Stage-dependent immunity orchestrates AQP4 antibody-guided NMOSD pathology: a role for netting neutrophils with resident memory T cells in situ.

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease of the CNS characterized by the production of disease-specific autoantibodies against aquaporin-4 (AQP4) water channels. Animal model studies suggest that anti-AQP4 antibodies cause a loss of AQP4-expressing astrocytes, primarily via complement-dependent cytotoxicity. Nonetheless, several aspects of the disease remain unclear, including: how anti-AQP4 antibodies cross the blood-brain barrier from the periphery to the CNS; how NMOSD expands into longitudinally extensive transverse myelitis or optic neuritis; how multiphasic courses occur; and how to prevent attacks without depleting circulating anti-AQP4 antibodies, especially when employing B-cell-depleting therapies. To address these knowledge gaps, we conducted a comprehensive 'stage-dependent' investigation of immune cell elements in situ in human NMOSD lesions, based on neuropathological techniques for autopsied/biopsied CNS materials. The present study provided three major findings. First, activated or netting neutrophils and melanoma cell adhesion molecule-positive (MCAM+) helper T (TH) 17/cytotoxic T (TC) 17 cells are prominent, and the numbers of these correlate with the size of NMOSD lesions in the initial or early-active stages. Second, forkhead box P3-positive (FOXP3+) regulatory T (Treg) cells are recruited to NMOSD lesions during the initial, early-active or late-active stages, suggesting rapid suppression of proinflammatory autoimmune events in the active stages of NMOSD. Third, compartmentalized resident memory immune cells, including CD103+ tissue-resident memory T (TRM) cells with long-lasting inflammatory potential, are detected under "standby" conditions in all stages. Furthermore, CD103+ TRM cells express high levels of granzyme B/perforin-1 in the initial or early-active stages of NMOSD in situ. We infer that stage-dependent compartmentalized immune traits orchestrate the pathology of anti-AQP4 antibody-guided NMOSD in situ. Our work further suggests that targeting activated/netting neutrophils, MCAM+ TH17/TC17 cells, and CD103+ TRM cells, as well as promoting the expansion of FOXP3+ Treg cells, may be effective in treating and preventing relapses of NMOSD.

B cells orchestrate tolerance to the neuromyelitis optica autoantigen AQP4.

Neuromyelitis optica is a paradigmatic autoimmune disease of the central nervous system, in which the water-channel protein AQP4 is the target antigen1. The immunopathology in neuromyelitis optica is largely driven by autoantibodies to AQP42. However, the T cell response that is required for the generation of these anti-AQP4 antibodies is not well understood. Here we show that B cells endogenously express AQP4 in response to activation with anti-CD40 and IL-21 and are able to present their endogenous AQP4 to T cells with an AQP4-specific T cell receptor (TCR). A population of thymic B cells emulates a CD40-stimulated B cell transcriptome, including AQP4 (in mice and humans), and efficiently purges the thymic TCR repertoire of AQP4-reactive clones. Genetic ablation of Aqp4 in B cells rescues AQP4-specific TCRs despite sufficient expression of AQP4 in medullary thymic epithelial cells, and B-cell-conditional AQP4-deficient mice are fully competent to raise AQP4-specific antibodies in productive germinal-centre responses. Thus, the negative selection of AQP4-specific thymocytes is dependent on the expression and presentation of AQP4 by thymic B cells. As AQP4 is expressed in B cells in a CD40-dependent (but not AIRE-dependent) manner, we propose that thymic B cells might tolerize against a group of germinal-centre-associated antigens, including disease-relevant autoantigens such as AQP4.

Elevated serum levels of bone morphogenetic protein-9 are associated with better outcome in AQP4-IgG seropositive NMOSD.

Lymphatic drainage in the central nervous system is regulated by meningeal lymphatic vasculature, and recurrent neuroinflammation alters lymphatic vessel remodeling. Patients with aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4 + NMOSD) were reported to demonstrate worse outcomes compared with patients with anti-myelin oligodendrocyte glycoprotein-associated disorders (MOGAD). This study aimed to investigate the serum cytokines relevant to vascular remodeling after attacks and their prognostic role in patients with AQP4 + NMOSD. This study measured the serum levels of 12 cytokines relevant to vascular remodeling, including bone morphogenetic protein-9 (BMP-9) and leptin, in 20 patients with AQP4 + NMOSD and 17 healthy controls (HCs). Disease controls included 18 patients with MOGAD. Serum and cerebrospinal fluid interleukin-6 levels were also measured. Clinical severity was evaluated with Kurtzke's Expanded Disability Status Scale (EDSS). Compared with HCs, patients with AQP4 + NMOSD showed higher BMP-9 (median; 127 vs. 80.7 pg/mL; P = 0.0499) and leptin levels (median; 16,081 vs. 6770 pg/mL; P = 0.0224), but not those with MOGAD. Better improvement in EDSS at 6 months was associated with baseline BMP-9 levels in patients with AQP4 + NMOSD (Spearman's rho = - 0.47; P = 0.037). Serum BMP-9 is upregulated at relapse and may contribute to vascular remodeling in AQP4 + NMOSD. Serum BMP-9 levels could predict clinical recovery 6 months after the attack.

Different immunological mechanisms between AQP4 antibody-positive and MOG antibody-positive optic neuritis based on RNA sequencing analysis of whole blood.

Purpose: To compare the different immunological mechanisms between aquaporin 4 antibody-associated optic neuritis (AQP4-ON) and myelin oligodendrocyte glycoprotein antibody-associated optic neuritis (MOG-ON) based on RNA sequencing (RNA-seq) of whole blood. Methods: Whole blood was collected from seven healthy volunteers, 6 patients with AQP4-ON and 8 patients with MOG-ON, and used for RNA-seq analysis. An examination of immune cell infiltration was performed using the CIBERSORTx algorithm to identify infiltrated immune cells. Results: RNA-seq analysis showed that the inflammatory signaling was mainly activated by TLR2, TLR5, TLR8 and TLR10 in AQP4-ON patients, while which was mainly activated by TLR1, TLR2, TLR4, TLR5 and TLR8 in MOG-ON patients. Biological function identification of differentially expressed genes (DEGs) based on Gene Ontology (GO) term and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis, as well as Disease Ontology (DO) analysis, showed that the inflammation in AQP4-ON was likely mediated by damage-associated molecular pattern (DAMP), while which in MOG-ON was likely mediated by pathogen-associated molecular pattern (PAMP). Analysis of immune cell infiltration showed that the proportion of immune cell infiltration was related to patients' vision. The infiltration ratios of monocytes (rs=0.69, P=0.006) and M0 macrophages (rs=0.66, P=0.01) were positively correlated with the BCVA (LogMAR), and the infiltration ratio of neutrophils was negatively correlated with the BCVA (LogMAR) (rs=0.65, P=0.01). Conclusion: This study reveals different immunological mechanisms between AQP4-ON and MOG-ON based on transcriptomics analysis of patients' whole blood, which may expand the current knowledge regarding optic neuritis.

Estimated prevalence of AQP4 positive neuromyelitis optica spectrum disorder and MOG antibody associated disease in São Paulo, Brazil.

BACKGROUND: Numerous studies addressed the prevalence of multiple sclerosis, but prevalence studies of NMOSD and, particularly, MOGAD are scarce. We aimed to estimate the prevalence of NMOSD and MOGAD in the city of São Paulo, based on the known prevalence of MS. METHODS: In this observational study, we determined the total number of patients with central nervous system demyelinating disease on regular follow-up in a university referral center in São Paulo, from May 2019 to May 2021 according to the diagnosis of multiple sclerosis (MS), NMOSD and MOGAD using the current diagnostic criteria for these diseases. We used the MS: NMOSD and MS: MOGAD ratios to estimate the ratio of these diseases in São Paulo, Brazil. RESULTS: We identified 968 patients with MS, 133 patients with AQP4 positive NMOSD, and 28 patients with MOGAD. We found the MS: NMOSD ratio of 7,28 and the MS: MOGAD ratio of 34,57. We estimated a prevalence of 2,1 per 100,000 inhabitants for NMOSD and of 0,4 per 100,000 inhabitants for MOGAD. CONCLUSION: The prevalence of NMOSD is high in São Paulo, but the prevalence of MOGAD is low when compared with the prevalence found in most of the studies reported to date.

Barriers to access and unmet needs to neuromyelitis optica spectrum disorders care in an Argentinean cohort.

INTRODUCTION: Neuromyelitis optica spectrum disorder (NMOSD) is a rare but severe neuroimmunological condition associated with a significant financial burden. NMOSD is also associated with increased health care utilization, including neurology outpatient visits, magnetic resonance imaging (MRI) use, long-term medication, among others. We aimed to evaluate real-world patient experiences in access to care and NMOSD burden in an Argentinean cohort. METHODS: This cross-sectional study used a self-administered survey and was conducted in Argentina (2022). Patients with NMOSD were divided into three groups: private health insurance (PHI), social health insurance (SHI), and public health insurance (PHI, Ministry of Public Health). Differences in access and health care barriers were assessed. RESULTS: One hundred patients with NMOSD (74 women) with a mean age at diagnosis of 38.7 years were included. Their EDSS was 2.8 and they were followed for 5.2 years. Of them, 51%, 11%, and 13% were employed (full-time: 57.5%), currently unemployed and retired by NMOSD, respectively. 55% of them visited between 2-3 specialists before NMOSD diagnosis. Aquaporin-4-antibody and/or myelin oligodendrocyte glycoprotein-antibody testing was requested in 91% (health insurance covered this partially in 15.3% and 32.9% of the time the test was entirely paid by patient/family). Patients with NMOSD receiving private medical care reported greater access to MRI, outpatient visits, and fewer issues to obtain NMOSD medications compared to those treated at public institutions. A longer mean time to MRI and neurology visit was found in the PHI group when compared with the other two subgroups. Regression analysis showed that private insurance (OR=3.84, p=0.01) was the only independent factor associated with appropriate access to NMOSD medications in Argentina. CONCLUSION: These findings suggest that barriers to access and utilization of NMOSD care services in Argentina are common. NMOSD patients experienced problems to receive NMOSD medication properly, especially those from the public sector.

A Comparison of Pediatric- and Adult-Onset Aquaporin-4 Immunoglobulin G-Positive Neuromyelitis Optica Spectrum Disorder: A Review of Clinical and Radiographic Characteristics.

BACKGROUND: The identification of immunoglobulin G antibodies against the aquaporin-4 channel (AQP-IgG) in the majority of adult patients differentiates neuromyelitis optica as a distinct disease entity. The high specificity of AQP4-IgG for neuromyelitis optica has allowed the identification of seropositive patients with atypical presentations of this disease. Neuromyelitis optica spectrum disorder has been increasingly recognized in children who demonstrate patterns of clinical involvement beyond the traditional boundaries of the optic pathways and spinal cord. METHODS: This is a single-center, retrospective review comparing demographic, clinical/paraclinical, and laboratory features of children and adults with a serologically confirmed diagnosis of AQP4-IgG-positive neuromyelitis optica spectrum disorder. RESULTS: Of 151 reviewed patient charts, 12 pediatric-onset and 31 adult-onset patients had AQP4-IgG-positive neuromyelitis optica spectrum disorder. The mean age of pediatric-onset neuromyelitis optica spectrum disorder was 12 ± 3.58 years with a female predilection (3:1). Pediatric patients showed more frequent involvement of the brainstem (6/12 [50%]); P = .008) and diencephalon (3/12 [25%]; P = .018). A preceding infection was identifiable in only 3 of 12 (25%) pediatric-onset patients. Moreover, disability as calculated on the expanded disability status scale was less severe in pediatric-onset cases compared to adult-onset cases in their most recent assessment (0 [0-9]) vs 6.5 [0-10]; P = .005). Pediatric-onset patients were also more likely to respond to treatment of acute episodes with corticosteroids ± intravenous immunoglobulin and/or plasmapheresis (Clinical Global Impression-Change scale: 2.5 [1-4] vs 4 [1-6], P = .009). INTERPRETATION: This retrospective study was able to compare and contrast pediatric- and adult-onset neuromyelitis optica spectrum disorder. Relative to their adult counterparts, pediatric-onset neuromyelitis optica spectrum disorder patients were more likely to respond to treatment and less likely to be disabled from their disease at follow-up. Therefore, pediatric-onset disease may represent a less virulent form of neuromyelitis optica spectrum disorder.

Bilateral parafalcine cortical and leptomeningeal impairment in MOG antibody disease and AQP4 neuromyelitis optica.

OBJECTIVE: Bilateral parafalcine cortical and leptomeningeal impairment (BPCLI) is a rare finding observed in cases of myelin oligodendrocyte glycoprotein (MOG) antibody disease (MOGAD) and neuromyelitis optica spectrum disorders (NMOSD). The failure to recognize BPCLI may lead to misdiagnosis and delayed treatment. This study aimed to delineate the clinical and imaging characteristics of patients with BPCLI. METHODS: Clinical data from a cohort of 366 patients diagnosed with NMOSD or MOGAD were retrospectively reviewed. Subsequently, the clinical features of the seven patients with BPCLI were analyzed. RESULTS: Of the 366 patients, 33 had MOGAD, whereas 264 were positive for antibodies (Abs) against aquaporin-4 (AQP4) and had NMOSD. BPCLI was detected in five patients (15.1%) with MOGAD and two patients (0.7%) with AQP4-Ab-positive NMOSD. All seven patients (four males) presented with meningoencephalitis-like symptoms at the time of BPCLI. Six patients had seizures, and three of them also presented with fever. Three patients were misdiagnosed with intracranial infection, and one was misdiagnosed with cerebral venous thrombosis. Analysis of the cerebrospinal fluid revealed elevated total protein levels in two patients and increased leukocyte counts in five. In addition to BPCLI, impairments in the hippocampus and corpus callosum were confirmed in one and four patients, respectively. Moreover, five patients exhibited meningeal enhancement, and two showed callosal enhancement. In all cases, BPCLI attacks responded well to high-dose methylprednisolone or immunoglobulin therapy. CONCLUSIONS: BPCLI can be observed in both MOGAD and AQP4 NMOSD. It appears to be characteristic of MOGAD but is relatively rare in AQP4 NMOSD. These findings should be noted to avoid misdiagnosis.

Comparison of neutrophil-to-lymphocyte ratio between myelin oligodendrocyte glycoprotein antibody-associated disease and aquaporin-4 antibody-positive neuromyelitis optica spectrum disorders in adults.

The neutrophil-to-lymphocyte ratio (NLR) is a biomarker for evaluating disease activity in systemic autoimmune diseases. However, few studies have discussed NLR changes in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). This study aimed to explore the NLR difference between MOGAD, aquaporin-4 antibody (AQP4-Ab)-positive neuromyelitis optica spectrum disorders (NMOSD), and healthy controls (HCs) and evaluate the clinical value of NLR in the differential diagnosis. We included 15 patients with MOGAD, 28 patients with AQP4-Ab-positive NMOSD, and 68 HCs. Their NLRs were calculated, and statistical analysis was performed, with statistical significance set at P < 0.05. In pairwise comparisons between three groups, P < 0.017 was considered statistically significant under Bonferroni correction. NLR was higher during the acute attack in MOGAD patients than HCs but lower than in AQP4-Ab-positive NMOSD patients. NLR was correlated with Expanded Disability Status Scale (EDSS) in MOGAD and AQP4-Ab-positive NMOSD patients. Also, there were no statistical differences in intracranial pressure between MOGAD and AQP4-Ab-positive NMOSD patients and HCs. The cut-off value was 2.86, and the sensitivity and specificity were 0.750 and 0.867, respectively. In conclusion, our results suggest that NLR may be a helpful marker to evaluate disease severity and differentiate between both diseases at a cut-off value of > 2.86 when patients have clinical symptoms like optic neuritis or myelitis.

ABCB1 gene polymorphisms impact the effect of high-dose intravenous methylprednisolone therapy on optic neuritis associated with AQP4-IgG-positive neuromyelitis optica spectrum disorder.

WHAT IS KNOWN AND OBJECTIVE: Patients with optic neuritis (ON) have significant individual differences in their response to high-dose intravenous methylprednisolone (HIMP) therapy. This study aims to evaluate the association between gene polymorphisms and the efficacy of HIMP therapy in Chinese Han patients with ON mediated by aquaporin-4 immunoglobulin G antibody (AQP4-IgG) -positive neuromyelitis optica spectrum disorder (NMOSD) or multiple sclerosis (MS). METHODS: Chinese Han patients with AQP4-IgG+ NMOSD-ON or MS-ON were genotyped for four candidate genes: ABCB1 (rs1045642, rs1128503, rs2032582), NR3C1 (rs41423247), TBX21 (rs9910408, rs16947078) and VDR (rs731236, rs1544410, rs7975232, rs2228570). Patients were divided into glucocorticoid resistance (GR) and glucocorticoid sensitivity (GS) groups based on vision acuity (VA) improvement after HIMP treatment. Intergroup comparisons were performed on clinical characteristics, allele and genotype frequencies and haplotype distributions. RESULTS: A total of 267 patients completed the follow-up, including 120 patients with AQP4-IgG+ NMOSD-ON and 147 patients with MS-ON. We observed a significant association between the ABCB1 G2677T/A (rs2032582) polymorphism and glucocorticoid response in AQP4-IgG+ NMOSD-ON patients. Changes in VA scores in patients with the GG genotype were significantly lower than those in patients with the T/A T/A genotype (1.07 ± 1.20 vs. 1.77 ± 1.31, p = 0.026). In the GS group, the G allele had a lower frequency than the T/A allele (32.03% vs. 60.16%, p = 0.001). Logistic regression analysis showed that the G2677T/A GG and G T/A genotypes could increase the GR risk 3.53 and 2.67 times compared with the T/A T/A genotype, respectively (OR = 3.534, 95% CI: 1.186-10.527, p = 0.023; OR = 2.675, 95% CI: 1.005-7.123, p = 0.049). In addition, haplotype analysis showed that AQP4-IgG+ NMOSD-ON patients with the TAT/TTT haplotype (ABCB1 C3435T-G2677T/A-C1236T) were only 0.54 times more likely to develop GR than those with other haplotypes (OR = 0.542, 95% CI: 0.315-0.932, p = 0.026). However, we did not observe intergroup differences in the MS-ON population. WHAT IS NEW AND CONCLUSION: Our findings suggest that the G > T/A polymorphism of ABCB1 G2677T/A and the TAT/TTT haplotype played a protective role in HIMP treatment of AQP4-IgG+ NMOSD-ON but not MS-ON.

Expression and Clinical Correlation Analysis Between Repulsive Guidance Molecule a and Neuromyelitis Optica Spectrum Disorders.

Objectives: This study sought to explore the expression patterns of repulsive guidance molecules a (RGMa) in neuromyelitis optica spectrum disorders (NMOSD) and to explore the correlation between RGMa and the clinical features of NMOSD. Methods: A total of 83 NMOSD patients and 22 age-matched healthy controls (HCs) were enrolled in the study from October 2017 to November 2021. Clinical parameters, including Expanded Disability Status Scale (EDSS) score, degree of MRI enhancement, and AQP4 titer were collected. The expression of serum RGMa was measured by enzyme-linked immunosorbent assay (ELISA) and compared across the four patient groups. The correlation between serum RGMa levels and different clinical parameters was also assessed. Results: The average serum expression of RGMa in the NMOSD group was significantly higher than that in the HC group (p < 0.001). Among the patient groups, the acute phase group exhibited significantly higher serum RGMa levels than did the remission group (p < 0.001). A multivariate analysis revealed a significant positive correlation between RGMa expression and EDSS score at admission, degree of MRI enhancement, and segmental length of spinal cord lesions. There was a significant negative correlation between the expression of RGMa in NMOSD and the time from attack to sampling or delta EDSS. Conclusions: The current study suggests that RGMa may be considered a potential biomarker predicting the severity, disability, and clinical features of NMOSD.

Free-water diffusion tensor imaging detects occult periependymal abnormality in the AQP4-IgG-seropositive neuromyelitis optica spectrum disorder.

To compare free-water corrected diffusion tensor imaging (DTI) measures in the normal-appearing periependymal area between AQP4-IgG-seropositive NMOSD and multiple sclerosis (MS) to investigate occult pathophysiology. This prospective study included 44 patients (mean age, 39.52 ± 11.90 years; 14 men) with AQP4-IgG-seropositive NMOSD (n = 20) and MS (n = 24) who underwent DTI between April 2014 and April 2020. Based on free-water corrected DTI measures obtained from normal-appearing periependymal voxels of (1) lateral ventricles and (2) the 3rd and 4th ventricles as dependent variables, MANCOVA was conducted to compare the two groups, using clinical variables as covariates. A significant difference was found between AQP4-IgG-seropositive NMOSD and MS in the 3rd and 4th periependymal voxels (λ = 0.462, P = 0.001). Fractional anisotropy, axial diffusivity was significantly decreased and radial diffusivity was increased in AQP4-IgG-seropositive NMOSD in post-hoc analysis, compared with MS (F = 27.616, P < 0.001, F = 7.336, P = 0.011, and F = 5.800, P = 0.022, respectively). Free-water corrected DTI measures differ in the periependymal area surrounding the diencephalon and brain stem/cerebellum between MS and NMOSD, which may suggest occult white matter injury in areas with distribution of AQP-4 in NMOSD.

[A patient with multiple sclerosis who developed bilateral optic neuritis and central trigeminal myelin lesion].

A 70-year-old woman was admitted to our hospital due to bilateral optic neuritis and left facial sensory disturbance that became exacerbated over 10 days. Both serum and cerebrospinal fluid (CSF) were negative for aquaporin 4 antibody and myelin oligodendrocyte glycoprotein antibody. A high level of myelin basic protein (MBP) in her CSF was observed. Brain MRI showed a high T2 signal and contrast enhancement of the bilateral optic nerve, intramedullary tract and central myelin lesion in the trigeminal nerve. After intravenous methylprednisolone pulse therapy, her visual impairment and facial sensory disturbance gradually improved. She was diagnosed with clinically isolated syndrome, based on 2017 McDonald criteria. A diagnosis of multiple sclerosis (MS) was suspected due to the trigeminal myelin lesion confined to the central myelin portion and high level of MBP in the CSF. Treatment with dimethyl fumarate has been effective for preventing recurrence in 13 months in this patient. The central-peripheral myelin transitional zone at the trigeminal nerve is located 1-6 mm from the pons, where central myelin changes to the peripheral myelin. This patient showed a high T2 signal at the trigeminal nerve 3 mm from the pons on MRI, suggesting the involvement of a central trigeminal myelin lesion. Findings of a central trigeminal myelin lesion on MRI may aid in differentiating between MS and seronegative neuromyelitis optica spectrum disorder.

High cell surface expression and peptide binding affinity of HLA-DQA1*05:03, a susceptible allele of neuromyelitis optica spectrum disorders (NMOSD).

Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing autoimmune disease characterized by the presence of pathogenic autoantibodies, anti-aquaporin 4 (AQP4) antibodies. Recently, HLA-DQA1*05:03 was shown to be significantly associated with NMOSD in a Japanese patient cohort. However, the specific mechanism by which HLA-DQA1*05:03 is associated with the development of NMOSD has yet to be elucidated. In the current study, we revealed that HLA-DQA1*05:03 exhibited significantly higher cell surface expression levels compared to other various DQA1 alleles, and that its expression strongly depended on the amino acid sequence of the α1 domain, with a preference for leucine at position 75. Moreover, in silico analysis indicated that the HLA-DQ encoded by HLA-DQA1*05:03 preferentially presents immunodominant AQP4 peptides, and that the peptide major histocompatibility complexes (pMHCs) are more energetically stable in the presence of HLA-DQA1*05:03 than other HLA-DQA1 alleles. In silico 3D structural models were also applied to investigate the validity of the energetic stability of pMHCs. Taken together, our findings indicate that HLA-DQA1*05:03 possesses a distinct property to play a pathogenic role in the development of NMOSD.

Interleukin-6 Receptor Blockade in Treatment-Refractory MOG-IgG-Associated Disease and Neuromyelitis Optica Spectrum Disorders.

BACKGROUND AND OBJECTIVES: To evaluate the long-term safety and efficacy of tocilizumab (TCZ), a humanized anti-interleukin-6 receptor antibody in myelin oligodendrocyte glycoprotein-IgG-associated disease (MOGAD) and neuromyelitis optica spectrum disorders (NMOSD). METHODS: Annualized relapse rate (ARR), Expanded Disability Status Scale score, MRI, autoantibody titers, pain, and adverse events were retrospectively evaluated in 57 patients with MOGAD (n = 14), aquaporin-4 (AQP4)-IgG seropositive (n = 36), and seronegative NMOSD (n = 7; 12%), switched to TCZ from previous immunotherapies, particularly rituximab. RESULTS: Patients received TCZ for 23.8 months (median; interquartile range 13.0-51.1 months), with an IV dose of 8.0 mg/kg (median; range 6-12 mg/kg) every 31.6 days (mean; range 26-44 days). For MOGAD, the median ARR decreased from 1.75 (range 0.5-5) to 0 (range 0-0.9; p = 0.0011) under TCZ. A similar effect was seen for AQP4-IgG+ (ARR reduction from 1.5 [range 0-5] to 0 [range 0-4.2]; p < 0.001) and for seronegative NMOSD (from 3.0 [range 1.0-3.0] to 0.2 [range 0-2.0]; p = 0.031). During TCZ, 60% of all patients were relapse free (79% for MOGAD, 56% for AQP4-IgG+, and 43% for seronegative NMOSD). Disability follow-up indicated stabilization. MRI inflammatory activity decreased in MOGAD (p = 0.04; for the brain) and in AQP4-IgG+ NMOSD (p < 0.001; for the spinal cord). Chronic pain was unchanged. Regarding only patients treated with TCZ for at least 12 months (n = 44), ARR reductions were confirmed, including the subgroups of MOGAD (n = 11) and AQP4-IgG+ patients (n = 28). Similarly, in the group of patients treated with TCZ for at least 12 months, 59% of them were relapse free, with 73% for MOGAD, 57% for AQP4-IgG+, and 40% for patients with seronegative NMOSD. No severe or unexpected safety signals were observed. Add-on therapy showed no advantage compared with TCZ monotherapy. DISCUSSION: This study provides Class III evidence that long-term TCZ therapy is safe and reduces relapse probability in MOGAD and AQP4-IgG+ NMOSD.

Clinical burden of relapses in aquaporin-4 immunoglobulin G-positive neuromyelitis optica spectrum disorder: A single center cohort analysis.

A retrospective, observational analysis of 47 patients with aquaporin-4 immunoglobulin G-positive neuromyelitis optica spectrum disorder (AQP4-IgG+ NMOSD) enrolled at the University of Utah healthcare system was conducted. Visual acuity, neurological disability, and pain medication use were compared in relapsing versus non-relapsing patients. The median observation period was 3.6 years (range: 0.0-11.4 years); the annual relapse rate was 0.1376 (95% confidence interval: 0.0874, 0.191). Relapsing patients (n = 14) exhibited diminished visual acuity, clinically meaningful worsening of neurological disability, and greater pain medication use than non-relapsing patients (n = 33). Therapies that reduce the risk of relapses should be considered when making treatment decisions.

Comparative study of AQP4-NMOSD, MOGAD and seronegative NMOSD: a single-center Belgian cohort.

PURPOSE: To emphasize physio-pathological, clinical and prognosis differences between conditions causing serious and sometimes very similar clinical manifestations: anti-aquaporin-4 (AQP4) and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies related diseases, and seronegative NMOSD (neuromyelitis optica spectrum disorders). METHODS: Based on Wingerchuk et al. (Neurology 85:177-189, 2015) criteria for NMOSD and on those more recently proposed by Jarius et al. (J Neuroinflammation 15:134, 2018) for MOGAD (MOG associated disorders), we retrospectively surveyed 10 AQP4-NMOSD, 8 MOGAD and 2 seronegative NMOSD, followed at the specialized neuroimmunology unit of the CHU Liège. RESULTS: Female predominance was only observed in AQP4 group. Age at onset was 37.8 and 27.7 years old for AQP4-NMOSD and MOGAD respectively. In both groups, the first clinical event most often consisted of optic neuritis (ON), followed by isolated myelitis. Fifteen of our 20 patients encountered a relapsing course with 90% relapses in AQP4-NMOSD, 62.5% in MOGAD and 50% in seronegative group, and a mean period between first and second clinical event of 7.1 and 4.8 months for AQP4-NMOSD and MOGAD, respectively. In total we counted 54 ON, with more ON per patient in MOGAD. MOG-associated ON mainly affected the anterior part of the optic nerve with a papilledema in 79.2% of cases. Despite a fairly good visual outcome after MOG-associated ON, retinal nerve fibre layer (RNFL) thickness decreased, suggesting a fragility of the optic nerve toward further attacks. CONCLUSION: As observed in larger cohorts, our MOGAD and AQP4-NMOSD cases differ by clinical and prognostic features. A better understanding of these diseases should encourage prompt biological screening and hasten proper diagnosis and treatment.

Comparative analysis of clinical and imaging data between patients with myelin oligodendrocyte glycoprotein antibody disease and patients with aquaporin 4 antibody-positive neuromyelitis optica spectrum disorder.

BACKGROUND: We aimed to compare the clinical data, laboratory findings, and imaging characteristics of myelin oligodendrocyte glycoprotein antibody disease (MOGAD) and aquaporin 4 antibody (AQP4)-positive neuromyelitis optica spectrum disorder (NMOSD), as detailed comparative analyses of laboratory data for both diseases are rare. METHODS: Our retrospective study compared the clinical data, laboratory findings, and imaging characteristics of 118 AQP4-positive patients with first-episode NMOSD and 25 patients with first-episode MOGAD. Logistic regression was used to determine the factors that differentiated MOGAD and AQP4-positive NMOSD. RESULTS: There were significant differences in age, symptoms, recurrence rate, laboratory indicators, and imaging examinations between patients with MOGAD and patients with AQP4-positive NMOSD. Patients with MOGAD were younger and had higher levels of uric acid than those with AQP4-positive NMOSD. The proportion of cortical gray matter/juxtacortical white matter lesions was significantly higher in the MOGAD group than in the NMOSD group. Logistic regression revealed that young age [odds ratio (OR) = 0.947, 95% confidence interval (CI) = 0.905-0.99], high uric acid level (OR = 1.016, 95% CI = 1.006-1.027), and cortical gray matter/juxtacortical white matter involvement (OR = 3.889, 95% CI = 1.048-14.442) were significantly related to MOGAD. CONCLUSION: The multivariate analysis of the present study demonstrated that age, uric acid level, and the presence of lesions in the cortical gray matter/juxtacortical white matter can aid in distinguishing patients with AQP4-positive NMOSD from those with MOGAD. These factors may also aid in determining which patients should be tested for antibodies.

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.