Clinical features and management of coexisting anti-N-methyl-D-aspartate receptor encephalitis and myelin oligodendrocyte glycoprotein antibody-associated encephalomyelitis: a case report and review of the literature

BACKGROUND

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is an autoimmune encephalitis caused by antibodies targeting the GluN1 subunit of NMDA receptors. Myelin oligodendrocyte glycoprotein (MOG) antibody disorders are now widely accepted as peculiar neuroimmunological diseases with specific clinical and pathological features. Some rare cases of overlapping anti-NMDA receptor encephalitis and MOG antibody-associated diseases have been reported, presenting complex clinical symptoms that make the disease more difficult to recognize.

METHOD

In accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, the terms "NMDAR" and "MOG," "NMDAR" and "demyelination," and "MOG" and "encephalitis" were searched in PubMed. Clinical cases with dual-positive anti-NMDA cerebrospinal fluid receptors and MOG serum antibodies during the disease course were included in this study.

RESULTS

A total of 25 patients were analyzed in this study. The age at onset ranged from 3 to 54 years. The median number of relapses was 2.8. Administration of intravenous methylprednisolone and immunoglobulin was the most widely used treatment strategy (19/25 patients). Second-line treatments such as administration of mycophenolate mofetil, rituximab, interferon-β, azathioprine, cyclophosphamide, and temozolomide were also reported, followed by good outcomes.

CONCLUSIONS

The rates of coexisting anti-NMDA receptor encephalitis and MOG antibody-associated encephalomyelitis may be underestimated. Clinical symptoms such as seizures and cognitive decline accompanied by atypical central nervous system demyelination serve as warning signs of possible coexisting anti-NMDA receptor encephalitis and MOG antibody-associated encephalomyelitis. These patients could achieve good outcomes under proper immunotherapies.

Circulating regulatory B cell subsets in patients with neuromyelitis optica spectrum disorders

This study analyzed the populations of three different subsets of regulatory B cells (Bregs) in the peripheral blood mononuclear cells (PBMCs) of patients with neuromyelitis optica spectrum disorders (NMOSDs) and explored the relationship between the changes in these subsets of Bregs and the severity of NMOSD. A total of 22 patients with relapsed NMOSDs before treatment were recruited in our study, along with 20 age and gender-matched healthy controls, from May 2015 to March 2016. The percentages and numbers for three different subsets of Bregs including the CD19+CD24hiCD38hi, CD19+CD24hiCD27+, and CD19+CD5+CD1dhi populations were evaluated in parallel by flow cytometry. Afterwards, correlations between the change of three different subsets of Bregs and disease severity were analyzed. We found significantly lower percentages of CD19+CD24hiCD38hi and CD19+CD5+CD1dhi Bregs in NMOSDs patients than in healthy individuals. In contrast, the CD19+CD24hiCD27+ Bregs population was significantly higher in NMOSDs patients than in healthy individuals. However, the three different Bregs subsets showed no significant correlation with expanded disability status scale (EDSS) or annualized relapse rate (ARR). Our findings suggest that the subsets of Bregs may play complex roles in the pathogenesis of NMOSDs and are not correlated with clinical disease severity. Further insights into the potential role of subsets of Bregs could increase our basic knowledge of NMOSDs pathogenesis.

Disulfide and Fully Reduced HMGB1 Induce Different Macrophage Polarization and Migration Patterns

Macrophage plasticity enables cells to obtain different functions over a broad proinflammatory and repairing spectrum. In different conditions, macrophages can be induced by high-mobility group box 1 (HMGB1), a nuclear DNA-binding protein that activates innate immunity, to polarize towards a pro- (M1) or anti-inflammatory (M2) phenotype. In this study, we investigated the phenotypes of murine bone-marrow-derived macrophages (BMDMs) induced by different HMGB1 redox isoforms in depth. Our results demonstrate that disulfide HMGB1 (dsHMGB1) induces a unique macrophage phenotype that secretes pro-inflammatory cytokines, rather than inducing metabolic changes leading to nitric oxide production. Fully reduced HMGB1 (frHMGB1) did not induce macrophage polarization. The migrating function of BMDMs was measured by scratch assay after the stimulation with dsHMGB1 and frHMGB1. Both dsHMGB1 and frHMGB1 induced cell migration. We found that dsHMGB1 mediates cytokine secretion and cellular motility, mainly through toll-like receptor 4 (TLR4). Importantly, our data shows that dsHMGB1 and frHMGB1 induce distinct BMDM polarization phenotypes, and that dsHMGB1 induces a unique phenotype differing from the classical proinflammatory macrophage phenotype.

THAN: task-driven hierarchical attention network for the diagnosis of mild cognitive impairment and Alzheimer's disease

BACKGROUND

To assist doctors to diagnose mild cognitive impairment (MCI) and Alzheimer's disease (AD) early and accurately, convolutional neural networks based on structural magnetic resonance imaging (sMRI) images have been developed and shown excellent performance. However, they are still limited in their capacity in extracting discriminative features because of large sMRI image volumes yet small lesion regions and the small number of sMRI images.

METHODS

We proposed a task-driven hierarchical attention network (THAN) taking advantage of the merits of patch-based and attention-based convolutional neural networks for MCI and AD diagnosis. THAN consists of an information sub-network and a hierarchical attention sub-network. In the information sub-network, an information map extractor, a patch-assistant module, and a mutual-boosting loss function are designed to generate a task-driven information map, which automatically highlights disease-related regions and their importance for final classification. In the hierarchical attention sub-network, a visual attention module and a semantic attention module are devised based on the information map to extract discriminative features for disease diagnosis.

RESULTS

Extensive experiments were conducted for four classification tasks: MCI versus (vs.) normal controls (NC), AD vs. NC, AD vs. MCI, and AD vs. MCI vs. NC. Results demonstrated that THAN attained the accuracy of 81.6% for MCI vs. NC, 93.5% for AD vs. NC, 80.8% for AD vs. MCI, and 62.9% for AD vs. MCI vs. NC. It outperformed advanced attention-based and patch-based methods. Moreover, information maps generated by the information sub-network could highlight the potential biomarkers of MCI and AD, such as the hippocampus and ventricles. Furthermore, when the visual and semantic attention modules were combined, the performance of the four tasks was highly improved.

CONCLUSIONS

The information sub-network can automatically highlight the disease-related regions. The hierarchical attention sub-network can extract discriminative visual and semantic features. Through the two sub-networks, THAN fully exploits the visual and semantic features of disease-related regions and meanwhile considers global features of sMRI images, which finally facilitate the diagnosis of MCI and AD.

Elevated serum interleukin-39 levels in patients with neuromyelitis optica spectrum disorders correlated with disease severity

AIMS

Neuromyelitis optica spectrum disorders (NMOSD) is an inflammatory demyelinating autoimmune disorder in the central nervous system (CNS), which is mainly mediated by aquaporin 4 antibodies (AQP4-Ab). Interleukin (IL)-39 is a new pro-inflammatory cytokine which belongs to the IL-12 cytokine family. However, the role of IL-39 in patients with NMOSD is not completely understood. Therefore, the aim of this study is to explore the possible implication of IL-39 in the pathogenesis of NMOSD.

METHODS

In this study, 50 patients with NMOSD, 20 patients with relapsing-remitting multiple sclerosis (RRMS), 30 patients with non-inflammatory neurological disorders (NND) and 78 healthy controls (HCs) were recruited. The levels of serum IL-39 were measured using the enzyme-linked immunosorbent assay (ELISA).

RESULTS

Our study showed serum IL-39 levels in patients with NMOSD were significantly higher than that in RRMS patients, NND patients and HCs, and positively correlated with Expanded Disability Status Scale (EDSS) score.

CONCLUSION

These findings suggested that IL-39 may play a pro-inflammatory role in the pathogenesis of NMOSD and correlate with disease severity.

Evolution and major changes of the diagnosis and treatment protocol for COVID-19 patients in China 2020-2023

Since the identification of the first case of pneumonia of unknown cause in 2019, the COVID-19 pandemic has spread the globe for over 3 years. As the most populous country in the world, China's disease prevention policies and response plans concern the health of the country's 1.4 billion people and beyond. During the course of the pandemic, scientific research has been accumulated and given evidence-based support to the official guidance of COVID-19 management. The National Health Commission of China have compiled, published, and updated a total of 10 versions of the "Diagnosis and Treatment Protocol for COVID-19 Patients" to better inform clinical practitioners and staff to effectively screen, diagnose, manage, treat, and care for cases of severe acute respiratory syndrome coronavirus 2 infection. This paper compares and summarizes each version of the protocol in terms of etiology and epidemiology, clinical manifestation and diagnosis, treatment and nursing, disease control and management, presenting detailed changes, additions, deletions, and refinement of the protocols.

A Novel Missense Mutation of the CSF1R Gene Causes Incurable CSF1R-Related Leukoencephalopathy: Case Report and Review of Literature

CSF1R-related leukoencephalopathy, mainly caused by the mutation of the colony stimulating factor 1 receptor (CSF1R) gene on chromosome 5, is an underestimated neurological disease typically presenting as early-onset cognitive decline and personality changes. Currently, there is no specific treatment for CSF1R-related leukoencephalopathy. Most clinicians failed to recognize this disease during an early disease stage, leading to a high rate of misdiagnosis. Although rare, an increasing amount of CSF1R-related leukoencephalopathy cases have been reported recently. In this study, we first report a 35-year-old woman with CSF1R-related leukoencephalopathy carrying a novel missense mutation c.2463G >C (p.W821C) of CSF1R. An extensive literature research was performed in order to better understand the broader genetic and clinical characteristics of CSF1R-related leukoencephalopathy. A total of 147 patients with CSF1R-related leukoencephalopathy confirmed either by the genetic test or brain biopsy were identified. Among them, 49 patients were sporadic, and the rest of individuals had a family history originating from 46 different families. Our study indicated that the average age of CSF1R-related leukoencephalopathy onset was 41.4 years. Typical clinical symptoms of CSF1R-related leukoencephalopathy include cognitive decline, movement disorders, behavior changes and mental disorders. Genetic studies have reported 93 missense mutations, 13 splicing mutations, 6 deletion/insertion mutations, 1 code shift mutation and 1 nonsense mutation of the CSF1R gene in patients with CSF1R-related leukoencephalopathy. Early genetic detection and brain biopsy would be helpful for a confirmed diagnosis, and more translational studies are needed to combat this devastating disease.

Absence of microglia or presence of peripherally-derived macrophages does not affect tau pathology in young or old hTau mice

Microglia are implicated in the pathophysiology of several neurodegenerative disorders, including Alzheimer's disease. While the role of microglia and peripheral macrophages in regulating amyloid beta pathology has been well characterized, the impact of these distinct cell subsets on tau pathology remains poorly understood. We and others have recently demonstrated that monocytes can engraft the brain and give rise to long-lived parenchymal macrophages, even under nonpathological conditions. We undertook the current study to investigate the regulation of tau pathology by microglia and peripheral macrophages using hTau transgenic mice, which do not exhibit microglial activation/pathology or macrophage engraftment. To assess the direct impact of microglia on tau pathology we developed a protocol for long-term microglial depletion in Cx3cr1CreER R26DTA mice and crossed them with hTau mice. We then depleted microglia up to 3 months in both young and old mice, but no net change in forebrain soluble oligomeric tau or total or phosphorylated levels of aggregated tau was recorded. To investigate the consequence of peripherally-derived parenchymal macrophages on tau aggregation we partially repopulated the hTau microglial pool with peripheral macrophages, but this also did not affect levels of tau oligomers or insoluble aggregates. Our study questions the direct involvement of microglia or peripheral macrophages in the development of tau pathology in the hTau model.

PD-1/PD-L1 Axis as a Potential Therapeutic Target for Multiple Sclerosis: A T Cell Perspective

The programmed cell death protein-1/programmed death ligand-1 (PD-1/PD-L1) axis is a widely studied immune checkpoint that modulates signaling pathways related to T cell activation. The use of PD-1/PD-L1 inhibitors is a promising immune therapy strategy for cancer patients. However, individuals treated with PD-1/PD-L1 inhibitors may develop immune-related adverse events due to excessive immune reactions. Multiple sclerosis (MS) is a chronic demyelinating and neurodegenerative disease of the central nervous system. T cells and the PD-1/PD-L1 axis play vital roles in the pathogenesis of MS. A better understanding of the complex relationship between the PD-1/PD-L1 axis and T cells may extend our knowledge of the molecular mechanisms and therapeutic approaches for MS. In this review, we summarize the most recent findings regarding the role of the PD-1/PD-L1 axis in MS and discuss the potential therapeutic strategies to modulate the expression of PD-1/PD-L1 in MS.

An overlooked subset of Cx3cr1wt/wt microglia in the Cx3cr1CreER-Eyfp/wt mouse has a repopulation advantage over Cx3cr1CreER-Eyfp/wt microglia following microglial depletion

BACKGROUND

Fluorescent reporter labeling and promoter-driven Cre-recombinant technologies have facilitated cellular investigations of physiological and pathological processes, including the widespread use of the Cx3cr1CreER-Eyfp/wt mouse strain for studies of microglia.

METHODS

Immunohistochemistry, Flow Cytometry, RNA sequencing and whole-genome sequencing were used to identify the subpopulation of microglia in Cx3cr1CreER-Eyfp/wt mouse brains. Genetically mediated microglia depletion using Cx3cr1CreER-Eyfp/wtRosa26DTA/wt mice and CSF1 receptor inhibitor PLX3397 were used to deplete microglia. Primary microglia proliferation and migration assay were used for in vitro studies.

RESULTS

We unexpectedly identified a subpopulation of microglia devoid of genetic modification, exhibiting higher Cx3cr1 and CX3CR1 expression than Cx3cr1CreER-Eyfp/wtCre+Eyfp+ microglia in Cx3cr1CreER-Eyfp/wt mouse brains, thus termed Cx3cr1highCre-Eyfp- microglia. This subpopulation constituted less than 1% of all microglia under homeostatic conditions, but after Cre-driven DTA-mediated microglial depletion, Cx3cr1highCre-Eyfp- microglia escaped depletion and proliferated extensively, eventually occupying one-third of the total microglial pool. We further demonstrated that the Cx3cr1highCre-Eyfp- microglia had lost their genetic heterozygosity and become homozygous for wild-type Cx3cr1. Therefore, Cx3cr1highCre-Eyfp- microglia are Cx3cr1wt/wtCre-Eyfp-. Finally, we demonstrated that CX3CL1-CX3CR1 signaling regulates microglial repopulation both in vivo and in vitro.

CONCLUSIONS

Our results raise a cautionary note regarding the use of Cx3cr1CreER-Eyfp/wt mouse strains, particularly when interpreting the results of fate mapping, and microglial depletion and repopulation studies.

Effects of Follicular Helper T Cells and Inflammatory Cytokines on Myasthenia Gravis

BACKGROUND

Myasthenia gravis (MG) is an autoimmune disorder mediated by antibodies against the acetylcholine receptors (AChR) of the skeletal muscles. An imbalance in various T helper (Th) cells, including Th1, Th2, Th17, Th22 and follicular helper T (TFH) cells, has been found associated with immunological disturbances.

OBJECTIVE

In this study, we aim to investigate the role of the Th cells in peripheral blood of MG patients.

MATERIALS AND METHODS

A total of 33 MG patients and 34 age matched controls were enrolled in this study. Peripheral blood mononuclear cells (PBMCs) were isolated using Ficoll-Paque density gradient centrifugation assay. The proportion of TFH cells in PBMC were analyzed using flow-cytometry assay by determining the levels of cellular markers CD4, CXCR5, CD45RO, CD45RA and ICOS and PD-1. The levels of IFN-γ, IL-4, IL-17 and IL-21 in serum were analyzed by Cytometric Bead Array. The serum IL-22 level was analyzed by ELISA.

RESULTS

The frequency of TFH cells in PBMCs was higher than those in healthy subjects and correlated to the severity of MG patients. The levels of pro-inflammatory cytokines IFN-γ, IL-17 and IL-21 were elevated in the serum of MG patients, while there were no significant differences regarding the levels of IL-4 and IL-22 between MG patients and control subjects.

CONCLUSION

Our findings suggest that Th cells and their cytokines balance of MG patients are involved in the clinical condition or severity of MG disease.

Role of N6-methyladenosine methylation in glioma: recent insights and future directions

Glioma is the most pervasive intracranial tumor in the central nervous system (CNS), with glioblastoma (GBM) being the most malignant type having a highly heterogeneous cancer cell population. There is a significantly high mortality rate in GBM patients. Molecular biomarkers related to GBM malignancy may have prognostic values in predicting survival outcomes and therapeutic responses, especially in patients with high-grade gliomas. In particular, N6-methyladenine (m6A) mRNA modification is the most abundant form of post-transcriptional RNA modification in mammals and is involved in regulating mRNA translation and degradation. Cumulative findings indicate that m6A methylation plays a crucial part in neurogenesis and glioma pathogenesis. In this review, we summarize recent advances regarding the functional significance of m6A modification and its regulatory factors in glioma occurrence and progression. Significant advancement of m6A methylation-associated regulators as potential therapeutic targets is also discussed.

Sex-Specific Effects of Microglia-Like Cell Engraftment during Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is a chronic neuroinflammatory disorder of the central nervous system (CNS) that usually presents in young adults and predominantly in females. Microglia, a major resident immune cell in the CNS, are critical players in both CNS homeostasis and disease. We have previously demonstrated that microglia can be efficiently depleted by the administration of tamoxifen in Cx3cr1CreER/+Rosa26DTA/+ mice, with ensuing repopulation deriving from both the proliferation of residual CNS resident microglia and the engraftment of peripheral monocyte-derived microglia-like cells. In this study, tamoxifen was administered to Cx3cr1CreER/+Rosa26DTA/+ and Cx3cr1CreER/+ female and male mice. Experimental autoimmune encephalomyelitis (EAE), a widely used animal model of MS, was induced by active immunization with myelin oligodendrocyte glycoprotein (MOG) one month after tamoxifen injections in Cx3cr1CreER/+Rosa26DTA/+ mice and Cx3cr1CreER/+ mice, a time point when the CNS niche was colonized by microglia derived from both CNS microglia and peripherally-derived macrophages. We demonstrate that engraftment of microglia-like cells following microglial depletion exacerbated EAE in Cx3cr1CreER/+Rosa26DTA/+ female mice as assessed by clinical symptoms and the expression of CNS inflammatory factors, but these findings were not evident in male mice. Higher major histocompatibility complex class II expression and cytokine production in the female CNS contributed to the sex-dependent EAE severity in mice following engraftment of microglia-like cells. An underestimated yet marked sex-dependent microglial activation pattern may exist in the injured CNS during EAE.

Autoimmune glial fibrillary acidic protein astrocytopathy with lesions distributed predominantly in the entire spinal cord

Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy has been considered a novel central nervous system autoimmune disease characterized by relapse and responsiveness to corticosteroid with a specific GFAP-Immunoglobulin G (IgG) being noted in cerebrospinal fluid. We report the case of a 21-year-old girl presenting with dysuria and weariness, who subsequently developed blurry vision, slight dysphagia, slurred speech, and sensory abnormality. GFAP-IgG was detected in her cerebrospinal fluid. Magnetic resonance imaging using both T2-weighted and contrast-enhanced T1-weighted images revealed a rare finding of lesions distributed mainly in the entire spinal cord rather than typical brain lesions. After treating with corticosteroids, her clinical symptoms were alleviated, and the spinal cord lesion enhancement was reduced. Our observations extend the clinical spectrum of autoimmune GFAP astrocytopathy. We suggest that rare distributed lesions in the entire spinal cord in patients with autoimmune GFAP astrocytopathy cannot be ignored by neurologists. The identification of potential atypical lesions broadens the understanding of autoimmune GFAP astrocytopathy.

Blood Brain Barrier Permeability Could Be a Biomarker to Predict Severity of Neuromyelitis Optica Spectrum Disorders: A Retrospective Analysis

Background: Blood-brain barrier (BBB) pathology exists in neuromyelitis optica spectrum disorders (NMOSD). However, the clinical use of BBB permeability, such as predicting disease severity of NMOSD, has rarely been studied in a large cohort of patients. Objectives: The current study explored the association between BBB permeability and clinical parameters in order to assess if BBB permeability could be a biomarker to predict disease severity and clinical characteristics of NMOSD. Methods: Among 69 enrolled NMOSD patients, 47 with albumin index over 5 × 10-3 were assigned to the increased BBB permeability group, and the remaining 22 were to the normal BBB permeability group. Disease severity was assessed using the Expanded Disability Status Scale (EDSS). Results: Patients in the increased BBB permeability group had significantly higher EDSS scores, anti-aquporin-4 immunoglobulin G titers, more dense cerebrospinal fluid protein concentrations, white blood cell counts, myelin basic protein levels and more dense complement 3 concentrations than found in the comparative normal BBB permeability group. The albumin index was positively correlated to the length of lesions in spinal cord. Conclusions: BBB permeability was associated with clinical features, laboratory results and radiological data of NMOSD patients, and may be a potential biomarker to predict disease severity and clinical characteristics of NMOSD.

Brain medical image diagnosis based on corners with importance-values

BACKGROUND

Brain disorders are one of the top causes of human death. Generally, neurologists analyze brain medical images for diagnosis. In the image analysis field, corners are one of the most important features, which makes corner detection and matching studies essential. However, existing corner detection studies do not consider the domain information of brain. This leads to many useless corners and the loss of significant information. Regarding corner matching, the uncertainty and structure of brain are not employed in existing methods. Moreover, most corner matching studies are used for 3D image registration. They are inapplicable for 2D brain image diagnosis because of the different mechanisms. To address these problems, we propose a novel corner-based brain medical image classification method. Specifically, we automatically extract multilayer texture images (MTIs) which embody diagnostic information from neurologists. Moreover, we present a corner matching method utilizing the uncertainty and structure of brain medical images and a bipartite graph model. Finally, we propose a similarity calculation method for diagnosis.

RESULTS

Brain CT and MRI image sets are utilized to evaluate the proposed method. First, classifiers are trained in N-fold cross-validation analysis to produce the best θ and K. Then independent brain image sets are tested to evaluate the classifiers. Moreover, the classifiers are also compared with advanced brain image classification studies. For the brain CT image set, the proposed classifier outperforms the comparison methods by at least 8% on accuracy and 2.4% on F1-score. Regarding the brain MRI image set, the proposed classifier is superior to the comparison methods by more than 7.3% on accuracy and 4.9% on F1-score. Results also demonstrate that the proposed method is robust to different intensity ranges of brain medical image.

CONCLUSIONS

In this study, we develop a robust corner-based brain medical image classifier. Specifically, we propose a corner detection method utilizing the diagnostic information from neurologists and a corner matching method based on the uncertainty and structure of brain medical images. Additionally, we present a similarity calculation method for brain image classification. Experimental results on two brain image sets show the proposed corner-based brain medical image classifier outperforms the state-of-the-art studies.

A case report: Non-alcoholic Wernicke encephalopathy associated with polyneuropathy

We report a rare case of non-alcoholic Wernicke encephalopathy (WE) with polyneuropathy. A 24-year-old woman who had recently served a 4-month prison sentence and underwent a short period of dieting manifested slow response, weakness, language disorder and amnesia. Brain magnetic resonance imaging (MRI) revealed typical lesions of WE. Examination of nerve conduction velocity revealed sensory-motor axonal polyneuropathy. The patient was immediately treated with thiamine. Neurological symptoms were alleviated in a few days and abnormal signals were markedly decreased in a follow-up MRI 1 week later. Polyneuropathy symptoms ameliorated during hospital therapy and significantly improved after 4 months. This case suggests that WE may be associated with polyneuropathy in non-alcoholic patients. Early thiamine treatment in symptomatic patients may improve prognosis.

The Neuroimmune Response to Surgery - An Exploratory Study of Trauma-Induced Changes in Innate Immunity and Heart Rate Variability

Surgery triggers a systemic inflammatory response that ultimately impacts the brain and associates with long-term cognitive impairment. Adequate regulation of this immune surge is pivotal for a successful surgical recovery. We explored the temporal immune response in a surgical cohort and its associations with neuroimmune regulatory pathways and cognition, in keeping with the growing body of evidence pointing towards the brain as a regulator of peripheral inflammation. Brain-to-immune communication acts through cellular, humoral and neural pathways. In this context, the vagal nerve and the cholinergic anti-inflammatory pathway (CAP) have been shown to modify peripheral immune cell activity in both acute and chronic inflammatory conditions. However, the relevance of neuroimmune regulatory mechanisms following a surgical trauma is not yet elucidated. Twenty-five male patients undergoing elective laparoscopic abdominal surgery were included in this observational prospective study. Serial blood samples with extensive immune characterization, assessments of heart rate variability (HRV) and cognitive tests were performed before surgery and continuing up to 6 months post-surgery. Temporal immune responses revealed biphasic reaction patterns with most pronounced changes at 5 hours after skin incision and 14 days following surgery. Estimations of cardiac vagal nerve activity through HRV recordings revealed great individual variations depending on the pre-operative HRV baseline. A principal component analysis displayed distinct differences in systemic inflammatory biomarker trajectories primarily based on pre-operative HRV, with potiential consequences for long-term surgical outcomes. In conclusion, individual pre-operative HRV generates differential response patterns that associate with distinct inflammatory trajectories following surgery. Long-term surgical outcomes need to be examined further in larger studies with mixed gender cohorts.

Role of the SphK-S1P-S1PRs pathway in invasion of the nervous system by SARS-CoV-2 infection

Global spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still ongoing. Before an effective vaccine is available, the development of potential treatments for resultant coronavirus disease 2019 (COVID-19) is crucial. One of the disease hallmarks is hyper-inflammatory responses, which usually leads to a severe lung disease. Patients with COVID-19 also frequently suffer from neurological symptoms such as acute diffuse encephalomyelitis, brain injury and psychiatric complications. The metabolic pathway of sphingosine-1-phosphate (S1P) is a dynamic regulator of various cell types and disease processes, including the nervous system. It has been demonstrated that S1P and its metabolic enzymes, regulating neuroinflammation and neurogenesis, exhibit important functions during viral infection. S1P receptor 1 (S1PR1) analogues including AAL-R and RP-002 inhibit pathophysiological responses at the early stage of H1N1 virus infection and then play a protective role. Fingolimod (FTY720) is an S1P receptor modulator and is being tested for treating COVID-19. Our review provides an overview of SARS-CoV-2 infection and critical role of the SphK-S1P-SIPR pathway in invasion of SARS-CoV-2 infection, particularly in the central nervous system (CNS). This may help design therapeutic strategies based on the S1P-mediated signal transduction, and the adjuvant therapeutic effects of S1P analogues to limit or prevent the interaction between the host and SARS-CoV-2, block the spread of the SARS-CoV-2, and consequently treat related complications in the CNS.

Clinical Characteristics and Prognosis of Anti-AChR Positive Myasthenia Gravis Combined With Anti-LRP4 or Anti-Titin Antibody

OBJECTIVE

This study aimed to summarize the clinical characteristics and prognosis of patients with anti- acetylcholine receptor (AChR) positive myasthenia gravis (MG) with a combination of anti-LRP4 or Titin antibodies.

METHODS

A total of 188 patients with generalized MG before immunotherapy were retrospectively collected and then divided into three groups: single anti-AChR positive-MG (AChR-MG, 101 cases), anti-AChR combined with anti-low-density lipoprotein receptor-related protein four-positive MG (AChR+LRP4-MG, 29 cases), and anti-AChR combined with anti-Titin-positive MG (AChR+Titin-MG, 58 cases). Clinical manifestations, therapeutic responses to immunotherapy, and follow-up information were analyzed.

RESULTS

Of the 188 seropositive MG patients, 29 (15.4%) were positive for both AChR and LRP4 antibodies, and 58 (30.9%) were positive for both AChR and Titin antibodies. The mean disease onset ages in the three groups were 47.41 ± 7.0, 49.81 ± 9.2, and 48.11 ± 6.5 years, respectively. AChR+LRP4-MG showed female predominance (27.6% were males and 72.4% were females), with mild overall clinical symptoms. The AChR+Titin-MG group showed shorter times for conversion to generalized MG (5.14 ± 0.0 months) than the AChR-MG group (11.69 ± 0.0 months) and the AChR+LRP4-MG group (13.08 ± 0.5 months; P < 0.001 in both cases). Furthermore, AChR+Titin-MG group had increased bulbar dysfunction, higher incidences of thymoma (32.8 vs. 19.8% and 3.4%, P=0.035), more severe quantitative MG scores, as assessed by both QMG scores [15.5 (11.75-22.5) vs. 13 (8-19), P = 0.005; and 9 (6-14) P < 0.001], and MG-ADL scores [10 (8-13) vs. 8 (5-13), P = 0.018; and 6 (4-8), P < 0.001]. Treatment for AChR+Titin-MG was largely dependent on corticosteroids and immunosuppressive agents (56.7 vs. 19.2% and 16.7%, p = 0.028). The rates of achieving s(MMS) or better within 2 years following immunotherapy in the three groups were 51.5, 62.1, and 51.7%, respectively (P = 0.581).

CONCLUSION

Clinical symptoms of anti-AChR positive MG combined with Titin antibody were more severe and progressed faster than those in the AChR + LRP4 and AChR groups. Regardless of antibody status, all patients responded well to immunotherapy and had relatively good prognoses.

Genetic Causal Association Between the Gut Microbiome and Intracranial Aneurysm and Subarachnoid Hemorrhage: A Two-Sample Mendelian Randomization Study

INTRODUCTION

The causal association between the gut microbiome and the risk of intracranial aneurysm (IA), subarachnoid hemorrhage (SAH), and unruptured aneurysm (uIA) is unclear.

METHODS

The single nucleotide polymorphisms concerning gut microbiome were retrieved from the gene-wide association study (GWAS) of the MiBioGen consortium. The summary-level datasets of IA and SAH were obtained from the GWAS meta-analysis of the International Stroke Genetics Consortium (ISGC). Inverse variance weighting (IVW) was utilized as the primary method, complemented with sensitivity analyses for pleiotropy and increasing robustness.

RESULTS

Five, seven, and six bacterial traits were found to have a causal effect on IA, SAH, and uIA, respectively (IVW, all P < 0.05). Family.Porphyromonadaceae and genus.Bilophila were common protective bacterial features for both SAH and uIA. The heterogeneity and pleiotropy analyses confirmed the robustness of IVW results.

CONCLUSION

Our study demonstrates that gut microbiomes may exert therapeutic effects on IA, uIA, and SAH, providing clinical implications for the development of novel biomarkers and therapeutic targets.

Deamidation-related blood biomarkers show promise for early diagnostics of neurodegeneration

BACKGROUND

The strongest risk factor of neurodegenerative diseases (NDDs) is aging. Spontaneous asparaginyl deamidation leading to formation of isoaspartate (isoAsp) has been correlated with protein aggregation in NDDs.

METHODS

Two cohorts consisting of 140 subjects were studied. Cohort 1 contained patients with AD and healthy controls, while Cohort 2 recruited subjects with mild cognitive impairment (MCI), vascular dementia (VaD), frontotemporal dementia (FTD), Parkinson's disease (PD) and healthy controls. The levels of isoAsp in plasma human albumin (HSA), the most abundant protein in plasma, as well as the levels of immunoglobulin G (IgG) specific against deamidated HSA were measured. Apart from the memory tests, plasma biomarkers for NDDs reported in literature were also quantified, including amyloid beta (Aβ) peptides Aβ40 and Aβ42, neurofilament light protein (NfL), glial fibrillary acidic protein (GFAP) and phosphorylated tau 181 (p-tau181) protein.

RESULTS

Deamidation products of blood albumin were significantly elevated in vascular dementia and frontotemporal dementia (P < 0.05), but less so in PD. Intriguingly, the deamidation levels were significantly (P < 0.01) associated with the memory test scores for all tested subjects. Deamidation biomarkers performed superiorly (accuracy up to 92%) compared with blood biomarkers Aß42/Aß40, NfL, GFAP and p-tau181 in separating mild cognitive impairment from healthy controls.

CONCLUSION

We demonstrated the diagnostic capacity of deamidation-related biomarkers in predicting NDDs at the early stage of disease, and the biomarker levels significantly correlated with cognitive decline, strongly supporting the role of deamidation in triggering neurodegeneration and early stages of disease development. Prospective longitudinal studies with a longer observation period and larger cohorts should provide a more detailed picture of the deamidation role in NDD progression.

Antigen receptor stimulation induces purifying selection against pathogenic mitochondrial tRNA mutations

Pathogenic mutations in mitochondrial (mt) tRNA genes that compromise oxidative phosphorylation (OXPHOS) exhibit heteroplasmy and cause a range of multisyndromic conditions. Although mitochondrial disease patients are known to suffer from abnormal immune responses, how heteroplasmic mtDNA mutations affect the immune system at the molecular level is largely unknown. Here, in mice carrying pathogenic C5024T in mt-tRNAAla and in patients with mitochondrial encephalomyopathy, lactic acidosis, stroke-like episodes (MELAS) syndrome carrying A3243G in mt-tRNALeu, we found memory T and B cells to have lower pathogenic mtDNA mutation burdens than their antigen-inexperienced naive counterparts, including after vaccination. Pathogenic burden reduction was less pronounced in myeloid compared with lymphoid lineages, despite C5024T compromising macrophage OXPHOS capacity. Rapid dilution of the C5024T mutation in T and B cell cultures could be induced by antigen receptor-triggered proliferation and was accelerated by metabolic stress conditions. Furthermore, we found C5024T to dysregulate CD8+ T cell metabolic remodeling and IFN-γ production after activation. Together, our data illustrate that the generation of memory lymphocytes shapes the mtDNA landscape, wherein pathogenic variants dysregulate the immune response.

Novel mitochondrial alanyl-tRNA synthetase 2 (AARS2) heterozygous mutations in a Chinese patient with adult-onset leukoencephalopathy

BACKGROUND

Missense mutations in the mitochondrial alanyl-tRNA synthetase 2 (AARS2) gene are clinically associated with infantile mitochondrial cardiomyopathy or adult-onset leukoencephalopathy with early ovarian failure. To date, approximately 40 cases have been reported related to AARS2 mutations, while its genetic and phenotypic spectrum remains to be defined.

CASE PRESENTATION

We identified a 24-year-old Chinese female patient with adult-onset leukoencephalopathy carrying novel compound heterozygous pathogenic mutations in the AARS2 gene (c.718C > T and c.1040 + 1G > A) using a whole-exome sequencing approach.

CONCLUSIONS

Our findings further extend the mutational spectrum of AARS2-related leukoencephalopathy and highlight the importance of the whole-exome sequencing in precisely diagnosing adult-onset leukoencephalopathies.