Multiple Sclerosis and Autoimmunity: A Veiled Relationship

From Multiple Sclerosis to Organ-Specific Autoimmune Disorders: Insights into the Molecular and Clinical Implications of Comorbidity

Multiple sclerosis (MS) is a complex autoimmune disorder that affects the central nervous system. Although the pathological mechanisms of MS have been extensively studied, its association with other autoimmune diseases, known as comorbidities, remains unclear. In this comprehensive review article, we aim to clarify the cellular and molecular relationship between MS and the incidence of organ-specific autoimmune comorbidities by summarizing former studies. We will explore the commonalities and possible differences between the immune response mechanisms in MS and other autoimmune diseases and provide an overview of the current understanding of the pathophysiological processes involved in the co-occurrence of MS and other organ-specific autoimmune comorbidities. Through this review, we aim to contribute to the development of effective therapeutic strategies that can improve the quality of life of MS patients with comorbidities.

Autoimmune thyroiditis and its impact on the clinical course of Multiple Sclerosis: A retrospective cohort study

INTRODUCTION

Autoimmune thyroiditis (AT) stands out as one of the most prevalent accompanying comorbidity of Multiple Sclerosis (MS). However, the specific impact of AT on the clinical course of MS is relatively unexplored.

OBJECTIVES

The primary objective of this study is to determine the frequency of AT within an MS cohort and to assess its influence on the prognosis of MS.

METHOD

We retrospectively detected those who had an AT diagnosis during their lifetime. Patients who had been diagnosed with AT before a diagnosis of MS or during the diagnosis process were analyzed for prognosis. (aMS) Demographic variables, baseline Expanded Disability Status Scale (EDSS) score and relapse number, disease-modifying treatment duration and type, the relapse number, new/expanding lesions in brain and spinal MRI in first five years, fifth-year EDSS and fifth year No Evidence of Disease Activitiy-3 results were collected. These variables were compared to people with MS who had similar baseline and demographic characteristics. (non-AT) RESULTS: Fifty-seven people with MS (1.6 %) were diagnosed with AT, all of whom were female. Twenty-four of them were included in the prognosis analysis. There was no statistical difference between aMS and nonAT in diagnosis age, baseline relapse number and baseline EDSS score. (p > 0.05) There were no statistical differences in relapse number, MRI activity in five years, EDSS scores and NEDA-3 status in the fifth year. (P > 0.05) CONCLUSION: Comorbid AT is frequently seen in the MS population. It has a neutral effect on the MS course.

Comprehensive analysis of the global impact and distribution of tick paralysis, a deadly neurological yet fully reversible condition

SUMMARYTick paralysis is a potentially fatal condition caused by neurotoxins secreted by the salivary glands of certain ticks. Documented cases have been reported worldwide, predominantly in the United States, Canada, and Australia, with additional reports from Europe and Africa. This condition also affects animals, leading to significant economic losses and adverse impacts on animal health and welfare. To date, 75 tick species, mostly hard ticks, have been identified as capable of causing this life-threatening condition. Due to symptom overlap with other conditions, accurate diagnosis of tick paralysis is crucial to avoid misdiagnosis, which could result in adverse patient outcomes. This review provides a comprehensive analysis of the current literature on tick paralysis, including the implicated tick species, global distribution, tick toxins, molecular pathogenesis, clinical manifestations, diagnosis, treatment, control, and prevention. Enhancing awareness among medical and veterinary professionals is critical for improving the management of tick paralysis and its health impacts on both humans and animals.

A Hypoxia-Inflammation Cycle and Multiple Sclerosis: Mechanisms and Therapeutic Implications

Purpose of Review

Multiple sclerosis (MS) is a complex neurodegenerative disease characterized by inflammation, demyelination, and neurodegeneration. Significant hypoxia exists in brain of people with MS (pwMS), likely contributing to inflammatory, neurodegenerative, and vascular impairments. In this review, we explore the concept of a negative feedback loop between hypoxia and inflammation, discussing its potential role in disease progression based on evidence of hypoxia, and its implications for therapeutic targets.

Recent Findings

In the experimental autoimmune encephalomyelitis (EAE) model, hypoxia has been detected in gray matter (GM) using histological stains, susceptibility MRI and implanted oxygen sensitive probes. In pwMS, hypoxia has been quantified using near-infrared spectroscopy (NIRS) to measure cortical tissue oxygen saturation (StO2), as well as through blood-based biomarkers such as Glucose Transporter-1 (GLUT-1). We outline the potential for the hypoxia-inflammation cycle to drive tissue damage even in the absence of plaques. Inflammation can drive hypoxia through blood-brain barrier (BBB) disruption and edema, mitochondrial dysfunction, oxidative stress, vessel blockage and vascular abnormalities. The hypoxia can, in turn, drive more inflammation.

Summary

The hypoxia-inflammation cycle could exacerbate neuroinflammation and disease progression. We explore therapeutic approaches that target this cycle, providing information about potential treatments in MS. There are many therapeutic approaches that could block this cycle, including inhibiting hypoxia-inducible factor 1-α (HIF-1α), blocking cell adhesion or using vasodilators or oxygen, which could reduce either inflammation or hypoxia. This review highlights the potential significance of the hypoxia-inflammation pathway in MS and suggests strategies to break the cycle. Such treatments could improve quality of life or reduce rates of progression.

Prevalence of comorbid autoimmune diseases and antibodies in newly diagnosed multiple sclerosis patients

BACKGROUND

Diagnosing multiple sclerosis (MS) is challenging due to diverse symptoms and the absence of specific biomarkers. Concurrent autoimmune diseases (AID) or non-specific antibodies further complicate diagnosis, progression monitoring, and management. Data on AID prevalence in MS patients are sparse. This study aims to identify concurrent AIDs alongside MS.

METHODS

In this retrospective single-center study, we analyzed patient records at our university hospital from 2010 to 2017, focusing on cases suspected of inflammatory demyelinating disease. The 2017 McDonald criteria were applied. Additionally, we measured neurofilament light (NfL) levels from available CSF samples in our biobank.

RESULTS

We identified a total of 315 patients, of whom 66% were women. In total, 13.7% of all patients had concurrent AID, while 20.3% had isolated antibody findings without AID. The most common AID was autoimmune thyroiditis (8.9%), followed by chronic inflammatory skin diseases (1.6%), arthritis (1%), type 1 diabetes (1%), Sjögren's syndrome (0.6%), and inflammatory bowel diseases (0.6%). Cardiolipin antibodies were the most frequent isolated antibody finding (8.6%). Our data showed that, from the perspective of the initial demyelinating event, neither comorbid AID nor isolated antibodies significantly influenced relapses or MS progression over a median follow-up of 9 months. Standard CSF parameters and NfL levels were similar between the groups at the time of MS diagnosis.

CONCLUSION

Our study shows that AIDs, particularly autoimmune thyroiditis, frequently occur at the onset of MS. The proportion of AIDs commonly treated with immunomodulatory therapy in our cohort was similar to that observed in the general population. Comorbid AID did not affect NfL levels, indicating similar disease activity. Future research should explore new AID emergence during the course of MS, especially considering the increased incidence of rheumatic diseases later in life.

The Role of Sex and Other Personal Characteristics in the Effects of Symptoms Severity on Self-Care Agency in Individuals with Multiple Sclerosis

BACKGROUND

Multiple sclerosis (MS) is a chronic, autoimmune disease that attacks the central nervous system.

AIMS

The study was conducted to determine the role of sex and other personal characteristics in the impact of symptom severity on self-care in individuals with MS.

METHODS

The study was cross-sectional and was completed with 200 participants throughout Turkey. The data were collected through random and snowball sampling using the MS-related symptom checklist (MS-RS), the Fatigue Severity Scale (FSS), and the Exercise of Self-Care Agency (ESCA) form. The data obtained were analyzed using the SPSS 21. Statistical significance was evaluated at the level of p < 0.05.

RESULTS

The mean age of the participants was 37.97 ± 10.6 years. The mean scores were 47.4 ± 22.41 for MS-RS, 4.58 ± 2.2 for FSS, and 94.65 ± 24.76 for ESCA in females. The mean MS-RS score in males was 45 ± 25.89, FSS was 4.33 ± 2.5, and ESCA was 83.43 ± 23.95. There were no significant differences between the sexes except that the ESCA scores were higher in females (p < 0.05). According to a multiple linear regression analysis, the duration of diagnosis and sensory subdimension of MS-RS negatively affected the ESCA score in females, and this statistically significant model explained 22.6% of ESCA scores.

CONCLUSION

The study found that both sexes had clinically significant fatigue, mildly severe symptoms, and moderate self-care agency. While being a female positively affected self-care agency, disease duration, and sensory symptoms negatively affected females' self-care agency.

Mitophagy and cGAS-STING crosstalk in neuroinflammation

Mitophagy, essential for mitochondrial health, selectively degrades damaged mitochondria. It is intricately linked to the cGAS-STING pathway, which is crucial for innate immunity. This pathway responds to mitochondrial DNA and is associated with cellular stress response. Our review explores the molecular details and regulatory mechanisms of mitophagy and the cGAS-STING pathway. We critically evaluate the literature demonstrating how dysfunctional mitophagy leads to neuroinflammatory conditions, primarily through the accumulation of damaged mitochondria, which activates the cGAS-STING pathway. This activation prompts the production of pro-inflammatory cytokines, exacerbating neuroinflammation. This review emphasizes the interaction between mitophagy and the cGAS-STING pathways. Effective mitophagy may suppress the cGAS-STING pathway, offering protection against neuroinflammation. Conversely, impaired mitophagy may activate the cGAS-STING pathway, leading to chronic neuroinflammation. Additionally, we explored how this interaction influences neurodegenerative disorders, suggesting a common mechanism underlying these diseases. In conclusion, there is a need for additional targeted research to unravel the complexities of mitophagy-cGAS-STING interactions and their role in neurodegeneration. This review highlights potential therapies targeting these pathways, potentially leading to new treatments for neuroinflammatory and neurodegenerative conditions. This synthesis enhances our understanding of the cellular and molecular foundations of neuroinflammation and opens new therapeutic avenues for neurodegenerative disease research.

Mathematical modeling in autoimmune diseases: from theory to clinical application

The research & development (R&D) of novel therapeutic agents for the treatment of autoimmune diseases is challenged by highly complex pathogenesis and multiple etiologies of these conditions. The number of targeted therapies available on the market is limited, whereas the prevalence of autoimmune conditions in the global population continues to rise. Mathematical modeling of biological systems is an essential tool which may be applied in support of decision-making across R&D drug programs to improve the probability of success in the development of novel medicines. Over the past decades, multiple models of autoimmune diseases have been developed. Models differ in the spectra of quantitative data used in their development and mathematical methods, as well as in the level of "mechanistic granularity" chosen to describe the underlying biology. Yet, all models strive towards the same goal: to quantitatively describe various aspects of the immune response. The aim of this review was to conduct a systematic review and analysis of mathematical models of autoimmune diseases focused on the mechanistic description of the immune system, to consolidate existing quantitative knowledge on autoimmune processes, and to outline potential directions of interest for future model-based analyses. Following a systematic literature review, 38 models describing the onset, progression, and/or the effect of treatment in 13 systemic and organ-specific autoimmune conditions were identified, most models developed for inflammatory bowel disease, multiple sclerosis, and lupus (5 models each). ≥70% of the models were developed as nonlinear systems of ordinary differential equations, others - as partial differential equations, integro-differential equations, Boolean networks, or probabilistic models. Despite covering a relatively wide range of diseases, most models described the same components of the immune system, such as T-cell response, cytokine influence, or the involvement of macrophages in autoimmune processes. All models were thoroughly analyzed with an emphasis on assumptions, limitations, and their potential applications in the development of novel medicines.

Volumetric and Asymmetric Index Analysis of Subcortical Structures in Multiple Sclerosis Patients: A Retrospective Study Using volBrain Software

Introduction Multiple sclerosis (MS) is a chronic and autoimmune disease that has a significant influence on the central nervous system, such as the brain and spinal cord, affecting millions of individuals globally. Understanding the connection between subcortical brain regions and MS is crucial for effective diagnostic and therapeutic approaches for treating this disabling disease. This study explores the relationship between volume and contours of asymmetry index of subcortical brain regions in individuals with MS using volBrain software (https://www.volbrain.net; developed by José V. Manjón (Valencia Polytechnic University, Valencia, Spain) and Pierrick Coupé (University of Bordeaux, Bordeaux, France)). Methods In our retrospective investigation, we admitted 100 Turkish individuals, comprising 50 patients diagnosed with relapsing-remitting MS (RRMS) (24 (48%) males and 26 (52%) females) and 50 healthy controls (23 (46%) males and 27 (54%) females), registered between October 2017 and February 2022 for five years and underwent assessment in the radiology department at the Teaching and Research Hospital of Kocaeli University; 1,150 Turkish patients were excluded from our study based on our exclusion criteria. We used magnetic resonance imaging with a 3-Tesla (3T) scanner and volBrain software to assess volumes (cm3) and asymmetry indexes due to asymmetry for different levels of atrophy of total intracranial, total brain, gray matter, white matter, and subcortical regions, the most affected regions in MS patients for both patient and control cohorts. Results Statistical analysis revealed a significant difference between patient and control groups (p < 0.001), with patient group mean age at 38.32 years and control group mean age at 32.88 years. Patient group exhibited lower values for total intracranial, total brain, gray matter, white matter, and cerebrospinal fluid volume compared to control group (p < 0.05). The results indicated a statistically significant decrease (p < 0.05) in the values for total intracranial and total brain volume, whereas all other values remained unchanged. We compared volumes of subcortical structures on the right and left sides and found that the putamen, thalamus, and globus pallidus had statistically lower values in the patient group than in the control group (p < 0.001), apart from the lateral ventricle. Furthermore, our retrospective investigation demonstrated a statistically significant difference in the globus pallidus asymmetry index, indicating a preference for the patient group (p < 0.05). A lower asymmetry index value signifies a larger volume for the right side of the subcortical regions of the brain when compared to the left side. Conclusion Brain atrophy, although characterized by irreversible tissue damage, is targeted by therapeutic interventions to prevent progression. It is, therefore, imperative to develop a universally accepted measurement standard for subcortical structures that also considers the inherent variability present within each structure. Our findings serve as an important basis and indicator for the determination of subcortical atrophy and asymmetry in MS, the prognosis of the disease, and the etiology of clinical symptoms. Subsequent research may benefit by adopting the novel approach of considering brain atrophy as an outcome rather than a predictor, thereby facilitating the elucidation of the intricate biological mechanisms that give rise to volume loss.

The toxic metal hypothesis for neurological disorders

Multiple sclerosis and the major sporadic neurogenerative disorders, amyotrophic lateral sclerosis, Parkinson disease, and Alzheimer disease are considered to have both genetic and environmental components. Advances have been made in finding genetic predispositions to these disorders, but it has been difficult to pin down environmental agents that trigger them. Environmental toxic metals have been implicated in neurological disorders, since human exposure to toxic metals is common from anthropogenic and natural sources, and toxic metals have damaging properties that are suspected to underlie many of these disorders. Questions remain, however, as to how toxic metals enter the nervous system, if one or combinations of metals are sufficient to precipitate disease, and how toxic metal exposure results in different patterns of neuronal and white matter loss. The hypothesis presented here is that damage to selective locus ceruleus neurons from toxic metals causes dysfunction of the blood-brain barrier. This allows circulating toxicants to enter astrocytes, from where they are transferred to, and damage, oligodendrocytes, and neurons. The type of neurological disorder that arises depends on (i) which locus ceruleus neurons are damaged, (ii) genetic variants that give rise to susceptibility to toxic metal uptake, cytotoxicity, or clearance, (iii) the age, frequency, and duration of toxicant exposure, and (iv) the uptake of various mixtures of toxic metals. Evidence supporting this hypothesis is presented, concentrating on studies that have examined the distribution of toxic metals in the human nervous system. Clinicopathological features shared between neurological disorders are listed that can be linked to toxic metals. Details are provided on how the hypothesis applies to multiple sclerosis and the major neurodegenerative disorders. Further avenues to explore the toxic metal hypothesis for neurological disorders are suggested. In conclusion, environmental toxic metals may play a part in several common neurological disorders. While further evidence to support this hypothesis is needed, to protect the nervous system it would be prudent to take steps to reduce environmental toxic metal pollution from industrial, mining, and manufacturing sources, and from the burning of fossil fuels.