The Presence of Ganglionic Acetylcholine Receptor Antibodies in Sera from Patients with Functional Gastrointestinal Disorders: A Preliminary Study.

BACKGROUND: Functional gastrointestinal disorders (FGIDs), including functional dyspepsia (FD) and irritable bowel syndrome (IBS), are characterized by chronic and recurrent gastrointestinal symptoms. Clinically, FD and IBS often resemble gastrointestinal dysmotility caused by autoimmune autonomic neuropathy. We examined the seropositive frequency of autoantibodies against ganglionic nicotinic acetylcholine receptors (gnAChRs) in patients presenting with FGIDs. OBJECTIVE: To elucidate the seropositivity of gnAChR antibodies and the clinical features of seropositive FD and IBS. MATERIALS AND METHODS: We measured autoantibodies against the gnAChR α3 and ß4subunits using luciferase immunoprecipitation systems. Serum samples from patients with any autonomic symptoms were obtained from hospitals in Japan between January 2012 and August 2018 (1787 serum samples of 1381 patients). We selected FD and IBS patients and compared the clinical characteristics and prevalence of autonomic symptoms between those with seropositive and seronegative IBS and FD. RESULTS: Nine IBS and two FD cases (one comorbid case with IBS) were found. We found four patients (36.4%) in whom gnAChR antibodies were positive in these eleven patients. Sicca symptoms were observed in three of four cases (75%) of seropositive FGID compared with zero of seven cases (0%) of seronegative FGID. CONCLUSIONS: We found patients with gnAChR antibodies in FD and IBS patients. These data will be valuable for elucidating the pathophysiology of these FGIDs and developing new treatment strategies.

Multicenter, randomized, double-blind, placebo-controlled phase 3 study of mogamulizumab with open-label extension study in a minimum number of patients with human T-cell leukemia virus type-1-associated myelopathy.

Human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic neurodegenerative disease. This multicenter, randomized phase 3 study evaluated the efficacy and safety of 0.3 mg/kg intravenous mogamulizumab, a monoclonal antibody targeting-CC chemokine receptor 4, every 12 weeks in HAM/TSP patients. This study comprised a 24-week double-blind, placebo-controlled period, 24-week open-label period, and extension treatment period. The primary endpoint was the proportion of patients with a ≥ 1-grade improvement in the Osame motor disability score (OMDS). Secondary endpoints were changes in HTLV-1 proviral load, 10-m timed walk, cerebrospinal fluid (CSF) neopterin levels, and safety. The exploratory endpoint was CSF chemokine C-X-C motif ligand 10 (CXCL10) levels. Thirty-four and 33 patients were randomized to mogamulizumab and placebo arms, respectively. At the end of the double-blind period, no significant difference was found in the OMDS improvement rate or other secondary efficacy endpoints assessing motor activities. However, the mogamulizumab arm showed a significant decrease in HTLV-1 proviral load (- 59.39 ± 29.91% vs. placebo 2.32 ± 36.31%) and CSF neopterin (p < 0.001)/CXCL10 levels (p = 0.004). The baseline OMDS pattern and the 60-80% HTLV-1 proviral load reduction were sustained through the open-label and extension treatment periods. Although a higher incidence of rash (69.2%) was reported, the safety profile was similar compared with a previous phase 1/2a study. We found no significant difference in clinical benefit; however, mogamulizumab may provide long-term clinical benefit by preventing disease progression, as CSF neopterin/CXCL10 levels are associated with long-term prognosis in HAM/TSP.Clinical Trial Registration Number: NCT03191526 (registered date: 6-June-2017).

Macroglossia in rapidly progressive inclusion body myositis.

Inclusion body myositis (IBM) is a refractory muscle disease characterized by inflammatory and degenerative features in myofibers. Macroglossia is common in systemic amyloid light chain amyloidosis; however, no reports have been published on patients with IBM. We encountered a female patient with clinicopathologically defined IBM who exhibited relatively rapid progression of dysphagia, gait disturbance, and macroglossia. Muscle biopsy demonstrated endomysial mononuclear inflammatory infiltrates, fiber necrosis and regeneration with rimmed vacuoles, and sarcoplasmic inclusions of p62. Tongue biopsy demonstrated fiber degeneration with fatty replacement and fibrosis, nonnecrotic fibers surrounded and invaded by mononuclear cells, and sarcoplasmic dotlike inclusions of p62. Based on the parotid gland, lip, and muscle biopsy, she was diagnosed as having IBM with Sjögren's syndrome. She was treated with steroid pulse and intravenous immunoglobulin therapy followed by oral administration of prednisolone, which resulted in temporary clinical improvement. Macroglossia might be an indicator of immunotherapy effectiveness.

A novel murine model of autoimmune dysautonomia by α3 nicotinic acetylcholine receptor immunization.

We aimed to establish a novel murine model of autoimmune autonomic ganglionopathy (AAG), which represents autoimmune dysautonomia, associated with MHC class II to understand its pathomechanism and the pathogenicity of nicotinic acetylcholine receptor (nAChR) antibodies. The amino acid sequence of the mouse nAChRα3 protein was analyzed using an epitope prediction tool to predict the possible MHC class II binding mouse nAChRα3 peptides. We focused on two nAChRα3 peptides in the extracellular region, and experimental AAG (EAAG) was induced by immunization of C57BL/6 mice with these two different peptides. EAAG mice were examined both physiologically and histologically. Mice with EAAG generated nAChRα3 antibodies and exhibited autonomic dysfunction, including reduced heart rate, excessive fluctuations in systolic blood pressure, and intestinal transit slowing. Additionally, we observed skin lesions, such as alopecia and skin ulcers, in immunized mice. Neuronal cell density in the sympathetic cervical ganglia in immunized mice was significantly lower than that in control mice at the light microscopic level. We interpreted that active immunization of mice with nAChRα3 peptides causes autonomic dysfunction similar to human AAG induced by an antibody-mediated mechanism. We suggested a mechanism by which different HLA class II molecules might preferentially affect the nAChR-specific immune response, thus controlling diversification of the autoantibody response. Our novel murine model mimics AAG in humans and provides a useful tool to investigate its pathomechanism.

Effectiveness of treatment for 31 patients with seropositive autoimmune autonomic ganglionopathy in Japan.

Background: Autoimmune autonomic ganglionopathy (AAG) is characterized by serum autoantibodies against the ganglionic acetylcholine receptor (gAChR). Immunomodulatory treatments may alleviate AAG symptoms, but the most appropriate treatment strategy is unclear. Objective: This study aimed to confirm the effectiveness of treatments, particularly immunotherapy, in patients with seropositive AAG in Japan, as well as to determine the most effective treatment and the best assessment method for clinical response to treatment. Methods: We collected data from a previous cohort study of patients with seropositive AAG. The clinical autonomic and extra-autonomic symptoms were objectively counted and subjectively assessed using the modified Composite Autonomic Symptom Score. Post-treatment changes in the gAChR antibody level were evaluated. Results: Thirty-one patients received immunotherapy. Among them, 19 patients received intravenous methylprednisolone; 27, intravenous immunoglobulin; 3, plasma exchange; 18, oral steroids; 2, tacrolimus; 1, cyclosporine; and 1, mycophenolate mofetil. Patients who received immunotherapy showed improvements in the total number of symptoms (from 6.2 ± 2.0 to 5.1 ± 2.0) and modified Composite Autonomic Symptom Score (from 37.4 ± 15.3 to 26.6 ± 12.8). Orthostatic intolerance, sicca, and gastrointestinal symptoms were ameliorated by immunotherapy. Immunotherapy decreased the antibody levels (gAChRα3 antibodies, from 2.2 ± 0.4 to 1.9 ± 0.4, p = 0.08; gAChRß4 antibodies, from 1.6 ± 0.1 to 1.0 ± 0.2, p = 0.002), but antibody levels increased in 10 patients despite immunotherapy. The rate of improvement in the total number of symptoms was higher in patients with combined therapy than in patients with non-combined therapy (70.7% vs 28.6%). Conclusions: The scores in many items on the rating scale decreased after immunotherapy in patients with seropositive AAG, particularly in the combined immunotherapy group. However, more accurate assessment scales for clinical symptoms and multicenter randomized, placebo-controlled prospective studies are warranted to establish future treatment strategies.

Intravenous cyclophosphamide treatment for systemic lupus erythematosus with severe autonomic disorders confirmed by head-up tilt table test: A case series.

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.

[Yips in Kyudo (Japanese archery): prevalence, classification, and aggravating factors].

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.

Association between neurosarcoidosis with autonomic dysfunction and anti-ganglionic acetylcholine receptor antibodies.

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 ß4 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 ß4 subunit, and Case 2 was positive for antibodies against both the α3 and ß4 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.

gAChR antibodies in children and adolescents with acquired autoimmune dysautonomia in Japan.

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 (<20 years, 20 cases; ≥20 years, 175 cases) with clinical features of AAD. RESULTS: Upon comparing pediatric and adult patients, we found that antecedent infection and autonomic symptoms at onset with gastrointestinal symptoms occurred more frequently in children with AAD. We confirmed that four children (20.0%) met the diagnostic criteria for postural orthostatic tachycardia syndrome (POTS). A significantly higher number of children than adults had POTS (P = 0.002). In addition, upper GI dysfunction was more prevalent in children than in adults (P = 0.042). In particular, nausea and vomiting occurred in 60.0% of children with AAD and in 21.1% of adults (P < 0.001). The frequency of paralytic ileus was significantly higher in children with AAD (20.0%) relative to adults (6.3%) (P = 0.030). Regarding extra-autonomic manifestations, encephalopathy was more frequent in children (15.0%) than in adults (1.1%) (P < 0.001). INTERPRETATION: Pediatric AAD patients have their own clinical characteristics, and these features may be unique to children and adolescents.

Autoimmune gastrointestinal dysmotility: the interface between clinical immunology and neurogastroenterology.

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.

Anti-Kir4.1 Antibodies in Multiple Sclerosis: Specificity and Pathogenicity.

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.

Antibodies to the α3 subunit of the ganglionic-type nicotinic acetylcholine receptors in patients with autoimmune encephalitis.

Since autonomic dysfunction is closely associated with autoimmune encephalitis (AE), the objective of this study was to determine the autonomic symptoms and the prevalence of anti-α3 subunit of the ganglionic-type nicotinic acetylcholine receptor (gAChRα3) antibodies in the patients with AE. We reviewed the clinical features of 19 AE patients, and specifically analyzed sera for anti-gAChRα3 antibodies using the luciferase immunoprecipitation system (LIPS) assay. Cardiovascular autonomic symptoms were found to be common in patients with AE, and hypersalivation was seen only in patients with NMDAR encephalitis. LIPS detected anti-gAChRα3 antibodies in the sera from patients with AE (5/29, 26%). This study is the first to demonstrate that clinical characteristics including autonomic symptoms of AE patients with seropositivity for gAChR autoantibodies. It will be important to verify the role of gAChR antibodies in autonomic dysfunction and brain symptoms to clarify the pathogenesis of AE.

Ganglionic Acetylcholine Receptor Antibodies and Autonomic Dysfunction in Autoimmune Rheumatic Diseases.

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.

Detecting gastrointestinal manifestations in patients with systemic sclerosis using anti-gAChR antibodies.

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 ß4 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 ß4 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.

Behçet's Disease with Severe Autonomic Disorders Developing after Herpes Zoster.

A 58-year-old Japanese woman with herpes zoster developed Behçet's disease (BD) with symptoms including orthostatic intolerance as an autonomic disorder. Multiple immune-suppressive therapies and a ß-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.

A comprehensive analysis of the clinical characteristics and laboratory features in 179 patients with autoimmune autonomic ganglionopathy.

The clinical importance of autoantibodies against the ganglionic acetylcholine receptor (gAChR) remains to be fully elucidated. We aimed to identify the clinical characteristics of autoimmune autonomic ganglionopathy (AAG) in patients with gAChR autoantibodies. For this cohort investigation, serum samples were obtained from patients with AAG between 2012 and 2018 in Japan. We measured the levels of autoantibodies against gAChRα3 and gAChRß4 and evaluated clinical features, as well as assessing the laboratory investigation results among the included patients. A total of 179 patients tested positive for antibodies, including 116 gAChRα3-positive, 13 gAChRß4-positive, and 50 double antibody-positive patients. Seropositive AAG patients exhibited widespread autonomic dysfunction. Extra-autonomic manifestations including sensory disturbance, central nervous system involvement, endocrine disorders, autoimmune diseases, and tumours were present in 118 patients (83%). We observed significant differences in the frequencies of several autonomic and extra-autonomic symptoms among the three groups. Our 123I-metaiodobenzylguanidine myocardial scintigraphy analysis of the entire cohort revealed that the heart-to-mediastinum ratio had decreased by 80%. The present study is the first to demonstrate that patients with AAG who are seropositive for anti-gAChRß4 autoantibodies exhibit unique autonomic and extra-autonomic signs. Decreased cardiac uptake occurred in most cases, indicating that 123I- metaiodobenzylguanidine myocardial scintigraphy may be useful for monitoring AAG. Therefore, our findings indicate that gAChRα3 and gAChRß4 autoantibodies cause functional changes in postganglionic fibres in the autonomic nervous system and extra-autonomic manifestations in seropositive patients with AAG.

CSF TACI and BAFF levels in patients with primary CNS lymphoma as novel diagnostic biomarkers.

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 in the onset of myasthenia gravis with hyperCKemia.

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.