Genetics of rheumatoid arthritis susceptibility, severity, and treatment response

Protective effect of a combination of multiple strains of Lactobacillus acidophilus on collagen-induced arthritis

Rheumatoid arthritis (RA) is a systemic, chronic autoimmune disease. Many studies have shown that microorganisms may be an important pathological factor leading to the onset of RA. Some infectious or non-infectious pathogenic microorganisms and their metabolites may be the initiating factors of the early onset of RA. The aim of this study was to alleviate RA by regulating the imbalance of the gut microbiota in the early stage of RA using mixed bacterial strains. The mixed strains of Lactobacillus acidophilus (BD18, NCFM, BD1802, BD3545, BD5032) significantly reduced the clinical score and swelling thickness of the paws of collagen-induced arthritis (CIA) rats. The expression of TNF-α and MMP-13 proteins in the joints of CIA rats was also inhibited. The levels of specific antibodies (anti-CII IgG, anti-CII IgG1, anti-CII IgG2a, and anti-CII IgG2b) and inflammatory factor IL-6 in the serum of CIA rats were also significantly reduced. The relative abundance of Lactobacillus, Clostridia_UCG-014, Ruminococcus, Candidatus_Saccharimonas, Romboutsia, Turicibacter, and Clostridium_sensu_stricto_1 in the gut microbiota of CIA rats receiving oral administration of the mixed strains of L. acidophilus was significantly reduced, bringing their microbiota closer to that of healthy rats. Moreover, the levels of intestinal metabolites of short chain fatty acids in CIA rats, acetic acid and butyric acid, were significantly increased. The mixed strains of L. acidophilus could recover the relative abundance of Ligilactobacillus, Clostridia_UCG-014_unclassified, Ruminococcus, Candidatus_Saccharimonas, Romboutsia and Turicibacter, affecting purine metabolism, transcription factors and alanine metabolism, and reducing the levels of specific antibodies and inflammatory factors in the blood, finally slowing the development of experimental arthritis induced by CII, which exerts the protective effect of probiotics. Mixed L. acidophilus strains are more effective than a single strain, and the effect is not the result of a single strain, but of a combination of strains.

Identifying the genetic association between rheumatoid arthritis and the risk of pulmonary arterial hypertension

Epidemiological and observational studies have indicated an association between rheumatoid arthritis (RA) and pulmonary arterial hypertension (PAH). However, consistent conclusions have not been reached due to various limitations. In order to determine whether RA and PAH are causally related, we conducted a Mendelian randomization (MR) study with two samples. Data for overall RA (13,621 cases and 262,844 controls), seropositive RA (5103 cases and 402,554 controls), seronegative RA (4192 cases and 311,210 controls), and PAH (248 cases and 289,117 controls) derived from the FinnGen consortium. The inverse variance weighted, along with four other effective methodologies, were employed to comprehensively infer the causal relationships between RA and PAH. To assess the estimation's robustness, a number of sensitivity studies were performed. Causal genetic association was found between seropositive RA and decreased risk of PAH (odds ratio (OR) = 0.812, 95% confidence interval (CI) = 0.687-0.959, p = 0.042), while no causal relationship was found between overall RA or seronegative RA and PAH (OR = 0.871, 95% CI = 0.645-1.175, p = 0.548; OR = 0.791, 95%CI = 0.471-1.328, p = 0.374, respectively). We are the first to use MR analysis to explore the causal relationship between RA and PAH, revealing a decreased risk of PAH in individuals with seropositive RA. Key Points • There is a notable genetic association between seropositive RA and a decreased risk of developing PAH. • No significant association was observed between overall RA or seronegative RA and the risk of PAH. • RA represents a heterogeneous disease, with its seropositive or seronegative forms exhibiting distinct genetic characteristics.

Genetics of rheumatoid arthritis

In the past four decades, a plethora of genetic association studies have been carried out in cohorts of patients with rheumatoid arthritis. These studies have highlighted key aspects of disease pathogenesis and suggested causal mechanisms. In this review, we discuss major advances in our understanding of the genetic architecture of rheumatoid arthritis susceptibility, severity and treatment response and explain how genetics supports current models of disease pathogenesis and outcome. We outline future research directions, like Mendelian randomisation, and present a number of potential avenues for clinical translation, including risk and outcome prediction, patient stratification into treatment response groups and pharmacological applications.

IL33-induced neutrophil extracellular traps (NETs) mediate a positive feedback loop for synovial inflammation and NET amplification in rheumatoid arthritis

This study investigated the mechanisms driving the induction and sustained presence of neutrophil extracellular traps (NETs) in the synovial microenvironment of rheumatoid arthritis (RA). Synovial tissue and fluid samples were collected from patients with RA and osteoarthritis (OA), and NET levels and cytokine concentrations were measured using a cytometric bead array and enzyme-linked immunosorbent assay (ELISA). The ability of interleukin-33 (IL-33) to induce NET formation was evaluated using quantitative assays, immunofluorescence staining, live-cell imaging, and electron microscopy. Coincubation experiments of NETs with fibroblast-like synovial cells (FLSs) were conducted, and a modified Transwell migration assay was designed to assess neutrophil migration. The role of IL-33 and NETs in RA progression was further investigated using a collagen antibody-induced arthritis (CAIA) mouse model. The results revealed an increase in NETs and IL-33 levels in the synovial fluid of RA patients, with a significant positive correlation between them. NET formation assays confirmed that IL-33 activates neutrophils to produce NETs and that neutrophils from RA patients exhibit increased responsiveness to IL-33 stimulation. Both in vitro and in vivo evidence has demonstrated that NETs stimulate FLSs to secrete IL-33 and the chemokine CXCL8 via Toll-like receptor 9, promoting further neutrophil recruitment and increasing NET production within the RA synovium. This study reveals a novel positive feedback loop involving NETs and FLSs that is mediated by IL-33 that increases NET accumulation in RA. Targeting IL-33 or NET formation and amplification may offer new therapeutic strategies for managing RA.

Applications of single-cell RNA sequencing in rheumatoid arthritis

Single cell RNA sequencing (scRNA-seq) is a relatively new technology that provides an unprecedented, detailed view of cellular heterogeneity and function by delineating the transcriptomic difference among individual cells. This will allow for mapping of cell-type-specific signaling during physiological and pathological processes, to build highly specific models of cellular signaling networks between the many discrete clusters that are present. This technology therefore provides a powerful approach to dissecting the cellular and molecular mechanisms that contribute to autoimmune diseases, including rheumatoid arthritis (RA). scRNA-seq can offer valuable insights into RA unique cellular states and transitions, potentially enabling development of novel drug targets. However, some challenges that still limit its mainstream utilization and include higher costs, a lower sensitivity for low-abundance transcripts, and a relatively complex data analysis workflow relative to bulk or traditional RNA-seq. This minireview explores the emerging application of scRNA-seq in RA research, highlighting its role in producing important insights that can help pave the way for innovative and more effective therapeutic strategies.

Abatacept retention and clinical effectiveness in patients with rheumatoid arthritis in a real-world setting in Taiwan

AIM

To evaluate real-world abatacept retention and clinical outcomes in patients with rheumatoid arthritis in Taiwan.

METHODS

This prospective, observational study enrolled patients with rheumatoid arthritis aged ≥20 years who received abatacept in real-world practice. The primary endpoint was the abatacept retention rate at 24 months. Patients were categorized into subgroups based on abatacept treatment status and previous biological disease-modifying antirheumatic drug (bDMARD) therapy. Risk factors affecting abatacept retention were determined by regression analysis.

RESULTS

A total of 212 patients were enrolled. The overall abatacept retention rate at 24 months among all patients was 59.9% (95% confidence interval 53.0%-66.6%). Patients who were ongoing users of abatacept and bDMARD-naïve had the highest retention rate (76.3%); of these, 31.6% achieved low disease activity or remission after 2 years. Previous treatment with bDMARDs was associated with an increased risk of abatacept discontinuation (hazard ratio 1.99; p = .002). The most common reasons for abatacept discontinuation were drug switch (11.3%) and loss to follow-up (6.1%). Abatacept was well-tolerated with no new safety signals.

CONCLUSION

The 24-month retention rate of abatacept was 59.9%; abatacept was associated with improved clinical outcomes and was well-tolerated in the real-world setting in Taiwan.

Deciphering the molecular landscape of rheumatoid arthritis offers new insights into the stratified treatment for the condition

Background

For Rheumatoid Arthritis (RA), a long-term chronic illness, it is essential to identify and describe patient subtypes with comparable goal status and molecular biomarkers. This study aims to develop and validate a new subtyping scheme that integrates genome-scale transcriptomic profiles of RA peripheral blood genes, providing a fresh perspective for stratified treatments.

Methods

We utilized independent microarray datasets of RA peripheral blood mononuclear cells (PBMCs). Up-regulated differentially expressed genes (DEGs) were subjected to functional enrichment analysis. Unsupervised cluster analysis was then employed to identify RA peripheral blood gene expression-driven subtypes. We defined three distinct clustering subtypes based on the identified 404 up-regulated DEGs.

Results

Subtype A, named NE-driving, was enriched in pathways related to neutrophil activation and responses to bacteria. Subtype B, termed interferon-driving (IFN-driving), exhibited abundant B cells and showed increased expression of transcripts involved in IFN signaling and defense responses to viruses. In Subtype C, an enrichment of CD8+ T-cells was found, ultimately defining it as CD8+ T-cells-driving. The RA subtyping scheme was validated using the XGBoost machine learning algorithm. We also evaluated the therapeutic outcomes of biological disease-modifying anti-rheumatic drugs.

Conclusions

The findings provide valuable insights for deep stratification, enabling the design of molecular diagnosis and serving as a reference for stratified therapy in RA patients in the future.

The chromatin landscape of pathogenic transcriptional cell states in rheumatoid arthritis

Synovial tissue inflammation is a hallmark of rheumatoid arthritis (RA). Recent work has identified prominent pathogenic cell states in inflamed RA synovial tissue, such as T peripheral helper cells; however, the epigenetic regulation of these states has yet to be defined. Here, we examine genome-wide open chromatin at single-cell resolution in 30 synovial tissue samples, including 12 samples with transcriptional data in multimodal experiments. We identify 24 chromatin classes and predict their associated transcription factors, including a CD8 + GZMK+ class associated with EOMES and a lining fibroblast class associated with AP-1. By integrating with an RA tissue transcriptional atlas, we propose that these chromatin classes represent 'superstates' corresponding to multiple transcriptional cell states. Finally, we demonstrate the utility of this RA tissue chromatin atlas through the associations between disease phenotypes and chromatin class abundance, as well as the nomination of classes mediating the effects of putatively causal RA genetic variants.

Synovial Tissue Insights into Heterogeneity of Rheumatoid Arthritis

PURPOSE OF REVIEW

Rheumatoid arthritis is one of the most common rheumatic and autoimmune diseases. While it can affect many different organ systems, RA primarily involves inflammation in the synovium, the tissue that lines joints. Patients with RA exhibit significant clinical heterogeneity in terms of presence or absence of autoantibodies, degree of permanent deformities, and most importantly, treatment response. These clinical characteristics point to heterogeneity in the cellular and molecular pathogenesis of RA, an area that several recent studies have begun to address.

RECENT FINDINGS

Single-cell RNA-sequencing initiatives and deeper focused studies have revealed several RA-associated cell populations in synovial tissues, including peripheral helper T cells, autoimmunity-associated B cells (ABCs), and NOTCH3+ sublining fibroblasts. Recent large transcriptional studies and translational clinical trials present frameworks to capture cellular and molecular heterogeneity in RA synovium. Technological developments, such as spatial transcriptomics and machine learning, promise to further elucidate the different types of RA synovitis and the biological mechanisms that characterize them, key elements of precision medicine to optimize patient care and outcomes in RA. This review recaps the findings of those recent studies and puts our current knowledge and future challenges into scientific and clinical perspective.

Demographic, Clinical Profile of Rheumatoid Arthritis Patients and Their Association with Disease Severity in Ghana

Background

Rheumatoid arthritis (RA) is one of the frequent chronic, systemic, inflammatory autoimmune disorders with an estimated global prevalence of 1%. RA leads to joint destruction and disability if left untreated. Ghana has seen very few studies on RA, and little is known about the disease's severity and related variables. This study sought to characterize the clinical presentation and determine disease severity and associated risk factors with disease severity among RA patients in a tertiary hospital in Ghana.

Methods

This cross-sectional study was conducted between September 2020 and August 2021. This study included 56 consecutively consenting RA patients from the Komfo Anokye Teaching Hospital orthopaedic unit. Diagnosis of RA was based on the updated American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) 2022 rheumatoid arthritis classification criteria by a rheumatologist. A study questionnaire was used to gather participant demographics and clinical features, and results from the laboratory were taken from the patients' charts and medical records. The patients' disease severity was evaluated based on the rheumatoid arthritis disease activity score, which is based on a 28-joint count (DAS28), and their functioning was evaluated using the modified health assessment questionnaire.

Results

The participants' mean age was 51.25 ± 13.22 years. Out of the total participants, 46 were females, and 10 were males (female-to-male ratio 4.6 : 1). Moreover, 37.50% had arthritis of the hand; 5.30% had severe disease, and 94.60% were not severe. A majority (76.80%) were on methotrexate medication. The most frequently involved joints were the knee (42.90%), wrist (32.10%), and elbow (12.50%). There was no statistically significant association with disease severity and a functional status score of >0.5 (cOR: 10.60, 95% CI (0.52-217.30); p = 0.124). In addition, marital status (p = 0.04), disease duration (p = 0.04), family complaints (p = 0.02), and ESR (p = 0.03) were significantly associated with disease severity.

Conclusion

RA is predominant among elder populations and females. Disease duration, family complaints, and ESR are associated with disease severity. The findings of this study call for interventions towards ensuring early diagnosis of RA among high-risk populations to enhance good management practices.

The association of milk products with rheumatoid arthritis: A cross-sectional study from NHANES

OBJECTIVE

Milk products are a major part of the western diet, but the role of their effect in rheumatoid arthritis (RA) is controversial. The objective of this study was to explore the relationship between milk products and RA in the United States (US) population.

METHODS

In the cross-sectional study, a total of 12,813 participants aged 20years or older were selected from the National Health and Nutrition Examination Survey (NHANES). Consumption of milk products was collected by personal interview, and RA status was obtained by self-reported questionnaires. The association between milk products and RA was estimated by using the weighted logistic regression model.

RESULTS

We found a negative association of once a day or more milk products intake with self-reported RA prevalence (odds ratio [OR]: 0.68; 95% confidence interval [CI]: 0.53 to 0.86; P<0.001). A linear trend between consumption of milk products and the prevalence of RA (P<0.01) was also observed. In subgroup analysis, protective effects of milk products on RA were more pronounced in several groups (i.e., Mexican Americans, highly educated and drinking individuals, etc.). However, no interaction effect of stratification variables and the frequency of milk products intake with RA was detected. After imputing missing data, the sensitivity analysis showed the same association.

CONCLUSION

This study suggested a negative association between consumption of milk products and RA among US population. Further investigations are warranted to validate the causal association and the underlying mechanism.

Drug Delivery System Approaches for Rheumatoid Arthritis Treatment: A Review

Rheumatoid arthritis (RA) is a chronic autoimmune disease that has traditionally been treated using a variety of pharmacological compounds. However, the effectiveness of these treatments is often limited due to challenges associated with their administration. Oral and parenteral routes of drug delivery are often restricted due to issues such as low bioavailability, rapid metabolism, poor absorption, first-pass effect, and severe side effects. In recent years, nanocarrier-based delivery methods have emerged as a promising alternative for overcoming these challenges. Nanocarriers, including nanoparticles, dendrimers, micelles, nanoemulsions, and stimuli-sensitive carriers, possess unique properties that enable efficient drug delivery and targeted therapy. Using nanocarriers makes it possible to circumvent traditional administration routes' limitations. One of the key advantages of nanocarrier- based delivery is the ability to overcome resistance or intolerance to traditional antirheumatic therapies. Moreover, nanocarriers offer improved drug stability, controlled release kinetics, and enhanced solubility, optimizing the therapeutic effect. They can also protect the encapsulated drug, prolonging its circulation time and facilitating sustained release at the target site. This targeted delivery approach ensures a higher concentration of the therapeutic agent at the site of inflammation, leading to improved therapeutic outcomes. This article explores potential developments in nanotherapeutic regimens for RA while providing a comprehensive summary of current approaches based on novel drug delivery systems. In conclusion, nanocarrier-based drug delivery systems have emerged as a promising solution for improving the treatment of rheumatoid arthritis. Further advancements in nanotechnology hold promise for enhancing the efficacy and safety of RA therapies, offering new hope for patients suffering from this debilitating disease.

METTL14-Mediated m6A Modification of TNFAIP3 Involved in Inflammation in Patients With Active Rheumatoid Arthritis

OBJECTIVE

The aim of the study was to investigate the role of N6 -methyladenosine (m6A) modification in the progression of rheumatoid arthritis (RA).

METHODS

Peripheral blood mononuclear cells (PBMCs) from patients with RA and healthy controls were collected. The expression of m6A modification-related proteins and m6A levels were detected using polymerase chain reaction (PCR), western blot, and m6A enzyme-linked immunosorbent assay (ELISA). The roles of methyltransferase-like 14 (METTL14) in the regulation of inflammation in RA was explored using methylated RNA immunoprecipitation (MeRIP) sequencing and RNA immunoprecipitation assays. Collagen antibody-induced arthritis (CAIA) mice were used as an in vivo model to study the role of METTL14 in the inflammation progression of RA.

RESULTS

We found that m6A writer METTL14 and m6A levels were decreased in PBMCs of patients with active RA and correlated negatively with the disease activity score using 28 joint counts (DAS28). Knockdown of METTL14 downregulated m6A and promoted the secretion of inflammatory cytokines interleukin 6 (IL-6) and IL-17 in PBMCs of patients with RA. Consistently, METTL14 knockdown promoted joint inflammation accompanied by upregulation of IL-6 and IL-17 in CAIA mice. MeRIP sequencing and functional studies confirmed that tumor necrosis factor α induced protein 3 (TNFAIP3), a key suppressor of the nuclear factor-κB inflammatory pathway, was involved in m6A-regulated PBMCs. Mechanistic investigations revealed that m6A affected TNFAIP3 expression by regulation of messenger RNA stability and translocation in TNFAIP3 protein coding sequence.

CONCLUSIONS

Our study highlights the critical roles of m6A on regulation of inflammation in RA progression. Treatment strategies targeting m6A modification may represent a new option for management of RA.

Identification and Development of Synovial B-Cell-Related Genes Diagnostic Signature for Rheumatoid Arthritis

Background

The aim of the study was to investigate the landscape of B-cell-related gene expression profiling in rheumatoid arthritis (RA) synovium and explore the biological and clinical significance of these genes in RA.

Methods

Expression profiling of synovial biopsies from subjects with 152 RA patients, 22 osteoarthritis (OA) patients, and 28 healthy controls was downloaded from the Gene Expression Omnibus database. Single-sample gene set enrichment analysis (ssGSEA) was performed to evaluate the abundance of infiltrated immune cells, and the results were validated using immunohistochemical staining. GSEA was employed to decipher differences in B-cell-related biological pathways. B-cell-related differential expression genes (BRDEGs) were screened, and BRDEGs-based model was developed by machine learning algorithms and evaluated by an external validation set and clinical RA cohort, then biological functions were further analyzed.

Results

High levels of immune cell infiltration and B-cell-related pathway activation were revealed in RA synovium. BRDEGs were screened, and three key molecular markers consisting of FAS, GPR183, and TFRC were identified. The diagnosis model was established, and these gene markers have good discriminative ability for RA. Molecular pathological evaluation confirmed RA patients with high-risk scores presented higher levels of B-cell activation and RA characteristics. In addition, a competitive endogenous RNA network was established to elucidate the molecular mechanisms of the posttranscriptional network.

Conclusions

We described the B-cell-related molecular landscape of RA synovium and constructed a molecular diagnostic model in RA. The three genes FAS, GPR183, and TFRC may be potential targets for clinical diagnosis and immunoregulatory therapy of RA.

Genetic association between interleukin-17 and susceptibility to rheumatoid arthritis

BACKGROUND

The pathogenesis of rheumatoid arthritis (RA) is an immune imbalance, in which various inflammatory immune cells and pro-inflammatory factors are involved. Interleukin-17 (IL-17), a potent pro-inflammatory cytokine, has been found to have increased expression in the joints of patients with RA compared to healthy individuals. However, the causal relationship between the expression level of IL-17 or IL-17 receptor (IL-17R) and RA remained unknown. In this study, two-sample Mendelian randomization (MR) was used to investigate the causal relationship between IL-17 and RA.

METHODS

Summary statistics for RA (14,361 RA cases and 43,923 healthy controls) and IL-17 (3,301 samples) were obtained from an available meta-analysis of published genome-wide association studies (GWAS). Relevant single nucleotide polymorphisms (SNPs) were selected by executing quality control steps from the GWAS summary results. Then we used bi-directional two-sample Mendelian randomization (MR) and multi-variable MR (MVMR) analysis to examine evidence of causality. MR and MVMR analyses progressed mainly using inverse variance weighted (IVW), weighted median (WM), and MR-Egger regression methods, which were applied to the genetic instrumental variables (IVs) of IL-17A/IL-17 RA, IL-17C/IL-17 RC, and IL-17D/IL-17RD and RA. For assessing the robustness of the results, we also carried out a sensitivity analysis to assess heterogeneity and pleiotropy, such as MR-Egger, leave-one-out, and MR pleiotropy residual sum and outlier (MR-PRESSO).

RESULTS

Two-sample MR Analysis showed the causal relationship between IL-17A/IL-17RA and RA. The presence of genetically high IL-17A/IL-17RA may increase the risk of RA (IL-17A(OR = 1.095; 95% C.I., 0.990-1.210, p.adj = 0.013), IL-17RA(OR = 1.113, 95%CI = 1.006-1.231, p.adj = 0.006)). However, the results indicated that IL-17C/IL-17RC, and IL-17D/IL-17RD demonstrated no causal impact on RA (IL-17C(OR = 1.007, 95%CI = 0.890-1.139, p.adj = 0.152), IL-17RC(OR = 1.006, 95%CI = 0.904-1.119, p.adj = 0.152), IL-17D(OR = 0.979, 95%CI = 0.843-1.137, p.adj = 0.130), IL-17RD(OR = 0.983, 95%CI = 0.876-1.104, p.adj = 0.129)). Furthermore, MVMR analysis shown that IL-17RA(OR = 1.049, 95% CI: 0.997-1.102, p.adj = 0.014) was associated with increased risk of RA. Sensitivity analysis showed no heterogeneity and pleiotropy, suggesting that the above results were robust and reliable.

CONCLUSION

The MR analysis provides evidence that IL-17A/IL-17RA are risk factors for RA. This emphasizes the importance of intervention on IL-17A/IL-17RA in patients with RA. Developing drugs that limit IL-17A may reduce the risk of RA.

Deconstruction of rheumatoid arthritis synovium defines inflammatory subtypes

Rheumatoid arthritis is a prototypical autoimmune disease that causes joint inflammation and destruction1. There is currently no cure for rheumatoid arthritis, and the effectiveness of treatments varies across patients, suggesting an undefined pathogenic diversity1,2. Here, to deconstruct the cell states and pathways that characterize this pathogenic heterogeneity, we profiled the full spectrum of cells in inflamed synovium from patients with rheumatoid arthritis. We used multi-modal single-cell RNA-sequencing and surface protein data coupled with histology of synovial tissue from 79 donors to build single-cell atlas of rheumatoid arthritis synovial tissue that includes more than 314,000 cells. We stratified tissues into six groups, referred to as cell-type abundance phenotypes (CTAPs), each characterized by selectively enriched cell states. These CTAPs demonstrate the diversity of synovial inflammation in rheumatoid arthritis, ranging from samples enriched for T and B cells to those largely lacking lymphocytes. Disease-relevant cell states, cytokines, risk genes, histology and serology metrics are associated with particular CTAPs. CTAPs are dynamic and can predict treatment response, highlighting the clinical utility of classifying rheumatoid arthritis synovial phenotypes. This comprehensive atlas and molecular, tissue-based stratification of rheumatoid arthritis synovial tissue reveal new insights into rheumatoid arthritis pathology and heterogeneity that could inform novel targeted treatments.

Inappropriate treatment response to DMARDs: A pathway to difficult-to-treat rheumatoid arthritis

In recent years, difficult-to-treat rheumatoid arthritis (D2T RA) has attracted significant attention from rheumatologists due to its poor treatment response and the persistent symptoms or signs experienced by patients. The therapeutic demands of patients with D2T RA are not properly met due to unclear pathogenic causes and a lack of high-quality data for current treatment options, creating considerable management difficulties with this patient population. This review describes the clinical challenges associated with disease-modifying antirheumatic drugs (DMARDs) and explores contributing factors associated with inappropriate response to DMARDs that may lead to D2T RA and related immunological dysregulation. It is now understood that D2T RA is a highly heterogeneous pathological status that involves multiple factors. These factors include but are not limited to genetics, environment, immunogenicity, comorbidities, adverse drug reactions, inappropriate drug application, poor adherence, and socioeconomic status. Besides, these factors may manifest in the selection and utilization of specific DMARDs, either individually or in combination, thereby contributing to inadequate treatment response. Finding these variables may offer hints for enhancing DMARD therapy plans and bettering the condition of D2T RA patients.

Single Nucleotide Polymorphisms Associated with Rheumatoid Arthritis in Saudi Patients

Rheumatoid arthritis (RA) is a complex, multifactorial disorder with an autoimmune etiology. RA is highly heritable and is associated with both human leucocyte antigen (HLA) and non-HLA genes. We investigated the associations of 33 single nucleotide polymorphisms (SNPs) with RA in the Saudi population.

METHODS

This study included 105 patients with RA and an equal number of age- and sex-matched controls. The patients with RA attended outpatient clinics at King Khalid University Hospital in Riyadh, Saudi Arabia. Blood samples were collected, and DNA was extracted using Qiagen kits. Primers were designed for the 33 selected SNPs using the MassEXTEND primers program, and samples were genotyped on the Sequenom MassARRAY iPLEX platform. The allele frequencies and genotypes were determined for each SNP, and the results obtained for the patients were compared to those for the controls.

RESULTS

The allele and genotype frequencies of six SNPs were significantly associated with RA: rs1188934, rs10919563, rs3087243, rs1980422, rs10499194, and rs629326. The minor alleles of rs1188934, rs10919563, rs10499194, and rs629326 were protective, with odds ratios of 0.542, 0.597, 0.589, and 0.625, and p-values of 0.002, 0.023, 0.013 and 0.036, respectively. In addition, the heterozygote frequencies of two SNPs (rs6859219 and rs11586238) were significantly higher in the controls than in the patients.

CONCLUSIONS

There is considerable heterogeneity in the genetics of RA in different populations, and the SNPs that are associated with RA in some populations are not in others. We studied 33 SNPs and only eight were associated with RA. The remaining SNPs showed no allelic or genotypic associations with RA.

Estimating Patient-Specific Relative Benefit of Adding Biologics to Conventional Rheumatoid Arthritis Treatment: An Individual Participant Data Meta-Analysis

Importance

Current evidence remains ambiguous regarding whether biologics should be added to conventional treatment of rheumatoid arthritis for specific patients, which may cause potential overuse or treatment delay.

Objectives

To estimate the benefit of adding biologics to conventional antirheumatic drugs for the treatment of rheumatoid arthritis given baseline characteristics.

Data Sources

Cochrane CENTRAL, Scopus, MEDLINE, and the World Health Organization International Clinical Trials Registry Platform were searched for articles published from database inception to March 2, 2022.

Study Selection

Randomized clinical trials comparing certolizumab plus conventional antirheumatic drugs with placebo plus conventional drugs were selected.

Data Extraction and Synthesis

Individual participant data of the prespecified outcomes and covariates were acquired from the Vivli database. A 2-stage model was fitted to estimate patient-specific relative outcomes of adding certolizumab vs conventional drugs only. Stage 1 was a penalized logistic regression model to estimate the baseline expected probability of the outcome regardless of treatment using baseline characteristics. Stage 2 was a bayesian individual participant data meta-regression model to estimate the relative outcomes for a particular baseline expected probability. Patient-specific results were displayed interactively on an application based on a 2-stage model.

Main Outcomes and Measures

The primary outcome was low disease activity or remission at 3 months, defined by 3 disease activity indexes (ie, Disease Activity Score based on the evaluation of 28 joints, Clinical Disease Activity Index, or Simplified Disease Activity Index).

Results

Individual participant data were obtained from 3790 patients (2996 female [79.1%] and 794 male [20.9%]; mean [SD] age, 52.7 [12.3] years) from 5 large randomized clinical trials for moderate to high activity rheumatoid arthritis with usable data for 22 prespecified baseline covariates. Overall, adding certolizumab was associated with a higher probability of reaching low disease activity. The odds ratio for patients with an average baseline expected probability of the outcome was 6.31 (95% credible interval, 2.22-15.25). However, the benefits differed in patients with different baseline characteristics. For example, the estimated risk difference was smaller than 10% for patients with either low or high baseline expected probability.

Conclusions and Relevance

In this individual participant data meta-analysis, adding certolizumab was associated with more effectiveness for rheumatoid arthritis in general. However, the benefit was uncertain for patients with low or high baseline expected probability, for whom other evaluations were necessary. The interactive application displaying individual estimates may help with treatment selection.

The Chromatin Landscape of Pathogenic Transcriptional Cell States in Rheumatoid Arthritis

Synovial tissue inflammation is the hallmark of rheumatoid arthritis (RA). Recent work has identified prominent pathogenic cell states in inflamed RA synovial tissue, such as T peripheral helper cells; however, the epigenetic regulation of these states has yet to be defined. We measured genome-wide open chromatin at single cell resolution from 30 synovial tissue samples, including 12 samples with transcriptional data in multimodal experiments. We identified 24 chromatin classes and predicted their associated transcription factors, including a CD8+ GZMK+ class associated with EOMES and a lining fibroblast class associated with AP-1. By integrating an RA tissue transcriptional atlas, we found that the chromatin classes represented 'superstates' corresponding to multiple transcriptional cell states. Finally, we demonstrated the utility of this RA tissue chromatin atlas through the associations between disease phenotypes and chromatin class abundance as well as the nomination of classes mediating the effects of putatively causal RA genetic variants.

LCK, FOXC1 and hsa-miR-146a-5p as potential immune effector molecules associated with rheumatoid arthritis

Rheumatoid arthritis (RA) is a type of systemic immune disease characterized by chronic inflammatory disease of the joints. However, the aetiology and underlying molecular events of RA are unclear. Here, we applied bioinformatics analysis to identify potential immune effector molecules involved in RA. The three microarray datasets were downloaded from the Gene Expression Omnibus (GEO) database. We used the R software screen 115 overlapping differentially expressed genes (DEGs). Subsequently, we constructed a protein-protein interaction (PPI) network encoded by these DEGs and identified 10 genes closely associated with RA - LCK, GZMA, GZMB, CD2, LAG3, IL-15, TNFRSF4, CD247, CCR5 and CCR7. Furthermore, in the miRNA-hub gene networks, we screened out hsa-miR-146a-5p, which is the miRNA controlling the largest number of hub genes. Finally, we found some transcription factors that closely interact with hub genes, such as FOXC1, GATA2, YY1, RUNX2, SREBF1, CEBPB and NFIC. This study successfully predicted that LCK, FOXC1 and hsa-miR-146a-5p can be used as potential immune effector molecules of RA. Our study may have potential implications for future prediction of disease progression in patients with symptomatic RA, and has important significance for the pathogenesis and targeted therapy of RA.

Appearance of Ankylosing Spondylitis in a Middle-Aged Female Patient With a Long History of Rheumatoid Arthritis

Ankylosing spondylitis (AS) is a chronic inflammatory disease of the axial bones, primarily affecting the spine. AS is classified as spondyloarthritis because it affects the spine and other joints. AS has several presentations and, in some cases, can be insidious, making it difficult to diagnose. We encountered a patient on long-term follow-up for rheumatoid arthritis with an appearance of AS. This case suggests that patients with long-term rheumatoid arthritis can develop AS during follow-up and that the seropositivity of rheumatoid factors and anti-cyclic citrullinated peptide antibodies cannot rule out AS. Therefore, the possibility of AS should be considered, even in patients diagnosed with rheumatoid arthritis.

Assessment of Angiopoietin-2 Single Nucleotide Polymorphism in Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease that destroys joint cartilage and causes disability. Synovial inflammation, with angiogenesis, is an early event in the progression of the disease. Angiopoietin 2 (ANGPT2) is a cytokine with both inflammatory and angiogenic effects. Many genes can influence RA susceptibility and disease activity. The aim is to assess the relationship between ANGPT2 gene polymorphism (rs3020221) and RA. The study was a case-control study that included 212 RA patients and 238 age-and gender-matched healthy volunteers. RA disease activity was assessed using the Disease Activity Score 28 index. Erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, and antibody to cyclic citrullinated peptide were measured. ANGPT2 rs3020221 C > T SNP genotyping was done using real-time polymerase chain reaction (PCR). The TT genotype was more frequently represented in RA patients than in healthy controls (18.9% and 7.1%, respectively, p < 0.001) and increased the chance of developing RA four-fold, as compared to other genotypes (OR = 4.00, 95% CI = 2.09-7.63) (p < 0.001). The CT genotype was associated with elevated levels of the inflammatory markers ESR and CRP in RA patients (p = 0.012 and 0.037, respectively) as well as the DAS28 ESR Score (p < 0.001). The presence of the T allele either under the dominant model (for genotypes CT and TT) or the recessive model (for the genotype TT) predicts RA disease. Assessment of ANGPT2 gene polymorphism is useful to predict the patients with susceptibility to RA. The presence of T allele increased the risk of developing RA disease by two folds.

Ocular manifestations of rheumatoid arthritis

PURPOSE OF REVIEW

This article summarizes the pathophysiology of rheumatoid arthritis and common ocular manifestations that it is associated with: keratoconjunctivitis sicca, episcleritis, scleritis, and peripheral ulcerative keratitis.

RECENT FINDINGS

Newer biologic agents are being used to effectively treat rheumatoid arthritis and its ocular manifestations.

SUMMARY

The eye is a frequent extra-articular site of inflammation in patients with rheumatoid arthritis. Ocular involvement can range from more benign conditions such as keratoconjunctivitis sicca and episcleritis, to potentially vision and globe-threatening diseases like scleritis and peripheral ulcerative keratitis. Clinicians should be aware of these ophthalmic manifestations and the various treatment options that are available. Coordination between ophthalmology and rheumatology is helpful in the treatment of these patients.

Sustained DMARD-free remission in rheumatoid arthritis - about concepts and moving towards practice

Sustained DMARD-free remission (SDFR) is the best possible outcome in RA. It is characterized by sustained absence of clinical arthritis, which is accompanied by resolution of symptoms and restoration of normal physical functioning. Therefore it's the best proxy for cure in RA. The mechanisms underlying SDFR-development are yet unidentified. Hypothetically, there are two possible scenarios. The first hypothesis is based on the concept of regaining immune-tolerance, which implies that RA-patients are similar at diagnosis and that disease-processes during the disease-course shift into a favorable direction, resulting in regaining a state in which arthritis is persistently absent. This could imply that SDFR is theoretically achievable for all RA-patients. The alternative hypothesis is that RA-patients who achieve SDFR are intrinsically different from those who cannot. This would imply that DMARD-cessation could be restricted to a subgroup of RA-patients. Since the 1990s, DMARD-discontinuation and SDFR have been increasingly studied as long-term-outcome in RA. In this review, we describe hitherto results of clinical, genetic, serological, histological and imaging studies and looked for arguments for the first or second hypothesis in both auto-antibody-positive and auto-antibody-negative RA. In auto-antibody-negative RA, SDFR is presumably restricted to a subgroup of patients with high serological-markers of inflammation at diagnosis and a rapid and sustained decrease in inflammation after treatment-start. Identifying these RA-patients could be helpful in realizing personalized-medicine. In auto-antibody-positive RA, only few patients achieve SDFR and no definite conclusions can be drawn, but data could suggest that SDFR-patients might be a subgroup with relatively low inflammation from disease-presentation onwards.

Phytochemicals from medicinal plants from African forests with potentials in rheumatoid arthritis management

OBJECTIVES

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by inflammation, pain, and cartilage and bone damage. There is currently no cure for RA. It is however managed using nonsteroidal anti-inflammatory drugs, corticosteroids and disease-modifying anti-rheumatic drugs, often with severe side effects. Hidden within Africa's lush vegetation are plants with diverse medicinal properties including anti-RA potentials. This paper reviews the scientific literature for medicinal plants, growing in Africa, with reported anti-RA activities and identifies the most abundant phytochemicals deserving research attention. A search of relevant published scientific literature, using the major search engines, such as Pubmed/Medline, Scopus, Google Scholar, etc. was conducted to identify medicinal plants, growing in Africa, with anti-RA potentials.

KEY FINDINGS

Twenty plants belonging to 17 families were identified. The plants are rich in phytochemicals, predominantly quercetin, rutin, catechin, kaempferol, etc., known to affect some pathways relevant in RA initiation and progression, and therefore useful in its management.

SUMMARY

Targeted research is needed to unlock the potentials of medicinal plants by developing easy-to-use technologies for preparing medicines from them. Research attention should focus on how best to exploit the major phytochemicals identified in this review for the development of anti-RA 'green pharmaceuticals'.

Recent progress in therapeutic strategies and biomimetic nanomedicines for rheumatoid arthritis treatment

INTRODUCTION

Rheumatoid arthritis (RA) is an autoimmune systemic disease in which inflammatory and immune cells accumulate in inflamed joints. Researchers aimed at the characteristics of RA to achieve the effect of treating RA through different therapeutic strategies, and have used various endogenous materials to design drug-loaded nanoparticles that can target RA by binding to cell adhesion molecules or chemokines. In some cases, the nanoparticles can respond to the characteristics of the microenvironment.

AREAS COVERED

This article reviews the recent advances in the treatment of RA from two aspects of therapeutic strategies and delivery strategies. Therapeutic strategies mainly include neutralization of inflammatory factors, promotion of inflammatory cell apoptosis, ROS scavenger, immunosuppression, and bone tissue repair. The drug delivery strategy is mainly described from two aspects: chemically functionalized biomimetic nanoparticles and endogenous nanoparticles.

EXPERT OPINION

Biomimetic NPs may be effective drug carriers for targeted RA treatment. NPs can reduce the clearance of mononuclear phagocytes, prolong the blood circulation time, and improve the targeting ability. With the deepening of research, more and more biomimetic NPs have entered the clinical trial stage. However, safe and scalable preparation methods are needed to improve their clinical applicability.

Network Pharmacology Analysis and Experimental Validation to Investigate the Mechanism of Total Flavonoids of Rhizoma Drynariae in Treating Rheumatoid Arthritis

Objective

The study aimed to explore the mechanism of total flavonoids of Rhizoma Drynariae (TFRD) in the treatment of rheumatoid arthritis (RA) based on network pharmacology and experimental validation.

Methods

The active components of TFRD were identified from TCMSP and TCMID databases. Relevant targets of the active compounds of TFRD and RA-related targets were predicted by public databases online. A component-target (C-T) regulatory network was constructed by Cytoscape. The genes of TFRD regulating RA were imported into STRING database to construct a protein-protein interaction (PPI) network in order to predict the key targets. KEGG enrichment analysis was performed to predict the crucial mechanism of TFRD against RA. The active components of TFRD underwent molecular docking with the key proteins. Collagen-induced arthritis (CIA) model of rats and inflammatory factors-stimulated fibroblast-like synoviocytes were used in vivo and in vitro to validate the efficacy and predicted critical mechanisms of TFRD.

Results

Network Pharmacology analysis revealed that TFRD had 14 active compounds, corresponding to 213 targets, and RA related to 2814 genes. There were 137 intersection genes between TFRD and RA. KEGG indicated that therapeutic effects of TFRD on RA involves T cell receptor signaling pathway, Th17 cell differentiation, IL-17 signaling pathway, TNF signaling pathway, MAPK signaling pathway and PI3K/AKT signaling pathway. In vivo experiments suggested TFRD can alleviate the inflammatory response, joint swelling and synovial abnormality of CIA rats. TFRD contributed to the decrease of Th17 cells and the down-regulated secretion of IL-17A and TNF-α of activated lymphocyte in CIA model. In vitro experiments confirmed TFRD can effectively inhibit the inflammatory response of fibroblast-like synoviocytes and suppress the abnormal activation of MAPK, PI3K/AKT and NFκB signaling pathways.

Conclusion

The treatment of RA with TFRD is closely related to inhibiting Th17 differentiation and inflammatory response of synoviocytes.

Frequency of serological markers of rheumatoid arthritis in patients with IgA anti-β2 glycoprotein I antibodies

Aim

To determine the frequency of serological markers of RA in patients with anti‐β2 glycoprotein I antibodies (aβ2GPI) of IgA isotype.

Material and Methods

A retrospective study was conducted on 67 patients with aβ2GPI‐IgA. Ninety healthy blood donors (HBD) were used as a control group. IgG anti‐cyclic citrullinated peptides antibodies (CCP‐Ab) and rheumatoid factors (RF) IgG, IgA, and IgM were detected by enzyme‐linked immunosorbent assay (ELISA).

Results

Seventeen patients and eight HBD had CCP‐Ab and/or RF (25.4% vs. 8.9%, p = 0.005, CI 95% [14.95; 35.79], odds ratio = 3.5). The frequency of CCP‐Ab was significantly higher in patients than in healthy subjects (14.9% vs. 3.3%, p = 0.009). IgA isotype of RF was significantly higher in patients than in controls (7.5% vs. 0%, p = 0.02). In male patients, CCP‐Ab and/or RF were more frequent than in healthy male subjects (37.5% vs. 11.8%, p = 0.02). In patients, no correlation was found between the levels of aβ2GPI‐IgA and CCP‐Ab (r = 0.082, p = 0.51). There was no correlation between the level aβ2GPI‐IgA and the level of the isotypes of RF (IgG, IgA, and IgM) in patients (r = 0.1, p = 0.37; r = 0.17, p = 0.17 and r = 0.07, p = 0.59 respectively).

Conclusion

Frequencies of CCP‐Ab and RF are high in patients with aβ2GPI‐IgA suggesting that these patients are susceptible to developing RA.

Employment, health visits, mental health, and mortality in parents with a chronically ill child: a Danish nationwide population-based cohort study

Chronic diseases in children can impact their parents; this may be overlooked in a clinical setting. Our aim was to investigate associations of chronic diseases in children with their parents' employment, health care utilization, mental health, and mortality. In a matched cohort study using nationwide and population-based data in Denmark, we included parents to children (< 18 years) with acute disseminated encephalomyelitis, multiple sclerosis, type 1 diabetes, inflammatory bowel disease, and rheumatoid arthritis/juvenile idiopathic arthritis during 2008-2015. The reference group was parents to unaffected children. Outcomes were parental employment (early retirement, cash benefits, income), health care utilization (e.g., general practitioner, or hospital visits), mental health (visits to psychiatry/psychology clinics, antidepressant drug redemptions), and mortality. We included 13,769 parents with a chronically ill child and 138,606 control parents. Annual income was unaffected for two-parent families after the child's disease onset, but two-parent families had increased hazard of early retirement of 25% (95% CI = 1.01-1.54; p = 0.04). Parents with a chronically ill child had (a) increased rate of antidepressant drug redemptions or psychology/psychiatry visits (hazard ratio 1.37; 95% CI = 1.28-1.46 at 1-year follow-up); (b) increased health care utilization, with an increased marginal mean in primary care of 1% (95% CI = 1.00-1.02; p = 0.005), hospital-affiliated visits of 19% (95% CI = 1.14-1.24; p < 0.0001), and hospital admissions of 14% (95% CI = 1.09-1.20; p < 0.0001); and (c) 69% increased mortality hazard (95% CI = 1.30-2.18; p < 0.0001) in parents younger than 50 years with no comorbidities, albeit small in absolute numbers.

CONCLUSION

Pediatric chronic diseases were negatively associated with parental employment, mental health, and mortality, and increased health care utilization.

WHAT IS KNOWN

• Studies on the impact of pediatric chronic diseases on parental health are qualitative. • Knowledge is unavailable regarding the impact on parental work, health care utilization, and mortality.

WHAT IS NEW

• Among 13,769 parents with a chronically ill child and 138,606 control parents, parents with a chronically ill child had 37% increased antidepressant drug redemptions, and these parents <50 years without comorbidities had 69% increased mortality hazard. • Medical doctors should consider the parental health condition and societal challenges related to having child with a chronic disease.

A CD40 variant is associated with systemic bone loss among patients with rheumatoid arthritis

OBJECTIVES

Little is known about genes predisposing to systemic bone loss (SBL) in rheumatoid arthritis (RA). Therefore, we examined the association between SBL and variants of genes playing a critical role in both immune response and bone homeostasis among patients with RA.

METHODS

IRAK-1 rs3027898, IRAK-2 rs3844283, IRAK-2 rs708035, IFIH1 rs1990760, CD40 rs48104850, TNFAIP3 rs2230926, and miR146-a rs2910164 were genotyped in 176 adult RA patients. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (DXA).

RESULTS

Low BMD was observed in 116 (65.9%) patients. Among them, 60 (34.1%) had low femoral neck (FN) Z score, 72 (40.9%) had low total femur (TF) Z score, and 105 (59.6%) had low lumbar spine (LS) Z score. Among all the SNPs assessed, only CD40 rs4810485 was found to be associated with reduced TF Z score with the CD40 rs4810485 T allele protecting against reduced TF Z score (OR = 0.40, 95% CI = 0.23-0.68, p = 0.0005). This association was confirmed in the multivariate logistic regression analysis (OR = 0.31, 95% CI = 0.16-0.59, p = 3.84 × 10^-4). Moreover, median FN BMD was reduced among RA patients with CD40 rs4810485 GG genotype compared to RA patients harbouring CD40 rs4810485 TT and GT genotypes (0.788 ± 0.136 versus 0.826 ± 0.146 g/cm², p = 0.001). IRAK-1 rs3027898, IRAK-2 rs3844283, rs708035, IFIH rs1990760, TNFAIP3 rs2230926, and miR146-a rs2910164 were not found to be associated with SBL.

CONCLUSION

This study for the first time ever demonstrated an association between a CD40 genetic variant and SBL among patients with RA.

KEY POINTS

• CD40 rs4810485 GG genotype is associated with decreased BMD among patients with RA. • CD40 rs4810485 might serve as a genetic marker for SBL in RA. • CD40 genetic variations might be integrated in future development of more effective therapeutic interventions for prevention of SBL in RA.

OUP accepted manuscript

Rheumatoid arthritis (RA) and osteoporosis (OP) are two comorbid complex inflammatory conditions with evidence of shared genetic background and causal relationships. We aimed to clarify the genetic architecture underlying RA and various OP phenotypes while additionally considering an inflammatory component, C-reactive protein (CRP). Genome-wide association study summary statistics were acquired from the GEnetic Factors for OSteoporosis Consortium, Cohorts for Heart and Aging Research Consortium and UK Biobank. Mendelian randomization (MR) was used to detect the presence of causal relationships. Colocalization analysis was performed to determine shared genetic variants between CRP and OP phenotypes. Analysis of pleiotropy between traits owing to shared causal single nucleotide polymorphisms (SNPs) was performed using PL eiotropic A nalysis under CO mposite null hypothesis (PLACO). MR analysis was suggestive of horizontal pleiotropy between RA and OP traits. RA was a significant causal risk factor for CRP (β = 0.027, 95% confidence interval = 0.016–0.038). There was no evidence of CRP→OP causal relationship, but horizontal pleiotropy was apparent. Colocalization established shared genomic regions between CRP and OP, including GCKR and SERPINA1 genes. Pleiotropy arising from shared causal SNPs revealed through the colocalization analysis was all confirmed by PLACO. These genes were found to be involved in the same molecular function ‘protein binding’ (GO:0005515) associated with RA, OP and CRP. We identified three major components explaining the epidemiological relationship among RA, OP and inflammation: (1) Pleiotropy explains a portion of the shared genetic relationship between RA and OP, albeit polygenically; (2) RA contributes to CRP elevation and (3) CRP, which is influenced by RA, demonstrated pleiotropy with OP.

Relationship of serum copper and HLADR4 tissue typing to disease activity and severity in patients with rheumatoid arthritis: A cross sectional study

Background

Objective

Methods

Results

Conclusions

•

Rheumatoid arthritis is a chronic disease associated with high burden on individuals.

•

Serum copper increases in active disease.

•

Assessment of disease activity helps in treatment and follow up.

•

Positive HLADR4 tissue typing is associated with severe disease and complications.

Clinical utility of therapy selection informed by predicted nonresponse to tumor necrosis factor-ɑ inhibitors: an analysis from the Study to Accelerate Information of Molecular Signatures (AIMS) in rheumatoid arthritis

BACKGROUND

The molecular signature response classifier (MSRC) is a blood-based precision medicine test that predicts nonresponders to tumor necrosis factor-ɑ inhibitors (TNFi) in rheumatoid arthritis (RA) so that patients with a molecular signature of non-response to TNFi can be directed to a treatment with an alternative mechanism of action.

RESEARCH DESIGN AND METHODS

This study evaluated decision choice and treatment outcomes resulting from MSRC-informed treatment selection within a real-world cohort.

RESULTS

Therapy selection by providers was informed by MSRC results for 73.5% (277/377) of patients. When MSRC results were not incorporated into decision-making, 62.0% (62/100) of providers reported deviating from test recommendations due to insurance-related restrictions. The 24-week ACR50 responses in patients prescribed a therapy in alignment with MSRC results were 39.6%. Patients with a molecular signature of non-response had significantly improved responses to non-TNFi therapies compared with TNFi therapies (ACR50 34.8% vs 10.3%, p-value = 0.05). This indicates that predicted non-responders to TNFi therapies are not nonresponders to other classes of RA targeted therapy. Significant changes were also observed for CDAI, ACR20, ACR70, and for responses at 12 weeks.

CONCLUSIONS

Adoption of the MSRC into patient care could fundamentally shift treatment paradigms in RA, resulting in substantial improvements in real-world treatment outcomes.

Rheumatoid Arthritis in Silica-Exposed Workers

Few studies have examined rheumatoid arthritis (RA) risk and severity in Korean workers exposed to silica. We compared the hospitalization risk of RA between silica-exposed workers and the general Korean population. The study cohort consisted of male workers exposed to silica who had undergone at least one silica-associated special medical examination between 1 January 2000 and 31 December 2004 (N = 149,948). The data were from the Korea Occupation Safety and Health Agency. RA morbidity based on hospital admission records was estimated from 2000 to 2005 using the Korea National Health Insurance Service claims data. The standardized admission ratio (SAR) was calculated by dividing the observed number of admissions in silica-exposed workers by the expected number of admissions in the general reference population. For the sum of “Seropositive rheumatoid arthritis” (M05) and “Other rheumatoid arthritis” (M06), the SAR was higher in the silica-exposed group (1.34, 95% CI 1.08–1.64). For M05, workers with <10 years of silica exposure had a significantly higher SAR (2.54, 95% CI 1.10–5.01) than the general population. More silica-exposed workers without a diagnosis of pneumoconiosis were hospitalized for RA than the general population. Our analysis reaffirms the link between silica exposure and RA and suggests that the severity of RA is increased by silica. Further studies of silica-exposed workers with longer follow-up are needed.

Novel Roles of the Tim Family in Immune Regulation and Autoimmune Diseases

T cell Ig and mucin domain (Tim) protein family members were identified to be important regulators of the immune response. As their name indicates, Tim proteins were originally considered a T cell-specific markers, and they mainly regulate the responses of T helper cells. However, accumulating evidence indicates that Tims are also expressed on antigen-presenting cells (APCs), such as monocytes, macrophages, dendritic cells (DCs) and B cells, and even plays various roles in natural killer cells (NKs) and mast cells. In recent years, the expression and function of Tims on different cells and the identification of new ligands for the Tim family have suggested that the Tim family plays a crucial role in immune regulation. In addition, the relationship between Tim family gene polymorphisms and susceptibility to several autoimmune diseases has expanded our knowledge of the role of Tim proteins in immune regulation. In this review, we discuss how the Tim family affects immunomodulatory function and the potential role of the Tim family in typical autoimmune diseases, including multiple sclerosis (MS), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and type 1 diabetes (T1D). A deeper understanding of the immunoregulatory mechanism of the Tim family might provide new insights into the clinical diagnosis and treatment of autoimmune diseases.

Knowledge of disease, diagnosis, adherence and impact of research in an Irish cohort of patients with inflammatory arthritis

Background: Patient engagement with clinicians results in shared decision making and increased adherence to medication. However, in order for strong patient: clinician partnerships to be achieved, communication barriers need to be identified. Therefore, the aim of this study was to examine the level of understanding of inflammatory arthritis patients and the need for strong patient-partnership in research. Methods: An online anonymous survey was distributed to patients living with inflammatory arthritis which addressed questions about diagnosis, routine tests, medications and how they work, medication adherence, disease flare, heredity, pregnancy, and patient involvement in research. Results: There were 1,873 respondents, 1416 of which had inflammatory arthritis (IA)- rheumatoid arthritis (RA) (65.8%) and psoriatic arthritis (PsA) (34.2%). They were predominantly female (RA 86%, PsA 85 %), aged 55±13 and 50±12 years. Less than 35% of patients had an understanding of diagnostic tests, what was measured and the implication for disease, with 75.5% also concerned about heredity. There was a high level of understanding of how specific medications treat inflammatory arthritis (72.9%). Adherence was also very high (>87%), with the main reasons for stopping medication without the advice of their clinician,  ‘feeling better’ and ‘side effects’ however  a significant proportion of patients (69.9%) reported a disease-flare following cessation of medication. Patients (31%) were also concerned that inflammatory arthritis reduced their chances of getting pregnant, with only 8% believing arthritis medications were safe to take during pregnancy. Finally, only 9% of patients had ever been asked to participate in a research study. Conclusions: This study demonstrates a need for the development of stronger patient-partnerships with clinicians and researchers in relation to patient education and engagement with research, to create a platform where patients can have meaningful input and involvement in future research studies.

HLA-DRB1, IRF5, and CD28 gene polymorphisms in Egyptian patients with rheumatoid arthritis: susceptibility and disease activity

This study was established to assess the effects of IRF5 rs10488631 and CD28 rs1980422 single-nucleotide polymorphisms (SNPs) and HLA-DRB1 shared epitope (SE) allele on the prognosis and disease activity of rheumatoid arthritis (RA) patients. A total of 150 RA patients and 150 healthy controls were genotyped for the selected SNPs by real-time PCR. HLA-DRB1 SE was determined using LAB Type SSO Class II DRB1 typing. Our results suggest that HLA-DRB1, CD28, and IRF5 significantly discriminated (p < 0.001) RA patients and healthy controls (OR of single HLA-DRB1 SE allele = 2.431, CI = 1.467-4.027, OR of two SE alleles = 11.152, CI = 2.479-50.159), (OR of CD28 risk allele C = 2.794, 95% CI = 1.973-3.956) and (OR of IRF5 risk allele C = 4.925, CI = 3.26-7.439). Rheumatoid factor (RF) seropositivity was associated with HLA-DRB1 SE (p < 0.001) and IRF5 risk allele (p < 0.001). ACPA was significantly associated only with IRF5 risk allele (p < 0.001). A better response to methotrexate therapy was found in HLA-DRB1 SE non-carriers, and CD28 TT patients. This study demonstrated associations of HLA-DRB1 SE, CD28, and IRF5 with the risk of RA. HLA-DRB1 SE and CD28 rs1980422 can be used as predictors of methotrexate therapy response.

Association of AFF3 Gene Polymorphism rs10865035 with Rheumatoid Arthritis: A Population-Based Case-Control Study on a Pakistani Cohort

Rheumatoid arthritis (RA) is one of the complex diseases with the involvement of the genetic as well as environmental factors in its onset and severity. Different genome-wide association and candidate gene studies have shown the role of several genetic variants in multiple loci/genes with ethnical and geographical variations. This study was designed to detect the association of a single-nucleotide polymorphism (SNP) rs10865035 in the AFF3 gene with the genetic background of rheumatoid arthritis (RA) in the Pakistani cohort. A total of 703 individuals, including 409 RA patients and 294 healthy controls, were genotyped using TaqMan assay and Tri primer ARMS-PCR (amplification-refractory mutation system-polymerase chain reaction) methods. The association of rs10865035 with the RA was statistically determined using different models. Interestingly, besides the homozygous recessive model (G/G vs. A/G + A/A) (OR = 1.693(1.06-2.648); P = 0.025), all other models, which included the codominant (χ 2 = 5.169; P = 0.075), homozygous dominant (A/A vs. G/G + A/G) (OR = 0.867 (0.636-1.187); P = 0.41), heterozygous (A/G vs. A/A + GG) (OR = 0.491 (0.667-1.215); P = 0.49), and additive model (OR = 0.826 (0.665-1.027); P = 0.08) showed insignificant distribution of the genotypes among the cases and controls. These findings suggest that the AFF3 gene (rs10865035) has no significant role in the onset of RA in the Pakistani population.

Rheumatic diseases in Africa

Historically, rheumatic diseases have not received much attention in Africa, particularly in sub-Saharan Africa, possibly owing to a focus on the overwhelming incidence of infectious diseases and the decreased life span of the general population in this region. Global attention and support, together with better health policies and planning, have improved outcomes for many infectious diseases; thus, increasing attention is being turned to chronic non-communicable diseases. Rheumatic diseases were previously considered to be rare among Africans but there is now a growing interest in these conditions, particularly as the number of rheumatologists on the continent increases. This interest has resulted in a growing number of publications from Africa on the more commonly encountered rheumatic diseases, as well as case reports of rare diseases. Despite the limited amount of available data, some aspects of the epidemiology, genetics and clinical and laboratory features of rheumatic diseases in African populations are known, as is some detail on the use of therapeutics. Similarities and differences in these conditions can be seen across the multi-ethnic and genetically diverse African continent, and it is hoped that increased awareness of rheumatic diseases in Africa will lead to earlier diagnosis and better outcomes for patients.

The prevalence of rheumatic diseases is increasing in African countries, leading to an increased need for specialist rheumatologists and disease-modifying drugs. In this Review, the authors outline what is currently known about the state of rheumatic diseases in Africa.

In the past, there has been an emphasis on communicable diseases in Africa, but attention has now shifted towards non-communicable diseases such as rheumatic diseases.

Common rheumatic diseases are seen in Africa and are both comparable and different from presentations seen outside of Africa.

Diverse genetic and environmental factors affect the presentation of common rheumatic diseases among different African nations.

A shortage of appropriately trained staff, laboratory testing capacity and effective medications exists across the whole continent.

Advocacy and research are needed to increase awareness of the risk factors, presentations and management of rheumatic diseases in Africa.

Specialized treatment guidelines are needed for resource-poor countries in Africa.

Efficacy of Allogeneic Hematopoietic Cell Transplantation for Autoimmune Diseases

Allogeneic hematopoietic cell transplantation (HCT) may be efficacious for autoimmune diseases (AIDs), but its efficacy for individual AIDs is unknown. Factors influencing the likelihood of relapse for each AID are also unknown. This study aimed to determine the likelihood of relapse for each common AID and to generate hypotheses about factors influencing the likelihood of relapse. We reviewed charts of adult patients with nonhematologic AIDs who had undergone HCT in Alberta (n = 21) and patients described in the literature (n = 67). We used stringent inclusion criteria to minimize the inclusion of patients whose AID may have been cured before transplantation. We also used stringent definitions of AID relapse and remission. AID relapsed in 2 of 9 patients (22%) with lupus, in 4 of 12 (33%) with rheumatoid arthritis (RA), in 0 of 4 (0%) with systemic sclerosis (SSc), in 3 of 16 (19%) with psoriasis, in 1 of 12 (8%) with Behçet's disease (BD), in 1 of 15 (7%) with Crohn's disease (CD), in 0 of 5 (0%) with ulcerative colitis (UC), in 4 of 8 (50%) with multiple sclerosis (MS), and in 3 of 3 (100%) with type 1 diabetes mellitus (T1DM). Among highly informative patients (followed for >1 year after discontinuation of immunosuppressive therapy if no relapse, or donor AID status known if relapse), relapse occurred in 0 of 3 patients with lupus, in 2 of 7 with RA, in 0 of 2 with SSc, in 3 of 6 with psoriasis, in 0 of 3 with BD, in 0 of 10 with CD, in 0 of 3 with UC, in 2 of 3 with MS, and in 2 of 2 with T1DM. There appeared to be no associations between AID relapse and low intensity of pretransplantation chemoradiotherapy, multiple lines of AID therapy (surrogate for AID refractoriness) except perhaps for lupus, absence of serotherapy for graft-versus-host disease (GVHD) prophylaxis, lack of GVHD except perhaps for lupus, or incomplete donor chimerism. Even though remission commonly occurs after HCT in lupus, RA, SSc, psoriasis, BD, CD, and UC, HCT is efficacious for only a subset of patients. The efficacy appears to be unrelated to pretransplantation therapy, GVHD, or chimerism. Large studies are needed to determine the characteristics of patients likely to benefit from HCT for each AID.

Sexual Dimorphism in the Expression of Pain Phenotype in Preclinical Models of Rheumatoid Arthritis

Rheumatoid arthritis is one of most frequent rheumatic diseases, affecting around 1% of the population worldwide. Pain impacting the quality of life for the patient with rheumatoid arthritis, is often the primary factor leading them to seek medical care. Although sex-related differences in humans and animal models of rheumatoid arthritis are described, the correlation between pain and sex in rheumatoid arthritis has only recently been directly examined. Here we review the literature and explore the mechanisms underlying the expression of the pain phenotype in females and males in preclinical models of rheumatoid arthritis.

Multipotent Mesenchymal Stromal Cells in Rheumatoid Arthritis and Systemic Lupus Erythematosus; From a Leading Role in Pathogenesis to Potential Therapeutic Saviors?

The pathogenesis of the autoimmune rheumatological diseases including rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) is complex with the involvement of several immune cell populations spanning both innate and adaptive immunity including different T-lymphocyte subsets and monocyte/macrophage lineage cells. Despite therapeutic advances in RA and SLE, some patients have persistent and stubbornly refractory disease. Herein, we discuss stromal cells' dual role, including multipotent mesenchymal stromal cells (MSCs) also used to be known as mesenchymal stem cells as potential protagonists in RA and SLE pathology and as potential therapeutic vehicles. Joint MSCs from different niches may exhibit prominent pro-inflammatory effects in experimental RA models directly contributing to cartilage damage. These stromal cells may also be key regulators of the immune system in SLE. Despite these pro-inflammatory roles, MSCs may be immunomodulatory and have potential therapeutic value to modulate immune responses favorably in these autoimmune conditions. In this review, the complex role and interactions between MSCs and the haematopoietically derived immune cells in RA and SLE are discussed. The harnessing of MSC immunomodulatory effects by contact-dependent and independent mechanisms, including MSC secretome and extracellular vesicles, is discussed in relation to RA and SLE considering the stromal immune microenvironment in the diseased joints. Data from translational studies employing MSC infusion therapy against inflammation in other settings are contextualized relative to the rheumatological setting. Although safety and proof of concept studies exist in RA and SLE supporting experimental and laboratory data, robust phase 3 clinical trial data in therapy-resistant RA and SLE is still lacking.

Identification of differentially expressed genes, signaling pathways and immune infiltration in rheumatoid arthritis by integrated bioinformatics analysis

Background

The disability rate associated with rheumatoid arthritis (RA) ranks high among inflammatory joint diseases. However, the cause and potential molecular events are as yet not clear. Here, we aimed to identify differentially expressed genes (DEGs), pathways and immune infiltration involved in RA utilizing integrated bioinformatics analysis and investigating potential molecular mechanisms.

Materials and methods

The expression profiles of GSE55235, GSE55457, GSE55584 and GSE77298 were downloaded from the Gene Expression Omnibus database, which contained 76 synovial membrane samples, including 49 RA samples and 27 normal controls. The microarray datasets were consolidated and DEGs were acquired and further analyzed by bioinformatics techniques. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of DEGs were performed using R (version 3.6.1) software, respectively. The protein-protein interaction (PPI) network of DEGs were developed utilizing the STRING database. Finally, the CIBERSORT was used to evaluate the infiltration of immune cells in RA.

Results

A total of 828 DEGs were recognized, with 758 up-regulated and 70 down-regulated. GO and KEGG pathway analyses demonstrated that these DEGs focused primarily on cytokine receptor activity and relevant signaling pathways. The 30 most firmly related genes among DEGs were identified from the PPI network. The principal component analysis showed that there was a significant difference between the two tissues in infiltration immune.

Conclusion

This study shows that screening for DEGs, pathways and immune infiltration utilizing integrated bioinformatics analyses could aid in the comprehension of the molecular mechanisms involved in RA development. Besides, our study provides valuable data related to DEGs, pathways and immune infiltration of RA and may provide new insight into the understanding of molecular mechanisms.

Serum CRP, MDA, Vitamin C, and Trace Elements in Bangladeshi Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disorder that is a painful health crisis. This study aimed to assess the serum C-reactive protein (CRP), malondialdehyde (MDA), non-enzymatic antioxidant (vitamin C), and trace elements (Zn, Cu, Mn, and Fe) in RA patients, and thereby correlate these parameters with the association of RA. This study included 20 Bangladeshi RA patients and 20 normal healthy volunteers as control subjects. CRP level was determined using a laboratory-based latex agglutination-enhanced immunoassay. The lipid peroxidation level was determined by measurement of the serum level of MDA. Non-enzymatic antioxidant vitamin C was assessed by UV spectrophotometric method. Trace elements were determined by atomic absorption spectroscopy (AAS). Our study observed significantly higher concentrations of CRP (p < 0.001) and MDA (p < 0.001), and significantly lower concentrations of vitamin C (p < 0.001) in the RA patient. The mean values of Zn, Cu, Mn, and Fe were 6.62 ± 0.34, 1.42 ± 0.17, 7.51 ± 0.23, and 29.25 ± 0.41 ppm for the RA patients respectively and 13.57 ± 9.13, 1.15 ± 0.17, 1.59 ± 0.18, and 62.47 ± 5.25 ppm for the control subjects, consequently. There was a significant difference (p < 0.05) in the trace element levels between the RA patients and control subjects. Our study suggests that a higher concentration of CRP and MDA, lower levels of vitamin C, and altered trace elements may be linked to RA.

Adult-Onset Anti-Citrullinated Peptide Antibody-Negative Destructive Rheumatoid Arthritis Is Characterized by a Disease-Specific CD8+ T Lymphocyte Signature

Rheumatoid arthritis (RA) is a complex autoimmune disease targeting synovial joints. Traditionally, RA is divided into seropositive (SP) and seronegative (SN) disease forms, the latter consisting of an array of unrelated diseases with joint involvement. Recently, we described a severe form of SN-RA that associates with characteristic joint destruction. Here, we sought biological characteristics to differentiate this rare but aggressive anti-citrullinated peptide antibody-negative destructive RA (CND-RA) from early seropositive (SP-RA) and seronegative rheumatoid arthritis (SN-RA). We also aimed to study cytotoxic CD8+ lymphocytes in autoimmune arthritis. CND-RA, SP-RA and SN-RA were compared to healthy controls to reveal differences in T-cell receptor beta (TCRβ) repertoire, cytokine levels and autoantibody repertoires. Whole-exome sequencing (WES) followed by single-cell RNA-sequencing (sc-RNA-seq) was performed to study somatic mutations in a clonally expanded CD8+ lymphocyte population in an index patient. A unique TCRβ signature was detected in CND-RA patients. In addition, CND-RA patients expressed higher levels of the bone destruction-associated TNFSF14 cytokine. Blood IgG repertoire from CND-RA patients recognized fewer endogenous proteins than SP-RA patients’ repertoires. Using WES, we detected a stable mutation profile in the clonally expanded CD8+ T-cell population characterized by cytotoxic gene expression signature discovered by sc-RNA-sequencing. Our results identify CND-RA as an independent RA subset and reveal a CND-RA specific TCR signature in the CD8+ lymphocytes. Improved classification of seronegative RA patients underlines the heterogeneity of RA and also, facilitates development of improved therapeutic options for the treatment resistant patients.

Associations between Polymorphisms in the IL-1 Gene and the Risk of Rheumatoid Arthritis and Systemic Lupus Erythematosus: Evidence from a Meta-Analysis

BACKGROUND

Previous studies on polymorphisms in interleukin-1 (IL-1) and the risk of rheumatoid arthritis (RA)/systemic lupus erythematosus (SLE) yielded inconsistent results.

OBJECTIVES

The authors performed this meta-analysis to more robustly evaluate associations between polymorphisms in the IL-1 gene and the risk of RA/SLE.

METHODS

MEDLINE, Embase, Web of Science, Wanfang, VIP, and CNKI were systematically searched for eligible studies, and 34 relevant studies were finally selected to be eligible for inclusion.

RESULTS

We found that IL-1A +4845G/T polymorphism was significantly associated with the risk of RA in the overall population (dominant comparison: p = 0.02; overdominant comparison: p = 0.05; allele comparison: p = 0.04), whereas IL-1B +3954C/T polymorphism was significantly associated with the risk of RA in the overall population (overdominant comparison: p = 0.03; allele comparison: p = 0.01) and Asians (recessive comparison: p = 0.007; allele comparison: p = 0.002). In addition, we found that IL-1A -889C/T polymorphism was significantly associated with the risk of SLE in Caucasians (allele comparison: p = 0.04), IL-1B -31T/C polymorphism was significantly associated with the risk of SLE in the overall population (recessive comparison: p = 0.04), and IL-1B -511C/T polymorphism was significantly associated with the risk of SLE in Asians (recessive comparison: p = 0.01; allele comparison: p = 0.03).

CONCLUSIONS

This meta-analysis suggests that IL-1A +4845G/T and IL-1B +3954C/T polymorphisms may influence the risk of RA, whereas IL-1A -889C/T, IL-1B -31T/C, and IL-1B -511C/T polymorphisms may influence the risk of SLE.

Characterisation of CD4+ T-cell subtypes using single cell RNA sequencing and the impact of cell number and sequencing depth

CD4+ T-cells represent a heterogeneous collection of specialised sub-types and are a key cell type in the pathogenesis of many diseases due to their role in the adaptive immune system. By investigating CD4+ T-cells at the single cell level, using RNA sequencing (scRNA-seq), there is the potential to identify specific cell states driving disease or treatment response. However, the impact of sequencing depth and cell numbers, two important factors in scRNA-seq, has not been determined for a complex cell population such as CD4+ T-cells. We therefore generated a high depth, high cell number dataset to determine the effect of reduced sequencing depth and cell number on the ability to accurately identify CD4+ T-cell subtypes. Furthermore, we investigated T-cell signatures under resting and stimulated conditions to assess cluster specific effects of stimulation. We found that firstly, cell number has a much more profound effect than sequencing depth on the ability to classify cells; secondly, this effect is greater when cells are unstimulated and finally, resting and stimulated samples can be combined to leverage additional power whilst still allowing differences between samples to be observed. While based on one individual, these results could inform future scRNA-seq studies to ensure the most efficient experimental design.

Targeted and Combined TPCA-1-Gold Nanocage Therapy for In Vivo Treatment of Inflammatory Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that is currently incurable. Inhibition of inflammation can prevent the deterioration of RA. 2-[(Aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide (TPCA-1) suppresses inflammation via the inhibition of nuclear factor-κ (NF-κB) signaling pathway. Gold-based therapies have been used to treat inflammatory arthritis since the 1940s. Hyaluronic acid (HA) is a targeting ligand for CD44 receptors overexpressed on activated macrophages. Therefore, a combined therapy based on TPCA-1, gold, and HA was explored for the treatment of RA in this study. We used gold nanocages (AuNCs) to load TPCA-1 and modified the TPCA-1 (T) loaded AuNCs with HA and peptides (P) to construct an anti-inflammatory nanoparticle (HA-AuNCs/T/P). An adjuvant-induced arthritis (AIA) mice model was used to investigate the in vivo anti-inflammatory efficacy of HA-AuNCs/T/P. In vivo distribution results showed that HA-AuNCs/T/P had increased and prolonged accumulation at the inflamed paws of AIA mice. Treatment by the HA-AuNCs/T/P suppressed joint swelling and alleviated cartilage and bone damage. By loading to HA-AuNCs/T/P, the effective concentration of TPCA-1 was greatly reduced from 20 to 0.016 mg/kg mice. This study demonstrated that HA-AuNCs/T/P could effectively suppress inflammation and alleviate the symptoms of AIA mice, suggesting a great potential of HA-AuNCs/T/P for the treatment of RA.