Markedly upregulated serum semaphorin 4A as a novel activity marker of myasthenia gravis.

Myasthenia gravis (MG) is an autoantibody-mediated disease of the neuromuscular junction. Semaphorin 4A (Sema4A) is involved in the activation of T cells in various inflammatory disorders. In this study, we aimed to investigate whether Sema4A is involved in the pathogenesis of MG. We measured serum Sema4A concentrations in 30 treatment-naïve MG patients with acetylcholine receptor (AChR) antibodies, 7 with muscle-specific tyrosine kinase (MuSK) antibodies and 21 normal controls. As a result, serum Sema4A levels were significantly higher in patients with AChR antibody-positive MG and MuSK antibody-positive MG than in controls (p ≤ 0.0001 for both MG groups). Serum Sema4A levels were correlated with AChR antibody levels (Spearman's ρ = 0.39, p = 0.03) and MG Foundation of America clinical classification classes (Spearman's ρ = 0.38, p = 0.04) in patients with AChR antibody-positive MG. In conclusion, high serum Sema4A levels may reflect T-cell activation, and this molecule could be a potential marker of disease activity in MG.

Long-term disability progression in aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder: a retrospective analysis of 101 patients.

BACKGROUND: Anti-aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4Ab+NMOSD) is an inflammatory disorder of the central nervous system with relapse-dependent progression. Few studies have reported the effects of prednisolone and biologics on disability progression in AQP4Ab+NMOSD, although it is established that they prevent clinical relapses. This retrospective study investigated long-term disability progression and the effects of therapeutic interventions on disability progression in AQP4Ab+NMOSD. METHODS: This study included a total of 101 patients with AQP4Ab+NMOSD. Disease progression was investigated in the following two cohorts: (1) duration from disease onset to Expanded Disability Status Scale (EDSS) 3.0 in patients who did or did not receive oral prednisolone or biologics before reaching EDSS 3.0 and (2) duration from disease onset to EDSS 6.0 in patients who did or did not receive oral prednisolone or biologics before reaching EDSS 6.0. RESULTS: Approximately half of the untreated patients reached EDSS 3.0 and 6.0 at 10 and 46 months after disease onset, respectively. In addition, 88% and 71% of the untreated patients reached EDSS 3.0 and 6.0 within 10 years after disease onset, respectively. Disability progression, clinical relapses and attack severity were suppressed by prednisolone and biologics. CONCLUSIONS: AQP4Ab+NMOSD is a severely disabling disease. Treatment interventions using prednisolone and biologics are useful in suppressing disability progression in AQP4Ab+NMOSD.

Contributions of CSF interleukin-6 elevation to the pathogenesis of myelin oligodendrocyte glycoprotein antibody-associated disease.

BACKGROUND: Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a rare neuroinflammatory disorder characterized by acute episodes of central nervous system (CNS) demyelination. Previous studies have reported elevated interleukin (IL)-6 in cerebrospinal fluid (CSF) of MOGAD patients. OBJECTIVE: We examined if CSF IL-6 level increase is associated with clinical parameters in MOGAD. METHODS: IL-6 levels were measured using 44 CSF samples during the acute phase and 6 samples during recovery from 34 MOGAD patients, as well as 65 CSF samples from 45 aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4Ab + NMOSD), 107 samples from 76 multiple sclerosis patients, and 45 samples from neurodegenerative disease patients. Associations between IL-6 levels and clinical parameters in MOGAD were also evaluated. RESULTS: CSF IL-6 levels were significantly comparably elevated during acute-phase in MOGAD and AQP4Ab + NMOSD, but declined following the acute phase. Among MOGAD patients, CSF IL-6 level was significantly correlated with CSF cell count, greater in patients with brain lesions than spinal cord lesions, and higher in CSF than serum, suggesting that excessive IL-6 is produced predominantly in CNS. Neurological recovery was tended to be poorer in MOGAD patients with higher CSF IL-6 level. CONCLUSION: CSF IL-6 may play important roles in the pathogenesis of MOGAD, especially in CNS inflammation.

Digital Motor Biomarkers of Cerebellar Ataxia Using an RGB-Depth Camera-Based Motion Analysis System.

This study aimed to identify quantitative biomarkers of motor function for cerebellar ataxia by evaluating gait and postural control using an RGB-depth camera-based motion analysis system. In 28 patients with degenerative cerebellar ataxia and 33 age- and sex-matched healthy controls, motor tasks (short-distance walk, closed feet stance, and stepping in place) were selected from a previously reported protocol, and scanned using Kinect V2 and customized software. The Clinical Assessment Scale for the Assessment and Rating of Ataxia (SARA) was also evaluated. Compared with the normal control group, the cerebellar ataxia group had slower gait speed and shorter step lengths, increased step width, and mediolateral trunk sway in the walk test (all P < 0.001). Lateral sway increased in the stance test in the ataxia group (P < 0.001). When stepping in place, the ataxia group showed higher arrhythmicity of stepping and increased stance time (P < 0.001). In the correlation analyses, the ataxia group showed a positive correlation between the total SARA score and arrhythmicity of stepping in place (r = 0.587, P = 0.001). SARA total score (r = 0.561, P = 0.002) and gait subscore (ρ = 0.556, P = 0.002) correlated with mediolateral truncal sway during walking. These results suggest that the RGB-depth camera-based motion analyses on mediolateral truncal sway during walking and arrhythmicity of stepping in place are useful digital motor biomarkers for the assessment of cerebellar ataxia, and could be utilized in future clinical trials.

Silent progression of brain atrophy in aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder.

OBJECTIVE: To investigate longitudinal brain atrophy in patients with neuromyelitis optica spectrum disorder (NMOSD). METHODS: We investigated the longitudinal brain atrophy rate in patients with aquaporin-4 antibody-positive NMOSD (AQP4+NMOSD) and those with multiple sclerosis (MS) in a retrospective cohort study. Brain volume was calculated with statistical parametric mapping-12. RESULTS: We enrolled 36 patients with AQP4+NMOSD and 60 with MS. Patients with NMOSD were older and had a higher Kurtzke's expanded disability status scale score at baseline MRI compared with those with MS. Disease duration, annual relapse rate and intervals from the last attack and from disease-modifying drugs initiation were not significantly different between the two groups. Lower normalised lesion volume and higher normalised white matter volume were found in patients with NMOSD compared with those with MS at baseline MRI. However, the annualised atrophy rate of normalised brain volume was similar between the NMOSD (median 0.47; IQR 0.75; p=0.49) and MS (median 0.46; IQR 0.84) groups. After adjustment of age and the presence of clinical relapse, no differences of the annualised atrophy rate of normalised brain volume also were found for NMOSD and MS. Patients with AQP4+NMOSD with long cord lesion showed higher annualised atrophy rate of normalised grey matter volume compared with those without long cord lesion. CONCLUSIONS: Silent progression of brain atrophy was present in patients with AQP4+NMOSD, as shown in patients with MS, even in the clinically inactive age-matched cases. Subclinical dying back degeneration may explain the brain atrophy in patients with AQP4 +NMOSD.

Cell-based flow cytometry assay for simultaneous detection of multiple autoantibodies in a single serum sample.

Accurate serologic evaluation of autoantibodies in patients with autoimmune diseases is critical. In the present study, we established a live cell-based assay for simultaneous detection of multiple autoantibodies in a single serum sample. Autoantibody seropositivity was determined by 3-color flow cytometry using live Chinese hamster ovary cells transiently expressing a target protein of interest fused to enhanced green fluorescent protein and labeled with Alexa Fluor 647 and Hoechst 33342. As a representative example, we applied the strategy for simultaneous detection of 2 recently established biomarkers for central nervous system autoimmune inflammatory demyelinating disorders, anti-aquaporin-4 autoantibody and anti-myelin oligodendrocyte glycoprotein autoantibody, in a single serum sample. This analysis revealed the coexistence of these 2 autoantibodies. We demonstrated that this assay can simultaneously detect 3 different autoantibodies. We propose a quadrant gating strategy of flow cytometry contour plots to clearly distinguish seropositive sera from seronegative sera regardless of the extent of the background signal level or the autoantibody titer. This novel and practical method using a combination of fluorescent proteins and fluorochromes to simultaneously detect multiple autoantibodies improves the efficiency of evaluating serum samples, and therefore provides significant benefits to both the patient and the healthcare professionals performing autoantibody testing.

A case report of neuromyelitis optica spectrum disorder induced by pembrolizumab treatment for lung adenocarcinoma: a clinical and immunohistochemical study.

BACKGROUND: We report a case of neuromyelitis optica spectrum disorders (NMOSD), who developed after the pembrolizumab treatment, an immune checkpoint inhibitor, against lung adenocarcinoma. The present case is discussed with the lung adenocarcinoma specimen which was stained by aquaporin-4 (AQP4) and with literature review of NMOSD linked to immune checkpoint inhibitors. CASE PRESENTATION: A 62-year-old Japanese man presented with acute diencephalic syndrome, left optic neuritis, and myelitis 5 months after initiation of pembrolizumab treatment for lung adenocarcinoma. He was diagnosed with NMOSD based on serum anti-aquaporin-4 (AQP4) antibody positivity. Immunohistochemistry of lung biopsy samples showed AQP4 expression on CD68+ cells. This is the fifth reported case of AQP4+ NMOSD triggered by an immune checkpoint inhibitor and the first with a brain lesion. Four out of five NMOSD cases, including the present case and one case with lung metastasis, had lung cancer. CONCLUSIONS: Immune checkpoint inhibitors may trigger AQP4+ NMOSD owing to their molecular similarity to AQP4 expressed in lung and glial tissues. Prompt brain/spinal cord imaging and anti-AQP4 antibody testing may facilitate early diagnosis of immune-mediated adverse event in central nervous system associated with immune checkpoint inhibitors.

Low anti-CFL1 antibody with high anti-ACTB antibody is a poor prognostic factor in esophageal squamous cell carcinoma.

BACKGROUND: Cofilin (CFL1, actin-binding protein) and ß-actin (ACTB) are key molecules in the polymerization and depolymerization of actin microfilaments. The levels of these antibodies were analyzed, and the clinicopathological significance in patients with esophageal carcinoma were evaluated. METHODS: The levels of anti-CFL1 and anti-ACTB antibodies were analyzed in serum samples of patients with esophageal carcinoma and of healthy donors. Eighty-seven cases underwent radical surgery and the clinicopathological characteristics and prognosis was examined. RESULTS: Serum anti-CFL1 antibody (s-CFL1-Ab) levels and anti-ACTB antibody (s-ACTB-Ab) levels were significantly higher in patients with esophageal carcinoma than in healthy donors. Following the receiver operating characteristic curve analysis between healthy donors and esophageal carcinoma, the sensitivity and specificity for serum anti-CFL1 antibody (s-CFL1-Ab) were 53.3% and 68.8%. The sensitivity and specificity for serum anti-ACTB antibody (s-ACTB-Ab) were 54.9% and 67.7%, respectively. Univariate and multivariate analysis showed that s-CFL1-Ab and s-ACTB-Ab levels were not associated with sex, age, tumor depth, lymph node metastasis, or anti-p53-antibody levels. s-ACTB-Ab levels but not s-CFL1-Ab levels significantly correlated with squamous cell carcinoma antigen. Neither s-CFL1-Ab nor s-ACTB-Ab levels alone were obviously related to overall survival. However, patients with low s-CFL1-Ab levels and high s-ACTB-Ab levels exhibited significantly more unfavorable prognoses than those with high s-CFL1-Ab and low s-ACTB-Ab levels. CONCLUSIONS: Serum levels of anti-CFL1 and anti-ACTB antibodies were significantly higher in patients with esophageal carcinoma than in healthy donors. A combination of low anti-CFL1 and high anti-ACTB antibodies is a poor prognostic factor in esophageal carcinoma.

Serum anti-DIDO1, anti-CPSF2, and anti-FOXJ2 antibodies as predictive risk markers for acute ischemic stroke.

BACKGROUND: Acute ischemic stroke (AIS) is a serious cause of mortality and disability. AIS is a serious cause of mortality and disability. Early diagnosis of atherosclerosis, which is the major cause of AIS, allows therapeutic intervention before the onset, leading to prevention of AIS. METHODS: Serological identification by cDNA expression cDNA libraries and the protein array method were used for the screening of antigens recognized by serum IgG antibodies in patients with atherosclerosis. Recombinant proteins or synthetic peptides derived from candidate antigens were used as antigens to compare serum IgG levels between healthy donors (HDs) and patients with atherosclerosis-related disease using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay. RESULTS: The first screening using the protein array method identified death-inducer obliterator 1 (DIDO1), forkhead box J2 (FOXJ2), and cleavage and polyadenylation specificity factor (CPSF2) as the target antigens of serum IgG antibodies in patients with AIS. Then, we prepared various antigens including glutathione S-transferase-fused DIDO1 protein as well as peptides of the amino acids 297-311 of DIDO1, 426-440 of FOXJ2, and 607-621 of CPSF2 to examine serum antibody levels. Compared with HDs, a significant increase in antibody levels of the DIDO1 protein and peptide in patients with AIS, transient ischemic attack (TIA), and chronic kidney disease (CKD) but not in those with acute myocardial infarction and diabetes mellitus (DM). Serum anti-FOXJ2 antibody levels were elevated in most patients with atherosclerosis-related diseases, whereas serum anti-CPSF2 antibody levels were associated with AIS, TIA, and DM. Receiver operating characteristic curves showed that serum DIDO1 antibody levels were highly associated with CKD, and correlation analysis revealed that serum anti-FOXJ2 antibody levels were associated with hypertension. A prospective case-control study on ischemic stroke verified that the serum antibody levels of the DIDO1 protein and DIDO1, FOXJ2, and CPSF2 peptides showed significantly higher odds ratios with a risk of AIS in patients with the highest quartile than in those with the lowest quartile, indicating that these antibody markers are useful as risk factors for AIS. CONCLUSIONS: Serum antibody levels of DIDO1, FOXJ2, and CPSF2 are useful in predicting the onset of atherosclerosis-related AIS caused by kidney failure, hypertension, and DM, respectively.

Direct writing of silicon nanostructures using liquid-phase electron beam induced deposition of hydrosilanes.

Solid Si (wafer) and gaseous Si (silane) are generally used as starting materials for fabricating Si devices. In this study, a liquid precursor (liquid-phase hydrosilane) for semiconducting Si, called liquid Si (liq-Si), was synthesized to establish a liquid pathway for fabricating Si. Although the liquid-to-solid Si conversion can be induced by heating at 400 °C, conversion without heating was realized herein by electron-beam (EB) irradiation. This study is the first to irradiate liq-Si with EB. Size-controllable Si nanodots, with diameters of the order of 100 nm, were directly deposited at any point by liquid-phase electron-beam-induced deposition (LP-EBID) with a beam diameter of 50 nm. This approach yielded less-contaminated deposits at the detection limit of energy-dispersive x-ray spectroscopy, as opposed to typical EBID, wherein carbon impurities up to 90% are found. The processing resolution of LP-EBID is potentially 1 nm or less. Therefore, this non-heating deposition technique realizes the direct writing of Si nanostructures and would be a powerful tool for Si nanofabrication.

Impact of visceral fat on the prognosis of coronavirus disease 2019: an observational cohort study.

BACKGROUND: Clarification of the risk factors for coronavirus disease 2019 (COVID-19) severity is strongly warranted for global health. Recent studies have indicated that elevated body mass index (BMI) is associated with unfavorable progression of COVID-19. This is assumed to be due to excessive deposition of visceral adipose tissue (VAT); however, the evidence investigating the association between intra-abdominal fat and COVID-19 prognosis is sparse. We therefore investigated whether measuring the amount of intra-abdominal fat is useful to predict the prognosis of COVID-19. METHODS: The present study enrolled 53 consecutive cases of COVID-19 patients aged ≥ 20 years with chest computed tomography (CT) scans. The VAT area, total adipose tissue (TAT) area, and VAT/TAT ratio were estimated using axial CT images at the level of the upper pole of the right kidney. Severe COVID-19 was defined as death or acute respiratory failure demanding oxygen at ≥ 6 L per minute, a high-flow nasal cannula, or mechanical ventilation. The association of VAT/TAT with the incidence of progression to a severe state was estimated as a hazard ratio (HR) using Cox regression analysis. To compare the prediction ability for COVID-19 disease progression between BMI and VAT/TAT, the area under the receiver operating characteristic curve (AUC) of each was assessed. RESULTS: A total of 15 cases (28.3% of the whole study subjects) progressed to severe stages. The incidence of developing severe COVID-19 increased significantly with VAT/TAT (HR per 1% increase = 1.040 (95% CI 1.008-1.074), P = 0.01). After adjustment for potential confounders, the positive association of VAT/TAT with COVID-19 aggravation remained significant (multivariable-adjusted HR = 1.055 (95% CI 1.000-1.112) per 1% increase, P = 0.049). The predictive ability of VAT/TAT for COVID-19 becoming severe was significantly better than that of BMI (AUC of 0.73 for VAT/TAT and 0.50 for BMI; P = 0.0495 for the difference). CONCLUSIONS: A higher ratio of VAT/TAT was an independent risk factor for disease progression among COVID-19 patients. VAT/TAT was superior to BMI in predicting COVID-19 morbidity. COVID-19 patients with high VAT/TAT levels should be carefully observed as high-risk individuals for morbidity and mortality.

Dementia and Parkinson-like syndrome with basal ganglia lesion in neuromyelitis optica spectrum disorders.

Brain lesions in neuromyelitis optica spectrum disorders (NMOSD) are generally located at sites of high anti-aquaporin 4 (AQP4) expression. Clinical features of NMOSD associated with basal ganglia damage in sites not enriched with AQP4 remain unknown. Here we describe the case of an 82-year-old woman who developed dementia and bradykinesia for 5 weeks. Brain magnetic resonance imaging revealed obvious basal ganglia abnormalities. Test for serum anti-AQP4 antibody was positive, and she was diagnosed with NMOSD. Our case showed that NMOSD associated with dementia and/or Parkinson-like syndrome with basal ganglia lesions could be another clinical presentation in NMOSD.

Cognitive Impairment in Multiple System Atrophy Is Related to White Matter Damage Detected by the T1-Weighted/T2-Weighted Ratio.

INTRODUCTION: This study aimed to use a novel MRI contrast, the standardized T1-weighted/T2-weighted (sT1w/T2w) ratio, to assess damage of the white matter and gray matter in multiple system atrophy (MSA). Furthermore, this study investigated whether the sT1w/T2w ratio was associated with cognitive impairment in MSA. METHODS: The white matter and gray matter sT1w/T2w ratio of 37 MSA patients and 19 healthy controls were measured. Correlation analyses were used to evaluate the relationship between sT1w/T2w ratio values and clinical variables, and a multivariate analysis was used to identify independent factors associated with cognitive impairment in MSA. RESULTS: MSA patients showed a higher white matter sT1w/T2w ratio value than controls (p < 0.001), and the white matter sT1w/T2w ratio value was significantly correlated with the International Cooperative Ataxia Rating Scale score (r = 0.377, p = 0.021) and the Addenbrooke's cognitive examination III score (r = -0.438, p = 0.007). Cognitively impaired MSA patients had a significantly higher white matter sT1w/T2w ratio value than cognitively preserved MSA patients (p = 0.010), and the multiple logistic regression analysis revealed that the median white matter sT1w/T2w ratio value was independently associated with cognitive impairment in MSA. CONCLUSION: The sT1w/T2w ratio is sensitive to degenerative changes in the white matter that is associated with cognitive ability in MSA patients.

Serum anti-LRPAP1 is a common biomarker for digestive organ cancers and atherosclerotic diseases.

Some cancers are related to atherosclerotic diseases; therefore, these two types of disease may share some antibody biomarkers in common. To investigate this, a first screening of sera was performed from patients with esophageal squamous cell carcinoma (ESCC) or acute ischemic stroke (AIS) for serological identification of antigens using recombinant cDNA expression cloning (SEREX). The amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) method, which incorporates glutathione donor beads and anti-human IgG acceptor beads, was used to evaluate serum antibody levels. SEREX screening identified low-density lipoprotein receptor-related protein-associated protein 1 (LRPAP1) as a target antigen of serum IgG antibodies in the sera of patients with ESCC or AIS. Antigens, including recombinant glutathione S-transferase-fused LRPAP1 protein, were prepared to examine serum antibody levels. AlphaLISA revealed significantly higher antibody levels against the LRPAP1 protein in patients with solid cancers such as ESCC and colorectal carcinoma and some atherosclerosis-related diseases such as AIS and diabetes mellitus compared with healthy donors. Correlation analysis revealed that the elevated serum antibody levels against LRPAP1 were associated with smoking, a well-known risk factor for both cancer and atherosclerosis. Serum LRPAP1 antibody is therefore a common marker for the early diagnosis of some cancers and atherosclerotic diseases and may reflect diseases caused by habitual smoking.

Peripheral blood helper T cell profiles and their clinical relevance in MOG-IgG-associated and AQP4-IgG-associated disorders and MS.

OBJECTIVE: To investigate the immunological characteristics and their clinical relevance in anti-myelin oligodendrocyte glycoprotein (MOG)-IgG-associated and anti-aquaporin-4 (AQP4)-IgG-associated disorders (MOGAD and AQPAD) and multiple sclerosis (MS). METHODS: We measured peripheral blood helper T cell subsets (Th1, Th2, Th17 and regulatory T cell (Treg)) in patients with MOGAD (n=26), AQPAD (n=32) and MS (n=28) in the attack and remission phases by flow cytometry with intracellular cytokine staining. We also studied their correlation with clinical parameters. Ten normal subjects served as healthy controls. RESULTS: In all the three disorders, Th17 significantly increased at attack, and downregulated in the remission phases, although still elevated compare with healthy controls. MOGAD and AQPAD patients shared the common T cell profiles, while the extent of Th17 shift was more prominent in AQPAD. Patients with MS showed decreased Th2 than ones with MOGAD and AQPAD at attack. In terms of clinical correlation, MS patients showed that higher Th1 and Th17 proportion was associated with more frequent relapse and more severe clinical disability, whereas in MOGAD, higher Treg was associated with milder clinical severity. In AQPAD, no obvious correlation of Th profiles with clinical manifestation was found. CONCLUSIONS: The present study first investigated intracellular cytokine levels among MOGAD, AQPAD and MS. The different patterns and extent of helper T cell profiles could reflect the pathogenesis of each disorders, and may affect disease severity and activity.

Anti-MOG antibody-associated disorders: differences in clinical profiles and prognosis in Japan and Germany.

BACKGROUND: Neurological disorders with IgG antibodies against myelin-oligodendrocyte glycoprotein (MOG-IgG) have been increasingly recognised as a new type of neuroinflammatory disorder. OBJECTIVE: The study aimed to identify regional and ethnic differences in clinical profiles of MOG-IgG-associated disorders between East Asian (Japanese) and Caucasian (German) patients. METHODS: Demographic, clinical and therapeutic data from 68 MOG-IgG-positive adults were collected (Japanese, n=44; German, n=24). RESULTS: Age and sex were similar between cohorts, with optic neuritis occurring most frequently at onset (Japanese: 61%; German: 58%). However, Japanese patients had a lower annualised relapse rate (0.4 vs 0.8, p=0.019; no relapse, 64% vs 25%, p=0.002) and lower Expanded Disability Status Scale score at the last visit (1.0 vs 2.0; p=0.008), despite similar follow-up periods (mean, 73.9 months vs 73.4 months), than those of German patients, respectively. Cerebral syndromes were more common (27% vs 4%; p=0.021) and myelitis less common (21% vs 50%; p=0.012) in Japanese than in German patients, respectively. Japanese patients were more commonly treated with long-term corticosteroids (73%), whereas German patients were more commonly treated with rituximab or other immunosuppressants (63%). CONCLUSIONS: Among patients with MOG-IgG, Japanese tended to have a monophasic milder disease, whereas the majority of German patients had a relapsing course and more frequent myelitis, findings compatible with neuromyelitis optica spectrum disorder. Although the attack-prevention treatment regimens were considerably different, genetic and environmental factors may be important to determine clinical phenotypes and disease activity.

Roles of afadin in functional differentiations of hippocampal mossy fiber synapse.

A hippocampal mossy fiber synapse has a complex structure and is implicated in learning and memory. In this synapse, the mossy fiber boutons attach to the dendritic shaft by puncta adherentia junctions and wrap around a multiply-branched spine, forming synaptic junctions. We have recently shown using transmission electron microscopy, immunoelectron microscopy and serial block face-scanning electron microscopy that atypical puncta adherentia junctions are formed in the afadin-deficient mossy fiber synapse and that the complexity of postsynaptic spines and mossy fiber boutons, the number of spine heads, the area of postsynaptic densities and the density of synaptic vesicles docked to active zones are decreased in the afadin-deficient synapse. We investigated here the roles of afadin in the functional differentiations of the mossy fiber synapse using the afadin-deficient mice. The electrophysiological studies showed that both the release probability of glutamate and the postsynaptic responsiveness to glutamate were markedly reduced, but not completely lost, in the afadin-deficient mossy fiber synapse, whereas neither long-term potentiation nor long-term depression was affected. These results indicate that afadin plays roles in the functional differentiations of the presynapse and the postsynapse of the hippocampal mossy fiber synapse.

Intravenous immunoglobulin for maintenance treatment of multifocal motor neuropathy: A multi-center, open-label, 52-week phase 3 trial.

Intravenous immunoglobulin (IVIg) therapy is currently the only established treatment in patients with multifocal motor neuropathy (MMN), and many patients have an IVIg-dependent fluctuation. We aimed to investigate the efficacy and safety of every 3 week IVIg (1.0 g/kg) for 52 weeks. This study was an open-label phase 3 clinical trial, enrolling 13 MMN patients. After an induction IVIg therapy (0.4 g/kg/d for 5 consecutive days), maintenance dose (1.0 g/kg) was given every 3 weeks for 52 weeks. The major outcome measures were the Medical Research Council (MRC) sum score and hand-grip strength at week 52. This trial is registered with ClinicalTrials.gov, number NCT01827072. At week 52, 11 of the 13 patients completed the study, and all 11 had a sustained improvement. The mean (SD) MRC sum score was 85.6 (8.7) at the baseline, and 90.6 (12.8) at week 52. The mean grip strength was 39.2 (30.0) kPa at the baseline and 45.2 (32.8) kPa at week 52. Two patients dropped out because of adverse event (dysphagia) and decision of an investigator, respectively. Three patients developed coronary spasm, dysphagia, or inguinal herniation, reported as the serious adverse events, but considered not related with the study drug. The other adverse effects were mild and resolved by the end of the study period. Our results show that maintenance treatment with 1.0 g/kg IVIg every 3 week is safe and efficacious for MMN patients up to 52 weeks. Further studies are required to investigate optimal dose and duration of maintenance IVIg for MMN.

Regulatory role of the cell adhesion molecule nectin-1 in GABAergic inhibitory synaptic transmission in the CA3 region of mouse hippocampus.

Proper operation of a neural circuit relies on both excitatory and inhibitory synapses. We previously showed that cell adhesion molecules nectin-1 and nectin-3 are localized at puncta adherentia junctions of the hippocampal mossy fiber glutamatergic excitatory synapses and that they do not regulate the excitatory synaptic transmission onto the CA3 pyramidal cells. We studied here the roles of these nectins in the GABAergic inhibitory synaptic transmission onto the CA3 pyramidal cells using nectin-1-deficient and nectin-3-deficient cultured mouse hippocampal slices. In these mutant slices, the amplitudes and frequencies of miniature excitatory postsynaptic currents were indistinguishable from those in the control slices. In the nectin-1-deficient slices, but not in the nectin-3-deficient slices, however, the amplitude of miniature inhibitory postsynaptic currents (mIPSCs) was larger than that in the control slices, although the frequency of the mIPSCs was not different between these two groups of slices. In the dissociated culture of hippocampal neurons from the nectin-1-deficient mice, the amplitude and frequency of mIPSCs were indistinguishable from those in the control neurons. Nectin-1 was not localized at or near the GABAergic inhibitory synapses. These results indicate that nectin-1 regulates the neuronal activities in the CA3 region of the hippocampus by suppressing the GABAergic inhibitory synaptic transmission.

Intravenous immunoglobulin for maintenance treatment of chronic inflammatory demyelinating polyneuropathy: a multicentre, open-label, 52-week phase III trial.

OBJECTIVE: Short-term efficacy of induction therapy with intravenous immunoglobulin (Ig) in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) is well established. However, data of previous studies on maintenance therapy were limited up to 24-week treatment period. We aimed to investigate the efficacy and safety of longer-term intravenous Ig therapy for 52 weeks. METHODS: This study was an open-label phase 3 clinical trial conducted in 49 Japanese tertiary centres. 49 patients with CIDP who fulfilled diagnostic criteria were included. After an induction intravenous Ig therapy (0.4 g/kg/day for five consecutive days), maintenance dose intravenous Ig (1.0 g/kg) was given every 3 weeks for up to 52 weeks. The primary outcome measures were the responder rate at week 28 and relapse rate at week 52. The response and relapse were defined with the adjusted Inflammatory Neuropathy Cause and Treatment scale. RESULTS: At week 28, the responder rate was 77.6% (38/49 patients; 95% CI 63% to 88%), and the 38 responders continued the maintenance therapy. At week 52, 4 of the 38 (10.5%) had a relapse (95% CI 3% to 25%). During 52 weeks, 34 (69.4%) of the 49 enrolled patients had a maintained improvement. Adverse events were reported in 94% of the patients; two patients (66-year-old and 76-year-old men with hypertension or diabetes) developed cerebral infarction (lacunar infarct with good recovery), and the other adverse effects were mild and resolved by the end of the study period. CONCLUSIONS: Maintenance treatment with 1.0 g/kg intravenous Ig every 3 weeks is an efficacious therapy for patients with CIDP, and approximately 70% of them had a sustained remission for 52 weeks. Thrombotic complications should be carefully monitored, particularly in elderly patients with vascular risk factors. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov (NCT01824251).