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The pathophysiology of unilateral cortical fluid-attenuated inversion recovery (FLAIR)-hyperintense lesions in anti-myelin oligodendrocyte glycoprotein (MOG)-associated encephalitis with seizures (FLAMES) is unclear. A 26-year-old man was referred because of a seizure. FLAIR showed an increased signal intensity and swelling of the right frontal cortex. His symptoms and imaging abnormalities were improved after intravenous methylprednisolone therapy. MOG antibody was detected both in serum and cerebrospinal fluid (CSF). Therefore, the patient was diagnosed with FLAMES. Myelin basic protein (MBP) was elevated in CSF. The high MBP value in the CSF in the present case suggested that demyelination as well as inflammation can occur in some FLAMES patients.

Autonomic disorders are common in patients with systemic lupus erythematosus (SLE), but the therapeutic strategy and methods for evaluating the effects of therapy have not been established. We describe the three cases of SLE patients who developed severe autonomic disorders as demonstrated by the head-up tilt table test (HUT). All three patients were treated by intensive immunosuppressive treatments including intravenous cyclophosphamide (IVCY); their HUT results all became negative. Our cases suggest that IVCY treatment can be a good therapeutic option for severe autonomic disorders in SLE patients. The HUT is a useful objective method for the diagnosis of and the evaluation of longitudinal therapeutic effects on autonomic disorders in SLE patients with orthostatic intolerance., Modern Rheumatology Case Reports, 6 (1), pp. 47-51; 2022

BackgroundAutoimmune autonomic ganglionopathy (AAG) is a rare disorder characterized by autonomic failure associated with the presence of anti-ganglionic acetylcholine receptor (gAChR) antibodies; however, several studies have reported that individuals with anti-gAChR antibodies present with central nervous system (CNS) symptoms such as impaired consciousness and seizures. In the present study, we investigated whether the presence of serum anti-gAChR antibodies correlated with autonomic symptoms in patients with functional neurological symptom disorder/conversion disorder (FNSD/CD).MethodsClinical data were collected for 59 patients presenting with neurologically unexplained motor and sensory symptoms at the Department of Neurology and Geriatrics between January 2013 and October 2017 and who were ultimately diagnosed with FNSD/CD according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition. Correlations between serum anti-gAChR antibodies and clinical symptoms and laboratory data were analyzed. Data analysis was conducted in 2021.ResultsOf the 59 patients with FNSD/CD, 52 (88.1%) exhibited autonomic disturbances and 16 (27.1%) were positive for serum anti-gAChR antibodies. Cardiovascular autonomic dysfunction, including orthostatic hypotension, was significantly more prevalent (75.0%vs34.9%,p= 0.008), whereas involuntary movements were significantly less prevalent (31.3%vs69.8%,p= 0.007), among anti-gAChR antibody-positive compared with - negative patients. Anti-gAChR antibody serostatus did not correlate significantly with the frequency of other autonomic, sensory, or motor symptoms analyzed.ConclusionsAn autoimmune mechanism mediated by anti-gAChR antibodies may be involved in the etiology of FNSD/CD in a subgroup of patients.

This report describes a 59-year-old woman who presented with progressive encephalomyelitis with rigidity and myoclonus (PERM)-like symptoms and severe dysautonomia, including orthostatic hypotension, sinus bradycardia, dysuria, and prolonged constipation. Her neurological symptoms improved after immunotherapy, but the dysautonomia persisted. Anti-ganglionic acetylcholine receptor (gAChR) α3 subunit antibodies, which are frequently identified in patients with autoimmune autonomic ganglionopathy, were detected in the pre-treatment serum. The central distribution of the nicotinic acetylcholine receptors, a target of anti-gAChR antibodies, and immunotherapeutic efficacy observed in this case indicate that anti-gAChR α3 subunit antibodies are associated with the PERM-like features accompanied by autonomic manifestations.

The importance of autonomic neurology has grown exponentially since the development of neuroscience, genetics, and immunology. Advances in this field have made it possible to elucidate the pathomechanism of dysautonomia and autonomic nervous system interactions in both health and disease. In the special issue ?Recent Advances in Autonomic Neurology,? four articles covering a wide range of topics in clinical neuroscience, including degenerative diseases, genetic disorders, immune-mediated neuropathy, and autoimmune encephalitis, were published. This review focused on presenting the recent progress in the clinical approaches for dysautonomia in autoimmune diseases, Ehlers-Danlos syndrome, myalgic encephalomyelitis/chronic fatigue syndrome, and coronavirus disease 2019 (COVID-19). Of particular current concern, is Long COVID, defined as the persistence of symptoms after 3 weeks from being infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), may involve autonomic dysfunction. The research and clinical practice for autonomic dysfunction in neurology is constantly evolving, which is exemplified by the current clinical research on Long COVID.

Objective To determine whether autonomic dysfunction in neurosarcoidosis is associated with anti-ganglionic acetylcholine receptor (gAChR) antibodies, which are detected in autoimmune autonomic ganglionopathy. Methods We retrospectively extracted cases of sarcoidosis from 1787 serum samples of 1,381 patients between 2012 and 2018. Anti-gAChR antibodies against the α3 and β4 subunit were measured by luciferase immunoprecipitation to confirm the clinical features of each case. We summarized literature reviews of neurosarcoidosis with severe dysautonomia to identify relevant clinical features and outcomes. Results We extracted three new cases of neurosarcoidosis with severe dysautonomia, among which two were positive for anti-gAChR antibodies: Case 1 was positive for antibodies against the β4 subunit, and Case 2 was positive for antibodies against both the α3 and β4 subunits. We reviewed the cases of 15 patients with neurosarcoidosis and severe dysautonomia, including the three cases presented herein. Orthostatic hypotension and orthostatic intolerance were the most common symptoms. Among the various types of neuropathy, small fiber neuropathy (SFN) was the most prevalent, with seven of nine cases exhibiting definite SFN. Six of eight cases had impaired postganglionic fibers, of which the present three cases revealed abnormality of 123I-MIBG myocardial scintigraphy. Of the 11 cases, 10 were responsive to immunotherapy, except one seropositive case (Case 2). Conclusions The presence of gAChR antibodies may constitute one of the mechanisms by which dysautonomia arises in neurosarcoidosis.

Objective Patients with acquired autonomic dysfunction may have antibodies specific to the ganglionic nicotinic acetylcholine receptor (gAChR). However, the clinical features of children and adolescents with acquired autonomic dysfunction (AAD) remain unclear. This study aimed to determine the clinical features of pediatric patients with acquired autonomic dysfunction. Methods This study retrospectively examined a series of patients of AAD with serum gAChR antibodies who were referred to our laboratory for antibody testing between January 2012 and April 2019. The study included 200 patients (

Postural orthostatic tachycardia syndrome (POTS) is a form of orthostatic intolerance characterized by symptoms such as lightheadedness, fainting, and brain fog that occur with a rapid elevation in heart rate when standing up from a reclining position. The etiology of POTS has yet to be established. However, a growing body of evidence suggests that POTS may be an autoimmune disorder such as autoimmune autonomic ganglionopathy, an acquired, immune-mediated form of diffuse autonomic failure. Many patients have serum antibodies that bind to the ganglionic acetylcholine receptors (gAChRs) in the autonomic ganglia. Herein, we describe a 39-year-old female patient with an eight-year history of orthostatic intolerance. POTS was diagnosed based on the findings of a head-up tilt test, in which a rapid increase in the patient's heart rate from 58 bpm in the lying position to 117 bpm in the upright position without orthostatic hypotension was observed. The POTS symptoms were refractory to various medications except for pyridostigmine bromide, which resulted in a partial resolution of her symptoms. Her serum was found to be strongly positive for anti-gAChR (β4 subunit) autoantibody (2.162 A.I., normal range: below 1.0). Based on these findings, a limited form of autoimmune POTS was diagnosed. After obtaining written informed consent, she was treated with intravenous immunoglobulin (IVIg) 400 mg/kg/day for five days, which led to clinical improvement by reducing her heart rate increase in the upright position. She was able to return to work with IVIg treatment at regular intervals. Our case provides further evidence of a potential autoimmune pathogenesis for POTS. Aggressive immunotherapy may be effective for POTS even in chronic cases.

In Kyudo (Japanese archery), there are four disorders that hinder an archer's performance: Hayake (releasing the bow too early), Motare (unable to release the bow when intended), Biku (jerking when aiming), and Yusuri (shaking when drawing the bow, or aiming). These disorders are similar to Yips, a psycho-neuromuscular movement disorder, recognized in various sports, but few studies have examined yips in Kyudo. This study examined the frequency, classification, and risk factors of yips in Kyudo among medical students. The results showed that 41 of 65 students (63.1%) experienced at least one disorder. The frequency of Hayake was the highest (35 patients; 85.3%). An experience of playing was associated with the increased risk of yips in Kyudo. Motare was the only disorder that appeared on its own, and without complications from other disorders. Based on its characteristics, it was suspected that task-specific focal dystonia involved in Motare.

Disaster countermeasures have been implemented by the Japanese Society of Neurology based on the experience of support to the areas affected by the Great East Japan Earthquake on March 11, 2011. The countermeasures activity began at the end of 2011. We, the Committee for Measures Against Disaster, officially started work in 2014. We developed a support network to urgently deal with patients with intractable neurological disease at the time of disaster and strengthen disaster measures, including effective disaster countermeasure training. During the 2016 Kumamoto earthquake, we realized the need to prepare for natural disasters, leading to a state of emergency, at normal times. A list of vulnerable people should be prepared and the individual support plan for disaster should be confirmed during normal times. Furthermore, during disaster, livelihood support is required for patients with intractable neurological disease living in evacuation centers in affected areas. Therefore, we compiled and published the book, titled "The manual of disaster countermeasures," in 2017. The Committee for Measures Against Disaster in the Japanese Society of Neurology has appointed a liaison officer for patients with intractable neurological disease in each prefecture. The liaison's role of is gathering and disseminating information on the disaster-hit areas, arranging medical support, and coordinating health activities, when natural disasters occur. It is hoped that the liaison officer will play an active role both at normal times and during disaster, even unforeseen ones. Although we hope for the best, we aim to be prepared for the worst.

Highlights • We describe the first case of binasal hemianopia due to bilateral optic perineuritis. • Bilateral optic perineuritis should be considered as a causative disease of binasal hemianopia. • Early diagnosis of optic perineuritis is crucial to avoid irreversible visual impairment.

Objective To characterize the inflammatory myopathy associated with programmed cell death 1 inhibitors (PD-1 myopathy). Methods We studied 19 Japanese patients with PD-1 myopathy (13 men and 6 women, mean age 70 years), who were referred to Keio University. As control groups, we used 68 patients with anti-signal recognition particle antibodies, 51 patients with anti-aminoacyl transfer RNA synthetase antibodies and 460 healthy subjects. Results In regard to muscle-disease severity, 10 patients showed a mild form of disease and 9 patients showed a severe form. Non-small cell lung cancer was the most common underlying cancer. PD-1 inhibitor consisted of 11 nivolumab and 8 pembrolizumab. PD-1 myopathy occurred 29 days on average after the first administration of PD-1 inhibitor. The initial manifestation of muscle weakness was ptosis in 10 patients, 15 patients had ptosis, 13 diplopia, 8 facial muscle weakness, 10 bulbar symptoms, 13 limb weakness, 14 neck weakness, 4 cardiac involvement, 6 respiratory involvement and 16 myalgia. Ocular, facial, cardiac and respiratory involvement and myalgia were more frequently observed than controls. Serum creatine kinase was increased to 5247 IU/L on average. Autoantibodies related to inflammatory myopathy were negative, while anti-striational antibodies were found in 13 (68%) patients. HLA-C*12:02 alleles were more frequently detected than healthy controls. Muscle pathology was characterized by multifocal necrotic myofibers with endomysial inflammation and expression of MHC class I. Immunosuppressive therapy with corticosteroids was generally effective for muscle weakness. Conclusions Based on our clinical, histological and immunological findings, PD-1 myopathy is a discrete subset of inflammatory myopathy.

In April of 2016, major earthquakes occurred in Kumamoto, Japan. There is limited information on how major earthquakes affect patients with Parkinson's disease (PD). This study investigates the effect of major earthquakes on patients with PD. The participants were outpatients with PD from hospitals located in areas heavily damaged by the earthquakes. We performed an anonymous survey at nine medical institutions to investigate the condition of these patients during the month following the earthquakes. We collected questionnaires from 335 patients with PD. The mean age was 72.6, and the mean disease duration was 7.4 years. Regarding physical conditions, 29.3% of the patients worsened, 1.5% improved, and 68.1% had no change. The mental health of 35.2% of the patients worsened, 2.4% improved, and 57.9% had no change. The most frequently exacerbated neurologic symptoms included bradykinesia (56.1%), gait disturbance (51.0%), freezing of gait (40.8%), extension of "off" time (38.8%), and constipation (38.8%). The worsening mental conditions included fear of an aftershock (77.1%), anxiety (49.2%), insomnia (47.5%), melancholy feelings (45.8%), and fatigability (38.1%). Patients forced to evacuate reported significantly more physical and mental health symptoms (p 0.01). The influences of major earthquakes on patients with PD were identified. After major earthquakes, we should consider the care required for patients' physical and mental health especially for those who experienced evacuation.

The purposes of the present study were to identify anti-striational antibodies in myasthenia gravis (MG) patients with myositis and/or myocarditis using a combination of cell-based assays and flow cytometry (cytometric cell-based assays) and to describe the main clinical implications. Among 2,609 stored samples collected from all over Japan between 2003 and 2016, we had serum samples from 30 MG patients with myositis and/or myocarditis. Cytometric cell-based assays with titin, ryanodine receptor, and voltage-gated Kv1.4 were performed. Autoantibodies were determined by differences in phycoerythin fluorescence between the 293F cells and titin-transfected cells. MG patients with myositis and/or myocarditis as well as late-onset and thymoma-associated MG had anti-titin, anti-ryanodine receptor, and anti-Kv1.4 antibodies. In contrast, patients with early-onset MG, those with other myopathies and healthy controls did not have anti-titin or anti-Kv1.4 antibodies with some exceptions, but they possessed anti-ryanodine receptor antibodies. Thirty MG patients with myositis and/or myocarditis showed a severe generalized form, and 21 of them had thymoma. Anti-titin and anti-Kv1.4 antibodies were found in 28 (93%) and 15 (50%) patients, respectively, and all patients had at least one of these antibodies. Cytometric cell-based assays thus demonstrated that anti-striational antibodies are biomarkers of MG with myositis and/or myocarditis.

Damage of the central and peripheral nervous systems associated with systemic lupus erythematosus (SLE) is termed neuropsychiatric SLE (NPSLE). In this review, we have discussed SLE encephalopathy, which is associated with neurological symptoms in particular. At the time of diagnosis, disease severity should be evaluated based on clinical findings, imaging, laboratory tests, including cerebrospinal fluid tests and neurophysiological tests, of the patient. Subsequently, treatment involving both definitive therapy and symptomatic treatment is initiated. After introducing definitive therapy, it is further desirable to adopt an appropriate treatment approach by identifying the predominant type of pathogenesis (inflammatory or vascular). A collaborative approach involving specialists in collagen vascular disease, neurologists, and psychiatrists is important for appropriate management of NPSLE.

BACKGROUND AND PURPOSE Neuromyelitis optica spectrum disorder (NMOSD) often presents in the elderly with an insidious onset of symptoms and aggressive progression. There have been anecdotal cases of very late onset (VLO)-NMOSD, but case series reports are rare. The aim of this retrospective study was to clarify the clinical features of VLO-NMOSD. METHODS According to the age at onset, we classified patients with NMOSD into three subgroups: ≤49 years, early onset NMOSD (EO-NMOSD); 50-69 years, late onset NMOSD (LO-NMOSD); and ≥70 years, VLO-NMOSD. We evaluated the clinical characteristics, magnetic resonance imaging (MRI) findings, laboratory data, and immunotherapies of the groups. RESULTS Overall, 12 men and 64 women with a median (interquartile range) age at onset and duration of disease of 42.0 (29.0-55.8) years and 70.0 (16.3-143.0) months, respectively, were included. Eight (11%) patients had VLO-NMOSD, 22 (29%) had LO-NMOSD, and 46 (61%) had EO-NMOSD. Patients with EO-NMOSD had a significantly longer interval between episodes as well as time between the first symptom and diagnosis of NMOSD than did those with VLO-NMOSD and LO-NMOSD (p = 0.046). Optic neuritis and nerve lesions on MRI were significantly less frequent in patients with VLO-NMOSD than in those with LO-NMOSD and EO-NMOSD (p = 0.002 and p = 0.028, respectively). In contrast, patients with VLO-NMOSD had higher nadir Expanded Disability Status Scale and Nurick scale scores and a significantly longer spinal lesion length than did those with LO-NMOSD and EO-NMOSD (p = 0.029, p = 0.049, and p = 0.032, respectively). CONCLUSIONS Patients with VLO-NMOSD tend to develop severe myelitis with long cord lesions but not optic neuritis.

The glial cells in the central nervous system express diverse inward rectifying potassium channels (Kir). They express multiple Kir channel subtypes that are likely to have distinct functional roles related to their differences in conductance, and sensitivity to intracellular and extracellular factors. Dysfunction in a major astrocyte potassium channel, Kir4.1, appears as an early pathological event underlying neuronal phenotypes in several neurological diseases. The autoimmune effects on the potassium channel have not yet been fully described in the literature. However, several research groups have reported that the potassium channels are an immune target in patients with various neurological disorders. In 2012, Srivastava et al. reported about Kir4.1, a new immune target for autoantibodies in patients with multiple sclerosis (MS). Follow-up studies have been conducted by several research groups, but no clear conclusion has been reached. Most follow-up studies, including ours, have reported that the prevalence of Kir4.1-seropositive patients with MS was lower than that in the initial study. Therefore, we extensively review studies on the method of antibody testing, seroprevalence of MS, and other neurological diseases in patients with MS. Finally, based on the role of Kir4.1 in MS, we consider whether it could be an immune target in this disease.

Autoimmune gastrointestinal dysmotility (AGID), an idiopathic or paraneoplastic phenomenon, is a clinical form of limited autoimmune dysautonomia. The symptoms of AGID and gastrointestinal manifestations in patients with autoimmune rheumatic diseases are overlapping. Antineuronal autoantibodies are often detected in patients with AGID. Autoantibodies play a key role in GI dysmotility; however, whether they cause neuronal destruction is unknown. Hence, the connection between the presence of these autoantibodies and the specific interference in synaptic transmission in the plexus ganglia of the enteric nervous system has to be determined. The treatment options for AGID are not well-defined. However, theoretically, immunomodulatory therapies have been shown to be effective and are therefore used as the first line of treatment. Nonetheless, diverse combined immunomodulatory therapies should be considered for intractable cases of AGID. We recommend comprehensive autoimmune evaluation and cancer screening for clinical diagnosis of AGID. Univocal diagnostic criteria, treatment protocols, and outcome definitions for AGID are required for prompt diagnosis and treatment and appropriate management of immunotherapy, which will circumvent the need for surgeries and improve patient outcome. In conclusion, AGID, a disease at the interface of clinical immunology and neurogastroenterology, requires further investigations and warrants cooperation among specialists, especially clinical immunologists, gastroenterologists, and neurologists.

Objective: To clarify the clinical features of very late-onset neuromyelitis optica spectrum disorders NMOSD (VLO-NMOSD).Methods: According to the age at onset, we classified patients with NMOSD into three subgroups of early-onset NMOSD (EO-NMOSD), late-onset NMOSD (LO-NMOSD), and VLO-NMOSD. We evaluated the clinical characteristics, MRI findings, laboratory data, and immunotherapies among the groups.Results: Overall, eight males and 36 females with a median age at onset of 43.00 years (interquartile range, 29.00–54.75) and median duration of disease of 6.00 months (interquartile range, 3.00–11.75) were included. This included 7 (16%) patients with VLO-NMOSD, 11 (25%) with LO-NMOSD, and 26 (59%) with EO-NMOSD. Patients with EO-NMOSD had significantly longer disease duration than those did with VLO-NMOSD and LO-NMOSD (p=0.015). Optic nerve lesions on MRI and optic neuritis were significantly less frequent in patients with VLO-NMOSD than in those with LO-NMOSD and EO-NMOSD (p=0.013 and p=0.046, respectively), whereas the length of the spinal lesion was significantly longer in those with VLO-NMOSD in comparison with those with LO-NMOSD and EO-NMOSD (p=0.038).Conclusions: Spinal cord lesion in patients with VLO-NMOSD was significantly longer despite short disease duration, and optic neuritis was significantly less frequent in them.

Background: Patients with systemic sclerosis (SSc) complicated by gastrointestinal dysmotility are difficult to treat and have high mortality. To clarify the pathogenesis of gastrointestinal manifestations, we aimed to demonstrate the association among the clinical features of SSc, the serological markers, the autoantibodies against nicotinic acetylcholine receptor at autonomic ganglia (gAChR). Methods: Fifty patients were enrolled and divided into two groups according to the presence or absence of gastrointestinal manifestations, and the characteristics were analyzed between these two groups. We measured biomarkers and the autoantibodies against two gAChRα3 and β4 subunits to test sera samples. Furthermore, patients were classified based on the presence or absence of anti-gAChR autoantibodies, and their clinical features were compared. Results: In patients with SSc and gastrointestinal manifestations, digital ulcers were more frequent (p = 0.050) and VEGF expression was significantly higher (p = 0.038). Seven subjects with SSc were seropositive for α3 subunit, whereas one patient was seropositive for β4 subunit. The mean level of anti-gAChRα3 autoantibodies in SSc patients with gastrointestinal manifestations was significantly higher than that in SSc patients without gastrointestinal manifestations (p = 0.001). The group of patients with SSc and gAChR autoantibodies had significantly higher endostatin levels (p = 0.046). Conclusions: This study is the first to demonstrate that clinical characteristics of SSc patients with seropositivity for gAChR autoantibodies. Patients with SSc have circulating autoantibodies against gAChR, which may contribute to gastrointestinal manifestations associated with this disease, suggesting that gAChR-mediated autonomic neurotransmission may provide a pathomechanism for gastrointestinal dysmotility in SSc., Arthritis Research and Therapy, 22(1), art.no.32; 2020

A 58-year-old Japanese woman with herpes zoster developed Behcet's disease (BD) with symptoms including orthostatic intolerance as an autonomic disorder. Multiple immune-suppressive therapies and a β-blocker successfully controlled both the disease activity of BD and the autonomic disorders. A cytokine multiplex analysis of her serum revealed the elevation of proinflammatory cytokines [interleukin (IL)-1, IL-6, IL-12, tumor necrosis factor alfa (TNFα), and interferon gamma (IFN-γ)] and a low IL-10 concentration. IL-10 production is reported to be important for defense against herpes zoster virus (VZV). Insufficient IL-10 production is reported in BD. The reactivation of VZV with this cytokine profile suggests that BD will develop with various symptoms, including severe autonomic disorders., Internal Medicine, 59(8), pp.1099-1104; 2020

Autonomic neuropathy has been reported in autoimmune rheumatic diseases (ARD) including Sjögren’s syndrome, systemic sclerosis, rheumatoid arthritis, and systemic lupus erythematosus. However, the pathophysiological mechanism underlying autonomic dysfunction remains unknown to researchers. On the other hand, autoimmune autonomic ganglionopathy (AAG) is an acquired immune-mediated disorder, which causes dysautonomia that is mediated by autoantibodies against ganglionic acetylcholine receptors (gAChRs). The purpose of this review was to describe the characteristics of autonomic disturbance through previous case reports and the functional tests used in these studies and address the importance of anti-gAChR antibodies. We have established luciferase immunoprecipitation systems to detect antibodies against gAChR in the past and determined the prevalence of gAChR antibodies in various autoimmune diseases including AAG and rheumatic diseases. Autonomic dysfunction, which affects lower parasympathetic and higher sympathetic activity, is usually observed in ARD. The anti-gAChR antibodies may play a crucial role in autonomic dysfunction observed in ARD. Further studies are necessary to determine whether anti-gAChR antibody levels are correlated with the severity of autonomic dysfunction in ARD.

We used an enzyme‐linked immunosorbent assay to measure pretreatment B cell‐activating factor belonging to the tumour necrosis factor family (BAFF) and transmembrane activator and CAML‐interactor (TACI) levels in CSF and serum collected from patients with primary central nervous system lymphoma (PCNSL) and control groups. The decision tree analysis of CSF TACI and BAFF levels for patients with a PCNSL diagnosis showed 100% sensitivity and 100% specificity when we attempted to differentiate PCNSL from glioblastoma and CNS inflammatory diseases. The combination of CSF TACI and BAFF levels may thus be a novel and useful diagnostic biomarker of PCNSL.

Immune checkpoint inhibitors sometimes cause neuromuscular adverse events. Although a few cases of myasthenia gravis with hyperCKemia triggered by immune checkpoint inhibitors have been described, conclusive evidence remains limited. We conducted a systematic review of published cases of myasthenia gravis with hyperCKemia related to immune checkpoint inhibitors. Moreover, we tested anti‐striational antibodies in the case of myasthenia gravis with myositis after nivolumab administration. We located 17 published case reports. Anti‐striational antibodies were tested in six cases and five cases were positive. Our systematic analyses revealed poor prognosis in myasthenia gravis combined hyperCKemia with immune checkpoint inhibitors.

PD-1 blockade therapy activates T cells by blocking the interaction between PD-1 and PD-L1 and promotes IFN-γ and Th1 cytokine production. In turn, IFN-γ and Th1 cytokines produced by activated T cells promote TF synthesis in monocytes/macrophages, which results in hypercoagulability leading to thrombosis.