Waka Sakai

Clinical Features of Autoimmune Autonomic Ganglionopathy and the Detection of Subunit-Specific Autoantibodies to the Ganglionic Acetylcholine Receptor in Japanese Patients

Autoimmune autonomic ganglionopathy (AAG) is a rare acquired channelopathy that is characterized by pandysautonomia, in which autoantibodies to ganglionic nicotinic acetylcholine receptors (gAChR) may play a central role. Radioimmunoprecipitation (RIP) assays have been used for the sensitive detection of autoantibodies to gAChR in the serum of patients with AAG. Here, we developed luciferase immunoprecipitation systems (LIPS) to diagnose AAG based on IgGs to both the α3 and β4 gAChR subunits in patient serum. We reviewed the serological and clinical data of 50 Japanese patients who were diagnosed with AAG. With the LIPS testing, we detected anti-α3 and -β4 gAChR antibodies in 48% (24/50) of the patients. A gradual mode of onset was more common in the seropositive group than in the seronegative group. Patients with AAG frequently have orthostatic hypotension and upper and lower gastrointestinal tract symptoms, with or without anti-gAChR. The occurrence of autonomic symptoms was not significantly different between the seropositive and seronegative group, with the exception of achalasia in three patients from the seropositive group. In addition, we found a significant overrepresentation of autoimmune diseases in the seropositive group and endocrinological abnormalities as an occasional complication of AAG. Our results demonstrated that the LIPS assay was a useful novel tool for detecting autoantibodies against gAChR in patients with AAG.

Application of long-range polymerase chain reaction in the diagnosis of X-linked dystonia–parkinsonism

Sir, X-linked dystonia–parkinsonism (XDP, DYT3, also referred to as “Lubag”) is a neurodegenerative disorder characterized by a unique combination of parkinsonism and dystonia [1]. The insertion of short interspersed nuclear element, variable number of tandem repeats, and Alu composite (SVA) retrotransposon has been identified in intron 32 of the TATA-binding protein-associated factor 1 gene (TAF1), which is mapped within the haploblock associated with XDP [2]. Several disease-specific single-nucleotide changes (DSCs) and 48-bp deletion polymorphism have also been mapped within the haploblock [3]. The DSC3, located at the TAF1/DYT3 multiple transcript system, has been investigated and shown to be associated with XDP [4]. TAF1 is a component of the transcription initiation factor TFIID which plays a central role in mediating promoter responses to various activators and repressors [5]. DSC3 containing transcripts as well as alterations of TAF1 splice variants would affect the transcription of several genes, eventually leading to neurodegeneration [2, 4]. Genetic testing for XDP has been performed using Southern analysis for SVA retrotransposon or direct polymerase chain reaction

Ganglionic acetylcholine receptor autoantibodies in patients with autoimmune diseases including primary biliary cirrhosis

Abstract Objectives: Autonomic dysfunction is closely associated with autoimmune diseases (AID) including primary biliary cirrhosis (PBC). The objective of this study was to determine the prevalence of anti-ganglionic (nicotinic) acetylcholine receptor (gAChR) antibodies in patients with AID. Methods: We determined the presence of gAChR antibodies in serum samples from 146 patients (systemic lupus erythematosus [SLE] = 32; rheumatoid arthritis [RA] = 43; systemic sclerosis [SSc] = 38; PBC= 33) without information regarding autonomic symptoms, as well as 34 patients with other neurological diseases [OND], and 73 healthy controls [HC]. We specifically analyzed sera for anti-gAChRα3 and -β4 antibodies using the luciferase immunoprecipitation system (LIPS) assay. Results: LIPS assay detected anti-gAChRα3 and -β4 antibodies in the sera from patients with SLE (12.5%, 4/32), RA (18.6%, 8/43), SSc (13.2%, 5/38), PBC (9.1%, 3/33), OND (2.9%, 1/34), and HC (0.0%, 1/73). There were no significant correlations between the levels of anti-gAChRα3 and -β4 antibodies, and the total titers of autoantibodies in AID. Conclusions: The results demonstrated a significant prevalence of anti-gAChR antibodies in patients with AID, which is independent of the production of other autoantibodies in patients with autoimmune diseases. These anti-gAChR antibodies could mediate the autonomic dysfunction involved in the autoimmune mechanisms of AID.

Lack of KIR4.1 autoantibodies in Japanese patients with MS and NMO

Objectives: To examine anti-KIR4.1 antibodies by 2 different assays in Japanese patients with multiple sclerosis (MS) or neuromyelitis optica (NMO). Methods: One hundred sixty serum samples from 57 patients with MS, 40 patients with NMO/NMO spectrum disorder (NMOSD), and 50 healthy controls (all were Japanese) were tested with ELISA using a synthetic peptide of the first extracellular portion of human KIR4.1. In addition, we attempted to detect anti-KIR4.1 immunoglobulin G in the serum by the luciferase immunoprecipitation systems (LIPS) with the full length of human KIR4.1 produced in a human cell line, which is highly sensitive to single or multiple epitopes. Results: We failed to detect antibodies to the peptide fragment KIR4.183–120 in any case of MS and NMO/NMOSD using ELISA. Antibodies to the recombinant full length of KIR4.1 protein were detected in only 2 patients with MS and none in the patients with NMO/NMOSD by the LIPS assay. Conclusions: We developed 2 different methods (ELISA and LIPS) to measure autoantibodies to KIR4.1 in serum. We detected anti-KIR4.1 immunoglobulin G at a very low frequency in Japanese patients with MS or NMO/NMOSD. Serologic testing for human KIR4.1-specific antibodies is unlikely to improve the diagnosis of MS or NMO/NMOSD in Japanese patients.

Insights from the ganglionic acetylcholine receptor autoantibodies in patients with Sjögren’s syndrome

Abstract Objective: It is not known whether autonomic neuropathy is a feature of Sjögren’s syndrome (SS) or whether it is related to circulating antiganglionic acetylcholine receptor (gAChR) antibodies. The goal of the present study was to investigate the autonomic dysfunction in patients with SS and the associations between autonomic dysfunction, anti-gAChR antibodies, and clinical features of SS. Methods: (1) The first observational study tested for the presence of gAChR antibodies in the serum samples from 39 patients with SS (absent information regarding autonomic symptoms) and healthy volunteers. (2) In the second study, serological and clinical data from 10 Japanese patients diagnosed with SS were reviewed. These patients showed autonomic dysfunction, and luciferase immunoprecipitation systems (LIPS) test was conducted to detect anti-α3 and anti-β4 gAChR antibodies. (3) In the final analysis, we combined the data of seropositive SS patients with autonomic symptom from the first study with all of the patients from the second study, and analyzed the clinical features. Results: (1) The LIPS assay revealed that anti-gAChRα3 and anti-gAChRβ4 antibodies were detected in the sera from patients with SS (23.1%, 9/39). Five of nine SS patients had autonomic symptoms. (2) Anti-α3 and anti-β4 gAChR antibodies were also detected in 80.0% (8/10) of patients with SS with autonomic symptoms. Six of the ten patients were diagnosed as having SS after neurological symptoms developed. These seropositive patients had predominant and severe autonomic symptoms and were diagnosed with autonomic neuropathy. (3) Thirteen of fifteen SS patients with autonomic symptoms (86.7%) were seropositive for anti-gAChR antibodies, and we confirmed sicca complex, orthostatic hypotension, upper and lower gastrointestinal (GI) symptoms, and bladder dysfunction at high rates. Conclusion: The present results suggest the possibility of anti-gAChR antibodies aiding the diagnostics of SS with autonomic dysfunction.

抗利尿ホルモン分泌異常症候群で発症し，橋中心・橋外髄鞘崩壊症を合併した視神経脊髄炎関連疾患の1例

A 36-year-old woman complained of general malaise. She presented with hyponatremia and plasma osmotic pressure was lower than urinary osmotic pressure. In addition, serum antidiuretic hormone level was higher than the measurement sensitivity. She was diagnosed with the syndrome of inappropriate antidiuretic hormone secretion (SIADH). She fell into a coma despite correction of serum sodium level. Brain magnetic resonance imaging (MRI) revealed high signal intensities in the cerebral cortex, striatum, thalamus, hypothalamus, midbrain, and pons in fluid-attenuated inversion recovery images. Spinal MRI revealed a longitudinally extending lesion in the cervical cord. Serum sample was positive for anti-aquaporin-4 antibody, supporting the diagnosis of neuromyelitis optica spectrum disorder (NMOSD) combined with central pontine and extrapontine myelinolysis. In patients with NMOSD, the immune reaction can gradually cause destructive changes of the hypothalamus and lead to unstable ADH secretion in the absence of immunomodulatory treatment.

Memory B cell resurgence requires repeated rituximab in myasthenia gravis

The immunologic effects of rituximab (RTX) in myasthenia gravis (MG) remain to be explored. We aimed to clarify immunologic reactions and their association with response to RTX in MG. Regulatory T cell and B cell profiles of MG patients were monitored. Two patients presenting with generalized MG with anti-acetylcholine receptor antibodies were treated with RTX. The treatment led to sustained clinical improvement, discontinuation of intravenous immunoglobulin or plasma exchange, and reduction of prednisolone and other drugs. One patient was in remission for more than one year, whereas the other patient exhibited deterioration of symptoms within one year. Disease activity was associated with the repopulation of IgD-CD27- and IgD-CD27+ memory B cells. Clinicians should be aware of the possibility that MG ranges in the duration of B cell depletion and additional RTX should be prescribed upon resurgence of memory B cells.

Ganglionic acetylcholine receptor autoantibodies in patients with Guillain-Barré syndrome.

OBJECTIVES Although standardized autonomic tests are useful for diagnosing autonomic failure in patients with Guillain-Barré syndrome (GBS), they cannot be used as predictive markers. Thus, serological markers may correctly identify patients with GBS who are at risk for autonomic dysfunction. METHODS We validated a luciferase immunoprecipitation system that detects IgG antibodies in patient serum that specifically bind to the α3 or β4 subunits of ganglionic neuronal nicotinic acetylcholine receptors (gAChR). We then used luciferase-conjugated ligands specific to antibodies against two gAChR subunits to test 79 sera samples from patients with GBS, 34 from subjects with other neurological diseases (OND), and 73 from healthy controls (HC). 1) In the first analysis, patients were classified into two groups according to the presence or absence of autonomic symptoms (AS). We compared the frequency of the anti-gAChR antibodies between these two groups (AS+ and AS-). 2) In the second analysis, furthermore, patients were classified depending on the presence or absence of anti-glycolipid antibodies (AGA). We compared the frequency of the anti-gAChR antibodies between the four categories of GBS (AS+/AGA+, AS+/AGA-, AS-/AGA+, and AS-/AGA-), OND, and HC. RESULTS Eight subjects with GBS were positive for α3 subunits, while one was positive for β4 subunits. Anti-α3 and -β4 gAChR antibodies were also detected in 13.6% of AS+ GBS group in the first analysis. Two of 35 patients in AS-GBS group were seropositive for the anti-gAChR antibodies and AGA in the second analysis. Patients with GBS that were positive for serum antibodies to the α3 and/or β4 subunits of gAChRs showed a range of clinical features including AS and AGA. CONCLUSIONS Patients with GBS may have circulating antibodies against gAChR, which may contribute to the autonomic dysfunction associated with this disease.

The Cross-Sectional Area of Paraspinal Muscles Predicts the Efficacy of Deep Brain Stimulation for Camptocormia

BACKGROUND Camptocormia, a disturbance of posture, is a well-described clinical feature of PD and other parkinsonian syndromes. Previous reports have shown that DBS of the subthalamic nucleus (STN) or globus pallidus internus is effective in treating camptocormia. However, the efficacy of DBS for camptocormia varies. OBJECTIVE To determine a clinical marker for selecting an appropriate therapy for camptocormia, a disabling manifestation of Parkinsons disease (PD) that has a variable response to systemic and local therapies. METHODS We obtained pre-operative lumbar magnetic resonance imaging of 14 consecutive PD patients with camptocormia who underwent subthalamic nucleus deep brain stimulation (STN-DBS) in this retrospective-designed study. Lumbar MRI was performed three to six months prior to the operation. We measured the cross-sectional area (CSA) and width of each participants paraspinal muscles. RESULTS Four (28.6%) patients were effective (EF), five (35.7%) were partially effective (PE), and five (35.7%) were non-effective (NE) to STN-DBS. The lumbar paraspinal CSA and width were significantly larger in the EF group than in the PE and NE groups. CONCLUSIONS The CSA of paraspinal muscles and erector spinae width can be good predictive markers for improving camptocormia in patients with PD after deep brain stimulation.

Predictors of Neurologic Deterioration in Patients with Small-Vessel Occlusion and Infarcts in the Territory of Perforating Arteries

BACKGROUND It is difficult to predict neurologic deterioration in patients with small-vessel occlusion (SVO), that is, small infarcts in the territory of cerebral perforating arteries. METHODS We reviewed 110 patients with SVO who were admitted to our hospital. We divided them into groups with (n = 32, group 1) and without deterioration (n = 78, group 2) and evaluated their medical records, risk factors, magnetic resonance imaging findings, grade of periventricular hyperintensity (PVH), maximum diameter of the infarct area, and the number of slices showing infarcts on diffusion-weighted images (DWI). RESULTS Our study population consisted of 110 patients (71 males and 39 females; mean age 69.2 years): 32 (29%) did and 78 (71%) did not suffer deterioration. By univariate analysis, the age, current smoking, history of stroke, maximum diameter of the infarcted area, number of DWI slices with infarcts, frequency of PVH, and PVH grade based on Fazekas classification differed significantly between the 2 groups. By multivariate analysis, conventional risk factors other than PVH and history of stroke were not associated with neurologic deterioration (PVH grade ≥ 2 versus PVH grade ≤ 1, odds ratio 6.72, P = .006; with stroke versus without stroke, odds ratio .21, P = .049). We also found that higher the PVH grade, the worse the National Institutes of Health Stroke Scale score at the time of discharge. CONCLUSIONS PVH and without history of stroke are independently associated with neurologic deterioration in patients with SVO.