The prevalence of long spinal cord lesions and anti-aquaporin 4 antibodies in neuromyelitis optica patients in Taiwan

Impact of comorbidities on relapsing rates of Neuromyelitis Optica Spectrum Disorders: Insights from a longitudinal study in Taiwan

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory demyelinating disease characterized by relapsing clinical episodes and the presence of autoantibodies. The impact of comorbidities on relapsing rate of NMOSD patients in Taiwan remains unclear.

METHODS

We conducted a longitudinal retrospective study using the largest hospital system in Taiwan from 2006 to 2021. Demographic characteristics, annualized relapse rates (ARR), and comorbidities were examined.

RESULTS

We identified 485 NMOSD patients from 2006 to 2021. Of these, 466 had the adult form and 19 (3.9 %) had the pediatric form of NMOSD. The median ARR was 0.51 (interquartile range (IQR): 0.26-1.11) for adults and 0.39 (IQR: 0.21-0.77) for pediatric patients. Comorbidities included malignancy (6.7 %) and autoimmune diseases (21.7 %). The recommended age for malignancy surveillance in NMOSD patients was 43.3 years. Neither malignancy nor autoimmune disease increased the ARR within 3 years post diagnosis in NMOSD patients with comorbidities compared with those without comorbidities.

CONCLUSIONS

Our study revealed the ARR within the initial three years after diagnosis was significantly higher, emphasizing the importance of early treatment. We also observed an association between malignancy and NMOSD, and a significantly higher risk of malignancy in adult patients with NMOSD than in the general population (the relative risk was 5.99) that requiring further investigations into the underlying mechanisms. These findings contribute to a better understanding of NMOSD and its comorbidities in Taiwan.

Clinical analysis of neuromyelitis optica spectrum disease with area postrema syndrome as the initial symptom

OBJECTIVE

The objective of this study was to report and discuss clinical analysis, including the diagnosis and treatment of 4 cases of neuromyelitis optica spectrum disease (NMOSD) with area postrema syndrome (APS) as the first symptom.

METHODS

Four patients with intractable nausea, vomiting, and confirmed NMOSD were included in the final analysis. All of these patients were initially misdiagnosed and mismanaged.

RESULTS

Among the 4 patients, 3 were admitted to the department of gastroenterology at the onset of the disease, and 2 were not correctly diagnosed and treated promptly due to misdiagnosis. Therefore, their symptoms worsened, and they were transferred to Intensive Care Unit (ICU) for life support. No obvious early medulla lesions were found in one patient. One patient was treated with intravenous immunoglobulin, methylprednisolone, and plasma exchange, but there was no significant clinical improvement, after which the disease relapsed during the treatment with low-dose rituximab.

CONCLUSION

The clinical manifestations of NMOSD are complex and diverse, and the initial symptoms, onset age of the patient, and magnetic resonance imaging (MRI) findings can influence the final diagnosis. Early identification of the APS and timely therapy can prevent visual and physical disabilities, even respiratory failure, coma, and cardiac arrest. Therefore, it is necessary to identify specific and sensitive serum and imaging markers for predicting the prognosis and recurrence of the disease.

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

BACKGROUND/PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

MRI Patterns Distinguish AQP4 Antibody Positive Neuromyelitis Optica Spectrum Disorder From Multiple Sclerosis

Neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) are inflammatory diseases of the CNS. Overlap in the clinical and MRI features of NMOSD and MS means that distinguishing these conditions can be difficult. With the aim of evaluating the diagnostic utility of MRI features in distinguishing NMOSD from MS, we have conducted a cross-sectional analysis of imaging data and developed predictive models to distinguish the two conditions. NMOSD and MS MRI lesions were identified and defined through a literature search. Aquaporin-4 (AQP4) antibody positive NMOSD cases and age- and sex-matched MS cases were collected. MRI of orbits, brain and spine were reported by at least two blinded reviewers. MRI brain or spine was available for 166/168 (99%) of cases. Longitudinally extensive (OR = 203), "bright spotty" (OR = 93.8), whole (axial; OR = 57.8) or gadolinium (Gd) enhancing (OR = 28.6) spinal cord lesions, bilateral (OR = 31.3) or Gd-enhancing (OR = 15.4) optic nerve lesions, and nucleus tractus solitarius (OR = 19.2), periaqueductal (OR = 16.8) or hypothalamic (OR = 7.2) brain lesions were associated with NMOSD. Ovoid (OR = 0.029), Dawson's fingers (OR = 0.031), pyramidal corpus callosum (OR = 0.058), periventricular (OR = 0.136), temporal lobe (OR = 0.137) and T1 black holes (OR = 0.154) brain lesions were associated with MS. A score-based algorithm and a decision tree determined by machine learning accurately predicted more than 85% of both diagnoses using first available imaging alone. We have confirmed NMOSD and MS specific MRI features and combined these in predictive models that can accurately identify more than 85% of cases as either AQP4 seropositive NMOSD or MS.

Magnetic resonance imaging in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease of the central nervous system (CNS) associated with antibodies to aquaporin-4 (AQP4), which has distinct clinical, radiological and pathological features, but also has some overlap with multiple sclerosis and myelin oligodendrocyte glycoprotein (MOG) antibody associated disease. Early recognition of NMOSD is important because of differing responses to both acute and preventive therapy. Magnetic resonance (MR) imaging has proved essential in this process. Key MR imaging clues to the diagnosis of NMOSD are longitudinally extensive lesions of the optic nerve (more than half the length) and spinal cord (three or more vertebral segments), bilateral optic nerve lesions and lesions of the optic chiasm, area postrema, floor of the IV ventricle, periaqueductal grey matter, hypothalamus and walls of the III ventricle. Other NMOSD-specific lesions are denoted by their unique morphology: heterogeneous lesions of the corpus callosum, 'cloud-like' gadolinium (Gd)-enhancing white matter lesions and 'bright spotty' lesions of the spinal cord. Other lesions described in NMOSD, including linear periventricular peri-ependymal lesions and patch subcortical white matter lesions, may be less specific. The use of advanced MR imaging techniques is yielding further useful information regarding focal degeneration of the thalamus and optic radiation in NMOSD and suggests that paramagnetic rim patterns and changes in normal appearing white matter are specific to MS. MR imaging is crucial in the early recognition of NMOSD and in directing testing for AQP4 antibodies and guiding immediate acute treatment decisions. Increasingly, MR imaging is playing a role in diagnosing seronegative cases of NMOSD.

Correlations among disability, anti-AQP4 antibody status and prognosis in the spinal cord involved patients with NMOSD

Background

Neuromyelitis optica spectrum disorder (NMOSD) is a rare neuroinflammatory disorder of the central nervous system that typically involves the optic nerve, the spinal cord and other specific brain regions. In relapse of the disease, factors associated with clinical features and lesion severity are important for clinicians to predict disease-related disability.

Methods

We retrospectively analyzed 22 female patients with NMOSD who had spinal cord lesions. Detailed clinical features, onset symptoms, motor disability, relapse episodes, serum aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) autoantibodies and MRI characteristics were documented to correlate their associations with the nadir and three-month Expanded Disability Status Scale (EDSS) scores. Patients with three-month EDSS scores below four (< 4) were categorized as the good outcome group, while those with scores of four or more (> 4) were categorized as the poor outcome group.

Results

In patients with NMOSD, the mean age was 44.5 ± 12.8 years, and the mean three-month EDSS score was 4.3 ± 1.9. A significantly higher all-limb muscle power score was found in the good EDSS group than in the poor EDSS group (p = 0.01). A tendency toward longer follow-up periods and lower anti-AQP4 antibody levels was found in the good outcome group. Serum anti-AQP4 antibodies were present in 86% of patients with NMOSD, and MOG autoantibodies were found in one anti-AQP4 antibody-negative patient (33.3%). In patients with NMOSD, more than 40% of spinal cord lesions were distributed at the middle cervical and upper thoracic levels.

Conclusions

Our findings suggest that EDSS scores and MRC scores at the nadir had significant associations with three-month EDSS scores. The topographic distributions of the spinal cord lesions might relate to different serum anti-AQP4 antibody status. However, further studies will be needed to corroborate this finding.

Neuromyelitis optica spectrum disorders in Arabian Gulf (NMOAG); establishment and initial characterization of a patient registry

OBJECTIVE

To describe the clinical and radiological characteristics of neuromyelitis optica spectrum disorders (NMOSD) patients from the Arabian Gulf relative to anti-aquaporin 4 antibody serostatus.

METHODS

Retrospective multicentre study of hospital records of patients diagnosed with NMOSD based on 2015 International Panel on NMOSD Diagnosis (IPND) consensus criteria.

RESULTS

One hundred forty four patients were evaluated, 64.3% were anti-AQP4 antibody positive. Mean age at onset and disease duration were 31±12 and 7 ± 6 years respectively. Patients were predominantly female (4.7:1). Overall; relapsing course (80%) was more common than monophasic (20%). Optic neuritis was the most frequent presentation (48.6%), regardless of serostatus. The proportion of patients (54.3%) with visual acuity of ≤ 0.1 was higher in the seropositive group (p = 0.018). Primary presenting symptoms of transverse myelitis (TM) were observed in 29% of patients, and were the most significant correlate of hospitalization (p<0.001). Relative to anti-APQ4 serostatus, there were no significant differences in terms of age of onset, course, relapse rates or efficacy outcomes except for oligoclonal bands (OCB), which were more often present in seronegative patients (40% vs.22.5%; p = 0.054). Irrespective of serostatus, several disease modifying therapies were instituted including steroids or immunosuppressives, mostly, rituximab and azathioprine in the cohort irrespective of serostatus. The use of rituximab resulted in reduction in disease activity.

CONCLUSION

This is the first descriptive NMOSD cohort in the Arabian Gulf region. Seropositive patients were more prevalent with female predominance. Relapsing course was more common than monophasic. However, anti-AQP4 serostatus did not impact disease duration, relapse rate or therapeutic effectiveness. These findings offer new insights into natural history of NMOSD in patients of the Arabian Gulf and allow comparison with patient populations in different World regions.

A comparison between spinal cord infarction and neuromyelitis optica spectrum disorders: Clinical and MRI studies

This study aims to investigate the clinical features and magnetic resonance imaging (MRI) findings in patients with spinal cord infarction (SCI) and neuromyelitis optica spectrum disorders (NMOSDs). Over a period of 16 years, we retrospectively analyzed 39 patients with SCI and 21 patients with NMOSD. The demographic features and clinical presentations of both diseases were carefully documented. Etiology-specific MRI features, such as the length and distribution of the lesions, the owl's eyes sign and bright spotty lesions, were recorded and analyzed regarding their association with the clinical signs/symptoms. Patients with SCI were older than patients with NMOSD and had sudden onset of clinical symptoms with focal pain adjacent to the lesions. Concomitant spinal cord and vertebral body infarctions were frequently associated with aortic pathology (p = 0.04). In addition, artery dissection was highly associated with combined ASA and unilateral PSA infarctions and long segments of SCI (all p < 0.05). In contrast, patients with NMOSD had a relatively younger age of onset, female predominance and subacute progression of limbs weakness. As observed by MRI, the length and location of the lesions demonstrated significant differences between the two diseases (P < 0.01). The owl's eyes sign showed more frequently in patients with SCI than NMOSD (p < 0.01). The predicted prognoses in SCI and NMOSD were significantly associated with initial motor function (muscle power), after adjustments for age and gender (p < 0.01 and p = 0.02, respectively). Along with patient demographic characteristics, lesion features on MRI can help clinicians differentiate acute noncompressive myelopathy due to SCI from that due to NMOSD, which may lead to immediate initiation of adequate therapeutic measures.

The frequency of anti-aquaporin-4 Ig g antibody in neuromyelitis optica and its spectrum disorders at a single tertiary referral center in malaysia

Background. In the past the occurrence of neuromyelitis optica in Malaysia was thought to be uncommon and the frequency of anti-aquaporin-4 Ig G antibody was unknown. Objective. To evaluate the frequency of anti-aquaporin-4 Ig G antibody (Anti-AQP4 antibody) amongst patients with neuromyelitis optica (NMO) and its spectrum disorders (NMOSD) and the differences between the seropositive and seronegative groups. Methods. Retrospectively, 96 patients with NMO/high risk syndromes for NMOSD (HRS-NMOSD) were identified out of 266 patients with idiopathic inflammatory demyelinating disease from a single center hospital based registry. Anti-AQP4 seropositivity was found in 38/48 (79.2%) with NMO, 12/21 (57.1%) with brain involvement at high risk for NMOSD, 12/15 (80%) with transverse myelitis (i.e., 11/15 with relapsing transverse myelitis and one with monophasic transverse myelitis), and 3/7 (42.8%) with relapsing optic neuritis. Sixty-five out of 96 patients, that is, 67.7%, with NMO/HRS for NMOSD were seropositive. Seropositivity was significantly associated with female gender, a higher number of mean relapses, that is, 5.15 ± 4.42 versus 2.10 ± 1.68, longer length of spinal cord lesions, that is, 6.6 ± 4.9 versus 2.9 ± 2.5, vertebral bodies, higher EDSS, 4.5 ± 2.4 versus 2.4 ± 2.6, presence of paroxysmal tonic spasms, and blindness (unilateral/bilateral); P < 0.001. Longitudinally extensive cord lesions (contiguous or linear), presence of lesions in the cervical and thoracic regions, and involvement of the central gray matter or holocord regions on axial scans, were also significantly associated with seropositivity; P < 0.001. Conclusion. NMO and HRS for NMOSD are present in larger numbers than previously thought in Malaysia. More than 2/3rds are seropositive. Seropositive and seronegative NMO/NMOSD have differences that are useful in clinical practice.

Biomarkers for neuromyelitis optica

Neuromyelitis optica (NMO) is an acquired, heterogeneous inflammatory disorder, which is characterized by recurrent optic neuritis and longitudinally extensive spinal cord lesions. The discovery of the serum autoantibody marker, anti-aquaporin 4 (anti-AQP4) antibody, revolutionizes our understanding of pathogenesis of NMO. In addition to anti-AQP4 antibody, other biomarkers for NMO are also reported. These candidate biomarkers are particularly involved in T helper (Th)17 and astrocytic damages, which play a critical role in the development of NMO lesions. Among them, IL-6 in the peripheral blood is associated with anti-AQP4 antibody production. Glial fibrillary acidic protein (GFAP) in CSF demonstrates good correlations with clinical severity of NMO relapses. Detecting these useful biomarkers may be useful in the diagnosis and evaluation of disease activity of NMO. Development of compounds targeting these biomarkers may provide novel therapeutic strategies for NMO. This article will review the related biomarker studies in NMO and discuss the potential therapeutics targeting these biomarkers.

Poor responses to interferon-beta treatment in patients with neuromyelitis optica and multiple sclerosis with long spinal cord lesions

Interferon-beta (IFN-β) treatment may not be effective in neuromyelitis optica (NMO). Whether the poor response to IFN-β is related to long spinal cord lesions (LSCL) or the NMO disease entity itself is unclear. We evaluated the spinal cord involvement of patients with multiple sclerosis (MS) and NMO, as well as the response after receiving IFN-β. Forty-nine MS and 21 NMO patients treated with IFN-β for at least 2 years from 2002–2008 were enrolled in this study and the treatment response was analyzed 2 years post-treatment. In the study, spinal cord lesions were present in 57.1% (28/49) of the MS patients, of which 16.3% (8/49) presented spinal cord lesions longer than 3 vertebral segments (LSCL). Responses to IFN-β treatment were seen in 69.3% (34/49) of all the MS cases, of which the appropriate response rates were 76.1% (16/21) in MS patients without spinal cord lesions and 37.5% (3/8) in patients with LSCL. Only 14.2% (3/21) of NMO patients responded to IFN-β treatment. In conclusion, spinal cord lesion is common in MS patients in Taiwan. Both NMO and MS patients with LSCL had a poor response to IFN-β treatment. NMO patients had a worse response to IFN-β treatment than MS patients with LSCL, which shows that the crucial structural defect is something other than LSCL such as the elevated serum IL17 level in NMO compared to MS.

Utility of aquaporin-4 antibody assay in patients with neuromyelitis optica spectrum disorders

OBJECTIVE

Our aim was to evaluate the utility of aquaporin-4 antibodies (AQP4-Ab) in patients with neuromyelitis optica spectrum disorders (NMOSD).

METHODS

The clinical and radiological characteristics of 78 patients with NMOSD and 22 with multiple sclerosis (MS), who were tested for AQP4-Ab by a cell-based assay, were assessed.

RESULTS

The mean time interval between symptom onset and development of optic neuritis and myelitis was 39.9 months in neuromyelitis optica (NMO). About 40% of patients with limited NMO would have fulfilled the diagnostic criteria for MS in the absence of the antibody assay results. In patients with longitudinally extensive transverse myelitis, positive AQP4-Ab assay results were associated with the poor response to acute steroid treatment and asymptomatic visual evoked potential abnormality. Presence of either painful tonic spasm associated with myelitis or severe disability at onset had high specificity and relatively high sensitivity in differentiating NMOSD with AQP4-Ab from MS.

CONCLUSIONS

The AQP4-Ab assay can facilitate the early diagnosis of NMO and prevent limited NMO from being misdiagnosed as MS. It can predict the poor response to first-line acute-phase treatment and probably detect the subclinical optic nerve involvement in subgroups of NMOSD. Lastly, it will contribute to the upcoming revision of the current diagnostic criteria for NMO.

Quantitative assays for anti-aquaporin-4 antibody with subclass analysis in neuromyelitis optica

BACKGROUND

To clarify the clinical relevance of anti-aquaporin-4 (anti-AQP4) antibody titers and immunoglobulin (IgG) subclass.

METHODS

Using a bridging enzyme-linked immunosorbent assay (ELISA), a flow cytometric assay (FCMA) and an immunofluorescence assay (IFA) for anti-AQP4 antibodies, sera from 142 patients with multiple sclerosis (MS) as defined by the McDonald criteria (2005), 29 with neuromyelitis optica (NMO) who fulfilled the 1999 criteria, 19 with recurrent and/or longitudinally extensive myelitis (RM/LM), 86 with other non-inflammatory neurological diseases (OND) and 28 healthy controls (HC) were studied.

RESULTS

Anti-AQP4 antibody positivity rates by IFA, FCMA, and ELISA were 41.4%, 51.7% and 48.3%, respectively, in NMO (1999) patients, and 0% in the OND and HC groups. Twenty-six MS patients (18.3%) were positive for the antibody; 17 met the 2006 NMO criteria, including positivity for anti-AQP4 antibody, and five had longitudinally extensive myelitis (LM). Among the cases with anti-AQP4 antibody detected by FCMA, IgG1, 2, 3, and 4 anti-AQP4 antibodies were found in 97.8%, 37.0%, 6.5% and 6.5% respectively. There was no association of either antibody positivity or level of anti-AQP4 antibody IgG subclasses with clinical parameters after adjustment of p values for multiple comparisons.

CONCLUSIONS

FCMA and bridging ELISA are useful for detecting and quantifying anti-AQP4 antibodies.