CNS Demyelination with TNF-α Blockers

Neurological disorders following the use of tumor necrosis factor-α inhibitors in inflammatory bowel disease patients: a real-world pharmacovigilance analysis

BACKGROUND

Tumor necrosis factor-α inhibitors (TNFis) are used for the treatment of inflammatory bowel disease (IBD). The aim of this study was to evaluate the association between neurological adverse events (AEs) and TNFi use.

METHODS

Data of TNFis indicated for IBD were collected from the Food and Drug Administration Adverse Event Reporting System (FAERS) from the marketed date to the second quarter of 2023. The reporting odds ratio (ROR) and a Bayesian confidence propagation neural network were used to identify signals.

RESULTS

A total of 4,964 neurological AEs were reported in the IBD population. Infliximab had 3 signals, including demyelination [ROR (95% CI): 1.69 (1.33,2.15)], meningitis listeria [ROR (95% CI): 5.05 (3.52,7.25)], and optic neuritis [ROR (95% CI): 1.72 (1.3,2.26)]. The signals for adalimumab were gait disturbance [ROR (95% CI): 1.43 (1.32,1.56)] and muscular weakness [ROR (95% CI): 1.4 (1.27,1.55)]. A peripheral neuropathy signal was found for adalimumab [ROR (95% CI): 1.34 (1.18,1.53)] and certolizumab pegol [ROR (95% CI): 1.49 (1.07,2.08)]. However, there were no signals among neurological AEs for golimumab.

CONCLUSION

Neurological signals were detected for TNFi use, indicating that the risk of neurological AEs requires additional attention in clinical use of TNFis.

Epstein-Barr virus-encoded BART9 and BART15 miRNAs are elevated in exosomes of cerebrospinal fluid from relapsing-remitting multiple sclerosis patients

Epstein-Barr virus (EBV) infection is approved as the main environmental trigger of multiple sclerosis (MS). In this path, we quantified ebv-miR-BART9-3p and ebv-miR-BART15 in exosomes of cerebrospinal fluid (CSF) of untreated relapsing-remitting MS (RRMS) patients in comparison with the control group. Interestingly, patients displayed significant upregulation of ebv-miR-BART9-3p (18.4-fold) and ebv-miR-BART15 (3.1-fold) expression in CSF exosomes. Moreover, the expression levels of hsa-miR-21-5p and hsa-miR-146a-5p were found to be significantly elevated in the CSF samples obtained from the patient group compared to those obtained from the HC group. The levels of Interferon-gamma (IFN-γ), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-17 (IL-17), interleukin-23 (IL-23), transforming growth factor beta (TGF-β), and tumor necrosis factor-alpha (TNF-α) were observed to be significantly elevated in the serum and CSF exosomes of the patients. The highest increase was observed in TGF-β (8.5-fold), followed by IL-23 (3.9-fold) in CSF exosomes. These findings are in agreement with the association between EBV infection and inflammatory cytokines induction. Furthermore, the ratios of TGF-β: TNF-α and TGF-β: IFN-γ attained values of 4 to 16.4 and 1.3 to 3.6, respectively, in the CSF exosomes of the patients, in comparison to those of the control group. These findings show EBV activity in RRMS patients is different from that of healthy ones. Elevation of ebv-miR-BART9-3p, ebv-miR-BART15, and inflammatory cytokines expression in CSF exosomes in RRMS patients provides a substantial link between EBV activity and the onset of the disease, as well as the transition from EBV infection to MS.

TNF-alfa Gene Polymorphism Associations with Multiple Sclerosis

Background:TNF-α has a dual role in multiple sclerosis (MS), contributing to both protective and harmful effects. It activates immune cells, promotes the formation of inflammatory lesions in the central nervous system, and stimulates the production of other pro-inflammatory cytokines and chemokines, leading to myelin destruction and neuronal damage. Our research focused on investigating the relationship between TNF-alpha (rs1800630, rs1800629, and rs361525) gene polymorphisms and MS. Methods: 250 healthy controls and 250 multiple sclerosis (MS) patients were included in the study. DNA was extracted from leucocytes from peripheral venous blood by salt precipitation. Single nucleotide polymorphisms (SNPs) were tested using RT-PCR. Statistical analysis of the data was performed using IBM SPSS Statistics 29.0 data analysis software. Results: The analysis revealed that the rs361525 AG genotype was significantly less frequent in the MS group compared to the control group (4.0% vs. 7.2%, p = 0.042). Sex-specific analysis showed a significant difference in genotype distribution (GG, AG, AA) among males between the MS group and the control group (97.7%, 0%, 2.3% vs. 90.6%, 9.4%, 0%, p = 0.005). For the rs1800629 polymorphism, significant results were also found. In subjects younger than 39 years, the A allele was significantly less frequent in the MS group than in the control group (8.6% vs. 15.0%, p = 0.030). The most robust model indicated that the AA genotype reduced the odds of MS by approximately 2 fold compared to the AG + GG genotype (p = 0.044), and each A allele reduced the odds of MS by approximately 2 fold (p = 0.028). The rs1800630 A allele was significantly more common in males in the MS group than in the control group (21.0% vs. 12.9%, p = 0.046). Conclusions: In conclusion, our study identifies significant associations between TNF-alpha gene variants and MS. Specifically, the rs631525 AG genotype was less common in the MS group, with notable sex-specific differences observed. The rs1800629 A allele was statistically significantly less frequent in the MS group than in the control group, and the AA genotype reduced the odds of MS occurrence by ~2 fold compared with the AG + GG genotypes. Additionally, each A allele of rs1800629 was linked to a 2-fold decreased odds of MS occurrence. In males, the rs1800630 A allele was more frequent in the MS group. These findings highlight the relevance of TNF-alpha genetic variations in MS susceptibility, suggesting potential avenues for further research and therapeutic exploration.

Risk of multiple sclerosis in patients with psoriasis receiving anti-IL-17 agents: A case-based review

Biologics approved for psoriasis exhibit favorable safety profiles, and serious adverse events have rarely been reported. In this report, we present the case of a patient treated with ixekizumab, an anti-interleukin (IL)-17 agent, who 8 months later developed multiple sclerosis (MS). We also review the available literature regarding the use of anti-IL-17 agents in the context of psoriasis and pre-existing or new-onset demyelination. Eight case reports were evaluated as relevant and are presented in our report. In most of the cases secukinumab or ixekizumab administration adequately controlled both skin and pre-existing neurological clinical manifestations. However, there has been a report of MS exacerbation under secukinumab treatment and the occurrence of myelitis in a patient receiving ixekizumab. While the anti-IL-17-biologic-mediated induction of inflammatory events in the central nervous system has not been proven and a causal relationship is lacking, such a probability should be considered in extremely rare cases.

Multifocal leukoencephalopathy in a patient medicated with etanercept and methotrexate for rheumatoid arthritis

Methotrexate (MTX) and etanercept are commonly used in the treatment of rheumatoid arthritis (RA). Several important adverse events, including central nervous system lesions, have been reported during RA treatment. Among them, MTX-induced leukoencephalopathy is a recognized complication that is often observed following intrathecal or intravenous MTX administration. Herein, we report a case of a RA patient who was diagnosed with multifocal leukoencephalopathy during etanercept and MTX therapy. A 77-year-old Chinese woman with a 3-year history of RA had been taking subcutaneous etanercept and low-dose oral MTX since February 2021. Five months after the initial administration, she developed cognitive impairment and experienced a dropped attack. She was then admitted to our hospital in June 2021. T2-weighted magnetic resonance imaging (MRI) images revealed disseminated lesions in the white matter of the brain. Based on these MRI findings and extensive clinical investigation that excluded other possible causes of white matter lesions, she was suspected of having a demyelinating disorder. There was no evidence suggesting other neurological disorders. High-dose corticosteroid was administered, which resulted in improved cognitive impairment. This case report illustrates an important example of multifocal leukoencephalopathy induced by the combined use of etanercept and MTX, which resolved with high-dose corticosteroid. With the recent emphasis on various biologic agents for treatment of RA, our case highlights the importance of identifying leukoencephalopathy that may be induced by various biologics.

Immune System Dysregulation in the Progression of Multiple Sclerosis: Molecular Insights and Therapeutic Implications

Multiple sclerosis (MS), a prevalent neurological disorder, predominantly affects young adults and is characterized by chronic autoimmune activity. The study explores the immune system dysregulation in MS, highlighting the crucial roles of immune and non-neuronal cells in the disease's progression. This review examines the dual role of cytokines, with some like IL-6, TNF-α, and interferon-gamma (IFN-γ) promoting inflammation and CNS tissue injury, and others such as IL-4, IL-10, IL-37, and TGF-β fostering remyelination and protecting against MS. Elevated chemokine levels in the cerebrospinal fluid (CSF), including CCL2, CCL5, CXCL10, CXCL13, and fractalkine, are analyzed for their role in facilitating immune cell migration across the blood-brain barrier (BBB), worsening inflammation and neurodegeneration. The study also delves into the impact of auto-antibodies targeting myelin components like MOG and AQP4, which activate complement cascades leading to further myelin destruction. The article discusses how compromised BBB integrity allows immune cells and inflammatory mediators to infiltrate the CNS, intensifying MS symptoms. It also examines the involvement of astrocytes, microglia, and oligodendrocytes in the disease's progression. Additionally, the effectiveness of immunomodulatory drugs such as IFN-β and CD20-targeting monoclonal antibodies (e.g., rituximab) in modulating immune responses is reviewed, highlighting their potential to reduce relapse rates and delaying MS progression. These insights emphasize the importance of immune system dysfunction in MS development and progression, guiding the development of new therapeutic strategies. The study underscores recent advancements in understanding MS's molecular pathways, opening avenues for more targeted and effective treatments.

Choosing the right biologic treatment for moderate-to-severe plaque psoriasis: the impact of comorbidities

INTRODUCTION

Psoriasis is a chronic inflammatory skin disease often associated with several comorbidities, such as psoriatic arthritis, inflammatory bowel disease, obesity, diabetes mellitus or cardiovascular diseases, infections, or cancer, among others. With the progressive aging of the population, a growing number of patients with psoriasis can be expected to present multiple comorbidities. Currently, there is a wide range of biological treatments available for moderate to severe psoriasis, including tumor necrosis alpha (TNF) inhibitors, IL12/23 inhibitor, IL17 inhibitors, and IL23 inhibitors.

AREAS COVERED

This review aims to describe the specific characteristics of these drugs in relation to psoriasis comorbidities, in order to facilitate decision-making in clinical practice.

EXPERT OPINION

Some of the biological treatments can influence comorbidities, in some cases even improving them. Therefore, comorbidities are a key factor when deciding on one biological treatment over another. The development of new drugs is expanding the therapeutic arsenal for psoriasis. A high level of expertise in the field with a detailed knowledge of the characteristics of every drug is imperative to provide personalized medicine.

Adalimumab-induced central nervous system demyelination in a patient with rheumatoid arthritis

Adalimumab (Humira) is a human monoclonal antibody that belongs to the tumor necrosis factor (TNF) alpha antagonist class of medications. Central Nervous System (CNS) demyelination is a rare side effect of adalimumab, and only a few cases have been reported in the literature of patients who developed multiple sclerosis or other demyelinating patterns after using adalimumab. In this report, we present a case of CNS demyelination in a patient with rheumatoid arthritis that developed a few months after using adalimumab. Performing brain MRI for asymptomatic individuals prior to initiating anti-TNF alpha agents to exclude a pre-existing demyelinating disease may be worthwhile. Routine brain MRI for monitoring and surveillance may facilitate detecting cases early and avoid the development of permanent neurological disability. Further studies are needed to clarify the neurological safety of anti-TNF alpha agents.

Systemic meta-analysis: apigenin's effects on lung inflammation and oxidative stress

OBJECTIVE

This study aimed to investigate the potential anti-inflammatory and antioxidant effects of apigenin in rats with acute lung injury (ALI). We also examined changes in levels of inflammatory and antioxidant factors after apigenin treatment in a rat model of ALI.Methods: We searched several databases, including PubMed, Scopus, EMBASE, Web of Science, ProQuest, and GoogleScholar, to retrieve relevant articles for our systematic review and meta-analysis.Five studies with 226 rat models of ALI were included in this study. We investigated inflammatory factors and oxidative stress with the corresponding 95% confidence interval in three groups: 1. Group1 (control vs. ALI), 2. Group2 (ALI vs. apigenin10), and 3. Group3 (ALI vs. apigenin20).

RESULTS

Estimating the correlation and 95% confidence intervals for the inflammatory agents and oxidative stress in the intervention group (ALI), compared with that in the control group, respectively (correlation: 0.194; 95% confidence intervals, 0.101-0.282, p value = .001, z-value= 4.08) and (correlation: 0.099; 95% confidence intervals, 0.016-0.182, p value = .020, z value= 2.325). Estimating the correlation and 95% confidence intervals for the inflammatory agents and oxidative stress in the intervention group (apigenin 10 mg/kg), compared with that in the control group (ALI), respectively (correlation: 0.476; 95% confidence intervals, 0.391-0.553, p value = .001, z-value= 9.678) and (correlation: 0.415; 95% confidence intervals, 0.313-0.508, p value= .001, z-value= 7.349).

CONCLUSION

Apigenin may have potential anti-inflammatory and antioxidant effects in rat models of ALI. However, the efficacy of apigenin as a therapeutic strategy requires further investigation through prospective controlled randomized trials.

Siponimod Attenuates Neuronal Cell Death Triggered by Neuroinflammation via NFκB and Mitochondrial Pathways

Multiple sclerosis (MS) is the most common autoimmune demyelinating disease of the central nervous system (CNS), consisting of heterogeneous clinical courses varying from relapsing-remitting MS (RRMS), in which disability is linked to bouts of inflammation, to progressive disease such as primary progressive MS (PPMS) and secondary progressive MS (SPMS), in which neurological disability is thought to be linked to neurodegeneration. As a result, successful therapeutics for progressive MS likely need to have both anti-inflammatory and direct neuroprotective properties. The modulation of sphingosine-1-phosphate (S1P) receptors has been implicated in neuroprotection in preclinical animal models. Siponimod/BAF312, the first oral treatment approved for SPMS, may have direct neuroprotective benefits mediated by its activity as a selective (S1P receptor 1) S1P1 and (S1P receptor 5) S1P5 modulator. We showed that S1P1 was mainly present in cortical neurons in lesioned areas of the MS brain. To gain a better understanding of the neuroprotective effects of siponimod in MS, we used both rat neurons and human-induced pluripotent stem cell (iPSC)-derived neurons treated with the neuroinflammatory cytokine tumor necrosis factor-alpha (TNF-α). Cell survival/apoptotic assays using flow cytometry and IncuCyte live cell analyses showed that siponimod decreased TNF-α induced neuronal cell apoptosis in both rat and human iPSCs. Importantly, a transcriptomic analysis revealed that mitochondrial oxidative phosphorylation, NFκB and cytokine signaling pathways contributed to siponimod's neuroprotective effects. Our data suggest that the neuroprotection of siponimod/BAF312 likely involves the relief of oxidative stress in neuronal cells. Further studies are needed to explore the molecular mechanisms of such interactions to determine the relationship between mitochondrial dysfunction and neuroinflammation/neurodegeneration.

Nanobodies in cytokine‑mediated immunotherapy and immunoimaging (Review)

Cytokines are the main regulators of innate and adaptive immunity, mediating communications between the cells of the immune system and regulating biological functions, including cell motility, differentiation, growth and apoptosis. Cytokines and cytokine receptors have been used in the treatment of tumors and autoimmune diseases, and to intervene in cytokine storms. Indeed, the use of monoclonal antibodies to block cytokine‑receptor interactions, as well as antibody‑cytokine fusion proteins has exhibited immense potential for the treatment of tumors and autoimmune diseases. Compared with these traditional types of antibodies, nanobodies not only maintain a high affinity and specificity, but also have the advantages of high thermal stability, a high capacity for chemical manipulation, low immunogenicity, good tissue permeability, rapid clearance and economic production. Thus, nanobodies have extensive potential for use in the diagnosis and treatment of cytokine‑related diseases. The present review summarizes the application of nanobodies in cytokine‑mediated immunotherapy and immunoimaging.

Demyelinating plaque-associated uveitis

PURPOSE

To report the clinical and fluorescein angiographic (FA) features of demyelinating plaque-associated uveitis (DPU), a subset of uveitis in which patients have demyelinating plaques on the brain/cervical magnetic resonance image (MRI) but do not meet the criteria for multiple sclerosis (MS).

METHODS

In this retrospective observational study, Persian Patients were diagnosed with DPU and included if (1) they never satisfied the MS criteria, (2) all other possible etiologies were excluded, and (3) they were followed for at least 2 years.

RESULTS

After a median follow-up of 3 years (interquartile range, 2.0-5.3), 8 out of 40 (20%) patients diagnosed with DPU were excluded as they subsequently met the MS criteria. Of remaining 32 patients studied, the mean age was 36.3±9.9 (range 20-56 years), and 30 (93.8%) were female. Twenty-four (75.0%) showed bilateral involvement and 27 (84.4%) had insidious-chronic course. Uveitis was classified as intermediate (with or without anterior uveitis) in 29 (90.6%) and isolated anterior in 3 (9.4%) patients. Nine (28.1%) patients had at least one systemic neurological complaint. Ocular findings were: granulomatous keratic precipitates in 43/44 (97.7%) eyes; snowballs in 25/52 (48.1%) eyes; snowbanks in 4/52 (7.7%) eyes; cystoid macular edema in 20/56 (35.7%) eyes; and optic neuritis in 5/56 (8.9%) eyes. Visual acuity was ≥ 20/40 in 39 eyes (69.6%) at presentation which improved to 46 eyes (81.2%) at 2-year follow up. The two most frequent findings in FA were optic disc leakage/staining in 44/52 (81.5%) eyes, and peripheral retinal perivascular leakage in 39/52 (76.9%) eyes, which in 14/52 (26.9%) eyes extended beyond the equator.

CONCLUSION

DPU usually presents as a bilateral chronic granulomatous intermediate and, less often, isolated anterior uveitis, especially in females. Most are neurologically asymptomatic. Visual outcome is generally favorable. In FA, peripheral retinal perivascular leakage is common. DPU patients have an increased tendency to develop MS and should be prohibited from anti-TNF treatment.

The brain cytokine orchestra in multiple sclerosis: from neuroinflammation to synaptopathology

The central nervous system (CNS) is finely protected by the blood-brain barrier (BBB). Immune soluble factors such as cytokines (CKs) are normally produced in the CNS, contributing to physiological immunosurveillance and homeostatic synaptic scaling. CKs are peptide, pleiotropic molecules involved in a broad range of cellular functions, with a pivotal role in resolving the inflammation and promoting tissue healing. However, pro-inflammatory CKs can exert a detrimental effect in pathological conditions, spreading the damage. In the inflamed CNS, CKs recruit immune cells, stimulate the local production of other inflammatory mediators, and promote synaptic dysfunction. Our understanding of neuroinflammation in humans owes much to the study of multiple sclerosis (MS), the most common autoimmune and demyelinating disease, in which autoreactive T cells migrate from the periphery to the CNS after the encounter with a still unknown antigen. CNS-infiltrating T cells produce pro-inflammatory CKs that aggravate local demyelination and neurodegeneration. This review aims to recapitulate the state of the art about CKs role in the healthy and inflamed CNS, with focus on recent advances bridging the study of adaptive immune system and neurophysiology.

Multiple Sclerosis Risk Among Anti-tumor Necrosis Factor Alpha Users: A Methodological Review of Observational Studies Based on Real-world Data

Epidemiologic studies on the risk of multiple sclerosis (MS) or demyelinating events associated with anti-tumor necrosis factor alpha (TNFα) use among patients with rheumatic diseases or inflammatory bowel diseases have shown conflicting results. Causal directed acyclic graphs (cDAGs) are useful tools for understanding the differing results and identifying the structure of potential contributing biases. Most of the available literature on cDAGs uses language that might be unfamiliar to clinicians. This article demonstrates how cDAGs can be used to determine whether there is a confounder, a mediator or collider-stratification bias and when to adjust for them appropriately. We also use a case study to show how to control for potential biases by drawing a cDAG depicting anti-TNFα use and its potential to contribute to MS onset. Finally, we describe potential biases that might have led to contradictory results in previous studies that examined the effect of anti-TNFα and MS, including confounding, confounding by contraindication, and bias due to measurement error. Clinicians and researchers should be cognizant of confounding, confounding by contraindication, and bias due to measurement error when reviewing future studies on the risk of MS or demyelinating events associated with anti-TNFα use. cDAGs are a useful tool for selecting variables and identifying the structure of different biases that can affect the validity of observational studies.

Monoclonal Antibodies: What the Diagnostic Neuroradiologist Needs to Know

Monoclonal antibodies have become increasingly popular as novel therapeutics against a variety of diseases due to their specificity, affinity, and serum stability. Due to the nearly infinite repertoire of monoclonal antibodies, their therapeutic use is rapidly expanding, revolutionizing disease course and management, and what is now considered experimental therapy may soon become approved practice. Therefore, it is important for radiologists, neuroradiologists, and neurologists to be aware of these drugs and their possible different imaging-related manifestations, including expected and adverse effects of these novel drugs. Herein, we review the most commonly used monoclonal antibody-targeted therapeutic agents, their mechanism of action, clinical applications, and major adverse events with a focus on neurologic and neurographic effects and discuss differential considerations, to assist in the diagnosis of these conditions.

Pediatric Pars Planitis: A Review

PURPOSE

To provide an overview of pediatric pars planitis.

METHODS

Narrative literature review.

RESULTS

Pars planitis refers to the idiopathic subset of intermediate uveitis in which there is vitritis along with snowball or snowbank formation occurring in the absence of an associated infection or systemic disease. It is thought to be a T-cell mediated disease with a genetic predisposition. Pars planitis accounts for 5-26.7% of pediatric uveitis cases. Presentation is commonly bilateral but asymmetric, often with insidious onset of floaters and blurred vision. Although pars planitis is known to be a benign form of uveitis in most cases, severe complications secondary to chronic inflammation may arise, with cystoid macular edema being the most common cause of visual morbidity. Mild vitritis in the absence of symptoms, vision loss, or macular edema may be observed. Patients with severe vitritis and/or associated vision-threatening complications require prompt aggressive treatment. A stepladder approach including corticosteroids, immunosuppressive agents, anti‑tumor necrosis factor‑alpha and pars plana vitrectomy and/or laser photocoagulation is the most commonly used method for treatment of pars planitis.

CONCLUSION

Timely diagnosis and adequate treatment of pediatric pars planitis and associated complications are crucial in order to improve visual outcomes.

Predictive Factors for Magnetic Resonance Imaging Changes Suggestive of Demyelination in Adult Patients with Uveitis Scanned Prior to Commencing Adalimumab Therapy

PURPOSE

To report the predictive clinical factors for abnormal magnetic resonance imaging (MRI) scans suggestive of demyelination by analysis of MRI's performed for adult non-infectious uveitic patients prior to commencing adalimumab therapy.

METHODS

Retrospective case review of 240 patients was conducted in a single tertiary institution between November 2017 and March 2020. Aetiology of underlying disease, clinical characteristics, and MRI outcomes were analysed.

RESULTS

The presence of bilateral idiopathic intermediate uveitis (IIU) (p = .0048) and neurological symptoms (p = .028) were highly predictive of an abnormal MRI strongly suggestive of demyelination (MRSSD); 5 out of 64 scans (7.8%) with these clinical characteristics had MRSSD.

CONCLUSIONS

Tumor necrosis factor antagonist-induced demyelination is a concern in adalimumab use. We propose an MRI screening protocol to identify those at high risk of demyelination; positive results can be maximised by screening all patients with IIU and those with neurological symptoms.

B cell depletion modulates glial responses and enhances blood vessel integrity in a model of multiple sclerosis

Multiple sclerosis (MS) is characterized by a compromised blood-brain barrier (BBB) resulting in central nervous system (CNS) entry of peripheral lymphocytes, including T cells and B cells. While T cells have largely been considered the main contributors to neuroinflammation in MS, the success of B cell depletion therapies suggests an important role for B cells in MS pathology. Glial cells in the CNS are essential components in both disease progression and recovery, raising the possibility that they represent targets for B cell functions. Here, we examine astrocyte and microglia responses to B cell depleting treatments in an animal model of MS, experimental autoimmune encephalomyelitis (EAE). B cell depleted EAE animals had markedly reduced disease severity and myelin damage accompanied by reduced microglia and astrocyte reactivity 20 days after symptom onset. To identify potential initial mechanisms mediating functional changes following B cell depletion, astrocyte and microglia transcriptomes were analyzed 3 days following B cell depletion. In control EAE animals, transcriptomic analysis revealed astrocytic inflammatory pathways were activated and microglial influence on neuronal function were inhibited. Following B cell depletion, initial functional recovery was associated with an activation of astrocytic pathways linked with restoration of neurovascular integrity and of microglial pathways associated with neuronal function. These studies reveal an important role for B cell depletion in influencing glial function and CNS vasculature in an animal model of MS.

The Interface between Inflammatory Bowel Disease, Neuroinflammation, and Neurological Disorders

Inflammatory Bowel Disease (IBD) is a complex, chronic inflammatory condition affecting the gastrointestinal tract. IBD has been associated with a variety of neurologic manifestations including peripheral nerve involvement, increased risk of thrombotic, demyelinating and events. Furthermore, an evolving association between IBD and neurodegenerative disorders has been recognized, and early data suggests an increased risk of these disorders in patients diagnosed with IBD. The relationship between intestinal inflammatory disease and neuroinflammation is complex, but the bidirectional interaction between the brain-gut-microbiome axis is likely to play an important role in the pathogenesis of these disorders. Identification of common mechanisms and pathways will be key to developing potential therapies. In this review, we discuss the evolving interface between IBD and neurological conditions, with a focus on clinical, mechanistic, and potentially therapeutic implications.

Secondary Central Nervous System Demyelinating Disorders in the Elderly: A Narrative Review

Secondary demyelinating diseases comprise a wide spectrum group of pathological conditions and may either be attributed to a disorder primarily affecting the neurons or axons, followed by demyelination, or to an underlying condition leading to secondary damage of the myelin sheath. In the elderly, primary demyelinating diseases of the central nervous system (CNS), such as multiple sclerosis, are relatively uncommon. However, secondary causes of CNS demyelination may often occur and in this case, extensive diagnostic workup is usually needed. Infectious, postinfectious, or postvaccinal demyelination may be observed, attributed to age-related alterations of the immune system in this population. Osmotic disturbances and nutritional deficiencies, more commonly observed in the elderly, may lead to conditions such as pontine/extrapontine myelinolysis, Wernicke encephalopathy, and demyelination of the posterior columns of the spinal cord. The prevalence of malignancies is higher in the elderly, sometimes leading to radiation-induced, immunotherapy-related, or paraneoplastic CNS demyelination. This review intends to aid clinical neurologists in broadening their diagnostic approach to secondary CNS demyelinating diseases in the elderly. Common clinical conditions leading to secondary demyelination and their clinical manifestations are summarized here, while the current knowledge of the underlying pathophysiological mechanisms is additionally presented.

Role of tumor necrosis factor-alpha in the central nervous system: a focus on autoimmune disorders

Tumor necrosis factor-alpha (TNF-α) is a pleiotropic immune cytokine that belongs to the TNF superfamily of receptor ligands. The cytokine exists as either a transmembrane or a soluble molecule, and targets two distinct receptors, TNF-α receptor 1 (TNFR1) and TNF-α receptor 2 (TNFR2), which activate different signaling cascades and downstream genes. TNF-α cellular responses depend on its molecular form, targeted receptor, and concentration levels. TNF-α plays a multifaceted role in normal physiology that is highly relevant to human health and disease. In the central nervous system (CNS), this cytokine regulates homeostatic functions, such as neurogenesis, myelination, blood-brain barrier permeability and synaptic plasticity. However, it can also potentiate neuronal excitotoxicity and CNS inflammation. The pleiotropism of TNF-α and its various roles in the CNS, whether homeostatic or deleterious, only emphasizes the functional complexity of this cytokine. Anti-TNF-α therapy has demonstrated effectiveness in treating various autoimmune inflammatory diseases and has emerged as a significant treatment option for CNS autoimmune diseases. Nevertheless, it is crucial to recognize that the effects of this therapeutic target are diverse and complex. Contrary to initial expectations, anti-TNF-α therapy has been found to have detrimental effects in multiple sclerosis. This article focuses on describing the various roles, both physiological and pathological, of TNF-α in the CNS. Additionally, it discusses the specific disease processes that are dependent or regulated by TNF-α and the rationale of its use as a therapeutic target.

Therapeutic consequences in patients with both inflammatory rheumatic diseases and multiple sclerosis

Dealing with patients with both multiple sclerosis (MS) and inflammatory rheumatic disorders (IRDs) is not uncommon for a rheumatologist, as there is a statistical association between SpA and MS. As several CNS demyelinating events have been reported in patients treated with TNF inhibitor (TNFi), the pre-existing demyelinating disease was considered a contraindication for TNFi. However, this contraindication is mainly based on a randomized controlled trial in MS and not on large epidemiological studies. According to the last epidemiological studies, TNFi might not be an inducer of MS. Moreover, there are no clear recommendations on the use of the other DMARDs in patients suffering from an IRD and MS. In this review, we summarize the link between MS and IRDs and the impact of DMARDs on MS, especially TNFi. We also look at the impact of disease-modifying drugs for adults with MS and IRDs.

Selective Inhibition of Soluble Tumor Necrosis Factor Alters the Neuroinflammatory Response following Moderate Spinal Cord Injury in Mice

Clinical and animal model studies have implicated inflammation and glial and peripheral immune cell responses in the pathophysiology of spinal cord injury (SCI). A key player in the inflammatory response after SCI is the pleiotropic cytokine tumor necrosis factor (TNF), which exists both in both a transmembrane (tmTNF) and a soluble (solTNF) form. In the present study, we extend our previous findings of a therapeutic effect of topically blocking solTNF signaling after SCI for three consecutive days on lesion size and functional outcome to study the effect on spatio-temporal changes in the inflammatory response after SCI in mice treated with the selective solTNF inhibitor XPro1595 and compared to saline-treated mice. We found that despite comparable TNF and TNF receptor levels between XPro1595- and saline-treated mice, XPro1595 transiently decreased pro-inflammatory interleukin (IL)-1β and IL-6 levels and increased pro-regenerative IL-10 levels in the acute phase after SCI. This was complemented by a decrease in the number of infiltrated leukocytes (macrophages and neutrophils) in the lesioned area of the spinal cord and an increase in the number of microglia in the peri-lesion area 14 days after SCI, followed by a decrease in microglial activation in the peri-lesion area 21 days after SCI. This translated into increased myelin preservation and improved functional outcomes in XPro1595-treated mice 35 days after SCI. Collectively, our data suggest that selective targeting of solTNF time-dependently modulates the neuroinflammatory response by favoring a pro-regenerative environment in the lesioned spinal cord, leading to improved functional outcomes.

Role of Imaging Modalities and N-Acetylcysteine Treatment in Sepsis-Associated Encephalopathy

Sepsis-associated encephalopathy is a severe systemic infection complication. Although early stages involve pathophysiological changes, detection using conventional imaging is challenging. Glutamate chemical exchange saturation transfer and diffusion kurtosis imaging can noninvasively investigate cellular and molecular events in early disease stages using magnetic resonance imaging (MRI). N-Acetylcysteine, an antioxidant and precursor of glutathione, regulates neurotransmitter glutamate metabolism and participates in neuroinflammation. We investigated the protective role of n-acetylcysteine in sepsis-associated encephalopathy using a rat model and monitored changes in brain using magnetic resonance (MR) molecular imaging. Bacterial lipopolysaccharide was injected intraperitoneally to induce a sepsis-associated encephalopathy model. Behavioral performance was assessed using the open-field test. Tumor necrosis factor α and glutathione levels were detected biochemically. Imaging was performed using a 7.0-T MRI scanner. Protein expression, cellular damage, and changes in blood-brain barrier permeability were assessed using western blotting, pathological staining, and Evans blue staining, respectively. Lipopolysaccharide-induced rats showed reduced anxiety and depression after treatment with n-acetylcysteine. MR molecular imaging can identify pathological processes at different disease stages. Furthermore, rats treated with n-acetylcysteine showed increased glutathione levels and decreased tumor necrosis factor α, suggesting enhanced antioxidant capacity and inhibition of inflammatory processes, respectively. Western blot analysis showed reduced expression of nuclear factor kappa B (p50) protein after treatment, suggesting that n-acetylcysteine inhibits inflammation via this signaling pathway. Finally, n-acetylcysteine-treated rats showed reduced cellular damage by pathology and reduced extravasation of their blood-brain barrier by Evans Blue staining. Thus, n-acetylcysteine might be a therapeutic option for sepsis-associated encephalopathy and other neuroinflammatory diseases. Furthermore, noninvasive "dynamic visual monitoring" of physiological and pathological changes related to sepsis-associated encephalopathy was achieved using MR molecular imaging for the first time, providing a more sensitive imaging basis for early diagnosis, identification, and prognosis.

Neurologic Manifestations of Rheumatologic Disease

OBJECTIVE

This article describes the neurologic manifestations of systemic rheumatologic disorders.

LATEST DEVELOPMENTS

Although most have historically been classified as autoimmune disorders, rheumatologic diseases are increasingly conceptualized as distributed along a spectrum with various contributions of autoimmune (adaptive immune dysregulation) and autoinflammatory (innate immune dysregulation) mechanisms. Our evolving understanding of systemic immune-mediated disorders has been accompanied by an expansion in our differential diagnoses and therapeutic options.

ESSENTIAL POINTS

Rheumatologic disease involves both autoimmune and autoinflammatory mechanisms. Neurologic symptoms can be the first manifestation of these disorders, and familiarity with the systemic manifestations of specific diseases is essential to establish the correct diagnosis. Conversely, knowledge of the neurologic syndromes that are most likely to be associated with specific systemic disorders can help narrow the differential and increase confidence when attributing a neuropsychiatric symptom to an underlying systemic disorder.

Cross-reactive EBNA1 immunity targets alpha-crystallin B and is associated with multiple sclerosis

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system, for which and Epstein-Barr virus (EBV) infection is a likely prerequisite. Due to the homology between Epstein-Barr nuclear antigen 1 (EBNA1) and alpha-crystallin B (CRYAB), we examined antibody reactivity to EBNA1 and CRYAB peptide libraries in 713 persons with MS (pwMS) and 722 matched controls (Con). Antibody response to CRYAB amino acids 7 to 16 was associated with MS (OR = 2.0), and combination of high EBNA1 responses with CRYAB positivity markedly increased disease risk (OR = 9.0). Blocking experiments revealed antibody cross-reactivity between the homologous EBNA1 and CRYAB epitopes. Evidence for T cell cross-reactivity was obtained in mice between EBNA1 and CRYAB, and increased CRYAB and EBNA1 CD4+ T cell responses were detected in natalizumab-treated pwMS. This study provides evidence for antibody cross-reactivity between EBNA1 and CRYAB and points to a similar cross-reactivity in T cells, further demonstrating the role of EBV adaptive immune responses in MS development.

Focus on Anti-Tumour Necrosis Factor (TNF)-α-Related Autoimmune Diseases

Anti-tumour necrosis factor (TNF)-α agents have been increasingly used to treat patients affected by inflammatory bowel disease and dermatological and rheumatologic inflammatory disorders. However, the widening use of biologics is related to a new class of adverse events called paradoxical reactions. Its pathogenesis remains unclear, but it is suggested that cytokine remodulation in predisposed individuals can lead to the inflammatory process. Here, we dissect the clinical aspects and overall outcomes of autoimmune diseases caused by anti-TNF-α therapies.

The immunomodulatory roles of the gut microbiome in autoimmune diseases of the central nervous system: Multiple sclerosis as a model

The gut-associated lymphoid tissue is a primary activation site for immune responses to infection and immunomodulation. Experimental evidence using animal disease models suggests that specific gut microbes significantly regulate inflammation and immunoregulatory pathways. Furthermore, recent clinical findings indicate that gut microbes' composition, collectively named gut microbiota, is altered under disease state. This review focuses on the functional mechanisms by which gut microbes promote immunomodulatory responses that could be relevant in balancing inflammation associated with autoimmunity in the central nervous system. We also propose therapeutic interventions that target the composition of the gut microbiota as immunomodulatory mechanisms to control neuroinflammation.

Tumor necrosis factor-α inhibitor-related immune disorders

Biotechnological monoclonal antibodies and receptor antagonists capable of targeting specific inflammatory actors, such as cytokines, cytokines receptors, co-stimulatory molecules or leukocyte populations, have emerged as an alternative to conventional therapies for treating systemic inflammatory diseases with immune pathogenesis. However, there is no doubt that, with a frequency that is not exceptionally high but also not negligible, immunotherapies can favour the development of systemic and organ-specific immune-mediated disorders. It has become increasingly evident that interference with a specific immune pathway may favour the activation of opposing compensatory signalling, which may exacerbate underlying subclinical disorders or cause immune-mediated diseases completely different from the underlying disease. The 'compensatory immunological switch' has emerged primarily in patients treated with tumor necrosis factor (TNF) -α inhibitors, the first biological drugs approved for treating systemic inflammatory diseases with immune pathogenesis. In this Review, we describe the clinical features and predisposing factors of the main TNF-α inhibitor-related immune disorders, organising them into subclinical serological autoimmunity, autoimmune disorders other than those for which TNF-α inhibitors are indicated, and paradoxical reactions. We also discuss the underlying pathogenetic mechanisms and precautions for use in the therapeutic management of these patients. Better understanding of the complex phenomenon of the 'compensatory immunological switch', which TNF-α inhibitors and other biological drugs might trigger, can help not only appropriately managing immune-mediated disorders, but also better interpreting the heterogeneity of the pathogenetic mechanisms underlying certain chronic inflammatory conditions that, although different from each other, are arbitrarily placed in the context of overly generic nosological entities.

Familial Mediterranean Fever and Transverse Myelitis: A Causal Relation?

Familial Mediterranean fever (FMF) is a rare autoinflammatory disorder characterized mainly by recurrent self-limited episodes of fever and polyserositis. FMF-related neurologic complication is an old debate, and the correlation between FMF and demyelinating disorders has been a matter of dispute for a long time. Few reports demonstrated a relationship between FMF and multiple sclerosis; however, the existence of a causal relationship between FMF and demyelinating disorders is still a puzzle. This report presents the first case of transverse myelitis following FMF attacks in which neurologic manifestations were resolved using colchicine treatment. Due to relapses of FMF, which were accompanied by transverse myelitis, rituximab was administered, which resulted in stabilizing disease activity. Accordingly, in the case of colchicine-resistant FMF and FMF-related demyelinating conditions, rituximab could be considered as a potential therapeutic option to alleviate both polyserositis and demyelinating manifestations.

Precision nephrology: from molecular diagnostics to an individualized therapy

The diagnosis of glomerular disease still mostly relies on the conventional histologic and immunohistochemical analysis of biopsies, thereby failing to provide a molecular disease understanding and stratification as the fundamental basis for an individualized therapy. It is out of the question that nephrology will be transformed into a field of systemic molecular precision diagnostics and individualized therapies. However, the time scale and efficiency of such transformation will depend on more studies exemplifying successful translational strategies. The highly heterogeneous glomerular disease entities of minimal change disease and focal segmental glomerular sclerosis seem ideally suited to exploring and ensuring the advancement of an individualized precision nephrology.

Neurotherapeutic efficacy of loaded sulforaphane on iron oxide nanoparticles against cuprizone-induced neurotoxicity: role of MMP-9 and S100β

Cuprizone (CUP) induces neurotoxicity and demyelination in animal models by provoking the activation of glial cells and the generation of reactive oxygen species (ROS). Sulforaphane (SF) is a phytochemical that exhibits a neuroprotective potential. In this study, we investigated the neurotherapeutic and pro-remyelinating activities of SF and SF-loaded within iron oxide nanoparticles (IONP-SF) in CUP-exposed rats. Magnetite iron oxide nanoparticles (IONPs) were prepared using the hydrothermal method that was further loaded with SF (IONP-SF). The loading of SF within the magnetite nanoparticles was assessed using FTIR, TEM, DLS, Zetasizer, and XPS. For the in vivo investigations, adult male Wistar rats (n = 40) were administrated either on a regular diet or a diet with CUP (0.2%) for 5 weeks. The rats were divided into four groups: negative control, CUP-induced, CUP + SF, and CUP + IONP-SF. CUP-exposed brains exhibited a marked elevation in lipid peroxidation, along with a significant decrease in the activities of glutathione peroxidase (GPx), and catalase (CAT). In addition, CUP intoxication downregulated the expression of myelin basic protein (MBP) and myelin proteolipid protein (PLP), upregulated the expression of Matrix metallopeptidase-9 (MMP-9) and S100β, and increased caspase-3 immunoexpression, these results were supported histopathologically in the cerebral cortexes. Treatment of CUP-rats with either SF or IONP-SF demonstrated remyelinating and neurotherapeutic activities. We could conclude that IONP-SF was more effective than free SF in mitigating the CUP-induced downregulation of MBP, upregulation of S100β, and caspase-3 immunoexpression.

Multiple Sclerosis: Inflammatory and Neuroglial Aspects

Multiple sclerosis (MS) represents the most common acquired demyelinating disorder of the central nervous system (CNS). Its pathogenesis, in parallel with the well-established role of mechanisms pertaining to autoimmunity, involves several key functions of immune, glial and nerve cells. The disease's natural history is complex, heterogeneous and may evolve over a relapsing-remitting (RRMS) or progressive (PPMS/SPMS) course. Acute inflammation, driven by infiltration of peripheral cells in the CNS, is thought to be the most relevant process during the earliest phases and in RRMS, while disruption in glial and neural cells of pathways pertaining to energy metabolism, survival cascades, synaptic and ionic homeostasis are thought to be mostly relevant in long-standing disease, such as in progressive forms. In this complex scenario, many mechanisms originally thought to be distinctive of neurodegenerative disorders are being increasingly recognized as crucial from the beginning of the disease. The present review aims at highlighting mechanisms in common between MS, autoimmune diseases and biology of neurodegenerative disorders. In fact, there is an unmet need to explore new targets that might be involved as master regulators of autoimmunity, inflammation and survival of nerve cells.

Risk of Multiple Sclerosis Among Users of Antitumor Necrosis Factor α in 4 Canadian Provinces: A Population-Based Study

BACKGROUND AND OBJECTIVES

Antitumor necrosis factor α (TNFα) agents are a class of biologic drugs used for the treatment of several immune-mediated conditions. An increased risk of multiple sclerosis (MS) with their use has been suggested, but studies have been limited. Relevant population-based epidemiologic data linking anti-TNFα to MS are scarce. The objective was to compare the risk of MS in anti-TNFα users with nonusers among patients with rheumatic disease (RD) or inflammatory bowel disease (IBD).

METHODS

A nested case-control study was conducted. Population-based health care-linked databases from 4 Canadian provinces were used. All patients with RD or IBD residing within a participating province between January 2000 and March 2018 were identified by validated case definitions. Any anti-TNFα dispensation in the 2 years before the index date (MS onset) was identified. Incident onset MS cases were ascertained using a validated algorithm. Up to 5 controls were matched to each MS case based on birth year ±3 years, disease duration, and health authority (based on region of residence). Conditional logistic regressions were used to calculate the incidence rate ratio (IRR) after adjusting for potential confounders. A meta-analysis was conducted to provide pooled estimates across provinces using random-effects models.

RESULTS

Among 296,918 patients with RD patients, 462 MS cases (80.1% female, mean [SD] age, 47.4 [14.6] years) were matched with 2,296 controls (59.5% female, mean [SD] age, 47.4 [14.5] years). Exposure to anti-TNFα occurred in 18 MS cases and 42 controls. After adjusting for matching variables, sex, and the Charlson Comorbidity Index, the pooled IRR was 2.05 (95% CI, 1.13-3.72). Among 84,458 patients with IBD, 190 MS cases (69.5% female, mean [SD] age, 44.3 [12.3] years) were matched with 943 controls (54.1% female, mean [SD] age, 44.2 [12.2] years). Exposure to anti-TNFα occurred in 23 MS cases and 98 controls. The pooled adjusted IRR was 1.35 (95% CI, 0.70-2.59).

DISCUSSION

The use of anti-TNFα was associated with an increased risk of MS compared with nonusers, especially among patients with RD. These findings could help clinicians and patients with RD to make more informed treatment decisions. Further studies are needed to validate these results for patients with IBD.

Effect of Carvacrol on histological analysis and expression of genes involved in an animal model of multiple sclerosis

BACKGROUND

The most common non-traumatic neurological disease in young- and middle-aged adults is multiple sclerosis (MS), leading to central nervous system (CNS) atrophy and neurological disorders with loss of myelin and axonal degeneration. Due to the inadequate efficiency of common treatments, some natural products with antioxidant properties such as Carvacrol have been considered.

OBJECTIVE

the present study aimed to investigate carvacrol's anti-inflammatory and therapeutic effects on MS symptoms in healthy and experimental autoimmune encephalomyelitis (EAE) induced female Lewis rats.

METHODS

The study was performed in three groups of Lewis rats: control group, EAE model, and EAE treated with carvacrol (carvacrol-treated group). The treatment group received 25 mg/kg of carvacrol intraperitoneally daily. Histologic examination and expression analysis of pro-inflammatory genes (Interleukin-1 and 17 (IL-1 and IL-17), Nuclear Factor Kappa B Cells (NF-κB) and Tumor Necrosis Factor-α (TNF-α)), myelin repair, and also regeneration genes (Myelin basic protein (MBP), Oligodendrocyte Transcription Factor 2 (OLIG2) and Platelet-Derived Growth Factor Receptor α (PDGFR-α)) were carried out. Gene studies, Hematoxylin and Eosin (H&E), and Luxol fast blue stain were performed in the lumbar region of the spinal cord.

RESULTS

The EAE clinical scores in the carvacrol-treated group were lower than in untreated rats (P < 0.001). The expression of two genes, IL-17 and MBP, was confirmed using fluorescence immunohistochemistry (FIHC). A significant decrease was observed in NF-κB and IL-17, and IL-1 gene expression. The MBP and OLIG2 gene expression was increased in the carvacrol-treated group (p < 0.001). In EAE, PDGFR-α expression increased about four times. However, carvacrol administration did not affect PDGFR-α and TNF-α gene expression. In this treatment, H&E staining of spinal cord regions showed a significant decrease in inflammatory cell infiltration. Moreover, immunostaining analysis demonstrated a considerable increase in MBP and a reduction in IL-17 secretion.

CONCLUSION

The results showed that carvacrol administration reduces the entry of inflammatory cells into the CNS by stimulating myelination-related processes employing increasing the expression of genes involved in myelin repair and reducing the expression of inflammatory genes. Our findings confirm that carvacrol improves the clinical and pathological symptoms of EAE through its therapeutic and modification properties as a potential adjunctive therapy and needs to be studied more.

Exposure to specific tumour necrosis factor inhibitors and risk of demyelinating and inflammatory neuropathy in cohorts of patients with inflammatory arthritis: a collaborative observational study across five Nordic rheumatology registers

OBJECTIVE

To compare incidences of neuroinflammatory events, including demyelinating disease (DML), inflammatory polyneuropathies (IPN) and multiple sclerosis (MS), in patients with rheumatoid arthritis (RA) or spondyloarthritis (SpA; including psoriatic arthritis) starting a tumour necrosis factor inhibitor (TNFi), investigating whether monoclonal TNFi antibodies (other TNFis (oTNFis)) confer higher risk than etanercept.

METHODS

This is an observational cohort study including patients from the five Nordic countries starting a TNFi in 2001-2020. Time to first neuroinflammatory event was identified through register linkages. We calculated crude incidence rates (cIR) per 1000 person-years and used multivariable-adjusted Cox regression to compare incidences of neuroinflammatory events overall and for DML, IPN and MS with oTNFi versus etanercept. We further examined individual TNFis and indications.

RESULTS

33 883 patients with RA and 28 772 patients with SpA were included, initiating 52 704 and 46 572 treatment courses, respectively. In RA, we observed 135 neuroinflammatory events (65% DML) with cIR of 0.38 with oTNFi and 0.34 with etanercept. The HR of oTNFi versus etanercept was 1.07 (95% CI 0.74 to 1.54) for any neuroinflammatory event, 0.79 (95% CI 0.51 to 1.22) for DML, 2.20 (95% CI 1.05 to 4.63) for IPN and 0.73 (95% CI 0.34 to 1.56) for MS. In SpA, we observed 179 events (78% DML) with cIR of 0.68 with oTNFi and 0.65 with etanercept. The HR for any neuroinflammatory event, DML, IPN and MS was 1.06 (95% CI 0.75 to 1.50), 1.01 (95% CI 0.68 to 1.50), 1.28 (95% CI 0.61 to 2.69) and 0.94 (95% CI0.53 to 1.69), respectively.

CONCLUSION

The cIRs of neuroinflammatory events are higher in SpA than in RA, but the choice of specific TNFi does not seem to play an important role in the risk of neuroinflammatory events.

Role of imaging modalities and N-acetylcysteine treatment in sepsis-associated encephalopathy.. [DOI: 10.21203/rs.3.rs-2459747/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background Sepsis-associated encephalopathy is a severe complication due to systemic infection. Although early stages involve pathophysiological changes, detection using conventional imaging is challenging. Glutamate chemical exchange saturation transfer and diffusion kurtosis imaging can noninvasively investigate cellular and molecular events in the early stage of the disease by MRI. N-acetylcysteine, an antioxidant and precursor of glutathione, regulates the metabolism of the neurotransmitter glutamate and participates in neuroinflammation. We aimed to investigate the protective role of n-acetylcysteine in sepsis-associated encephalopathy using a rat model and monitor changes in the brain using magnetic resonance molecular imaging. Methods Bacterial lipopolysaccharide was injected intraperitoneally into the rats to induce a sepsis-associated encephalopathy model. The behavioural performance was assessed using the open field test. Tumour necrosis factor alpha and glutathione levels were detected biochemically. Imaging was performed using a 7.0-T MRI scanner. Protein expressions and cellular damage were assessed by western blotting and pathological staining, respectively. We also evaluated changes in the blood-brain barrier permeability by the Evans blue staining. Results The lipopolysaccharide-induced rats showed reduced anxiety and depression after treatment with n-acetylcysteine. Magnetic resonance molecular imaging can identify pathological processes at different stages of the disease. Furthermore, rats treated with n-acetylcysteine showed increased glutathione levels and decreased tumour necrosis factor alpha, suggesting enhanced antioxidant capacity and inhibition of inflammatory processes, respectively. Western blot analysis showed a reduced expression of nuclear factor kappa B (p50) protein after treatment, suggesting that n-acetylcysteine inhibits inflammation via this signalling pathway. Finally, n-acetylcysteine treated rats also showed reduced cellular damage by pathology and reduced extravasation of their blood-brain barrier by Evan Blue staining. Conclusion This study showed that n-acetylcysteine might be a therapeutic option for sepsis-associated encephalopathy and other neuroinflammatory diseases. Furthermore, non-invasive ‘dynamic visual monitoring’ of the physiological and pathological changes related to sepsis-associated encephalopathy was achieved for the first time using magnetic resonance molecular imaging, which provides a more sensitive imaging basis for early clinical diagnosis, identification, and prognosis.

Sixteen syndrome: a rare presentation of central demyelination

This case illustrates two diagnostic challenges for clinicians: the rarely described sixteen syndrome and the relationship between tumour necrosis factor (TNF)-alpha inhibitors and central demyelination. Sixteen syndrome affects horizontal eye movements and the facial nerve bilaterally reflecting a lesion in the posterior pontine tegmentum, adjacent to the fourth ventricle. Given its rarity and complexity of clinical signs, this syndrome risks misdiagnosis and mismanagement. The relationship between TNF-alpha inhibitors and demyelination is a complex issue in which causality is yet to be established. This diagnostic challenge poses a management dilemma for clinicians.

Treatment Options in Pediatric Behçet's Disease

Behçet's disease is a rare and poorly understood vasculitis affecting blood vessels of all types and sizes. Uveitis and oral and genital ulcers represent the typical clinical triad. Populations along the ancient trading route connecting the Mediterranean basin with the Middle and Far East are most affected. Up to a quarter of the cases has a pediatric onset, typically around puberty. The aim of the treatment is early intervention to control inflammation, with symptom relief and prevention of relapses, damage, and complications. The heterogeneous clinical presentation often requires a multidisciplinary and tailored approach. Ocular, neurological, gastrointestinal, and vascular involvement is associated with a worse prognosis and needs more aggressive treatments. In young patients with expected prolonged disease, treatment should also focus on preventive measures and lifestyle advice. In recent years, the pharmacological armamentarium has grown progressively, although only a limited number of drugs are currently authorized for pediatric use. Most evidence for these drugs still derives from adult studies and experience; these are prescribed as off-label medications and are only available as adult formulations. Corticosteroids frequently represent the mainstay for the management of the initial acute phases, but their potential serious adverse effects limit their use to short periods. Different conventional disease-modifying anti-rheumatic drugs have long been used. Many other biologic drugs targeting different cytokines such as interleukin-1, interleukin-6, and interleukin-17 and treatments with small molecules including the phosphodiesterase 4 and Janus kinase inhibitors are emerging as novel promising therapeutic agents. In recent years, a growing interest has developed around anti-tumor necrosis factor agents that have often proven to be effective in severe cases, especially in those with a gastrointestinal and ocular involvement.

Treatment of non-infectious retinal vasculitis

Retinal vasculitis (RV) refers to an entity in which the retinal vasculature is inflamed, frequently with indications of inflammation elsewhere in the eye. Non-infectious RV can be idiopathic or associated with systemic disease, ocular conditions, and malignancy. It can also be classified based on the vessel affected: artery, vein, or both. Due to the lack of strong evidence-based treatment trials and algorithms for RV, physicians must often rely on their experience, which creates great variability in treating this entity. This article provides an overview of various treatment modalities used in the management of non-infectious RV, with a focus on immunomodulatory therapies. We outline a potential stepwise approach of starting with steroids to control the acute inflammation and subsequently changing to immunomodulatory therapy (IMT) for long-term treatment.

Immunosuppressive biomaterial-based therapeutic vaccine to treat multiple sclerosis via re-establishing immune tolerance

Current therapies for autoimmune diseases, such as multiple sclerosis (MS), induce broad suppression of the immune system, potentially promoting opportunistic infections. Here, we report an immunosuppressive biomaterial-based therapeutic vaccine carrying self-antigen and tolerance-inducing inorganic nanoparticles to treat experimental autoimmune encephalomyelitis (EAE), a mouse model mimicking human MS. Immunization with self-antigen-loaded mesoporous nanoparticles generates Foxp3⁺ regulatory T-cells in spleen and systemic immune tolerance in EAE mice, reducing central nervous system-infiltrating antigen-presenting cells (APCs) and autoreactive CD4⁺ T-cells. Introducing reactive oxygen species (ROS)-scavenging cerium oxide nanoparticles (CeNP) to self-antigen-loaded nanovaccine additionally suppresses activation of APCs and enhances antigen-specific immune tolerance, inducing recovery in mice from complete paralysis at the late, chronic stage of EAE, which shows similarity to chronic human MS. This study clearly shows that the ROS-scavenging capability of catalytic inorganic nanoparticles could be utilized to enhance tolerogenic features in APCs, leading to antigen-specific immune tolerance, which could be exploited in treating MS.

The dichotomous outcomes of TNFα signaling in CD4+ T cells

TNFa blocking agents were the first-in-class biologic drugs used for the treatment of autoimmune disease. Paradoxically, however, exacerbation of autoimmunity was observed in some patients. TNFa is a pleiotropic cytokine that has both proinflammatory and regulatory effects on CD4+ T cells and can influence the adaptive immune response against autoantigens. Here, we critically appraise the literature and discuss the intricacies of TNFa signaling that may explain the controversial findings of previous studies. The pleiotropism of TNFa is based in part on the existence of two biologically active forms of TNFa, soluble and membrane-bound, with different affinities for two distinct TNF receptors, TNFR1 and TNFR2, leading to activation of diverse downstream molecular pathways involved in cell fate decisions and immune function. Distinct membrane expression patterns of TNF receptors by CD4+ T cell subsets and their preferential binding of distinct forms of TNFα produced by a diverse pool of cellular sources during different stages of an immune response are important determinants of the differential outcomes of TNFa-TNF receptor signaling. Targeted manipulation of TNFa-TNF receptor signaling on select CD4+ T cell subsets may offer specific therapeutic interventions to dampen inflammation while fortifying immune regulation for the treatment of autoimmune diseases.

Consequences of the Lack of TNFR1 in Ouabain Response in the Hippocampus of C57BL/6J Mice

Ouabain is a cardiac glycoside that has a protective effect against neuroinflammation at low doses through Na⁺/K⁺-ATPase signaling and that can activate tumor necrosis factor (TNF) in the brain. TNF plays an essential role in neuroinflammation and regulates glutamate receptors by acting on two different receptors (tumor necrosis factor receptor 1 [TNFR1] and TNFR2) that have distinct functions and expression. The activation of constitutively and ubiquitously expressed TNFR1 leads to the expression of pro-inflammatory cytokines. Thus, this study aimed to elucidate the effects of ouabain in a TNFR1 knockout (KO) mouse model. Interestingly, the hippocampus of TNFR1 KO mice showed a basal increase in both TNFR2 membrane expression and brain-derived neurotrophic factor (BDNF) release, suggesting a compensatory mechanism. Moreover, ouabain activated TNF-α-converting enzyme/a disintegrin and metalloprotease 17 (TACE/ADAM17), decreased N-methyl-D-aspartate (NMDA) receptor subunit 2A (NR2A) expression, and induced anxiety-like behavior in both genotype animals, independent of the presence of TNFR1. However, ouabain induced an increase in interleukin (IL)-1β in the hippocampus, a decrease in IL-6 in serum, and an increase in NMDA receptor subunit 1 (NR1) only in wild-type (WT) mice, indicating that TNFR1 or TNFR2 expression may be important for some effects of ouabain. Collectively, our results indicate a connection between ouabain signaling and TNFR1, with the effect of ouabain partially dependent on TNFR1.

Drug-related immune-mediated myelopathies

Iatrogenic immune-mediated inflammatory disorders of the spinal cord are an uncommon but potentially severe complication of drug therapy for several human diseases. Particularly the introduction of novel biological agents in the treatment of systemic inflammatory disorders and cancer immunotherapy have led to a significant increase in immune-related adverse events of the central nervous system (CNS). The use of Tumor necrosis factor alpha (TNF-alpha) inhibitors in rheumatic and inflammatory bowel diseases has been associated with demyelinating and other inflammatory CNS conditions, including myelitis. The introduction of immune checkpoint inhibitors in the treatment of several human malignancies has led to an increase in drug-induced immune-related adverse events including in the CNS. Other drugs that have been associated with immune-mediated myelitis include tyrosine-kinase inhibitors and chimeric antigen receptor (CAR) T Cell therapy. A high degree of suspicion is necessary when diagnosing these conditions, as early diagnosis and treatment is crucial in preventing further neurological damage and disability. The treatment of drug-induced inflammatory myelitis typically involves administration of high-dose intravenous corticosteroids, however additional immunosuppressive agents may be required in severe or refractory cases. While most cases are monophasic and remit following discontinuation of the offending agent, chronic immunosuppressive therapy may be indicated in cases with a progressive or relapsing disease course or when a diagnosis of a specific underlying neuro-inflammatory disorder is made. Outcomes are generally favorable, however depend on the specific therapeutic agent used, the clinical presentation and patient factors. In this review we aim to describe the clinical characteristics, imaging findings and management for the most common forms of iatrogenic immune-mediated myelopathies.

IL-6 and TNF-α responses to acute and regular exercise in adult individuals with multiple sclerosis (MS): a systematic review and meta-analysis

Background

In both the general population and people with multiple sclerosis (PwMS), physical exercise is associated with improved mental well-being. Moreover, there is evidence of the possible protection of physical activity against disease progression in multiple sclerosis (MS). However, the question arises if acute or regular exercise has any impact on the immune system in PwMS. To answer this question, we performed a systematic review and meta-analysis on both plasma and serum cytokine levels (IL-6 and TNF-α) before and after acute and regular exercise among PwMS and compared to healthy controls.

Method

We performed an online search via PubMed, EMBASE, SCOPUS, Web of Science, and Cochrane Library till September 2021 to identify original studies on IL-6 and TNF-α changes after acute and regular exercise in PwMS and controls. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), 11 original studies were included in the meta-analysis. Sensitivity analyses were used to identify the origins of heterogeneity. R 4.0.4 was used to perform the meta-analysis of IL-6 and TNF-α levels before and after acute and regular exercise in PwMS, compared to controls. This study does not qualify for a clinical trial number.

Results

IL-6 levels did neither increase nor decrease after acute and regular exercise in PwMS, and compared to controls (pre- vs. post-intervention: Standardized Mean Difference (SMD) -0.09, 95% CI [−0.29; 0.11], p-value = 0.37, PwMS vs. Control: SMD −0.08, 95% CI [−0.33; 0.16], p-value = 0.47). In PwMS, TNF-α levels decreased after regular exercise and when TNF-α levels of both acute and regular exercise were pooled (pre- vs. post-intervention: SMD −0.51, 95% CI [-0.91; 0.11], p-value = 0.01, PwMS vs. Control: SMD −0.23, 95% CI [−0.66; 0.18], p-value = 0.26). TNF-α levels did neither increase nor decrease after acute and regular exercise in PwMS, when compared to controls.

Conclusion

This systematic review and meta-analysis show that exercise does not lead to significant changes in peripheral levels of IL-6 in PwMS in contrast to the observed response in healthy subjects and other medical contexts. However, regular exercise had a specific anti-inflammatory effect on blood TNF-α levels in PwMS. It remains to be investigated why PwMS display this different exercise-induced pattern of cytokines.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00814-9.