Rheumatic diseases and autoimmune vascular dementia

Brain-targeting autoantibodies in patients with dementia

Autoantibodies against proteins in the brain are increasingly considered as a potential cause of cognitive decline, not only in subacute autoimmune encephalopathies but also in slowly progressing impairment of memory in patients with classical neurodegenerative dementias. In this retrospective cohort study of 161 well-characterized patients with different forms of dementia and 34 controls, we determined the prevalence of immunoglobulin (Ig) G and IgA autoantibodies to brain proteins using unbiased immunofluorescence staining of unfixed murine brain sections. Autoantibodies were detected in 21.1% of dementia patients and in 2.9% of gender-matched controls, with higher frequencies in vascular dementia (42%), Alzheimer's disease (30%), dementia of unknown cause (25%), and subjective cognitive impairment (16.7%). Underlying antigens involved glial fibrillary acidic protein (GFAP), glycine receptor, and Rho GTPase activating protein 26 (ARHGAP26), but also a range of yet undetermined epitopes on neurons, myelinated fiber tracts, choroid plexus, glial cells, and blood vessels. Antibody-positive patients were younger than antibody-negative patients but did not differ in the extent of cognitive impairment, epidemiological and clinical factors, or comorbidities. Further research is needed to understand the potential contribution to disease progression and symptomatology, and to determine the antigenic targets of dementia-associated autoantibodies.

Association of infertility and recurrent pregnancy loss with the risk of dementia

Emerging evidence has shown the association between female reproductive histories (e.g., menarche age, parity, premature and early menopause) and the risk of dementia. However, little attention has been given to infertility and pregnancy loss. To examine the associations of infertility, recurrent miscarriages, and stillbirth with the risk of dementia, this study used data from four cohorts in the International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events. Women with data on at least one of the reproductive exposures of interest, dementia, and all covariates were included. Histories of infertility, miscarriage, and stillbirth were self-reported. Dementia (including Alzheimer's disease) was identified through surveys, aged care, pharmaceutical, hospital, and death registry data. Cause-specific Cox regression models were used to estimate the hazard ratios of dementia, accounting for well-established risk factors of dementia, study variability, and within-study correlation. Overall, 291,055 women were included at a median (interquartile range) age of 55.0 (47.0-62.0) at baseline. During the median (interquartile range) follow-up period of 13.0 (12.0-14.0) years, 3334 (1.2%) women developed dementia. Compared to women without stillbirth, a history of recurrent stillbirths (≥ 2) was associated with 64% higher risk of dementia (adjusted hazard ratio = 1.64, 95% confidence interval: 1.46-1.85). Compared to women without miscarriage, women with recurrent miscarriages (≥ 3) were at 22% higher risk of dementia (adjusted hazard ratio = 1.22, 95% confidence interval: 1.19-1.25). These findings suggest that recurrent stillbirths is a risk factor for dementia and may need to be considered in risk assessment of dementia in women.

Novel insights into molecular signatures and pathogenic cell populations shared by systemic lupus erythematosus and vascular dementia

Although vascular dementia (VD) and systemic lupus erythematosus (SLE) may share immune-mediated pathophysiologic processes, the underlying mechanisms are unclear. This study investigated shared gene signatures in SLE versus VD, as well as their potential molecular mechanisms. Bulk RNA sequencing (RNAseq) and single-cell or single-nucleus RNAseq (sc/snRNAseq) datasets from SLE blood samples and VD brain samples were obtained from Gene Expression Omnibus. The identification of genes associated with both SLE and VD was performed using the weighted gene co-expression network analysis (WGCNA) and machine learning algorithms. For the sc/snRNAseq data, an unbiased clustering pipeline based on Seurat and CellChat was used to determine the cellular landscape profile and examine intracellular communication, respectively. The results were subsequently validated using a mice model of SLE with cognitive dysfunction (female MRL/lpr mice). WGCNA and machine learning identified C1QA, LY96, CD163, and MS4A4A as key genes for SLE and VD. sc/snRNAseq analyses revealed that CD163 and MS4A4A were upregulated in mononuclear phagocytes (MPs) from SLE and VD samples and were associated with monocyte-macrophage differentiation. Intriguingly, LGALS9-associated molecular pathway, as the only signaling pathway common between SLE and VD via CellChat analysis, exhibited significant upregulation in cortical microglia of MRL/lpr mice. Our analyses identified C1QA, LY96, CD163, and MS4A4A as potential biomarkers for SLE and VD. Moreover, the upregulation of CD163/MS4A4A and activation of LGALS9 signaling in MPs may contribute to the pathogenesis of VD with SLE. These findings offer novel insight into the mechanisms underlying VD in SLE patients.

Melatonin and Aging

The health problems associated with the aging process are becoming increasingly widespread due to the increase in mean life expectancy taking place globally. While decline of many organ functions is an unavoidable concomitant of senescence, these can be delayed or moderated by a range of factors. Among these are dietary changes and weight control, taking sufficient exercise, and the utilization of various micronutrients. The utility of incurring appropriate changes in lifestyle is generally not confined to a single organ system but has a broadly positive systemic effect.Among one of the most potent means of slowing down age-related changes is the use of melatonin, a widely distributed biological indole. While melatonin is well known as a treatment for insomnia, it has a wide range of beneficial qualities many of which are relevant. This overview describes how several of the properties of melatonin are especially relevant to many of the changes associated with senescence. Changes in functioning of the immune system are particularly marked in the aged, combining diminishing effectiveness with increasing ineffective and harmful activity. Melatonin treatment appears able to moderate and partially reverse this detrimental drift toward immune incompetence.

Inflammatory rheumatic diseases and the risk of Parkinson's disease: A systematic review and meta-analysis

BACKGROUND

Several studies showed inconsistencies in the relationships between inflammatory rheumatic diseases (IRDs) and the risk of Parkinson's disease (PD). Therefore, we carried out a meta-analysis to investigate the associations between different IRDs and PD risk.

METHODS

A comprehensive search was undertaken on PubMed, Embase, Cochrane Library, and Web of Science databases up to June 2022. Studies reporting the relationships between IRDs and PD risk were included. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated by using random-effects models.

RESULTS

Twenty-two publications covering seven IRDs containing data from 833,004 patients were identified for quantitative analysis. The pooled results indicated that ankylosing spondylitis (RR = 1.55, 95% CI: 1.31-1.83, I2 = 32.1%, P < 0.001), Sjögren's syndrome (RR = 1.34, 95% CI: 1.22-1.47, I2 = 58.5%, P < 0.001), and Behcet's disease (RR = 1.93, 95% CI: 1.07-3.49, I2 = 57.6%, P = 0.030) were associated with an increased PD risk. However, no significant associations were observed between gout, rheumatoid arthritis, systemic lupus erythematosus, as well as polymyalgia rheumatica and the subsequent development of PD.

CONCLUSION

Ankylosing spondylitis, Sjögren's syndrome, and Behcet's disease may increase PD risk.

Identification of potential drug targets for vascular dementia and carotid plaques by analyzing underlying molecular signatures shared by them

Background

Vascular dementia (VaD) and carotid atherosclerotic plaques are common in the elderly population, conferring a heavy burden on families and society. Accumulating evidence indicates carotid atherosclerotic plaques to be a risk factor for VaD. However, the underlying mechanisms for this association are mainly unknown.

Materials and methods

We analyzed temporal cortex gene expression data of the GSE122063 dataset and gene expression data of the GSE163154 dataset to identify commonly differentially expressed genes (DEGs). Then we performed functional enrichment analysis, immune cell infiltration and evaluation, correlation analysis between differentially expressed immune-related genes (DEIRGs) and immune cells, receiver operating characteristic (ROC) analysis, and drug-gene analysis.

Results

We identified 41 overlapped DEGs between the VaD and carotid atherosclerosis plaque datasets. Functional enrichment analyses revealed that these overlapped DEGs were mainly enriched in inflammatory and immune-related processes. Immunocyte infiltration and evaluation results showed that M0 macrophages, M2 macrophages, and T cells gamma delta had a dominant abundance in carotid atherosclerosis plaque samples, and M0 macrophages showed a significantly different infiltration percentage between the early and advanced stage plaques group. Resting CD4 memory T cells, M2 macrophages, and naive B cells were the top three highest infiltrating fractions in VaD. Furthermore, B cells and NK cells showed a different infiltration percentage between VaD and matched controls. We identified 12 DEIRGs, and the result of correlation analysis revealed that these DEIRGs were closely related to differentially expressed immune cells. We identified five key DEIRGs based on ROC analysis. The drug-gene interaction analysis showed that four drugs (avacopan, CCX354, BMS-817399, and ASK-8007) could be potential drugs for VaD and carotid atherosclerotic plaques treatment.

Conclusion

Collectively, these findings indicated that inflammatory and immune-related processes be a crucial common pathophysiological mechanism shared by VaD and carotid plaques. This study might provide new insights into common molecular mechanisms between VaD and carotid plaques and potential targets for the treatment.

Association between dementia and systemic rheumatic disease: A nationwide population-based study

Objectives

Systemic rheumatic disease is characterized by autoimmunity and systemic inflammation and affects multiple organs. Few studies have investigated whether autoimmune diseases increase the risk of dementia. Herein, we evaluate the relationship between systemic rheumatic disease and dementia through a population-based study using the Korean National Health Insurance Service (NHIS) claims database.

Methods

We conducted a nationwide population-based study using the Korean NHIS database, consisting of individuals who submitted medical claims from 2002–2013. Dementia was defined as having an acetylcholinesterase inhibitors (AChEIs) prescription along with symptoms satisfying the Alzhemier’s disease (AD) International Classification of Diseases (ICD)-10 codes (F00 or G30), or vascular dementia (VaD; ICD-10 or F01) criteria. Control subjects were matched to the dementia patients by age and sex. The study group was limited to those diagnosed with rheumatic disease at least 6 months prior to diagnosis of dementia. Rheumatic disease was defined by the following ICD-10 codes: Rheumatoid arthritis (RA: M05), Sjögren’s syndrome (SS: M35), systemic lupus erythematosus (SLE: M32), and Behcet’s disease (BD: M35.2).

Results

Of the 6,028 dementia patients, 261 (4.3%) had RA, 108 (1.6%) had SS, 12 (0.2%) had SLE, and 6 (0.1%) had BD. SLE history was significantly higher in dementia patients (0.2%) than in controls (0.1%) and was associated with dementia (odds ratio [OR], 2.48; 95% confidence interval [CI], 1.19–5.15). In subgroup analysis, SLE significantly increased dementia risk, regardless of dementia type (AD: OR, 2.29; 95% CI, 1.06–4.91; VaD: OR, 4.54; 95% CI, 1.36–15.14). However, these associations were not sustained in the mild CCI or elderly group.

Conclusion

SLE was independently associated with a higher risk of dementia, including AD and VaD when compared to the control group, even after adjustment. SLE patients (<65 years old) are a high-risk group for early vascular dementia and require screening for early detection and active prevention.

Association of cardiovascular disease and traditional cardiovascular risk factors with the incidence of dementia among patients with rheumatoid arthritis

OBJECTIVE

To determine the incidence of dementia in patients with rheumatoid arthritis (RA) 65 years and older, and compare the incidence of dementia in patients with RA with prevalent cardiovascular (CV) disease (CVD), CV risk factors but no prevalent CVD and neither (referent group).

METHODS

We analyzed claims data from the Center for Medicare & Medicaid Services (CMS) from 2006-2014. Eligibility criteria included continuous medical and pharmacy coverage for ≥ 12 months (baseline period 2006), > 2 RA diagnoses by a rheumatologist and at least 1 medication for RA. CVD and CV risk factors were identified using codes from the Chronic Condition Data Warehouse. Incident dementia was defined by 1 inpatient or 2 outpatient claims, or one dementia specific medication. Age-adjusted incident rates were calculated within each age strata. Univariate and multivariate Cox proportional hazard models were used to calculate Hazard Ratios (HR) and 95% confidence intervals.

RESULTS

Among 56,567 patients with RA, 11,789 (20.1%) incident cases of dementia were included in the main analysis. Age adjusted incident rates were high among all groups and increased with age. After adjustment for age, sex, comorbidities and baseline CV and RA medications, patients with CVD and CV risk factors between 65 and 74 years had an increased risk for incident dementia compared to those without CVD and without CV risk factors (HR 1.18 (95% CI 1.04-1.33) and HR 1.03 (95% CI 1.00-1.11), respectively). We observed a trend towards increased risk in patients between 75 and 84 years with CVD at baseline.

CONCLUSION

Patients with RA with both CVD and CV risk factors alone are at an increased risk for dementia compared to those with neither CVD nor CV risk factors; however, this risk is attenuated with increasing age. The impact of RA treatment and CV primary prevention strategies in the prevention of dementia in patients with RA warrants further studies.

[Mental disorders and cognitive impairment in patients with antiphospholipid syndrome]

Mental disorders (mainly anxiety and depressive disorders) and cognitive impairment are often found in patients with antiphospholipid syndrome (APS), but their prevalence, structure, and mechanisms of occurrence are not well researched. The review provides literature data on the frequency, spectrum and possible causes of mental disorders and cognitive impairment in patients with APS, the pathogenetic mechanisms of these disorders (in particular, the important role of antiphospholipid antibodies, stress factors, chronic inflammation), the relationship between APS, mental disorders and as well as cognitive impairment is examined. Special attention is paid to the influence of mental disorders and cognitive impairment on patients adherence to treatment, their quality of life, as well as the particularities of psychopharmacotherapy of mental disorders in patients with APS. The aim of the review is to actualize the interdisciplinary problem of mental disorders and cognitive impairment in patients with APS and the need to introduce a partnership model of care.

Prevalence of affective disorders and dementia in inflammatory polyarthropathies

Comorbid disorders are common in psychiatric diseases and understanding the risk of secondary diseases can aid successful clinical treatment. The objective of this study was to compare the frequency of comorbid dementia, affective disorders, and inflammatory polyarthropathies. Healthcare data obtained via the German Hospital Fees Act from two independent databases with more than 7.4 million cases were analyzed to compare the prevalence of comorbid disorders. Comorbid inflammatory polyarthropathy was observed in 2.27% of patients diagnosed with affective disorders and 1.35% of patients with dementia (p < 0.001). Among patients with a primary diagnosis of inflammatory polyarthropathy, 1.27% of patients were diagnosed with dementia, whereas 4.55% of age-matched patients without inflammatory polyarthropathies had comorbid dementia (p < 0.001). The opposite effect was demonstrated for affective disorders, as 5.77% of patients with a primary diagnosis of inflammatory polyarthropathy also had comorbid affective disorders, while 4.87% of age-matched patients without inflammatory polyarthropathy had an accompanying affective disease (p < 0.001). These findings show an association between the occurrence of inflammatory polyarthropathies, dementia, and affective disorders. This correlation might improve diagnosis and treatment for patients with comorbidities. Moreover, further exploration of the molecular pathophysiology underlying these relationships could be relevant for the development of novel treatment options.

Embelin Improves the Spatial Memory and Hippocampal Long-Term Potentiation in a Rat Model of Chronic Cerebral Hypoperfusion

Alzheimer's disease (AD) is the second most occurring neurological disorder after stroke and is associated with cerebral hypoperfusion, possibly contributing to cognitive impairment. In the present study, neuroprotective and anti-AD effects of embelin were evaluated in chronic cerebral hypoperfusion (CCH) rat model using permanent bilateral common carotid artery occlusion (BCCAO) method. Rats were administered with embelin at doses of 0.3, 0.6 or 1.2 mg/kg (i.p) on day 14 post-surgery and tested in Morris water maze (MWM) followed by electrophysiological recordings to access cognitive abilities and synaptic plasticity. The hippocampal brain regions were extracted for gene expression and neurotransmitters analysis. Treatment with embelin at the doses of 0.3 and 0.6 mg/kg significantly reversed the spatial memory impairment induced by CCH in rats. Embelin treatment has significantly protected synaptic plasticity impairment as assessed by hippocampal long-term potentiation (LTP) test. The mechanism of this study demonstrated that embelin treatment alleviated the decreased expression of BDNF, CREB1, APP, Mapt, SOD1 and NFκB mRNA levels caused by CCH rats. Furthermore, treatment with embelin demonstrated neuromodulatory activity by its ability to restore hippocampal neurotransmitters. Overall these data suggest that embelin improve memory and synaptic plasticity impairment in CCH rats and can be a potential drug candidate for neurodegenerative disease-related cognitive disorders.