Pre-symptomatic autoimmunity in rheumatoid arthritis: when does the disease start?

Immune cell-specific and common molecular signatures in rheumatoid arthritis through molecular network approaches

Rheumatoid arthritis (RA) is an autoimmune disorder and common symptom of RA is chronic synovial inflammation. The pathogenesis of RA is not fully understood. Therefore, we aimed to identify underlying common and distinct molecular signatures and pathways among ten types of tissue and cells obtained from patients with RA. In this study, transcriptomic data including synovial tissues, macrophages, blood, T cells, CD4+T cells, CD8+T cells, natural killer T (NKT), cells natural killer (NK) cells, neutrophils, and monocyte cells were analyzed with an integrative and comparative network biology perspective. Each dataset yielded a list of differentially expressed genes as well as a reconstruction of the tissue-specific protein-protein interaction (PPI) network. Molecular signatures were identified by a statistical test using the hypergeometric probability density function by employing the interactions of transcriptional regulators and PPI. Reporter metabolites of each dataset were determined by using genome-scale metabolic networks. It was defined as the common hub proteins, novel molecular signatures, and metabolites in two or more tissue types while immune cell-specific molecular signatures were identified, too. Importantly, miR-155-5p is found as a common miRNA in all tissues. Moreover, NCOA3, PRKDC and miR-3160 might be novel molecular signatures for RA. Our results establish a novel approach for identifying immune cell-specific molecular signatures of RA and provide insights into the role of common tissue-specific genes, miRNAs, TFs, receptors, and reporter metabolites. Experimental research should be used to validate the corresponding genes, miRNAs, and metabolites.

Profiling of differentially expressed circRNAs and functional prediction in peripheral blood mononuclear cells from patients with rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a chronic autoimmune disease associated with an increased risk of death, but its underlying mechanisms are not fully understood. Circular RNAs (circRNAs) have recently been implicated in various biological processes. The aim of this study was to investigate the key circRNAs related to RA.

METHODS

A microarray assay was used to identify the differentially expressed circRNAs (DEcircRNAs) in peripheral blood mononuclear cells (PBMCs) from patients with RA compared to patients with osteoarthritis (OA) and healthy controls. Then, quantitative real-time PCR was applied to verify the DEcircRNAs, and correlations between the levels of DEcircRNAs and laboratory indices were analysed. We also performed extensive bioinformatic analyses including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genome (KEGG) pathway and potential circRNA-miRNA-mRNA network analyses to predict the function of these DEcircRNAs.

RESULTS

A total of 35,342 and 6146 DEcircRNAs were detected in RA patients compared to controls and OA patients, respectively. Nine out of the DEcircRNAs in RA were validated by real-time PCR. There were correlations between the levels of DEcircRNAs and some of the laboratory indices. GO analyses revealed that these DEcircRNAs in RA were closely related to cellular protein metabolic processes, gene expression, the immune system, cell cycle, posttranslational protein modification and collagen formation. Functional annotation of host genes of these DEcircRNAs was implicated in several significantly enriched pathways, including metabolic pathways, ECM-receptor interaction, the PI3K-Akt signalling pathway, the AMPK signalling pathway, leukocyte transendothelial migration, platelet activation and the cAMP signalling pathway, which might be responsible for the pathophysiology of RA.

CONCLUSIONS

The findings of this study may help to elucidate the role of circRNAs in the specific mechanism underlying RA.Key messagesMicroarray assays showed that a total of 35,342 and 6146 DEcircRNAs were detected in RA patients compared to controls and OA patients, respectively.Nine out of the DEcircRNAs in RA were validated by real-time PCR, and the levels of the DEcircRNAs were related to some of the laboratory indices.GO analyses revealed that the DEcircRNAs in RA were closely related to cellular protein metabolic processes, gene expression, the immune system, etc.Functional annotation of host genes of the DEcircRNAs in RA was implicated in several significantly enriched pathways, including metabolic pathways, ECM-receptor interaction, the PI3K-Akt signalling pathway, etc.

Immune checkpoints in rheumatoid arthritis: progress and promise

Rheumatoid arthritis (RA) is one of the most prevalent autoimmune inflammatory conditions, and while the mechanisms driving pathogenesis are yet to be completely elucidated, self-reactive T cells and immune checkpoint pathways have a clear role. In this review, we provide an overview of the importance of checkpoint pathways in the T cell response and describe the involvement of these in RA development and progression. We discuss the relationship between immune checkpoint therapy in cancer and autoimmune adverse events, draw parallels with the involvement of immune checkpoints in RA pathobiology, summarise emerging research into some of the lesser-known pathways, and the potential of targeting checkpoint-related pathways in future treatment approaches to RA management.

Association of Antibodies to Prevotella copri in Anti-Cyclic Citrullinated Peptide-Positive Individuals At Risk of Developing Rheumatoid Arthritis and in Patients With Early or Established Rheumatoid Arthritis

OBJECTIVE

Prevotella copri (P copri), a gut commensal, has been reported to be an immune-relevant organism in individuals with rheumatoid arthritis (RA). This study sought to evaluate anti-P copri (anti-Pc) antibody responses in our participant cohorts and to determine when in the natural history of RA such responses develop.

METHODS

We analyzed serum levels of immunoglobulin A (IgA) and IgG antibodies from a 27-kd protein of P copri (anti-Pc-p27), an immunogenic P copri protein, in study participants at risk of developing RA, participants who transitioned to RA, participants with early RA (<1 year of disease), and participants with established RA, with comparisons made to their matched controls. We also evaluated anti-Pc-p27 antibody levels in individuals stratified by RA-related autoantibody status.

RESULTS

Overall, participants with RA had significantly higher IgA anti-Pc-p27 antibody levels and trended toward higher IgG anti-Pc-p27 antibody levels compared with matched controls. When stratified by early versus established RA, participants with early RA had median IgG anti-Pc-p27 antibody levels that were overall higher, whereas median IgA anti-Pc-p27 antibody levels were statistically significantly higher in participants with established RA compared with their matched controls. In the autoantibody-specific analyses, the at-risk population with anti-cyclic citrullinated peptide (anti-CCP) antibodies, but not rheumatoid factor (RF), trended toward increased levels of IgG anti-Pc-p27. Additionally, RA participants who were seropositive for both CCP and RF had significantly increased levels of IgA anti-Pc-p27 antibodies and trended toward higher levels of IgG anti-Pc-p27 antibodies compared with matched controls.

CONCLUSION

Our findings support a potential etiologic role for P copri in both RA preclinical evolution and the subsequent pathogenesis of synovitis.

Preferences for preventive treatments for rheumatoid arthritis: discrete choice survey in the UK, Germany and Romania

OBJECTIVE

To quantify preferences for preventive therapies for rheumatoid arthritis (RA) across three countries.

METHODS

A web-based survey including a discrete choice experiment was administered to adults recruited via survey panels in the UK, Germany and Romania. Participants were asked to assume they were experiencing arthralgia and had a 60% chance of developing RA in the next 2 years and completed 15 choices between no treatment and two hypothetical preventive treatments. Treatments were defined by six attributes (effectiveness, risks and frequency/route of administration) with varying levels. Participants also completed a choice task with fixed profiles reflecting subjective estimates of candidate preventive treatments. Latent class models (LCMs) were conducted and the relative importance of attributes, benefit-risk trade-offs and predicted treatment uptake was subsequently calculated.

RESULTS

Completed surveys from 2959 participants were included in the analysis. Most participants preferred treatment over no treatment and valued treatment effectiveness to reduce risk more than other attributes. A five-class LCM best fitted the data. Country, perceived risk of RA, health literacy and numeracy predicted class membership probability. Overall, the maximum acceptable risk for a 40% reduction in the chance of getting RA (60% to 20%) was 21.7%, 19.1% and 2.2% for mild side effects, serious infection and serious side effects, respectively. Predicted uptake of profiles reflecting candidate prevention therapies differed across classes.

CONCLUSION

Effective preventive pharmacological treatments for RA were acceptable to most participants. The relative importance of treatment attributes and likely uptake of fixed treatment profiles were predicted by participant characteristics.

From vaccines to nanovaccines: A promising strategy to revolutionize rheumatoid arthritis treatment

Rheumatoid arthritis (RA) is a joint-related autoimmune disease that is difficult to cure. Most therapeutics act to alleviate the symptoms but not correct the causes of RA. Novel strategies that specifically target the causes are highly needed for RA management. Currently, early interruption of RA is increasingly suggested but the corresponding therapeutics are not available. Vaccines that have shown great success to combat infection, cancer, degenerative diseases, autoimmune diseases, etc. are ideal candidates for a new generation of anti-RA therapeutics to correct the causes and prevent RA or interrupt RA in early phases. Anti-RA vaccines can be divided into two major categories. One is to induce neutralizing antibodies and the other is to induce antigen-specific immune tolerance. The vaccines are inherently linked to nanotechnology because they usually need a biomacromolecule or carrier to provoke sufficient immune responses. In the past decade, designed nanocarriers such as nanoparticles, liposomes, nanoemulsion, etc., have been applied to optimize the vaccines for autoimmune disease treatment. Nanotechnology endows vaccines with a higher biostability, tunable in vivo behavior, better targeting, co-delivery with stimulatory agents, regulatory effects on immune responses, etc. In this review, unmet medical needs for RA treatment and anti-RA vaccinology are first introduced. The development of anti-RA therapies from vaccines to nanovaccines are then reviewed and perspectives on how nanotechnology promotes vaccine development and advancement are finally provided. In addition, challenges for anti-RA vaccine development are summarized and advantages of nanovaccines are analyzed. In conclusion, nanovaccines will be a promising strategy to revolutionize the treatment of RA by correcting the causes in an early phase of RA.

Microbiota-assisted therapy for systemic inflammatory arthritis: advances and mechanistic insights

Research on the influence of gut microbiota on systemic inflammatory arthritis has exploded in the past decade. Gut microbiota changes may be a crucial regulatory component in systemic inflammatory arthritis. As a result of advancements in the field, microbiota-assisted therapy has evolved, but this discipline is still in its infancy. Consequently, we review the limitations of current systemic inflammatory arthritis treatment, analyze the connection between the microbiota and arthritis, and summarize the research progress of microbiota regulating systemic inflammatory arthritis and the further development aspects of microbiota-assisted therapy. Finally, the partial mechanisms of microbiota-assisted therapy of systemic inflammatory arthritis are being discussed. In general, this review summarizes the current progress, challenges, and prospects of microbiota-assisted therapy for systemic inflammatory arthritis and points out the direction for the development of microbiota-assisted therapy in the future.

Increased frequency of TIGIT+ CD4 T Cell subset in autoantibody-positive first-degree relatives of patients with rheumatoid arthritis

Background

Despite immune cell dysregulation being an important event preceding the onset of rheumatoid arthritis (RA), the phenotype of T and B cells in preclinical RA is less understood. The aim of this study was to characterize T and B cell populations in RA patients and their autoantibody (aAb) negative and positive first-degree relatives (FDR).

Methods

Cryopreserved peripheral blood mononuclear cells (PBMCs) collected at scheduled visits from aAb-(n=25), and aAb+ FDR (n=10) and RA patients (n=13) were thawed and stained using optimized antibody cocktails as per a specific 13-color T or B cell panel. Immunophenotyping was performed using a Cytoflex LX (Beckman-Coulter) flow cytometer and FlowJo software was used for analyzing the frequency of immune cell populations.

Results

Multicolor flow cytometry experiments identified an increased TIGIT expression in circulating lymphocytes of aAb+ FDR and RA patients, relative to aAb- FDR (P<0.01). These TIGIT⁺ T cells exhibited a memory phenotype and expressed high levels of PD-1, ICOS, HLA-DR, CXCR3 and CXCR5. Moreover, increased TIGIT⁺ CD4 T cell frequency correlated with the frequency of PD-1⁺ CD4 T cells (r = 0.4705: P = 0.0043) and circulating levels of ACPA and RF. We also identified a decreased frequency of CD27+IgD- switched memory B cells in RA patients (P < 0.01), while increased frequency of TIGIT+ CD4 T cells in FDR correlated with the frequency of PD1⁺PTEN⁺ B cells (r = 0.6838, P = 0.0004) and autoantibody positivity (P = 0.01).

Conclusion

We demonstrate TIGIT as a distinct CD4 T cell marker for differentiating aAb- FDR from aAb+FDR and might play a critical role in regulating T and B cell crosstalk in preclinical RA.

MicroRNA-122-3p plays as the target of long non-coding RNA LINC00665 in repressing the progress of arthritis

MicroRNAs (miRNAs) play important roles in many diseases, including rheumatoid arthritis (RA). However, the mechanisms underlying the effects of miR-122-3p-3p on RA are not distinct and require further investigation. Patients with RA and healthy controls were recruited to analyze the miR-122-3p levels. The MH7A cells were stimulated with interleukin (IL)-1β to mimic the local inflammation of RA. Cell Counting Kit-8 (CCK-8) and flow cytometry were performed to measure the viability and apoptosis of MH7A cells. Diana tools and TargetScan were used to predict the target relationships. Luciferase reporter assay was used to validate the target relationship. miR-122-3p is downregulated in RA patients and IL-1β-stimulated MH7A cells. miR-122-3p suppresses MH7A cell viability and promotes MH7A cell apoptosis. miR-122-3p targets LINC00665. LINC00665 eliminates the inhibitory effect of miR-122-3p on IL-1β-stimulated MH7A cells. Eukaryotic translation initiation factor 2 alpha kinase 1 (EIF2AK1) targets miR-122-3p. In addition, EIF2AK1 is highly expressed in patients with RA. In addition, EIF2AK1 activates the mTOR signaling pathway. miR-122-3p represses RA progression by reducing cell viability and increasing synoviocyte apoptosis.

Association Study of Anticitrullinated Peptide Antibody Status with Clinical Manifestations and SNPs in Patients Affected with Rheumatoid Arthritis: A Pilot Study

Introduction. Rheumatoid arthritis (RA) is an autoimmune disease of unknown etiology that leads to disability due to articular and extra-articular damage. RA prevalence is variable. The disease is most common among females with a 3 : 1 ratio. The interaction of environmental and host factors contributes to RA development. Currently, the genome-wide association studies (GWAS) give the opportunity to uncover the RA genetic background. Anticitrullinated peptide antibody (ACPA) is a highly specific RA antibody, associated with poor prognosis and severe course of RA, and regulated by numerous genes. Our study is aimed at investigating whether there are any clinical and genetic aspects correlate with ACPA presence in Kazakhstani patients with RA. Indeed, the available studies on this subject are focused on Caucasian and East Asian populations (mainly Japanese and Chinese), and there are scarce data from Central Asia. Methods. Our study included 70 RA patients. Patients’ blood samples were collected and genotyped for 14 SNPs by real-time polymerase chain reaction (RT-PCR). General examination, anamnestic, and clinical and laboratory data collection were carried out. Statistical analysis was performed using R statistics. Results and Conclusion. Our study revealed a significant association of ACPA positivity with Fc receptor-like 3 (FCRL3) and ACPA negativity with signal transducer and activator of transcription 4 (STAT4) genes, but not with T cell activation Rho GTPase activating protein (TAGAP). In addition, ACPA positivity was associated with radiographic progression, rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), age of RA onset, the patient global assessment, body mass index (BMI), and Gamma globulin. Conclusion. Remained 11 earlier identified significantly associated in Caucasian and Asian population SNPs were not replicated in our cohort. Further studies on larger cohorts are needed to confirm our findings with higher confidence levels and stronger statistical power.

Rheumatoid Arthritis: Early Diagnosis and Treatment

Rheumatoid arthritis (RA) is a chronic, progressive inflammatory disorder that manifests as a symmetric polyarthritis of small and large joints that may lead to joint and periarticular structural damage and the consequences of systemic inflammation. This overview of early RA examines the unmet needs and challenges in RA, how to best diagnose RA, and pitfalls in early diagnosis and treatment. The rules for referral to a rheumatologist are reviewed. Primary care physicians are at the front line of early diagnosis and need to start disease-modifying therapy as soon as a diagnosis of RA is established.

Perspectives of at-Risk Individuals on Preventive Intervention for Rheumatoid Arthritis: A Mini Review

There has been intense research focus on the biological mechanisms underlying the transition from health to disease for rheumatoid arthritis (RA) over recent years, and it is now well established that a state of autoimmunity precedes the development of symptoms for a large proportion of patients. This has led to an increased interest in the identification of at-risk groups and the potential for preventive intervention. The ability of several immunomodulatory agents to delay or prevent RA is under investigation and novel cellular therapies are in development. Preventive approaches are also being assessed in other chronic autoimmune diseases. For example, an anti-CD3 antibody has recently been shown to delay progression to type 1 diabetes in non-diabetic relatives of patients identified as being at high risk. The identification and treatment of individuals as being at risk of a disease where there is a degree of uncertainty around the potential for benefit is socially and ethically challenging. Recently reported difficulties in recruitment to RA prevention trials have underlined the importance of understanding the perspectives of at-risk individuals to identify barriers and facilitators that need to be addressed in order for preventive strategies to be acceptable. Understanding of their preferences for benefits and risks of preventive interventions can inform efficient intervention prioritization, prevention trial design and the development of informational resources for those at risk. In this review we summarize current knowledge of preferences for RA prevention and make recommendations for further research needed to ensure efficient development of preventive therapies and clinical implementation.

Association Between Rheumatoid Arthritis and Serum Vitamin D Levels

Introduction

Vitamin D is responsible for regulating innate and adaptive immune responses and for boosting the immune system; hence, a decline in its levels results in autoimmunity. Current studies have linked the deficiency of vitamin D to different autoimmune diseases, including rheumatoid arthritis (RA). In this study, we will determine the association between vitamin D level and RA.

Methods

This is a case-control study, conducted in a tertiary care hospital in Pakistan from January 2021 to May 2021. Three hundred patients with a confirmed recent diagnosis of RA were enrolled as the study group. Another 300 participants without RA, matched for age and gender, were enrolled in the study as a control group. RA was diagnosed on the basis of clinical symptoms, radiological features on X-ray, and anti-citrullinated protein levels of more than 20 u/mL.

Results

The mean vitamin D level in participants with RA was significantly lower than in the placebo group (30.18 ± 6.27 vs. 38.29 ± 7.98; p-value: <0.0001). The mean vitamin D level in participants with positive RF patients was significantly lower compared to rheumatoid factor (RF)-negative RA patients (29.21 ± 5.16 vs. 32.26 ± 7.02; p-value: <0.0001). There were more participants with hypovitaminosis D in RF-positive participants as compared to RF negative (88.6% vs. 44.3%; p-value: 0.00001).

Conclusion

There is a high prevalence of vitamin D deficiency in patients with RA and there is a link with disease severity. Therefore, a high index of suspicion is required while evaluating the at-risk patients, especially women, with complaints of vitamin D deficiency. Vitamin D supplementation may be needed for the prevention or avoidance of the progression of the disease.

Identification of potential autoantigens in anti-CCP-positive and anti-CCP-negative rheumatoid arthritis using citrulline-specific protein arrays

The presence or absence of autoantibodies against citrullinated proteins (ACPAs) distinguishes two main groups of rheumatoid arthritis (RA) patients with different etiologies, prognoses, disease severities, and, presumably, disease pathogenesis. The heterogeneous responses of RA patients to various biologics, even among ACPA-positive patients, emphasize the need for further stratification of the patients. We used high-density protein array technology for fingerprinting of ACPA reactivity. Identification of the proteome recognized by ACPAs may be a step to stratify RA patients according to immune reactivity. Pooled plasma samples from 10 anti-CCP-negative and 15 anti-CCP-positive RA patients were assessed for ACPA content using a modified protein microarray containing 1631 different natively folded proteins citrullinated in situ by protein arginine deiminases (PADs) 2 and PAD4. IgG antibodies from anti-CCP-positive RA plasma showed high-intensity binding to 87 proteins citrullinated by PAD2 and 99 proteins citrullinated by PAD4 without binding significantly to the corresponding native proteins. Curiously, the binding of IgG antibodies in anti-CCP-negative plasma was also enhanced by PAD2- and PAD4-mediated citrullination of 29 and 26 proteins, respectively. For only four proteins, significantly more ACPA binding occurred after citrullination with PAD2 compared to citrullination with PAD4, while the opposite was true for one protein. We demonstrate that PAD2 and PAD4 are equally efficient in generating citrullinated autoantigens recognized by ACPAs. Patterns of proteins recognized by ACPAs may serve as a future diagnostic tool for further subtyping of RA patients.

Detection of circulating highly expanded T-cell clones in at-risk individuals for rheumatoid arthritis before the clinical onset of the disease

OBJECTIVES

To quantitatively profile the T-cell repertoire in the peripheral blood of individuals genetically at risk for RA, namely first-degree relatives of RA patients (RA-FDR) at different phases of disease development.

METHODS

Next-generation sequencing of the TCR CDR3β repertoire was performed on genomic DNA isolated from whole blood samples of RA-FDR selected at three different pre-clinical stages and of matched RA patients (n = 20/group). T-cell clones were identified by their unique sequence and their degree of expansion (frequency) within each sample was characterized. Clones with a frequency over 0.5% were considered highly expanded clones (HEC).

RESULTS

The absolute number of HEC was significantly higher in established RA patients (mean 4.65) and tended to be higher in symptomatic RA-FDR (mean 3.4) compared with asymptomatic RA-FDR (mean 1.55, P =0.003 and P =0.07, respectively). Asymptomatic individuals with high levels of ACPA did not differ from asymptomatic RA-FDR in terms of absolute number and frequency of clones. The number of HEC tended to be slightly higher at the time of RA onset (P =0.055). Neither clones shared by several patients, nor clones previously associated with RA, were preferentially present within or between the different groups. Finally, a longitudinal analysis did not allow to uncover a kinetic expansion of RA-specific clones closely correlated with disease development.

CONCLUSIONS

HEC were detected in the peripheral blood before the clinical onset of RA, in particular in the later pre-clinical phase of RA development, and their presence increased over time.

Deciphering Role of Cytokines for Therapeutic Strategies Against Rheumatoid Arthritis

Rheumatoid Arthritis (RA) is a systemic, chronic, autoimmune, inflammatory disorder that affects both large and small synovial joints in a symmetric pattern. RA initiates as painful inflammation of the joints leading to stiffness of joint, joint destruction and further worsens the condition causing permanent irreversible damage to the joints, making them physically disabled. Across the globe, there are around 1.2 million cases of RA reported. Inspite of various available therapeutic and pharmacological agents against RA, none of the treatments assure complete cure. Understanding the in depth-role of cytokines and interleukins in the disease pathogenesis of RA could help in exploiting them for developing novel therapeutic strategies against RA. This review provides insights into the pathogenesis of RA and gives a brief overview of cytokines, which play an important role in the progression of the disease. We have also discussed the possible role of interleukins in the context of RA, which could help future researchers to explore them for identifying new therapeutic agents.

The impact of autoantibodies against citrullinated, carbamylated, and acetylated peptides on radiographic progression in patients with new-onset rheumatoid arthritis: an observational cohort study

BACKGROUND

A range of anti-modified protein antibodies (AMPAs) are associated with rheumatoid arthritis. We aimed to assess the relationship between AMPA profiles and radiographic progression in patients with new-onset rheumatoid arthritis.

METHODS

In this cohort study, we obtained samples and data from the Scottish Early Rheumatoid Arthritis (SERA) inception cohort and biobank, which recruited patients with new-onset rheumatoid arthritis or undifferentiated arthritis who had at least one swollen joint from 20 hospitals across Scotland. AMPAs in plasma samples were measured by ELISAs at baseline. Paired radiographs of the hands and feet were taken at baseline and at 1 year and were scored with the Sharp-van der Heijde (SvH) method. We calculated differences in radiographic progression using estimated marginal mean changes between baseline and 1 year, with the baseline values of radiographic variables, rheumatoid factor, sex, age at recruitment, symptom duration, and Disease Activity Score 28 with C-reactive protein included as covariates.

FINDINGS

Between March 1, 2011, and April, 30, 2015, 1073 patients were recruited to the SERA study. 362 patients with rheumatoid arthritis were included in our study and had their AMPA profiles determined. Patients were grouped into four main autoantibody profiles by reactivities to post-translational modifications: single positivity for anti-citrullinated peptide antibodies (ACPAs; 73 [20%]); double positivity for ACPAs and anti-acetylated peptide antibodies (AAPAs; 45 [12%]); triple positivity for ACPAs, AAPAs, and anti-carbamylated peptide antibodies (151 [42%]); and AMPA negativity (74 [20%]). 19 (5%) patients were in one of the minor autoantibody groups. Of the 233 patients with both antibody data and radiographs of sufficient quality, triple-positive patients had more radiographic progression between baseline and 12 months (estimated mean change in total SvH score 1·8, 95% CI 0·9-2·6, SE 0·4) than did single-positive patients (0·5, 0·1-1·0, 0·2; estimated mean difference in the total change in SvH score 1·2, 95% CI 0·1-2·4, SE 0·5). There was no difference in radiographic progression between single positive patients and AMPA negative patients (estimated mean change in total SvH score 0·7, 95% CI 0·1-1·4, SE 0·3; estimated mean difference in the total change in SvH score -0·2, 95% CI -1·1 to 0·7, SE 0·4).

INTERPRETATION

This study suggests that the optimal prediction of future rates of radiographic progression in patients with rheumatoid arthritis will require an assessment of autoantibodies against multiple post-translationally modified proteins or peptides.

FUNDING

The EU FP7 HEALTH programme, the Scottish Translational Medicine Research Collaboration, and the Chief Scientist Office Scotland.

Rheumatoid Arthritis: Early Diagnosis and Treatment

Rheumatoid arthritis (RA) is a chronic, progressive inflammatory disorder that manifests as a symmetric polyarthritis of small and large joints that may lead to joint and periarticular structural damage and the consequences of systemic inflammation. This overview of early RA examines the unmet needs and challenges in RA, how to best diagnose RA, and pitfalls in early diagnosis and treatment. The rules for referral to a rheumatologist are reviewed. Primary care physicians are at the front line of early diagnosis and need to start disease-modifying therapy as soon as a diagnosis of RA is established.

Gender Differences in Rheumatoid Arthritis: Interleukin-4 Plays an Important Role

Introduction

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by symmetrical peripheral polyarthritis. A large number of studies have shown that RA is characterized by gender differences in clinical manifestations. The purpose of this study is to identify the key molecules of gender differences in patients with RA and to provide new molecular targets for personalized therapy. Material and Methods. The data from GSE55457 were downloaded from the comprehensive gene expression comprehensive database, and two groups (RA vs. No-RA groups, Male-RA vs. Female-RA groups) of differentially expressed genes (EDGs) were obtained by GEO2R. The GO function and KEGG pathway analyses of DEGs were carried out through the plug-in ClueGO in Cytoscape. Based on the STRING online, a protein-protein interaction (PPI) network was constructed. Hub genes were selected from CytoHubba. Through the intersection of the top 10 hub genes in two sets of EDGs, the key genes and related KEGG pathways were found. Quantitative Real-Time PCR and Western blotting analysis were performed for verification.

Results

1230 DEGs were screened between RA and No-RA groups, and 306 DEGs were screened between male and female RA groups. The common key gene of the two groups is IL-4. Between RA group and No-RA group, interleukin-4 (IL-4) participates in cytokine-cytokine receptor interaction, Th1 and Th2 cell differentiation, Th17 cell differentiation, T cell receptor signaling pathway, etc.

Conclusion

This study contributes to the molecular biological mechanism of gender differences in RA. IL-4 may have played an important role.

The Lipid Paradox as a Metabolic Checkpoint and Its Therapeutic Significance in Ameliorating the Associated Cardiovascular Risks in Rheumatoid Arthritis Patients

While the most common manifestations associated with rheumatoid arthritis (RA) are synovial damage and inflammation, the systemic effects of this autoimmune disorder are life-threatening, and are prevalent in 0.5–1% of the population, mainly associated with cardiovascular disorders (CVDs). Such effects have been instigated by an altered lipid profile in RA patients, which has been reported to correlate with CV risks. Altered lipid paradox is related to inflammatory burden in RA patients. The review highlights general lipid pathways (exogenous and endogenous), along with the changes in different forms of lipids and lipoproteins in RA conditions, which further contribute to elevated risks of CVDs like ischemic heart disease, atherosclerosis, myocardial infarction etc. The authors provide a deep insight on altered levels of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TGs) in RA patients and their consequence on the cardiovascular health of the patient. This is followed by a detailed description of the impact of anti-rheumatoid therapy on the lipid profile in RA patients, comprising DMARDs, corticosteroids, anti-TNF agents, anti-IL-6 agents, JAK inhibitors and statins. Furthermore, this review elaborates on the prospects to be considered to optimize future investigation on management of RA and treatment therapies targeting altered lipid paradigms in patients.

Diet as a Modulator of Intestinal Microbiota in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic immune-driven inflammatory disease characterised by synovial inflammation, leading to progressive cartilage and bone destruction, impacting patients' functional capacity and quality of life. Patients with RA have significant differences in gut microbiota composition when compared to controls. Intestinal dysbiosis influences the intestinal barrier strength, integrity and function, and diet is considered the main environmental factor impacting gut microbiota. Over the last few years, researchers have focused on the influence of single components of the diet in the modulation of intestinal microbiota in RA rather than whole dietary patterns. In this review, we focus on how the Mediterranean diet (MD), a whole dietary pattern, could possibly act as an adjuvant therapeutic approach, modulating intestinal microbiota and intestinal barrier function in order to improve RA-related outcomes. We also review the potential effects of particular components of the MD, such as n-3 polyunsaturated fatty acids (PUFAs), polyphenols and fibre.

Screen the Effective Components of Lycopodii herba on Rheumatoid Arthritis with the Aid of Spectrum-Effect Relationship and Uncover its Potential Mechanism

Lycopodii herba (SJC), a traditional Chinese medicine, has the effect of dispelling wind and eliminating dampness (a therapeutic principle and method of traditional Chinese medicine for rheumatoid arthritis), relaxing tendon and activating collaterals. However, the major effective components and its therapeutic mechanism were unclear. In this study, different SJC samples with slightly different compositions were prepared by extracting with different concentrations of ethanol. Then, the therapeutic effects on rheumatoid arthritis (RA) of different SJC samples were evaluated. Finally, the spectrum-effect relationship between UPLC-Q-TOF/MS fingerprints and the effect of RA was explored to screen the effective components. Western blotting was used to study the potential mechanism. The volume of hind paw and the level of RF, TNF-α, and IL-1β were lower after administrating with different SJC samples, compared with the model group. Histopathological findings also confirmed that SJC could relieve the symptoms of RA. Combined with identification of the components in plasm from SJC, lycojaponicumin C, des-N-methyl-α-obscurine, 8β-acetoxy-12β-hydroxy-lycopodine or 8β-acetoxy-11α-hydroxy-lycopodine or 8β-hydroxy-11α-acetoxylycopodine were considered to be the major effective components. The mechanism may be related to AChE/NF-κB signaling pathway. This work provides a general method to screen the potential effective components of herb medicines and would be benefit to understand the mechanism of SJC for the treatment of RA.

Increased primary care use for musculoskeletal symptoms, infections and comorbidities in the years before the diagnosis of inflammatory arthritis

Objectives

Little is known about relevant events in the at-risk phase of rheumatoid arthritis before the development of clinically apparent inflammatory arthritis (IA). The present study assessed musculoskeletal symptoms, infections and comorbidity in future IA patients.

Methods

In a nested case–control study using electronic health records of general practitioners, the frequency and timing of 192 symptoms or diseases were evaluated before a diagnosis of IA, using the International Classification of Primary Care coding system. Cases were 2314 adults with a new diagnosis IA between 2012 and 2016; controls were matched 1:2. The frequency of primary care visits was compared using logistic regression.

Results

The frequency of visits for musculoskeletal symptoms (mostly of shoulders, wrists, fingers and knees) and carpal tunnel syndrome was significantly higher in IA patients vs controls within the final 1.5 years before diagnosis, with ORs of 3.2 (95% CI 2.8 to 3.5), 2.8 (95% CI 2.5 to 3.1) and 2.5 (95% CI 2.2 to 2.8) at 6, 12 and 18 months before diagnosis, respectively. Also, infections (notably of the genital and urinary tracts), IA-comorbidities and chronic diseases were more prevalent in cases than controls, but more evenly spread out over the whole 6-year period before IA. A decision tree was created including all symptoms and diseases.

Conclusion

There was an increased frequency of primary care visits for musculoskeletal symptoms, infections and comorbidities prior to the diagnosis of IA. This diverging trend is present for 4–6 years, but becomes statistically significant 1.5 years before the diagnosis. Validation of these results is warranted.

A cross-sectional study of association of serostatus and extra-articular manifestations in patients with rheumatoid arthritis in a teaching hospital

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disease, which mistakenly attacks the joints and induces the inflammatory changes that thicken the joints (the synovium) resulting in swelling and pain in and around the joints. It causes pain, joint deformity, and also affects the quality of life. The joint is affected symmetrically. It also can affect body systems, such as the cardiovascular, respiratory systems, or other systems, which manifest as extra-articular manifestations. Extra-articular manifestations of RA are documented less in India hence this study was undertaken to correlate RA with extra-articular manifestations as well as its relationship with serostatus in patients with extra-articular manifestations.

MATERIALS AND METHODS

Sixty patients (age between 18-60 years) attending Medicine/Rheumatology outpatient department were included in the study (12 months) who fulfilled the 2010 RA classification criteria laid down by American College of Rheumatology (ACR)/European League against Rheumatism (EULAR) for RA. All the subjects underwent a thorough history, clinical examination, and laboratory investigations. The relevant data were analyzed with appropriate statistical methods after 12 months' duration.

RESULTS

Nearly 68.33% of the subjects were found to have extra-articular manifestations mostly in the age group of 31-40 years with prevalence higher in the female. In the seropositive patients, early morning stiffness (EMS) constitutes 63.82% of the total extra-articular manifestations in the patients followed by anemia (38.29%) and peripheral neuropathy (34.04%). On the other hand, in the seronegative cases, EMS (61.53%) followed by anemia (23.07), peripheral neuropathy (15.38%), and keratoconjunctivitis sicca (15.38%). Extra-articular manifestations in seropositive patients have a statistically significant relationship with the increase in the duration of the disease.

CONCLUSION

Extra-articular manifestations need to be looked carefully as it is associated with more severe disease. Seropositivity and extra-articular manifestations both usually indicate that the RA is more severe and may affect the quality of life.

Metabolic Checkpoints in Rheumatoid Arthritis

Several studies have highlighted the interplay between metabolism, immunity and inflammation. Both tissue resident and infiltrating immune cells play a major role in the inflammatory process of rheumatoid arthritis (RA) via the production of cytokines, adipo-cytokines and metabolic intermediates. These functions are metabolically demanding and require the most efficient use of bioenergetic pathways. The synovial membrane is the primary site of inflammation in RA and exhibits distinctive histological patterns characterized by different metabolism, prognosis and response to treatment. In the RA synovium, the high energy demand by stromal and infiltrating immune cells, causes the accumulation of metabolites, and adipo-cytokines, which carry out signaling functions, as well as activating transcription factors which act as metabolic sensors. These events drive immune and joint-resident cells to acquire pro-inflammatory effector functions which in turn perpetuate chronic inflammation. Whether metabolic changes are a consequence of the disease or one of the causes of RA pathogenesis is still under investigation. This review covers our current knowledge of cell metabolism in RA. Understanding the intricate interactions between metabolic pathways and the inflammatory and immune responses will provide more awareness of the mechanisms underlying RA pathogenesis and will identify novel therapeutic options to treat this disease.

Signaling of the Purinergic System in the Joint

The joint is a complex anatomical structure consisting of different tissues, each with a particular feature, playing together to give mobility and stability at the body. All the joints have a similar composition including cartilage for reducing the friction of the movement and protecting the underlying bone, a synovial membrane that produces synovial fluid to lubricate the joint, ligaments to limit joint movement, and tendons for the interaction with muscles. Direct or indirect damage of one or more of the tissues forming the joint is the foundation of different pathological conditions. Many molecular mechanisms are involved in maintaining the joint homeostasis as well as in triggering disease development. The molecular pathway activated by the purinergic system is one of them.The purinergic signaling defines a group of receptors and intermembrane channels activated by adenosine, adenosine diphosphate, adenosine 5’-triphosphate, uridine triphosphate, and uridine diphosphate. It has been largely described as a modulator of many physiological and pathological conditions including rheumatic diseases. Here we will give an overview of the purinergic system in the joint describing its expression and function in the synovium, cartilage, ligament, tendon, and bone with a therapeutic perspective.

Population-based estimates of humoral autoimmunity from the U.S. National Health and Nutrition Examination Surveys, 1960-2014

Objective

Based on US National Health and Nutrition Examination Survey (NHANES) data, we attempted to provide an unbiased, population-based estimate of autoantibody prevalence overall and by age and sex.

Methods

US autoantibody prevalence estimates for detectable rheumatoid factor, anti-thyroglobulin, anti-thyroperoxidase, anti-transglutaminase, anti-endomysial, anti-GAD65, antinuclear autoantibodies, and autoantibodies to extractable nuclear antigens were estimated from the 1960–1962 National Health Examination Survey, NHANES III (1988–1994), and the NHANES 1999–2014 cross-sectional surveys. Survey design variables and sample weights were used to account for differential probabilities of selection within the complex survey design. Data analysis used SAS^TM and SUDAAN^™ software. US Census Bureau data were used to estimate the absolute numbers of persons with autoantibodies.

Results

NHANES III data show that the overall US prevalence of having a detectable serum autoantibody is substantial in adults, in both women and men. Thyroid autoantibodies were present in 18% of US adults (31 million persons) including 10% of younger adults and 25% of older persons. Overall autoantibody prevalences increased significantly with age: 32% of US adults 60+ years of age (12.8 million persons) had at least one of the four autoantibodies rheumatoid factor, anti-thyroglobulin, anti-thyroperoxidase, or anti-tissue transglutaminase. Older women had higher levels of autoantibodies, but this was a relative difference. Autoantibody prevalence in both sexes was substantial (women 39%; men 22%). Fourteen percent of adults 60+ years of age have multiple autoantibodies.

Conclusions

Autoantibodies are present in a significant fraction of the general population, especially in older adults and women relative to men. Although all known clinically significant autoantibodies were not analyzed, these data provide an important population perspective on the scope and magnitude of humoral autoimmunity in the US. This is vital for prevention efforts to reduce autoimmune disease and helps clarify the potential impact of autoimmunity on the general population.

Dysregulation of T Follicular Helper Cells in Lupus

Although multiple and overlapping mechanisms are ultimately responsible for the immunopathology observed in patients with systemic lupus erythematosus, autoreactive Abs secreted by autoreactive plasma cells (PCs) are considered to play a critical role in disease progression and immunopathology. Given that PCs derive from the germinal centers (GC), long-term dysregulated GC reactions are often associated with the development of spontaneous autoantibody responses and immunopathology in systemic lupus erythematosus patients. In this review, we summarize the emerging evidence concerning the roles of T follicular helper cells in regulating pathogenic GC and autoreactive PC responses in lupus.

Vitamin D, Autoimmune Disease and Rheumatoid Arthritis

Vitamin D has been reported to influence physiological systems that extend far beyond its established functions in calcium and bone homeostasis. Prominent amongst these are the potent immunomodulatory effects of the active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3). The nuclear vitamin D receptor (VDR) for 1,25-(OH)2D3 is expressed by many cells within the immune system and resulting effects include modulation of T cell phenotype to suppress pro-inflammatory Th1 and Th17 CD4+ T cells and promote tolerogenic regulatory T cells. In addition, antigen-presenting cells have been shown to express the enzyme 1α-hydroxylase that converts precursor 25-hydroxyvitamin D3 (25-OHD3) to 1,25-(OH)2D3, so that immune microenvironments are able to both activate and respond to vitamin D. As a consequence of this local, intracrine, system, immune responses may vary according to the availability of 25-OHD3, and vitamin D deficiency has been linked to various autoimmune disorders including rheumatoid arthritis (RA). The aim of this review is to explore the immune activities of vitamin D that impact autoimmune disease, with specific reference to RA. As well as outlining the mechanisms linking vitamin D with autoimmune disease, the review will also describe the different studies that have linked vitamin D status to RA, and the current supplementation studies that have explored the potential benefits of vitamin D for prevention or treatment of RA. The overall aim of the review is to provide a fresh perspective on the potential role of vitamin D in RA pathogenesis and treatment.

Host-microbiota interactions in rheumatoid arthritis

The gut microbiota has been proposed to be an important environmental factor in the development of rheumatoid arthritis (RA). Here, we review a growing body of evidence from human and animal studies that supports the hypothesis that intestinal microbiota play a role in RA. Previous studies from we and others showed an altered composition of the microbiota in early RA patients. A recent study demonstrated that Prevotella species are dominant in the intestine of patients in the preclinical stages of RA. In addition, Prevotella-dominated microbiota isolated from RA patients contributes to the development of Th17 cell-dependent arthritis in SKG mice. Moreover, it was reported that periodontal bacteria correlates with the pathogenesis of RA. In this review, we discuss the link between oral bacteria and the development of arthritis. However, many questions remain to be elucidated in terms of molecular mechanisms for the involvement of intestinal and oral microbiota in RA pathogenesis.

Microbes living in the gut and mouth have been implicated in the development of rheumatoid arthritis (RA) and treatments that promote the growth of healthier bacterial communities may help weaken this autoimmune disease. Yuichi Maeda and Kiyoshi Takeda from Osaka University, Japan, review data from mice and humans linking RA to altered microbial compositions in the gut. They focus on a particular bacterium called Prevotella copri, which is found at much higher numbers in the gastrointestinal tracts of people with newly diagnosed RA than in those without the disease. Certain mouth-dwelling bacteria may also help exacerbate RA through the induction of antibodies directed against the host. The exact molecular mechanism by which gut and oral microbes contribute to RA remains unclear.

Nomenclature for the Phases of the Development of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a common immune-mediated inflammatory disease. Research on RA is increasingly focused on the earliest stages of the disease, and has provided strong evidence that clinical signs and symptoms may be preceded by a preclinical phase during which evidence of systemic autoimmunity may be present. To facilitate research in this area, a number of international initiatives have proposed definitions of the phases of disease leading up to RA. The first of these initiatives was the European League Against Rheumatism's (EULAR) set of recommendations on terminology in persons at risk for RA, which suggested that the "at-risk phases" be described in terms of patients variably having: (A) genetic risk factors for RA; (B) environmental risk factors for RA; (C) systemic autoimmunity associated with RA; (D) symptoms without clinical arthritis; and (E) unclassified arthritis. The phrase clinically suspect arthralgia (CSA) is now widely used and can be regarded as describing a subgroup of patients in phase D. A definition of CSA was recently proposed by a EULAR taskforce, and primary research has begun to explore the full range of symptoms, as well as their sensitivity and specificity alone and in combination with other factors, that characterize this phase. Similarly, immune abnormalities at mucosal and others sites that precede and/or are associated with the onset of musculoskeletal symptoms are being increasingly studied and understood. Whether some of these at-risk phases, in particular CSA, represent entities meriting their own classification criteria is an essential area for consensus and will be discussed.

Searching for a prodrome for rheumatoid arthritis in the primary care record: A case-control study in the clinical practice research datalink

BACKGROUND

Rheumatoid arthritis (RA) has articular and non-articular manifestations. Early, intensive treatment has substantial benefit for both. This requires patients be identified as soon as symptoms develop.

OBJECTIVES

To determine whether selected signs and symptoms can be identified in the primary care records of patients prior to a formal diagnosis of RA being made and, if so, how early they can be identified.

METHODS

A case-control study was constructed within the UK Clinical Practice Research Datalink (CPRD). 3577 individuals with 'definite' RA, were matched to 14,287 individuals without inflammatory arthritis. An index date was established (i.e., date general practitioner (GP) first appeared to suspect RA). Rates of consultation and consultations for suspected early RA symptoms were compared in cases and controls in the two years prior to the index date using conditional logistic regression, adjusted for number of consultations.

RESULTS

The mean (standard deviation) age of participants was 58.8 (14.5) years and 66.8% were female. Rates of any consultation were significantly higher in RA cases than in controls for at least two years prior to the index date. Cases were more likely to have a pre-diagnosis coded consultation for joint, and particularly hand symptoms (aOR 11.44 (9.60, 13.63)), morning stiffness (8.10 (3.54, 18.5)), carpal tunnel syndrome (4.57 (3.54, 5.88)) and other non-articular features.

CONCLUSIONS

In patients who develop RA, GP consultation rates are higher for at least two years prior to the first recorded suspicion of RA. This study highlights symptoms that should raise a GP's index of suspicion for RA.

The Role of High-Mobility Group Box-1 and Its Crosstalk with Microbiome in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, definitely disabling, and potentially severe autoimmune disease. Although an increasing number of patients are affected, a key treatment for all patients has not been discovered. High-mobility group box-1 (HMGB1) is a nuclear protein passively and actively released by almost all cell types after several stimuli. HMGB1 is involved in RA pathogenesis, but a convincing explanation about its role and possible modulation in RA is still lacking. Microbiome and its homeostasis are altered in patients with RA, and the microbiota restoration has been proposed to patients with RA. The purpose of the present review is to analyze the available evidences regarding HMGB1 and microbiome roles in RA and the possible implications of the crosstalk between the nuclear protein and microbiome in understanding and possibly treating patients affected by this harmful condition.