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The pathological hallmark of multiple system atrophy (MSA) is aberrant accumulation of phosphorylated α-synuclein in oligodendrocytes, forming glial cytoplasmic inclusions (GCIs). Extensive demyelination occurs particularly in the olivopontocerebellar and striatonigral pathways, but its precise mechanism remains elusive. Glial connexins (Cxs), which form gap junction channels between astrocytes and oligodendrocytes, play critical roles in myelin maintenance, and have not been studied in MSA. Therefore, we immunohistochemically investigated glial Cx changes in the cerebellar afferent fibers in 15 autopsied patients with MSA. We classified demyelinating lesions into three stages based on Klüver-Barrera staining: early (Stage I), intermediate (Stage II), and late (Stage III) stages showing subtle, moderate, and severe myelin reduction, respectively. Myelin-associated glycoprotein, but not myelin oligodendrocyte glycoprotein, was preferentially decreased in Stage I, suggesting distal oligodendrogliopathy type demyelination. Accumulation of phosphorylated α-synuclein in oligodendrocytes was frequently seen in Stage I but less frequently observed in Stages II and III. Tubulin polymerization-promoting protein (TPPP/p25α)-positive oligodendrocytes were preserved in Stage I but successively decreased in Stages II and III. Even at Stage I, Cx32 was nearly absent from myelin, despite the relative preservation of other nodal proteins, such as neurofascin, claudin-11/oligodendrocyte-specific protein, and contactin-associated protein 1, which successively decreased in the later stages. Cx32 was re-distributed in the oligodendrocyte cytoplasm and co-localized with GCIs. Cx47 gradually decreased at the oligodendrocyte surface in a stage-dependent manner but was not co-localized with GCIs. Astrocytic Cx43 was down-regulated in Stage I but up-regulated in Stages II and III, reflecting astrogliosis. Cx43/Cx47 gap junctions significantly decreased from Stage I to III. Activated microglia/macrophages and T cells infiltrated in Stage I rather than Stages II and III. Therefore, early and extensive alterations of glial Cxs, particularly Cx32 loss, occur in MSA and may accelerate distal oligodendrogliopathy type demyelination and nodal/paranodal dysfunction through disruption of inter-glial communication.

ObjectiveTo evaluate whether eculizumab helps patients with anti–acetylcholine receptor–positive (AChR+) refractory generalized myasthenia gravis (gMG) achieve the Myasthenia Gravis Foundation of America (MGFA) post-intervention status of minimal manifestations (MM), we assessed patients' status throughout REGAIN (Safety and Efficacy of Eculizumab in AChR+ Refractory Generalized Myasthenia Gravis) and its open-label extension.MethodsPatients who completed the REGAIN randomized controlled trial and continued into the open-label extension were included in this tertiary endpoint analysis. Patients were assessed for the MGFA post-intervention status of improved, unchanged, worse, MM, and pharmacologic remission at defined time points during REGAIN and through week 130 of the open-label study.ResultsA total of 117 patients completed REGAIN and continued into the open-label study (eculizumab/eculizumab: 56; placebo/eculizumab: 61). At week 26 of REGAIN, more eculizumab-treated patients than placebo-treated patients achieved a status of improved (60.7% vs 41.7%) or MM (25.0% vs 13.3%; common OR: 2.3; 95% CI: 1.1–4.5). After 130 weeks of eculizumab treatment, 88.0% of patients achieved improved status and 57.3% of patients achieved MM status. The safety profile of eculizumab was consistent with its known profile and no new safety signals were detected.ConclusionEculizumab led to rapid and sustained achievement of MM in patients with AChR+ refractory gMG. These findings support the use of eculizumab in this previously difficult-to-treat patient population.ClinicalTrials.gov IdentifierREGAIN, NCT01997229; REGAIN open-label extension, NCT02301624.Classification of EvidenceThis study provides Class II evidence that, after 26 weeks of eculizumab treatment, 25.0% of adults with AChR+ refractory gMG achieved MM, compared with 13.3% who received placebo.

Background and ObjectivesThe choroid plexus has been shown to play a crucial role in CNS inflammation. Previous studies found larger choroid plexus in multiple sclerosis (MS) compared with healthy controls. However, it is not clear whether the choroid plexus is similarly involved in MS and in neuromyelitis optica spectrum disorder (NMOSD). Thus, the aim of this study was to compare the choroid plexus volume in MS and NMOSD.MethodsIn this retrospective, cross-sectional study, patients were included by convenience sampling from 4 international MS centers. The choroid plexus of the lateral ventricles was segmented fully automatically on T1-weighted MRI sequences using a deep learning algorithm (Multi-Dimensional Gated Recurrent Units). Uni- and multivariable linear models were applied to investigate associations between the choroid plexus volume, clinically meaningful disease characteristics, and MRI parameters.ResultsWe studied 180 patients with MS and 98 patients with NMOSD. In total, 94 healthy individuals and 47 patients with migraine served as controls. The choroid plexus volume was larger in MS (median 1,690 µL, interquartile range [IQR] 648 µL) than in NMOSD (median 1,403 µL, IQR 510 µL), healthy individuals (median 1,533 µL, IQR 570 µL), and patients with migraine (median 1,404 µL, IQR 524 µL; all p < 0.001), whereas there was no difference between NMOSD, migraine, and healthy controls. This was also true when adjusted for age, sex, and the intracranial volume. In contrast to NMOSD, the choroid plexus volume in MS was associated with the number of T2-weighted lesions in a linear model adjusted for age, sex, total intracranial volume, disease duration, relapses in the year before MRI, disease course, Expanded Disability Status Scale score, disease-modifying treatment, and treatment duration (beta 4.4; 95% CI 0.78–8.1; p = 0.018).DiscussionThis study supports an involvement of the choroid plexus in MS in contrast to NMOSD and provides clues to better understand the respective pathogenesis.

TMEM119 and purinergic receptor P2Y12 (P2RY12), which are not expressed by recruited peripheral blood macrophages, are proposed to discriminate microglia from macrophages. Therefore, we investigated the distribution patterns of microglia and macrophages in 10 concentric lesions from four autopsied Baló's disease cases and one neuromyelitis optica spectrum disorder (NMOSD) case, using quantitative immunohistochemistry for the markers TMEM119, P2RY12, CD68, CD163 and GLUT5. Three cases with Baló's disease had distal oligodendrogliopathy (DO) showing preferential loss of myelin-associated glycoprotein and early active demyelination in the outermost demyelinating layer (termed DMY-MO). In DMY-MO with DO, TMEM119-positive activated microglia expressing upregulated GLUT5 but markedly downregulated P2RY12 were significantly increased. These activated microglia expressed inducible nitric oxide synthase. Oligodendrocytes and their precursors showed apoptotic-like nuclear condensation in DMY-MO. TMEM119-negative and CD68/CD163-positive macrophages were distributed throughout the lesion center of DMY-MO with DO and these cells demonstrated foamy morphology only in the inner portion but not in the outer portion. In concentric demyelinating lesions from another Baló's case and lamellar demyelinating lesions in an NMOSD case, which had late active demyelination without DO, the densities of TMEM119-, GLUT5- and P2RY12-positive microglia with ramified morphology were significantly increased in myelinated layers but not in demyelinating layers. In particular, in the NMOSD case, TMEM119-positive microglia were confined to the outer portion of the myelinated layers. CD68-positive macrophages with foamy morphology also expressing CD163 accumulated in myelinated as well as in demyelinated layers. These findings suggest that activated microglia expressing TMEM119 and GLUT5, but not P2RY12, are associated with apoptosis of oligodendrocytes in the leading edge of Baló's concentric lesions with DO, whereas TMEM119-, GLUT5- and P2RY12-positive microglia with ramified morphology are associated with myelin preservation in concentric lesions without DO in Baló's disease and NMOSD. These two types of microglia appear to play distinct roles in the formation of concentric lesions.

Connexin 30 (Cx30), which forms gap junctions between astrocytes, regulates cell adhesion and migration, and modulates glutamate transport. Cx30 is upregulated on activated astroglia in central nervous system inflammatory lesions, including spinal cord lesions in mutant superoxide dismutase 1 (mSOD1) transgenic amyotrophic lateral sclerosis (ALS) model mice. Here, we investigated the role of Cx30 in mSOD1 mice. Cx30 was highly expressed in the pre-onset stage in mSOD1 mice. mSOD1 mice with knockout (KO) of the Cx30 gene (Cx30KO-mSOD1 mice) showed delayed disease onset and tended to have an extended survival period (log-rank, p = 0.09). At the progressive and end stages of the disease, anterior horn cells were significantly preserved in Cx30KO-mSOD1 mice. In lesions of these mice, glial fibrillary acidic protein/C3-positive inflammatory astroglia were decreased. Additionally, the activation of astrocytes in Cx30KO-mSOD1 mice was reduced compared with mSOD1 mice by gene expression microarray. Furthermore, expression of connexin 43 at the pre-onset stage was downregulated in Cx30KO-mSOD1 mice. These findings suggest that reduced expression of astroglial Cx30 at the early disease stage in ALS model mice protects neurons by attenuating astroglial inflammation.

HLA genotype-clinical phenotype correlations are not established for multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD). We studied HLA-DRB1/DPB1 genotype–phenotype correlations in 528 MS and 165 NMOSD cases using Japan MS/NMOSD Biobank materials. HLA-DRB1*04:05, DRB1*15:01 and DPB1*03:01 correlated with MS susceptibility and DRB1*01:01, DRB1*09:01, DRB1*13:02 and DPB1*04:01 were protective against MS. HLA-DRB1*15:01 was associated with increased optic neuritis and cerebellar involvement and worsened visual and pyramidal functional scale (FS) scores, resulting in higher progression index values. HLA-DRB1*04:05 was associated with younger onset age, high visual FS scores, and a high tendency to develop optic neuritis. HLA-DPB1*03:01 increased brainstem and cerebellar FS scores. By contrast, HLA-DRB1*01:01 decreased spinal cord involvement and sensory FS scores, HLA-DRB1*09:01 decreased annualized relapse rate, brainstem involvement and bowel and bladder FS scores, and HLA-DRB1*13:02 decreased spinal cord and brainstem involvement. In NMOSD, HLA-DRB1*08:02 and DPB1*05:01 were associated with susceptibility and DRB1*09:01 was protective. Multivariable analysis revealed old onset age, long disease duration, and many relapses as independent disability risks in both MS and NMOSD, and HLA-DRB1*15:01 as an independent risk only in MS. Therefore, both susceptibility and protective alleles can influence the clinical manifestations in MS, while such genotype–phenotype correlations are unclear in NMOSD.

To identify biomarkers for multiple system atrophy-cerebellar type (MSA-C), we used flow cytometry to measure surface marker expression of peripheral blood monocytes from patients with MSA-C or hereditary spinocerebellar degeneration (hSCD) and from healthy controls (HCs). The percentage of intermediate monocytes was significantly lower in MSA-C patients than in hSCD patients and HCs and showed significant positive correlations with disease duration and unified MSA rating scale scores. The percentage of CD62L+ intermediate monocytes was significantly lower in MSA-C patients than in hSCD patients and HCs. Early decrease of peripheral blood intermediate monocytes is characteristic of MSA-C and is a biomarker.

Objective To identify genetic factors associated with susceptibility to and clinical features of neuromyelitis optica spectrum disorders (NMOSD). Methods Genome-wide single nucleotide polymorphism (SNP) genotyping was conducted in 211 Japanese patients with NMOSD fulfilling the 2006 criteria with or without anti-aquaporin-4 (AQP4) antibody and 1,919 Japanese healthy controls (HCs). HLA-DRB1 and HLA-DPB1 alleles were genotyped in 184 NMOSD cases and 317 HCs. Multiple sclerosis (MS) risk alleles outside the major histocompatibility complex (MHC) region were tested in NMOSD and MS genetic burden (MSGB) scores were compared between HCs and NMOSD. Results A SNP (rs1964995) in the MHC region was associated with NMOSD susceptibility (odds ratio (OR) = 2.33, P = 4.07 × 10-11 ). HLA-DRB1*08:02 (OR = 2.86, P = 3.03 × 10-4 ) and HLA-DRB1*16:02 (OR = 8.39, P = 1.92 × 10-3 ) were risk alleles for NMOSD susceptibility whereas HLA-DRB1*09:01 was protective (OR = 0.27, P = 1.06 × 10-5 ). Three MS risk variants were associated with susceptibility and MSGB scores were significantly higher in NMOSD than in HCs (P = 0.0095). A SNP in the KCNMA1 (potassium calcium-activated channel subfamily M alpha 1) gene was associated with disability score with genome-wide significance (rs1516512, P = 2.33 × 10-8 ) and transverse myelitis (OR = 1.77, P = 0.011). KCNMA1 was immunohistochemically detected in the perivascular endfeet of astrocytes and its immunoreactivity was markedly diminished in active spinal cord lesions in NMOSD. Interpretation Specific HLA-DRB1 alleles confer NMOSD susceptibility and KCNMA1 is associated with disability and transverse myelitis in NMOSD.

Cortical lesions (CLs) have a low prevalence and are associated with physical disabilities in Japanese patients with multiple sclerosis (MS). However, the contribution of CLs to cognitive impairment remains unclear in Asian MS. Sixty-one prospectively enrolled MS patients underwent three-dimensional double inversion recovery MR imaging, the Brief Repeatable Battery of Neuropsychological Tests (BRB-N), the Apathy Scale (AS), the Fatigue Questionnaire (FQ), and the Hospital Anxiety and Depression Scale (HADS) within a 1-week period. The cognitive impairment index (CII) score was calculated to measure patients’ overall cognitive impairment. MS patients with CLs had poorer scores than those without CLs in most BRB-N tests, but scored comparably in the FQ, AS, and HADS. The number of CLs correlated negatively with all BRB-N test scores and positively with total CII scores. Leukocortical lesions were more extensively associated with cognitive dysfunction in various domains than intracortical lesions. Stepwise multiple regression analysis revealed that potential confounding factors for the highest quartile of CII score were the number of CLs (odds ratio 2.38, p = 0.0070) and the Expanded Disability Severity Scale score (odds ratio 2.13, p = 0.0003). Our results demonstrate that the presence and number of CLs are robustly associated with cognitive dysfunction in Asian MS patients.

ObjectiveNuclear depletion and mislocalization of RNA-binding proteins (RBPs) trans-activation response DNA-binding protein of 43 kDa (TDP-43) and fused in sarcoma (FUS) are thought to contribute to the pathogenesis of a number of disorders, including amyotrophic lateral sclerosis (ALS). We recently found that TDP-43 as well as polypyrimidine tract binding protein (PTB) have decreased expression and mislocalization in oligodendrocytes in demyelinated lesions in an experimental mouse model of multiple sclerosis (MS) caused by Theiler’s murine encephalomyelitis virus infection.MethodsThe latter finding prompted us to investigate TDP-43, FUS, and PTB in the demyelinated lesions of MS and inin vitro culturedhuman brain-derived oligodendrocytes.ResultsWe found: i) mislocalized TDP-43 in oligodendrocytes in active lesions in some MS patients; ii) decreased PTB1 expression in oligodendrocytes in mixed active/inactive demyelinating lesions; iii) decreased nuclear expression of PTB2 in neurons in cortical demyelinating lesions; iv) nuclear depletion of TDP-43 in oligodendrocytes under metabolic stress induced by low glucose/low nutrient conditions compared to optimal culture conditions.ConclusionTDP-43 has been found to have a key role in oligodendrocyte function and viability, while PTB is important in neuronal differentiation, suggesting that altered expression and mislocalization of these RBPs in MS lesions may contribute to the pathogenesis of demyelination and neurodegeneration. Our findings also identify nucleocytoplasmic transport as a target for treatment.

Background Complement is likely to have a role in refractory generalised myasthenia gravis, but no approved therapies specifically target this system. Results from a phase 2 study suggested that eculizumab, a terminal complement inhibitor, produced clinically meaningful improvements in patients with anti-acetylcholine receptor antibody-positive refractory generalised myasthenia gravis. We further assessed the efficacy and safety of eculizumab in this patient population in a phase 3 trial. Methods We did a phase 3, randomised, double-blind, placebo-controlled, multicentre study (REGAIN) in 76 hospitals and specialised clinics in 17 countries across North America, Latin America, Europe, and Asia. Eligible patients were aged at least 18 years, with a Myasthenia Gravis-Activities of Daily Living (MG-ADL) score of 6 or more, Myasthenia Gravis Foundation of America (MGFA) class II-IV disease, vaccination against Neisseria meningitides, and previous treatment with at least two immunosuppressive therapies or one immunosuppressive therapy and chronic intravenous immunoglobulin or plasma exchange for 12 months without symptom control. Patients with a history of thymoma or thymic neoplasms, thymectomy within 12 months before screening, or use of intravenous immunoglobulin or plasma exchange within 4 weeks before randomisation, or rituximab within 6 months before screening, were excluded. We randomly assigned participants (1:1) to either intravenous eculizumab or intravenous matched placebo for 26 weeks. Dosing for eculizumab was 900 mg on day 1 and at weeks 1, 2, and 3; 1200 mg at week 4; and 1200 mg given every second week thereafter as maintenance dosing. Randomisation was done centrally with an interactive voice or web-response system with patients stratified to one of four groups based on MGFA disease classification. Where possible, patients were maintained on existing myasthenia gravis therapies and rescue medication was allowed at the study physician's discretion. Patients, investigators, staff, and outcome assessors were masked to treatment assignment. The primary efficacy endpoint was the change from baseline to week 26 in MG-ADL total score measured by worst-rank ANCOVA. The efficacy population set was defined as all patients randomly assigned to treatment groups who received at least one dose of study drug, had a valid baseline MG-ADL assessment, and at least one post-baseline MG-ADL assessment. The safety analyses included all randomly assigned patients who received eculizumab or placebo. This trial is registered with ClinicalTrials.gov, number NCT01997229. Findings Between April 30, 2014, and Feb 19, 2016, we randomly assigned and treated 125 patients, 62 with eculizumab and 63 with placebo. The primary analysis showed no significant difference between eculizumab and placebo (least-squares mean rank 56·6 [SEM 4·5] vs 68·3 [4·5]; rank-based treatment difference -11·7, 95% CI -24·3 to 0·96; p=0·0698). No deaths or cases of meningococcal infection occurred during the study. The most common adverse events in both groups were headache and upper respiratory tract infection (ten [16%] for both events in the eculizumab group and 12 [19%] for both in the placebo group). Myasthenia gravis exacerbations were reported by six (10%) patients in the eculizumab group and 15 (24%) in the placebo group. Six (10%) patients in the eculizumab group and 12 (19%) in the placebo group required rescue therapy. Interpretation The change in the MG-ADL score was not statistically significant between eculizumab and placebo, as measured by the worst-rank analysis. Eculizumab was well tolerated. The use of a worst-rank analytical approach proved to be an important limitation of this study since the secondary and sensitivity analyses results were inconsistent with the primary endpoint result; further research into the role of complement is needed. Funding Alexion Pharmaceuticals.

Allergic and atopic disorders have increased over the past few decades and have been associated with neuropsychiatric conditions, such as autism spectrum disorder and asthmatic amyotrophy. Myelitis presenting with neuropathic pain can occur in patients with atopic disorder; however, the relationship between allergic inflammation and neuropathic pain, and the underlying mechanism, remains to be established. We studied whether allergic inflammation affects the spinal nociceptive system. We found that mice with asthma, atopic dermatitis, or atopic diathesis had widespread and significantly more activated microglia and astroglia in the spinal cord than those without atopy, and displayed tactile allodynia. Microarray analysis of isolated microglia revealed a dysregulated phenotype showing upregulation of M1 macrophage markers and downregulation of M2 markers in atopic mice. Among the cell surface protein genes, endothelin receptor type B (EDNRB) was most upregulated. Immunohistochemical analysis revealed that EDNRB expression was enhanced in microglia and astroglia, whereas endothelin-1, an EDNRB ligand, was increased in serum, lungs, and epidermis of atopic mice. No EDNRA expression was found in the spinal cord. Expression of FBJ murine osteosarcoma viral oncogene homolog B was significantly higher in the dorsal horn neurons of asthma mice than nonatopic mice. The EDNRB antagonist BQ788 abolished glial and neural activation and allodynia. We found increased serum endothelin-1 in atopic patients with myelitis and neuropathic pain, and activation of spinal microglia and astroglia with EDNRB upregulation in an autopsied case. These results suggest that allergic inflammation induces diffuse glial activation, influencing the nociceptive system via the EDNRB pathway.SIGNIFICANCE STATEMENTThe prevalence of allergic disorders has markedly increased over the past few decades. Allergic disorders are associated with neuropsychiatric conditions; however, the relationship between allergic inflammation and CNS complications is unknown. A peculiar myelitis presenting with persistent neuropathic pain has been reported in patients with allergic disorders. We studied how atopy exerts substantial influence on the nociceptive system. We found that mice with allergic disorders had severe allodynia with activated astroglia and microglia, and showed marked upregulation of endothelin-1 (ET-1) receptor type B (EDNRB) in the spinal cord. A selective EDNRB antagonist prevented allodynia and glial activation. Our findings suggest a novel mechanism whereby atopy induces glial activation and neuropathic pain via an ET-1/EDNRB pathway.

Background We previously reported that Vδ2+Vγ9+ γδ T cells were significantly decreased in multiple sclerosis (MS) patients without disease-modifying therapies (untreated MS) and were negatively correlated with Expanded Disability Status Scale (EDSS) scores, suggesting protective roles of Vδ2+Vγ9+ γδ T cells. Interferon-β (IFN-β) is one of the first-line disease-modifying drugs for MS. However, no previous studies have reported changes in γδ T cell subsets under IFN-β treatment. Therefore, we aimed to clarify the effects of the long-term usage of IFN-β on γδ T cell subsets in MS patients. Methods Comprehensive flow cytometric immunophenotyping was performed in 35 untreated MS and 21 MS patients on IFN-β for more than 2 years (IFN-β-treated MS) including eight super-responders fulfilling no evidence of disease activity criteria, and 44 healthy controls (HCs). Results The percentages of Vδ2+Vγ9+ cells in γδ T cells were significantly lower in untreated and IFN-β-treated MS patients than in HCs. By contrast, the percentages of Vδ1−Vδ2−Vγ9− cells in γδ T cells were markedly higher in IFN-β-treated MS patients than in HCs and untreated MS patients (both p < 0.001). A significant negative correlation between the percentages of Vδ2+Vγ9+ cells in γδ T cells and EDSS scores was confirmed in untreated MS but not evident in IFN-β-treated MS. Moreover, class-switched memory B cells were decreased in IFN-β-treated MS compared with HCs (p < 0.001) and untreated MS patients (p = 0.006). Interestingly, the percentages of Vδ1−Vδ2−Vγ9− cells in γδ T cells were negatively correlated with class-switched memory B cell percentages in all MS patients (r = − 0.369, p = 0.005), and the percentages of Vδ1−Vδ2−Vγ9− cells in Vδ1−Vδ2− γδ T cells were negatively correlated with EDSS scores only in IFN-β super-responders (r = − 0.976, p < 0.001). Conclusions The present study suggests that long-term usage of IFN-β increases Vδ1−Vδ2−Vγ9− γδ T cells, which are associated with a better outcome, especially in IFN-β super-responders. Thus, increased Vδ1−Vδ2−Vγ9− cells together with decreased class-switched memory B cells may contribute to the suppression of disease activity in MS patients under IFN-β treatment.

Neuromyelitis optica, a rare neuroinflammatory demyelinating disease of the CNS, is characterized by the presence of specific pathogenic autoantibodies directed against the astrocytic water channel aquaporin 4 (AQP4) and is now considered as an astrocytopathy associated either with complement-dependent astrocyte death or with astrocyte dysfunction. However, the link between astrocyte dysfunction and demyelination remains unclear. We propose glial intercellular communication, supported by connexin hemichannels and gap junctions, to be involved in demyelination process in neuromyelitis optica. Using mature myelinated cultures, we demonstrate that a treatment of 1 h to 48 h with immunoglobulins purified from patients with neuromyelitis optica (NMO-IgG) is responsible for a complement independent demyelination, compared to healthy donors’ immunoglobulins (P

Connexin36 (Cx36) forms gap junctions between neurons, which are called electrical synapses, enabling adjacent neurons to communicate directly. The participation of chemical synapses in neurodegeneration in amyotrophic lateral sclerosis (ALS) has long been indicated, but it remains unclear whether electrical synapses are involved in the pathogenesis of ALS. We performed extensive immunopathological analyses using mutant superoxide dismutase 1 (SOD1G93A) transgenic mice and their littermates to investigate whether Cx36-made electrical synapses are affected in motor neuron diseases. We found that in the lamina IX of the lumbar spinal cord from wild type mice, about half of the Cx36 puncta existed independently of chemical synapse markers, while the rest coexisted with chemical synapse markers, such as vesicular glutamate transporter 1 (VGLUT1), which is a glutamatergic axon terminal marker, and/or glutamate decarboxylase 65 (GAD65), which is a GABAergic axon terminal marker. Cx36 single or Cx36/GAD65 double positive puncta, but not VGLUT1-containing puncta, were preferentially decreased on neuronal and dendritic surfaces of the anterior horn cells in the early stage of SOD1G93A ALS mice. Moreover, in five human autopsied sporadic ALS cases with bulbar or upper limb onset, Cx36 immunoreactivity was diminished in the proximal dendrites and neuropils of well-preserved large motor neurons in the lumbar anterior horns. These findings suggest that downregulation of neuronal and dendritic Cx36 in the spinal anterior horns commonly occurs from the early stage of hereditary and sporadic ALS. Cx36-made electrical synapses without glutamatergic signaling appear to be more vulnerable than other chemical synapses and electrical synapses with glutamatergic signaling in the early stage of motor neuron degeneration, suggesting involvement of Cx36-made electrical synapses in the pathogenesis of human ALS.

Hypertrophic pachymeningitis (HP) is a rare neurologic disease causing inflammatory fibrous thickening of the brain and spinal dura mater. We investigated the cerebrospinal fluid cytokine profile of HP by measuring 28 cytokines/chemokines/growth factors with a multiplexed fluorescent immunoassay in 8 patients with HP (6 idiopathic, 1 IgG4-related, 1 anti-neutrophil cytoplasmic antibody-related), and 11 with other non-inflammatory neurologic diseases (OND). Interleukin (IL)-4, IL-5, IL-9, IL-10, TNF-α, and CXCL8/IL-8 levels were significantly higher in idiopathic HP (IHP) than OND. Cluster analyses disclosed two major clusters: one mainly consisted of IHP and the other of OND, suggesting a unique cytokine profile in IHP.

Objectives Studies of longitudinally extensive spinal cord lesions (LESCLs) in neuromyelitis optica (NMO) have focused on gray matter, where the relevant antigen, aquaporin-4 (AQP4), is abundant. Because spinal white matter pathology in NMO is not well characterized, we aimed to clarify spinal white matter pathology of LESCLs in NMO. Methods We analyzed 50 spinal cord lesions from eleven autopsied NMO/NMO spectrum disorder (NMOSD) cases. We also evaluated LESCLs with three or fewer spinal cord attacks by 3-tesla MRI in 15 AQP4 antibody-positive NMO/NMOSD patients and in 15 AQP4 antibody-negative multiple sclerosis (MS) patients. Results Pathological analysis revealed seven cases of AQP4 loss and four predominantly demyelinating cases. Forty-four lesions from AQP4 loss cases involved significantly more frequently posterior columns (PC) and lateral columns (LC) than anterior columns (AC) (59.1%, 63.6%, and 34.1%, respectively). The posterior horn (PH), central portion (CP), and anterior horn (AH) were similarly affected (38.6%, 36.4% and 31.8%, respectively). Isolated perivascular inflammatory lesions with selective loss of astrocyte endfoot proteins, AQP4 and connexin 43, were present only in white matter and were more frequent in PC and LC than in AC (22.7%, 29.5% and 2.3%, Pcorr = 0.020, and Pcorr = 0.004, respectively). MRI indicated LESCLs more frequently affected PC and LC than AC in anti-AQP4 antibody-seropositive NMO/NMOSD (86.7%, 60.0% and 20.0%, Pcorr = 0.005, and Pcorr = 0.043, respectively) and AQP4 antibody-seronegative MS patients (86.7%, 73.3% and 33.3%, Pcorr = 0.063, and Pcorr = 0.043, respectively). PH, CP and AH were involved in 93.3%, 86.7% and 73.3% of seropositive patients, respectively, and in 53.3%, 60.0% and 40.0% of seronegative patients, respectively. Conclusions NMO frequently and extensively affects spinal white matter in addition to central gray matter, especially in PC and LC, where isolated perivascular lesions with astrocyte endfoot protein loss may emerge. Spinal white matter involvement may also appear in early NMO, similar to cerebral white matter lesions.

ObjectiveTo determine whether there are nuclear depletion and cellular mislocalization of RNA-binding proteins (RBPs) transactivation response DNA-binding protein of 43 kDa (TDP-43), fused in sarcoma (FUS), and polypyrimidine tract–binding protein (PTB) in MS, as is the case in amyotrophic lateral sclerosis (ALS) and oligodendrocytes infected with Theiler murine encephalomyelitis virus (TMEV), we examined MS lesions and in vitro cultured primary human brain–derived oligodendrocytes.MethodsNuclear depletion and mislocalization of TDP-43, FUS, and PTB are thought to contribute to the pathogenesis of ALS and TMEV demyelination. The latter findings prompted us to investigate these RBPs in the demyelinated lesions of MS and in in vitro cultured human brain–derived oligodendrocytes under metabolic stress conditions.ResultsWe found (1) mislocalized TDP-43 in oligodendrocytes in active lesions in some patients with MS; (2) decreased PTB1 expression in oligodendrocytes in mixed active/inactive demyelinating lesions; (3) decreased nuclear expression of PTB2 in neurons in cortical demyelinating lesions; and (4) nuclear depletion of TDP-43 in oligodendrocytes under metabolic stress induced by low glucose/low nutrient conditions compared with optimal culture conditions.ConclusionTDP-43 has been found to have a key role in oligodendrocyte function and viability, whereas PTB is important in neuronal differentiation, suggesting that altered expression and mislocalization of these RBPs in MS lesions may contribute to the pathogenesis of demyelination and neurodegeneration. Our findings also identify nucleocytoplasmic transport as a target for treatment.

We recently reported that deletion-type copy number variations of the T cell receptor (TCR) gamma, alfa, and delta genes greatly enhanced susceptibility to multiple sclerosis (MS). However, the effect of abnormal TCR gamma delta gene rearrangement on MS pathogenesis remains unknown. In the present study, we aimed to clarify gamma delta TCR repertoire alterations and their relationship to clinical and immunological parameters in MS patients by comprehensive flow cytometric immunophenotyping. Peripheral blood mononuclear cells obtained from 30 untreated MS patients in remission and 23 age- and sex-matched healthy controls (HCs) were stained for surface markers and intracellular cytokines after stimulation with phorbol 12-myristate 13-acetate and ionomycin, and analyzed by flow cytometry. MS patients showed significantly decreased percentages of Vdelta2+ and Vdelta2+Vgamma9+ cells in gamma delta T cells (pcorr = 0.0297, and pcorr = 0.0288, respectively) and elevated Vdelta1/Vdelta2 ratios compared with HCs (p = 0.0033). The percentages of interferon (IFN)-gamma+Vdelta2+ and interleukin (IL)-17A+IFN-gamma+Vdelta2+ cells in gamma delta T cells, as well as IFN-gamma+ cells in Vdelta2+ gamma delta T cells, were significantly lower in MS patients than in HCs (pcorr < 0.0009, pcorr = 0.0135, and pcorr = 0.0054, respectively). The percentages of Vdelta2+ and Vdelta2+Vgamma9+ cells in gamma delta T cells were negatively correlated with both the Expanded Disability Status Scale score (r = −0.5006, p = 0.0048; and r = −0.5040, p = 0.0045, respectively) and Multiple Sclerosis Severity Score (r = –0.4682, p = 0.0091; and r = –0.4706, p = 0.0087, respectively), but not with age at disease onset, disease duration, or annualized relapse rate. In HCs, the percentages of Vdelta2+ and Vdelta2+Vgamma9+ cells of total CD3+ T cells had strong positive correlations with the percentage of CD25+CD127low/− cells in CD4+ T cells (r = 0.7826, p < 0.0001; and r = 0.7848, p < 0.0001, respectively), whereas such correlations were totally absent in MS patients. These findings suggest that decreased Vdelta2+Vgamma9+ gamma delta T cells are associated with disability in MS. Therefore, the Vdelta1/Vdelta2 ratio might be a candidate biomarker for predicting disease severity in MS.

ObjectiveRecent studies based on the neuroimaging analysis, genomic analysis and transcriptome analysis of the postmortem brain suggest that the pathogenesis of schizophrenia is related to myelin-oligodendrocyte abnormalities. However, no serious neuropathological investigation of this protein in the schizophrenic brain has yet been performed. In this study, to confirm the change in neuropathological findings due to the pathogenesis of this disease, we observed the expression of myelin-oligodendrocyte directly in the brain tissue of schizophrenia patients.MethodsMyelin oligodendrocyte glycoprotein (MOG) was evaluated in the cortex of the superior temporal gyrus (STG) and the hippocampus in 10 schizophrenic and nine age- and sex-matched normal control postmortem brains.ResultsThe expression of MOG was significantly lower in the middle layer of the neocortex of the STG and stratum lucidum of CA3 in the hippocampus in the long-term schizophrenic brains (patients with ≥30 years of illness duration) than in the age-matched controls. Furthermore, the thickness of MOG-positive fibre-like structures was significantly lower in both regions of the long-term schizophrenic brains than in the age-matched controls.ConclusionThese findings suggest that a long duration of illness has a marked effect on the expression of MOG in these regions, and that myelin-oligodendrocyte abnormalities in these regions may be related to the progressive pathophysiology of schizophrenia.

Objective To clarify the potential association of copy number variations (CNVs) with multiple sclerosis (MS) and neuromyelitis optica (NMO) in Japanese cases. Methods Genome-wide association analyses of CNVs among 277 MS patients, 135 NMO/NMO spectrum disorder (NMOSD) patients, and 288 healthy individuals as a discovery cohort, and among 296 MS patients, 76 NMO/NMOSD patients, and 790 healthy individuals as a replication cohort were performed using high-density single nucleotide polymorphism microarrays. Results A series of discovery and replication studies revealed that most identified CNVs were 5 to 50kb deletions at particular T cell receptor (TCR) gamma and alpha loci regions. Among these CNVs, a TCR gamma locus deletion was found in 16.40% of MS patients (p = 2.44E-40, odds ratio [OR] = 52.6), and deletion at the TCR alpha locus was found in 17.28% of MS patients (p = 1.70E-31, OR = 13.0) and 13.27% of NMO/NMOSD patients (p = 5.79E-20, OR = 54.6). These CNVs were observed in peripheral blood T-cell subsets only, suggesting the CNVs were somatically acquired. NMO/NMOSD patients carrying the CNV tended to be seronegative for anti–aquaporin-4 antibody or had significantly lower titers than those without CNV. Interpretation Deletion-type CNVs at specific TCR loci regions contribute to MS and NMO susceptibility. Ann Neurol 2015;78:Ann Neurol 2015;78:679–696

Multiple sclerosis (MS), neuromyelitis optica (NMO), and Balo's disease (BD) are inflammatory demyelinating diseases of the CNS. We previously reported anti-aquaporin-4 (anti-AQP4) antibody-dependent AQP4 loss occurs in some NMO patients, while antibody-independent AQP4 astrocytopathy can occur in heterogeneous demyelinating conditions, including MS, NMO and BD. To investigate the relationship between astrocytopathy and demyelination, we focused on connexins (Cxs), which form gap junctions (GJs) between astrocytes and oligodendrocytes and maintain homeostasis in the CNS. We evaluated expression of astrocytic Cx43/Cx30 and oligodendrocytic Cx47/Cx32 in autopsied materials from MS, NMO and BD patients. Astrocytic Cx43 and oligodendrocytic Cx32/Cx47 expressions were significantly diminished in both demyelinated and preserved myelin layers in all BD samples. In the leading edge of BD lesions, Cx43 and AQP4 loss preceded Cx32/Cx47 loss. Half of the NMO and MS samples showed preferential loss of astrocytic Cx43 expression in actively demyelinating and chronic active lesions, where heterotypic Cx43/Cx47 astrocyte-oligodendrocyte GJs were lost. Cases with Cx43 loss were significantly associated with rapid disease progression, regardless of the disease phenotype. Pathologically, Cx43 loss was frequently accompanied by distal oligodendrogliopathy. Our findings suggest that Cx43 astrocytopathy can occur in MS, BD and NMO. Moreover, astrocytic Cx43 loss may be associated with disease aggressiveness and distal oligodendrogliopathy in demyelinating conditions. Early disruption of glial communications via GJs may cause loss of glia syncytium, thereby inducing oligodendroglial damage and myelin loss. Inhibition of Cx hemichannels and restoration of GJs may be a possible therapeutic target for demyelinating disorders.

Data regarding vitamin D in multiple sclerosis (MS) in Asia are limited. We investigated whether Japanese MS patients show decreased serum 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)2D], and vitamin D-binding protein (DBP) during winter. Mean serum 25(OH)D and 1,25(OH)2D levels were significantly lower in MS patients than in controls. There were no significant differences in serum 25(OH)D, 1,25(OH)2D, and DBP levels between patients or between controls from northern Japan (Hokkaido) and southern Japan (Kyushu). Serum vitamin D levels were low in Japanese MS patients but did not differ in patients from northern and southern Japan.

Objective Neuromyelitis optica (NMO) is an inflammatory disease in which NMO-immunoglobulin G (IgG) targeting aquaporin-4 (AQP4) is specifically detected. Although the main subclass of AQP4 antibody was reported to be in the IgG1 subclass, other subclasses have also been described, including IgG2 AQP4 antibody, as a second common subclass. NMO patients were analyzed to clarify the clinical features of NMO patients with IgG2 AQP4 antibody. Methods Serum samples from 58 NMO patients, who met the revised 2006 criteria for NMO, were analyzed for AQP4 antibody subclass expression using an established flow cytometric assay, and clinical features were compared according to the main AQP4 antibody subclasses. Results A total of 50 patients (86.2%) had IgG1 AQP4 antibodies, while eight (13.8%) expressed IgG2 AQP4 antibody as the main subclass. Those eight individuals exhibited younger age of onset (P = 0.0089), lower AQP4 antibody titers (P = 0.0024) and a more common fulfillment of Barkhof's criteria (P = 0.0466) than patients with IgG1 AQP4 antibody expression. Conclusions Results from the present study suggest that the characteristics of individuals with IgG2 AQP4 antibody as a main subclass are more similar to multiple sclerosis and somewhat distinct from NMO patients with IgG1 AQP4 antibody.

Background: Cortical lesions (CLs) frequently observed in Caucasian patients with multiple sclerosis (MS) contribute to disability. However, it remains unclear whether CLs are associated with clinical features and genetic risk factors, such as HLA-DRB1*15:01 and -DRB1*04:05 in Asian MS patients. Objective: To elucidate the frequency of CLs and their association with HLA-DRB1 and DPB1 alleles in Japanese MS patients. Methods: Three-dimensional double inversion recovery imaging and clinical information were retrospectively obtained from 92 Japanese MS patients. Results: CLs of any type, intracortical lesions (ICLs), and leukocortical lesions (LCLs) were detected in 39.1%, 26.1%, and 28.3% of patients, respectively. MS patients with ICLs had a significantly higher frequency of secondary progression and greater Expanded Disability Status Scale (EDSS) scores than those without ICLs. Similar trends were observed with CLs and LCLs. The number of all three lesion types positively correlated with EDSS scores. The frequency and number of ICLs were significantly higher in HLA-DRB1*15:01 carriers than in HLA-DRB1*15:01 non-carriers, but significantly lower in HLA-DRB1*04:05 carriers than in HLA-DRB1*04:05 non-carriers. Multivariate logistic regression analysis revealed a negative association of HLA-DRB1*04:05 with ICLs. Conclusion: ICLs are associated with greater disease severity in Japanese MS patients and are partly suppressed by the HLA-DRB1*04:05 allele.

Objective Recent evidence has suggested the importance of an aberrantly activated monocyte system in amyotrophic lateral sclerosis (ALS) pathogenesis. However, the roles of each monocyte subset, namely CD14+CD16− classical monocytes, CD14dimCD16+ non-classical monocytes and CD14+CD16+ intermediate monocytes, in ALS remain unknown. We aimed to clarify the alterations in the monocyte subset proportions and the surface marker expressions on each monocyte subset in ALS. Methods Blood samples were collected from 19 ALS patients and 28 healthy controls (HC). The surface expressions of CCR2, CX3CR1, CD64 and CD62L were measured in the three monocyte subsets (classical, non-classical and intermediate) by flow cytometry. Results The percentages of CCR2 and CD62L on CD14+CD16− classical monocytes were significantly lower in ALS patients than in HC (P = 0.0012 and P = 0.0296, respectively). No differences were found in CX3CR1 and CD64 on each monocyte subset. The percentage of intermediate monocytes showed a significant negative correlation with the revised ALS functional rating scale score (r = −0.631, P = 0.0038). Conclusions Reductions in chemotaxis- and adhesion-related molecules on classical inflammatory monocytes are present in ALS, further suggesting the involvement of an aberrant innate immune system in ALS pathogenesis.

We previously reported early and extensive loss of astrocytic connexin 43 (Cx43) in acute demyelinating lesions of multiple sclerosis (MS) patients. Because it is widely accepted that autoimmune T cells initiate MS lesions, we hypothesized that infiltrating T cells affect Cx43 expression in astrocytes, which contributes to MS lesion formation. Primary mixed glial cell cultures were prepared from newborn mouse brains, and microglia were isolated by anti-CD11b antibody-conjugated magnetic beads. Next, we prepared astrocyte-rich cultures and astrocyte/microglia-mixed cultures. Treatment of primary mixed glial cell cultures with interferon (IFN) γ, interleukin (IL)-4, or IL-17 showed that only IFNγ or IL-17 at high concentrations reduced Cx43 protein levels. Upon treatment of astrocyte-rich cultures and astrocyte/microglia-mixed cultures with IFNγ, Cx43 mRNA/protein levels and the function of gap junctions were reduced only in astrocyte/microglia-mixed cultures. IFNγ-treated microglia-conditioned media and IL-1β, which was markedly increased in IFNγ-treated microglia-conditioned media, reduced Cx43 protein levels in astrocyte-rich cultures. Finally, we confirmed that Th1 cell-conditioned medium decreased Cx43 protein levels in mixed glial cell cultures. These findings suggest that Th1 cell-derived IFNγ activates microglia to release IL-1β that reduces Cx43 gap junctions in astrocytes. Thus, Th1-dominant inflammatory states disrupt astrocytic intercellular communication and may exacerbate MS.

Multiple sclerosis (MS), neuromyelitis optica (NMO) and Bal� o’s disease (BD) are inflammatory demyelinating diseases of the central nervous system (CNS). We previously reported aquaporin-4 (AQP4) loss without perivascular deposition of complement or immunoglobulin in demyelinating diseases, suggesting that astrocytic damage could be a common denominator in heterogeneous demyelinating conditions. To investigate the relationship between astrocytopathy and demyelination, we focused on connexins (Cxs), which form gap junction channels between astrocytes and oligodendrocytes, and maintain myelination and homeostasis in the CNS. We pathologically evaluated the expression of astrocytic Cx43/Cx30 and oligodendrocytic Cx47/Cx32 in autopsied tissue samples from MS, NMO and BD patients. In all BD samples, astrocytic Cx43 and oligodendrocytic Cx32/Cx47 expression was diminished in both demyelinated and preserved myelin layers. In the leading edge of BD lesions, Cx43 and AQP4 loss preceded Cx32/Cx47 loss. Half of the NMO and MS samples showed preferential loss of astrocytic Cx43 in actively demyelinating and chronic active lesions, where heterotypic Cx43/Cx47 astrocyte-oligodendrocyte gap junctions were lost. Cases with Cx43 loss were significantly associated with rapid disease progression (death within 2 years after onset), regardless of the disease phenotype. Pathologically, Cx43 loss was frequently accompanied by distal oligodendrogliopathy. These findings suggest that Cx43 astrocytopathy can occur in MS, BD and NMO. Furthermore, astrocytic Cx43 loss might be associated with disease aggressiveness and distal oligodendrogliopathy, not only in BD,but also MS and NMO. Early disruption of astrocytic foot processes could precede demyelination and contribute to the pathogenesis of demyelinating disorders.

Objectives To clarify the prevalence, frequent causes and distinct features of hypertrophic pachymeningitis (HP) according to background conditions in a nationwide survey in Japan. Methods The study began with a preliminary survey to determine the approximate number of HP patients diagnosed from 1 January 2005 to 31 December 2009, and was followed by a questionnaire survey for clinical and laboratory findings. HP was defined as a condition with thickening of the cranial or spinal dura mater with inflammation, evidenced by MRI or histology. Results Crude HP prevalence was 0.949/100 000 population. The mean age at onset was 58.3±15.8 years. Among 159 cases for whom detailed data were collated, antineutrophil cytoplasmic antibody (ANCA)-related HP was found in 54 cases (34.0%) and IgG4/multifocal fibrosclerosis (MFS)-related HP in 14 cases (8.8%). Seventy cases (44.0%) were classified as ‘idiopathic’ and 21 (13.2%) as ‘others’. ANCA-related HP cases showed a female preponderance, a higher age of onset, and higher frequencies of otological symptoms and elevated systemic inflammatory biomarkers, but lower frequencies of diplopia compared with idiopathic HP. IgG4/MFS-related HP cases showed a marked male predominance; all had cranial HP while none had isolated spinal HP or decreased sensation. Conclusions HP is not extremely rare. ANCA-related HP is the most frequent form, followed by IgG4/MFS-related HP. Both forms have unique features, which may help to differentiate background causes.

Objectives Human peripheral blood monocytes comprise three different subtypes: CD14+CD16− (classical type), CD14lowCD16+ (non-classical type) and CD14+CD16+ (intermediate type). These subsets are known to have different functions, but little is known about their roles in multiple sclerosis (MS), especially for maintaining remission. We aimed to clarify the alterations in monocyte subsets in patients with MS and neuromyelitis optica (NMO)/NMO spectrum disorder (NMOSD) in the remission phase. Methods Blood samples were collected from 19 MS patients and 10 NMO/NMOSD patients in the remission phase, and 42 healthy controls (HC). The surface expressions of CCR2, CX3CR1, CD64 (FcγR1) and CD62L were analyzed in the monocyte subsets by flow cytometry. Results CCR2 expression was significantly decreased in classical monocytes from MS patients, regardless of interferon-β (IFN-β) treatment, but not in those from NMO/NMOSD patients. CX3CR1 expression was also decreased in all monocyte subsets from MS patients receiving IFN-β, whereas CX3CR1 expression in classical monocytes was only decreased in NMO/NMOSD patients receiving prednisolone. In NMO/NMOSD patients on prednisolone, the percentages of CD14+CD16+ intermediate monocytes, CD14lowCD16+ non-classical monocytes and CD64+CD14+CD16+ monocytes among total monocytes were significantly lower than in HC. CD62L expression on the monocyte subsets showed no significant differences among the patients and HC. Conclusions Our findings suggest that alterations in chemokine receptor expressions on peripheral blood monocytes can occur in MS and NMO/NMOSD during the remission phase. Down-modulation of CCR2 in MS, and CX3CR1 in MS and NMO/NMOSD could partly contribute to sustained remission by preventing monocyte infiltration into the central nervous system.

Neuromyelitis optica (NMO) is an inflammatory disease that selectively affects the optic nerves and spinal cord. The discovery of NMO-IgG targeting aquaporin-4 (AQP4) in NMO patients suggested that NMO is a distinct entity, with a fundamentally different etiology from that of multiple sclerosis (MS). Although NMO usually leads to grave disability because of the more severe tissue destruction compared with classical MS, there have been several reports describing a benign form of NMO over a long disease term. NMO-IgG/AQP4 antibodies show high specificity but medium sensitivity for NMO, while the clinical relevance of AQP4 antibody titers remains to be determined. We aimed to clarify the clinical relevance of AQP4 antibody levels determined by a bridging enzyme-linked immunosorbent assay in 38 patients with NMO or NMO spectrum disorder. The AQP4 antibody levels were higher in patients with optic neuritis (ON) than in those without ON (p = 0.0164). Among the 12 patients examined in a longitudinal study, four showed an increase in the ELISA values during some relapses, and eight showed no clear correlation between the ELISA values and relapse. Of the four patients who demonstrated a steady rise in the antibody levels over time, two patients had no concomitant relapses, despite elevation of the AQP4 antibody levels. We conclude that high AQP4 antibody levels are associated with the occurrence of ON, but that the antibody levels themselves are not closely correlated with the onset of relapse.

We herein report an autopsy case of the Marburg variant of multiple sclerosis (MS). A 29-year-old woman developed acute and progressive neurological symptoms. A diagnosis of MS was suspected based on the patient's clinical background and brain MRI findings and the lack of evidence of malignancy on a brain biopsy. Despite the administration of typical treatment for MS, a fatal outcome occurred three months after disease onset. The autopsy revealed multiple inflammatory demyelinating lesions in the central nervous system. In addition, two noteworthy histopathological features were observed compared with prototypical MS. We evaluate the pathogenic differences between the Marburg type and prototypical MS by discussing the neuropathology and cerebrospinal fluid (CSF) findings of our case.

Objective To clarify whether genetic and common infectious backgrounds are distinct, according to anti-aquaporin 4 (AQP4) antibody status in Japanese patients with neuromyelitis optica (NMO). Methods We analysed human leucocyte antigen (HLA)-DRB1 and HLA-DPB1 alleles, and IgG antibodies against Helicobacter pylori , Chlamydia pneumoniae , varicella zoster virus and Epstein–Barr virus nuclear antigen (EBNA) in 116 patients with NMO, including 39 patients with neuromyelitis optica spectrum disorder (NMOSD), 145 multiple sclerosis (MS) patients and 367 unrelated healthy controls. 77 NMO/NMOSD patients were seropositive for AQP4 antibody while 39 were seronegative. Results Compared with healthy controls, NMO/NMOSD patients showed a significantly lower frequency of DRB1*0901 and significantly higher frequencies of DRB1*1602 and DPB1*0501 , which conferred susceptibility to anti-AQP4 antibody positive NMO/NMOSD, but not antibody negative NMO/NMOSD. DRB1*0901 was a common protective allele, irrespective of the presence or absence of anti-AQP4 antibody. Anti- H pylori and anti- C pneumoniae antibodies were more commonly detected in anti-AQP4 antibody positive NMO/NMOSD patients than healthy controls. Antibody negative NMO/NMOSD patients did not differ from healthy controls regarding the presence of these antibodies. The presence or absence of antibodies against varicella zoster virus and EBNA did not vary among the groups. The frequencies of antibodies against these four pathogens were not significantly different between MS patients and healthy controls. Conclusions Our results suggest that HLA-DRB1*1602 and DPB1*0501 alleles and H pylori and Chlamydia pneumonia infection are risk factors only for anti-AQP4 antibody positive NMO/NMOSD but not for anti-AQP4 antibody negative NMO/NMOSD.

To determine the relationship between susceptibility to atopic myelitis (AM) and polymorphisms of the human leukocyte antigen ( HLA )- DPB1 and - DRB1 alleles, we compared each phenotype frequency between 55 AM patients and 367 unrelated healthy controls in Japan. The HLA - DPB1 * 0201 allele was significantly more frequent in AM patients than in healthy controls (54.5% vs. 31.9%, corrected P value = 0.0150, odds ratio = 2.564, 95% confidence interval = 1.444–4.554). Our result suggests that the immunogenetic background of AM differs from that of other CNS autoimmune diseases, such as multiple sclerosis and neuromyelitis optica, which show distinct HLA class II associations.

Background and objective: The objective of this study is to clarify clinical, immunological, and neuroimaging features in anti-aquaporin-4 (AQP4) antibody-positive and antibody-negative Sjögren’s syndrome (SS) patients with central nervous system (CNS) involvement. Methods: Medical records and MRI scans were retrospectively analyzed in 22 consecutive SS patients with CNS manifestations. Results: Seven (31.8%) patients were positive for anti-AQP4 antibodies. The frequency of visual impairment was higher in anti-AQP4 antibody-positive patients than in antibody-negative patients (71.4% vs. 0.0%, p = 0.0008). Brain MRI showed that discrete lesions were more commonly found in the cerebrum, brainstem, and optic nerve in anti-AQP4 antibody-positive patients than in antibody-negative patients ( p = 0.002, p = 0.006, and p = 0.004, respectively), while spinal cord MRI showed that posterior column lesions in the cervical spinal cord were more frequent in anti-AQP4 antibody-positive patients than in antibody-negative patients (71.4% vs. 14.3%, p = 0.01). SS-A antibody titers were higher in anti-AQP4 antibody-positive patients than in antibody-negative patients ( p = 0.012) and were also higher in patients with longitudinally extensive spinal cord lesions (LESCLs) than in those without LESCLs ( p = 0.019). Conclusions: In SS, the presence of anti-AQP4 antibodies is associated with involvement of the optic nerve, cerebrum and brainstem, and with cervical posterior column lesions in the spinal cord.

We describe an autopsied case of an 86-year-old woman who presented with acute tetraparesis, bulbar palsy, and respiratory insufficiency. MRI showed a T2 hyperintensity lesion in the medulla oblongata and C1 and C2 level cervical cord, and an unruptured aneurysm in the left posterior inferior cerebellar artery. With an initial diagnosis of Bickerstaffs brainstem encephalitis, we started corticosteroid therapy. Initially, the corticosteroid treatment gradually improved her general condition; however, about two weeks later she died of an acute respiratory insufficiency. From the postmortem pathological examination, we considered a venous circulatory disturbance of the medulla oblongata and upper cervical cord. No arteriovenous shunt was found in the intramedulla and the medulla oblongata was partially compressed on the left side by an unruptured aneurysm. However, neither inflammatory nor malignant cells were found in the lesion. What caused the venous circulatory disturbance was unclear, but the dural arteriovenous fistula could have been responsible. Our case suggested that venous circulatory disturbances accompanied with an aneurysm need rapid consideration by angiography followed by intervention.