Administration methods and dosage of poly(lactic acid)-glycol intervention to myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalitis mice.

BACKGROUND: Myelin oligodendrocyte glycoprotein-associated disorders (MOGAD) is an autoimmune central nervous system disease. Antigen-specific immune tolerance using nanoparticles such as Polylactic-co-glycolic acid (PLGA) have recently been used as a new therapeutic tolerization approach for CNS autoimmune diseases. We examined whether MOG1-125 conjugated with PLGA could induce MOG-specific immune tolerance in an experimental autoimmune encephalitis (EAE) mouse model. EAE was induced in sixty C57BL/6 J wild-type mice using MOG1-125 peptide with complete Freund's Adjuvant. The mice were divided into 12 groups (n = 5 each) to test the ability of MOG1-125 conjugated PLGA intervention to mitigate the severity or improve the outcomes from EAE with and without rapamycin compared to antigen alone or PLGA alone. EAE score and serum MOG-IgG titers were compared among the interventions.Kindly check and confirm the processed Affiliation “4” is appropriate.I confirmed the Aff 4.Affiliation: Corresponding author information have been changed to present affiliation. Kindly check and confirm.I checked and confirmed the Corresponding author's information. RESULTS: Mice with EAE that were injected intraperitoneally with MOG1-125 conjugated PLGA + rapamycin complex showed dose-dependent mitigation of EAE score. Intraperitoneal and intravenous administration resulted in similar clinical outcomes, whereas 80% of mice treated with subcutaneous injection had a recurrence of clinical score worsening after approximately 1 week. Although there was no significant difference in EAE scores between unconjugated-PLGA and MOG-conjugated PLGA, serum MOG-IgG tended to decrease in the MOG-conjugated PLGA group compared to controls. CONCLUSION: Intraperitoneal administration of PLGA resulted in dose-dependent and longer-lasting immune tolerance than subcutaneous administration. The induction of immune tolerance using PLGA may represent a future therapeutic option for patients with MOGAD.

Anti-aquaporin-4 immune complex stimulates complement-dependent Th17 cytokine release in neuromyelitis optica spectrum disorders.

Proinflammatory cytokines, such as (IL: interleukin) IL-6 and IL-17A, and complement fixation are critical in the immunopathogenesis of neuromyelitis optica spectrum disorders (NMOSD). Blocking the IL-6 receptor or the C5 complement pathway reduces relapse risk. However, the role of interleukin (IL)-6 and complement in aquaporin-4 (AQP4) autoimmunity remains unclear. To investigate the role of the anti-AQP4 immunoglobulin (AQP4-IgG)/AQP4 immunocomplex on the induction and profile of ex vivo cytokine and surface marker expression in peripheral blood mononuclear cells (PBMC) culture. Isolated PBMCs obtained from 18 patients with AQP4-IgG-seropositive-NMOSD (8 treatment-naive, 10 rituximab-treated) or ten healthy controls were cultured with AQP4-immunocomplex with or without complement. Changes in PBMC surface markers and cytokine expression were profiled using flow cytometry and ELISA. PBMCs derived from treatment-naive NMOSD patients stimulated with a complex mixture of serum complement proteins produced significant elevations of IL-17A and IL-6. Rituximab-treated patients also exhibited higher IL-6 but not IL-17A release. IL-6 and IL-17A elevations are not observed without complement. Co-stimulation of PBMCs with AQP4-IgG/AQP4 immunocomplex and complement prompts a Th17-biased response consistent with the inflammatory paradigm observed in NMOSD. A possible inflammation model is proposed via antigen-specific autoreactive peripheral blood cells, including NK/NKT cells.

Peripheral MC1R Activation Modulates Immune Responses and is Neuroprotective in a Mouse Model of Parkinson's Disease.

BACKGROUND: Melanocortin 1 receptor (MC1R) is a key pigmentation gene, and loss-of-function of MC1R variants that produce red hair may be associated with Parkinson's disease (PD). We previously reported compromised dopaminergic neuron survival in Mc1r mutant mice and dopaminergic neuroprotective effects of local injection of a MC1R agonist to the brain or a systemically administered MC1R agonist with appreciable central nervous system (CNS) permeability. Beyond melanocytes and dopaminergic neurons, MC1R is expressed in other peripheral tissues and cell types, including immune cells. The present study investigates the impact of NDP-MSH, a synthetic melanocortin receptor (MCR) agonist that does not cross BBB, on the immune system and the nigrostriatal dopaminergic system in mouse model of PD. METHODS: C57BL/6 mice were treated systemically with MPTP.HCl (20 mg/kg) and LPS (1 mg/kg) from day 1 to day 4 and NDP-MSH (400 µg/kg) or vehicle from day 1 to day 12 following which the mice were sacrificed. Peripheral and CNS immune cells were phenotyped and inflammatory markers were measured. The nigrostriatal dopaminergic system was assessed behaviorally, chemically, immunologically, and pathologically. To understand the role of regulatory T cells (Tregs) in this model, CD25 monoclonal antibody was used to deplete CD25 + Tregs. RESULTS: Systemic NDP-MSH administration significantly attenuated striatal dopamine depletion and nigral dopaminergic neuron loss induced by MPTP + LPS. It improved the behavioral outcomes in the pole test. Mc1r mutant mice injected with NDP-MSH in the MPTP and LPS paradigm showed no changes in striatal dopamine levels suggesting that the NDP-MSH acts through the MC1R pathway. Although no NDP-MSH was detected in the brain, peripheral, NDP-MSH attenuated neuroinflammation as observed by diminished microglial activation in the nigral region, along with reduced TNF-α and IL1ß levels in the ventral midbrain. Depletion of Tregs was associated with diminished neuroprotective effects of NDP-MSH. CONCLUSIONS: Our study demonstrates that peripherally acting NDP-MSH confers protection on dopaminergic nigrostriatal neurons and reduces hyperactivated microglia. NDP-MSH modulates peripheral immune responses, and Tregs may be involved in the neuroprotective effect of NDP-MSH.

Progression independent of relapses in aquaporin4-IgG-seropositive neuromyelitis optica spectrum disorder, myelin oligodendrocyte glycoprotein antibody-associated disease, and multiple sclerosis.

OBJECTIVES: To determine whether progression independent of relapse activity (PIRA) is present in Aquaporin4-IgG-seropositive neuromyelitis optica spectrum disorder (AQP4+NMOSD), Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and relapsing remitting Multiple sclerosis (RRMS). METHODS: We retrospectively studied the change in EDSS, confirmed disability worsening (CDW) (i.e., PIRA), and new MRI lesions in AQP4+NMOSD, and MOGAD and MS patients. Linear mixed-effect regression model was used to compare the longitudinal changes in EDSS, and Cox regression was used to compare changes in MRI. RESULTS: The estimated mean ΔEDSS in the AQP4+NMOSD and matched MS group were +0.06 (95%CI: -0.40, +0.52, p = 0.76), and +0.02 (95%CI: -0.05, +0.08, p = 0.6) respectively. The same estimate was -0.08 (95%CI: -0.18, +0.02, p = 0.12) in MOGAD and +0.05 (95%CI: -0.05, +0.15, p = 0.35) in matched MS group. Comparing groups for the presence of CDW (i.e., PIRA) showed that PIRA is more associated with MS compared to AQP4+NMOSD (p = 0.02) and MOGAD (p<0.001). Compared to their matched MS groups, the annualized rate of PIRA was significantly lower in AQP4 (0.08 vs 0.44; p<0.0001), and MOG groups (0.04 vs 0.13; p<0.0001). New T2 or enhancing lesions on brain MRI were higher in MS compared to AQP4+NMOSD and MOGAD patients. CONCLUSION: Relapse-independent changes in the EDSS, CDW, and MRI activity are not common in AQP4+NMOSD and MOGAD, especially when compared with MS. Since our patients were on relapse prevention therapies at the time of EDSS measurements, our study supports the importance of preventing relapses in AQP4+NMOSD and MOGAD and suggests different pathologic mechanisms of relapse-free neurological damage between MS and AQP4+NMOSD/MOGAD.

Peripheral MC1R activation modulates immune responses and is neuroprotective in a mouse model of Parkinson's disease.

Background: Melanocortin 1 receptor (MC1R) is a key pigmentation gene, and loss-of-function of MC1R variants that produce red hair may be associated with Parkinson's disease (PD). We previously reported compromised dopaminergic neuron survival in Mc1r mutant mice and dopaminergic neuroprotective effects of local injection of a MC1R agonist to the brain or a systemically administered MC1R agonist with appreciable CNS permeability. Beyond melanocytes and dopaminergic neurons, MC1R is expressed in other peripheral tissues and cell types, including immune cells. The present study investigates the impact of NDP-MSH, a synthetic melanocortin receptor (MCR) agonist that does not cross BBB, on the immune system and the nigrostriatal dopaminergic system in mouse model of PD. Methods: C57BL/6 mice were treated systemically with MPTP.HCl (20 mg/kg) and LPS (1 mg/kg) from day 1 to day 4 and NDP-MSH (400 µg/kg) or vehicle from day 1 to day 12 following which the mice were sacrificed. Peripheral and CNS immune cells were phenotyped and inflammatory markers were measured. The nigrostriatal dopaminergic system was assessed behaviorally, chemically, immunologically, and pathologically. To understand the role of regulatory T cells (Tregs) in this model, CD25 monoclonal antibody was used to deplete CD25+ Tregs. Results: Systemic NDP-MSH administration significantly attenuated striatal dopamine depletion and nigral dopaminergic neuron loss induced by MPTP+LPS. It improved the behavioral outcomes in the pole test. Mc1r mutant mice injected with NDP-MSH in the MPTP and LPS paradigm showed no changes in striatal dopamine levels suggesting that the NDP-MSH acts through the MC1R pathway. Although no NDP-MSH was detected in the brain, peripheral, NDP-MSH attenuated neuroinflammation as observed by diminished microglial activation in the nigral region, along with reduced TNF-α and IL1ß levels in the ventral midbrain. Depletion of Tregs limited the neuroprotective effects of NDP-MSH. Conclusions: Our study demonstrates that peripherally acting NDP-MSH confers protection on dopaminergic nigrostriatal neurons and reduces hyperactivated microglia. NDP-MSH modulates peripheral immune responses, and Tregs may be involved in the neuroprotective effect of NDP-MSH.

Electrophysiological and Histological Correlations of Optic Neuritis in the Dark Agouti Rat Model of Experimental Autoimmune Encephalomyelitis.

Experimental autoimmune encephalomyelitis (EAE) is an animal model of Inflammatory central nervous system (CNS) disease. Dark agouti (DA) rats immunized with full-length myelin oligodendrocyte glycoprotein (MOG1-125) typically develop a relapsing-remitting EAE form characterized by predominant demyelinating involvement of the spinal cord and optic nerve. Visually evoked potentials (VEP) are a useful objective tool to assess the optic nerve function and monitor electrophysiological changes in optic neuritis (ON). The current study aimed to assess the VEP changes in MOG-EAE DA rats using a minimally invasive recording device and to correlate them with histological findings. Twelve MOG-EAE DA rats and four controls underwent VEP recording at day 0, 7, 14, 21, and 28 post-EAE induction. Tissue samples were obtained on days 14, 21, and 28 from two EAE rats and one control. The median VEP latencies were significantly higher on days 14, 21, and 28 compared to baseline, with maximal latencies observed on day 21. The histological analyses on day 14 demonstrated inflammation with largely preserved myelin and axonal structures. Inflammation and demyelination with largely preserved axons were evident on days 21 and 28, which correlated with prolonged VEP latencies. These findings suggest that VEPs may be a reliable biomarker reflecting the optic nerve involvement in EAE. Moreover, the use of a minimally invasive device enables observation of VEP changes over time in MOG-EAE DA rats. Our findings may have important implications for testing the potential neuroprotective and regenerative effects of new therapies for CNS demyelinating diseases.

White blood cell count profiles in anti-aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorder and anti-myelin oligodendrocyte glycoprotein antibody-associated disease.

White blood cell (WBC) count profiles in anti-aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) and anti-myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are still unknown. This study evaluated the total WBC count, differential WBC counts, monocyte-to-lymphocyte ratio (MLR), and neutrophil-to-lymphocyte ratio (NLR) in patients with these diseases within three months from an attack before acute treatment or relapse prevention and compared the profiles with those in matched volunteers or in multiple sclerosis (MS) patients. AQP4-NMOSD patients (n = 13) had a higher neutrophil count (p = 0.0247), monocyte count (p = 0.0359), MLR (p = 0.0004), and NLR (p = 0.0037) and lower eosinophil (p = 0.0111) and basophil (p = 0.0283) counts than those of AQP4-NMOSD-matched volunteers (n = 65). Moreover, patients with MOGAD (n = 26) had a higher overall WBC count (p = 0.0001), neutrophil count (p < 0.0001), monocyte count (p = 0.0191), MLR (p = 0.0320), and NLR (p = 0.0002) than those of MOGAD-matched volunteers (n = 130). The three demyelinating diseases showed similar levels of the total and differential WBC counts; however, MOGAD and MS showed different structures in the hierarchical clustering and distributions on a two-dimensional canonical plot using differential WBC counts from the other three groups. WBC count profiles were similar in patients with MOGAD and MS but differed from profiles in matched volunteers or patients with AQP4-NMOSD.

Development of Paraneoplastic Neuromyelitis Optica after Lung Resection in a Patient with Squamous Cell Carcinoma.

Neurological paraneoplastic syndrome is a relatively rare condition in patients with malignant tumors. Recently, it has been reported that anti-Aquaporin 4 (AQP4) antibody is highly specific for neuromyelitis optica. The patient was a 76-year-old man. He underwent right upper lobectomy for squamous cell carcinoma of the lung. Although the immediate postoperative course was uneventful, neurological symptoms became apparent from postoperative day (POD) 4. Magnetic resonance imaging showed longitudinally extended edematous lesions in the spinal cord, and a cerebrospinal fluid examination was positive for anti-AQP4 antibody, leading to the diagnosis of paraneoplastic neuromyelitis optica. Despite multiple rounds of steroid pulse therapy and plasma exchange, the neurological symptoms worsened and the patient died on POD 46. The development of neuromyelitis optica in the early postoperative period could be related to the influence of surgical stress or epidural anesthesia.

Upregulated complement receptors correlate with Fc gamma receptor 3A-positive natural killer and natural killer-T cells in neuromyelitis optica spectrum disorder.

BACKGROUND AND OBJECTIVES: Inhibition of terminal complement in neuromyelitis optica spectrum disorder (NMOSD) using eculizumab helps prevent relapses, but the exact mechanism of action of the drug remains unclear. Similarly, genetic variants in the Fc Gamma receptor 3A (FCGR3A), also known as CD16, are correlated with outcomes in NMOSD, but the immune cells expressing those CD16 are unknown. We compared CD16 expression on immune cells modulated by complement activity in natural killer (NK) cells and natural killer-T (NKT) cells in NMOSD to disease and normal-healthy controls. METHODS: Peripheral blood cell (PBMC) samples from 45 patients with NMOSD with aquaporin 4 (AQP4)-IgG, 18 disease controls, and 19 normal controls were analyzed for CD16 expression and complement receptors in vitro. RESULTS: At baseline, the number of NKT cells was increased in NMOSD (p < 0.001), but the proportion that was CD16 positive was lower compared to normal and disease controls (p = 0.0012). NK cell count was normal, but the ratio that was CD16 positive was also significantly lower (p < 0.001). In both NK cells and NKT cells from NMOSD, C5 complement receptor expression was much higher than normal and disease controls (p < 0.001 for both). We also evaluated activation markers CD69 and CD83, which were also significantly higher in NK and NKT cells from NMOSD patients. FCGR3A p158 V/V genotype group in NMOSD patients showed decreased NK cell proportion with activation, and fewer CD16-expressing NKT cells than the F/F genotype group. DISCUSSION: Our results support an immunopathogenesis model in which complement pathway activation in NK/NKT cells upregulates CD16 expression that binds to antibody/antigen complexes. In the context of NMOSD, these complement-sensitive cells may be responsible for the escalating autoimmune activity.

COVID-19 and the risk of CNS demyelinating diseases: A systematic review.

Background: Viral infections are a proposed possible cause of inflammatory central nervous system (CNS) demyelinating diseases, including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). During the past 2 years, CNS demyelinating events associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been reported, but causality is unclear. Objective: To investigate the relationship between CNS demyelinating disease development and exacerbation with antecedent and/or concurrent SARS-CoV-2 infection. Methods: A systematic literature review of all publications describing either a new diagnosis or relapse of CNS demyelinating diseases (MS, NMOSD, MOGAD) in association with SARS-CoV-2 infection was performed utilizing PRISMA guidelines. Descriptive statistics were used for data analysis, using a case analysis approach. Results: Sixty-seven articles met the inclusion criteria for the study. Most of the reported cases of NMOSD (n = 13, 72.2% of reported cases) and MOGAD (n = 27, 96.5% of reported cases) were of new disease onset, presenting with typical clinical and radiographic features of these conditions, respectively. In contrast, reported MS cases varied amongst newly diagnosed cases (n = 10, 10.5% of reported cases), relapses (n = 63, 66.4%) and pseudo-relapses (n = 22, 23.2%). The median duration between COVID-19 infection and demyelinating event onset was 11.5 days (range 0-90 days) in NMOSD, 6 days (range-7 to +45 days) in MOGAD, and 13.5 days (range-21 to +180 days) in MS. Most cases received high-dose corticosteroids with a good clinical outcome. Conclusion: Based upon available literature, the rate of CNS demyelinating events occurring in the setting of preceding or concurrent SARS-CoV-2 infection is relatively low considering the prevalence of SARS-CoV-2 infection. The clinical outcomes of new onset or relapsing MS, NMOSD, or MOGAD associated with antecedent or concurrent infection were mostly favorable. Larger prospective epidemiological studies are needed to better delineate the impact of COVID-19 on CNS demyelinating diseases.

Follow-up of retinal thickness and optic MRI after optic neuritis in anti-MOG antibody-associated disease and anti-AQP4 antibody-positive NMOSD.

BACKGROUND: Retinal atrophy in the chronic phase of optic neuritis (ON) in anti-aquaporin-4 antibody (AQP4-Ab)-positive neuromyelitis optica spectrum disorder (NMOSD) and anti-myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) remains unclear. METHODS: Patients with these diseases were repeatedly evaluated using optical coherence tomography (OCT) for the circumpapillary retinal nerve fiber layer (cpRNFL) and macular ganglion cell complex (mGCC) in the ON-involved eyes during relapse-free period after the first ON episode before relapse. Optic MRI with short tau inversion recovery (STIR) sequences was further evaluated retrospectively. RESULTS: Twelve patients with MOGAD (20 eyes with ON-involvement) and 14 with AQP4-Ab-positive NMOSD (16 eyes with ON-involvement) were enrolled. The progression of retinal atrophy ≥12 months after onset was observed in AQP4-Ab-positive NMOSD, but was not apparent in MOGAD. A decrease in retinal thickness by the same amount results in more severe visual impairment in AQP4-Ab-positive NMOSD. On optic MRI, the residual STIR hyperintensity in the optic nerves remained in the chronic phase in almost all eyes with ON in both diseases. Optic nerve atrophy occurred in all evaluated ON-involved eyes in AQP4-Ab-positive NMOSD, while it was observed in half of ON-involved eyes in MOGAD. CONCLUSIONS: Progression of retinal atrophy in the chronic phase has been observed in patients with AQP4-Ab-positive NMOSD, while it remains uncertain in patients with MOGAD. The visual impairments upon similar levels of retinal atrophy would be worse in AQP4-Ab-positive NMOSD, possibly attributable in part to a higher incidence of optic nerve atrophy in this disease.

Hypertrophic Pachymeningitis Development in Eosinophilic Granulomatosis with Polyangiitis at Relapse of Disease: A Case-Based Review.

Hypertrophic pachymeningitis (HP) presents with thickening of the dura mater in the cerebrum and spine, and its symptoms vary depending on the affected location. The association of HP with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis has been recognized, and most cases are complicated by granulomatosis with polyangiitis. We report the case of a 47-year-old man who presented with HP upon relapse of eosinophilic granulomatosis with polyangiitis (EGPA), with literature review. He presented with disturbance of consciousness, and magnetic resonance imaging (MRI) revealed thickening of the dura mater around the left parietal lobe. Although myeloperoxidase (MPO)-ANCA was positive on EGPA diagnosis, the elevation of MPO-ANCA was not documented at the onset of HP. Brain perfusion scintigraphy showed an increase in blood flow in the left parietal lobe and temporal lobe, and electroencephalogram (EEG) revealed slow waves in the left parietal lobe. He was treated with a high dose of corticosteroid and rituximab, and the slow waves on EEG and brain perfusion were normalized. Although the most frequent symptom of HP is headache, disturbance of consciousness can be the manifestation of HP, and inflammation of HP could affect the cerebral parenchyma, which can be documented as abnormal EEG and perfusion scintigraphy. Literature review revealed that most of the HP in EGPA developed when EGPA relapsed, and was observed in patients with MPO-ANCA positivity. HP develops without evidence of other clinical features of EGPA; therefore, adequate imaging, including contrast-enhanced MRI, is necessary. Rituximab may be effective for treating HP complicated with EGPA.

A point-of-care diagnostic test for aquaporin-4 antibody seropositive neuromyelitis optica.

BACKGROUND: Given the need for specialized laboratory techniques, diagnostic testing for serum antibodies to aquaporin-4, a protein associated with neuromyelitis optica spectrum disorder (NMOSD), is not globally accessible. We aimed to evaluate a novel point-of-care, filter paper-based test for serum AQP4 antibodies (AQP4-Ab). METHODS: Adults with AQP4-Ab seropositive NMOSD and seronegative controls (with other central nervous system demyelinating diagnoses) used lancets to place blood drops (∼1 mL) on filter paper cards. Samples were analyzed after an average of 9.4 days using transfected AQP4-GFP HEK293 cells, and results were compared to participants' prior serum AQP4-Ab test results by blinded laboratory staff. RESULTS: Of 40 participants (mean age 53.7 years; 83% female), 25 were cases and 15 were controls. The most common diagnosis of controls was multiple sclerosis (73%). The average NMOSD disease duration was 6.3 years. All AQP4-Ab seropositive participants were on disease modifying therapies at the time of participation. The point-of-care test yielded a sensitivity of 80% and specificity of 93% (positive and negative predictive values 95% and 74%). CONCLUSION: This point-of-care AQP4-Ab testing method may become a pragmatic option to diagnose AQP4-Ab seropositive NMOSD in difficult-to-reach settings. This method should be confirmed with other testing parameters and field tested in new populations.

[Studying Abroad for Basic Research During the COVID-19 Pandemic].

The COVID-19 pandemic, caused by a new type of coronavirus, has increased the difficulty of studying abroad for basic research. However, the associated system has changed in response to the coronavirus disaster. In addition, a framework has been built to enable research to be conducted even under a new lifestyle. Although there are many differences betwee studying abroad currently and before the pandemic, you should not give up on your dreams; I encourage you to open the door and challenge yourself.

Relapse activity in the chronic phase of anti-myelin-oligodendrocyte glycoprotein antibody-associated disease.

OBJECTIVE: The patterns of relapse and relapse-prevention strategies for anti-myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are not completely investigated. We compared the patterns of relapse in later stages of MOGAD with those of anti-aquaporin-4 antibody (AQP4-Ab)-positive neuromyelitis optica spectrum disorder (NMOSD). METHODS: In this observational, comparative cohort study, 66 patients with MOGAD and 90 with AQP4-Ab-positive NMOSD were enrolled. We compared the patterns of relapse and annualized relapse rates (ARRs) in the first 10 years from disease onset, stratified by relapse-prevention treatments. RESULTS: Approximately 50% of the patients with MOGAD experienced relapses in the first 10 years. Among those not undergoing relapse-prevention treatments, ARRs in the first 5 years were slightly lower in MOGAD patients than in AQP4-Ab-positive NMOSD patients (MOGAD vs. AQP4-Ab NMOSD: 0.19 vs. 0.30; p = 0.0753). After 5 years, the ARR decreased in MOGAD patients (MOGAD vs. AQP4-Ab NMOSD: 0.05 vs. 0.34; p = 0.0001), with a 72% reduction from the first 5 years (p = 0.0090). Eight (61.5%) of the 13 MOGAD patients with more than 10-year follow-up from disease onset showed relapse 10 years after onset. Clustering in the timing and phenotype of attacks was observed in both disease patients. The effectiveness of long-term low-dose oral PSL for relapse prevention in patients with MOGAD has not been determined. CONCLUSIONS: The relapse risk in patients with MOGAD is generally lower than that in patients with AQP4-Ab-positive NMOSD, especially 5 years after onset. Meanwhile, relapses later than 10 years from onset are not rare in both diseases.

White blood cell count profiles in multiple sclerosis during attacks before the initiation of acute and chronic treatments.

Multiple sclerosis (MS) is a major demyelinating disease of the central nervous system; however, its exact mechanism is unknown. This study aimed to elucidate the profile of white blood cells (WBCs) in the acute phase of an MS attack. Sixty-four patients with MS at the time of diagnosis and 2492 age- and sex-adjusted healthy controls (HCs) were enrolled. Data regarding the blood cell counts were compared between the groups. The total WBC (p < 0.0001), monocyte (p < 0.0001), basophil (p = 0.0027), and neutrophil (p < 0.0001) counts were higher in the MS group than in the HC group, whereas the lymphocyte and eosinophil counts did not differ. Adjustments for the smoking status and body mass index yielded the same results. The total and differential WBC counts of the patients with MS did not correlate with the counts of T2 hyperintense brain lesions or the levels of neurological disturbance. In summary, patients with MS showed elevated counts of total WBCs, monocytes, basophils, and neutrophils at the time of diagnosis. However, the clinical relevance of these biomarkers in the context of the development and progression of MS remains unclear.

Five-year visual outcomes after optic neuritis in anti-MOG antibody-associated disease.

INTRODUCTION: Optic neuritis (ON) is a major phenotype of clinical attack related to demyelinating neurological diseases of the central nervous system, including multiple sclerosis (MS), anti-aquaporin-4 (AQP4) antibody-positive neuromyelitis optica spectrum disorder (NMOSD), and anti-myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). As the concept of MOGAD is relatively new, the long-term visual outcomes after ON in MOGAD remains unclear. METHODS: To elucidate the long-term visual prognosis after ON in MOGAD, patients with MOGAD whose visual acuity were regularly followed for more than 5 years from the onset of ON were enrolled. Best-corrected visual acuity (BCVA) at nadir in the acute phase and at 1 and 5 years from onset was evaluated. The data from patients with MOGAD were compared with those from patients with MS or anti-AQP4-positive NMOSD. RESULTS: Twenty-three patients (31 ON-involved eyes) with MOGAD, 20 patients (24 ON-involved eyes) with MS, and 22 patients (24 ON-involved eyes) with anti-AQP4-positive NMOSD were evaluated. All BCVA at nadir, 1 year, and 5 years from the onset of ON were much worse in anti-AQP4-positive NMOSD than in MS (p = 0.0024) and MOGAD (p = 0.0014) patients. In MOGAD and anti-AQP4-positive NMOSD, the serum disease-specific antibody titer was not associated with the subsequent visual prognosis. Visual acuity had almost fully recovered spontaneously or shortly after initiating acute treatment in 22 of the 23 patients with MOGAD-ON. The administration of high-dose intravenous steroid therapy further facilitated early recovery of visual acuity. Meanwhile, a small fraction of patients with extensive optic nerve lesions involving the chiasma irreversibly experienced severe visual impairment despite appropriate acute treatment. CONCLUSION: Although a small fraction of patients with MOGAD who presented with extensive optic nerve lesions experienced irreversible severe visual impairment, the long-term visual outcomes after 5 years from ON in patients with MOGAD were generally as good as that in patients with MS and much better than that in patients with anti-AQP4-positive NMOSD.

Difference in the Source of Anti-AQP4-IgG and Anti-MOG-IgG Antibodies in CSF in Patients With Neuromyelitis Optica Spectrum Disorder.

OBJECTIVE: To elucidate the differences in the source and in the level of intrathecal synthesis between anti-aquaporin-4 antibodies (AQP4-IgG) and anti-myelin oligodendrocyte glycoprotein antibodies (MOG-IgG). METHODS: Thirty-eight patients with MOG-IgG-associated disease and 36 with AQP4-IgG-positive neuromyelitis optica spectrum disorders (NMOSD) were studied for the antibody titers in the sera and CSF simultaneously collected in the acute attacks. The quotients between CSF and serum levels of albumin, total immunoglobulin G, and each disease-specific antibody were calculated. Intrathecal production level in each disease-specific antibody was evaluated by calculating the antibody index from these quotients. RESULTS: Eleven of the 38 patients with MOG-IgG were positive for the antibody only in the CSF, while no patient with AQP4-IgG showed CSF-restricted AQP4-IgG. Blood-brain barrier compromise as shown by raised albumin quotients was seen in 75.0% of MOG-IgG-positive cases and 43.8% of AQP4-IgG-positive cases. Moreover, MOG-IgG quotients were >10 times higher than AQP4-IgG quotients (effect size r = 0.659, p < 0.0001). Elevated antibody index (>4.0) was confirmed in 12 of 21 with MOG-IgG, whereas it was seen only in 1 of 16 with AQP4-IgG (φ = 0.528, p < 0.0001). The CSF MOG-IgG titers (ρ = 0.519, p = 0.001) and antibody indexes for MOG-IgG (ρ = 0.472, p = 0.036) correlated with the CSF cell counts but not with clinical disability. CONCLUSIONS: Intrathecal production of MOG-IgG may occur more frequently than that of AQP4-IgG. This finding implies the different properties of B-cell trafficking and antibody production between MOG-IgG-associated disease and AQP4-IgG-positive NMOSD.

Early Treatment Initiation With Oral Prednisolone for Relapse Prevention Alleviates Depression and Fatigue in Aquaporin-4-Positive Neuromyelitis optica Spectrum Disorder.

Background: Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing autoimmune-related neurological disorder of the central nervous system. Most patients with NMOSD have serum anti-aquaporin-4 immunoglobulin G antibodies (AQP4-IgG). In addition to optic neuritis and myelitis, other insidious symptoms such as depressive state and chronic fatigue in NMOSD are gradually being recognized. Methods: To elucidate the impact of low- to medium-dose oral prednisolone (PSL) as a relapse prevention therapy for psychiatric disturbances and chronic fatigue in NMOSD, we evaluated clinical data from 39 patients with AQP4-IgG-positive NMOSD, along with the details of present and cumulative oral PSL dosage. Results: Thirty-six of the 39 patients were treated with low- to medium-dose oral PSL, and the mean and standard deviation of the present daily dose of oral PSL were 7.9 ± 4.0 mg/day. None of the patients were treated with a daily PSL dose of >15 mg. As a result, the disease duration and the untreated period before starting oral PSL showed weak to moderate correlations with the subsequent severities of psychiatric disturbance and fatigue level. Meanwhile, none of the other treatment-related variables evaluated, such as the present oral PSL daily dose, cumulative PSL dose, months of oral PSL administration, previous courses of steroid pulse therapy, and coadministered immunosuppressants, were correlated with these insidious symptoms. Conclusion: Our results suggest that the use of long-term low- to medium-dose oral PSL ≤15 mg daily for relapse prevention in AQP4-IgG-positive NMOSD would not aggravate the psychiatric and fatigue conditions. On the contrary, early initiation of oral PSL for relapse prevention, together with significantly decreased relapse rate, alleviated the subsequent depressive state and fatigue from the disease.

Staging of astrocytopathy and complement activation in neuromyelitis optica spectrum disorders.

Aquaporin 4 (AQP4)-IgG-positive neuromyelitis optica spectrum disorder (AQP4-IgG+NMOSD) is an autoimmune astrocytopathic disease pathologically characterized by the massive destruction and regeneration of astrocytes with diverse types of tissue injury with or without complement deposition. However, it is unknown whether this diversity is derived from differences in pathological processes or temporal changes. Furthermore, unlike for the demyelinating lesions in multiple sclerosis, there has been no staging of astrocytopathy in AQP4-IgG+NMOSD based on astrocyte morphology. Therefore, we classified astrocytopathy of the disease by comparing the characteristic features, such as AQP4 loss, inflammatory cell infiltration, complement deposition and demyelination activity, with the clinical phase. We performed histopathological analyses in eight autopsied cases of AQP4-IgG+NMOSD. Cases comprised six females and two males, with a median age of 56.5 years (range, 46-71 years) and a median disease duration of 62.5 months (range, 0.6-252 months). Astrocytopathy in AQP4-IgG+NMOSD was classified into the following four stages defined by the astrocyte morphology and immunoreactivity for GFAP: (i) astrocyte lysis: extensive loss of astrocytes with fragmented and/or dust-like particles; (ii) progenitor recruitment: loss of astrocytes except small nucleated cells with GFAP-positive fibre-forming foot processes; (iii) protoplasmic gliosis: presence of star-shaped astrocytes with abundant GFAP-reactive cytoplasm; and (iv) fibrous gliosis: lesions composed of densely packed mature astrocytes. The astrocyte lysis and progenitor recruitment stages dominated in clinically acute cases (within 2 months after the last recurrence). Findings common to both stages were the loss of AQP4, a decreased number of oligodendrocytes, the selective loss of myelin-associated glycoprotein and active demyelination with phagocytic macrophages. The infiltration of polymorphonuclear cells and T cells (CD4-dominant) and the deposition of activated complement (C9neo), which reflects the membrane attack complex, a hallmark of acute NMOSD lesions, were selectively observed in the astrocyte lysis stage (98.4% in astrocyte lysis, 1.6% in progenitor recruitment, and 0% in protoplasmic gliosis and fibrous gliosis). Although most of the protoplasmic gliosis and fibrous gliosis lesions were accompanied by inactive demyelinated lesions with a low amount of inflammatory cell infiltration, the deposition of complement degradation product (C3d) was observed in all four stages, even in fibrous gliosis lesions, suggesting the past or chronic occurrence of complement activation, which is a useful finding to distinguish chronic lesions in NMOSD from those in multiple sclerosis. Our staging of astrocytopathy is expected to be useful for understanding the unique temporal pathology of AQP4-IgG+NMOSD.