Autoimmune Autonomic Ganglionopathy Research Articles

Autoimmune Autonomic Ganglionopathy and Acute Autonomic Sensory Neuropathy

Autoimmune autonomic ganglionopathy (AAG) and acute autonomic sensory neuropathy (AASN) are immune-mediated neuropathies that affect the autonomic and/or dorsal root ganglia. Autoantibodies against the nicotinic ganglionic acetylcholine receptor (gAChR) detected in the sera of patients with AAG play a key role in the pathogenesis of this condition. Notably, gAChR antibodies are not detected in the sera of patients with AASN. Currently, AAG and AASN are not considered to be on the same spectrum with regard to disease concept based on clinical symptoms and laboratory findings. However, extra-autonomic brain symptoms (including psychiatric symptoms and personality changes) and endocrine disorders occur in both diseases, which suggests shared pathophysiology between the two conditions.

Peripheral Neuropathy and Muscle Disorders as Immune-Related Adverse Events

Neurological immune-related adverse events (irAEs) associated with cancer treatment with immune checkpoint inhibitors (ICI) present diverse clinical characteristics. Neurological irAEs affect the peripheral nervous system and muscles more than they affect the central nervous system. Among the various subsets of peripheral neuropathies, polyradiculoneuropathy, which includes Guillain-Barre syndrome and chronic inflammatory demyelinating polyneuropathy, stands out as the most severe form, leading to significant muscle weakness. ICIs can induce dysautonomia, including autoimmune autonomic ganglionopathy. Autonomic neuropathy represents a neurological irAE. Neurological irAEs of neuromuscular junctions include myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS). Diagnosing MG or myositis independently can be challenging when they occur as irAEs. Myocarditis is sometimes observed as an irAE in patients with MG and can cause both severe heart failure and lethal arrhythmias, resulting in fatal outcomes. Anti-Kv1.4 antibodies are biomarkers of the severe form of MG and myocarditis. The administration of ICI in patients with small cell lung cancer increases the risk of LEMS. The distinction between LEMS is an irAE or a manifestation of paraneoplastic neurological syndrome is unclear as both conditions share common immunological mechanisms.

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

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. To elucidate the seropositivity of gnAChR antibodies and the clinical features of seropositive FD and IBS. We measured autoantibodies against the gnAChR α3 and β4subunits 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. 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. 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.

Autoimmune Autonomic Neuropathy: From Pathogenesis to Diagnosis.

Autoimmune autonomic ganglionopathy (AAG) is a disease of autonomic failure caused by ganglionic acetylcholine receptor (gAChR) autoantibodies. Although the detection of autoantibodies is important for distinguishing the disease from other neuropathies that present with autonomic dysfunction, other factors are important for accurate diagnosis. Here, we provide a comprehensive review of the clinical features of AAG, highlighting differences in clinical course, clinical presentation, and laboratory findings from other neuropathies presenting with autonomic symptoms. The first step in diagnosing AAG is careful history taking, which should reveal whether the mode of onset is acute or chronic, followed by an examination of the time course of disease progression, including the presentation of autonomic and extra-autonomic symptoms. AAG is a neuropathy that should be differentiated from other neuropathies when the patient presents with autonomic dysfunction. Immune-mediated neuropathies, such as acute autonomic sensory neuropathy, are sometimes difficult to differentiate, and therefore, differences in clinical and laboratory findings should be well understood. Other non-neuropathic conditions, such as postural orthostatic tachycardia syndrome, chronic fatigue syndrome, and long COVID, also present with symptoms similar to those of AAG. Although often challenging, efforts should be made to differentiate among the disease candidates.

Autoantibodies against gAChR in humans and mouse models of autoimmune autonomic ganglionopathy

AbstractThe ganglionic nicotinic acetylcholine receptor (gAChR) mediates fast synaptic transmission in all peripheral autonomic ganglia (sympathetic, parasympathetic, and enteric). Over the last two decades, evidence has accumulated for a role of autoantibodies against gAChR in the development of autoimmune autonomic ganglionopathy (AAG). In this review we provide an updated overview of the field, with a highlight on the role of autoimmunity against gAChR in the pathogenesis of AAG. Clinical data as well as findings from experimental disease models are summarized in sections focusing on the presence of autoantibodies against gAChR in patients with AAG, the function of gAChR antibodies, the association of antibodies against gAChR with AAG‐related phenotypes, the in vivo pathogenicity of transferred autoantibodies against gAChR in mice, and mouse models of the disease induced by immunization with the nicotinic AChR. Based on a comprehensive assessment of the currently available data, we propose a hypothetical model for the role of autoantibodies against gAChR in the pathogenesis of AAG.

A Case of Liver Cancer with Overlapping Myasthenia Gravis, Myocarditis, Seronegative Autoimmune Autonomic Ganglionopathy, and Myositis Symptoms Induced by Atezolizumab: A Case Report.

An 83-year-old man with hepatocellular carcinoma developed muscle weakness, ptosis, and dyspnea 3 weeks after receiving atezolizumab. Soon after, mechanical ventilation was initiated, which was followed by marked blood pressure spikes. The levels of creatine kinase and troponin-I were significantly elevated, and acetylcholine receptor antibodies were positive. The patient was diagnosed with immune checkpoint inhibitor (ICI)-induced myositis, myasthenia gravis (MG), myocarditis, and suspected autoimmune autonomic ganglionopathy (AAG). After immunotherapy, the serum markers and blood pressure normalized, and he was weaned from the ventilator after five months. To our knowledge, this is the first reported case of AAG secondary to ICI-induced myositis, MG, and myocarditis.

S4324 A Case of Autoimmune Autonomic Ganglionopathy Presenting as Gastroparesis With Seropositive Anti-VGKC Antibodies

S4324 A Case of Autoimmune Autonomic Ganglionopathy Presenting as Gastroparesis With Seropositive Anti-VGKC Antibodies

Autoimmune Autonomic Ganglionopathy: Solving the 10 Assignments

Autoimmune autonomic ganglionopathy (AAG) is a rare acquired immune-mediated neurological disease that causes various autonomic symptoms. AAG is induced by autoantibodies for the α3 and β4 subunits of the ganglionic acetylcholine receptor (gAChR). gAChR antibodies mediate synaptic transmission in all autonomic ganglia, resulting in dysautonomia. Recent clinical and basic research topics in AAG include the following: 1)analysis of clinical features; 2)novel methods for gAChR antibody detection; 3)efficacy of combined immunotherapy; 4)novel experimental AAG; 5)COVID-19 and mRNA COVID-19 vaccination and its association with autonomic dysfunction; and 6)dysautonomia as an immune-related adverse event of immune checkpoint inhibitors in cancer therapy. The author and his collaborators have previously established "10 assignments" to understand the basic research and clinical issues of AAG. In this review, the author describes the current status of research on each of the "10 assignments," incorporating research trends over the last five years.

Dysautonomia associated with immune checkpoint inhibitors.

The purpose of this study is to report the clinical characteristics of dysautonomia associated with immune checkpoint inhibitors (ICIs). We reported two patients with autoimmune autonomic ganglionopathy (AAG) occurring as immune-related adverse events (irAEs). We also performed a review of previous case reports presenting dysautonomia during ICI therapy. Moreover, we conducted pharmacovigilance analyses using the US Food and Drug Administration Adverse Events Reporting System (FAERS) to investigate dysautonomia associated with ICI. Two patients in our care developed both AAG and autoimmune encephalitis following ICI therapy for lung cancers. We comprehensively reviewed 13 published cases (M:F = 11:2, mean onset age of 53years) with ICI-associated dysautonomia including AAG (n = 3) and autonomic neuropathy (n = 10). Of these, ICI monotherapy was performed in seven and combination ICI use in six. In 6 of 13 patients, dysautonomia appeared within one month after the start of ICIs. Orthostatic hypotension was observed in 7 and urinary incontinence or retention in five. All patients except three showed gastrointestinal symptoms. Anti-ganglionic acetylcholine receptor antibodies were undetectable. All but two patients received immune-modulating therapy. Immuno-modulating therapy was effective in three patients with AAG and two patients with autonomic neuropathy, but ineffective in the others. Five patients died, of either the neurological irAE (n = 3) or cancer (n = 2). The pharmacovigilance analyses using FAERS showed that ipilimumab monotherapy and the combination of nivolumab and ipilimumab constituted significant risks for developing dysautonomia, consistent with the review of literature. ICIs can cause dysautonomia including AAG, and autonomic neuropathy is a neurological irAE.

Anti-ganglionic acetylcholine receptor antibodies in functional neurological symptom disorder/conversion disorder.

Autoimmune 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). Clinical 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. Of 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 vs. 34.9%, P = 0.008), whereas involuntary movements were significantly less prevalent (31.3 vs. 69.8%, 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. An autoimmune mechanism mediated by anti-gAChR antibodies may be involved in disease etiology in a subgroup of FNSD/CD patients.

Combination of immunotherapy and Kampo medicines for a patient with autoimmune autonomic ganglionopathy

Combination of immunotherapy and Kampo medicines for a patient with autoimmune autonomic ganglionopathy

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.

Novel Cell-Based Assay for Alpha-3 Nicotinic Receptor Antibodies Detects Antibodies Exclusively in Autoimmune Autonomic Ganglionopathy.

Background and ObjectivesAutoantibodies against α3-subunit–containing nicotinic acetylcholine receptors (α3-nAChRs), usually measured by radioimmunoprecipitation assay (RIPA), are detected in patients with autoimmune autonomic ganglionopathy (AAG). However, low α3-nAChR antibody levels are frequently detected in other neurologic diseases with questionable significance. Our objective was to develop a method for the selective detection of the potentially pathogenic α3-nAChR antibodies, seemingly present only in patients with AAG.MethodsThe study involved sera from 55 patients from Greece, suspected for autonomic failure, and 13 patients from Italy diagnosed with autonomic failure, positive for α3-nAChR antibodies by RIPA. In addition, sera from 52 patients with Ca2+ channel or Hu antibodies and from 2,628 controls with various neuroimmune diseases were included. A sensitive live cell-based assay (CBA) with α3-nAChR–transfected cells was developed to detect antibodies against the cell-exposed α3-nAChR domain.ResultsTwenty-five patients were found α3-nAChR antibody positive by RIPA. Fifteen of 25 patients were also CBA positive. Of interest, all 15 CBA-positive patients had AAG, whereas all 10 CBA-negative patients had other neurologic diseases. RIPA antibody levels of the CBA-negative sera were low, although our CBA could detect dilutions of AAG sera corresponding to equally low RIPA antibody levels. No serum bound to control-transfected cells, and none of the 2,628 controls was α3-CBA positive.DiscussionThis study showed that in contrast to the established RIPA for α3-nAChR antibodies, which at low levels is of moderate disease specificity, our CBA seems AAG specific, while at least equally sensitive with the RIPA. This study provides Class II evidence that α3-nAChR CBA is a specific assay for AAG.Classification of EvidenceThis study provides Class II evidence that an α3-nAChR cell-based assay is a more specific assay for AAG than the standard RIPA.

Subunit-specific autoantibodies in autoimmune autonomic ganglionopathy

Autoimmune Autonomic Ganglionopathy (AAG) is a disorder that causes autonomic failure and is associated with alpha3-ganglionic acetylcholine-receptor (gnACHR) antibodies. Assays that detect antibodies to whole gnACHR or subunits are available. We compared in-house subunit-specific immunoassays using bacterially-expressed alpha3 and beta4 subunits against an immunomodulation assay to detect antibodies in patients with AAG or control groups in a novel 2-step clinical-characteristic unblinding protocol. Only 1/8 patients with seropositive-AAG had subunit-specific antibodies, with sensitivity, specificity, false-negative and positive rates of 12.5, 85.2, 78.6 and 13.4% respectively. Subunit-specific antibody-derived false-positive results can lead to misdiagnosis, as autonomic failure is not specific to AAG.

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; gAChRβ4 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.

Over 5 years follow-up of three cases of autoimmune autonomic ganglionopathy

We report the clinical course of three cases of anti-ganglionic acetylcholine receptor (gAChR) antibody positive auto-immune autonomic ganglionopathy (AAG) that have been followed for over 5 years. In all three cases, the symptoms improved by acute treatment, but ultimately relapsed. The first case was a female in her 20s who had a chronic history of photophobia, constipation and amenorrhea. The symptoms almost disappeared by plasma exchange, and menstruation resumed. During the course, it relapsed once after a cold. There was no recurrence of AAG during the two pregnancies. The second case was a male in his 60s who visited a hospital for the acute onset of orthostatic hypotension (OH) and psychological symptoms (infantilization and psychogenic pseudosyncope). Although IVIg was effective, it recurred frequently and was difficult to treat. However, all the symptoms disappeared eight years after the onset without any particular reasons. The third case was a female in her 80s who had a chronic history of OH. Acute treatment was effective, but AAG recurred repeatedly. Additionally, it was difficult to judge relapse because of the residual sequelae. During the course, cerebral hemorrhage due to supine hypertension or short-time blood pressure variability and femoral neck fracture caused by OH occurred. She eventually became a wheelchair. This report is clinically important because there are few reports of long-term follow-up of AAG.

First Case of Association between Autoimmune Autonomic Ganglionopathy (AAG) and Myeloproliferative Neoplasms (MPNs)

IntroductionAutoimmune autonomic ganglionopathy (AAG) is a rare disease that presents with different autonomic symptoms and positive autoantibodies against the ganglionic acetylcholine receptor (gAChR) in 50 % of the cases. Eighty percent of seropositive patient has extra-autonomic manifestations. Extra-autonomic manifestations include sensory disturbance, central nervous system involvement, endocrine disorders autoimmune diseases, and cancers. It has been reported with various malignancies, such as small lung cancer, thymoma, ovarian tumors and others.MethodWe report a case from MD Anderson cancer center (MDACC) and to our knowledge it is first case in literature of a patient Autoimmune autonomic ganglionopathy associated with primary myelofibrosisResultA 55-year-old African American male diagnosed with JAK2 V617F positive primary myelofibrosis in 2005 and placed on observation until September 2012 when he was referred to MDACC for further management. He was started on protocol with Ruxolitinib + lenalidomide and did well initially, but during the course of treatment, he started to experience leg weakness. Initially in the left leg and then the right leg. lenalidomide was placed on hold and in April 2015, ruxolitinib was held as well. On examination he has left leg weakness in addition to weak hand grip on the same side.On Further evaluation, he was diagnosed with inclusion body myositis after muscle biopsy He was then lost to follow up and followed with outside hematologistIn February 2020, he developed cytopenias and was referred back to MDACC for management. He was seen and we performed a bone marrow shortly thereafter. He continued to have PMF, molecular, cytogenetics could not be performed on bone marrow due to dry tap. Patient started on “investigational agent. In early 2021 patient started to have orthostatic hypotension and syncope. Serum paraneoplastic antibody panel revealed acetylcholine Receptor Gang Neuronal Ab.The above finding along with his automimic symptoms consists with diagnosis of autoimmune autonomic ganglionopathy.ConclusionAutoimmune autonomic ganglionopathy (AAG) with extra-autonomic manifestations is a very rare and not well known. It is reported before to be associated with solid malignancy, we describe here first association with hematological malignancy which is primary myelofibrosis. We aim to add this to literature, and to increase the knowledge and awareness of both hematologists and neurologists about this association and possible other hematological malignancies may be reported in the future DisclosuresVerstovsek: Celgene: Consultancy, Research Funding; CTI BioPharma: Research Funding; Genentech: Research Funding; Promedior: Research Funding; PharmaEssentia: Research Funding; Ital Pharma: Research Funding; Protagonist Therapeutics: Research Funding; Roche: Research Funding; Gilead: Research Funding; Incyte Corporation: Consultancy, Research Funding; NS Pharma: Research Funding; Blueprint Medicines Corp: Research Funding; AstraZeneca: Research Funding; Novartis: Consultancy, Research Funding; Sierra Oncology: Consultancy, Research Funding; Constellation: Consultancy; Pragmatist: Consultancy.

M151 A RARE CASE OF AUTOIMMUNE AUTONOMIC GANGLIONOPATHY

Autoimmune autonomic ganglionopathy (AAG) is a rare disease mediated by antibodies causing severe orthostatic-hypotension. Due to its unique presentation, patients can go undiagnosed causing them profound disability and poor-quality of life. Our case of AAG presenting in a 69-year-old-female illustrates the importance of including AAG in the differential diagnosis for patients who present with autonomic dysfunction.

Paraneoplastic autoimmune autonomic ganglionopathy as a debut of a bladder urothelial carcinoma: A case report

Autoimmune autonomic ganglionopathy (AAG) is a rare immune-mediated disorder associated with anti-α3 subunit of the ganglionic-type nicotinic acetylcholine receptor (anti-gAChRα3) antibodies, which bind to the acetylcholine-receptor in autonomic ganglia (parasympathetic and sympathetic), leading to autonomic failure. This disorder is mostly associated with viral infections, but it can also be associated with systemic malignancies. Here, we report the first case of a paraneoplastic autonomic ganglionopathy as a debut of a bladder urothelial carcinoma.

S2186 Autoimmune Autonomic Ganglionopathy Presenting as Constipation

S2186 Autoimmune Autonomic Ganglionopathy Presenting as Constipation