Expression and role of nicotinic acetylcholine receptors during midbrain dopaminergic neuron differentiation from human induced pluripotent stem cells.

AIM: Nicotinic acetylcholine receptors (nAChRs) expressed in midbrain dopaminergic (mDA) neurons modulate mDA neuronal activity. However, their expression patterns and functional roles during mDA neuronal development remain unknown. Here, we profiled the expression and function of nAChR subtypes during mDA neuron differentiation from human induced pluripotent stem cells (hiPSCs). METHODS: Midbrain dopaminergic neurons were differentiated from hiPSCs using a recently developed proprietary method that replicates midbrain development. The expression patterns of developmental marker proteins were monitored during mDA neuronal differentiation using immunohistochemical analysis. Gene expression of nAChR subtypes was analyzed by reverse transcription polymerase chain reaction. Pharmacological nAChR agonists and antagonists were used to reveal the role of the α6 nAChR subunit in the differentiation of mDA neurons from hiPSCs. RESULTS: CHRNA4 expression was detected at the mDA neural progenitor stage, whereas CHRNA6 expression began during the mDA neuronal stage. CHRNA7 was expressed throughout the differentiation process, including in the undifferentiated hiPSCs. We also found that LMO3, a gene expressed in a subset of substantia nigra pars compacta (SNC) DA neurons in the midbrain, showed increased expression following nicotine treatment in a concentration-dependent manner. Additionally, 5-iodo A85380, a selective α6 nAChR agonist, also increased LMO3 expression in hiPSC-derived mDA neurons, and this increase was suppressed by simultaneous treatment with bPiDi, a selective α6 nAChR antagonist. CONCLUSION: Our findings suggest that stimulating the α6 nAChR subunit on hiPSC-derived mDA neurons may induce neuronal maturation that is biased toward SNC DA neurons.

[Morvan syndrome associated with unresectable thymoma responsive to chemotherapy: a case report].

A 51-year-old Japanese man presenting with a several-month history of parasomnia, orthostatic hypotension and generalized myokymia was admitted to our hospital. He had a past medical history of unresectable recurrent thymoma, but chemotherapy for thymoma was discontinued according to the patient's decision four years before this hospitalization, and the thymoma had enlarged. He exhibited symptoms of the peripheral nervous system (myokymia), central nervous system (parasomnia, short-term memory impairment), and autonomic nervous system (orthostatic hypotension), and his serum was positive for voltage-gated potassium channel (VGKC)-complex antibodies. Based on the above findings, Morvan syndrome was diagnosed. Resumption of chemotherapy for thymoma resulted in shrinkage of the thymoma accompanied by remission of Morvan syndrome. Subsequently, discontinuation of chemotherapy led to aggravation of thymoma with recurrence of Morvan syndrome. This clinical course suggests a strong correlation between the disease activity of thymoma and Morvan syndrome. In the present case of Morvan syndrome associated with unresectable thymoma, chemotherapy contributed to the remission of Morvan syndrome. Our patient suggests a possibility that chemotherapy for thymoma is a useful treatment for Morvan syndrome.

[A case of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) complicated by chronic intestinal pseudo-obstruction].

A 42-year-old woman presented at our hospital with acute paraphasia and word finding difficulty. She was not paralyzed or ataxic. Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) was diagnosed based on brain MRI finding of edematous lesions in bilateral temporal lobe cortexes that did not match the vascular territory, elevated lactate and pyruvate levels in blood and cerebrospinal fluid, and the presence of a mtDNA 3243A>G mutation. From six months before her visit, she had persistent anorexia, bloating, nausea and vomiting, and weight loss to 25 kg. We diagnosed her condition as chronic intestinal pseudo-obstruction (CIPO) associated with MELAS, because a gastroenterologist had previously diagnosed her with megacolon associated with colonic dysfunction. Usually, CIPO is often associated with the chronic phase of MELAS. However, since CIPO complication from the early stage of the disease is occasionally encountered, it is necessary to include mitochondrial disease in differential diagnosis of CIPO of unknown cause.

Nicotinic Acetylcholine Receptors and Microglia as Therapeutic and Imaging Targets in Alzheimer's Disease.

Amyloid-ß (Aß) accumulation and tauopathy are considered the pathological hallmarks of Alzheimer's disease (AD), but attenuation in choline signaling, including decreased nicotinic acetylcholine receptors (nAChRs), is evident in the early phase of AD. Currently, there are no drugs that can suppress the progression of AD due to a limited understanding of AD pathophysiology. For this, diagnostic methods that can assess disease progression non-invasively before the onset of AD symptoms are essential, and it would be valuable to incorporate the concept of neurotheranostics, which simultaneously enables diagnosis and treatment. The neuroprotective pathways activated by nAChRs are attractive targets as these receptors may regulate microglial-mediated neuroinflammation. Microglia exhibit both pro- and anti-inflammatory functions that could be modulated to mitigate AD pathogenesis. Currently, single-cell analysis is identifying microglial subpopulations that may have specific functions in different stages of AD pathologies. Thus, the ability to image nAChRs and microglia in AD according to the stage of the disease in the living brain may lead to the development of new diagnostic and therapeutic methods. In this review, we summarize and discuss the recent findings on the nAChRs and microglia, as well as their methods for live imaging in the context of diagnosis, prophylaxis, and therapy for AD.

Efficacy and Safety of Ultrahigh-Dose Methylcobalamin in Early-Stage Amyotrophic Lateral Sclerosis: A Randomized Clinical Trial.

Importance: The effectiveness of currently approved drugs for amyotrophic lateral sclerosis (ALS) is restricted; there is a need to develop further treatments. Initial studies have shown ultrahigh-dose methylcobalamin to be a promising agent. Objective: To validate the efficacy and safety of ultrahigh-dose methylcobalamin for patients with ALS enrolled within 1 year of onset. Design, Setting, and Participants: This was a multicenter, placebo-controlled, double-blind, randomized phase 3 clinical trial with a 12-week observation and 16-week randomized period, conducted from October 17, 2017, to September 30, 2019. Patients were recruited from 25 neurology centers in Japan; those with ALS diagnosed within 1 year of onset by the updated Awaji criteria were initially enrolled. Of those, patients fulfilling the following criteria after 12-week observation were eligible for randomization: 1- or 2-point decrease in the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) total score, a percent forced vital capacity greater than 60%, no history of noninvasive respiratory support and tracheostomy, and being ambulatory. The target participant number was 64 in both the methylcobalamin and placebo groups. Patients were randomly assigned through an electronic web-response system to methylcobalamin or placebo. Interventions: Intramuscular injection of methylcobalamin (50-mg dose) or placebo twice weekly for 16 weeks. Main Outcomes and Measures: The primary end point was change in ALSFRS-R total score from baseline to week 16 in the full analysis set. Results: A total of 130 patients (mean [SD] age, 61.0 [11.7] years; 74 men [56.9%]) were randomly assigned to methylcobalamin or placebo (65 each). A total of 129 patients were eligible for the full analysis set, and 126 completed the double-blind stage. Of these, 124 patients proceeded to the open-label extended period. The least square means difference in ALSFRS-R total score at week 16 of the randomized period was 1.97 points greater with methylcobalamin than placebo (-2.66 vs -4.63; 95% CI, 0.44-3.50; P = .01). The incidence of adverse events was similar between the 2 groups. Conclusions and Relevance: Results of this randomized clinical trial showed that ultrahigh-dose methylcobalamin was efficacious in slowing functional decline in patients with early-stage ALS and with moderate progression rate and was safe to use during the 16-week treatment period. Trial Registration: ClinicalTrials.gov Identifier: NCT03548311.

Ubiquitin-dependent rapid degradation conceals a cell-protective function of cytoplasmic SIRT3 against oxidative stress.

SIRT3 is an NAD+-dependent protein deacetylase localized in mitochondria. Several studies reported localization of SIRT3 in the cytoplasm or nucleus, but data of these studies were not consistent. We detected expression of mitochondrial (SIRT3mt) and cytoplasmic (SIRT3ct) Sirt3 mRNAs in the mouse brain, and we also found SIRT3 immunostaining of mitochondria and cytoplasm in the brain and cultured neural cells. However, expression levels of SIRT3ct in COS cells transfected with SIRT3ct cDNA were much lower than those of SIRT3mt. We found that SIRT3ct but not SIRT3mt was promptly degraded by ubiquitin-dependent degradation, in which SIRT3ct degradation was mediated mainly by ubiquitination of NH2-terminal methionine and partly by that of lysine residues of SIRT3ct. SIRT3ct expression level was significantly enhanced by the treatment of cells with staurosporine or H2O2. H2O2 treatment promoted nuclear translocation of SIRT3ct and induced histone H3 deacetylation and superoxide dismutase 2 expression. Overexpression of SIRT3ct decreased cell death caused by H2O2 at levels similar to those achieved by overexpression of SIRT3mt. Knockdown of Sirt3 mRNA increased cell death caused by amyloid-ß (Aß), and overexpression of SIRT3ct suppressed the toxic function of Aß in PC12 cells. These results indicate that SIRT3ct promotes cell survival under physiological and pathological conditions.

[A case of neuronal intranuclear inclusion disease with serial MRI changes observed from before onset of forgetfulness].

A 70-year-old woman presented with a 6-year history of cognitive dysfunction, neurogenic bladder, constipation and recurrent vomiting, and gradual worsening of symptoms. At the first admission to our department, she was also found to have hepatic encephalopathy due to intrahepatic portosystemic shunt. Head MRI revealed abnormal signal intensity at the corticomedullary junction, the splenium of the corpus callosum, and bilateral middle cerebellar peduncles on DWI. She was diagnosed with intranuclear inclusion disease (NIID) based on skin biopsy and genetic testing of NOTCH2NLC. In a retrospective review of serial head MRI findings for ten years, abnormal signal intensity at the corticomedullary junction and the splenium of the corpus callosum on MRI existed prior to the onset of cognitive dysfunction, and expanded gradually. For early diagnosis of NIID, it is important to focus not only on the characteristic high signal intensity at the corticomedullary junction, but also on the signal at the splenium of the corpus callosum from the early stage.

Abrupt Onset of Cardiac Tamponade in Sarcoidosis.

Sarcoidosis is a systemic inflammatory disease characterized by the formation of noncaseating epithelioid granulomas. Multiple organs, including the lung, eyes, and skin, are involved in this disorder, and cardiac involvement is a major cause of morbidity and mortality in patients with this disorder. We present the case history of a 22-year-old man with neurosarcoidosis complicated by abrupt onset of cardiac tamponade. Cardiac tamponade is a rare but potentially fatal manifestation of sarcoidosis, which is treatable with glucocorticoid therapy. Including the present case, previously reported cases of sarcoidosis with cardiac tamponade are reviewed to delineate its clinical characteristics.

Roles of microglia in Alzheimer's disease and impact of new findings on microglial heterogeneity as a target for therapeutic intervention.

Microglia are specialized macrophages that reside within the central nervous system and play key roles in brain immunity, development and homeostasis. Recent studies also revealed functions of microglia in neuroprotection and neuroinflammation, leading to the discovery that microglia are involved in several brain pathologies including Alzheimer's disease (AD). However, the beneficial and detrimental actions of this intriguing cell population can be challenging to dissect: the advent of single-cell and single-nucleus transcriptomic technologies has revolutionized our understanding of the heterogeneity of multiple cell types and is now being applied to the study of microglia in health and disease. Here, we review recent findings on microglial biology, focusing on insights from single cell transcriptomic studies and the heterogeneity that they reveal, and consider the impact of these findings on our understanding of AD. We also discuss how microglia might represent a next-generation therapeutic target for treatment of AD and other neuroinflammatory conditions.

Generation of striatal neurons from human induced pluripotent stem cells by controlling extrinsic signals with small molecules.

Human induced pluripotent stem cells (hiPSCs) are powerful tools for modeling human brain development and treating neurodegenerative diseases. Here we established a robust protocol with high scalability for generating striatal medium spiny neurons (MSNs) from hiPSCs using small molecules under two- and three-dimensional culture conditions. Using this protocol, GSH2+ lateral ganglionic eminence (LGE) progenitors were generated in two-dimensional culture by Sonic hedgehog signaling activation using purmorphamine, WNT signaling inhibition using XAV939, and dual-SMAD inhibition using LDN193189 and A83-01. Quantitative PCR analysis revealed sequential expression of LGE and striatal genes during differentiation. These LGE progenitors subsequently gave rise to DARPP32+ MSNs exhibiting spontaneous and evoked monophasic spiking activity. Applying this protocol in three-dimensional culture, we generated striatal neurospheres with gene expression profiles and cell layer organization resembling that of the developing striatum, including distinct ventricular and subventricular zones and DARPP32+ neurons at the surface. This protocol provides a useful experimental model for studying striatal development and yields cells potentially applicable for regenerative medicine to treat striatum-related disorders such as Huntington's disease.

Early detection of redox imbalance in the APPswe/PS1dE9 mouse model of Alzheimer's disease by in vivo electron paramagnetic resonance imaging.

Alzheimer's disease (AD) is a common neurodegenerative disease that causes progressive cognitive decline. Deposition of amyloid-ß (Aß) peptides is the most important pathophysiological hallmark of AD. Oxidative stress induced by the generation of reactive oxygen species (ROS) is a prominent phenomenon in AD and is known to occur early in its course. Several reports have suggested a relationship between changes in redox status and AD pathology, including progressive Aß deposition, glial cell activation, and inflammation. In the present study, we employed a newly designed three-dimensional continuous-wave digital electron paramagnetic resonance (EPR) imager with a blood-brain barrier (BBB)-permeable redox-sensitive piperidine nitroxide probe, 4-oxo-2,2,6,6-tetramethyl-piperidine-d16-1-oxyl, for early detection of changed brain redox status. Using this system, we noninvasively compared age-matched 7-month-old AD model mice with normal littermates (WT mice). The obtained brain redox images of AD and WT mice clearly showed impaired brain redox status of AD mice compared to WT, suggesting that oxidative damage had already increased in 7-month-old AD mice compared with age-matched WT mice. The pathological changes in 7-month-old mice in this study were detected earlier than in previous studies in which only AD mice older than 9 months of age could be imaged. Since EPR images suggested that oxidative damage was already increased in 7-month-old AD mice compared to age-matched WT mice, we also evaluated antioxidant levels and the activity of superoxide dismutase (SOD) in brain tissue homogenates of 7-month-old AD and WT mice. Compared to WT mice, decreased levels of glutathione and mitochondrial SOD activity were found in AD mice, which supports the EPR imaging results indicating impaired brain redox status. These results indicate that the EPR imaging method developed in this study is useful for early noninvasive detection of altered brain redox status due to oxidative disease.

Clinicopathologic Features of Oculopharyngodistal Myopathy With LRP12 CGG Repeat Expansions Compared With Other Oculopharyngodistal Myopathy Subtypes.

Importance: Repeat expansion of CGG in LRP12 has been identified as the causative variation of oculopharyngodistal myopathy (OPDM). However, to our knowledge, the clinicopathologic features of OPDM with CGG repeat expansion in LRP12 (hereafter referred to as OPDM_LRP12) remain unknown. Objective: To identify and characterize the clinicopathologic features of patients with OPDM_LRP12. Design, Setting, and Participants: This case series included 208 patients with a clinical or clinicopathologic diagnosis of oculopharyngeal muscular dystrophy (OPDM) from January 1, 1978, to December 31, 2020. Patients with GCN repeat expansions in PABPN1 were excluded from the study. Repeat expansions of CGG in LRP12 were screened by repeat primed polymerase chain reaction and/or Southern blot. Main Outcomes and Measures: Clinical information, muscle imaging data obtained by either computed tomography or magnetic resonance imaging, and muscle pathologic characteristics. Results: Sixty-five Japanese patients with OPDM (40 men [62%]; mean [SD] age at onset, 41.0 [10.1] years) from 59 families with CGG repeat expansions in LRP12 were identified. This represents the most common OPDM subtype among all patients in Japan with genetically diagnosed OPDM. The expansions ranged from 85 to 289 repeats. A negative correlation was observed between the repeat size and the age at onset (r2 = 0.188, P = .001). The most common initial symptoms were ptosis and muscle weakness, present in 24 patients (37%). Limb muscle weakness was predominantly distal in 53 of 64 patients (83%), but 2 of 64 patients (3%) had predominantly proximal muscle weakness. Ptosis was observed in 62 of 64 patients (97%), and dysphagia or dysarthria was observed in 63 of 64 patients (98%). A total of 21 of 64 patients (33%) had asymmetric muscle weakness. Aspiration pneumonia was seen in 11 of 64 patients (17%), and 5 of 64 patients (8%) required mechanical ventilation. Seven of 64 patients (11%) developed cardiac abnormalities, and 5 of 64 patients (8%) developed neurologic abnormalities. Asymmetric muscle involvement was detected on computed tomography scans in 6 of 27 patients (22%) and on magnetic resonance imaging scans in 4 of 15 patients (27%), with the soleus and the medial head of the gastrocnemius being the worst affected. All 42 muscle biopsy samples showed rimmed vacuoles. Intranuclear tubulofilamentous inclusions were observed in only 1 of 5 patients. Conclusions and Relevance: This study suggests that OPDM_LRP12 is the most frequent OPDM subtype in Japan and is characterized by oculopharyngeal weakness, distal myopathy that especially affects the soleus and gastrocnemius muscles, and rimmed vacuoles in muscle biopsy.

[A case of Charcot-Marie-Tooth disease type 2Z caused by MORC2 S87L mutation mimicking spinal muscular atrophy].

A 33-year-old man with an unremarkable family history has had limb muscle weakness, joint contracture and skeleton deformation from early childhood. He was diagnosed with spinal muscular atrophy (SMA) by a pediatrician. He needed assistance and used orthoses in his daily life. There was no subjective sensory disturbance. However, physical examination showed slight sensory impairment, and nerve conduction study indicated sensory motor axonal neuropathy. This finding suggested Charcot-Marie-Tooth disease (CMT). Gene analysis detected MORC2 S87L mutation, leading to a diagnosis of CMT type 2Z. Patients with MORC2 S87L mutation are known to exhibit a severe phenotype, and may mimic SMA. It is important to demonstrate subclinical sensory neuropathy in patients with MORC2 S87L mutation mimicking SMA.

Sporadic Amyotrophic Lateral Sclerosis Due to a FUS P525L Mutation with Asymmetric Muscle Weakness and Anti-ganglioside Antibodies.

Amyotrophic lateral sclerosis (ALS) due to a fused in sarcoma (FUS) P525L mutation is characterized by a rapidly progressive course. Multifocal motor neuropathy (MMN) may resemble ALS in early stage and is associated with anti-ganglioside antibodies. A 38-year-old woman was admitted to our hospital because of progressive muscle weakness in the right limbs. She had mild mental retardation and minor deformities. Initially, we suspected MMN given the asymmetric muscle weakness and detection of anti-ganglioside antibodies. However, physical and electrophysiological tests did not support MMN, instead suggesting ALS. We confirmed a heterozygous P525L mutation and finally diagnosed this case as ALS due to an FUS mutation.

SIRT1 decelerates morphological processing of oligodendrocyte cell lines and regulates the expression of cytoskeleton-related oligodendrocyte proteins.

SIRT1 is involved in the regulation of a variety of biological processes such as metabolism, stress response, autophagy and differentiation. Although progenitor cells of oligodendrocytes (OPCs) express high level of SIRT1, its function on differentiation is unknown. Because we have shown that SIRT1 plays a pivotal role in differentiation of neural precursor cells, we hypothesized that SIRT1 may also participate in the differentiation of oligodendrocytes (OLGs). We examined whether SIRT1 was expressed in two human oligodendrocyte cell lines: KG-1-C and MO 3.13 OLG. Transfection of cell lines with SIRT1-siRNA and SIRT2-siRNA promoted the extension of cellular processes. SIRT1-siRNA and SIRT2-siRNA increased acetyl-α-tubulin level, conversely, over expression of SIRTs resulted in decreased the ratio of acetyl-α-tubulin to α-tubulin. We also found knockdown of SIRT1 and SIRT2 induced overexpression of ßIV-tubulin and tubulin polymerization promoting protein (TPPP) (OLG-specific cytoskeleton-related molecules) that distributed widely in cell bodies. Taken together, SIRT1 may play a role in oligodenroglial differentiation and myelinogenesis.

Multiple system atrophy in Hokkaido, Japan: a prospective registry study of natural history and symptom assessment scales followed for 5 years.

OBJECTIVES: Multiple system atrophy (MSA) is a refractory neurodegenerative disease, but novel treatments are anticipated. An accurate natural history of MSA is important for clinical trials, but is insufficient. This regional registry was launched to complement clinical information on MSA. SETTING: Patient recruitment started in November 2014 and is ongoing at the time of submission. The number of participating facilities was 66. Postal surveys were sent to medical facilities and patients with MSA in Hokkaido, Japan. PARTICIPANTS: After obtaining written consent from 196 participants, 184 overview surveys and 115 detailed surveys were conducted. PRIMARY AND SECONDARY OUTCOME MEASURES: An overview survey evaluated conformity to diagnostic criteria and a detailed survey implemented an annual assessment based on the Unified Multiple System Atrophy Rating Scale (UMSARS). RESULTS: At the time of registration, 58.2% of patients were diagnosed with cerebellar symptoms predominant type MSA (MSA-C) and 29.9% were diagnosed with parkinsonism predominant type MSA (MSA-P). UMSARS Part Ⅳ score of 4 or 5 accounted for 53.8% of participants. The higher the UMSARS Part Ⅳ score, the higher the proportion of MSA-P. At baseline, levodopa was used by 69 patients (37.5%) and the average levodopa dose was 406.7 mg/day. The frequency of levodopa use increased over time. Eleven cases changed from MSA-C to MSA-P during the study, but the opposite was not observed. Information about survival and causes of death was collected on 54 cases. Half of deaths were respiratory-related. Sudden death was recorded even in the group with UMSARS Part Ⅳ score of 1. CONCLUSIONS: This study is the first large-scale prospective MSA cohort study in Asia. MSA-C was dominant, but the use of antiparkinsonian drugs increased over the study period. Changes from MSA-C to MSA-P occurred, but not vice versa.

[A case of facial-onset sensory and motor neuronopathy (FOSMN) with cerebellar ataxia and abnormal decrement in repetitive nerve stimulation test].

A 59-year-old woman presented with a 7-year history of facial numbness on the left side, and gradual worsening of symptoms. Over several years, facial muscle weakness, dysarthria, tongue atrophy and fasciculation had progressed. Then, she developed cerebellar ataxia affecting the left extremities, in addition to earlier symptoms. Brain MRI revealed cerebellar atrophy, and 99mTc-SPECT depicted cerebellar hypoperfusion. A repetitive nerve stimulation test (RNS) indicated abnormal decrement in the nasalis and trapezius muscles on the left side. Facial-onset sensory and motor neuronopathy (FOSMN) was diagnosed. Administration of intravenous immunoglobulin resulted in improvement of some symptoms. Although cerebellar ataxia is not a common symptom of FOSMN, a case showing TDP-43-positive glial cytoplasmic inclusions in cerebellar white matter has been reported. Therefore, it is possible that FOSMN may cause cerebellum impairment in some patients. Furthermore, RNS positive rate in the trapezius muscle is known to be high in amyotrophic lateral sclerosis (ALS) patients. It is speculated that RNS of the affected muscles in FOSMN may show abnormal decrement by the same mechanisms as ALS.

HLA genotype-clinical phenotype correlations in multiple sclerosis and neuromyelitis optica spectrum disorders based on Japan MS/NMOSD Biobank data.

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.