisions. Due to a relapsing course with the accumulation of disability, relapse prevention by immunotherapy is crucial in NMOSD. Until recently, disease-modifying agents specific to NMOSD were not available, and patients were treated with various immunosuppressive drugs and regimens - with variable success. Fortunately, since 2019, three new therapeutic antibodies have entered the market.

Areas Covered

We aim to shortly summarise the pathogenesis and biological targets for acute and preventive therapy of adult NMOSD. We will focus on conventional immunotherapies and the recently approved novel biological drugs satralizumab, eculizumab and inebilizumab, and conclude with a brief outlook on future therapeutic approaches.

Expert Opinion

Although satralizumab, eculizumab and inebilizumab are a breakthrough concerning short-term efficacy, important questions on their future use remain open. There is no data from head-to-head comparisons, and data on long-term safety and efficacy of the new medicines are pending. Whether any of the biologics are efficacious in AQP4-Ab negative NMOSD patients is not yet known – as is how they will succeed in non-responders to conventional immunotherapies. Further, (autoimmune) comorbidities, affordability, and market availability of drugs may be decisive factors for choosing treatments in the near future. We are fortunate to have these new drugs available now, but they will not immediately supersede established off-label drugs in this indication. It is still too early to definitively revise the treatment algorithms for NMOSD - although we are probably on the way.

[From neuromyelitis optica to neuromyelitis optica spectrum disorder: from clinical syndrome to diagnistic classification]

Neuromyelitis optica spectrum disorder (NMOSD), derived from NMO or Devic's disease, is considered as a distinct disease since the discovery of a novel and pathogenic serum autoantibody targeting aquaporin‑4 (AQP4-IgG) and is distinguished from classical multiple sclerosis (MS). With the continuous extension of knowledge on the clinical manifestations, the previously narrow diagnostic term NMO became NMOSD, which has also been used in the diagnostic criteria since 2015. The current diagnostic criteria enable the early diagnosis of NMOSD in patients with and without AQP4-IgG. Typical clinical manifestations include involvement of the spinal cord, optic nerve and brainstem. Typically patients with the disease also present with neuropathic pain, painful tonic spasms and also other unusual manifestations in NMOSD. Especially in AQP4-IgG positive NMOSD patients, the coexistence with other autoimmune diseases is frequently observed. In most cases NMOSD follows a relapsing course with exacerbation-free periods sometimes lasting years and can be manifested first in advanced adulthood. A subset of AQP4-IgG negative NMOSD patients have been found to harbor autoantibodies targeting myelin oligodendrocyte glycoprotein (MOG), which is considered as a distinct disease entity: these MOG antibody-associated disorders (MOGAD) can present with clinical syndromes resembling both NMOSD and MS and are currently the subject of intensive research.

Population-based head-to-head comparison of the clinical characteristics and epidemiology of AQP4 antibody-positive NMOSD between two European countries

BACKGROUND

Population-based clinical studies in neuromyelitis optica spectrum disorder (NMOSD) and epidemiological and clinical comparisons of White ethnicities are missing. In a large population-based international cohort, we extensively characterized aquaporin-4 antibody seropositive (AQP4-Ab+) NMOSD, and also compared the clinical, radiological and epidemiological features between two European populations residing in different areas.

METHODS

Between self-reported Danish and Hungarian ethnicities, we compared the population-based clinical features, disability outcomes, and death of 134 AQP4-Ab+ NMOSD cases fulfilling the 2015 International Panel for NMO Diagnosis (IPND) criteria. For precise comparison of epidemiology, we conducted a population-based head-to-head comparative study of the age-standardized prevalence (January 1, 2014) and incidence (2007-2013) of AQP4-Ab+ NMO/NMOSD among adults (≥16 years) in Denmark (4.6 million) and Hungary (6.4 million) by applying 2015 IPND (NMOSD) criteria and 2006 Wingerchuk (NMO).

RESULTS

Danes were more likely to present with transverse myelitis and were more affected by spinal cord damage on long-term disability. Hungarians presented most often with optic neuritis, although visual outcome was similar in the groups. No differences were observed in sex, disease course, relapse rate, autoimmune comorbidity, mortality, brain MRI, and treatment strategies. The age-standardized prevalence estimates of AQP4-Ab+ NMOSD (2015 IPND criteria) in Denmark vs. Hungary were 0.66 vs. 1.43 (/100,000) while incidence rates were 0.04 vs. 0.11 (/100,000 person-years); similar differences were found based on the 2006 NMO criteria.

CONCLUSIONS

This head-to-head comparative study indicates different disease characteristics and epidemiology among White populations in Europe, and substantiates the need for population-based genetic and environmental studies in NMOSD.

Prevalence of neuromyelitis optica spectrum disorder in Belo Horizonte, Southeast Brazil

BACKGROUND

Studies on the prevalence of neuromyelitis optica spectrum disorder (NMOSD) are still scarce. The aim of the current study was to determine the prevalence rate of NMOSD in Belo Horizonte, southeast Brazil, where the prevalence rate of multiple sclerosis (MS) has already been established.

METHODS

For this observational study, eligible patients had to meet the 2015 International Panel for Neuromyelitis Optica Diagnosis, be seen at the study center between January 2000 and February 2019 and live in Belo Horizonte. The prevalence rate of NMOSD was estimated based on the number of MS and NMOSD patients seen at same Center during the same period, and the previously established prevalence of MS in Belo Horizonte.

RESULTS

During the study period, there were 69 patients with NMOSD, 60 (87.0%) of whom were females, and 44 (63.8%) non-whites. The median age at disease onset was 36.7 (4-72) years, the mean EDSS score 4.78±2.36, and the mean ARR 0.57±0.43. Anti-aquaporin-4 immunoglobulin testing was available for 61 (88.4%) patients, of whom 41 (67.2%) had a positive result. During the same period, 280 MS patients were seen. Considering the local known prevalence rate of MS of 18.1/100,000 inhabitants, the estimated NMOSD prevalence rate in Belo Horizonte was 4.52/100,000 (95% CI 3.72-5.43) inhabitants.

CONCLUSION

The prevalence rate of NMOSD in Belo Horizonte is high as compared with those found in most of the studies reported to date.

Worldwide Incidence and Prevalence of Neuromyelitis Optica: A Systematic Review

Objective

Since the last epidemiologic review of neuromyelitis optica/neuromyelitis optica spectrum disorder (NMO/NMOSD), 22 additional studies have been conducted. We systematically review the worldwide prevalence, incidence, and basic demographic characteristics of NMOSD and provide a critical overview of studies.

Methods

PubMed, Ovid MEDLINE, and Embase using Medical Subject Headings and keyword search terms and reference lists of retrieved articles were searched from 1999 until August 2019. We collected data on the country; region; methods of case assessment and aquaporin-4 antibody (AQP4-Ab) test; study period; limitations; incidence (per 100,000 person-years); prevalence (per 100,000 persons); and age-, sex-, and ethnic group–specific incidence or prevalence.

Results

We identified 33 relevant articles. The results indicated the highest estimates of incidence and prevalence of NMOSD in Afro-Caribbean region (0.73/100 000 person-years [95% CI: 0.45–1.01] and 10/100 000 persons [95% CI: 6.8–13.2]). The lowest incidence and prevalence of NMOSD were found in Australia and New Zealand (0.037/100 000 person-years [95% CI: 0.036–0.038] and 0.7/100,000 persons [95% CI: 0.66–0.74]). There was prominent female predominance in adults and the AQP4-Ab–seropositive subpopulation. The incidence and prevalence peaked in middle-aged adults. African ethnicity had the highest incidence and prevalence of NMOSD, whereas White ethnicity had the lowest. No remarkable trend of incidence was described over time.

Conclusion

NMOSD is a rare disease worldwide. Variations in prevalence and incidence have been described among different geographic areas and ethnicities. These are only partially explained by different study methods and NMO/NMOSD definitions, highlighting the need for specifically designed epidemiologic studies to identify genetic effects and etiologic factors.

Epidemiological findings of neuromyelitis optica spectrum disorders in a Venezuelan study

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD), is a rare autoimmune inflammatory disease of the central nervous system. Since the countries of Latin America (LATAM) show contrast in geographic, social, environmental factors, and genetic heterogeneity, the information about NMOSD epidemiology in the region allows a better understanding of the disease and its clinical outcome.

OBJECTIVES

To determine the prevalence, relative frequency (RF), and clinical characteristics of NMOSD in a multiethnic Venezuelan cohort of patients with demyelinating disorders.

METHODS

We conducted a retrospective descriptive multicenter study of hospital case records of individuals with an established diagnosis of MS and NMOSD in the National Program for Multiple sclerosis (MS) from 2011 to 2018. We selected those NMOSD cases based on the 2006 Wingerchuck and the 2015 International panel for the diagnosis of Neuromyelitis optica (IPND) criteria.

RESULTS

We identified 249 patients with NMOSD. The prevalence was 2.11 per100,000 individuals (95% confidence interval (CI)1.85 2.37), the RF was 23%, and the MS/NMOSD ratio was 3.2:1. The average disease onset occurred by the fourth decade of life (34±14.8 years of age); with a strong female predominance (female to male ratio: 4:1). Mestizos constituted 86,7% of this cohort. Most of the patients presented initially with simultaneous optic neuritis (ON) and acute transverse myelitis (ATM) and a recurrent course was registered in 82.3% of cases. The mean of the expanded disability status scale (EDSS) was 3.5 (IQR 2-7). Abnormal brain and spine MRI were present in 47.8% and 81.1% of patients, respectively. Antibodies against aquaporin-4 (AQP4) which were measured through a cell-based assay were positive in 55.3% of the individuals tested. The most used immunosuppressant agent was Azathioprine (57.4%).

CONCLUSION

NMOSD in Venezuela affects mainly young Mestizo women and shows one of the highest relative frequency in the region. Planning and developing healthcare programs for underserved populations as well as more comprehensive LATAM studies are required to identify the distribution and variations of its epidemiological picture.

Neuromyelitis optica

Neuromyelitis optica (NMO; also known as Devic syndrome) is a clinical syndrome characterized by attacks of acute optic neuritis and transverse myelitis. In most patients, NMO is caused by pathogenetic serum IgG autoantibodies to aquaporin 4 (AQP4), the most abundant water-channel protein in the central nervous system. In a subset of patients negative for AQP4-IgG, pathogenetic serum IgG antibodies to myelin oligodendrocyte glycoprotein, an antigen in the outer myelin sheath of central nervous system neurons, are present. Other causes of NMO (such as paraneoplastic disorders and neurosarcoidosis) are rare. NMO was previously associated with a poor prognosis; however, treatment with steroids and plasma exchange for acute attacks and with immunosuppressants (in particular, B cell-depleting agents) for attack prevention has greatly improved the long-term outcomes. Recently, a number of randomized controlled trials have been completed and the first drugs, all therapeutic monoclonal antibodies, have been approved for the treatment of AQP4-IgG-positive NMO and its formes frustes.

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.

Therapeutic Plasma Exchange as a Treatment for Autoimmune Neurological Disease

Introduction

Therapeutic plasma exchange (TPE) is commonly used as treatment of certain autoimmune neurological diseases (ANDs), and its main objective is the removal of pathogenic autoantibodies. Our aim was to describe the clinical profile and the experience with the usage of TPE in patients with ANDs at our institution.

Methods

This is an observational retrospective study, including medical records of patients with diagnosis of ANDs who received TPE, between 2011 and 2018. Characteristics of TPE, such as number of cycles, type of replacement solution, and adverse effects, were evaluated. The modified Rankin Scale (mRS) was applied to measure the clinical response after the therapy.

Results

187 patients were included with the following diagnoses: myasthenia gravis (MG), n = 70 (37%); Guillain–Barré syndrome (GBS), n = 53 (28.3%), neuromyelitis optica spectrum disorders (NMOSD), n = 35 (18.7%); chronic inflammatory demyelinating polyneuropathy (CIDP), n = 23 (12.2%); and autoimmune encephalitis (AE), n = 6 (3.2%). The most used types of replacement solution were albumin (n = 131, 70%) and succinylated gelatin (n = 45, 24%). All patients received a median of five cycles (IQR 5-5). Hypotension and hydroelectrolytic disorders were the main complications. After TPE, 99 patients (52.9%) showed improvement in the mRS scores and a statistical significance (p < 0.05) was seen between the admission score and after TPE for every diagnosis except for CIDP.

Conclusion

TPE has an adequate safety profile, and improvement in functionality in treated patients reflects its effectiveness.

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.

Relapse Patterns in NMOSD: Evidence for Earlier Occurrence of Optic Neuritis and Possible Seasonal Variation

Neuromyelitis optica spectrum disorders (NMOSD) and multiple sclerosis (MS) show overlap in their clinical features. We performed an analysis of relapses with the aim of determining differences between the two conditions. Cases of NMOSD and age- and sex-matched MS controls were collected from across Australia and New Zealand. Demographic and clinical information, including relapse histories, were recorded using a standard questionnaire. There were 75 cases of NMOSD and 101 MS controls. There were 328 relapses in the NMOSD cases and 375 in MS controls. Spinal cord and optic neuritis attacks were the most common relapses in both NMOSD and MS. Optic neuritis (p < 0.001) and area postrema relapses (P = 0.002) were more common in NMOSD and other brainstem attacks were more common in MS (p < 0.001). Prior to age 30 years, attacks of optic neuritis were more common in NMOSD than transverse myelitis. After 30 this pattern was reversed. Relapses in NMOSD were more likely to be treated with acute immunotherapies and were less likely to recover completely. Analysis by month of relapse in NMOSD showed a trend toward reduced risk of relapse in February to April compared to a peak in November to January (P = 0.065). Optic neuritis and transverse myelitis are the most common types of relapse in NMOSD and MS. Optic neuritis tends to occur more frequently in NMOSD prior to the age of 30, with transverse myelitis being more common thereafter. Relapses in NMOSD were more severe. A seasonal bias for relapses in spring-summer may exist in NMOSD.

[Neuromyelitis optica and neuromyelitis optica spectrum disorders]

The review is devoted to up-to-date data on epidemiology, aspects of the pathogenesis of neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorders (NMOSD). The authors consider a role of myelin oligodendrocyte glycoprotein immunoglobulin G (MOG-IgG) in the syndromes phenotypically similar to NMO and NMOSD. Special attention is drawn to the methods of MOG-IgG antibodies detection and indications for testing. The approaches and management for treatment and prevention of NMO relapses, risks of complications during pregnancy and immediately after delivery, as well as methods for their prevention and treatment, are described.