The genetics of rheumatoid arthritis

Global, regional, and national burden and trends of rheumatoid arthritis among the elderly population: an analysis based on the 2021 Global Burden of Disease study

Background

Rheumatoid arthritis (RA) is an autoimmune and inflammatory disease. In elderly patients, the disease progresses more rapidly, involves more complications, and places a greater burden on health. Currently, there is a lack of studies investigating the disease burden of RA in the elderly population.

Methods

We analyzed data on elderly rheumatoid arthritis from the Global Burden of Disease (GBD) database for 1990-2021, focusing on three main indicators: prevalence, incidence, and Disability-Adjusted Life Years (DALYs). Percentage change and the estimated annual percentage change (EAPC) were used to evaluate the trends in the disease burden.

Results

In 2021, the global prevalence cases, incidence cases, and DALYs of elderly RA were 7,919,136, 334,291, and 1,549,877, representing increases of 157.59%, 169.71%, and 116.53% compared to 1990. Both the prevalence rate and incidence rate increased, with EAPCs of 0.54 (95% CI: 0.5, 0.58) and 0.75 (95% CI: 0.7, 0.79), respectively. Notably, the prevalence rate in females was 2.2 times higher than that in males. The DALY rate showed a slight decline. Among the five Socio-demographic Index (SDI) regions, the High SDI region had the highest prevalence cases, incidence cases, and DALYs in 2021, with 2,821,305, 114,994, and 483,579, respectively, accounting for 36%, 34%, and 32% of the global totals. This region also recorded the highest prevalence and incidence rates. In contrast, the Low SDI and Low-middle SDI regions exhibited the fastest growth in both prevalence and incidence cases as well as rates. The highest prevalence cases and incidence rate were observed in the 65-69 age group. Decomposition analysis revealed that the rising disease burden was primarily attributable to the growth of the global elderly population.

Conclusions

Between 1990 and 2021, the global burden of rheumatoid arthritis in the elderly population increased. The High SDI region experienced the highest disease burden. In contrast, the Low and Low-middle SDI regions showed the most rapid growth in disease burden. Females exhibited a higher burden compared to males, with the highest burden observed in the 65-69 age group. Early diagnosis and treatment in elderly patients are essential to mitigating adverse outcomes and reducing the burden.

Investigating the causal relationship between rheumatoid arthritis and cardiovascular disease: A Mendelian randomization study

OBJECTIVE

Previous research has revealed a positive correlation between rheumatoid arthritis (RA) and cardiovascular diseases, but the causal relationship is unclear. This study applies Mendelian randomization to examine whether RA causally contributes to the likelihood of various cardiovascular diseases, such as heart failure, coronary artery disease, and atrial fibrillation.

METHODS

Using genome-wide association data, we conducted a univariable MR (UVMR) analysis to evaluate the causal impact of RA on CVD, primarily utilizing the inverse variance weighted method. Additional MR methods were used to test the robustness of the results. Multivariable MR (MVMR) was applied to explore potential confounders.

RESULTS

In the European population, genetically predicted RA had a harmful causal effect on HF, with the IVW analysis indicating an OR of 1.06 (95% CI: 1.02-1.10, P < 0.01) based on 23 SNPs. No causal relationships were found between RA and other CVDs. The MVMR analysis did not identify significant causal impact of rheumatoid arthritis on HF after controlling for traditional risk factors. In the Asian population, RA was associated with an adverse effect on AF, with the IVW method reporting an OR of 1.20 (95% CI: 1.01-1.41, P = 0.03) for 5 SNPs. No other CVD relationships were found.

CONCLUSIONS

Our MR analysis indicates that genetic susceptibility to rheumatoid arthritis increases the likelihood of heart failure in European populations and atrial fibrillation in East Asian populations. However, established CVD risk factors, such as smoking, overweight, and physical inactivity, remain critically important in the management of RA. Key Points • Multiple studies have highlighted a marked increase in the cardiovascular event risk among individuals with RA. However, additional RCTs are needed for confirmation. • We applied Mendelian randomization to explore the potential causal relationship between rheumatoid arthritis and cardiovascular conditions. The findings demonstrated a causal link between RA and heart failure among European populations, as well as an association between RA and atrial fibrillation in East Asian groups. • Further adjustments using multivariable Mendelian randomization to account for the influence of traditional cardiovascular risk factors revealed that the causal association between RA and heart failure disappeared.

New thoughts on the gut-immune axis of arthritis

Arthritis is associated with varying degrees of intestinal inflammation and microbiota dysbiosis, leading to the 'gut-joint axis hypothesis' in which intestinal and joint inflammation are suggested to be interconnected through immune-microbiota interactions. While clinical observations support this, causality remains uncertain. Rodent models have provided insights into potential mechanisms by uncovering microbial influences and immune pathways that either connect or uncouple gut and joint inflammation. Based on recent findings, we propose the 'immune hypersensitivity hypothesis' whereby central immune hyper-reactivity can independently drive joint inflammation via local sterile triggers, and gut inflammation via microbial triggers. We argue that this suggests a more nuanced role of the microbiota in arthritis pathogenesis that varies according to the predominant immune mechanisms in disease subtypes. We explore gut-immune interactions in arthritis, highlight ongoing challenges, and propose future research directions.

Nanostructured lipid carriers in Rheumatoid Arthritis: treatment, advancements and applications

Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects the joints and causes pain, swelling, and deformity. Current treatments, including nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and disease-modifying antirheumatic drugs, often have limited efficacy and adverse side effects. Nanostructured lipid carriers (NLCs) are promising drug delivery agents for treating RA. NLCs are comprised of solid and liquid lipids, forming a nanostructured matrix that enhances drug solubility, stability, and controlled release. They offer advantages over traditional carriers such as improved skin penetration, increased bioavailability, and reduced systemic side effects. Topical NLC formulations show improved stability and skin absorption, targeting drugs specifically to the affected joints, thus reducing the required dose and systemic exposure. Studies on NLCs for delivering anti-inflammatory and antirheumatic drugs, such as methotrexate, indomethacin, and curcumin, in RA animal models indicate the potential for improved therapeutic efficacy and safety. NLCs represent a promising approach for targeted RA drug delivery, offering better efficacy, fewer side effects, and higher patient compliance. However, further research is needed to optimize NLC formulations and evaluate their clinical efficacy and safety in RA patients. The development of NLC-based drug delivery systems for RA treatment may lead to more effective and well-tolerated therapies, thereby improving the quality of life of patients with this debilitating disease.

OPG/RANK/RANKL Single-Nucleotide Polymorphisms in Rheumatoid Arthritis: Associations with Disease Susceptibility, Bone Mineral Density, and Clinical Manifestations in a Chinese Han Population

Objective

The osteoprotegerin (OPG)/receptor activator of nuclear factor-κB (RANK)/receptor activator of nuclear factor-κB ligand (RANKL) system plays a pivotal role in the balance between osteoblasts and osteoclasts and is closely related to the pathogenesis of rheumatoid arthritis (RA). The present study aimed to clarify the associations of OPG/RANK/RANKL gene single-nucleotide polymorphisms (SNPs) with disease susceptibility, bone mineral density (BMD), and clinical manifestations in RA patients.

Methods

A case-control study including 319 RA patients and 330 healthy controls was conducted. All subjects were genotyped for rs4355801 and rs1023968 in OPG, rs10805033 in RANK, and rs9533155 and rs875625 in RANKL. BMD and clinical manifestations were recorded.

Results

An association was found between OPG rs4355801 and risk of RA. In recessive models, the GG genotype of rs4355801 was associated with an increased risk of RA compared with the AA/AG genotypes (OR=1.679, 95% CI: 1.062-2.655, p=0.025). A correlation between RANKL rs9533155 and BMD was found in RA patients. Patients with the GG genotype (n=108) in RANKL rs9533155 had the more decreased BMD values at lumbar level 2 (t=3.424, p=0.009), lumbar level 3 (t=3.171, p=0.019), lumbar level 4 (t=4.187, p=0.001), and total lumbar levels 2-4 (t=2.989, p=0.021) compared with CC+GC genotypes. No associations were found between the OPG, RANK, and RANKL SNPs and clinical manifestations of RA (all p>0.05). Logistic regression analysis indicated that older age (OR=1.057, 95% CI: 1.017-1.099, p=0.005), higher HAQ (OR=2.786, 95% CI: 1.329-5.841, p=0.007), and GG genotype of rs9533155 (OR=3.242, 95% CI: 1.254-8.376, p=0.015) were risk factors of lumbar osteoporosis onset in RA patients.

Conclusion

In summary, OPG rs4355801 is associated with susceptibility to RA and RANKL rs9533155 GG genotype potentially contributes to decreased BMD in RA. Studies with larger sample sizes are needed to confirm the present findings.

Rheumatoid arthritis: a comprehensive overview of genetic markers, emerging therapies, and personalized medicine

Rheumatoid arthritis (RA) is a prevalent autoimmune disorder marked by chronic inflammatory arthritis and systemic effects. The etiology of RA is complex, involving genetic factors like HLA-DR4 and HLA-DR1, as well as environmental influences, particularly smoking, which heightens disease risk. Affecting approximately 1% of the global population, RA is associated with considerable morbidity and mortality, with its prevalence expected to increase due to demographic shifts, especially in certain regions. RA symptoms commonly manifest between ages 35 and 60 but can also affect children under 16 in cases of juvenile RA. Symptoms include prolonged joint stiffness, pain, fatigue, and, in advanced cases, joint deformities. Current treatment approaches involve disease-modifying antirheumatic drugs, biologics, and glucocorticoids to manage symptoms and slow disease progression, though these treatments often present limitations due to adverse effects and varied patient response. The identification of genetic markers, such as HLA-DRB1 and PTPN22, supports the growing emphasis on personalized treatment strategies that account for genetic and lifestyle factors. Non-pharmacological approaches - diet adjustments, physical activity, and stress management - are increasingly valued for their complementary role in RA management. Lifestyle interventions, including whole-food, plant-based diets and physical therapy, show promise in reducing inflammation and improving joint function. Technological advancements, like telemedicine, mobile health applications, and artificial intelligence, are enhancing RA diagnosis and treatment, making care more precise and accessible. Despite these advancements, RA remains incurable, necessitating continued research into novel therapeutic targets and approaches. A comprehensive, patient-centered approach that integrates lifestyle modifications, preventive strategies, and innovative treatments is essential for improving RA management and patient outcomes.

Exploration and Identification of Potential Biomarkers and Immune Cell Infiltration Analysis in Synovial Tissue of Rheumatoid Arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is a prevalent autoimmune disease with synovial inflammation and hyperplasia, which can potentially cause degradation of articular cartilage, ultimately causing joint deformity, and impaired function. However, exact mechanisms underlying RA remain incompletely understood. This study seeks to uncover genomic signatures and potential biomarkers of RA, along with exploring the biological processes involved.

METHODS

Six microarray datasets from RA patients, osteoarthritis (OA) and healthy controls (HC) of synovial tissue were obtained from the Gene Expression Omnibus (GEO) database for integrated analysis. Differentially expressed genes (DEGs) between groups were identified by "limma" package. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were carried out. Protein-protein interaction (PPI) network was analyzed by STRING and presented by Cytoscape. Weighted gene co-expression network analysis (WGCNA) was conducted to discover and construct the co-expression gene modules correlated with clinical phenotype. CytoHubba and MCODE were utilized for screening hub genes. Additionally, immune cell infiltration analysis was conducted utilizing CIBERSORT algorithm. The correlation of hub genes with immune cells were examined through Pearson Correlation Analysis.

RESULTS

The overlapped 92 up-regulated genes were determined between RA versus normal controls and RA versus OA, which were primarily enriched in immune response, lymphocyte activation, and chemokine signaling pathway. By integrating WGCNA, Cytohubba and MCODE algorithms, 16 hub genes were identified including CXCL13, ITK, CXCL9, CCR5, CCR7, NKG7, CCR7, and CD52. We validated the diagnostic significance of these markers in RA by qRT-PCR. Moreover, the analysis of immune cell infiltration demonstrated a positive association between these hub genes with B cell naïve, plasma cell, T cells follicular helper, and macrophages M1. The abundance of these cells was markedly greater in RA compared to OA and normal controls.

CONCLUSION

This research ultimately identified 5 potential diagnostic biomarkers of RA in the synovial tissue, namely NKG7, CD52, ITK, CXCL9, and GZMA. These findings have enhanced our comprehension of RA pathogenesis and identified promising diagnostic and therapeutic targets of RA.

Association of PADI4 Gene Polymorphisms With Susceptibility to Rheumatoid Arthritis: Evidence From 24 Case-Control Studies

This study aims to investigate the association of rs11203366, rs11203367, rs874881, rs2240340 and rs1748033 polymorphisms of protein-arginine deiminase type 4 (PADI4) gene with the risk of rheumatoid arthritis (RA) through a meta-analysis that was followed with a bioinformatics approach. The data were collected from reputable articles and underwent quantitative analysis, followed by in silico analysis using some bioinformatics tools. The results showed that rs874881 polymorphism in Latino (G vs. C: OR = 1.35, 95% CI = 1.11-1.65, p = 0.003; GG + CG vs. CC: OR = 2.02, 95% CI = 1.41-2.89, p = 0.0001; CG vs. CC + GG: OR = 1.38, 95% CI = 1.04-1.83, p = 0.027; GG vs. CC: OR = 2.09, 95% CI = 1.35-3.23, p = 0.001; CG vs. CC: OR = 1.98, 95% CI = 1.36-2.87, p = 0.00033) and rs1748033 in Caucasian population (T vs. C: OR = 1.25, 95% CI = 1.07-1.45, p = 0.005; TT vs. CT + CC: OR = 1.34, 95% CI = 1.09-1.64, p = 0.005, TT + CT vs. CC: OR = 1.26, 95% CI = 1.09-1.44, p = 0.001; TT vs. CC: OR = 1.59, 95% CI = 1.13-2.23, p = 0.007; CT vs. CC: OR = 1.20, 95% CI: 1.04-1.39, p = 0.015) are associated with increased risk of RA. Moreover, rs11203366 (G vs. A: OR = 1.46, 95% CI = 1.19-1.78, p = 0.0002, GG vs. AG + AA: OR = 1.42, 95% CI = 1.01-2.01, p = 0.043; GG + AG vs. AA: OR = 2.03, 95% CI = 1.45-2.86, p = 0.00004; GG vs. AA: OR = 2.29, 95% CI = 1.49-3.51, p = 0.0002; AG vs. AA: OR = 1.93, 95% CI = 1.35-2.76, p = 0.0003) and rs11203367 (T vs. C: OR = 1.50, 95% CI = 1.23-1.83, p = 0.00007; TT vs. CT + CC: OR = 1.56, 95% CI = 1.12-2.18, p = 0.009; TT + CT vs. CC: OR = 2.02, 95% CI = 1.43-2.84, p = 0.00007, TT vs. CC: OR = 2.43, 95% CI = 1.59-3.71, p = 0.0004; CT vs. CC: OR = 1.86, 95% CI = 1.30-2.68, p = 0.0007) had an impact in the Latino population. Bioinformatics tools showed the effect of these polymorphisms on gene function. These findings suggest that rs11203366, rs11203367, rs874881 and rs1748033 polymorphisms may be genetic risk factors for RA. Moreover, differences between populations suggest that ethnicity may play an important role in the effect of these polymorphisms on RA risk.

Cellular senescence-associated genes in rheumatoid arthritis: Identification and functional analysis

Rheumatoid arthritis (RA), a long-term autoinflammatory condition causing joint damage and deformities, involves a multifaceted pathogenesis with genetic, epigenetic, and immune factors, including early immune aging. However, its precise cause remains elusive. Cellular senescence, a hallmark of aging marked by a permanent halt in cell division due to damage and stress, is crucial in aging and related diseases. In our study, we analyzed RA microarray data from the Gene Expression Omnibus (GEO) and focused on cellular senescence genes from the CellAge database. We started by selecting five RA datasets from GEO. Next, we pinpointed 29 differentially expressed genes (DEGs) linked to cellular senescence in RA, aligning them with genes from CellAge. We explored the roles of these DEGs in cellular senescence through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. We then pinpointed three key genes (DHX9, CYR61, and ITGB) using random forest and LASSO Cox regression machine learning techniques. An integrated diagnostic model was created using these genes. We also examined the variance in immune cell infiltration and immune checkpoint gene expression between RA and normal samples. Our methodology's predictive accuracy was confirmed in external validation cohorts. Subsequently, RA samples were classified into three distinct subgroups based on the cellular senescence-associated DEGs, and we compared their immune landscapes. Our findings reveal a significant impact of cellular senescence-related DEGs on immune cell infiltration in RA samples. Hence, a deeper understanding of cellular senescence in RA could offer new perspectives for diagnosis and treatment.

Association between red blood cell distribution width and genetic risk in patients with rheumatoid arthritis: a prospective cohort study and Mendelian randomization analysis

OBJECTIVE

Elevated red blood cell distribution width (RDW) is associated with increased risk of rheumatoid arthritis (RA), but the potential interactions of RDW with genetic risk of incident RA remain unclear. This study aimed to investigate the associations between RDW, genetics, and the risk of developing RA.

METHODS

We analysed data from 145,025 healthy participants at baseline in the UK Biobank. The endpoint was diagnosed rheumatoid arthritis (ICD-10 codes M05 and M06). Using previously reported results, we constructed a polygenic risk score for RA to evaluate the joint effects of RDW and RA-related genetic risk. Two-sample mendelian randomization and bayesian colocalization were used to infer the causal relation between them.

RESULTS

A total of 675 patients with RA were enrolled and had a median followed up of 5.1 years, with an incidence rate of 0.57/1000 person-years. The hazard ratio of RA was 1.89 (95% CI: 1.45, 2.47) in highest RDW quartile group compared with the lowest RDW quartile group. Individuals within the top quintile of PRS showed a significantly high risk of RA. Moreover, Participants with high genetic risk and those in highest RDW group exhibited a significantly elevated hazard ratio (7.67, 95% CI: 3.98, 14.81), as opposed to participants with low genetic risk and those in lowest RDW group. Interactions between PRS and RDW on the multiplicative and additive scale were observed. Mendelian randomization provided suggestive evidence of a bi-directional causal relationship between RDW and RA. Loci near IL6R, IL1RN, FADS1/FADS2, UBE2L3 and HELZ2 showed colocalization.

CONCLUSION

Increased RDW is associated with elevated risk of incident RA especially in the high genetic risk populations, but only suggestive evidence supports a causal relationship between them.

An erythrocyte macrocytosis by methotrexate is associated with early initiation of biologic or targeted synthetic agents in patients with rheumatoid arthritis

Objective

An association between increased erythrocyte mean corpuscular volume (MCV) and treatment response in patients with inflammatory arthritis receiving methotrexate (MTX) has been reported. We investigated the frequency of red blood cell (RBC) macrocytosis and its clinical implications regarding the initiation of biological or targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) in patients starting MTX for rheumatoid arthritis (RA).

Methods

RBC macrocytosis (MCV >100 fL) and clinical characteristics were retrospectively examined in 1,156 patients starting MTX for RA. Multivariable logistic regression analyses were performed to identify the independent predictors of RBC macrocytosis. The initiation of b/tsDMARDs was assessed using a multivariable Cox proportional hazards regression model.

Results

RBC macrocytosis was observed in 21.6% of RA patients over 35 [8, 89] months following MTX initiation and was persistent in 63.6% of the patients during MTX treatment. Anemia coexisted in only 20.0% of the patients with RBC macrocytosis. The occurrence of RBC macrocytosis was independently associated with age, MTX dose, and concomitant use of sulfasalazine or leflunomide (all p<0.001). A higher dose of MTX and double- or triple-DMARDs therapy were more frequently used in the group with RBC macrocytosis than in the group with normal MCV. Patients experiencing RBC macrocytosis were more likely to use b/tsDMARDs (hazard ratio 1.45 [95% confidence interval 1.13, 1.87], p=0.003).

Conclusion

RBC macrocytosis was possibly associated with the use of b/tsDMARD and could be a supplementary marker for assessing MTX resistance.

Genetic Risk Scores for the Clinical Rheumatologist

BACKGROUND/HISTORICAL PERSPECTIVE

The advent of genome-wide sequencing and large-scale genetic epidemiological studies has led to numerous opportunities for the application of genetics in clinical medicine. Leveraging this information toward the formation of clinically useful tools has been an ongoing research goal in this area. A genetic risk score (GRS) is a measure that attempts to estimate the cumulative contribution of established genetic risk factors toward an outcome of interest, taking into account the cumulative risk that each of these individual genetic risk factors conveys. The purpose of this perspective is to provide a systematic framework to evaluate a GRS for clinical application.

SUMMARY OF CURRENT LITERATURE

Since the initial polygenic risk score methodology in 2007, there has been increasing GRS application across the medical literature. In rheumatology, this has included application to rheumatoid arthritis, gout, spondyloarthritis, lupus, and inflammatory arthritis.

MAJOR CONCLUSIONS

GRSs are particularly relevant to rheumatology, where common diseases have many complex genetic factors contributing to risk. Despite this, there is no widely accepted method for the critical application of a GRS, which can be a particular challenge for the clinical rheumatologist seeking to clinically apply GRSs. This review provides a framework by which the clinician may systematically evaluate a GRS.

FUTURE RESEARCH DIRECTIONS

As genotyping becomes more accessible and cost-effective, it will become increasingly important to recognize the clinical applicability of GRSs and identify those of the highest utility for patient care. This framework for the evaluation of a GRS will also help ensure reliability among GRS research in rheumatology, thereby helping to advance the field.

Genetic predisposition to sarcoidosis

Sarcoidosis is a complex systemic disease with clinical heterogeneity based on varying phenotypes and natural history. The detailed etiology of sarcoidosis remains unknown, but genetic predisposition as well as environmental exposures play a significant role in disease pathogenesis. We performed a comprehensive review of germline genetic (DNA) and transcriptomic (RNA) studies of sarcoidosis, including both previous studies and more recent findings. In this review, we provide an assessment of the following: genetic variants in sarcoidosis susceptibility and phenotypes, ancestry- and sex-specific genetic variants in sarcoidosis, shared genetic architecture between sarcoidosis and other diseases, and gene-environment interactions in sarcoidosis. We also highlight the unmet needs in sarcoidosis genetic studies, including the pressing requirement to include diverse populations and have consistent definitions of phenotypes in the sarcoidosis research community to help advance the application of genetic predisposition to sarcoidosis disease risk and manifestations.

The Causal Relationship Between Genetically Determined Plasma Metabolites and Rheumatoid Arthritis

BACKGROUND

Presently, research examining the impact of plasma metabolites on rheumatoid arthritis (RA) is scarce. We utilized a bidirectional two-sample Mendelian randomization (MR) analysis to explore the potential causal link between 1400 plasma metabolites and RA.

METHODS

We performed a two-sample MR analysis to assess the causal association between 1400 plasma metabolites and RA. The primary method of two-sample MR Analysis was the Inverse Variance Weighted (IVW) model, and the secondary methods were the Weighted Median (WM) and MR Egger methods. We conducted sensitivity analyses using Cochran's Q test, MR-Egger intercept test, MR-PRESSO, and Leave-One-Out analyses. Steiger test was used for validation of the metabolites. The main results were validated in the UK Biobank.

RESULTS

In the discovery dataset, 60 metabolites were identified as significantly associated with the onset of RA. A notable finding was the strong correlation between Valve levels and RA risk, showing the highest positive correlation (OR [95% CI]: 1.361 (1.112, 1.667), p = 0.0028). Subsequent analysis of the validation dataset revealed 46 metabolites linked to RA, with X-22771 levels displaying the strongest positive association (OR [95% CI]: 1.002 (1.00, 1.004), p = 0.037). Notably, Glycohydrocolate levels exhibited a protective effect on RA in both datasets. Specifically, the effect size in the initial dataset was (OR [95% CI]:0.867 (0.753, 1.000), p = 0.050), whereas in the validation dataset, the effect was weaker (OR [95% CI]: 0.999 (0.997, 1.000), p = 0.048). These findings were further validated through a series of sensitivity analyses, affirming their robustness and reliability.

CONCLUSIONS

This study highlights a strong correlation between elevated Valine levels and an increased risk of RA, as well as potential protective effects of Glycohydrohorate in independent datasets.

The importance of functional genomics studies in precision rheumatology

Rheumatic diseases, those that affect the musculoskeletal system, cause significant morbidity. Among risk factors of these diseases is a significant genetic component. Recent advances in high-throughput omics techniques now allow a comprehensive profiling of patients at a genetic level through genome-wide association studies. Without functional interpretation of variants identified through these studies, clinical insight remains limited. Strategies include statistical fine-mapping that refine the list of variants in loci associated with disease, whilst colocalization techniques attempt to attribute function to variants that overlap a genetically active chromatin annotation. Functional validation using genome editing techniques can be used to further refine genetic signals and identify key pathways in cell types relevant to rheumatic disease biology. Insight gained from the combination of genetic studies and functional validation can be used to improve precision medicine in rheumatic diseases by allowing risk prediction and drug repositioning.

Prevention of rheumatoid arthritis using a familial predictive medicine approach

Most of the chronic-degenerative diseases deserve a very early recognition of symptoms and signs for the earliest secondary prevention, which could be also very useful in many cases for the most precocious clinical approach. The periodic monitoring of a subject at risk of a specific disease, because of genomic predisposition by predictive medicine approach, may help to earlier detection of onset and/or the progression of the pathology itself, through intra-individual monitoring. This is particularly the case of rheumatoid arthritis (RA) for which an early diagnosis is undoubtedly the first step to ensure the most proper therapy for the patient. Thus, the earlier identification of individuals at high risk of RA could lead to ultra-preventive strategies to start for the best lifestyle performances and/or for any other effective therapeutic interventions to contrast the onset, and/or the evolution of the putative RA. This will also optimize both costs and medical resources, according to the health care policies of many countries.

Biomechanical determinants of rheumatoid arthritis severity and excess cardiovascular disease: common origins of two complex diseases

OBJECTIVES

The determinants of rheumatoid arthritis (RA) severity and excess cardiovascular disease (CVD) are incompletely understood. Biomechanical factors are known to influence RA severity. Articular stiffness correlates with arterial and skin stiffness. This study explored the hypothesis that constitutional stiffness is a common determinant of RA severity and excess CVD.

METHODS

Fifty-eight patients with anti-CCP antibody (ACPA) positive RA and 57 controls were enrolled noting age, sex, body mass index, alcohol and tobacco exposure, Shared Epitope status and in RA disease duration, disease activity, ACPA titre and radiographic damage. Severe RA was defined as radiographic progression >1.3 mSharp points/year or requiring biological disease-modifying antirheumatic drugs (bDMARDs). Articular stiffness (Beighton Score and right 5th metacarpophalangeal (MCP) joint stress-strain responses), carotid-femoral pulse wave velocity and skin extensibility (percent increase distance two dots with manual traction dorsum right hand) were assessed.

RESULTS

Right 5th MCP stiffness correlated with Beighton Score and with arterial and skin stiffness. High radiographic rate was associated with greater MCP articular (t test p 0.014), arterial (p 0.044) and, in RA <5 years duration, greater skin stiffness (p 0.002) with similar trends in subjects requiring bDMARDs. In RA, arterial stiffness correlated with age (ß p<0.005), articular (ß p<0.001) and skin stiffness (ß p 0.037) and inversely with alcohol consumption (p 0.035).

CONCLUSIONS

Articular, arterial and skin stiffness correlated with each other and with RA severity. As skin is not affected by RA, this association suggests that constitutional stiffness might be a common determinant of RA and CVD. Prospective studies of at-risk preclinical and early RA are required to determine if this relationship is causal.

TRIALS REGISTRATION NUMBER

ACTRN12617000170325.

Genetics, epigenetics and autoimmunity constitute a Bermuda triangle for the pathogenesis of rheumatoid arthritis

Rheumatoid arthritis (RA), a multigene disorder with a heritability rate of 60 %, is characterized by persistent pain, synovial hyperplasia, and cartilage and bone destruction, ultimately causing irreversible joint deformity. The etiology and pathogenesis of rheumatoid arthritis (RA) are primarily influenced by specific genetic variants, particularly HLA alleles such as HLA-DRB1*01 and DRB1*04. However, other HLA alleles such as HLA-DRB1*10 and DPB*1 have also been found to contribute to increased susceptibility to RA. However, non-HLA genes also confer a comparatively high risk of RA disease manifestation. The most relevant single nucleotide polymorphisms (SNPs) associated with non-HLA genes are PTPN22, TRAF1, CXCL-12, TBX-5, STAT4, FCGR, PADI4, and MTHFR. In conjunction with genetic susceptibility, epigenetic alterations orchestrate paramount involvement in regulating RA pathogenesis. Increasing evidence implicates DNA methylation and histone protein modifications, including acetylation and methylation, as the primary epigenetic mechanisms that drive the pathogenesis and clinical progression of the disease. In addition to genetic and epigenetic changes, autoimmune inflammation also determines the pathological progression of the synovial membrane in joints with RA. Glycosylation changes, such as sialylation and fucosylation, in immune cells have been shown to be relevant to disease progression. Genetic heterogeneity, epigenetic factors, and changes in glycosylation do not fully explain the features of RA. Therefore, investigating the interplay between genetics, epigenetics, and autoimmunity is crucial. This review highlights the significance and interaction of these elements in RA pathophysiology, suggesting their diagnostic potential and opening new avenues for novel therapeutic approaches.

From joint pains to hair gains: baricitinib's double duty for rheumatoid arthritis and alopecia areata

Personalised medicine is a key goal across medical specialties today: using biomarkers and knowledge of pathophysiology to ensure the right patients get the right treatment. This becomes more challenging when patients have more than one disease requiring a targeted treatment. Autoimmune diseases commonly co-occur, and thus, multidisciplinary working is important in rheumatology. We present a case where a patient with a new diagnosis of alopecia areata on a background of rheumatoid arthritis was successfully treated with baricitinib monotherapy, with improvement in both conditions.

Unlocking the Future: New Biologic Therapies for Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disorder that leads to joint destruction and functional disability. Traditional treatments, including disease-modifying antirheumatic drugs (DMARDs), often fail, leaving many patients without remission. The advent of biologic therapies that target specific immune system components (e.g., cytokines, T cells) has transformed RA treatment by offering new management options. These biologics (e.g., TNF inhibitors, interleukin blockers) are highly effective in controlling disease activity and preventing joint destruction. However, their use comes with safety concerns, particularly regarding immunosuppression and infection risks. Although still experimental, studies predict that future research will focus on enhancing the clinical response and safety of these agents through personalized approaches or novel mechanisms of action.

Updating on pregnancy in rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA), the most prevalent autoimmune disease in reproductive years, exhibits a higher incidence in females, suggesting involvement of estrogens, genetics and environmental factors in disease onset. Literature shows smaller families in RA patients, driving increased interest in Assisted Reproductive Techniques.

AREAS COVERED

This review elucidates how immunotolerance mechanisms contribute to favorable pregnancy outcomes in RA, emphasizing the need for a careful pregnancy planning to mitigate fetal complications and postnatal flares, which surpass those in the general population. A thorough medication evaluation, orchestrated by a multidisciplinary team, is imperative during pregnancy, weighing potential teratogenic effects against safer alternatives to balance medication safety with disease control. A systematic literature search on PubMed and MEDLINE, using specific terms, covered relevant academic journals up to the latest date.

EXPERT OPINION

This narrative review comprehensively addresses pregnancy-related considerations in RA patients, prioritizing meticulous disease management with pregnancy and breastfeeding-compatible drugs in line with the latest recommendations and registry data. The focus remains on evaluating glucocorticoids, conventional, and biological disease-modifying drugs for compatibility during pregnancy and breastfeeding. Additionally, the evolving landscape of targeted synthetic drugs during pregnancy is explored, providing insights into the latest developments in rheumatological care.

CHIKV infection drives shifts in the gastrointestinal microbiome and metabolites in rhesus monkeys

BACKGROUND

Many studies have demonstrated the association between intestinal microbiota and joint diseases. The "gut-joint axis" also has potential roles in chikungunya virus (CHIKV) infection. Pro-inflammatory arthritis after CHIKV infection might disrupt host homeostasis and lead to dysbacteriosis. This study investigated the characteristics of fecal and gut microbiota, intestinal metabolites, and the changes in gene regulation of intestinal tissues after CHIKV infection using multi-omics analysis to explore the involvement of gut microbiota in the pathogenesis of CHIKV infection.

RESULTS

CHIKV infection increases the systemic burden of inflammation in the GI system of infected animals. Moreover, infection-induced alterations in GI microbiota and metabolites may be indirectly involved in the modulation of GI and bone inflammation after CHIKV infection, including the modulation of inflammasomes and interleukin-17 inflammatory cytokine levels.

CONCLUSION

Our results suggest that the GI tract and its microbes are involved in the modulation of CHIKV infection, which could serve as an indicator for the adjuvant treatment of CHIKV infection. Video Abstract.

Rheumatoid arthritis-associated complications during pregnancy and its effect on offspring: comprehensive review

This study comprehensively explores the complexities of rheumatoid arthritis during pregnancy and its impact on offspring. Through an extensive review of existing literature, we investigate maternal and fetal risks, including adverse pregnancy outcomes and developmental issues in offspring. Utilizing reputable databases such as PubMed, Google Scholar, and Science Direct, we meticulously examined studies exploring the connection between rheumatoid arthritis and pregnancy complications, with a focus on outcomes for offspring. We excluded studies lacking sufficient data or peer review. Synthesizing findings from selected studies, we identified common themes and patterns, presenting results in a clear, organized manner. Our examination reveals a heightened likelihood of preterm birth and preeclampsia among pregnant individuals with rheumatoid arthritis, often correlated with disease activity. Furthermore, we highlight the impact on fetal and neonatal outcomes, such as low birth weight, underscoring the importance of meticulous disease management throughout pregnancy. Balancing the necessity of disease-modifying agents with potential risks, and consideration of medication safety is paramount. A multidisciplinary approach involving rheumatologists and obstetricians is crucial for optimizing outcomes. In conclusion, this synthesis underscores the nuanced challenges of rheumatoid arthritis in pregnancy. A comprehensive understanding and personalized, multidisciplinary approach to an organization is essential for informed decision-making in clinical practice. Our review contributes to ongoing discourse, providing insights for enhanced patient care and guiding future research endeavors.

Cell-Based Therapy and Genome Editing as Emerging Therapeutic Approaches to Treat Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation of the joints. Although much remains unknown about the pathogenesis of RA, there is evidence that impaired immune tolerance and the development of RA are related. And it is precisely the restoration of immune tolerance at the site of the inflammation that is the ultimate goal of the treatment of RA. Over the past few decades, significant progress has been made in the treatment of RA, with higher rates of disease remission and improved long-term outcomes. Unfortunately, despite these successes, the proportion of patients with persistent, difficult-to-treat disease remains high, and the task of improving our understanding of the basic mechanisms of disease development and developing new ways to treat RA remains relevant. This review focuses on describing new treatments for RA, including cell therapies and gene editing technologies that have shown potential in preclinical and early clinical trials. In addition, we discuss the opportunities and limitations associated with the use of these new approaches in the treatment of RA.

Updates on the Pathophysiology and Therapeutic Potential of Extracellular Vesicles with Focus on Exosomes in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an incurable autoimmune disease with high morbidity and socioeconomic burden. Advances in therapeutics have improved patients' quality of life, however due to the complex disease pathophysiology and heterogeneity, 30% of patients do not respond to treatment. Understanding how different genetic and environmental factors contribute to disease initiation and development as well as uncovering the interactions of immune components is key to the implementation of effective and safe therapies. Recently, the role of extracellular vesicles (EVs) in RA development and possible treatment has been an area of interest. EVs are small lipid-bound entities, often containing genetic material, proteins, lipids and amino acids, facilitating paracrine intercellular communication. They are secreted by all cells, and it is believed that they possess regulatory functions due to high complexity and functional diversity. Although it has been shown that EVs participate in RA pathophysiology, through immune modulation, their exact role remains elusive. Furthermore, EVs could be a promising therapeutic agent in various diseases including RA, due to their biocompatibility, low toxicity and possible manipulation, but further research is required in this area. This review provides a comprehensive discussion of disease pathophysiology and summarizes the latest knowledge regarding the role and therapeutic potential of EVs in RA.

Risk Assessment and Optimization for Pregnancy in Patients with Rheumatic Diseases

Patients with rheumatic diseases frequently operate with incomplete or incorrect information while planning for and experiencing pregnancy, often due to variability in provider care and knowledge. Risk assessment at each stage of pregnancy-pre-conception, during pregnancy, and postpartum-is focused on reducing maternal and neonatal complications. This review aims to compile updated, evidence-based guidance on how to minimize risk factors contributing to adverse pregnancy outcomes (APOs). Mitigation of known causes of infertility, appropriate testing and monitoring, achieving low disease activity on pregnancy-safe disease-modifying antirheumatic drugs (DMARDs) prior to conception, controlling hypertension (a frequent comorbidity among patients with certain rheumatic diseases), and the use of appropriate adjunctive medications (such as low-dose aspirin when preeclampsia risk is high) can optimize fertility and prevent adverse maternal and neonatal outcomes.

Therapeutic Potential of Plant-Derived Compounds and Plant Extracts in Rheumatoid Arthritis-Comprehensive Review

Rheumatoid arthritis (RA) is a persistent autoimmune disorder that is characterized by joint inflammation, discomfort, and impairment. Despite the existence of several therapeutic approaches, their effectiveness is often restricted and may be linked to unfavorable side effects. Consequently, there has been growing interest in investigating naturally derived compounds as plausible therapeutic agents for RA disease. The objective of this review is to summarize the existing preclinical and clinical evidence regarding the efficacy of naturally extracted compounds and plant extracts in the treatment of RA, focusing on their anti-inflammatory, anti-oxidative, and immunomodulatory properties. Some of the problems with using natural chemicals are the uneven quality of commercially available preparations and the poor bioavailability of these compounds. Future investigations should focus on improving the formulations, conducting thorough clinical trials, and exploring different techniques to fully utilize the intrinsic potential of naturally derived chemicals in treating RA.

Unveiling the Significance of HLA and KIR Diversity in Underrepresented Populations

Human leukocyte antigen (HLA) molecules and their relationships with natural killer (NK) cells, specifically through their interaction with killer-cell immunoglobulin-like receptors (KIRs), exhibit robust associations with the outcomes of diverse diseases. Moreover, genetic variations in HLA and KIR immune system genes offer limitless depths of complexity. In recent years, a surge of high-powered genome-wide association studies (GWASs) utilizing single nucleotide polymorphism (SNP) arrays has occurred, significantly advancing our understanding of disease pathogenesis. Additionally, advances in HLA reference panels have enabled higher resolution and more reliable imputation, allowing for finer-grained evaluation of the association between sequence variations and disease risk. However, it is essential to note that the majority of these GWASs have focused primarily on populations of Caucasian and Asian origins, neglecting underrepresented populations in Latin America and Africa. This omission not only leads to disparities in health care access but also restricts our knowledge of novel genetic variants involved in disease pathogenesis within these overlooked populations. Since the KIR and HLA haplotypes prevalent in each population are clearly modelled by the specific environment, the aim of this review is to encourage studies investigating HLA/KIR involvement in infection and autoimmune diseases, reproduction, and transplantation in underrepresented populations.

Comprehensive insights into rheumatoid arthritis: Pathophysiology, current therapies and herbal alternatives for effective disease management

Rheumatoid arthritis is a chronic autoimmune inflammatory disease characterized by immune response overexpression, causing pain and swelling in the synovial joints. This condition is caused by auto-reactive antibodies that attack self-antigens due to their incapacity to distinguish between self and foreign molecules. Dysregulated activity within numerous signalling and immunological pathways supports the disease's development and progression, elevating its complexity. While current treatments provide some alleviation, their effectiveness is accompanied by a variety of adverse effects that are inherent in conventional medications. As a result, there is a deep-rooted necessity to investigate alternate therapeutic strategies capable of neutralizing these disadvantages. Medicinal herbs display a variety of potent bioactive phytochemicals that are effective in the complementary management of disease, thus generating an enormous potency for the researchers to delve deep into the development of novel phytomedicine against autoimmune diseases, although additional evidence and understanding are required in terms of their efficacy and pharmacodynamic mechanisms. This literature-based review highlights the dysregulation of immune tolerance in rheumatoid arthritis, analyses the pathophysiology, elucidates relevant signalling pathways involved, evaluates present and future therapy options and underscores the therapeutic attributes of a diverse array of medicinal herbs in addressing this severe disease.

Food-derived bioactive peptides potentiating therapeutic intervention in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that affects the joints of the human body and is projected to have a prevalence age-standardized rate of 1.5 million new cases worldwide by 2030. Several conventional and non-conventional preventive and therapeutic interventions have been suggested but they have their side effects including nausea, abdominal pain, liver damage, ulcers, heightened blood pressure, coagulation, and bleeding. Interestingly, several food-derived peptides (FDPs) from both plant and animal sources are increasingly gaining a reputation for their potential in the management or therapy of RA with little or no side effects. In this review, the concept of inflammation, its major types (acute and chronic), and RA identified as a chronic type were discussed based on its pathogenesis and pathophysiology. The conventional treatment options for RA were briefly outlined as the backdrop of introducing the FDPs that potentiate therapeutic effects in the management of RA.

Gut microbial metabolite targets HDAC3-FOXK1-interferon axis in fibroblast-like synoviocytes to ameliorate rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease. Early studies hold an opinion that gut microbiota is environmentally acquired and associated with RA susceptibility. However, accumulating evidence demonstrates that genetics also shape the gut microbiota. It is known that some strains of inbred laboratory mice are highly susceptible to collagen-induced arthritis (CIA), while the others are resistant to CIA. Here, we show that transplantation of fecal microbiota of CIA-resistant C57BL/6J mice to CIA-susceptible DBA/1J mice confer CIA resistance in DBA/1J mice. C57BL/6J mice and healthy human individuals have enriched B. fragilis than DBA/1J mice and RA patients. Transplantation of B. fragilis prevents CIA in DBA/1J mice. We identify that B. fragilis mainly produces propionate and C57BL/6J mice and healthy human individuals have higher level of propionate. Fibroblast-like synoviocytes (FLSs) in RA are activated to undergo tumor-like transformation. Propionate disrupts HDAC3-FOXK1 interaction to increase acetylation of FOXK1, resulting in reduced FOXK1 stability, blocked interferon signaling and deactivation of RA-FLSs. We treat CIA mice with propionate and show that propionate attenuates CIA. Moreover, a combination of propionate with anti-TNF etanercept synergistically relieves CIA. These results suggest that B. fragilis or propionate could be an alternative or complementary approach to the current therapies.

Different modalities to manage rheumatoid arthritis: an A to Z story

Aim: To investigate different approaches to RA treatment that might lead to greater efficacy and better safety profiles. Methods: The Search strategy was based on medical subject headings, and screening and selection were based on inclusion/exclusion criteria. Results & discussion: Early therapy is critical for disease control and loss of bodily function. The most promising outcomes came from the development of disease-modifying anti-rheumatic drugs. Different foods have anti-inflammatory and antioxidant qualities that protect against the development of rheumatoid arthritis (RA). Some dietary patterns and supplements have been shown to have potential protective benefits against RA. Conclusion: Improvement in the quality of life of RA patients requires a tailored management approach based on the current patient medical data.

Associations of per- and polyfluoroalkyl substances (PFAS) and their mixture with risk of rheumatoid arthritis in the U.S. adult population

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are known environmental contaminants with immunosuppressive properties. Their connection to rheumatoid arthritis (RA), a condition influenced by the immune system, is not well studied. This research explores the association between PFAS exposure and RA prevalence.

METHODS

This research utilized data from the NHANES, encompassing a sample of 10,496 adults from the 2003-2018 cycles, focusing on serum levels of several PFAS. The presence of RA was determined based on self-reports. This study used multivariable logistic regression to assess the relationship between individual PFAS and RA risk, adjusting for covariates to calculate odds ratios (ORs). The combined effects of PFAS mixtures were evaluated using BKMR, WQS regression, and quantile g-computation. Additionally, sex-specific associations were explored through stratified analysis.

RESULTS

Higher serum PFOA (OR = 0.88, 95% CI: 0.79, 0.98), PFHxS (OR = 0.91, 95% CI: 0.83, 1.00), PFNA (OR = 0.87, 95% CI: 0.77, 0.98), and PFDA (OR = 0.89, 95% CI: 0.81, 0.99) concentration was related to lower odds of RA. Sex-specific analysis in single chemical models indicated the significant inverse associations were only evident in females. BKMR did not show an obvious pattern of RA estimates across PFAS mixture. The outcomes of sex-stratified quantile g-computation demonstrated that an increase in PFAS mixture was associated with a decreased odds of RA in females (OR: 0.76, 95% CI: 0.62, 0.92). We identified a significant interaction term of the WQS*sex in the 100 repeated hold out WQS analysis. Notably, a higher concentration of the PFAS mixture was significantly associated with reduced odds of RA in females (mean OR = 0.93, 95% CI: 0.88, 0.98).

CONCLUSIONS

This study indicates potential sex-specific associations of exposure to various individual PFAS and their mixtures with RA. Notably, the observed inverse relationships were statistically significant in females but not in males. These findings contribute to the growing body of evidence indicating that PFAS may have immunosuppressive effects.

Shared genetic architecture between hypothyroidism and rheumatoid arthritis: A large-scale cross-trait analysis

BACKGROUND

In recent years, mounting evidence has indicated a co-morbid relationship between hypothyroidism and rheumatoid arthritis (RA), however, the shared genetic factors underlying this association remain unclear. This study aims to investigate the common genetic architecture between hypothyroidism and RA.

METHODS

Genome-wide association study (GWAS) summary statistics from recently published studies were utilized to examine the genetic correlation, shared genetic loci, and potential causal relationship between hypothyroidism and RA. Statistical methods included linkage disequilibrium score regression (LDSC), high-definition likelihood (HDL), cross-trait meta-analyses, colocalization analysis, multi-marker analysis of genomic annotation (MAGMA), tissue-specific enrichment analysis (TSEA), functional enrichment analysis, and latent causal variable method (LCV).

RESULTS

Our study demonstrated a significant genetic correlation between hypothyroidism and RA(LDSC:rg=0.3803,p=7.23e-11;HDL:rg=0.3849,p=1.02e-21). Through cross-trait meta-analysis, we identified 1035 loci, including 43 novel genetic loci. By integrating colocalization analysis and the MAGMA algorithm, we found a substantial number of genes, such as PTPN22, TYK2, and CTLA-4, shared between the two diseases, which showed significant enrichment across 14 tissues. These genes were primarily associated with the regulation of alpha-beta T cell proliferation, positive regulation of T cell activation, positive regulation of leukocyte cell-cell adhesion, T cell receptor signaling pathway, and JAK-STAT signaling pathway. However, our study did not reveal a significant causal association between the two diseases using the LCV approach.

CONCLUSION

Based on these findings, there is a significant genetic correlation between hypothyroidism and RA, suggesting a shared genetic basis for these conditions.

Quadricuspid Aortic Valve and Rheumatoid Arthritis: A Coincidence or Interconnection

Quadricuspid aortic valve is a very rare congenital anomaly. Its association with rheumatoid arthritis is exceptional with this being the third case reported in the literature. We report a case of a 52 year old female patient with quadricuspid aortic valve type C accompanied by moderate to severe aortic regurgitation and longstanding, advanced form of rheumatoid arthritis. Having refused surgical aortic valve intervention 4 years ago, the patient is currently under a watchful follow-up strategy. The patient received a diagnosis of rheumatoid arthritis over 15 years before and presently has serious deformities in the hands, legs, feet, and spine. In conclusion, quadricuspid aortic valve and rheumatoid arthritis together are extremely rare. While it is possible that this association is coincidental, considering the genetic background of both disorders, there is a potential for them to be interconnected comorbidities. This report is the first to highlight the association between the 2 disorders.

Identification and Verification of Novel Biomarkers Involving Rheumatoid Arthritis with Multimachine Learning Algorithms: An In Silicon and In Vivo Study

Background

Rheumatoid arthritis (RA) remains one of the most prevalent chronic joint diseases. However, due to the heterogeneity among RA patients, there are still no robust diagnostic and therapeutic biomarkers for the diagnosis and treatment of RA.

Methods

We retrieved RA-related and pan-cancer information datasets from the Gene Expression Omnibus and The Cancer Genome Atlas databases, respectively. Six gene expression profiles and corresponding clinical information of GSE12021, GSE29746, GSE55235, GSE55457, GSE77298, and GSE89408 were adopted to perform differential expression gene analysis, enrichment, and immune component difference analyses of RA. Four machine learning algorithms, including LASSO, RF, XGBoost, and SVM, were used to identify RA-related biomarkers. Unsupervised cluster analysis was also used to decipher the heterogeneity of RA. A four-signature-based nomogram was constructed and verified to specifically diagnose RA and osteoarthritis (OA) from normal tissues. Consequently, RA-HFLS cell was utilized to investigate the biological role of CRTAM in RA. In addition, comparisons of diagnostic efficacy and biological roles among CRTAM and other classic biomarkers of RA were also performed.

Results

Immune and stromal components were highly enriched in RA. Chemokine- and Th cell-related signatures were significantly activated in RA tissues. Four promising and novel biomarkers, including CRTAM, PTTG1IP, ITGB2, and MMP13, were identified and verified, which could be treated as novel treatment and diagnostic targets for RA. Nomograms based on the four signatures might aid in distinguishing and diagnosing RA, which reached a satisfactory performance in both training (AUC = 0.894) and testing (AUC = 0.843) cohorts. Two distinct subtypes of RA patients were identified, which further verified that these four signatures might be involved in the immune infiltration process. Furthermore, knockdown of CRTAM could significantly suppress the proliferation and invasion ability of RA cell line and thus could be treated as a novel therapeutic target. CRTAM owned a great diagnostic performance for RA than previous biomarkers including MMP3, S100A8, S100A9, IL6, COMP, LAG3, and ENTPD1. Mechanically, CRTAM could also be involved in the progression through immune dysfunction, fatty acid metabolism, and genomic instability across several cancer subtypes.

Conclusion

CRTAM, PTTG1IP, ITGB2, and MMP13 were highly expressed in RA tissues and might function as pivotal diagnostic and treatment targets by deteriorating the immune dysfunction state. In addition, CRTAM might fuel cancer progression through immune signals, especially among RA patients.

The causal impact of saturated fatty acids on rheumatoid arthritis: a bidirectional Mendelian randomisation study

Objective

The causal relationship between saturated fatty acids (SFAs) and rheumatoid arthritis (RA) remains poorly understood. This study aimed to determine whether SFAs are causally related to RA using Mendelian randomisation (MR) analyses.

Methods

Genome-wide association study (GWAS) summary data for RA (ukb-d-M13_RHEUMA) and SFAs (met-d-SFA) were obtained from the Integrative Epidemiology Unit OpenGWAS database. A bidirectional MR analysis was performed using a suite of algorithms, namely the MR-Egger, weighted median, simple mode, weighted mode, and inverse-variance weighted (IVW) algorithms, all integrated using the "MR" function. The robustness of the MR findings was further evaluated through sensitivity analyses, including heterogeneity, horizontal pleiotropy, and leave-one-out tests.

Results

The IVW algorithm in the forward MR analysis indicated a causal link between SFAs and RA (p = 0.025), identifying SFAs as a risk factor for RA (odds ratio = 1.001). Sensitivity analyses indicated no significant heterogeneity, horizontal pleiotropy, or severe bias, reinforcing the credibility of the forward MR results. However, the reverse MR analysis revealed that RA does not causally affect SFA levels (p = 0.195), and this finding was supported by corresponding sensitivity analyses.

Conclusion

The findings of this study substantiate the positive causal effect of SFAs on the incidence of RA through bidirectional MR analysis, thereby offering a consequential direction for future research on the diagnosis and treatment of RA.

Interleukin-18 Gene Polymorphisms and Rheumatoid Arthritis Susceptibility: An Umbrella Review of Meta-Analyses

This study systematically analyzes the association between interleukin-18 (IL-18) gene polymorphisms and rheumatoid arthritis (RA) susceptibility. The electronic databases Ovid MEDLINE, Ovid Excerpta Medica Database, and Cochrane Library were searched to identify meta-analyses that included case-control studies reporting IL-18 gene polymorphisms and RA susceptibility. Data were reanalyzed using Review Manager Software 5.1, and Mantel-Haenszel random effects were applied for the five genetic models: allelic, recessive, dominant, homozygote, and heterozygote. The effect size of odds ratios (ORs) and their corresponding 95% confidence interval (CI) were calculated. A total of seven meta-analyses with poor quality were included. The IL-18 polymorphisms -607 A/C, -137 C/G, -920 T/C, and -105 C/A have been reported. With weak evidence, IL-18 -607 A/C polymorphisms were associated with a reduced risk of RA susceptibility using the allele model (OR = 0.76, 95% CI: 0.61 - 0.93, p=0.01), dominant model (OR = 0.67, 95% CI: 0.50 - 0.90, p=0.008), homozygote model (OR = 0.57, 95% CI: 0.35 - 0.91, p=0.02), and heterozygote model (OR = 0.71, 95% CI: 0.54 - 0.93, p=0.01) in the overall population. IL-18 gene polymorphisms and RA susceptibility are affected by ethnicity: With weak evidence, IL-18 -137 C/G polymorphisms were related to reduce RA susceptibility in the Asian population (allele model: OR = 0.59, 95% CI: 0.40 - 0.88, p=0.01; dominant model: OR = 0.57, 95% CI: 0.37 - 0.89, p=0.01; heterozygote model: OR = 0.60, 95% CI: 0.38 - 0.94, p=0.03). IL-18 -607 A/C gene polymorphisms are a protective factor for RA susceptibility in the overall population, and IL-18 -137 C/G gene polymorphisms are a protective factor for RA susceptibility in the Asian population. Further studies are needed to confirm these results owing to the limitations of the included studies.

Screening of the key response component groups and mechanism verification of Huangqi-Guizhi-Wuwu-Decoction in treating rheumatoid arthritis based on a novel computational pharmacological model

BACKGROUND

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by the destruction of synovial tissue and articular cartilage. Huangqi-Guizhi-Wuwu-Decoction (HGWD), a formula of Traditional Chinese Medicine (TCM), has shown promising clinical efficacy in the treatment of RA. However, the synergistic effects of key response components group (KRCG) in the treatment of RA have not been well studied.

METHODS

The components and potential targets of HGWD were extracted from published databases. A novel node influence calculation model that considers both the node control force and node bridging force was designed to construct the core response space (CRS) and obtain key effector proteins. An increasing coverage coefficient (ICC) model was employed to select the KRCG. The effectiveness and potential mechanism of action of KRCG were confirmed using CCK-8, qPCR, and western blotting.

RESULTS

A total of 796 key effector proteins were identified in CRS. The Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses confirmed their effectiveness and reliability. In addition, 59 components were defined as KRCG, which contributed to 85.05% of the target coverage of effective proteins. Of these, 677 targets were considered key reaction proteins, and their enriched KEGG pathways accounted for 84.89% of the pathogenic genes and 87.94% of the target genes. Finally, four components (moupinamide, 6-Paradol, hydrocinnamic acid, and protocatechuic acid) were shown to inhibit the inflammatory response in RA by synergistically targeting the cAMP, PI3K-Akt, and HIF-1α pathways.

CONCLUSIONS

We have introduced a novel model that aims to optimize and analyze the mechanisms behind herbal formulas. The model revealed the KRCG of HGWD for the treatment of RA and proposed that KRCG inhibits the inflammatory response by synergistically targeting cAMP, PI3K-Akt, and HIF-1α pathways. Overall, the novel model is plausible and reliable, offering a valuable reference for the secondary development of herbal formulas.

Human DNA Mutations and their Impact on Genetic Disorders

DNA is a remarkably precise medium for copying and storing biological information. It serves as a design for cellular machinery that permits cells, organs, and even whole organisms to work. The fidelity of DNA replication results from the action of hundreds of genes involved in proofreading and damage repair. All human cells can acquire genetic changes in their DNA all over life. Genetic mutations are changes to the DNA sequence that happen during cell division when the cells make copies of themselves. Mutations in the DNA can cause genetic illnesses such as cancer, or they could help humans better adapt to their environment over time. The endogenous reactive metabolites, therapeutic medicines, and an excess of environmental mutagens, such as UV rays all continuously damage DNA, compromising its integrity. One or more chromosomal alterations and point mutations at a single site (monogenic mutation) including deletions, duplications, and inversions illustrate such DNA mutations. Genetic conditions can occur when an altered gene is inherited from parents, which increases the risk of developing that particular condition, or some gene alterations can happen randomly. Moreover, symptoms of genetic conditions depend on which gene has a mutation. There are many different diseases and conditions caused by mutations. Some of the most common genetic conditions are Alzheimer's disease, some cancers, cystic fibrosis, Down syndrome, and sickle cell disease. Interestingly, scientists find that DNA mutations are more common than formerly thought. This review outlines the main DNA mutations that occur along the human genome and their influence on human health. The subject of patents pertaining to DNA mutations and genetic disorders has been brought up.

Pharmacological targets at the lysosomal autophagy-NLRP3 inflammasome crossroads

Many aspects of cell homeostasis and integrity are maintained by the nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome. The NLRP3 oligomeric protein complex assembles in response to exogenous and endogenous danger signals. This inflammasome has also been implicated in the pathogenesis of a range of disease conditions, particularly chronic inflammatory diseases. Given that NLRP3 modulates autophagy, which is also a key regulator of inflammasome activity, excessive inflammation may be controlled by targeting this intersecting pathway. However, specific niche areas of NLRP3-autophagy interactions and their reciprocal regulatory mechanisms remain underexplored. Consequently, we lack treatment methods specifically targeting this pivotal axis. Here, we discuss the potential of such strategies in the context of autoimmune and metabolic diseases and propose some research avenues.

The Clinical Promise of Microalgae in Rheumatoid Arthritis: From Natural Compounds to Recombinant Therapeutics

Rheumatoid arthritis (RA) is an invalidating chronic autoimmune disorder characterized by joint inflammation and progressive bone damage. Dietary intervention is an important component in the treatment of RA to mitigate oxidative stress, a major pathogenic driver of the disease. Alongside traditional sources of antioxidants, microalgae-a diverse group of photosynthetic prokaryotes and eukaryotes-are emerging as anti-inflammatory and immunomodulatory food supplements. Several species accumulate therapeutic metabolites-mainly lipids and pigments-which interfere in the pro-inflammatory pathways involved in RA and other chronic inflammatory conditions. The advancement of the clinical uses of microalgae requires the continuous exploration of phytoplankton biodiversity and chemodiversity, followed by the domestication of wild strains into reliable producers of said metabolites. In addition, the tractability of microalgal genomes offers unprecedented possibilities to establish photosynthetic microbes as light-driven biofactories of heterologous immunotherapeutics. Here, we review the evidence-based anti-inflammatory mechanisms of microalgal metabolites and provide a detailed coverage of the genetic engineering strategies to enhance the yields of endogenous compounds and to develop innovative bioproducts.

Identification of shared disease marker genes and underlying mechanisms between major depression and rheumatoid arthritis

Both depression and rheumatoid arthritis (RA) have a very high comorbidity rate. A bilateral association is estimated to increase the mutual risk and the common denominator is inflammation being observed in both diseases. Previous studies have mainly focused on assessing peripheral blood's inflammatory and pro-inflammatory cytokines levels. We aimed to extend insights into the molecular mechanisms of depression based on hub RA genes. To do so, we prioritized RA-related genes using in-silico tools. We then investigated whether RA-related genes undergo altered expression in patients with unipolar and bipolar depression without a concurrent RA diagnosis and any exponents of active inflammation. In addition, we selected a homogeneous group of patients treated with lithium (Li), which has immunomodulatory properties. The study was performed on patients with bipolar depression (BD, n = 45; Li, n = 20), unipolar depression (UD, n = 27), and healthy controls (HC, n = 22) of both sexes. To identify DEGs in peripheral blood mononuclear cells (PBMCs), we used the SurePrint G3 Microarray and GeneSpring software. We selected a list of 180 hub genes whose altered expression we analyzed using the expression microarray results. In the entire study group, we identified altered expression of 93 of the 180 genes, including 35 down-regulated (OPRM1 gene with highest FC > 3) and 58 up-regulated (TLR4 gene with highest FC > 3). In UD patients, we observed maximally up-regulated expression of the TEK gene (FC > 3), and in BD of the CXCL8 gene (FC > 5). On the other hand, in lithium-treated patients, the gene with the most reduced expression was the TRPV1 gene. The study proved that depression and RA are produced by a partially shared "inflammatory interactome" in which the opioid and angiogenesis pathways are important.

The effect of HLA-DRB1*04:01 on a mouse model of atherosclerosis

Objectives

HLA-DRB1 is associated with an increased risk of cardiovascular disease in patients with rheumatoid arthritis (RA). This study aimed to determine the effect of HLA-DRB1 on atherosclerotic cardiovascular disease (ASCVD) using a novel mouse model.

Methods

Mice transgenic for HLA-DRB1*04:01 (DR4tg) were crossed with low density lipoprotein receptor knock-out (Ldlr^-/-) mice that develop atherosclerosis when fed a high fat, high cholesterol (HFHC) diet. Male and female DR4tgLdlr^-/- (n = 48), Ldlr^-/- (n = 24), DR4tg (n = 24), and C57Bl/6 (B6) background (n = 24) mice were fed HFHC or regular diet (RD) for 12 weeks. Blood samples were analyzed for serum lipoproteins using a colorimetric assay. C-reactive protein (CRP) and oxidized LDL (OxLDL) were measured using ELISA. Atherosclerosis in the aortas was assessed using the lipid stain, Sudan IV. The presence of citrulline in atherosclerotic plaque was determined by immunohistochemistry.

Results

Sera low-density lipoprotein cholesterol (LDL-C) levels were higher in HFHC-fed Ldlr^-/- versus DR4tgLdlr^-/--; p = 0.0056, but the aortic plaque burden and degree of citrullination in the plaque were similar for these two strains. The ratio of pro-atherogenic OxLDL to LDL levels was higher in DR4tgLdlr^-/- than Ldlr^-/-mice; p = 0.0017. All mice had an increase in CRP when fed a HFHC diet, most pronounced for DR4tgLdlr^-/-; p = 0.0009. There were no significant sex differences for DR4tgLdlr^-/- mice; however, male Ldlr^-/- mice had worse atherosclerosis. B6 and DR4tg mice did not have significant elevations in serum cholesterol levels and did not develop atherosclerosis.

Conclusions

Expression of HLA-DRB1 resulted in an elevation of OxLDL and a reduction in the male bias for atherosclerosis, mimicking what is observed in RA.

An AI Approach to Identifying Novel Therapeutics for Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disorder that has a significant impact on quality of life and work capacity. Treatment of RA aims to control inflammation and alleviate pain; however, achieving remission with minimal toxicity is frequently not possible with the current suite of drugs. This review aims to summarise current treatment practices and highlight the urgent need for alternative pharmacogenomic approaches for novel drug discovery. These approaches can elucidate new relationships between drugs, genes, and diseases to identify additional effective and safe therapeutic options. This review discusses how computational approaches such as connectivity mapping offer the ability to repurpose FDA-approved drugs beyond their original treatment indication. This review also explores the concept of drug sensitisation to predict co-prescribed drugs with synergistic effects that produce enhanced anti-disease efficacy by involving multiple disease pathways. Challenges of this computational approach are discussed, including the availability of suitable high-quality datasets for comprehensive analysis and other data curation issues. The potential benefits include accelerated identification of novel drug combinations and the ability to trial and implement established treatments in a new index disease. This review underlines the huge opportunity to incorporate disease-related data and drug-related data to develop methods and algorithms that have strong potential to determine novel and effective treatment regimens.

Rheumatoid arthritis increases the risk of malignant neoplasm of bone and articular cartilage: a two-sample bidirectional mendelian randomization study

OBJECTIVE

Prior research has revealed a heightened prevalence of neoplasms in individuals diagnosed with rheumatoid arthritis (RA). The primary objective of this study is to delve into the causal association between RA and two distinct types of neoplasms: benign neoplasm of bone and articular cartilage (BNBAC) and malignant neoplasm of bone and articular cartilage (MNBAC).

METHODS

We employed summary data from genome-wide association analyses (GWAS) to investigate the causal relationship between RA and two neoplasms, BNBAC and MNBAC, using a two-sample bidirectional Mendelian randomization (MR) study design. The IEU OpenGWAS database provided the GWAS summary data for RA, while the Finnish consortium supplied the GWAS summary data for BNBAC and MNBAC. Our analysis involved the utilization of eight distinct MR methods, namely random-effects inverse variance weighted (IVW), MR Egger, weighted median, simple mode, weighted mode, maximum likelihood, penalized weighted median, and fixed effects IVW. Subsequently, we conducted assessments to evaluate heterogeneity, horizontal pleiotropy, outliers, the impact of a single-nucleotide polymorphism (SNP), and adherence to the assumption of normal distribution in the MR analysis.

RESULTS

The results from the MR analysis revealed that there was no significant genetic association between RA and BNBAC (P = 0.427, odds ratio [OR] 95% confidence interval [CI] = 0.971 [0.904-1.044]). However, a positive genetic association was observed between RA and MNBAC (P = 0.001, OR 95% CI = 1.413 [1.144-1.745]). Conducting a reverse MR analysis, we found no evidence to support a genetic causality between BNBAC (P = 0.088, OR 95% CI = 1.041 [0.994-1.091]) or MNBAC (P = 0.168, OR 95% CI = 1.013 [0.995-1.031]) and RA. Our MR analysis demonstrated the absence of heterogeneity, horizontal pleiotropy, and outliers and confirmed that the effect was not driven by a single SNP. Additionally, the data exhibited a normal distribution.

CONCLUSION

The findings of this study demonstrate that RA constitutes a significant risk factor for MNBAC. In the context of clinical application, it is advisable to conduct MNBAC screening in RA patients and remain vigilant regarding its potential manifestation. Importantly, the outcomes of this investigation introduce a fresh vantage point into the understanding of the tumorigenesis associated with RA.

Association between PYTPN22 rs2476601, VEGF rs833070, TNFAIP3 rs6920220 Polymorphisms and Risk for Rheumatoid Arthritis in Early Undifferentiated Arthritis Patients: A Pilot Study

Background and Objectives: About 40% of early undifferentiated arthritis (UA) progresses to rheumatoid (RA) or other chronic arthritis. Novel diagnostic tools predicting the risk for this progression are needed to identify the patients who would benefit from early aggressive treatment. Evidence on the role of single-nucleotide polymorphisms (SNPs) in the development of RA has emerged. The aim of our study was to investigate the association between rs2476601, rs833070, and rs6920220 SNPs and UA progression to RA. Materials and Methods: Ninety-two UA patients were observed for 12 months. At study entry, demographic and clinical characteristics were recorded, musculoskeletal ultrasonography was performed, and blood samples were drawn to investigate levels of inflammatory markers, rheumatoid factor (RF), anti-citrullinated protein antibodies (anti-CCP)detect SNPs. After 12 months, UA outcomes were assessed, and patients were divided into two (RA and non-RA) groups. The association between the risk of progression to chronic inflammatory arthritis and analyzed SNPs was measured by computing odds ratios (OR). Results: After a 12-month follow-up, 27 (29.3%) patients developed RA, and 65 (70.7%) patients were assigned to the non-RA group. The arthritis of 21 patients (22.8%) from the non-RA group resolved completely, while the other 44 (47.2%) patients were diagnosed with another rheumatic inflammatory disease. The patients who developed RA had a significantly greater number of tender and swollen joints (p = 0.010 and p = 0.021 respectively) and were more frequently RF or anti-CCP (p < 0.001), and both RF and anti-CCP positive (p < 0.001) at the baseline as compared with the patients in the non-RA group. No significant association between rs2476601 (OR = 0.99, p = 0.98), rs833070 (OR = 1.0, p = 0.97), and rs6920220 (OR = 0.48, p = 0.13) polymorphisms and the risk of developing RA were found. Conclusions: No association between analyzed SNPs and a greater risk to progress from UA to RA was confirmed, although patients with rs6920220 AA + AG genotypes had fewer tender joints at the disease onset.

Unexpected High Need for Genetic Testing in Rheumatology: A Cross-Sectional Cohort Study

BACKGROUND

Genetic testing may provide information for diagnostic, prognostic and pharmacogenetic purposes. The PREPARE study recently showed that the number of clinically relevant adverse drug reactions could be reduced via genotype-guided treatment. The aim of this work was to assess the relevance of genetic testing and its actual use in consecutive rheumatic outpatients.

METHODS

A retrospective cross-sectional analysis was performed with data from a prospectively designed observational project with outpatients consecutively recruited from a university clinic of rheumatology.

RESULTS

In this cohort of 2490 patients, the potential need for genetic testing is immense, with 57.3% of patients having the potential to benefit from genetic testing according to their diagnosis and treatment and 53.3% of patients with actually performed genetic testing for diagnostic, prognostic or pharmacogenetic purposes. In detail, patients would potentially benefit from genetic testing especially for therapeutic (28.0%) and diagnostic (26.9%) purposes. Genetic testing was performed for diagnostic purposes in 51.6% of subjects, for pharmacogenetic purposes in 3.7% and for prognostic purposes in 0.1%. The ratio between the number of patients who had had tests performed to those with a potential need for genetic testing decreased with age, from 127.1% for 20 to <30-year-old patients to 46.1% for 80 to <90-year-old patients. Pharmacogenetic testing was only performed for disease-related medications.

CONCLUSIONS

Genetic testing is frequently needed in patients with rheumatic diseases. The value of pharmacogenetic testing is certainly underestimated, especially in case of medications for comorbidities.

Paroxysmal Nocturnal Hemoglobinuria: Biology and Treatment

Paroxysmal nocturnal hemoglobinuria (PNH) is a nonmalignant clonal hematopoietic disorder characterized by the lack of glycosylphosphatidylinositol-anchored proteins (GPI-APs) as a consequence of somatic mutations in the phosphatidylinositol glycan anchor biosynthesis class A (PIGA) gene. Clinical manifestations of PNH are intravascular hemolysis, thrombophilia, and bone marrow failure. Treatment of PNH mainly relies on the use of complement-targeted therapy (C5 inhibitors), with the newest agents being explored against other factors involved in the complement cascade to alleviate unresolved intravascular hemolysis and extravascular hemolysis. This review summarizes the biology and current treatment strategies for PNH with the aim of reaching a general audience with an interest in hematologic disorders.

Effects of Human Leukocyte Antigen DRB1 Genetic Polymorphism on Anti-Cyclic Citrullinated Peptide (ANTI-CCP) and Rheumatoid Factor (RF) Expression in Rheumatoid Arthritis (RA) Patients

Rheumatoid arthritis (RA) is a systemic disease characterized by non-infectious inflammation of the joints and surrounding tissues, which can cause severe health problems, affect the patient's daily life, and even cause death. RA can be clinically diagnosed by the occurrence of blood serological markers, rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody (anti-CCP). However, about 20% of RA patients exhibit negative results for both markers, which makes RA diagnosis difficult and, therefore, may delay the effective treatment. Previous studies found some evidence that human leukocyte antigen (HLA)-related genes might be the susceptibility genes for RA and their polymorphisms might contribute to varieties of susceptibility and disease severity. This study aimed for the genetic polymorphisms of the RA patient genome and their effects on the RA patient's serological makers, RF and anti-CCP. A total of 4580 patients' electronic medical records from 1992 to 2020 were retrieved from the China Medical University Hospital database. The most representative single-nucleotide polymorphisms (SNPs) were identified through a genome-wide association study (GWAS) followed by enzyme-linked immunosorbent assay (ELISA) validation using the blood from 30 additional RA patients. The results showed significant changes at the position of chromosome 6 with rs9270481 being the most significant locus, which indicated the location of the HLA-DRB1 gene. Further, patients with the CC genotype at this locus were more likely to exhibit negative results for RF and anti-CCP than those with the TT genotype. The C allele was also more likely to be associated with negative results for RF and anti-CCP. The results demonstrated that a genetic polymorphism at rs9270481 affected the expression of RF and anti-CCP in RA patients, which might indicate the necessity to develop a personalized treatment plan for each individual patient based on the genetic profile.