Assessment of biocorrelates for brain involvement in female patients with rheumatoid arthritis

Does the presence of chronic pain affect scores on cognitive screening tests/brief cognitive measures for dementia? A systematic review and meta-analysis

OBJECTIVE

Cognitive screening tests can identify potential dementia by indicating a concerning level of cognitive impairment. The older populations for whom this is most relevant are more likely to experience chronic pain, which also impairs cognitive function, but pain's impact on cognitive screening tests specifically remains unknown.

METHOD

We conducted a systematic review and meta-analysis (SR/MA) following PRISMA guidelines evaluating cognitive screening scores in studies involving participants with chronic pain compared with a pain-free control group. Our question was whether the presence of chronic pain (self-reported or based on diagnosis) was associated with poorer performance on these screens, and to identify the heterogeneity across groups and screens.

RESULTS

The 51 studies identified yielded 62 effect size estimates. The pooled g was 0.76 (95% confidence interval 0.57 to 0.95). Heterogeneity was high for the full model (= 93.16%) with some reductions in sub-analyses. Around half of the studies were identified as being at a low risk of bias. There was no evidence of publication bias.

CONCLUSIONS

As a whole, this analysis suggests medium to large effect sizes on cognitive screen performance when people are living with chronic pain. We suggest that clinicians should consider the effect of chronic pain when cognitive screens are employed to investigate dementia. Further research could clarify the effect pain has on different screen sub-domains to aid their effective use with these populations.

Prevalence of neurocognitive impairment in patients with rheumatoid arthritis - a systematic review and meta-analysis

ObjectiveThis study aimed to evaluate prevalence rates (PRs) of neurocognitive impairment and its potential moderators among patients with rheumatoid arthritis (RA). MethodA systematic review of the available literature and data extraction was undertaken on 6 August 2021, with the update by 14 September 2023, by two reviewers independently. Literature was screened for reported rates of prevalence of neurocognitive impairment in RA patients. The meta-analysis was performed using RStudio with the "meta" library. ResultsTwenty-two studies that fulfilled all selection criteria were carefully analyzed. The PR of neurocognitive impairment was 0.49 [0.38-0.61] across all studies included in the review; 0.75 [0.54-0.88] for the MoCA; 0.56 [0.40-0.72] for the MMSE; and 0.26 [0.16-0.38] for comprehensive batteries. The meta-regression results indicated that, depending on the measurement method, the percentage of subjects with positive rheumatoid factor, women ratio, mean age of participants, mean duration of RA, and percentage of domains that had to be impaired to diagnose neurocognitive impairment turned out to be statistically significant moderators. ConclusionsNeurocognitive impairment is a clinically relevant condition in many RA patients, and its prevalence is alarming high.

The clinical features and potential mechanisms of cognitive disorders in peripheral autoimmune and inflammatory diseases

According to a study from World Health Organization's Global Burden of Disease, mental and neurological disorders have accounted for 13% of global diseases in recent years and are on the rise. Neuropsychiatric conditions or neuroinflammatory disorders are linked by the presence of an exaggerated immune response both peripherally and in the central nervous system (CNS). Cognitive dysfunction (CD) encompasses a complex group of diseases and has frequently been described in the field of autoimmune diseases, especially in multiple non-CNS-related autoimmune diseases. Recent studies have provided various hypotheses regarding the occurrence of cognitive impairment in autoimmune diseases, including that abnormally activated immune cells can disrupt the integrity of the blood-brain barrier (BBB) to trigger a central neuroinflammatory response. When the BBB is intact, autoantibodies and pro-inflammatory molecules in peripheral circulation can enter the brain to activate microglia, inducing CNS inflammation and CD. However, the mechanisms explaining the association between the immune system and neural function and their contribution to diseases are uncertain. In this review, we used clinical statistics to illustrate the correlation between CD and autoimmune diseases that do not directly affect the CNS, summarized the clinical features and mechanisms by which autoimmune diseases trigger cognitive impairment, and explored existing knowledge regarding the link between CD and autoimmune diseases from the perspective of the field of neuroimmunology.

Causality between rheumatoid arthritis and the risk of cognitive impairment: a Mendelian randomization study

BACKGROUND

There is mounting proof that rheumatoid arthritis (RA) and cognitive decline are related. These studies, however, have not all been uniform, and others have not discovered such a correlation. It is essential to investigate the link between RA and cognitive decline.

METHOD

We conducted a Mendelian randomization analysis utilizing three different publicly accessible RA GWAS summary datasets and a variety of meticulously verified instrumental variables. We mostly used inverse variance weighting (IVW), as well as MR-Egger, weighted median, MR-PRESSO, and several sensitivity analyses, to figure out the link between RA and cognitive impairment (CI).

RESULTS

Our MR study identified the causality between RA and declining cognitive performance (β = - 0.010, 95% CI of - 0.017 to - 0.003, P = 4.33E-03) and cognitive function (β = - 0.029, 95% CI of - 0.053 to - 0.005, P = 1.93E-02). The consistent direction of the connection is revealed by sensitivity analysis utilizing the weighted median and the MR-Egger method. Furthermore, we reproduced our findings across two additional RA datasets and found identical outcomes, strengthening the validity of our findings.

CONCLUSION

This study offers proof of causality between RA and an increased risk of CI. Our findings highlight the importance of examining RA patients for cognitive ability, which may open up fresh ideas for the prevention of CI.

Cognitive Dysfunction Biomarkers in Patients With Rheumatoid Arthritis: A Systematic Review

BACKGROUND/OBJECTIVES

During the last years, a growing number of studies have investigated the link between cognitive dysfunction and rheumatoid arthritis (RA), highlighting the potential pathogenic role of several clinical, psychological, and biological factors. We aimed to investigate serological and cerebrospinal fluid biomarkers in humans and its association with cognitive dysfunction in patients with RA.

METHODS

We performed a systematic review using PRISMA (Preferred Reported Items for Systematic Reviews and Meta-analysis) protocol. A systematic search was conducted in the PubMed/MEDLINE, EMBASE, LILACS, Scopus, and Google Scholar databases from inception up to November 2021. The inclusion criteria for studies were defined based on the participants involved, type of exposure, type of comparison group, outcome of interest, and study design.

RESULTS

Five original studies were included, which provided data from 428 participants. Among plasma proteins, SHH was increased and TTR was reduced in patients with mild cognitive impairment; anti-myelin basic protein and anti-myelin oligodendrocyte glycoprotein negatively correlated with memory, executive function, and attention. S100β negatively correlated with memory and executive functions; some lymphocyte subpopulations positively correlated with attention, memory, and executive functions. Interleukin 2 [IL-2], IL-4, IL-6, and tumor necrosis factor α negatively correlated with memory and positively correlated with executive functions. Interleukin 1β negatively correlated with global cognitive dysfunction and positively correlated with logical thinking. Interleukin 10 and brain-derived neurotrophic factor negatively correlated with memory.

CONCLUSION

Despite the relative scarcity of studies on this subject and the heterogeneity of results, we identified possible biomarkers for cognitive deficits in the RA population. Further longitudinal studies are warranted to clarify these associations and the establishment of possible biomarkers for cognitive deficits in RA.

Longitudinal Study of Cognitive Functioning in Adults with Juvenile Idiopathic Arthritis

Objective: To prospectively evaluate possible decline of cognitive functions in adult patients with juvenile idiopathic arthritis (JIA) and identify associated factors. Patients and methods: We performed a 24-month prospective observational study of adults (≥16 years) with JIA. The primary outcome measure was decline in cognitive function defined as a worsening of ≥2 points on the scales of the subsets administered to evaluate the different cognitive areas using the Wechsler Adult Intelligence Scale (WAIS) after 24 months: attention/concentration (digit span); verbal function (vocabulary); visual-spatial organization (block design); working memory (letter-number sequencing); and problem solving (similarities). Other variables included average inflammatory activity using C-reactive protein and composite activity indexes, comorbidity, and treatment. Logistic regression was performed to identify factors associated with cognitive decline. Results: The study population comprised 52 patients with JIA. Of these, 15 (28.8%) had cognitive decline at V24. The most affected functions were working memory (17.3%), attention/concentration (9.6%), verbal function (7.7%), visual-spatial organization (7.7%), and problem solving (3.8%). There were no significant differences in the median direct or scale scores for the cognitive functions evaluated between V0 and V24 for the whole sample. The factors associated with cognitive decline in patients with JIA were average C-reactive protein (OR [95% CI], 1.377 [1.060–1.921]; p = 0.039), depression (OR [95% CI], 3.691 [1.294–10.534]; p = 0.015), and treatment with biologics (OR [95% CI], 0.188 [0.039–0.998]; p = 0.046). Conclusion: Cognitive decline was detected in almost one third of adults with JIA after 24 months of follow-up. Systemic inflammatory activity in JIA patients was related to cognitive decline. Patients treated with biologics had a lower risk of decline in cognitive functions.

Diffusion tensor imaging analysis of rheumatoid arthritis patients with neuropsychiatric features to determine the alteration of white matter integrity due to vascular events

INTRODUCTION

The pathophysiology of neuropsychiatric manifestations in rheumatoid arthritis is not well known. The magnetic resonance imaging of the brain in rheumatoid arthritis demonstrates non-specific findings, and in the majority of cases, magnetic resonance imaging fails to detect an abnormality, even in rheumatoid arthritis patients with neuropsychiatric manifestations. Therefore, we aimed to assess microstructural integrity changes of white matter in patients with rheumatoid arthritis by using different diffusion tensor imaging parameters.

METHODS

Eighteen rheumatoid arthritis patients (10 with neuropsychiatric symptoms and 8 without any neuropsychiatric symptoms) and 14 controls were included. The volume of the T2 hyperintense lesions was assessed. Different diffusion tensor imaging parameters such as fractional anisotropy, apparent diffusion coefficient, trace, axial diffusivity, and radial diffusivity were obtained from six different regions of white matter. Inter group significant difference was determined by one-way analysis of variance followed by Tukey's post hoc test. The accuracy of diffusion tensor imaging matrices was evaluated from the receiver operating characteristic curve.

RESULTS

No significant difference in lesions' volume was detected between rheumatoid arthritis patients with or without neuropsychiatric symptoms. There was an increased apparent diffusion coefficient and radial diffusivity (p < 0.05) as well as decreased fractional anisotropy and axial diffusivity (p < 0.5) in rheumatoid arthritis patients with neuropsychiatric symptoms compared to controls. Moreover, the apparent diffusion coefficient (p < .05) was increased in both positive and negative MRI of patients with neuropsychiatric features compared to the control group. The sensitivity and specificity of the apparent diffusion coefficient parameters was 73% and 72%, respectively.

CONCLUSIONS

The various anisotropic metrics were altered in rheumatoid arthritis patients with neuropsychiatric symptoms by using diffusion tensor imaging analysis, representing that central nervous system vasculitis leads to tissue hypoxia resulting in vasogenic edema. This may lead to axonal and myelin degeneration of white matter fibers and neuronal cell disruption. Key Points • Our study confirms that neurovascular events are not uncommon in RA patients with NP features. Diffusion tensor imaging (DTI) is superior to conventional MRI scan for RA patients with NP features because it distinguishes between gray and white matter structures. • RA patients with NP features are more likely to have microstructural changes detected by DTI than by DWI, and it can provide comprehensive anatomical layouts describing regional disparities in neurodegeneration. • DTI's quantitative association of NP symptoms in a large patient cohort is an important study scope.

Cognitive impairment in patients with rheumatoid arthritis: A systematic review and meta-analysis

OBJECTIVE

An increasing number of studies have demonstrated cognitive impairment in patients with rheumatoid arthritis (RA). The literature indicates many factors play an important role in this clinical problem, such as the severity of depressive symptoms and the treatment used. The aim of this study was to systematically review studies comparing cognitive functioning between healthy participants and RA patients and to determine both the severity and potential moderators of cognitive impairment.

METHODS

For this purpose, 16 studies that fulfilled all selection criteria were carefully selected. Altogether, 921 patients with RA (812 women and 109 men) and 700 controls participated in these studies. Due to the inability to perform a network meta-analysis, it was decided to determine the effect sizes for studies which used the same measurement methods.

RESULTS

The analysis demonstrated greater impairment of cognitive functioning in patients with RA than in healthy controls, with effect sizes ranging from small to large, depending on the assessment method used in the study.

CONCLUSIONS

The study pinpoints potential biases, lack of replication, and inconsistencies in reporting data as possible confounding factors and suggests further recommendations for assessment methods, research directions and clinical implications.

CLINICAL TRIAL REGISTRATION

Not applicable.

Cognitive Decline in Rheumatoid Arthritis: Insight into the Molecular Pathogenetic Mechanisms

Cognitive decline refers to a deterioration of intellectual and learning abilities and related memory problems, and is often associated with behavioral alterations, which prevents sufferers from carrying out the most common daily activities, such as maintaining normal productive interpersonal relationships, communicating, and leading an autonomous life. Numerous studies have highlighted the association between cognitive decline and autoimmune disorders, including rheumatoid arthritis (RA). RA is a chronic, inflammatory, autoimmune disease that involves systems and organs other than the bones and joints, with varying severity among patients. Here, we review the studies investigating the link between cognitive decline and RA, focusing on the main molecular pathogenetic mechanisms involved. The emerging body of data suggests that clinical, psychological, and biological factors may contribute to the pathogenesis of cognitive decline in RA, including cardiovascular complications, chronic pain, depression, inflammatory factors, changes in hormone levels, drug side effects, and genetics. Further studies are warranted in order to fully clarify the basis underlying the association between cognitive decline and RA and to find new possible diagnostic strategies and therapeutic targets for RA patients.

Neuronal Correlates of Cognitive Control Are Altered in Women With Endometriosis and Chronic Pelvic Pain

Endometriosis is a debilitating women's health condition and is the most common cause of chronic pelvic pain. Impaired cognitive control is common in chronic pain conditions, however, it has not yet been investigated in endometriosis. The aim of this study was to explore the neuronal correlates of cognitive control in women with endometriosis. Using a cross-sectional study design with data collected at a single time-point, event-related potentials were elicited during a cued continuous performance test from 20 women with endometriosis (mean age = 28.5 ± 5.2 years) and 20 age- and gender-matched controls (mean age = 28.5 ± 5.2 years). Event-related potential components were extracted and P3 component amplitudes were derived with temporal principal components analysis. Behavioral and ERP outcomes were compared between groups and subjective pain severity was correlated with ERP component amplitudes. No significant behavioral differences were seen in task performance between the groups (all p > 0.094). Target P3b (all p < 0.034) and SW (all p < 0.040), and non-target early P3a (eP3a; all p < 0.023) and late P3a (lP3a; all p < 0.035) amplitudes were smaller for the endometriosis compared to the healthy control group. Lower non-target eP3a (p < 0.001), lP3a (p = 0.013), and SW (p = 0.019) amplitudes were correlated with higher pain severity scores. Findings suggest that endometriosis-associated chronic pelvic pain is linked to alterations in stimulus-response processing and inhibitory control networks, but not impaired behavioral performance, due to compensatory neuroplastic changes in overlapping cognitive control and pain networks.

The Link Between Autonomic Nervous System and Rheumatoid Arthritis: From Bench to Bedside

Neuronal stimulation is an emerging field of research focused on the management and treatment of various diseases through the reestablishment of physiological homeostasis. Electrical vagus nerve stimulation has recently been proposed as a revolutionary therapeutic option for rheumatoid arthritis (RA) in combination with or even as a replacement for conventional and biological drugs. In the past few years, disruption of the autonomic system has been linked to RA onset and activity. Novel research on the link between the autonomic nervous system and the immune system (immune-autonomics) has paved the way for the development of innovative RA management strategies. Clinical evidence supports this approach. Cardiovascular involvement, in terms of reduced baroreflex sensitivity and heart rate variability-derived indices, and mood disorders, common comorbidities in patients with RA, have been linked to autonomic nervous system dysfunction, which in turn is influenced by increased levels of circulating pro-inflammatory cytokines. This narrative review provides an overview of the autonomic nervous system and RA connection, discussing most of the common cardiac and mental health-related RA comorbidities and their potential relationships to systemic and joint inflammation.

Evaluation of cognitive function in adult patients with juvenile idiopathic arthritis

OBJECTIVE

To evaluate cognitive function in adult patients with juvenile idiopathic arthritis (JIA) and associated factors.

PATIENTS AND METHODS

We performed a cross-sectional observational study of adult patients with JIA and a healthy control group (no inflammatory diseases) matched for age, gender, and educational level. Cognitive function was assessed using Wechsler Adult Intelligence Scale-III. The cognitive domains measured were attention/concentration, verbal function, visuospatial organization, working memory, and problem solving (Similarities). Other measures included clinical-epidemiological characteristics, comorbid conditions, and treatment. We performed a descriptive bivariate analysis and logistic regression to identify factors associated with visuospatial involvement.

RESULTS

The study population comprised 104 subjects (52 with JIA and 52 healthy controls). Patients with JIA had poorer results for visuospatial function, with a lower median scaled score on the Block Design test (5.0 [4.0-8.0] vs 8.0 [5.0-10.0]; P = .014). The number of patients with scaled scores below the average range (<8) in visuospatial organization was significantly greater in the JIA group (67.3% vs 40.4%; P = .006). The multivariate analysis revealed time since diagnosis (odds ratio [95% CI], 1.03 [1.01-1.06]), inflammatory activity according to Juvenile Arthritis Disease Activity Score 27-joint count (1.94 [1.01-3.75]), and educational level (0.28 [0.08-0.94]) to be factors associated with visuospatial function.

CONCLUSION

Cognitive function in adult patients with JIA is poorer than in healthy controls at the expense of visuospatial function. Visuospatial function in JIA patients was inversely associated with disease duration, inflammatory activity, and lower educational level.

The interplay between immunosenescence and age-related diseases

The aging immune system (immunosenescence) has been implicated with increased morbidity and mortality in the elderly. Of note, T cell aging and low-grade inflammation (inflammaging) are implicated with several age-related conditions. The expansion of late-differentiated T cells (CD28⁻), regulatory T cells, increased serum levels of autoantibodies, and pro-inflammatory cytokines were implicated with morbidities during aging. Features of accelerated immunosenescence can be identified in adults with chronic inflammatory conditions, such as rheumatoid arthritis, and are predictive of poor clinical outcomes. Therefore, there is an interplay between immunosenescence and age-related diseases. In this review, we discuss how the aging immune system may contribute to the development and clinical course of age-related diseases such as neurodegenerative diseases, rheumatoid arthritis, cancer, cardiovascular, and metabolic diseases.

Accelerated immunosenescence in rheumatoid arthritis: impact on clinical progression

Patients with rheumatoid arthritis (RA) develop features of accelerated ageing, including immunosenescence. These changes include decreased thymic functionality, expansion of late-differentiated effector T cells, increased telomeric attrition, and excessive production of cytokines (senescence-associated secretory phenotype). The progression of RA has been associated with the early development of age-related co-morbidities, including osteoporosis, cardiovascular complications, and cognitive impairment. Here I review data supporting the hypothesis that immune-senescence contributes to the aggravation of both articular and extra-articular manifestations. Of note, poor cognitive functions in RA were associated with senescent CD28- T cells, inflammaging, and autoantibodies against brain antigens. The pathways of immune-to-brain communication are discussed and provide the rationale for the cognitive impairment reported in RA.

Extracellular Vesicles from Hyperammonemic Rats Induce Neuroinflammation and Motor Incoordination in Control Rats

Minimal hepatic encephalopathy is associated with changes in the peripheral immune system which are transferred to the brain, leading to neuroinflammation and thus to cognitive and motor impairment. Mechanisms by which changes in the immune system induce cerebral alterations remain unclear. Extracellular vesicles (EVs) seem to play a role in this process in certain pathologies. The aim of this work was to assess whether EVs play a role in the induction of neuroinflammation in cerebellum and motor incoordination by chronic hyperammonemia. We characterized the differences in protein cargo of EVs from plasma of hyperammonemic and control rats by proteomics and Western blot. We assessed whether injection of EVs from hyperammonemic to normal rats induces changes in neuroinflammation in cerebellum and motor incoordination similar to those exhibited by hyperammonemic rats. We found that hyperammonemia increases EVs amount and alters their protein cargo. Differentially expressed proteins are mainly associated with immune system processes. Injected EVs enter Purkinje neurons and microglia. Injection of EVs from hyperammonemic, but not from control rats, induces motor incoordination, which is mediated by neuroinflammation, microglia and astrocytes activation and increased IL-1β, TNFα, its receptor TNFR1, NF-κB in microglia, glutaminase I, and GAT3 in cerebellum. Plasma EVs from hyperammonemic rats carry molecules necessary and sufficient to trigger neuroinflammation in cerebellum and the mechanisms leading to motor incoordination.

Central nervous system involvement in rheumatoid arthritis: possible role of chronic inflammation and tnf blocker therapy

Rheumatoid arthritis (RA) is a chronic disease, the etiology of which has yet to be clarified, which causes activation of proinflammatory pathways that bring about joint and systemic inflammation. Although peripheral nervous system anomalies are observed widely in RA, very few case reports on changes in the central nervous system (CNS) have been published. In recent years, the pathophysiology of CNS involvement that can occur in RA has attracted a great deal of attention. Emphasis has focused on the possibility that CNS involvement occurs due to blood-brain barrier (BBB) damage associated with chronic inflammation. The present study was performed to investigate the possible effects of BBB dysfunction and tumor necrosis factor (TNF) blocker therapy on BBB function, which may cause CNS damage in patients with RA. 58 RA patients [47 (81.0%) females, 11 (19.0%) males] and 34 healthy controls [24 (70.6%) females, 10 (29.4%) males] were included in the study. All RA patients were on synthetic DMARD therapy at the beginning. Thirty patients continued DMARD therapy, and 28 patients with high disease activity were started on TNF blocker therapy. All demographic characteristics of the patients were recorded. Disease activity was evaluated using the Disease Activity Score 28-joint count C reactive protein. The Mini-Mental State Examination was used to evaluate cognitive function, and the Fazekas scale was used to assess cranial lesions visualized by magnetic resonance imaging (MRI). Patients' peripheral blood S100β, glial fibrillary acidic protein (GFAP), claudin, interleukin (IL)-17, and IL-1β levels were measured at the beginning of the study and after 6 months. Demographic characteristics (including sex, age, and body mass index) were similar in the RA and control groups. S100β and GFAP levels were significantly higher in the patient group than in the control group. In the group that was started on TNF blocker therapy, S100β and GFAP levels were significantly decreased 6 months after commencement of treatment. No difference was observed between the RA and control groups in terms of hyperintense lesions seen on cranial MRI. The S100β levels increased with lesions in the deep white matter seen on cranial MRI in patients with RA. In conclusion, next to decreasing disease activity and joint erosions by suppressing inflammation, anti-TNF therapy in RA can also suppress potential CNS involvement linked to BBB (blood-brain barrier) dysfunction. Further studies with broader participation and longer patient follow-up are needed to reinforce this hypothesis.

Unusual Cerebral Involvement of Rheumatoid Arthritis Mimicking a Tumor

BACKGROUND

The central nervous system's involvement in Rheumatoid Arthritis (RA) is infrequent and can be life-threatening. Mass-like CNS involvement is an unusual presentation. A 45 year old man had suffered seropositive rheumatoid arthritis for five years referred to our hospital with one-week history of right-sided facial paralysis, left hemiparesis and headache.

DISCUSSION

MRI demonstrated hyperintense mass-like lesion extended from mesencephalon to right hippocampus and basal ganglia on T2 and FLAIR images. On DWI, restricted diffusion was not present. After contrast administration, minimal contrast enhancement was noted. After methotrexate and steroid treatment, the size had been markedly shrunken on the follow-up images. The clinical symptoms were also improved.

CONCLUSION

To our knowledge, the mass-like presentation was not reported in the literature. We report an unusual case of brain involvement of rheumatoid arthritis mimicked tumor.

Fatigue in IBD: epidemiology, pathophysiology and management

Fatigue is an important clinical problem in patients with IBD, affecting nearly 50% of patients in clinical remission and > 80% of those with active disease. The resulting decrease in quality of life and impaired work productivity and functioning contribute markedly to the societal costs of fatigue. However, despite the burden and effects of fatigue, little is known about its aetiology and pathophysiology, which impairs our ability to effectively treat this symptom. Here, we review the theories behind the development of fatigue in IBD and the role of contributing factors, including nutritional deficiency, inflammation and altered metabolism. We also explore the potential role of the gut microbiome in mediating fatigue and other psychological symptoms through the gut-brain axis. We discuss the efficacy of nutrient repletion and various psychological and pharmacological interventions on relieving fatigue in patients with IBD and expand the discussion to non-IBD-related fatigue when evidence exists. Finally, we present a therapeutic strategy for the management of fatigue in IBD and call for further mechanistic and clinical research into this poorly studied symptom.

Proteomic analysis of plasma from rheumatoid arthritis patients with mild cognitive impairment

Rheumatoid arthritis (RA) patients may suffer from comorbid neuropsychiatric symptoms including mild cognitive impairment (MCI). Although comorbidity of MCI is common, there are currently no validated plasma biomarkers to aid MCI diagnosis. This study screened plasma from patients with RA with and without comorbid MCI to identify potential biomarkers useful in the differential diagnosis of comorbid MCI. Plasma samples were collected from patients with RA without comorbid MCI, with comorbid MCI, and from healthy controls. Plasma samples were examined by tandem mass tags (TMT) combined with two-dimensional liquid chromatography-tandem mass spectrometry (2D-LC-MSMS) to analyze protein expression. Differentially expressed proteins were identified by bioinformatics and validated by enzyme-linked immunosorbent assay (ELISA). A total of 746 reliable proteins and 158 differentially expressed proteins were identified. Fourteen patients with RA-MCI showed differential protein expression (six proteins upregulated and eight proteins downregulated) compared with those patients without MCI and with healthy controls. Bioinformatics analysis showed that the differentially expressed proteins were primarily involved in biological processes, such as cell adhesion, coagulation, apoptosis, and body fluid regulation. The results of the ELISA experiments, similar to those of the proteomic analysis, demonstrated that sonic hedgehog (SHH) was upregulated and serum paraoxonase (TTR) was downregulated in patients with RA-MCI. These results indicate that SHH and TTR may be candidate plasma biomarkers that could be used to distinguish patients with RA and comorbid MCI from those without comorbid MCI.

Cognitive impairment in rheumatoid arthritis: role of lymphocyte subsets, cytokines and neurotrophic factors

To what extent the cognitive impairment of rheumatoid arthritis (RA) is modulated by autoimmune and/or inflammatory activity is largely unknown. The aim of this study was to investigate the role of peripheral inflammation on cognitive functions of patients with active (Ac-), controlled (Co-) RA and healthy controls. In a cross-sectional study, 102 RA patients and 30 matched healthy controls were recruited. B and T cell subsets were immunophenotyped by flow cytometry. Plasma cytokines and neurotrophins were measured by flow cytometry and ELISA, respectively. Cognitive performance, depression and stress were evaluated by structured clinical interviews. Generalized linear modeling (GzLM) was used to compare differences between groups and multiple linear regression models were used to explore the predictive value of immune variables on cognitive performance. RA patients had overall cognitive impairment. Of note, the Ac-RA had the poorest performance on digit span (DST) and N-back when compared to Co-RA and control group (DST 9.9 ± 2.1, 12.9 ± 4.2, 15.5 ± 4.7, respectively; N-back 49.2 ± 8.3, 55.5 ± 11.1, 60.8 ± 9.1, respectively, all p < 0.0001). RA patients had expansions of immature B cells (Ac-RA 11.2 ± 7.1, Co-RA: 9 ± 5.7, control 5.9 ± 2.1) and plasma cells (Ac-RA 5.2 ± 2.5, Co-RA 6.9 ± 3.7, control 2.8 ± 1.7) as compared to controls, all p < 0.05. RA patients (controlled and active disease) had higher plasma levels of TNF, IL-2, IL-4, IL-6 and IL-10 than controls (all p < 0.002). RA patients had higher BDNF levels (Ac-RA 17,354.4 ± 5357.3, Co-RA 13,841.2 ± 5953.7, control 11,543.3 ± 3772), but lower GDNF levels [median (interquartile range) Ac-RA 0 pg/ml (0.0), Co-RA 0 pg/ml (4.6) and control 4.7 pg/ml (18.1)] than controls (all p < 0.05). RA patients had global cognitive impairment, which was associated with disease activity and immune changes.

Gulf War illness (GWI) as a neuroimmune disease

Gulf War illness (GWI) is a chronic disease characterized by the involvement of several organs, including the brain (Christova et al., Exp Brain Res doi: 10.1007/s00221-017-5010-8 , 2017). In a previous study (Georgopoulos et al., J Neural Eng 4:349-355, 2015), we identified six protective alleles from Class II human leukocyte antigen (HLA) genes, and more recently, we investigated the brain correlates of this protection (James et al., EBioMedicine 13:72-79, 2016). Those and other studies (Israeli, Lupus, 21:190-194, 2012) suggested an involvement of the immune system in GWI. In a recent study (Engdahl et al., EBioMedicine doi: 10.1016/j.ebiom.2016.08.030 , 2016), we showed that the brain pattern of synchronous neural interactions (SNI; Georgopoulos et al., J Neural Eng 4:349-355, 2007) in GWI is distinctly different from that in healthy controls. Here we focused on the SNI itself, as a basic measure of neural communication (irrespective of specific connections) and compared it between GWI and seven other diseases that cover a broad spectrum of etiology and pathophysiology. Specifically, we sought to determine which, if any, of those diseases might resemble GWI SNI, overall and within the HLA protective domain, and thus gain further knowledge regarding the nature of GWI brain abnormality. We studied a total of 962 participants from a healthy control population (N = 583) and eight different diseases, including GWI (N = 40), schizophrenia (SZ; N = 21), Alzheimer's disease (AD; N = 66), posttraumatic stress disorder (PTSD; N = 159), major depressive disorder (MDD; N = 10), relapsing-remitting multiple sclerosis (RRMS; N = 43), Sjögren's syndrome (SS; N = 32), and rheumatoid arthritis (RA; N = 8). They all underwent a resting-state magnetoencephalographic (MEG) scan to calculate SNIs. Data were analyzed using analysis of covariance (ANCOVA) with disease as fixed factor, and sex and age as covariates. We found that GWI SNIs differed significantly from control SZ, AD, PTSD and MDD but not from RRMS, SS and RA. In addition, we compared GWI to RRMS, SS and RA with respect to SNIs of MEG sensor pairs that were related to the HLA alleles protective for GWI (James et al., EBioMedicine 13:72-79, 2016). We found that GWI SNIs did not differ significantly from any of these three diseases but they did so from control SZ, AD, PTSD and MDD. These findings indicate that (a) GWI brain synchronicity does not differ significantly from that of known immune-related diseases (RRMS, SS, RA), and (b) that this SNI similarity is present within the HLA-related SNIs. In contrast, GWI SNIs differed significantly from those of the other diseases. We conclude that altered brain communication in GWI likely reflects immune-related processes, as postulated previously (James et al., EBioMedicine 13:72-79, 2016). By extension, these findings also indicate that functional brain abnormalities in RRMS, SS and RA might be, in part, due to lack of protective HLA alleles as documented for GWI (Georgopoulos et al., EBioMedicine 3:79-85, 2015).

Autoantibodies against myelin sheath and S100β are associated with cognitive dysfunction in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) has been associated with cognitive impairment and peripheral production of autoantibodies. Autoantibodies against central nervous system (CNS) proteins and S100 calcium-binding β (S100β) were found increased in diseases characterized by cognitive impairment like Alzheimer disease and Neuropsychiatric Systemic Lupus Erythematosus (NPSLE). The aim of this study was to investigate the plasma levels of autoantibodies against myelin basic protein (anti-MBP), myelin oligodendrocyte glycoprotein (anti-MOG) and S100β, and their relationships with cognitive performance in RA patients. Twenty patients with active rheumatoid arthritis and 19 age-, sex-, and schooling-matched healthy controls were recruited. Multiple dimensions of cognitive function were evaluated by structured clinical questionnaires. Autoantibodies and S100β levels were assessed by ELISAs. Patients had significantly higher levels of anti-MBP IgG (17.51 ± 1.36 vs. 5.24 ± 0.53 ng/mL), anti-MOG IgG (5.68 ± 1.34 vs. 0.51 ± 0.49 ng/mL), and S100β protein (2.24 ± 0.50 vs. 0.47 ± 0.06) than controls (all p < 0.0001). After adjusting for potential confounders, RA group presented worse cognitive performance involving the working memory and executive functions such as inhibition, flexibility, and mental control in parallel to higher autoantibodies and S100β levels than healthy controls (all p < 0.001). Levels of anti-MBP were negatively associated with delayed verbal recall (DVR; r = -0.42, p = 0.005), Stroop Color-Word (r = -0.48, p = 0.004), and N-Back Total scores (r = -0.59, p < 0.0001) and positively with Trail Making Test B (TMB, r = 0.53, p = 0.001). Negative correlation was found between levels of anti-MOG and DVR (r = -0.64, p < 0.0001), N-Back Total scores (r = -0.35, p = 0.03), Stroop Color-Word (r = -0.51, p = 0.001), and positively with TMB (r = 0.50, p = 0.003). S100β levels were associated with DVR (r = -0.51, p = 0.002), TMB (r = 0.46, p = 0.008), Stroop Color-Word (r = -0.67, p < 0.0001), and N-Back Total (r = -0.52, p = 0.003). RA is associated with impaired cognitive performance associated with higher levels of CNS-related autoantibodies and S100β levels. Given the importance of myelin integrity to cognition, our data indicate that these autoantibodies may be harmful to proper cognitive function.

Rheumatoid arthritis: Recent advances on its etiology, role of cytokines and pharmacotherapy

An autoimmune disease is defined as a clinical syndrome resulted from an instigation of both T cell and B cell or individually, in the absence of any present infection or any sort of distinguishable cause. Clonal deletion of auto reactive cells remains the central canon of immunology for decades, keeping the role of T cell and B cell aside, which are actually the guards to recognize the entry of foreign body. According to NIH, 23.5 million Americans are all together affected by these diseases. They are rare, but with the exception of RA. Rheumatoid arthritis is chronic and systemic autoimmune response to the multiple joints with unknown ethology, progressive disability, systemic complications, early death and high socioeconomic costs. Its ancient disease with an old history found in North American tribes since 1500 BCE, but its etiology is yet to be explored. Current conventional and biological therapies used for RA are not fulfilling the need of the patients but give only partial responses. There is a lack of consistent and liable biomarkers of prognosis therapeutic response, and toxicity. Rheumatoid arthritis is characterized by hyperplasic synovium, production of cytokines, chemokines, autoantibodies like rheumatoid factor (RF) and anticitrullinated protein antibody (ACPA), osteoclastogensis, angiogenesis and systemic consequences like cardiovascular, pulmonary, psychological, and skeletal disorders. Cytokines, a diverse group of polypeptides, play critical role in the pathogenesis of RA. Their involvement in autoimmune diseases is a rapidly growing area of biological and clinical research. Among the proinflammatory cytokines, IL-1α/β and TNF-α trigger the intracellular molecular signalling pathway responsible for the pathogenesis of RA that leads to the activation of mesenchymal cell, recruitment of innate and adaptive immune system cells, activation of synoviocytes which in term activates various mediators including tumour necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), interleukin-6 (IL-6) and interleukin-8 (IL-8), resulting in inflamed synovium, increase angiogenesis and decrease lymphangiogensis. Their current pharmacotherapy should focus on their three phases of progression i.e. prearthritis phase, transition phase and clinical phase. In this way we will be able to find a way to keep the balance between the pro and anti-inflammatory cytokines that is believe to be the dogma of pathogenesis of RA. For this we need to explore new agents, whether from synthetic or natural source to find the answers for unresolved etiology of autoimmune diseases and to provide a quality of life to the patients suffering from these diseases specifically RA.

Evolution, immunity and the emergence of brain superautoantigens

While some autoimmune disorders remain extremely rare, others largely predominate the epidemiology of human autoimmunity. Notably, these include psoriasis, diabetes, vitiligo, thyroiditis, rheumatoid arthritis and multiple sclerosis. Thus, despite the quasi-infinite number of "self" antigens that could theoretically trigger autoimmune responses, only a limited set of antigens, referred here as superautoantigens, induce pathogenic adaptive responses. Several lines of evidence reviewed in this paper indicate that, irrespective of the targeted organ (e.g. thyroid, pancreas, joints, brain or skin), a significant proportion of superautoantigens are highly expressed in the synaptic compartment of the central nervous system (CNS). Such an observation applies notably for GAD65, AchR, ribonucleoproteins, heat shock proteins, collagen IV, laminin, tyrosine hydroxylase and the acetylcholinesterase domain of thyroglobulin. It is also argued that cognitive alterations have been described in a number of autoimmune disorders, including psoriasis, rheumatoid arthritis, lupus, Crohn's disease and autoimmune thyroiditis. Finally, the present paper points out that a great majority of the "incidental" autoimmune conditions notably triggered by neoplasms, vaccinations or microbial infections are targeting the synaptic or myelin compartments. On this basis, the concept of an immunological homunculus, proposed by Irun Cohen more than 25 years ago, is extended here in a model where physiological autoimmunity against brain superautoantigens confers both: i) a crucial evolutionary-determined advantage via cognition-promoting autoimmunity; and ii) a major evolutionary-determined vulnerability, leading to the emergence of autoimmune disorders in Homo sapiens. Moreover, in this theoretical framework, the so called co-development/co-evolution model, both the development (at the scale of an individual) and evolution (at the scale of species) of the antibody and T-cell repertoires are coupled to those of the neural repertoires (i.e. the distinct neuronal populations and synaptic circuits supporting cognitive and sensorimotor functions). Clinical implications and future experimental insights are also presented and discussed.

Cerebral magnetic resonance imaging in quiescent Crohn’s disease patients with fatigue

AIM

To evaluate brain involvement in quiescent Crohn’s disease (CD) patients with fatigue using quantitative magnetic resonance imaging (MRI).

METHODS

Multiple MRI techniques were used to assess cerebral changes in 20 quiescent CD patients with fatigue (defined with at least 6 points out of an 11-point numeric rating scale compared with 17 healthy age and gender matched controls without fatigue. Furthermore, mental status was assessed by cognitive functioning, based on the neuropsychological inventory including the different domains global cognitive functioning, memory and executive functioning and in addition mood and quality of life scores. Cognitive functioning and mood status were correlated with MRI findings in the both study groups.

RESULTS

Reduced glutamate + glutamine (Glx = Glu + Gln) concentrations (P = 0.02) and ratios to total creatine (P = 0.02) were found in CD patients compared with controls. Significant increased Cerebral Blood Flow (P = 0.05) was found in CD patients (53.08 ± 6.14 mL/100 g/min) compared with controls (47.60 ± 8.62 mL/100 g/min). CD patients encountered significantly more depressive symptoms (P < 0.001). Cognitive functioning scores related to memory (P = 0.007) and executive functioning (P = 0.02) were lower in CD patients and both scores showed correlation with depression and anxiety. No correlation was found subcortical volumes between CD patients and controls in the T₁-weighted analysis. In addition, no correlation was found between mental status and MRI findings.

CONCLUSION

This work shows evidence for perfusion, neurochemical and mental differences in the brain of CD patients with fatigue compared with healthy controls.

Cognitive dysfunction correlates with elevated serum S100B concentration in drug-free acutely relapsed patients with schizophrenia

S100B, a biomarker of glial dysfunction and blood-brain barrier (BBB) disruption, has been proposed to be involved in the pathophysiology of schizophrenia. In the present study, we aimed at exploring the association of serum S100B levels with cognitive deficits using MATRICS Consensus Cognitive Battery (MCCB) in schizophrenia, by excluding the impact of antipsychotics. Sixty-two unmedicated patients with schizophrenia during their acute phases were divided into a drug-naïve group (n=34) and a drug-free group (n=28). S100B serum concentrations were measured and MCCB was administered to all of the patients. Forty healthy controls donated their blood samples for S100B assessment. The results indicated that serum S100B was significantly elevated in the drug-naive/free acute-stage schizophrenic patients when compared to the healthy controls. In the drug-free group, the serum S100B level was an independent contributor to the global cognitive dysfunctions, particularly for the speed of processing, attention/vigilance, visual learning and reasoning/problem solving subscores. Nevertheless, no significant associations between S100B and MCCB composite score or any cognitive domain subscore were observed in the drug-naïve group. These findings support the hypothesis that glial dysfunction and associated marker protein S100B may contribute to the pathophysiologic development of neurocognitive deficits in the relapsed individuals with schizophrenia.

Variant of multiple sclerosis with dementia and tumefactive demyelinating brain lesions

We describe an unusual clinical and diagnostic feature of a patient with multiple sclerosis (MS). A 25-year-old woman was admitted to the Neurology department (December 2009) with one month history of rapid cognitive deterioration. She had poor cognition, dysphasia, reduction in visual acuity and temporal pallor of the optic discs. She had prolonged latencies of P100 component of visual evoked potentials (VEPs). Magnetic resonance imaging (MRI)-brain showed multifocal large (≥ 3 cm) white-matter hypointense lesions in T1W and hyperintense in T2W and fluid-attenuated inversion recovery images and patchy enhancement. A diagnosis of tumefactive MS was given. She received two consecutive 5-d courses of 1 g daily intravenous methylprednisolone for 2 mo and oral prednisolone in dose of 80 mg twice/daily in between. At the 3^rd month, Mini Mental State Examination and VEPs returned to normal but not the MRI. Patient continued oral steroids after hospital discharge (March 2010) for 9 mo with significant MRI improvement after which tapering of steroids started for a year. The patient refused immunomodulation therapy due to her low socioeconomic status. Neither clinical relapse nor new MRI lesions were observed throughout the next 4 years. In spite of the aggressive course of tumefactive MS variant, good prognosis may be seen in some patients.

A review of the neuro- and systemic inflammatory responses in post concussion symptoms: Introduction of the "post-inflammatory brain syndrome" PIBS

Post-concussion syndrome is an aggregate of symptoms that commonly present together after head injury. These symptoms, depending on definition, include headaches, dizziness, neuropsychiatric symptoms, and cognitive impairment. However, these symptoms are common, occurring frequently in non-head injured controls, leading some to question the existence of post-concussion syndrome as a unique syndrome. Therefore, some have attempted to explain post-concussion symptoms as post-traumatic stress disorder, as they share many similar symptoms and post-traumatic stress disorder does not require head injury. This explanation falls short as patients with post-concussion syndrome do not necessarily experience many key symptoms of post-traumatic stress disorder. Therefore, other explanations must be sought to explain the prevalence of post-concussion like symptoms in non-head injury patients. Many of the situations in which post-concussion syndrome like symptoms may be experienced such as infection and post-surgery are associated with systemic inflammatory responses, and even neuroinflammation. Post-concussion syndrome itself has a significant neuroinflammatory component. In this review we examine the evidence of neuroinflammation in post-concussion syndrome and the potential role systemic inflammation plays in post-concussion syndrome like symptoms. We conclude that given the overlap between these conditions and the role of inflammation in their etiologies, a new term, post-inflammatory brain syndromes (PIBS), is necessary to describe the common outcomes of many different inflammatory insults. The concept of post-concussion syndrome is in its evolution therefore, the new term post-inflammatory brain syndromes provides a better understanding of etiology of its wide-array of symptoms and the wide array of conditions they can be seen in.

New insights into the impact of neuro-inflammation in rheumatoid arthritis

Rheumatoid arthritis (RA) is considered to be, in many respects, an archetypal autoimmune disease that causes activation of pro-inflammatory pathways resulting in joint and systemic inflammation. RA remains a major clinical problem with the development of several new therapies targeted at cytokine inhibition in recent years. In RA, biologic therapies targeted at inhibition of tumor necrosis factor alpha (TNFα) have been shown to reduce joint inflammation, limit erosive change, reduce disability and improve quality of life. The cytokine TNFα has a central role in systemic RA inflammation and has also been shown to have pro-inflammatory effects in the brain. Emerging data suggests there is an important bidirectional communication between the brain and immune system in inflammatory conditions like RA. Recent work has shown how TNF inhibitor therapy in people with RA is protective for Alzheimer's disease. Functional MRI studies to measure brain activation in people with RA to stimulus by finger joint compression, have also shown that those who responded to TNF inhibition showed a significantly greater activation volume in thalamic, limbic, and associative areas of the brain than non-responders. Infections are the main risk of therapies with biologic drugs and infections have been shown to be related to disease flares in RA. Recent basic science data has also emerged suggesting that bacterial components including lipopolysaccharide induce pain by directly activating sensory neurons that modulate inflammation, a previously unsuspected role for the nervous system in host-pathogen interactions. In this review, we discuss the current evidence for neuro-inflammation as an important factor that impacts on disease persistence and pain in RA.

Burden of disease in treated rheumatoid arthritis patients: going beyond the joint

OBJECTIVE

The disease burden in rheumatoid arthritis (RA) extends beyond the joint. This article evaluates the physical and psychosocial extra-articular burden of treated RA and relationships among diverse disease manifestations.

METHODS

MEDLINE searches identified papers published in English from January 2003 to December 2012 that evaluated systemic complications and psychosocial aspects associated with RA. Preference was given to studies with randomized cohorts and large (>100) sample sizes. Of 378 articles identified in the initial search, 118 were selected for inclusion.

RESULTS

RA is associated with multiple comorbidities and psychosocial impairments, including cardiovascular disease, osteoporosis, interstitial lung disease, infection, malignancies, fatigue, depression, cognitive dysfunction, reduced work performance, work disability, and decreased health-related quality of life. The etiology of the extra-articular burden may reflect the systemic inflammation and immune system alteration associated with RA, metabolic imbalances and side effects related to treatment, or the influence of comorbidities. Strategies that may help to reduce the extra-articular disease burden include personalized medicine and the potential introduction of treatments with new mechanisms of action.

CONCLUSION

Despite improvements in treating joint disease, the extra-articular burden in RA remains substantial, encompassing multiple comorbidities and psychosocial impairments.

CD166/ALCAM mediates proinflammatory effects of S100B in delayed type hypersensitivity

Promiscuity of pattern recognition receptors, such as receptor for advanced glycation end products (RAGE), allows for a complex regulatory network controlling inflammation. Scavenging of RAGE ligands by soluble RAGE treatment is effective in reducing delayed-type hypersensitivity (DTH), even in RAGE(-/-) mice by 50% (p < 0.001). This has led to the hypothesis that molecules scavenged by soluble RAGE bind to receptors other than RAGE. This study identifies CD166/ALCAM (ALCAM) as a close structural and functional homolog of RAGE, and it shows that binding of S100B to CD166/ALCAM induces dose- and time-dependent expression of members of the NF-κB family in wild type (WT) and RAGE(-/-) mouse endothelial cells. Blocking CD166/ALCAM expression using small interfering RNA completely inhibited S100B-induced NF-κB activation in RAGE(-/-), but not in WT cells. The in vivo significance of these observations was demonstrated by attenuation of DTH in WT and RAGE(-/-) animals pretreated with CD166/ALCAM small interfering RNA by 50% and 40%, respectively (p < 0.001). Experiments in ALCAM(-/-) animals displayed an only slight reduction of 16% in DTH, explained by compensatory reciprocal upregulation of RAGE in animals devoid of CD166/ALCAM, and vice versa. Consistently, ALCAM(-/-) mice, but not WT mice treated with RAGE small interfering RNA show a 35% reduction in DTH, and ALCAM(-/-) RAGE(-/-) double-knockout mice show a 27% reduction in DTH reaction. Thus, S100B is a proinflammatory cytokine bridging RAGE and CD166/ALCAM downstream effector mechanisms, both being compensatory upregulated after genetic deletion of its counterpart.