Differentiating central nervous system demyelinating disorders: The role of clinical, laboratory, imaging characteristics and peripheral blood type I interferon activity

Sugar utilization by microglia in Alzheimer's disease

Diabetes is a major risk factor for Alzheimer's disease (AD), yet the effect of specific carbohydrate sources in the diet on AD pathology remains unclear. The primary neuroimmune cell, microglia, undergo a metabolic shift during neuroinflammation associated with AD pathology. We utilized existing gene expression data and identified changes in sugar transporters (increased Slc2a1 (glucose) and decreased Slc2a5 (fructose) expression). To examine gene expression with respect to primary sugar source, N9 cells, a mouse microglia cell line, were cultured in glucose or fructose supplemented media and stimulated with lipopolysaccharide (LPS). RNA-sequencing analyses indicated significant changes between control and sugar supplemented media and several differentially expressed genes between glucose and fructose media. Concurrently, 5XFAD mice received equicaloric diets with specific carbohydrate sources: dextrose or fructose. Regardless of diet, sex, or genotype, all mice developed high blood sugar levels; confocal microscopy analyses indicated similar amyloid plaque burden and microglial response relative to the control diet, but there was a change in the microglial response between dextrose and fructose fed mice. Overall, these data indicate microglia preferentially express sugar transporters and sugar source may influence microglial reactivity in response to plaque pathology.

Recent advances in the diagnosis and management of neuropsychiatric lupus

Neuropsychiatric manifestations of systemic lupus erythematosus (SLE) are common and frequently associated with a substantial negative impact on health outcomes. The pathogenesis of neuropsychiatric SLE (NPSLE) remains largely unknown, but a single pathogenic mechanism is unlikely to be responsible for the heterogeneous array of clinical manifestations, and a combination of inflammatory and ischaemic mechanistic pathways have been implicated. Currently, valid and reliable biomarkers for the diagnosis of NPSLE are lacking, and differentiating NPSLE from nervous system dysfunction not caused by SLE remains a major challenge for clinicians. However, correct attribution is essential to ensure timely institution of appropriate treatment. In the absence of randomized clinical trials on NPSLE, current treatment strategies are derived from clinical experience with different therapeutic modalities and their efficacy in the management of other manifestations of SLE or of neuropsychiatric disease in non-SLE populations. This Review describes recent advances in the understanding of NPSLE that can inform diagnosis and management, as well as unanswered questions that necessitate further research.

A rare case of systemic lupus erythematosus-associated neuromyelitis optica spectrum disorder with cystic lesions and dual seropositivity for anti-AQP4 and anti-MOG antibodies

Key Clinical Message

In patients with SLE, concurrent NMOSD can manifest with optic neuritis and transverse myelitis. AQP-4 antibody positivity confirms the diagnosis. Prompt treatment is critical to manage the acute symptoms and prevent relapses, as highlighted by a young patient's case with optic neuritis and extensive spinal cord lesions.

Abstract

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disorder of the central nervous system that affects the optic nerve and spinal cord. It is associated with autoantibodies against aquaporin-4 (AQP-4) and/or myelin oligodendrocytes glycoproteins. It is diagnosed based on clinical, radiological, and serological criteria, and treated with immunosuppressants in the acute phase. Long-term immunosuppression is essential to prevent potential relapses. In this case report, we present the case of a 19-year-old female patient with systemic lupus erythematosus (SLE), who presented with blurriness and loss of vision in her left eye. Optical coherence tomography was normal, but a gadolinium-enhanced cervico-dorsal MRI showed multiple lesions extending from the brainstem to the C7-T1 junction suggestive of longitudinally extensive transverse myelitis (LETM), the largest of which was a cystic lesion at the cervico-spinal junction. A contrast injection also revealed left optic neuritis. Cerebrospinal fluid analysis showed elevated IgG and red blood cell count, but no oligoclonal bands. The patient tested positive for AQP-4 autoantibodies, confirming the diagnosis of NMOSD. Treatment with intravenous methylprednisolone led to partial improvement, but the patient experienced a relapse with severe neurological symptoms, including tetraplegia and bladder and bowel dysfunction. This case illustrates the importance of considering NMOSD in the differential diagnosis of patients with SLE who present with optic neuritis and/or myelitis, especially when MRI findings are suggestive of LETM. Early diagnosis and adherence to treatment are crucial to prevent further relapses and deleterious sequelae.

Type I Interferons in Systemic Autoimmune Rheumatic Diseases: Pathogenesis, Clinical Features and Treatment Options

Type I interferon (IFN) pathway dysregulation plays a crucial role in the pathogenesis of several systemic autoimmune rheumatic diseases (SARDs), including systemic lupus erythematosus (SLE), Sjögren's disease (SjD), systemic sclerosis (SSc), dermatomyositis (DM) and rheumatoid arthritis (RA). Genetic and epigenetic alterations have been involved in dysregulated type I IFN responses in systemic autoimmune disorders. Aberrant type I IFN production and secretion have been associated with distinct clinical phenotypes, disease activity, and severity as well as differentiated treatment responses among SARDs. In this review, we provide an overview of the role of type I IFNs in systemic autoimmune diseases including SLE, RA, SjD, SSc, and DM focusing on pathophysiological, clinical, and therapeutical aspects.

Gene Signature of Regulatory T Cells Isolated from Children with Selective IgA Deficiency and Common Variable Immunodeficiency

Selective IgA deficiency (SIgAD) is the most common form and common variable immunodeficiency (CVID) is the most symptomatic form of predominant antibody deficiency. Despite differences in the clinical picture, a similar genetic background is suggested. A common feature of both disorders is the occurrence of autoimmune conditions. Regulatory T cells (Tregs) are the major immune cell type that maintains autoimmune tolerance. As the different types of abnormalities of Treg cells have been associated with autoimmune disorders in primary immunodeficiency (PID) patients, in our study we aimed to analyze the gene expression profiles of Treg cells in CVID and SIgAD patients compared to age-matched healthy controls. The transcriptome-wide gene profiling was performed by microarray technology. As a result, we analyzed and visualized gene expression patterns of isolated population of Treg cells. We showed the differences at the gene level between patients with and without autoimmunizations. Our findings suggest that the gene signatures of Treg cells isolated from SIgAD and CVID patients differ from age-matched healthy controls and from each other, presenting transcriptional profiles enriched in innate immune or Th response, respectively. The occurrence of autoimmunity in both types of PID is associated with down-regulation of class I IFNs signaling pathways. In summary, our findings improve our understanding of Treg dysfunctions in patients with common PIDs and associated autoimmunity.

An Observational Study of Multi-Faceted Demyelinating Disorders

BACKGROUND AND OBJECTIVES

Idiopathic inflammatory demyelinating diseases of the central nervous system (IIDCDs) are wide-ranging disorders due to their similarities and differences. In order to address these conditions, studying their characteristics is essential. The endpoints of our study were to assess the incidence, presenting features, MRI findings, and predictors of disease progression of prevalent demyelinating disorders.

MATERIAL AND METHODS

This prospective, observational study was conducted at Srirama Chandra Bhanja (SCB) Medical College and Hospital, India, from August 2018 to November 2021. Individuals of 18-65 years of age with common demyelinating disorders were assessed at baseline, six, 12, and 24 months. Univariate and multivariate analyses were performed for the assessment of predictors. We used R software (version 4.2.1; R Foundation for Statistical Computing, Vienna, Austria) for data analysis.

RESULTS

Two hundred twenty (79%) of 278 enrolled participants completed this study. The mean age of the study population was 52.3±11.4 years. One hundred thirty-eight (63%) of them were males. The most common IIDCD in our study was neuromyelitis optica spectrum disorder (NMOSD: 87, 39.5%), followed by multiple sclerosis (MS: 72, 32.7%), acute transverse myelitis (ATM: 35, 15.9%), and acute disseminated encephalomyelitis (ADEM: 26, 11.8%). The univariate analysis revealed that male gender, diabetes mellitus, and history of smoking or alcoholism were significant predictors of the disease progression.

CONCLUSION

The IIDCDs were polysymptomatic at the initial presentation. Male diabetics are more prone to progressive disorders. However, multivariate analysis did not provide statistically significant results.

Cerebrospinal Fluid Biomarkers in Differential Diagnosis of Multiple Sclerosis and Systemic Inflammatory Diseases with Central Nervous System Involvement

BACKGROUND

Diagnosis of multiple sclerosis (MS) is established on criteria according to clinical and radiological manifestation. Cerebrospinal fluid (CSF) analysis is an important part of differential diagnosis of MS and other inflammatory processes in the central nervous system (CNS).

METHODS

In total, 242 CSF samples were collected from patients undergoing differential MS diagnosis because of the presence of T2-hyperintensive lesions on brain MRI. The non-MS patients were subdivided into systemic inflammatory diseases with CNS involvement (SID) or cerebrovascular diseases (CVD) or other non-inflammatory diseases (NID). All samples were analyzed for the presence of oligoclonal bands and ELISA was performed for detection of: INF gamma, IL-6, neurofilaments light chain (NF-L), GFAP, CHI3L1, CXCL13, and osteopontin.

RESULTS

The level of IL-6 (p = 0.024), osteopontin (p = 0.0002), and NF-L (p = 0.002) was significantly different among groups. IL-6 (p = 0.0350) and NF-L (p = 0.0015) level was significantly higher in SID compared to NID patients. A significantly higher level of osteopontin (p = 0.00026) and NF-L (p = 0.002) in MS compared to NID population was noted. ROC analysis found weak diagnostic power for osteopontin and NFL-L.

CONCLUSIONS

The classical and non-standard markers of inflammatory process and neurodegeneration do not allow for sufficient differentiation between MS and non-MS inflammatory CNS disorders. Weak diagnostic power observed for the osteopontin and NF-L needs to be further investigated.

The role of type I IFN in autoimmune and autoinflammatory diseases with CNS involvement

Type I interferons (IFNs) are major mediators of innate immunity, with well-known antiviral, antiproliferative, and immunomodulatory properties. A growing body of evidence suggests the involvement of type I IFNs in the pathogenesis of central nervous system (CNS) manifestations in the setting of chronic autoimmune and autoinflammatory disorders, while IFN-β has been for years, a well-established therapeutic modality for multiple sclerosis (MS). In the present review, we summarize the current evidence on the mechanisms of type I IFN production by CNS cellular populations as well as its local effects on the CNS. Additionally, the beneficial effects of IFN-β in the pathophysiology of MS are discussed, along with the contributory role of type I IFNs in the pathogenesis of neuropsychiatric lupus erythematosus and type I interferonopathies.