Treatment for Rheumatoid Arthritis and Risk of Alzheimer's Disease: A Nested Case-Control Analysis

Development of potent humanized TNFα inhibitory nanobodies for therapeutic applications in TNFα-mediated diseases

Tumor necrosis factor-alpha (TNFα) is a key pro-inflammatory cytokine implicated in the pathogenesis of numerous inflammatory and autoimmune diseases, including rheumatoid arthritis, inflammatory bowel disease, and neurodegenerative disorders such as Alzheimer's disease. Effective inhibition of TNFα is essential for mitigating disease progression and improving patient outcomes. In this study, we present the development and comprehensive characterization of potent humanized TNFα inhibitory nanobodies (TNFI-Nbs) derived from camelid single-domain antibodies. In silico analysis of the original camelid nanobodies revealed low immunogenicity, which was further reduced through machine learning-guided humanization and developability optimization. The two humanized TNFI-Nb variants we developed demonstrated high anti-TNFα activity, achieving IC₅₀ values in the picomolar range. Binding assays confirmed their high affinity for TNFα, underscoring robust neutralization capabilities. These TNFI-Nbs present valid alternatives to conventional monoclonal antibodies currently used in human therapy, offering potential advantages in potency, specificity, and reduced immunogenicity. Our findings establish a solid foundation for further preclinical development and clinical translation of TNFα-targeted nanobody therapies in TNFα-mediated diseases.

Dementia Risk in Psoriasis Patients Treated with Biologics: A Propensity Score-matched Population-based Cohort Study

Translational research and animal models suggest that psoriasis treatments may have neuroprotective effects and reduce dementia risk. This study evaluates the association between biologic therapies for psoriasis and dementia incidence. A retrospective cohort included patients aged 65 or older with psoriasis, divided into 2 groups: those receiving biologic therapy following systemic treatment and those on systemic treatment alone. Patients with prior dementia were excluded. Dementia diagnosis was assessed at least 12 months after biologic initiation. Propensity score matching yielded 1,766 patients (883 per group). Biologic therapy was associated with a 53% reduced dementia risk (hazard ratio 0.47, 95% confidence interval 0.323-0.699), supported by a multivariate Cox model (adjusted hazard ratio 0.52, 95% confidence interval 0.392-0.699). These findings suggest that biologic therapies targeting tumour necrosis factor-alpha, interleukin-17, and interleukin-23 may reduce the risk of dementia, even after adjusting for age and other confounders.

Impact of TNF inhibitors on inflammation-associated cognitive dysfunction in patients with rheumatoid arthritis: a prospective analysis

Objectives

To evaluate cognitive improvement in patients with rheumatoid arthritis (RA) after 6 months of treatment with tumor necrosis factor (TNF) inhibitors, analyze associated factors, and determine the percentage of patients achieving cognitive improvement.

Methods

This was a single-center prospective observational study conducted over 12 months on 70 RA patients initiating their first biologic disease-modifying antirheumatic drug (bDMARD) with a TNF inhibitor. Cognitive function was assessed at baseline and after 6 months using validated neuropsychological tests, including the Montreal Cognitive Assessment (MoCA) for global cognitive function, the digit span forward and backward tests for attention and working memory, and the Stroop-W, Stroop-C, and Stroop-CW tests for executive function and processing speed. Patient-reported outcomes were assessed using the Hospital Anxiety and Depression Scale (HADS) and the Quality of Life-Rheumatoid Arthritis Scale-II (QOL-RA II). Clinical variables, disease activity measured by the 28-joint Disease Activity Score based on C-reactive protein (DAS28-CRP), inflammatory markers including C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), and patient-reported outcomes were recorded. Associations with average CRP and Health Assessment Questionnaire (HAQ) scores were analyzed throughout the follow-up period. Cognitive improvement was defined as a ≥20% increase in MoCA test scores. Logistic regression was performed to identify factors associated with improvement.

Results

A total of 70 patients (mean age, 56.2 years; 81.4% female) were included. After 6 months, patients showed significant cognitive improvement in a validated questionnaire, namely, the Montreal Cognitive Assessment (MoCA test 23.1 ± 3.6 to 24.1 ± 3.3; p = 0.001), particularly in the executive and memory domains. Significant improvements were also observed in the digit span forward test (p = 0.003), digit span backward test (p = 0.021), Stroop-W test (p = 0.040), Stroop-C test (p = 0.014), and Stroop-CW test (p = 0.035). Improvements in the MoCA were associated with educational level (B = 2.628; p < 0.001), average CRP (B = -0.154; p = 0.002), and average HAQ (B = -0.303; p = 0.022). Similar associations were found for the other tests.

Conclusion

TNF inhibitor therapy in RA patients is associated with significant cognitive improvement, particularly in executive function and memory. These findings highlight the potential cognitive benefits of effective RA treatment and underscore the importance of addressing modifiable risk factors to enhance patient quality of life.

Impact of Disease-Modifying Antirheumatic Drugs on Cognitive Function in Older Adults with Rheumatoid Arthritis

Cognitive impairment poses significant challenges for aging populations. Systemic inflammation, a hallmark of rheumatoid arthritis (RA), has been implicated in neurodegeneration through mechanisms including blood-brain barrier disruption, microglial activation, and cytokine-mediated neuronal damage. This review examines the potential impact of disease-modifying antirheumatic drugs (DMARDs) on cognitive function in RA, focusing on the inflammatory pathways linking systemic inflammation to neuroinflammation and cognitive decline. DMARDs, categorized into conventional synthetic (csDMARDs), biologic (bDMARDs), and targeted synthetic (tsDMARDs) classes, modulate immune responses through distinct mechanisms. Evidence suggests that DMARDs, particularly bDMARDs targeting proinflammatory cytokines such as TNF-α and IL-6, may mitigate neuroinflammatory processes and preserve cognitive function. However, the cognitive impact of csDMARDs such as methotrexate is complex, with conflicting reports regarding its role in vascular dementia. Emerging therapies such as Janus kinase inhibitors (JAK-i) offer promise in modulating central inflammation, though clinical evidence remains limited. While some studies highlight protective effects of DMARDs against dementia, findings are inconsistent, hindered by heterogeneity in study design, patient demographics, and cognitive assessment methods. This review underscores the need for personalized treatment strategies, integrating RA management with cognitive health considerations. Future research should prioritize robust, prospective studies with long-term follow-up, incorporating neuroimaging and biomarker analysis to elucidate the mechanisms underpinning DMARD-associated cognitive outcomes. A better understanding of the involved inflammatory pathways in RA and the potential effects of DMARDs could lead to improved therapeutic approaches, enhancing quality of life for patients with RA and potentially benefiting broader strategies in preventing or treating dementia.

Immune modulation to treat Alzheimer's disease

Immune mechanisms play a fundamental role in Alzheimer's disease (AD) pathogenesis, suggesting that approaches which target immune cells and immunologically relevant molecules can offer therapeutic opportunities beyond the recently approved amyloid beta monoclonal therapies. In this review, we provide an overview of immunomodulatory therapeutics in development, including their preclinical evidence and clinical trial results. Along with detailing immune processes involved in AD pathogenesis and highlighting how these mechanisms can be therapeutically targeted to modify disease progression, we summarize knowledge gained from previous trials of immune-based interventions, and provide a series of recommendations for the development of future immunomodulatory therapeutics to treat AD.

Blood inflammation relates to neuroinflammation and survival in frontotemporal lobar degeneration

Neuroinflammation is an important pathogenic mechanism in many neurodegenerative diseases, including those caused by frontotemporal lobar degeneration. Post-mortem and in vivo imaging studies have shown brain inflammation early in these conditions, proportional to symptom severity and rate of progression. However, evidence for corresponding blood markers of inflammation and their relationships to central inflammation and clinical outcome are limited. There is a pressing need for such scalable, accessible and mechanistically relevant blood markers because these will reduce the time, risk and costs of experimental medicine trials. We therefore assessed inflammatory patterns of serum cytokines from 214 patients with clinical syndromes associated with frontotemporal lobar degeneration in comparison to healthy controls, including their correlation with brain regional microglial activation and disease progression. Serum assays used the MesoScale Discovery V-Plex-Human Cytokine 36 plex panel plus five additional cytokine assays. A subgroup of patients underwent 11C-PK11195 mitochondrial translocator protein PET imaging, as an index of microglial activation. A principal component analysis was used to reduce the dimensionality of cytokine data, excluding cytokines that were undetectable in >50% of participants. Frequentist and Bayesian analyses were performed on the principal components to compare each patient cohort with controls and test for associations with central inflammation, neurodegeneration-related plasma markers and survival. The first component identified by the principal component analysis (explaining 21.5% variance) was strongly loaded by pro-inflammatory cytokines, including TNF-α, TNF-R1, M-CSF, IL-17A, IL-12, IP-10 and IL-6. Individual scores of the component showed significant differences between each patient cohort and controls. The degree to which a patient expressed this peripheral inflammatory profile at baseline was correlated negatively with survival (higher inflammation, shorter survival), even when correcting for baseline clinical severity. Higher pro-inflammatory profile scores were associated with higher microglial activation in frontal and brainstem regions, as quantified with 11C-PK11195 mitochondrial translocator protein PET. A permutation-based canonical correlation analysis confirmed the association between the same cytokine-derived pattern and central inflammation across brain regions in a fully data-based manner. This data-driven approach identified a pro-inflammatory profile across the frontotemporal lobar degeneration clinical spectrum, which is associated with central neuroinflammation and worse clinical outcome. Blood-based markers of inflammation could increase the scalability and access to neuroinflammatory assessment of people with dementia, to facilitate clinical trials and experimental medicine studies.

Drug-induced dementia: a real-world pharmacovigilance study using the FDA Adverse Event Reporting System database

Background

Dementia is a serious adverse event (AE) that requires attention in clinical practice. However, information on drug-induced dementia is limited. The U.S. FDA Adverse Event Reporting System (FAERS) serves as an important resource for identifying real-world adverse drug reactions and safety signals.

Objective

This study aimed to use FAERS data to identify drugs associated with increased dementia risk.

Design

A secondary analysis of the FAERS database was conducted using disproportionality analysis methods.

Methods

We reviewed dementia-related reports in the FAERS database from the first quarter of 2004 to the fourth quarter of 2023, used the Medical Dictionary for Regulatory Activity to identify dementia cases and summarized the corresponding list of potential medications, counted the dementia-causing medication classes with the highest frequency of reports, and disaggregated all medications.

Results

The study identified 31,881 dementia-related AEs in the FAERS database, with an increasing trend over time, particularly among females and individuals over 65. Apixaban had the most reports (1631). Disproportionality analyses revealed that rivastigmine, nicergoline, aducanumab, amlodipine/atorvastatin, and dihydroergometrine had the highest risk, based on reporting odds ratio, proportional reporting ratio, and information component. Only valproate and tramadol among the top 50 drugs included a potential dementia risk in their package inserts.

Conclusion

This study identified a list of medications associated with dementia risk, many of which lack dementia warnings on their labels. Increased monitoring is necessary for high-risk individuals, and further research is required to clarify these associations and improve patient safety.

Astrocytes phenomics as new druggable targets in healthy aging and Alzheimer's disease progression

For over a century after their discovery astrocytes were regarded merely as cells located among other brain cells to hold and give support to neurons. Astrocytes activation, "astrocytosis" or A1 functional state, was considered a detrimental mechanism against neuronal survival. Recently, the scientific view on astrocytes has changed. Accumulating evidence indicate that astrocytes are not homogeneous, but rather encompass heterogeneous subpopulations of cells that differ from each other in terms of transcriptomics, molecular signature, function and response in physiological and pathological conditions. In this review, we report and discuss the recent literature on the phenomic differences of astrocytes in health and their modifications in disease conditions, focusing mainly on the hippocampus, a region involved in learning and memory encoding, in the age-related memory impairments, and in Alzheimer's disease (AD) dementia. The morphological and functional heterogeneity of astrocytes in different brain regions may be related to their different housekeeping functions. Astrocytes that express diverse transcriptomics and phenomics are present in strictly correlated brain regions and they are likely responsible for interactions essential for the formation of the specialized neural circuits that drive complex behaviors. In the contiguous and interconnected hippocampal areas CA1 and CA3, astrocytes show different, finely regulated, and region-specific heterogeneity. Heterogeneous astrocytes have specific activities in the healthy brain, and respond differently to physiological or pathological stimuli, such as inflammaging present in normal brain aging or beta-amyloid-dependent neuroinflammation typical of AD. To become reactive, astrocytes undergo transcriptional, functional, and morphological changes that transform them into cells with different properties and functions. Alterations of astrocytes affect the neurovascular unit, the blood-brain barrier and reverberate to other brain cell populations, favoring or dysregulating their activities. It will be of great interest to understand whether the differential phenomics of astrocytes in health and disease can explain the diverse vulnerability of the hippocampal areas to aging or to different damaging insults, in order to find new astrocyte-targeted therapies that might prevent or treat neurodegenerative disorders.

Association between ankylosing spondylitis and neurodegenerative diseases: Systematic review and meta-analysis

BACKGROUND

Increasing evidence indicates the mechanism of overlapping immune dysfunction and inflammation disorder shared by ankylosing spondylitis (AS) and neurodegenerative diseases (NDs). However, the exact correlation between the two is still unclear. Different studies have reported inconsistent results about how AS and NDs are related.

OBJECTIVE

This study aimed to investigate the association between AS and risk of NDs.

METHODS

We searched electronic databases including PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials to identify studies reporting relationship between NDs risk and AS published before April 10th, 2024. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs) were estimated. All analyses were conducted using Stata V.12.0 software.

RESULTS

A total of 15 comparisons out of 10 studies involving 851,936 participants were included. The results showed that the risk of NDs was higher among AS patients than those who were not (OR: 1.36, 95% CI: 1.15-1.60, P<0.001). In addition, subgroup analysis showed that AS was associated with an increased risk of Parkinson's disease (PD) development (OR: 1.55, 95% CI: 1.31-1.83, P<0.001), whereas there is no observed association with Alzheimer's disease (AD) and dementia (OR: 1.22, 95% CI: 0.96-1.55, P=0.098; OR: 1.34, 95% CI: 0.96-1.87, P=0.089, respectively).

CONCLUSION

The current meta-analysis identified AS as a risk factor for the development of NDs. Clinicians should be aware of the potential association between these diseases. Further research is necessary to confirm the causal relationship and underlying mechanisms between AS and NDs.

Cognitive impairment in individuals with rheumatic diseases: the role of systemic inflammation, immunomodulatory medications, and comorbidities

Inflammation is an important risk factor, a potential therapeutic target for cognitive decline and dementia, and an inherent feature of autoimmune and immune-mediated rheumatic diseases. The risk of cognitive impairment and dementia is increased in individuals with immune-mediated rheumatic diseases, particularly in those with cardiovascular risk factors and cardiovascular disease. Immunomodulatory medications have been associated with a reduced risk of dementia, but whether this effect is mediated through their anti-inflammatory immunomodulating properties or other mechanisms, such as cardiovascular risk reduction, is unclear. A better understanding of the role of chronic inflammation as a modifiable risk factor for cognitive performance in rheumatic diseases will help inform opportunities for the management of cognitive impairment in people with rheumatic diseases and other chronic inflammatory diseases. In this Series paper, we discuss the epidemiology, risk factors, and current evidence on the role of immunomodulatory medications in cognitive impairment and dementia in people with rheumatic diseases.

Decoding paradoxical links of cytokine markers in cognition: Cross talk between physiology, inflammaging, and Alzheimer's disease- related cognitive decline

Recent research has revolutionized our understanding of memory consolidation by emphasizing the critical role of astrocytes, microglia, and immune cells in through cytokine signaling. Cytokines, compact proteins, play pivotal roles in neuronal development, synaptic transmission, and normal aging. This review explores the cellular mechanisms contributing to cognitive decline in inflammaging and Alzheimer's disease, highlighting the paradoxical effects of most studied cytokines (IL-1, IL-6, TNF-α) in brain function, which act as a double-edged sword in brain physiology, acting both as facilitators of healthy cognitive function and as a potential contributor to cognitive decline.

A comparative retrospective longitudinal study of arthritis risk and cognitive decline in older adults

Arthritis often results in unmet healthcare needs for older adults with cognitive decline, who may struggle to communicate pain or recall symptoms. However, the risk factors for arthritis in this group remain underexplored. We addressed this gap by identifying and comparing arthritis risk factors among older adults with varying cognitive statuses. Data from 334 participants with cognitive decline and 808 participants with normal cognition were analysed using the Korean Longitudinal Study of Aging, tracking arthritis diagnoses over 12 years with Kaplan-Meier curves and Cox proportional hazards regression. Results showed 47.6% of older adults with cognitive decline developed arthritis, compared with 30.1% with normal cognition. Key risk factors for the cognitive decline group included depressive symptoms (hazard ratio [HR]: 1.87), living alone (HR: 1.66), infrequent social interactions (HR: 1.42), and greater dependency in daily activities (HR: 1.41). In the normal cognition group, additional chronic illnesses (HR: 1.41) and higher body mass index (HR: 1.09) were significant risk factors. Understanding these distinct risk factors is crucial for preventing and managing arthritis among at risk groups. Moreover, these findings can assist in developing comprehensive public health strategies integrating mental health and social support to improve health outcomes for older adults with cognitive decline.

Metabolic and Immune System Dysregulation: Unraveling the Connections between Alzheimer's Disease, Diabetes, Inflammatory Bowel Diseases, and Rheumatoid Arthritis

Alzheimer's disease (AD), diabetes mellitus (DM), inflammatory bowel diseases (IBD), and rheumatoid arthritis (RA) are chronic conditions affecting millions globally. Despite differing clinical symptoms, these diseases share pathophysiological mechanisms involving metabolic and immune system dysregulation. This paper examines the intricate connections between these disorders, focusing on shared pathways such as insulin resistance, lipid metabolism dysregulation, oxidative stress, and chronic inflammation. An important aspect is the role of amyloid-beta plaques and tau protein tangles, which are hallmark features of AD. These protein aggregates are influenced by metabolic dysfunction and inflammatory processes similar to those seen in DM, RA, and IBD. This manuscript explores how amyloid and tau pathologies may be exacerbated by shared metabolic and immune dysfunction. Additionally, this work discusses the gut-brain axis and the influence of gut microbiota in mediating disease interactions. Understanding these commonalities opens new avenues for multi-targeted therapeutic approaches that address the root causes rather than merely the symptoms of these conditions. This integrative perspective could lead to more effective interventions and improved patient outcomes, emphasizing the importance of a unified approach in managing these interconnected diseases.

Causal relationships between rheumatoid arthritis and neurodegenerative diseases: a two-sample univariable and multivariable Mendelian randomization study

Background

Observational research has highlighted a potential relationship between rheumatoid arthritis (RA) and neurodegenerative diseases (NDs). However, the confirmation of a causal connection is impeded by the inherent limitations of such studies, including vulnerability to confounding factors and the possibility of reverse causality. This study employs a two-sample Mendelian randomization (MR) approach to assess the causal impact of RA on three NDs, including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS).

Methods

We aggregated data from genome-wide association studies (GWASs) targeting RA or NDs within populations of European descent. Single nucleotide polymorphisms (SNPs) with robust associations to RA were identified as instrumental variables (IVs). To estimate the association between RA and AD, PD, and ALS, we utilized the inverse variance weighted (IVW) method in our univariable MR (UVMR) analysis. Validation of the IVW results ensued through supplementary analyses using MR-Egger and weighted median methods. The multivariable MR (MVMR) analysis was conducted, adjusting for body mass index (BMI), alcohol drinking, and type 2 diabetes mellitus (T2DM).

Results

The UVMR analysis, based on the IVW method, revealed a significantly positive causal association between RA and late-onset (LO) AD (OR [95% CI] = 1.084 [1.020-1.153]; p = 9.980 × 10-3), while suggesting a possible inverse relationship with PD (OR [95% CI] = 0.727 [0.563-0.938]; p = 0.014). Our study did not detect any causal connections between RA and early-onset (EO) AD, atypical or mixed (AM) AD, and ALS (all p > 0.05). The MVMR analysis results indicated that after adjusting for alcohol drinking, RA remains a risk factor for LOAD (OR [95% CI] = 1.094 [1.024-1.169]; p = 0.008). However, MVMR analysis revealed no causal connections between RA and PD after adjustments for BMI, alcohol drinking, or T2DM (all p > 0.05). Sensitivity analyses showed no evidence of heterogeneity and horizontal pleiotropy.

Conclusions

This research provides genetic evidence indicating that RA potentially causes an increased risk of developing LOAD and PD. Such a revelation underscores the importance for individuals suffering from RA to be vigilant about the potential emergence of LOAD and PD. Ongoing monitoring and prompt detection are essential for successfully managing and intervening in this possible risk.

Alzheimer incidence and prevalence with and without asthma: A Medicare cohort study

BACKGROUND

International data suggest that asthma, like other inflammatory diseases, might increase Alzheimer disease (AD) risk.

OBJECTIVE

We sought to explore risk pathways and future mitigation strategies by comparing diagnostic claims-based AD incidence and prevalence among US patients with asthma with those without asthma.

METHODS

This cohort study included a national Medicare 20% random sample (2013-2015). Adult patients with asthma with more than 12 months continuous Medicare were compared with subjects without asthma overall and as matched. Asthma was defined by 1 inpatient or 2 outpatient codes for asthma. The main outcomes were 2-year incident or prevalent AD defined by International Classification of Diseases, Ninth Revision code 331.0 or Tenth Revision code G30.0, G30.1, G30.8, or G30.9.

RESULTS

Among 5,460,732 total beneficiaries, 678,730 patients were identified with baseline asthma and more often identified as Black or Hispanic, were Medicaid eligible, or resided in a highly disadvantaged neighborhood than those without asthma. Two-year incidence of AD was 1.4% with asthma versus 1.1% without asthma; prevalence was 7.8% versus 5.4% (both P ≤ .001). Per 100,000 patients over 2 years, 303 more incident AD diagnoses occurred in those with asthma, with 2,425 more prevalent cases (P < .001). Multivariable models showed that asthma had greater odds of 2-year AD incidence (adjusted odds ratio, 1.33 [95% CI, 1.29-1.36]; matched 1.2 [95% CI, 1.17-1.24]) and prevalence (adjusted odds ratio, 1.48 [95% CI, 1.47-1.50]; matched 1.25 [95% CI, 1.22-1.27]).

CONCLUSIONS

Asthma was associated with 20% to 33% increased 2-year incidence and 25% to 48% increased prevalence of claims-based AD in this nationally representative US sample. Future research should investigate risk pathways of underlying comorbidities and social determinants as well as whether there are potential asthma treatments that may preserve brain health.

Endothelial dysfunction in neurodegenerative disease: Is endothelial inflammation an overlooked druggable target?

Neurological diseases with a neurodegenerative component have been associated with alterations in the cerebrovasculature. At the anatomical level, these are centred around changes in cerebral blood flow and vessel organisation. At the molecular level, there is extensive expression of cellular adhesion molecules and increased release of pro-inflammatory mediators. Together, these has been found to negatively impact blood-brain barrier integrity. Systemic inflammation has been found to accelerate and exacerbate endothelial dysfunction, neuroinflammation and degeneration. Here, we review the role of cerebrovasculature dysfunction in neurodegenerative disease and discuss the potential contribution of intermittent pro-inflammatory systemic disease in causing endothelial pathology, highlighting a possible mechanism that may allow broad-spectrum therapeutic targeting in the future.

Cross-phenotype associations between Alzheimer's Disease and its comorbidities may provide clues to progression

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease worldwide, with one in nine people over the age of 65 living with the disease in 2023. In this study, we used a phenome wide association study (PheWAS) approach to identify cross-phenotype between previously identified genetic associations for AD and electronic health record (EHR) diagnoses from the UK Biobank (UKBB) (n=361,194 of European ancestry) and the eMERGE Network (n=105,108 of diverse ancestry). Based on 497 previously identified AD-associated variants from the Alzheimer's Disease Variant Portal (ADVP), we found significant associations primarily in immune and cardiac related diseases in our PheWAS. Replicating variants have widespread impacts on immune genes in diverse tissue types. This study demonstrates the potential of using the PheWAS strategy to improve our understanding of AD progression as well as identify potential drug repurposing opportunities for new treatment and disease prevention strategies.

Association of Tumor Necrosis Factor-α Inhibitors with Incident Dementia: Analysis Based on Population-Based Cohort Studies

BACKGROUND AND OBJECTIVE

Preliminary evidence suggests a possible preventive effect of tumor necrosis factor-α inhibitors (TNFi) on incident dementia. The objective of the analysis was to investigate the association between TNFi and the risk of incident dementia in a population undergoing treatment for rheumatological disorders.

METHODS

We followed patients aged ≥ 65 years with dementia and rheumatological conditions in two cohort studies, DANBIO (N = 21,538), a Danish clinical database, and AOK PLUS (N = 7112), a German health insurance database. We defined incident dementia using diagnostic codes and/or medication use and used Cox regression to compare the associations of TNFi with other rheumatological therapies on the risk of dementia. To ensure that the patients were receiving long-term medication, we included patients with rheumatic diseases and systemic therapies.

RESULTS

We observed similar trends towards a lower risk of dementia associated with TNFi versus other anti-inflammatory agents in both cohorts (hazard ratios were 0.92 [95% confidence interval 0.76, 1.10] in DANBIO and 0.89 [95% confidence interval 0.63, 1.24] in AOK PLUS, respectively).

CONCLUSIONS

Tumor necrosis factor-α inhibitors may decrease the risk of incident dementia although the association did not reach statistical significance in this analysis. Further research, ideally with randomization, is needed to gauge the potential of repurposing TNFi for dementia prevention and/or treatment.

The association between circulating CD34+CD133+ endothelial progenitor cells and reduced risk of Alzheimer's disease in the Framingham Heart Study

Aim

Endothelial dysfunction has been associated with both cerebrovascular pathology and Alzheimer's disease (AD). However, the connection between circulating endothelial cells and the risk of AD remains uncertain. The objective was to leverage data from the Framingham Heart Study to investigate various circulating endothelial subtypes and their potential correlations with the risk of AD.

Methods

The study conducted data analyses using Cox proportional hazard regression and linear regression methods. Additionally, genome-wide association study (GWAS) was carried out to further explore the data.

Results

Among the eleven distinct circulating endothelial subtypes, only circulating endothelial progenitor cells (EPCs) expressing CD34+CD133+ were found to be negatively and dose-dependently associated with reduced AD risk. This association persisted even after adjusting for age, sex, years of education, apolipoprotein E (APOE) ε4 status, and various vascular diseases. Particularly noteworthy was the significant association observed in individuals with hypertension and cerebral microbleeds. Consistently, positive associations were identified between CD34+CD133+ EPCs and specific brain regions, such as higher proportions of circulating CD34+CD133+ cells correlating with increased volumes of white matter and the hippocampus. Additionally, a GWAS study unveiled that CD34+CD133+ cells influenced AD risk specifically in individuals with homozygous genotypes for variants in two stem cell-related genes: kirre like nephrin family adhesion molecule 3 (KIRREL3, rs580382 CC and rs4144611 TT) and exocyst complex component 6B (EXOC6B, rs61619102 CC).

Conclusions

The findings suggest that circulating CD34+CD133+ EPCs possess a protective effect and may offer a new therapeutic avenue for AD, especially in individuals with vascular pathology and those carrying specific genotypes of KIRREL3 and EXOC6B genes.

Association between disease-modifying antirheumatic drugs for rheumatoid arthritis and risk of incident dementia: a systematic review with meta-analysis

BACKGROUND

Dysregulation of several inflammatory cytokines including tumour necrosis factor (TNF) in dementia patients has also been identified as a key factor in the pathogenesis of rheumatoid arthritis (RA). We aimed to investigate the association of disease-modifying antirheumatic drugs (DMARDs) therapy for RA with risk of incident dementia.

METHODS

Electronic database searches of PubMed, EMBASE and Cochrane Library were performed. Observational studies that assessed the association of dementia with DMARDs in RA were included. Pooled risk ratios (RRs) with 95% CIs were used as summary statistic. The certainty of evidence was judged by using the Grading of Recommendations Assessment, Development and Evaluation system.

RESULTS

Overall, 14 studies involving 940 442 patients with RA were included. Pooled RR for developing dementia was 0.76 (95% CI 0.72 to 0.80) in patients taking biological DMARDs overall versus those taking conventional synthetic DMARDs, with 24% for TNF inhibitors (RR 0.76, 95% CI 0.71 to 0.82), 24% for non-TNF biologics (RR 0.76, 95% CI 0.70 to 0.83), separately. There was a significant subgroup effect among different types of TNF inhibitors (RR 0.58 [95%CI 0.53 to 0.65], 0.65 [95% CI 0.59 to 0.72], 0.80 [95% CI 0.72 to 0.88] for etanercept, adalimumab, infliximab, respectively; p value between groups=0.002). However, compared with non-users of DMARDs or investigative treatment, no significant effect on dementia incidence was observed in those receiving conventional synthetic DMARDs overall (RR 0.84, 95% CI 0.59 to 1.20), methotrexate (RR 0.78, 95% CI 0.54 to 1.12), hydroxychloroquine (RR 0.95, 95% CI 0.63 to 1.44), except for sulfasalazine (RR 1.27, 95% CI 1.06 to 1.50).

CONCLUSIONS

Biological DMARDs for RA are associated with decreased dementia risk, while protective effect is not observed in conventional synthetic DMARDs. Controlled clinical trials on TNF inhibitors are necessary to test their neuroprotective potentials.

The oral-brain axis: can periodontal pathogens trigger the onset and progression of Alzheimer's disease?

Alzheimer's disease (AD) is the most prevalent form of dementia, characterized by a progressive cognitive decline. Sporadic AD, accounting for more than 95% of cases, may arise due to the influence of environmental factors. It was reported that periodontitis, a common oral ailment, shares several risk factors with AD, including advanced age, smoking, diabetes, and hypertension, among others. Periodontitis is an inflammatory disease triggered by dysbiosis of oral microorganisms, whereas Alzheimer's disease is characterized by neuroinflammation. Many studies have indicated that chronic inflammation can instigate brain AD-related pathologies, including amyloid-β plaques, Tau protein hyperphosphorylation, neuroinflammation, and neurodegeneration. The potential involvement of periodontal pathogens and/or their virulence factors in the onset and progression of AD by the oral-brain axis has garnered significant attention among researchers with ongoing investigations. This review has updated the periodontal pathogens potentially associated with AD, elucidating their impact on the central nervous system, immune response, and related pathological processes in the brain to provide valuable insights for future research on the oral-brain axis.

Rheumatoid arthritis is a protective factor against Alzheimer's disease: a bidirectional two-sample Mendelian randomization study

BACKGROUND

Epidemiological evidence suggests that there is an association between rheumatoid arthritis (RA) and Alzheimer's disease (AD). However, the causal relationship between RA and AD remains unclear. Therefore, this study aimed to investigate the causal relationship between RA and AD.

METHODS

Using publicly available genome-wide association study datasets, bidirectional two-sample Mendelian randomization (TSMR) was performed using the inverse-variance weighted (IVW), weighted median, MR‒Egger regression, simple mode, and weighted mode methods.

RESULTS

The results of MR for the causal effect of RA on AD (IVW, odds ratio [OR] = 0.959, 95% confidence interval [CI]: 0.941-0.978, P = 2.752E-05; weighted median, OR = 0.960, 95% CI: 0.937-0.984, P = 0.001) revealed a causal association between genetic susceptibility to RA and an increased risk of AD. The results of MR for the causal effect of AD on RA (IVW, OR = 0.978, 95% CI: 0.906-1.056, P = 0.576; weighted median, OR = 0.966, 95% CI: 0.894-1.043, P = 0.382) indicated that there was no causal association between genetic susceptibility to AD and an increased risk of RA.

CONCLUSIONS

The results of this two-way two-sample Mendelian randomization analysis revealed a causal association between genetic susceptibility to RA and a reduced risk of AD but did not reveal a causal association between genetic susceptibility to AD and an increased or reduced risk of RA.

Peripheral inflammation is a potential etiological factor in Alzheimer's disease

Peripheral inflammation could constitute a risk factor for AD. This review summarizes the research related to peripheral inflammation that appears to have a relationship with Alzheimer's disease. We find there are significant associations between AD and peripheral infection induced by various pathogens, including herpes simplex virus type 1, cytomegalovirus, Epstein-Barr virus, human immunodeficiency virus, severe acute respiratory syndrome coronavirus 2, Porphyromonas gingivalis, Helicobacter pylori, and Toxoplasma gondii. Chronic inflammatory diseases are also reported to contribute to the pathophysiology of AD. The mechanisms by which peripheral inflammation affects the pathophysiology of AD are complex. Pathogen-derived neurotoxic molecule composition, disrupted BBB, and dysfunctional neurogenesis may all play a role in peripheral inflammation, promoting the development of AD. Anti-pathogenic medications and anti-inflammatory treatments are reported to decrease the risk of AD. Studies that could improve understanding the associations between AD and peripheral inflammation are needed. If our assumption is correct, early intervention against inflammation may be a potential method of preventing and treating AD.

The RESIST Study: Examining Cognitive Change in Rheumatoid Arthritis Patients with Mild Cognitive Impairment Being Treated with a TNF-Inhibitor Compared to a Conventional Synthetic Disease-Modifying Anti-Rheumatic Drug

Background

Evidence suggests that TNF inhibitors (TNFi) used to treat rheumatoid arthritis (RA) may protect against Alzheimer's disease progression by reducing inflammation.

Objective

To investigate whether RA patients with mild cognitive impairment (MCI) being treated with a TNFi show slower cognitive decline than those being treated with a conventional synthetic disease-modifying anti-rheumatic drug (csDMARD).

Methods

251 participants with RA and MCI taking either a csDMARD (N = 157) or a TNFi (N = 94) completed cognitive assessments at baseline and 6-month intervals for 18 months. It was hypothesized that those taking TNFis would show less decline on the primary outcome of Free and Cued Selective Reminding Test with Immediate Recall (FCSRT-IR) and the secondary outcome of Montreal Cognitive Assessment (MoCA).

Results

No significant changes in FCSRT-IR scores were observed in either treatment group. There was no significant difference in FCSRT-IR between treatment groups at 18 months after adjusting for baseline (mean difference = 0.5, 95% CI = -1.3, 2.3). There was also no difference in MoCA score (mean difference = 0.4, 95% CI = -0.4, 1.3).

Conclusions

There was no cognitive decline in participants with MCI being treated with TNFis and csDMARDs, raising the possibility both classes of drug may be protective. Future studies should consider whether controlling inflammatory diseases using any approach is more important than a specific therapeutic intervention.

Risk of dementia among older patients with lymphoma: A Danish nationwide matched cohort study

INTRODUCTION

Treatment of lymphoma can be associated with cognitive challenges, and some patients may fear development of dementia as long-term complication. Studies report a lower risk of dementia after cancer. Some believe this difference to be a protective mechanism of cancer, others believe it to be driven by bias. The risk of developing dementia after lymphoma has not been investigated in a population-based setting. The aim of this study was to identify the risk of being diagnosed with dementia after lymphoma treatment.

MATERIALS AND METHODS

This Danish nationwide matched cohort study included patients aged ≥65 years with a first-time diagnosis of a non-central nervous system lymphoma between 2005 and 2018 in complete remission after treatment with chemotherapy. Patients diagnosed with dementia or treated with dementia medication before lymphoma diagnosis were excluded. Each patient was matched 1:5 on sex, year of birth, and a modified Charlson comorbidity index. Patients and matched comparators were followed from the corresponding patient's date of complete remission. The risk of developing dementia was calculated using cause-specific hazard ratios (HR), and the cumulative risk was estimated by Aalen-Johansen with death as the competing risk.

RESULTS

A total of 3,244 patients and 16,220 matched comparators were included in the study. There was no difference in risk of all-cause dementia among patients with lymphoma compared to matched comparators with cause-specific HR of 0.85 (95% confidence interval [CI]: 0.70;1.04). The risk of both Alzheimer's disease and non-Alzheimer's dementia was equal among patients and comparators: HR 0.89 (95% CI: 0.66;1.21) and 0.82 (95% CI: 0.63;1.07), respectively. Stratified by lymphoma subtype, age, or year of diagnosis, the risk of all-cause dementia remained equal among patients and matched comparators. The cumulative risk of all-cause dementia was significantly lower among patients with lymphoma compared to matched comparators (Gray's test p < 0.001), probably reflecting higher mortality in patients with lymphoma.

DISCUSSION

The risk of all-cause dementia, Alzheimer's disease, and non-Alzheimer's dementia was equal among older patients with lymphoma compared to matched comparators. Our data suggests that risk of developing dementia is not changed after lymphoma treatment.

Polyamine Dysregulation and Nucleolar Disruption in Alzheimer's Disease

A hypothesis of Alzheimer's disease etiology is proposed describing how cellular stress induces excessive polyamine synthesis and recycling which can disrupt nucleoli. Polyamines are essential in nucleolar functions, such as RNA folding and ribonucleoprotein assembly. Changes in the nucleolar pool of anionic RNA and cationic polyamines acting as counterions can cause significant nucleolar dynamics. Polyamine synthesis reduces S-adenosylmethionine which, at low levels, triggers tau phosphorylation. Also, polyamine recycling reduces acetyl-CoA needed for acetylcholine, which is low in Alzheimer's disease. Extraordinary nucleolar expansion and/or contraction can disrupt epigenetic control in peri-nucleolar chromatin, such as chromosome 14 with the presenilin-1 gene; chromosome 21 with the amyloid precursor protein gene; chromosome 17 with the tau gene; chromosome 19 with the APOE4 gene; and the inactive X chromosome (Xi; aka "nucleolar satellite") with normally silent spermine synthase (polyamine synthesis) and spermidine/spermine-N1-acetyltransferase (polyamine recycling) alleles. Chromosomes 17, 19 and the Xi have high concentrations of Alu elements which can be transcribed by RNA polymerase III if positioned nucleosomes are displaced from the Alu elements. A sudden flood of Alu RNA transcripts can competitively bind nucleolin which is usually bound to Alu sequences in structural RNAs that stabilize the nucleolar heterochromatic shell. This Alu competition leads to loss of nucleolar integrity with leaking of nucleolar polyamines that cause aggregation of phosphorylated tau. The hypothesis was developed with key word searches (e.g., PubMed) using relevant terms (e.g., Alzheimer's, lupus, nucleolin) based on a systems biology approach and exploring autoimmune disease tautology, gaining synergistic insights from other diseases.

Inflammation, Autoimmunity and Neurodegenerative Diseases, Therapeutics and Beyond

Neurodegenerative disease (ND) incidence has recently increased due to improved life expectancy. Alzheimer's (AD) or Parkinson's disease (PD) are the most prevalent NDs. Both diseases are poly genetic, multifactorial and heterogenous. Preventive medicine, a healthy diet, exercise, and controlling comorbidities may delay the onset. After the diseases are diagnosed, therapy is needed to slow progression. Recent studies show that local, peripheral and age-related inflammation accelerates NDs' onset and progression. Patients with autoimmune disorders like inflammatory bowel disease (IBD) could be at higher risk of developing AD or PD. However, no increase in ND incidence has been reported if the patients are adequately diagnosed and treated. Autoantibodies against abnormal tau, β amyloid and α- synuclein have been encountered in AD and PD and may be protective. This discovery led to the proposal of immune-based therapies for AD and PD involving monoclonal antibodies, immunization/ vaccines, pro-inflammatory cytokine inhibition and anti-inflammatory cytokine addition. All the different approaches have been analysed here. Future perspectives on new therapeutic strategies for both disorders are concisely examined.

The Role of TNF-α in Alzheimer's Disease: A Narrative Review

This review analyzes the role of TNF-α and its increase in biological fluids in mild cognitive impairment, and Alzheimer's disease (AD). The potential inhibition of TNF-α with pharmacological strategies paves the way for preventing AD and improving cognitive function in people at risk for dementia. We conducted a narrative review to characterize the evidence in relation to the involvement of TNF-α in AD and its possible therapeutic inhibition. Several studies report that patients with RA and systemic inflammatory diseases treated with TNF-α blocking agents reduce the probability of emerging dementia compared with the general population. Animal model studies also showed interesting results and are discussed. An increasing amount of basic scientific data and clinical studies underscore the importance of inflammatory processes and subsequent glial activation in the pathogenesis of AD. TNF-α targeted therapy is a biologically plausible approach for cognition preservation and further trials are necessary to investigate the potential benefits of therapy in populations at risk of developing AD.

Adverse cognitive effects of glucocorticoids: A systematic review of the literature

OBJECTIVES

Glucocorticoids as a drug class are widely used in the treatment of many conditions including more recently as one of the mainstay treatments for the SARS-CoV-2 infection. The physiological adverse effects are well described. However, less is known and understood about the potentially deleterious neuro-cognitive effects of this class of medication.

METHODS

We carried out a systematic review of the literature using two separate search strategies. The first focussed on the rates of reporting of adverse cognitive effects of glucocorticoid use in randomised controlled trials. The second looked at those studies focussing directly on adverse cognitive effects associated with the use of glucocorticoids. MEDLINE, Embase and Cochrane Library was searched for randomised controlled trials utilising glucocorticoids as a part of a treatment regimen. Additionally, these databases were also used to search for articles looking directly at the adverse cognitive effects of glucocorticoids.

RESULTS

Of the forty-three RCTs included as a part of the first search strategy, only one (2.3%) included specific documentation pertaining to cognitive side effects. As a part of the twenty studies included in the second search strategy, eleven of the included studies (55%) were able to demonstrate a correlation between glucocorticoid use and decreased cognition. Most studies within this strategy showed that GCs predominately affected hippocampus-dependent functions such as memory, while sparing executive function and attention.

CONCLUSIONS

Overall, the data reporting of adverse clinical effects of glucocorticoid use is poor in recent RCTs. Given the demonstrable effect on predominately hippocampal-dependent cognitive functions evident within the literature, more thorough documentation is needed within clinical research to fully appreciate the potentially widespread nature of these effects.

Cross-phenotype associations between Alzheimer's Disease and its comorbidities may provide clues to progression

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease worldwide, with one in nine people over the age of 65 living with the disease in 2023. In this study, we used a phenome wide association study (PheWAS) approach to identify cross-phenotype associations between previously identified genetic AD and for electronic health record (EHR) diagnoses from the UK Biobank (UKBB) (n=361,194 of European ancestry) and the eMERGE Network (n=105,108 of diverse ancestry). Based on 497 previously identified AD-associated variants from the Alzheimer's Disease Variant Portal (ADVP), we found significant associations primarily in immune and cardiac related diseases in our PheWAS. Replicating variants have widespread impacts on immune genes in diverse tissue types. This study demonstrates the potential of using the PheWAS strategy to improve our understanding of AD progression as well as identify potential drug repurposing opportunities for new treatment and disease prevention strategies.

The influence of physiological and pathological perturbations on blood-brain barrier function

The blood-brain barrier (BBB) is located at the interface between the vascular system and the brain parenchyma, and is responsible for communication with systemic circulation and peripheral tissues. During life, the BBB can be subjected to a wide range of perturbations or stresses that may be endogenous or exogenous, pathological or therapeutic, or intended or unintended. The risk factors for many diseases of the brain are multifactorial and involve perturbations that may occur simultaneously (e.g., two-hit model for Alzheimer's disease) and result in different outcomes. Therefore, it is important to understand the influence of individual perturbations on BBB function in isolation. Here we review the effects of eight perturbations: mechanical forces, temperature, electromagnetic radiation, hypoxia, endogenous factors, exogenous factors, chemical factors, and pathogens. While some perturbations may result in acute or chronic BBB disruption, many are also exploited for diagnostic or therapeutic purposes. The resultant outcome on BBB function depends on the dose (or magnitude) and duration of the perturbation. Homeostasis may be restored by self-repair, for example, via processes such as proliferation of affected cells or angiogenesis to create new vasculature. Transient or sustained BBB dysfunction may result in acute or pathological symptoms, for example, microhemorrhages or hypoperfusion. In more extreme cases, perturbations may lead to cytotoxicity and cell death, for example, through exposure to cytotoxic plaques.

Neuropathologic evaluation of cerebrovascular disease in patients with rheumatoid arthritis

OBJECTIVES

Active RA has been associated with an increased risk of both cardiovascular and peripheral vascular disease. We aimed to compare cerebrovascular changes in patients with and without RA, both with and without a neuropathologic diagnosis of neurodegenerative disease.

METHODS

Patients with RA (n = 32) who died and underwent autopsy between 1994 and 2021 were matched to non-RA controls (n = 32) on age, sex and level of neurodegenerative proteinopathy. Routine neuropathologic examination was performed at the time of autopsy. Cerebrovascular disease severity was evaluated using modified Kalaria and Strozyk scales. Clinical dementia diagnoses were manually collected from patients' medical records.

RESULTS

Prior to death, 15 (47%) RA patients and 14 (44%) controls were diagnosed with dementia; 9 patients in each group (60% and 64%, respectively) had Alzheimer's disease. The prevalence of cerebral amyloid angiopathy, microinfarcts, infarcts or strokes was found to be similar between groups. Patients with RA were more likely to have more severe vascular changes in the basal ganglia by Kalaria scale (P = 0.04), but not in other brain areas. There were no significant differences in the presence of large infarcts, lacunar infarcts or leukoencephalopathy by Strozyk scale. Among patients with RA and no clinical diagnosis of dementia, the majority had mild-moderate cerebrovascular abnormalities, and a subset of patients had Alzheimer's disease neuropathologic changes.

CONCLUSION

In this small series of autopsies, patients with and without RA had largely similar cerebrovascular pathology when controlling for neurodegenerative proteinopathies, although patients with RA exhibited more pronounced cerebrovascular disease in the basal ganglia.

Peripheral Low Level Chronic LPS Injection as a Model of Neutrophil Activation in the Periphery and Brain in Mice

Lipopolysaccharide-induced (LPS) inflammation is used as model to understand the role of inflammation in brain diseases. However, no studies have assessed the ability of peripheral low-level chronic LPS to induce neutrophil activation in the brain. Subclinical levels of LPS were injected intraperitoneally into mice to investigate impacts on neutrophil frequency and activation. Neutrophil activation, as measured by CD11b expression, peaked in the periphery after 4 weeks of weekly injections. Neutrophil frequency and activation increased in the periphery 4-12 hours and 4-8 hours after the fourth and final injection, respectively. Increased levels of G-CSF, TNFa, IL-6, and CXCL2 were observed in the plasma along with increased neutrophil elastase, a marker of neutrophil extracellular traps, peaking 4 hours following the final injection. Neutrophils and neutrophil activation were increased in the brain of LPS injected mice when compared to saline-injected mice 4 hours and 4-8 hours after the final injection, respectively. These results indicate that subclinical levels of peripheral LPS induces neutrophil activation in the periphery and brain. This model of chronic low-level systemic inflammation could be used to understand how neutrophils may act as mediators of the periphery-brain axis of inflammation with age and/or in mouse models of neurodegenerative or neuroinflammatory disease.

Novel small molecules inhibit proteotoxicity and inflammation: Mechanistic and therapeutic implications for Alzheimer's Disease, healthspan and lifespan- Aging as a consequence of glycolysis

Inflammation drives many age-related, especially neurological, diseases, and likely mediates age-related proteotoxicity. For example, dementia due to Alzheimer's Disease (AD), cerebral vascular disease, many other neurodegenerative conditions is increasingly among the most devastating burdens on the American (and world) health system and threatens to bankrupt the American health system as the population ages unless effective treatments are developed. Dementia due to either AD or cerebral vascular disease, and plausibly many other neurodegenerative and even psychiatric conditions, is driven by increased age-related inflammation, which in turn appears to mediate Abeta and related proteotoxic processes. The functional significance of inflammation during aging is also supported by the fact that Humira, which is simply an antibody to the pro-inflammatory cytokine TNF-a, is the best-selling drug in the world by revenue. These observations led us to develop parallel high-throughput screens to discover small molecules which inhibit age-related Abeta proteotoxicity in a C. elegans model of AD AND LPS-induced microglial TNF-a. In the initial screen of 2560 compounds (Microsource Spectrum library) to delay Abeta proteotoxicity, the most protective compounds were, in order, phenylbutyrate, methicillin, and quetiapine, which belong to drug classes (HDAC inhibitors, beta lactam antibiotics, and tricyclic antipsychotics, respectably) already robustly implicated as promising to protect in neurodegenerative diseases, especially AD. RNAi and chemical screens indicated that the protective effects of HDAC inhibitors to reduce Abeta proteotoxicity are mediated by inhibition of HDAC2, also implicated in human AD, dependent on the HAT Creb binding protein (Cbp), which is also required for the protective effects of both dietary restriction and the daf-2 mutation (inactivation of IGF-1 signaling) during aging. In addition to methicillin, several other beta lactam antibiotics also delayed Abeta proteotoxicity and reduced microglial TNF-a. In addition to quetiapine, several other tricyclic antipsychotic drugs also delayed age-related Abeta proteotoxicity and increased microglial TNF-a, leading to the synthesis of a novel congener, GM310, which delays Abeta as well as Huntingtin proteotoxicity, inhibits LPS-induced mouse and human microglial and monocyte TNF-a, is highly concentrated in brain after oral delivery with no apparent toxicity, increases lifespan, and produces molecular responses highly similar to those produced by dietary restriction, including induction of Cbp inhibition of inhibitors of Cbp, and genes promoting a shift away from glycolysis and toward metabolism of alternate (e.g., lipid) substrates. GM310, as well as FDA-approved tricyclic congeners, prevented functional impairments and associated increase in TNF-a in a mouse model of stroke. Robust reduction of glycolysis by GM310 was functionally corroborated by flux analysis, and the glycolytic inhibitor 2-DG inhibited microglial TNF-a and other markers of inflammation, delayed Abeta proteotoxicity, and increased lifespan. These results support the value of phenotypic screens to discover drugs to treat age-related, especially neurological and even psychiatric diseases, including AD and stroke, and to clarify novel mechanisms driving neurodegeneration (e.g., increased microglial glycolysis drives neuroinflammation and subsequent neurotoxicity) suggesting novel treatments (selective inhibitors of microglial glycolysis).

TNF and TNF receptors as therapeutic targets for rheumatic diseases and beyond

The cytokine TNF signals via two distinct receptors, TNF receptor 1 (TNFR1) and TNFR2, and is a central mediator of various immune-mediated diseases. Indeed, TNF-neutralizing biologic drugs have been in clinical use for the treatment of many inflammatory pathological conditions, including various rheumatic diseases, for decades. TNF has pleiotropic effects and can both promote and inhibit pro-inflammatory processes. The integrated net effect of TNF in vivo is a result of cytotoxic TNFR1 signalling and the stimulation of pro-inflammatory processes mediated by TNFR1 and TNFR2 and also TNFR2-mediated anti-inflammatory and tissue-protective activities. Inhibition of the beneficial activities of TNFR2 might explain why TNF-neutralizing drugs, although highly effective in some diseases, have limited benefit in the treatment of other TNF-associated pathological conditions (such as graft-versus-host disease) or even worsen the pathological condition (such as multiple sclerosis). Receptor-specific biologic drugs have the potential to tip the balance from TNFR1-mediated activities to TNFR2-mediated activities and enable the treatment of diseases that do not respond to current TNF inhibitors. Accordingly, a variety of reagents have been developed that either selectively inhibit TNFR1 or selectively activate TNFR2. Several of these reagents have shown promise in preclinical studies and are now in, or approaching, clinical trials.

Research on the anti-ageing mechanism of Prunella vulgaris L

Prunella vulgaris L. (P. vulgaris) has long been considered to have antipyretic, analgesic and anti-inflammatory effects, lowering blood lipids and pressure. Many studies show that in addition to the traditional telomere attrition, DNA damage and epigenetic changes, immunosenescence is also a new possibility to explore the mechanism of ageing. Therefore, this herb may have potential anti-ageing effects. Typically, there are a series of markers that identify senescent cells, such as superoxide dismutase (SOD)2, an inhibitor of CDK4 (p16^INK4A), tumor necrosis factor (TNF)-α, immune cells number, proliferation, and nuclear abnormalities. These changes rarely present in young tissues, while greatly increasing in response to ageing. Firstly, the ageing model of the Institute of Cancer Research (ICR) mouse was established by D-galactose subcutaneous injection. Then, SOD2, p16^INK4A and TNF-α were detected by quantitative Real-time PCR (qPCR), Western Blot (WB) and Enzyme-Linked Immunosorbent Assay (ELISA). Simultaneously, senescent cells in livers were stained by hematoxylin and eosin (HE). The viability of splenocytes was detected by Cell Counting Kit-8(CCK-8). The difference in specific immune cells (NK cells, B lymphocytes and T lymphocytes) was detected by flow cytometry. Both low (100 mg/kg) and high (300 mg/kg) concentrations of P. vulgaris treated ageing ICR mice show anti-ageing alterations, such as p16^INK4A decreased approximately 1/2 and SOD2 tripled in livers, TNF-α decreased from 1 to 0.6 in plasma, and T cells increased from 0.09 to 0.19%. Compared with the ageing group, the spleen cells in the Prunella-treated group had stronger proliferation ability. Thus, P. vulgaris could have an anti-ageing effect. This is the first study to demonstrate the anti-ageing effect of P. vulgaris. It may also be capable of preventing a variety of age-related diseases.

The role of peripheral inflammatory insults in Alzheimer's disease: a review and research roadmap

Peripheral inflammation, defined as inflammation that occurs outside the central nervous system, is an age-related phenomenon that has been identified as a risk factor for Alzheimer's disease. While the role of chronic peripheral inflammation has been well characterized in the context of dementia and other age-related conditions, less is known about the neurologic contribution of acute inflammatory insults that take place outside the central nervous system. Herein, we define acute inflammatory insults as an immune challenge in the form of pathogen exposure (e.g., viral infection) or tissue damage (e.g., surgery) that causes a large, yet time-limited, inflammatory response. We provide an overview of the clinical and translational research that has examined the connection between acute inflammatory insults and Alzheimer's disease, focusing on three categories of peripheral inflammatory insults that have received considerable attention in recent years: acute infection, critical illness, and surgery. Additionally, we review immune and neurobiological mechanisms which facilitate the neural response to acute inflammation and discuss the potential role of the blood-brain barrier and other components of the neuro-immune axis in Alzheimer's disease. After highlighting the knowledge gaps in this area of research, we propose a roadmap to address methodological challenges, suboptimal study design, and paucity of transdisciplinary research efforts that have thus far limited our understanding of how pathogen- and damage-mediated inflammatory insults may contribute to Alzheimer's disease. Finally, we discuss how therapeutic approaches designed to promote the resolution of inflammation may be used following acute inflammatory insults to preserve brain health and limit progression of neurodegenerative pathology.

MLKL deficiency protects against low-grade, sterile inflammation in aged mice

MLKL and RIPK3 are the core signaling proteins of the inflammatory cell death pathway, necroptosis, which is a known mediator and modifier of human disease. Necroptosis has been implicated in the progression of disease in almost every physiological system and recent reports suggest a role for necroptosis in aging. Here, we present the first comprehensive analysis of age-related histopathological and immunological phenotypes in a cohort of Mlkl^-/- and Ripk3^-/- mice on a congenic C57BL/6 J genetic background. We show that genetic deletion of Mlkl in female mice interrupts immune system aging, specifically delaying the age-related reduction of circulating lymphocytes. -Seventeen-month-old Mlkl^-/- female mice were also protected against age-related chronic sterile inflammation in connective tissue and skeletal muscle relative to wild-type littermate controls, exhibiting a reduced number of immune cell infiltrates in these sites and fewer regenerating myocytes. These observations implicate MLKL in age-related sterile inflammation, suggesting a possible application for long-term anti-necroptotic therapy in humans.

Cognitive impairment in the immune-mediated inflammatory diseases compared with age-matched controls: Systematic review and meta-regression

OBJECTIVES

To compare the magnitude of cognitive impairment against age-expected levels across the immune mediated inflammatory diseases (IMIDs: systemic lupus erythematosus [SLE], rheumatoid arthritis [RA], axial spondyloarthritis [axSpA], psoriatic arthritis [PsA], psoriasis [PsO]).

METHODS

A pre-defined search strategy was implemented in Medline, Embase and Psychinfo on 29/05/2021. Inclusion criteria were: (i) observational studies of an IMID, (ii) healthy control comparison, (iii) measuring cognitive ability (overall, memory, complex attention/executive function, language/verbal fluency), and (iv) sufficient data for meta-analysis. Standardised mean differences (SMD) in cognitive assessments between IMIDs and controls were pooled using random-effects meta-analysis. IMIDs were compared using meta-regression.

RESULTS

In total, 65 IMID groups were included (SLE: 39, RA: 19, axSpA: 1, PsA: 2 PsO: 4), comprising 3141 people with IMIDs and 9333 controls. People with IMIDs had impairments in overall cognition (SMD: -0.57 [95% CI -0.70, -0.43]), complex attention/executive function (SMD -0.57 [95% CI -0.69, -0.44]), memory (SMD -0.55 [95% CI -0.68, -0.43]) and language/verbal fluency (SMD -0.51 [95% CI -0.68, -0.34]). People with RA and people with SLE had similar magnitudes of cognitive impairment in relation to age-expected levels. People with neuropsychiatric SLE had larger impairment in overall cognition compared with RA.

CONCLUSIONS

People with IMIDs have moderate impairments across a range of cognitive domains. People with RA and SLE have similar magnitudes of impairment against their respective age-expected levels, calling for greater recognition of cognitive impairment in both conditions. To further understand cognition in the IMIDs, more large-scale, longitudinal studies are needed.

Circulating Endothelial Progenitor Cells Reduce the Risk of Alzheimer's Disease

Cerebrovascular damage coexists with Alzheimer's disease (AD) pathology and increases AD risk. However, it is unclear whether endothelial progenitor cells reduce AD risk via cerebrovascular repair. By using the Framingham Heart Study (FHS) offspring cohort, which includes data on different progenitor cells, the incidence of AD dementia, peripheral and cerebrovascular pathologies, and genetic data (n = 1,566), we found that elevated numbers of circulating endothelial progenitor cells with CD34+CD133+ co-expressions had a dose-dependent association with decreased AD risk (HR = 0.67, 95% CI: 0.46-0.96, p = 0.03) after adjusting for age, sex, years of education, and APOE ε4. With stratification, this relationship was only significant among those individuals who had vascular pathologies, especially hypertension (HTN) and cerebral microbleeds (CMB), but not among those individuals who had neither peripheral nor central vascular pathologies. We applied a genome-wide association study (GWAS) and found that the number of CD34+CD133+ cells impacted AD risk depending on the homozygous genotypes of two genes: KIRREL3 rs580382 CC carriers (HR = 0.31, 95% CI: 0.17-0.57, p<0.001), KIRREL3 rs4144611 TT carriers (HR = 0.29, 95% CI: 0.15-0.57, p<0.001), and EXOC6B rs61619102 CC carriers (HR = 0.49, 95% CI: 0.31-0.75, p<0.001) after adjusting for confounders. In contrast, the relationship did not exist in their counterpart genotypes, e.g. KIRREL3 TT/CT or GG/GT carriers and EXOC6B GG/GC carriers. Our findings suggest that circulating CD34+CD133+ endothelial progenitor cells can be therapeutic in reducing AD risk in the presence of cerebrovascular pathology, especially in KIRREL3 and EXOC6B genotype carriers.

Rheumatoid Arthritis and Cognitive Impairment or Dementia: An Updated Review of Epidemiological Data

Rheumatoid arthritis (RA) is hypothesized to be associated with cognitive impairment and dementia, including Alzheimer's disease, through shared biological processes related to inflammation. It is important to elucidate this potential relationship as both conditions confer increased morbidity and even mortality among older adults. This narrative review provides a survey of recent epidemiologic studies, examining the association between rheumatoid arthritis and either dementia or cognitive impairment. Sixteen studies were included after searching in PubMed and EMBASE. All were published between 2012 and 2022 and were characterized as epidemiologic studies (either cohort, cross-sectional, or case-control). Studies varied in location, design, measures of exposure and outcome, and covariates considered. Of the 16 studies included, only five found statistically significant positive associations between RA and dementia or cognitive impairment. One study found an inverse relationship, while five studies found no associations at all. The remaining five studies found variable statistically significant associations between demographic or RA disease characteristics and cognitive measures. Given these mixed findings, further studies at both the mechanistic and population level are needed to clarify the possible shared biological underpinnings of these two conditions.

Can a basic solution activate the inflammatory reflex? A review of potential mechanisms, opportunities, and challenges

Stimulation of the inflammatory reflex (IR) is a promising strategy to treat systemic inflammatory disorders. However, this strategy is hindered by the cost and side effects of traditional IR activators. Recently, oral intake of sodium bicarbonate (NaHCO3) has been suggested to activate the IR, providing a safe and inexpensive alternative. Critically, the mechanisms whereby NaHCO3 might achieve this effect and more broadly the pathways underlying the IR remain poorly understood. Here, we argue that the recognition of NaHCO3 as a potential IR activator presents exciting clinical and research opportunities. To aid this quest, we provide an integrative review of our current knowledge of the neural and cellular pathways mediating the IR and discuss the status of physiological models of IR activation. From this vantage point, we derive testable hypotheses on potential mechanisms whereby NaHCO3 might stimulate the IR and compare NaHCO3 with classic IR activators. Elucidation of these mechanisms will help determine the therapeutic value of NaHCO3 as an IR activator and provide new insights into the IR circuitry.

A meta-analysis investigating the relationship between inflammation in autoimmune disease, elevated CRP, and the risk of dementia

Alzheimer's Disease (AD) represents the most common type of dementia and is becoming a steadily increasing challenge for health systems globally. Inflammation is developing as the main focus of research into Alzheimer's disease and has been demonstrated to be a major driver of the pathologies associated with AD. This evidence introduces an interesting research question, whether chronic inflammation due to pathologies such as inflammatory bowel disease (IBD) and rheumatoid arthritis (RA) could lead to a higher risk of developing dementia. In both IBD and RA, increased levels of the inflammatory biomarker C-reactive protein (CRP) can be highlighted, the latter being directly implicated in neuroinflammation and AD. In this meta-analysis both the association between chronic inflammatory diseases and elevated levels of CRP during midlife were investigated to examine if they correlated with an augmented risk of dementia. Moreover, the association between increased CRP and modifications in the permeability of the Blood Brain Barrier (BBB) in the presence of CRP is explored. The results displayed that the odds ratio for IBD and dementia was 1.91 [1.15-3.15], for RA it was 1.90 [1.09-3.32] following sensitivity analysis and for CRP it was 1.62 [1.22-2.15]. These results demonstrate a higher risk of dementia in patients presenting chronic inflammation and that exists an independent association with high CRP in midlife. This paper builds on published research that suggest a critical role for CRP both in stroke and AD and provides an analysis on currently published research on multiple diseases (IBD and RA) in which CRP is raised as well as chronically elevated. CRP and the associated risk of dementia and further research indicated that the monomeric form of CRP can infiltrate the BBB/be released from damaged micro-vessels to access the brain. This meta-analysis provides first-time evidence that chronic elevation of CRP in autoimmune diseases is directly associated with an increased risk of later development of Alzheimer's disease. Therefore, greater priority should be provided to the effective control of inflammation in patients with chronic inflammatory or autoimmune conditions and further long-term assessment of circulating CRP might inform of an individual's relative risk of developing dementia.

Association of Autoimmune Disorders and Disease-modifying Antirheumatic Drugs: (DMARDs) with the Risk of Alzheimer's and/or Dementia: A Population Study Using Medicare Beneficiary Data

OBJECTIVES

Alzheimer's disease (AD) and/or dementia is a prevalent neurocognitive disorder primarily affecting individuals over the age of 65. Identifying specific causes of AD and/or dementia can be challenging, with emerging evidence suggesting a potential association with autoimmune inflammatory conditions such as rheumatoid arthritis (RA). This study aimed to assess the prevalence rate of AD and/or dementia among Medicare beneficiaries reporting an autoimmune disorder. Additionally, this study sought to identify the comparative prevalence of AD and/or dementia in patients with an autoimmune disorder who were using disease-modifying antirheumatic drugs (DMARDs) compared to those not using DMARDs.

METHODS

Cross-sectional secondary data analyses were conducted on Medicare Current Beneficiary Survey (MCBS) data from 2017 and 2018. The MCBS data consists of a nationally representative sample of the Medicare population, a population that is largely 65 and older, and provides de-identified patient information. Patients from this dataset with a self-reported autoimmune disorder were included in the analyses. Descriptive analyses were conducted on demographic variables, chronic conditions, and medication use. The prevalence of AD and/or dementia was compared between patients with and without an autoimmune disorder. A backward stepwise selection regression was used to identify the risk factors associated with the prevalence of AD and/or dementia.

RESULTS

The study included 18,929 Medicare beneficiaries, with 4,405 identified as having one autoimmune disorder. The prevalence of AD and/or dementia was significantly higher in patients with an autoimmune disorder. The multivariate regression showed that RA was significantly associated with a higher risk of AD and/or dementia. Other demographic factors, including advanced age, African-American or Hispanic ethnicity, low body mass index, and chronic conditions of ischemic heart disease, history of myocardial infarction, history of stroke, depression, mental health disorder(s), and traumatic brain injury also showed statistically significant associations with AD and/or dementia. Patients using DMARDs demonstrated a reduced likelihood of having AD and/or dementia, compared to patients not using DMARDs.

CONCLUSION

This study provides evidence of an association between RA and increased risk of AD and/or dementia. The findings suggest that DMARD use may have a protective effect against the development of AD and/or dementia in patients with an autoimmune disorder.

Brain-Airway Interactions in Asthma

Asthma and brain interactions have long been appreciated and initially centered on increased anxiety and depression. Epidemiology studies have shown that early life stressors and situational disadvantages are risk factors for asthma. Conversely, the presence of asthma is a risk for mood and anxiety disorders, thus indicating a bidirectional effect between asthma and brain-related health. To substantiate asthma-brain interactions, validated instruments indicate and elucidate that communication likely exists between asthma and the brain. For example, provocation of an asthmatic response with an allergen challenge modulates how the brain responds to emotion-laden information. As detected by imaging studies, emotion-related brain activation is associated with generating airway inflammation. However, the specific mediators and processes mediating airway communication with the brain have yet to be established.Systemic inflammation is also associated with asthma and can affect other organ systems such as the cardiovascular system and the brain. Epidemiology studies have shown that asthma is a risk factor for dementia and Alzheimer's disease. In support of the importance of asthma as a risk factor for impaired cognitive function, imaging studies have shown changes to the white matter of the brain in asthma patients that resemble neuroinflammation changes seen in Alzheimer's disease and other neurodegenerative diseases. Therefore, bidirectional links between asthma and the brain exist with an important next research step to define asthma-brain interactions linked to neurodegeneration and dementia and explore whether treatments directed toward asthma-related inflammation can prevent the deleterious effects of asthma on brain health.

Prevalence of cognitive impairment in patients with rheumatoid arthritis: a cross sectional study

OBJECTIVE

To explore the role of chronic inflammation in rheumatoid arthritis (RA) on cognition.

METHODS AND ANALYSIS

Six hundred sixty-one men and women aged ≥55 years who fulfilled the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) criteria for RA were recruited from three healthcare trusts in the United Kingdom (UK) between May 2018 and March 2020. Study participants took part in interviews which captured sociodemographic information, followed by an assessment of cognition. RA specific clinical characteristics were obtained from hospital medical records. Participants were cognitively assessed using the Montreal Cognitive Assessment (MoCA) and were classified as cognitively impaired if they scored ≤27/30 points. Linear regression analyses were conducted to identify which demographic and clinical variables were potential predictors of cognitive impairment.

RESULTS

The average age of participants was 67.6 years and 67% (444/661) were women. 72% (458/634; 95% CI 0.69 to 0.76) of participants were classified as cognitively impaired (MoCA≤27). Greater cognitive impairment was associated with older age (p = .006), being male (p = .041) and higher disease activity score (DAS28) (with moderate (DAS28 > 3.1) (p = 0.008) and high (DAS28 > 5.1) (p = 0.008)) compared to those in remission (DAS28 ≤ 2.6). There was no association between MoCA score and education, disease duration, RF status, anti-cyclic citrullinated peptide (anti-CCP) status, RA medication type or use of glucocorticoids or non-steroidal anti-inflammatory drugs (p > 0.05).

CONCLUSION

This study suggests that cognitive impairment is highly prevalent in older adults with RA. This impairment appears to be associated with higher RA disease activity and supports the concept that chronic systemic inflammation might accelerate cognitive decline. This underlines the importance of controlling the inflammatory response.

Macrophages in health and disease

The heterogeneity of tissue macrophages, in health and in disease, has become increasingly transparent over the last decade. But with the plethora of data comes a natural need for organization and the design of a conceptual framework for how we can better understand the origins and functions of different macrophages. We propose that the ontogeny of a macrophage-beyond its fundamental derivation as either embryonically or bone marrow-derived, but rather inclusive of the course of its differentiation, amidst steady-state cues, disease-associated signals, and time-constitutes a critical piece of information about its contribution to homeostasis or the progression of disease.