Hypersensitivity Responses in the Central Nervous System

Experiences of integrating and sustaining physical activity in life with multiple sclerosis, Alzheimer's disease, and ischaemic heart disease: a scoping review

PURPOSE

The effects of physical activity on health are well-established for chronic diseases such as multiple sclerosis (MS), Alzheimer's disease (AD), and ischaemic heart disease (IHD). However, sustaining physical activity in everyday life is difficult. Lifeworld knowledge can help qualify interventions aimed at resolving this public health issue, but there is a gap in regard to synthesized research on peoples' experiences with integrating and sustaining physical activity. Hence, the purpose of this review is to explore and present the available evidence on experiences with integrating and sustaining physical activity in a lived life with MS, AD, and IHD.

METHODS

We conducted a scoping review with qualitative analysis and narrative syntheses in accordance with PRISMA-ScR. Based on SPIDER we ran a systematic search in Cinahl, Embase, Medline, and PsychInfo for primary qualitative research papers published until December 2022.

RESULTS

43 papers were included. A thematic content analysis found that individuals who have MS, AD or IHD find integrating and sustaining physical activity in everyday life meaningful on several levels: Physical activity can facilitate meaningful movement with outcomes of physical, psychosocial, and existential importance.

CONCLUSION

The research literature presents a meaning to physical activity that extends the idea of physical fitness to one of existential movement and personal growth. In addition, our review finds that people are more likely to integrate and sustain physical activity if they feel acknowledged, supported and believe that physical activity has a meaningful purpose reflecting their sense of self. Taking a more person-centred approach in rehabilitative care might help qualify the content of physical activity in terms of integration into everyday life, but more research is needed on how to implement a person-centred approach in practice.

Helicobacter pylori infection and risk of multiple sclerosis: an updated meta-analysis

Numerous studies have proposed that Helicobacter pylori infection may possess a protective effect in terms of future risk of multiple sclerosis (MS), however is poorly evidenced. We performed a systematic review and meta-analysis to obtain the pooled results regarding the prevalence of H. pylori infection in persons with multiple sclerosis (pwMS) and healthy controls. A comprehensive database search was performed in PubMed, Embase, and medRxiv for all relevant literature published from the inception of the databases until the August 1, 2022. The retrieved articles were first screened by title and abstract, followed by full-text screening based on the pre-established eligibility criteria. The risk of bias was assessed using the ROBINS-I tool. Data on the seroprevalence of H. pylori in pwMS and healthy controls was extracted, and a meta-analysis was performed in Review Manager Version 5.4.1. Sub-group analysis was performed in accordance with the geographical distribution (Eastern and Western countries) and the method of detection of H. pylori infection enzyme-linked-immunoassay (ELISA), Immunofluorescence, Immunochromatography). Furthermore, sensitivity analyses and publication bias were determined. The preliminary database search retrieved a total of 822 studies. Seventeen case-control studies with a total of 2721 pwMS and 2245 controls were included as a final sample size for the meta-analysis. The overall risk of bias was moderate. Overall, the rate of H. pylori infection in pwMS was not significantly different than in healthy controls (OR: 0.79 (95% CI = 0.58-1.08); I2 = 79%, p = 0.14). Subgroup analysis revealed that the rate of H. pylori infection among PwMS was not significant in both Eastern and Western countries (OR: 0.75 (95% CI = 0.52-1.08); I2 = 81%, p = 0.12). In contrast, data revealed that the prevalence of H. pylori infection in pwMS was significantly lower than that of control based on studies utilizing ELISA assays detection (OR: 0.71 (95% CI = 0.50-1.00); I2 = 81%, p = 0.05), while no significant difference was seen on studies using other assays than ELISA (OR: 1.19 (95% CI = 0.81-1.77); I2 = 0%, p = 0.38). Our findings of statistically indifferent prevalence of H. pylori infection as compared between pwMS and healthy controls suggested the absence of protective effect for risk of MS following H. pylori infection.

Concordance rate between oligoclonal bands and the Kappa index in patients with suspected multiple sclerosis (MS)

BACKGROUND

 Oligoclonal bands (OCBs) and Kappa free light chains (FLCs) in the cerebrospinal fluid (CSF) are sensitive markers of intrathecal immunoglobulin (Ig)G synthesis in patients with multiple sclerosis.

OBJECTIVE

 To evaluate the concordance rate between OCBCs and the Kappa index (KI) in patients with suspected multiple sclerosis (MS).

METHODS

 Patients with suspected MS were referred to a specialized CSF laboratory as part of their diagnostic investigation. Paired CSF and serum samples were collected and submitted to detection of OCBs and determination of the KI. Positive and negative results were determined with both methods, and the percentage of agreement between them was established.

RESULTS

 In total, 171 serum and CSF samples from 171 patients were included in the analysis. The mean age of the patients was of 40 ± 14.2 years; 18.9% of them were male, and 81.1% were female. The OCBs and KI presented concordant results in 161 (94.2%) samples: in 74 (43.3%), both were positive, and in 87 (50.9%), both were negative. In 10 cases, the results were discrepant: KI positive/OCB negative in 8 and OCB positive/KI negative in 2 cases.

CONCLUSION

 The KI and OCBs presented high concordance level. Currently, the detection of OCBs in the CSF is the standard method for MS diagnosis, but it is time-consuming, and its visual interpretation can be difficult. The results suggest that the KI is a good alternative for the detection of intrathecal immunoproduction in cases of suspected MS.

Cross-Linking Cellular Prion Protein Induces Neuronal Type 2-Like Hypersensitivity

Background

Previous reports identified proteins associated with ‘apoptosis’ following cross-linking PrP^C with motif-specific anti-PrP antibodies in vivo and in vitro. The molecular mechanisms underlying this IgG-mediated neurotoxicity and the role of the activated proteins in the apoptotic pathways leading to neuronal death has not been properly defined. Previous reports implicated a number of proteins, including apolipoprotein E, cytoplasmic phospholipase A2, prostaglandin and calpain with anti-PrP antibody-mediated ‘apoptosis’, however, these proteins are also known to play an important role in allergy. In this study, we investigated whether cross-linking PrP^C with anti-PrP antibodies stimulates a neuronal allergenic response.

Methods

Initially, we predicted the allergenicity of the epitope sequences associated with ‘neurotoxic’ anti-PrP antibodies using allergenicity prediction servers. We then investigated whether anti-PrP antibody treatment of mouse primary neurons (MPN), neuroblastoma cells (N2a) and microglia (N11) cell lines lead to a neuronal allergenic response.

Results

In-Silico studies showed that both tail- and globular-epitopes were allergenic. Specifically, binding regions that contain epitopes for previously reported ‘neurotoxic’ antibodies such as ICSM18 (146-159), ICSM35 (91-110), POM 1 (138-147) and POM 3 (95-100) lead to activation of allergenic related proteins. Following direct application of anti-PrP^C antibodies on N2a cells, we identified 4 neuronal allergenic-related proteins when compared with untreated cells. Furthermore, we identified 8 neuronal allergenic-related proteins following treatment of N11 cells with anti-PrP^C antibodies prior to co-culture with N2a cells when compared with untreated cells. Antibody treatment of MPN or MPN co-cultured with antibody-treated N11 led to identifying 10 and 7 allergenic-related proteins when compared with untreated cells. However, comparison with 3F4 antibody treatment revealed 5 and 4 allergenic-related proteins respectively. Of importance, we showed that the allergenic effects triggered by the anti-PrP antibodies were more potent when antibody-treated microglia were co-cultured with the neuroblastoma cell line. Finally, co-culture of N2a or MPN with N11-treated with anti-PrP antibodies resulted in significant accumulation of NO and IL6 but not TNF-α in the cell culture media supernatant.

Conclusions

This study showed for the first time that anti-PrP antibody binding to PrP^C triggers a neuronal hypersensitivity response and highlights the important role of microglia in triggering an IgG-mediated neuronal hypersensitivity response. Moreover, this study provides an important impetus for including allergenic assessment of therapeutic antibodies for neurodegenerative disorders to derive safe and targeted biotherapeutics.

Genetics of psychic ability - A pilot case-control exome sequencing study

INTRODUCTION

It is commonly believed that psychic ability, like many mental and physical traits, runs in families. This suggests the presence of a genetic component. If such a component were found, it would constitute a biological marker of psychic ability and inform environmental or pharmacologic means of enhancing or suppressing this ability.

METHODS

A case-control study design was used to evaluate differences between psychic cases and non-psychic controls. Over 3,000 candidates globally were screened through two online surveys to locate people who claimed they and other family members were psychic. Measures of relevance to the claimed abilities (e.g., absorption, empathy, schizotypy) were collected and based on those responses, individuals with indications of psychotic or delusional tendencies were excluded from further consideration. Eligible candidates were then interviewed and completed additional screening tests. Thirteen individuals were selected as the final "psychic cases," and ten age-, sex-, and ethnicity-matched individuals with no claims of psychic ability were selected as controls. DNA from the saliva of these 23 participants was subjected to whole-exome sequencing. Two independent bioinformatics analyses were blindly applied to the sequenced data, one focusing exclusively on protein-coding sequences and another that also included some adjacent noncoding sequences.

RESULTS

Sequencing data were obtained for all samples, except for one in the control group that did not pass the quality controls and was not included in further analyses. After unblinding the datasets, none of the protein-coding sequences (i.e., exons) showed any variation that discriminated between cases and controls. However, a difference was observed in the intron (i.e., non-protein-coding region) adjacent to an exon in the TNRC18 gene (Trinucleotide Repeat-Containing Gene 18 Protein) on chromosome 7. This variation, an alteration of GG to GA, was found in 7 of 9 controls and was absent from all psychic cases.

DISCUSSION

The most conservative interpretation of these results is that they result from random population sampling. However, when the results are considered in relation to other lines of evidence, the results are more provocative. Further research is justified to replicate and extend these findings.

The CSF Levels of Neutrophil-Related Chemokines in Patients with Neuromyelitis Optica

Pathologic findings showed that neutrophils played an important role in the pathogenesis of NMO. This study aims to investigate the CSF levels of neutrophil‐related chemokines in NMO. CXCL1, CXCL5, and CXCL7 were measured in 95 patients with NMO, 15 patients with MS, 18 patients with GFAP astrocytopathy, and 16 controls. The CSF level of CXCL1, CXCL5, and CXCL7 was significantly elevated in the NMO group but not correlated with the patient clinical severity. Besides, the CSF CXCL1, CXCL5, and CXCL7 could act as biomarkers to distinguish NMO from MS with good reliability, especially the CXCL7.

Neuroimmune Axes of the Blood-Brain Barriers and Blood-Brain Interfaces: Bases for Physiological Regulation, Disease States, and Pharmacological Interventions

Central nervous system (CNS) barriers predominantly mediate the immune-privileged status of the brain, and are also important regulators of neuroimmune communication. It is increasingly appreciated that communication between the brain and immune system contributes to physiologic processes, adaptive responses, and disease states. In this review, we discuss the highly specialized features of brain barriers that regulate neuroimmune communication in health and disease. In section I, we discuss the concept of immune privilege, provide working definitions of brain barriers, and outline the historical work that contributed to the understanding of CNS barrier functions. In section II, we discuss the unique anatomic, cellular, and molecular characteristics of the vascular blood-brain barrier (BBB), blood-cerebrospinal fluid barrier, and tanycytic barriers that confer their functions as neuroimmune interfaces. In section III, we consider BBB-mediated neuroimmune functions and interactions categorized as five neuroimmune axes: disruption, responses to immune stimuli, uptake and transport of immunoactive substances, immune cell trafficking, and secretions of immunoactive substances. In section IV, we discuss neuroimmune functions of CNS barriers in physiologic and disease states, as well as pharmacological interventions for CNS diseases. Throughout this review, we highlight many recent advances that have contributed to the modern understanding of CNS barriers and their interface functions.