Persistent inflammatory and non-inflammatory mechanisms in refractory rheumatoid arthritis

Extracellular vesicle as a next-generation drug delivery platform for rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a systemic autoimmune disorder characterized by chronic inflammation and progressive damage to connective tissue. It is driven by dysregulated cellular homeostasis, often leading to autoimmune destruction and permanent disability in severe cases. Over the past decade, various drug delivery systems have been developed to enable targeted therapies for disease prevention, reduction, or suppression. As an emerging therapeutic platform, extracellular vesicles (EVs) offer several advantages over conventional drug delivery systems, including biocompatibility and low immunogenicity. Consequently, an increasing number of studies have explored EV-based delivery systems in the treatment of RA, leveraging their natural ability to evade phagocytosis, prolong in vivo half-life, and minimize the immunogenicity of therapeutic agents. In this review, we first provide an in-depth overview of the pathogenesis of RA and the current treatment landscape. We then discuss the classification and biological properties of EVs, their potential therapeutic mechanisms, and the latest advancements in EVs as drug delivery platforms for RA therapy. We emphasize the significance of EVs as carriers in RA treatment and their potential to revolutionize therapeutic strategies. Furthermore, we examine key technological innovations and the future trajectory of EV research, focusing on the challenges and opportunities in translating these platforms into clinical practice. Our discussion aims to offer a comprehensive understanding of the current state and future prospects of EV-based therapeutics in RA.

Acidosis regulates immune progression in rheumatoid arthritis by promoting the expression of cytokines and co-stimulatory molecules in synovial fibroblasts

BACKGROUND

Tissue acidosis is a key characteristic of RA. It remains unclear whether acidosis promotes the formation of the complex adaptive immune landscape mainly characterized by T cell activation in RA by influencing synovial fibroblasts. This study aims to investigate the influence of acidosis on the immune microenvironment of RA by exploring the cytokine secretion and expression of co-stimulatory factors of RA synovial fibroblasts.

METHODS

The Bulk RNA-seq dataset (GSE89408, Normal = 23, RA = 150) was utilized for cytokine screening and the immune state assessment based on disease stage. RNA-seq was employed to investigate cytokine and co-stimulatory molecule expression following 6 h of acid stimulation, combined with Bulk RNA-seq data to evaluate contributions to RA. Human cytokine arrays were used to confirm cytokine accumulation in supernatants after 12 h of acid stimulation. Proteomics was applied to explore cellular functional states in RASFs under 6 h of acid stress, with joint RNA-seq analysis elucidating transcription factor activation. Validation of select high-throughput data was performed using qRT-PCR and immune-based assays.

RESULTS

Bulk RNA-seq and RNA-seq identified 56 differentially expressed cytokines at their intersection. Functional enrichment analysis demonstrated that acid stimulation enhanced cytokine secretion and T cell chemotaxis in RA synovial fibroblasts (RASFs). Cytokine array revealed that acid exposure increased the accumulation of growth factors (e.g., FGF, VEGF) by over twofold and promoted the expression of multiple inflammatory and chemotactic factors. Immune state analysis indicated that acid stimulation induced a complex immune landscape by upregulating co-stimulatory and antigen-presenting molecules. Proteomics showed that acid stress enhanced mitochondrial function and triggered metabolic reprogramming in RASFs. Integrated transcriptomic and proteomic analyses revealed that AP1 regulates gene expression in RASFs, with its activation further confirmed by Western blotting and immunofluorescence.

Delineating inflammatory from non-inflammatory mechanisms for therapy optimization in psoriatic arthritis

Psoriatic arthritis (PsA) is anatomically much more heterogeneous than rheumatoid arthritis, as, beyond synovitis, it often also involves enthesitis, peritendinitis, tenosynovitis, osteitis and periostitis. This heterogeneity currently precludes a gold standard for objectively defining resolution of inflammation following treatment, with enthesitis posing a particular challenge. Despite these difficulties, we apply lessons learned from rheumatoid arthritis to describe how patients with PsA and an inadequate response to therapy can be designated within two patient subgroups, characterized by persistent inflammatory PsA (PIPsA) and non-inflammatory PsA (NIPsA), respectively. The NIPsA phenotype is defined by the lack of ongoing joint inflammation, as confirmed through clinical assessment and imaging, along with normalized inflammatory marker levels. NIPsA might be associated with obesity, biomechanical-related pain, osteoarthritis, fibromyalgia, secondary post-inflammatory damage and central pain mechanisms. In this article, we frame PsA composite outcomes measures in relationship to the PIPsA and NIPsA phenotypes and propose that this approach might help to minimize unnecessary or ineffective cycling of PsA therapy in patients who acquire dominant non-inflammatory mechanisms and might also inform future trial design.

Antibody-Nanoparticle Conjugates in Therapy: Combining the Best of Two Worlds

Monoclonal antibodies (mAbs) and antibody fragments have revolutionized medicine as highly specific binding agents and inhibitors. At the same time, several types of nanomaterials, including liposomes, lipid nanoparticles (NPs), polymersomes, metal and metal oxide NPs, and protein nanostructures, are increasingly utilized and explored for therapeutic potential due to their versatility, chemical and physical properties, and tunability. However, nanomaterials alone often lack specificity, leading to relatively low efficacy and/or high toxicity. To address this problem, a rapidly emerging area is antibody-nanomaterial conjugates (ANCs), which combine the precise targeting specificity of antibodies with the effector functionality of the nanomaterial. In this review, we give a brief introduction to mAbs and major conjugation techniques, describe major classes of nanomaterials being studied for therapeutic potential, and review the literature on ANCs of each class. Special focus is given to emerging applications including ANCs addressing the blood-brain barrier, ANCs delivering nucleic acids, and light-activated ANCs. While many disease targets are related to cancer, ANCs are also under development to address autoimmune, neurological, and infectious diseases. While important challenges remain, ANCs are poised to become a next-generation therapeutic technology.

Early rheumatoid arthritis, two distinctive structural damage patterns revealed by MRI: an 8-year longitudinal study

OBJECTIVE

To determine how inflammatory and structural parameters change long-term on standard treatment in rheumatoid arthritis patients and which baseline parameter best predicts long-term structural damage.

MATERIAL AND METHODS

Prospective study of early rheumatoid arthritis (ERA) patients (symptom duration ≤ 24 months) who underwent identical clinical, serological, radiographic, and dynamic contrast-enhanced MRI of the wrist assessments at baseline, year-1, and year-8. MR images were analyzed semi-quantitatively (Rheumatoid Arthritis Magnetic Resonance Imaging Score [RAMRIS]) and quantitatively (synovial volume (cm3); synovial perfusion; bone marrow edema (BME) proportion [%]). Multivariate analyses and receiver operating curves were applied to find the best predictor of long-term structural damage.

RESULTS

81 patients (61 ± 12 years, F/M:67/14) were studied. MRI-detected inflammatory parameters markedly improved from baseline to year-1 and slightly deteriorated from year-1 to year-8 (synovial volume:6.7 ± 5.0→2.6 ± 2.9→3.6 ± 3.3 cm3 (p < 0.01); BME proportion:13.1 ± 9.3→7.4 ± 5.0→9.2 ± 9.7% [p < 0.01]). Structural damage progressively deteriorated from baseline to year-8. Two long-term structural damage pattern groups were apparent, namely a "non-progressive structural damage pattern" (62%, 50/81) and a "progressive structural damage pattern" (38%, 31/81). Functional impairment was more frequent and more severe at year-8 in patients with progressive structural damage. MRI-detected bone erosion score better predicted (AUC = 0.81, CI: 0.71-0.91) year-8 structural damage than clinical (SDAI AUC = 0.61, CI: 0.48-0.74), serological (CRP AUC = 0.60, CI: 0.47-0.73), or radiographic (AUC = 0.59, CI: 0.45-0.72) assessment.

CONCLUSION

In ERA patients, two distinct structural damage patterns are evident. Baseline bone erosion score is better than clinical, serological, or radiographic assessment at predicting long-term structural damage.

KEY POINTS

Questions The value of MRI in predicting long-term structural damage in ERA patients is not clear. Findings This study identified two distinct long-term structural damage progression patterns of ERA patients. MRI can better differentiate between these two groups at baseline than clinical, serological, or radiographic assessment. Clinical relevance MRI examination should be performed in all ERA patients at baseline to determine their structural damage pattern. This will allow a better prediction of patient outcomes in the long-term.

Single cell immunoprofile of synovial fluid in rheumatoid arthritis with TNF/JAK inhibitor treatment

Numerous patients with rheumatoid arthritis (RA) manifest severe syndromes, including elevated synovial fluid volumes (SF) with abundant immune cells, which can be controlled by TNF/JAK inhibitors. Here, we apply single-cell RNA sequencing (scRNA-seq) and subsequent validations in SF from RA patients. These analyses of synovial tissue show reduced density of SF-derived pathogenic cells (e.g., SPP1+ macrophages and CXCL13+CD4+ T cells), altered gene expression (e.g., SPP1 and STAT1), molecular pathway changes (e.g., JAK/STAT), and cell-cell communications in drug-specific manners in samples from patients pre-/post-treated with adalimumab/tofacitinib. Particularly, SPP1+ macrophages exhibit pronounced communication with CXCL13+CD4+ T cells, which are abolished after treatment and correlate with treatment efficacy. These pathogenic cell types alone or in combination can augment inflammation of fibroblast-like synoviocytes in vitro, while conditional Spp1 knocking-out reduces RA-related cytokine expression in collagen-induced arthritis mice models. Our study shows the functional role of SF-derived pathogenic cells in progression and drug-specific treatment outcomes in RA.

Prevalence and characteristics of adults with difficult-to-treat rheumatoid arthritis in a large patient registry

OBJECTIVES

An estimated 5-20% of patients with rheumatoid arthritis (RA) fail multiple treatments and are considered 'difficult-to-treat' (D2T), posing a substantial clinical challenge for rheumatologists. A European League Against Rheumatism (EULAR) task force proposed a definition of D2T-RA in 2021. We applied EULAR's D2T definition in a cohort of patients with established RA to assess prevalence, and we compared clinical characteristics of participants with D2T-RA with matched comparisons.

METHODS

Data from the longitudinal Brigham and Women's Hospital Rheumatoid Arthritis Sequential Study (BRASS) registry were used. Participants were classified as D2T if they met EULAR's definition. A comparison group of non-D2T-RA patients were matched 2:1 to every D2T patient, and differences in characteristics were evaluated in descriptive analyses. Prevalence rates of D2T were estimated using Poisson regression.

RESULTS

We estimated the prevalence of D2T-RA to be 14.4 (95% CI: 12.8, 16.3) per 100 persons among 1581 participants with RA, and 22.3 (95% CI: 19.9, 25.0) per 100 persons among 1021 who were biologic/targeted synthetic DMARD experienced. We observed several differences in demographics, comorbidities and RA disease activity between D2T-RA and non-D2T-RA comparisons. Varying EULAR sub-criteria among all participants in BRASS resulted in a range of D2T-RA prevalence rates, from 0.6 to 17.5 per 100 persons.

CONCLUSION

EULAR's proposed definition of D2T-RA identifies patients with RA who have not achieved treatment targets. Future research should explore heterogeneity in these patients and evaluate outcomes to inform the design of future studies aimed at developing more effective RA management protocols.

Quantum Health Accelerator® Ameliorates CFA-Induced Animal Model of Rheumatoid Arthritis: Investigating the Role of Immunomodulatory and Anti-Oxidative Effects

Introduction: Rheumatoid arthritis (RA) is a systemic inflammatory and autoimmune disease characterized by joint swelling, pain, damage to the cartilage, and disability. In the present study, we aimed to evaluate the anti-oxidant, anti-inflammatory, and immune-modulatory properties of Quantum Health Accelerator® as water enriched with vital bio-quantum information/energy (EW) following complete Freund's adjuvant (CFA)-induced RA in rats. Methods: Forty adult male Wistar rats (180-220 g) were divided into five groups. Arthritis was induced on day one using a single subcutaneous injection of CFA into the left hind footpad of the rat. Rats were assigned to receive methotrexate (MTX, 2 mg/kg/week, intraperitoneally), EW (orally, instead of normal water ad libitum), or their combination for 29 days. The anti-RA activities were determined by paw edema, joint diameter, arthritis score, and several nociceptive behavioral tests (thermal hyperalgesia, cold allodynia, and tactile allodynia). The levels of inflammatory (TNF-α, CRP, RF, and anti-CCP), anti-inflammatory (IL-10), and oxidative stress (NO, MDA, and GSH) markers were measured in serum. In addition, the levels of IFN-γ, IL-4, IL-17, and TGF-β were assessed in the spleen-isolated lymphocytes. Results: We found that treatment with MTX, EW, and their combination remarkably ameliorated thermal hyperalgesia, cold allodynia, and tactile allodynia results following CFA-induced RA in rats. In addition, EW also notably attenuated arthritis score, joint diameter, inflammatory cytokines, and oxidative markers while propagating anti-inflammatory and anti-oxidative mediators. Conclusions: We reveal that EW possesses anti-arthritic effects, possibly through anti-oxidative, anti-inflammatory, and immunomodulatory properties. Collectively, EW may be a promising therapeutic agent for treating RA.

Efficacy and safety of Janus kinase inhibitors in patients with difficult-to-treat rheumatoid arthritis

OBJECTIVES

This study evaluated the effectiveness of Janus kinase inhibitors (JAKi) in patients with difficult-to-treat rheumatoid arthritis (D2T RA).

METHODS

This study included 220 patients with RA who were treated with JAKi. Sixty-two patients were naïve to biological disease-modifying antirheumatic drugs (bDMARDs)/JAKi (1st group), 57 patients were failure to one bDMARDs/JAKi (2nd group), and 101 patients were failure to ≥ 2 bDMARDs/JAKi. Of these 101 patients, 25 did not meet the D2T RA criteria (non-D2T RA group) and 76 met the D2T RA criteria (D2T RA group).

RESULTS

: DAS28-ESR was improved in all groups at 24 weeks (1st: P < .01, 2nd: P < .01, non-D2T RA: P = .01, D2TRA: P = .02), and improvement ratio of DAS28-ESR was not different between DT2RA group and 2nd (P = .73) or non-D2T RA group (P = .68). Glucocorticoid use [odds ratios: 8.67; 95% confidence interval (CI): 1.23-60.90; P = .03] and number of past bDMARD/JAKi uses ≥ 3 (odds ratios: 10.55; 95% CI: 1.39-80.30; P = .02) were risk factors for DAS28-ESR ≥ 3.2 at 24 weeks in the D2T RA group.

CONCLUSIONS

Clinical efficacy of JAKi in D2T RA group did not differ from that in 2nd and non-D2T RA groups. Glucocorticoid use and multiple bDMARD/JAKi failure were poor prognostic factors for D2T RA.

ITGA5+ synovial fibroblasts orchestrate proinflammatory niche formation by remodelling the local immune microenvironment in rheumatoid arthritis

OBJECTIVES

To investigate the phenotypic heterogeneity of tissue-resident synovial fibroblasts and their role in inflammatory response in rheumatoid arthritis (RA).

METHODS

We used single-cell and spatial transcriptomics to profile synovial cells and spatial gene expressions of synovial tissues to identify phenotypic changes in patients with osteoarthritis, RA in sustained remission and active state. Immunohistology, multiplex immunofluorescence and flow cytometry were used to identify synovial fibroblasts subsets. Deconvolution methods further validated our findings in two cohorts (PEAC and R4RA) with treatment response. Cell coculture was used to access the potential cell-cell interactions. Adoptive transfer of synovial cells in collagen-induced arthritis (CIA) mice and bulk RNA sequencing of synovial joints further validate the cellular functions.

RESULTS

We identified a novel tissue-remodelling CD45-CD31-PDPN+ITGA5+ synovial fibroblast population with unique transcriptome of POSTN, COL3A1, CCL5 and TGFB1, and enriched in immunoregulatory pathways. This subset was upregulated in active and lympho-myeloid type of RA, associated with an increased risk of multidrug resistance. Transforming growth factor (TGF)-β1 might participate in the differentiation of this subset. Moreover, ITGA5+ synovial fibroblasts might occur in early stage of inflammation and induce the differentiation of CXCL13hiPD-1hi peripheral helper T cells (TPHs) from naïve CD4+ T cells, by secreting TGF-β1. Intra-articular injection of ITGA5+ synovial fibroblasts exacerbates RA development and upregulates TPHs in CIA mice.

CONCLUSIONS

We demonstrate that ITGA5+ synovial fibroblasts might regulate the RA progression by inducing the differentiation of CXCL13hiPD-1hi TPHs and remodelling the proinflammatory microenvironments. Therapeutic modulation of this subpopulation could therefore be a potential treatment strategy for RA.

Natural product extract fractions as potential arthritis treatments: A detailed analysis using in-silico, in-vivo, and in-vitro methods

Two characteristics of the systemic autoimmune disease rheumatoid arthritis (RA) include extra-articular involvement and inflammatory arthritis. It is a long-term inflammatory condition that mostly affects the synovial joints and is often triggered by a confluence of environmental factors, including tobacco use, and genetics. The review investigates natural products' role in arthritis through three key approaches. In-silico analysis identifies molecular mechanisms and targets of these products, revealing their potential for therapeutic use. In-vivo studies evaluate how well these products work and their safety in reducing joint inflammation. In-vitro studies focus on how these compounds interact at the cellular level and their effects on signaling pathways. Together, these approaches offer a comprehensive understanding of how natural products could benefit arthritis management. This review focuses on translational studies and highlights the possible role of natural compounds as adjunctive therapies to conventional arthritis treatments. In conclusion, this study indicates that natural products have potential advantages in treating osteoarthritis and rheumatoid arthritis based on in-silico analysis which shows anti-inflammatory effects, in-vivo studies that reduce joint inflammation, and in-vitro studies that amplify arthritis management. To improve the therapeutic advantages of natural products utilized for treating arthritis, an all-inclusive examination has been done to give direction for the following research efforts.

Obesity and fibromyalgia are associated with Difficult-to-Treat Rheumatoid Arthritis (D2T-RA) independent of age and gender

BACKGROUND

There is still a significant proportion of patients with rheumatoid arthritis (RA) in whom multiple therapeutic lines are ineffective. These cases are defined by the EULAR criteria as Difficult-to-Treat RA (D2T-RA) for which there is limited knowledge of predisposing factors.

OBJECTIVE

To identify the clinical features associated with D2T-RA in real-life practice.

METHODS

We retrospectively collected demographic, clinical, and serological data on 458 patients consecutively seen for RA between January 2019 and January 2023. We compared patients fulfilling the D2T-RA criteria with the remaining RA cohort using univariate comparisons and logistic regression to determine the impact of clinical features, comorbidities on outcome variable, adjusted for confounders.

RESULTS

Seventy-one/458 (16%) patients fulfilled the 2021 EULAR criteria for D2T-RA with no significant differences for age (median 62 years interquartile range -IQR- 58- 65 vs. 62 IQR 60 - 63 in non-D2T), gender prevalence (23% in both groups) and positivity rates for rheumatoid factors (62% vs. 62% in non-D2T) and Anti-Citrullinated Protein Antibodies (ACPA) (69% vs. 61% in non-D2T). Conversely, D2T-RA cases had significant longer disease duration (median 15 years IQR 13-17 vs. 10 years IQR 9-11 in non-D2T; p < 0.0001). D2T-RA also had more erosions at baseline (24% vs. 11% in non-D2T; p < 0.0001) and higher disease activity index (CDAI) at the last follow up visit (15.7 ± 10.5 vs. 7.5 ± 8.8 in non-D2T; p < 0.0001). D2T-RA cases suffered with higher frequency of obesity (33% vs. 19% in non-D2T, p = 0.021) and fibromyalgia (25% vs. 10% in non-D2T, p < 0.0001). The multivariate analysis confirmed the correlations of D2T-RA with disease duration (Odds ratio -OR- 1.06, 95% confidence interval -CI-1.03-1.09; p < 0.0001), baseline erosions (OR 2.73, 95% CI 1.28-5.82; p = 0.009), obesity (OR 2.22, 95% CI 1.10-4.50; p = 0.026) and fibromyalgia (OR 3.91, 95% CI 1.76-8.70; p = 0.001), independent of age and gender.

CONCLUSIONS

High disease activity, baseline erosions and disease duration are significantly associated with the D2T phenotype of RA while we confirm the importance of obesity and fibromyalgia.

Recent Advances in Drug Delivery Approaches for Rheumatoid Arthritis

Morbidity, disability, and healthcare expenses associated with rheumatoid arthritis (RA) impose a considerable health and economical burden on both patients and healthcare systems. This review aimed to examine the pathophysiological aspects of RA that may help design different types of drugs and drug delivery systems. These include monoclonal antibodies, immunoglobulins, tiny chemicals, and transgenes for gene therapy. These novel nanocarrier-based therapies target the underlying biological processes involved in RA while minimizing the systemic adverse effects of drugs.

Difficult-to-treat psoriatic arthritis: refining the definition using a statistical model in a real-life cohort

Objectives

The study aims to evaluate the applicability of the D2T psoriatic arthritis (PsA) definition, adapted from rheumatoid arthritis, within a single-center observational cohort of PsA patients treated with b/tsDMARDs. In addition, we aimed to establish a numerical index defining D2T-PsA based on the ratio of observed to expected failed b/tsDMARDs and to develop a predictive model identifying features associated with the D2T condition.

Methods

The study included 267 consecutive adult PsA patients receiving b/tsDMARDs, collecting demographic, clinical, and clinimetric data. The prevalence of D2T PsA patients was assessed using a proposed definition. We then developed a predictive model to assess treatment difficulty, utilizing PsA-normalized failed b/tsDMARDs. A generalized linear model was applied to identify clinical and demographic features associated with D2T PsA, employing a bagging procedure for robust variable selection, followed by univariate and multivariable analyses.

Results

Among the 267 patients, only 8 of them (2.9%) met the proposed D2T PsA criteria. In a subset of 177 patients analyzed using the predictive model, 17.2% of them demonstrated higher treatment difficulty. Univariate analysis revealed associations between treatment difficulty and female sex, psoriasis pattern, fibromyalgia, and steroid therapy. Multivariate analysis confirmed significant associations between fibromyalgia, nail and pustular psoriasis, and steroid use.

Conclusion

According to the predictive model, the proposed D2T PsA definition identified a small subset of patients with increased treatment difficulty. These findings highlight the need for refining the criteria to better define D2T PsA patients, providing valuable insights into managing complex treatment challenges in PsA.

Unmet Needs and Current Challenges of Rheumatoid Arthritis: Difficult-to-Treat Rheumatoid Arthritis and Late-Onset Rheumatoid Arthritis

Despite remarkable advances in the management of RA, there are still unmet needs that rheumatologists need to address. In this review, we focused on difficult-to-treat RA (D2T RA) and late-onset RA (LORA), and summarized their characteristics and management. The prevalence of D2T RA is reported to be 6-28% and many factors have been identified as risk factors for D2T RA, including female sex, long disease duration, seropositivity for rheumatoid factor and anti-cyclic citrullinated peptide antibody and their high titer, baseline high disease activity, and comorbidities. D2T RA is broadly divided into inflammatory and non-inflammatory conditions, and clinical features differ according to background. A proportion of D2T RA can be managed with treatment modification, mainly with interleukin-6 receptor inhibitors or Janus kinase inhibitors, but some D2T RA patients have a poor prognosis; thus, the implementation of precision medicine by stratifying patients according to disease status is needed. In the aging society, the epidemiology of RA is changing and the prevalence of LORA is increasing worldwide. LORA has distinct clinical features compared with young-onset RA, such as acute onset, low seropositivity, and high inflammation. The pathogenesis of LORA remains to be elucidated, but proinflammatory cytokines, including interleukin-6, have been reported to be significantly elevated. LORA has several management concerns other than RA itself, such as geriatric syndrome and multimorbidity. The treat-to-target strategy is effective for LORA, but the evidence is still lacking; thus, it is important to accumulate clinical and related basic data to establish the optimal treatment strategy for LORA.

Rheumatoid arthritis: a review of the key clinical features and ongoing challenges of the disease

Rheumatoid arthritis (RA) is an autoimmune inflammatory condition that primarily affects the joints and periarticular soft tissue. The development of joint swelling is traditionally regarded as the starting point of the disease. Emerging evidence indicates that RA patients often experience a preclinical stage characterized by immunological and inflammatory changes before developing the disease. The review discusses ongoing efforts to predict the transition from this preclinical phase to clinical RA and describes studies aimed at preventing the onset of RA in individuals at risk. Over the past two decades, there have been significant advancements in RA management and outcomes. An increasing number of patients can now achieve disease remission, and in some cases, this remission persists without ongoing treatment, which is effectively a cure. As new therapies and evolving scientific evidence emerge, recommendations for RA management are continuously evolving. Despite these improvements in the management of RA, many patients still do not respond to multiple conventional or more advanced therapies, including biologic and targeted synthetic disease modifying anti-rheumatic drugs, or experience disease flares when treatments are tapered or discontinued. This situation underscores the need for reliable biomarkers to guide therapy more effectively, improve personalized treatment approaches and monitoring strategies (i.e. precision medicine). In conclusion, this review provides a comprehensive overview of RA, covering new research on the 'pre-clinical' phase of the disease, as well as its epidemiology, pathogenesis, clinical manifestations, diagnosis, imaging, and management strategies. It highlights key clinical aspects of RA and addresses ongoing challenges in disease management, particularly in the areas of prevention and treatment.

Circ_0011058 alleviates RA pathology through the circ_0011058/miR-335-5p/CUL4B signal axis

Our previous study found that Cullin 4B (CUL4B) inhibited rheumatoid arthritis (RA) pathology through glycogen synthase kinase-3beta (GSK3β)/canonical Wnt signalling pathway. In this work, pre-experiment and bioinformatics analysis suggested that circ_0011058 may lead to the up-regulation of CUL4B expression by inhibiting miR-335-5p. Therefore, we studied whether circ_0011058 can promote the expression of CUL4B through sponging the miR-335-5p and further promote the pathological development of RA. Bioinformatics prediction, real-time quantitative PCR (RT-qPCR), western blot (WB), double luciferase reporter gene and other relevant methods were used to study the inhibition of circ_0011058 on RA pathology and its molecular mechanism. Results showed that the expression of circ_0011058 was significantly increased in adjuvant arthritis (AA) rats and RA fibroblast-like synoviocytes (FLS). The knockout of circ_0011058 inhibited the proliferation of AA FLS and RA FLS, decreased the levels of interleukin-1 beta (IL-1β), interleukin 6 (IL-6), interleukin 8 (IL-8), and inhibited the expression of matrix metalloproteinase 3 (MMP3), fibronectin, which showed that circ_0011058 had a strong role in promoting RA pathology. Furthermore, miR-335-5p expression was reduced in AA rats and RA FLS. The highly expressed circ_0011058 directly sponged the miR-335-5p, which led to the increase of CUL4B expression and promoted the activation of the GSK3β/canonical signalling pathway. Finally, we confirmed that miR-335-5p mediated the roles of circ_0011058 in promoting RA pathological development, which showed that the circ_0011058/miR-335-5p/CUL4B signal axis was involved in RA pathology. This work was of great significance for clarifying the roles of circ_0011058 in RA pathology, and further work was needed to establish whether circ_0011058 was a potential therapeutic target or diagnostic marker for RA.

Allogeneic bone marrow derived clonal mesenchymal stromal cells in refractory rheumatoid arthritis: a pilot study

AIMS

This phase I trial assessed the safety and potential efficacy of monthly 3 dose intravenous infusion of allogeneic bone marrow-derived clonal mesenchymal stromal cells (BM-cMSCs) in refractory rheumatoid arthritis (RA) patients over 24 weeks.

PATIENTS & METHODS

Six patients with refractory RA received BM-cMSC infusions at one-month intervals over a 24-week period. Safety outcomes included adverse events (AEs) and serious adverse events (SAEs). Clinical efficacy was assessed using the Visual Analog Scale (VAS), Simple and Clinical Disease Activity Indices (SDAI/CDAI), Health Assessment Questionnaire (HAQ), and American College of Rheumatology (ACR) response criteria. Serological makers including: erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), IL-10, IL-17, TNF-α, and Treg/Th17 ratios were measured.

RESULTS

BM-cMSC infusions were well-tolerated, with no SAEs reported. VAS scores improved in three patients, with two achieving sustained pain relief and quality-of-life enhancement. Four patients met ACR20 at week 16, while SDAI and CDAI scores indicated disease activity reduction in three patients. Anti-CCP and RF levels showed variable responses, with some increases not consistently correlating with clinical outcomes. Serological biomarkers showed mixed results; IL-10 increased in five patients, while pro-inflammatory markers TNF-α and IL-17 decreased in the same individuals.

CONCLUSIONS

BM-cMSC therapy demonstrated a favorable safety profile and potential efficacy in managing refractory RA. While preliminary results are promising, further studies with larger cohorts and long-term follow-up are needed to validate these findings and optimize therapeutic strategies.

CLINICAL TRIAL REGISTRATION

IRCT20080728001031N29.

Intermittent fasting reduces inflammation and joint damage in a murine model of rheumatoid arthritis: insights from transcriptomic and metagenomic analyses

BACKGROUND

Intermittent fasting (IF) has shown benefits in various pathological conditions. Although its anti-inflammatory potential has been recognized, its effects on the mechanism underlying rheumatoid arthritis (RA) remain insufficiently characterized. This study aimed to investigate the effects of IF in a murine model of RA.

METHODS

Collagen-induced arthritis (CIA) was developed in sixteen male DBA/1 mice, randomly assigned to two groups, with one undergoing IF every other day for four weeks. The effects of IF on joint inflammation and remodeling were evaluated clinically, histologically, and through tomography. Transcriptomic changes were characterized using expression microarrays, validated by RT-qPCR, and confirmed by immunohistochemistry. Additionally, modifications in gut microbiota were assessed through 16 S sequencing.

RESULTS

Mice subjected to IF significantly reduced the incidence and severity of clinical arthritis. Histological and radiographic assessments confirmed a decrease in inflammation and joint damage. Transcriptomic analysis revealed that IF led to the upregulation of 364 genes and the downregulation of 543 genes, with notable reductions in inflammatory signaling pathways associated with RA-related genes, including Cd72, Cd79a, Ifna, Il33, and Bglap 2. Notably, IL33 emerged as a pivotal mediator in the inflammatory processes mitigated by fasting. Key regulators associated with IF effects, such as CEBPA, FOXO1, HIF1A, PPARG, and PPARA, were identified, indicating a complex interplay between metabolic and inflammatory pathways. Furthermore, differential expression of microRNAs and lncRNAs, including miR-15b, miR-103-2, miR-302a, miR-6985, and miR- 5624, was observed. Metagenomic analysis indicated that IF enhanced the abundance and diversity of the gut microbiome, explicitly promoting anti-inflammatory bacterial populations, notably within the genus Ruminococcaceae.

CONCLUSION

Our findings suggest that IF exerts significant anti-inflammatory and immunoregulatory effects in the context of CIA. Given its non-risky nature, further investigation into the potential benefits of IF in patients with RA is warranted.

CLINICAL TRIAL NUMBER

Not applicable.

NF-κB Signaling Pathway in Rheumatoid Arthritis: Mechanisms and Therapeutic Potential

Rheumatoid arthritis (RA) is an autoimmune chronic inflammatory disease that imposes a heavy economic burden on patients and society. Bone and cartilage destruction is considered an important factor leading to RA, and inflammation, oxidative stress, and mitochondrial dysfunction are closely related to bone erosion and cartilage destruction in RA. Currently, there are limitations in the clinical treatment methods for RA, which urgently necessitates finding new effective treatments for patients. Nuclear transcription factor-κB (NF-κB) is a signaling transcription factor that is widely present in various cells. It plays an important role as a stress source in the cellular environment and regulates gene expression in processes such as immunity, inflammation, cell proliferation, and apoptosis. NF-κB has long been recognized as a pathogenic factor of RA, and its activation can exacerbate RA by promoting inflammation, oxidative stress, mitochondrial dysfunction, and bone destruction. Conversely, inhibiting the activity of the NF-κB pathway effectively inhibits these pathological processes, thereby alleviating RA. Therefore, NF-κB may be a potential therapeutic target for RA. This article describes the physiological structure of NF-κB and its important role in RA through the regulation of oxidative stress, inflammatory response, mitochondrial function, and bone destruction. Meanwhile, we also summarized the impact of NF-κB crosstalk with other signaling pathways on RA and the effect of related drugs or inhibitors targeting NF-κB on RA. The purpose of this article is to provide evidence for the role of NF-κB in RA and to emphasize its significant role in RA by elucidating the mechanisms, so as to provide a theoretical basis for targeting the NF-κB pathway as a treatment for RA.

Single-Cell Multi-Dimensional data analysis reveals the role of ARL4C in driving rheumatoid arthritis progression and Macrophage polarization dynamics

Rheumatoid arthritis (RA) is an enduring autoimmune inflammatory condition distinguished by continual joint inflammation, hyperplasia of the synovium, erosion of bone, and deterioration of cartilage.Fibroblast-like synoviocytes (FLSs) exhibiting "tumor-like" traits are central to this mechanism.ADP-ribosylation factor-like 4c (ARL4C) functions as a Ras-like small GTP-binding protein, significantly impacting tumor migration, invasion, and proliferation.However, it remains uncertain if ARL4C participates in the stimulation of RA FLSs exhibiting "tumor-like" features, thereby fostering the advancement of RA. In our investigation, we unveiled, for the inaugural instance, via the amalgamated scrutiny of single-cell RNA sequencing (scRNA-seq) and Bulk RNA sequencing (Bulk-seq) datasets, that activated fibroblast-like synoviocytes (FLSs) showcase high expression of ARL4C, and the ARL4C protein expression in FLSs derived from RA patients significantly surpasses that observed in individuals with osteoarthritis (OA) and traumatic injury (trauma).Silencing of the ARL4C gene markedly impeded the proliferation of RA FLSs by hindered the transition of cells from the G0/G1 phase to the S phase, and intensified cell apoptosis and diminished the migratory and invasive capabilities. Co-culture of ARL4C gene-silenced RA FLSs with monocytes/macrophages significantly inhibited the polarization of monocytes/macrophages toward M1 and the repolarization of M2 to M1.Furthermore, intra-articular injection of shARL4C significantly alleviated synovial inflammation and cartilage erosion in collagen-induced arthritis (CIA) rats. In conclusion, our discoveries propose that ARL4C assumes a central role in the synovial inflammation, cartilage degradation, and bone erosion associated with RA by triggering the PI3K/AKT and MAPK signaling pathways within RA FLSs.ARL4C holds promise as a prospective target for the development of pharmaceutical agents targeting FLSs, with the aim of addressing RA.

Timely escalation to second-line therapies after failure of methotrexate in patients with early rheumatoid arthritis does not reduce the risk of becoming difficult-to-treat

BACKGROUND

To investigate the frequency of difficult-to-treat (D2T) rheumatoid arthritis (RA) in patients early escalated to biologic/targeted synthetic disease modifying anti-rheumatic drugs (b/tsDMARDs) after failure of treat-to-target with methotrexate (MTX).

METHODS

From a prospective cohort of early RA, all patients with their first access in the years 2005-2018, and eventually starting a b/tsDMARD before the end of 2022, were included and followed-up until April 2024. Study outcomes included drug survival on each consecutive b/tsDMARDs, development of D2T (according to the EULAR definition and subsequent modifications), and its predictors.

RESULTS

Of a total cohort of 722 early RA patients treated with initial MTX and followed-up for at least 3 years from diagnosis, 155 (21.5%) had started a b/tsDMARD after a median of 19 months. In more than 70% of the cases, RA was uncontrolled despite optimal doses of MTX of ≥ 15 mg/day. The retention rates of the first and the second b/tsDMARD were approximatively 70% after 1 year but dropped to 40% after 5 years. After a median (IQR) follow up of 72.6 (34.5-134.2) months, 45 patients (29%) fulfilled the EULAR D2T criteria. At multivariable analysis, higher number of swollen joints and worse pain scores were confirmed as predictors of D2T. Furthermore, in this early RA cohort, shorter disease duration at the start of treatment with b/tsDMARDs, together with negativity for autoantibodies, were also independent predictors of D2T.

CONCLUSIONS

Early implementation of treatment after failure of treat-to-target with MTX may not prevent the development of D2T in RA. Patients showing early refractoriness to conventional drugs and those lacking autoantibodies are at higher risk of multiple treatment failures.

Interleukin-35 protein inhibits osteoclastogenesis and attenuates collagen-induced arthritis in mice

Rheumatoid arthritis (RA) is a chronic autoimmune disease. Its pathological features include synovial inflammation, bone erosion, and joint structural damage. Our previous studies have shown that interleukin (IL)-35 is involved in the pathogenesis of bone loss in RA patients. In this study, we are further evaluating the efficacy of IL-35 on collagen-induced arthritis (CIA) in the mouse model. Male DBA/1J mice (n = 10) were initially immunized, 2 μg/mouse IL-35 was injected intraperitoneally every week for 3 weeks after the establishment of the CIA model. Clinical arthritis, histopathological analysis, and three-dimensional micro‑computed tomography (3D micro‑CT) were determined after the mice were anesthetized on the 42th day. In vitro, RANKL/M-CSF induced mouse preosteoclasts (RAW264.7 cells line) was subjected to antiarthritis mechanism study in the presence of IL-35. The results of clinical arthritis, histopathological analysis, and 3D micro‑CT, the expression of RANK/RANKL/OPG axis, inflammatory cytokines, and osteoclastogenesis-related makers demonstrated decreasing severity of synovitis and bone destruction in the ankle joints after IL-35 treatment. Furthermore, IL-35 attenuated inflammatory cytokine production and the expression of osteoclastogenesis-related makers in a mouse preosteoclasts cell line RAW264.7. The osteoclastogenesis-related makers were significantly reduced in IL-35 treated RAW264.7 cells line after blockage with the JAK/STAT1 signaling pathway. These results demonstrated that IL-35 protein could inhibits osteoclastogenesis and attenuates CIA in mice. We concluded that IL-35 can exhibit anti-osteoclastogenesis effects by reducing the expression of inflammatory cytokines and osteoclastogenesis-related makers, thus alleviating bone destruction in the ankle joint and could be a potential therapeutic target for RA.

Propionibacterium freudenreichii MJ2-derived extracellular vesicles inhibit RANKL-induced osteoclastogenesis and improve collagen-induced rheumatoid arthritis

Rheumatoid arthritis causes excessive bone loss by stimulating osteoclast differentiation. Extracellular vesicles are valuable disease markers, conveyors of distant cell-to-cell communication, and carriers for drug delivery. The aim of this study was to investigate the anti-osteoclastogenic effects of extracellular vesicles derived from dairy Propionibacterium freudenreichii MJ2 (PFEVs) and the improvement effect of PFEVs on collagen-induced arthritis (CIA) animal model. PFEVs were observed by scanning electron microscopy, transmission electron microscopy, nanoparticle tracking analysis, and LC-MS/MS. The inhibitory activity of PFEVs against receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclast differentiation was investigated in RAW 264.7 cells. PFEVs significantly decreased the expression levels of genes and proteins related to osteoclast differentiation. PFEVs decreased RANK-RANKL binding. In a CIA mouse model, PFEVs treatment significantly reduced arthritis scores and collagen-specific immunoglobulins. PFEVs treatment also reduced pro-inflammatory cytokines and increased anti-inflammatory cytokines. The anti-inflammatory effects were confirmed by H&E staining, and PFEVs treatment inhibited osteoclastogenesis in the CIA mouse model. In conclusion, PFEVs inhibited osteoclast differentiation by inhibiting RANK-RANKL signaling, thereby decreasing the expression of osteoclast differentiation-related genes. PFEVs also improved collagen-induced arthritis by inhibiting inflammation and osteoclastogenesis.

Walking pace is a protective factor for rheumatoid arthritis: a mendelian randomization study

Walking pace is a simple and functional form of exercise and a strong predictor of health, but little is known about its causal association with rheumatoid arthritis. This study aimed to investigate the causal effect of WP on the developing RA using Mendelian randomization analysis. The genetic variation associated with WP was selected as an instrumental variable from the latest genome-wide association studies. Summary-level data for the outcomes were obtained from the corresponding GWAS. The inverse-variance weighted method was used as the primary MR analysis. The results were further tested using a multivariable MR approach based on Bayesian model averaging. Confounders (BMI, SMK, HBP, TD) with close associations with RA were included in the analysis. An observational study with individual data from UK Biobank was performed to reinforce our findings. The MR results indicated the significant inverse associations of WP with the risk of RA (odds ratio (OR), 0.31; 95% confidence interval (CI), 0.15, 0.62; p = 1.05 × 10 -3). After adjusting for the risk factors, the associations for WP and RA did not change substantially. Observational study results demonstrated the same effect of WP on reducing the risk of RA. The Mendelian randomization analysis and observational study provide evidence suggesting that walking pace is a protective factor for rheumatoid arthritis. Given its simple measurement, walking pace may be a pragmatic target for interventions.

Minimally invasive interventional procedures for osteoarthritis and inflammatory arthritis: A systematic review and meta-analysis

OBJECTIVE

to summarize the evidence on the efficacy of minimally invasive interventional procedures such as radiofrequency ablation (RFA) and transcatheter arterial embolization (TAE) in patients with osteoarthritis or inflammatory arthritis.

METHODS

a literature search was conducted in PubMed and Web of Science databases. Both randomized controlled trials (RCTs) and non-randomized studies of interventions (NRSI) were included. The results were organized according to the treated anatomical site: knee, hip, foot and ankle, shoulder, hand and wrist, sacroiliac joints. Data about treatment efficacy were extracted. The main outcome was change in pain intensity using the 0-10 visual analog scale (VAS) from baseline to 1 month. Additional timepoints at 3, 6 and 12 months were assessed. Change in functional status was evaluated. Pooled estimates were calculated as the mean difference (MD) and 95 % confidence interval relative to baseline. The meta-analyses of RCTs and NRSI were conducted separately.

RESULTS

of the 4599 retrieved articles, 164 were included in the review and, considering all the established timepoints, 111 (38 RCTs and 73 NRSI) were selected for the meta-analysis. Only one article described patients with inflammatory arthritis. In the meta-analysis of RCTs, one month after the procedure, MD in VAS was -3.98 (-4.41 to -3.55; k = 21) for knee RFA, and -3.18 (-3.96 to -2.39; k = 8) for sacroiliac joints RFA. In the meta-analysis of NRSI, MD in VAS was -4.12 (-4.63 to -3.61; k = 23) for knee RFA, -3.84 (-4.77 to -2.92; k = 7) for knee TAE, -4.34 (-4.96 to -3.71; k = 2) for hip RFA, -3.83 (-4.52 to -3.15; k = 3) for shoulder RFA and -4.93 (-5.58 to -4.28; k = 14) for sacroiliac joints RFA. Significant decrease in pain intensity was found also at 3, 6 and 12 months. Additionally, functional status improved at all the assessed timepoints.

CONCLUSION

minimally invasive interventional procedures can improve pain and functional status of patients affected by OA or chronic sacroiliac pain of degenerative origin. Further research is warranted in the field of inflammatory rheumatic diseases.

FTO-mediated RNA m6A methylation regulates synovial aggression and inflammation in rheumatoid arthritis

Fibroblast-like synoviocytes (FLS) plays an important role in synovial inflammation and joint damage in rheumatoid arthritis (RA). As the most abundant mRNA modification, N6-methyladenosine (m6A) is involved in the development of various diseases; however, its role in RA remains to be defined. In this study, we reported the elevated expression of the m6A demethylase fat mass and obesity-associated protein (FTO) in FLS and synovium from RA patients. Functionally, FTO knockdown or treatment with FB23-2, an inhibitor of the mRNA m6A demethylase FTO, inhibited the migration, invasion and inflammatory response of RA FLS, however, FTO-overexpressed RA FLS exhibited increased migration, invasion and inflammatory response. We further demonstrated that FTO promoted ADAMTS15 mRNA stability in an m6A-IGF2BP1 dependent manner. Notably, the severity of arthritis was significantly reduced in CIA mice with FB23-2 administration or CIA rats with intra-articular injection of FTO shRNA. Our results illustrate the contribution of FTO-mediated m6A modification to joint damage and inflammation in RA and suggest that FTO might be a potential therapeutic target in RA.

Truth unveiled by time and the marbled definition of D2T-RA: retrospective analysis on the persistence of the difficult-to-treat status among refractory RA patients

BACKGROUND

The current EULAR definition of difficult-to-treat rheumatoid arthritis (D2T-RA) identifies patients with active disease refractory to multiple treatments at a single time point, without considering the persistence of this condition over time. The study aimed to assess difficult-to-treat rheumatoid arthritis (D2T-RA) over 12 months, considering persistence over time rather than a single time point, in a real-life cohort.

METHODS

In a single-center real-life cohort, demographic and clinic data were cross-sectionally collected for each patient at baseline and retrospectively over the previous 12 months bimonthly. For each timepoint, the prevalence of D2T-RA patients was calculated, and patients meeting the EULAR definition for at least 6 months were defined as persistent D2T-RA (pD2T-RA). Finally, the clinical characteristics associated with the time-based definition of pD2T-RA were analyzed.

RESULTS

Among 610 adult RA patients, 104 were refractory to ≥ 2 treatments. Initially, 41.3% met D2T-RA criteria, but only 27.9% fulfilled persistent D2T-RA (pD2T-RA) criteria over 6 months. The pD2T-RA group was associated with male gender, higher HAQ and Charlson Comorbidity Index scores, more failed treatments, and use of non-NSAID analgesics. Logistic regression linked pD2T-RA to higher SDAI and CRP values, and the use of glucocorticoids or analgesics. Chronic use of glucocorticoids was strongly associated with pD2T-RA.

CONCLUSIONS

The application of a temporal criterion allowed for the selection of a subgroup of pD2T-RA patients who differ from those who meet the definition of D2T-RA only episodically. Chronic use of glucocorticoids was the factor most strongly associated with pD2T-RA status.

Identification of novel biomarker hsa_circ_0003914 for rheumatoid arthritis from plasma exosomes

Rheumatoid arthritis (RA) is a complex autoimmune disease featuring invasive and infiltrative fibroblast-like synoviocytes (FLS) that lead to joint damage. While current RA pathological mechanisms remain incompletely defined, exosomes have been implicated as having the potential to drive disease progression due to their ability to deliver different types of biomolecules to tissues effected by RA. One potentially disease exacerbating molecule type found in exosomes are Circular RNAs (circRNAs), which are highly stable and have been previously implicated in RA pathogenesis. Here, we examine hsa_circ_0003914, a circRNA found in exosomes located in blood plasma, for a role in RA. Plasma exosomes were isolated and injected into collagen-induced arthritis (CIA) mice, followed by functional experiments to analyze the influence of exosomes on FLS formation. Sequencing revealed the presence of hsa_circ_0003914 in exosomes, so we examined its association with clinical markers in RA. Finally, the role for hsa_circ_0003914 in RA was directly confirmed through in vivo and in vitro experiments. We found that plasma exosomes isolated from RA patients could aggravate the disease of CIA mice, compared to exosomes isolated from healthy control patients. Hsa_circ_0003914 was highly enriched in the exosomes of RA patients. Mechanistically, Hsa_circ_0003914 promoted abnormal cell proliferation, migration, invasion and stimulated the secretion of inflammatory cytokines in FLSs through targeting NF-κB/p65 signaling pathway. Interestingly, knockdown of hsa_circ_0003914 rescued disease phenotypes in CIA mice. Taken together, these data implicate hsa_circ_0003914 as a potential therapeutic target for the prevention and management of RA.

Subsequent biologic and targeted synthetic disease modifying anti rheumatic drugs after fulfilling difficult-to-treat rheumatoid arthritis criteria: a survival analysis

OBJECTIVES

To evaluate the survival of different biologic or targeted-synthetic disease-modifying antirheumatic drugs (b/tsDMARD) administered after fulfilling difficult-to-treat rheumatoid arthritis (D2TRA) criteria, and to assess factors related to treatment discontinuation.

METHODS

Retrospective study including D2TRA patients. Drug retention of the b/tsDMARD administered after fulfilling D2TRA was assessed by Kaplan-Meier plots and the log-rank test. Cox hazard models were used to identify factors affecting treatment discontinuation.

RESULTS

Of the 122 patients included, 75 maintained active treatment (61.5%) with a subsequent line after D2T compared to 47 (38.5%) who discontinued and required more successive lines of b/tsDMARDs. The median survival of the treatments was 78.3(7.6) months and the treatment after D2T with the better rate of survival was rituximab, followed by JAKi and IL6Ri, while worse survival rates were associated with abatacept and TNFi. Significant differences were noted among b/tsDMARDs (log-rank p < 0.01) and to evaluate these differences, a Cox regression was performed, taking each b/tsDMARD as a reference and comparing it with the others. DAS28 values 6-months after initiation of treatment were higher in those patients who discontinued treatment [4.4(1.2) vs 3.5(1.3), p = 0.01]. The multivariate cox regression model revealed that treatment choice after D2T [HR = 1.26(95%CI 1.06-1.05)] and lower DAS28 values at 6 months [HR = 1.49(95%CI 1.16-1.52)] were independent risk factors associated with treatment discontinuation.

CONCLUSIONS

Once patients met the D2TRA criteria, the subsequent line of b/tsDMARDs with the best survival rates were rituximab, JAKi and IL6Ri. Moreover, DAS28 at 6-months of treatment after D2T was an independent risk factor for drug discontinuation. Key Points • Rituximab, IL6Ri and JAKi have better retention rates in patients after fulfilling D2TRA criteria • Clinical disease activity in the first six months after fulfillment of D2TRA criteria is an independent risk factor of subsequent treatment survival.

Predictive factors and treatment outcomes associated with difficult-to-treat rheumatoid arthritis conditions: the ANSWER cohort study

OBJECTIVES

To investigate the predictive factors for difficult-to-treat rheumatoid arthritis (D2T RA) and assess the efficacy of biologic DMARDs (bDMARDs) and Janus kinase inhibitors (JAKi).

METHODS

Retrospective analysis was conducted on data from the ANSWER cohort comprising 3623 RA patients treated with bDMARDs or JAKi in Japan. Multivariate Cox proportional hazards modelling was used to analyse the hazard ratios (HRs) for treatment retention.

RESULTS

Of the 3623 RA patients, 450 (12.4%) met the first two criteria of the EULAR D2T RA definition (defined as D2T RA in this study). Factors contributing to D2T RA included age over 75 (compared with those under 65, hazard ratio [HR] = 0.46; 95% CI: 0.31, 0.69), higher rheumatoid factor (RF) titres (HR = 1.005; 95% CI: 1.00, 1.01), higher clinical disease activity index (HR = 1.02; 95% CI: 1.01, 1.03), lower methotrexate dosage (HR = 0.97; 95% CI: 0.95, 0.99), and comorbidities like hypertension (HR = 1.53; 95% CI: 1.2, 1.95) and diabetes (HR = 1.37; 95% CI: 1.09, 1.73). Anti-IL-6 receptor antibodies (aIL-6R, HR = 0.53; 95% CI: 0.37, 0.75) and JAKi (HR = 0.64; 95% CI: 0.46, 0.90) were associated with fewer discontinuations due to ineffectiveness compared with TNF inhibitors. Oral glucocorticoid usage (HR = 1.65; 95% CI: 1.11, 2.47) was linked to increased discontinuation due to toxic adverse events.

CONCLUSION

Younger onset, higher RF titres, and comorbidities predicted D2T RA development. For managing D2T RA, aIL-6R and JAKi exhibited superior drug retention.

New Therapeutic Strategies for the Inflammatory Rheumatoid Arthritis Disease: Emphasizing Mesenchymal Stem Cells and Associated exo-miRNA or exo-lncRNA

The most prevalent inflammatory arthritis and a leading contributor to disability is rheumatoid arthritis (RA). Although it may not have arrived in Europe until the 17th century, it was present in early Native American communities several thousand years ago. Exosomes released by mesenchymal stem cells (MSCs) are highly immunomodulatory due to the origin of the cell. As a cell-free therapy, MSCs-exosomes are less toxic and elicit a weakened immune response than cell-based therapies. Exosomal noncoding RNAs (ncRNAs) are closely associated with a number of biological and functional facets of human health, especially microRNAs (miRNAs) and long noncoding RNAs (lncRNAs). Various exo-miRNAs and lncRNAs such as HAND2-AS1, miR-150-5p, miRNA-124a, and miR-320a lodged with MSC could be appropriate therapeutic ways for RA treatment. These MSC-derived exosomes affect RA disorders via different molecular pathways such as NFK-β, MAPK, and Wnt. The purpose of this review is to review the research that has been conducted since 2020 so far in the field of RA disease treatment with MSC-loaded exo-miRNAs and exo-lncRNAs.

Biologics or Janus Kinase Inhibitors in Rheumatoid Arthritis Patients Who are Insufficient Responders to Conventional Anti-Rheumatic Drugs

Rheumatoid arthritis (RA) is a chronic immune-mediated inflammatory disease which can induce progressive disability if not properly treated early. Over the last 20 years, the improvement of knowledge on the pathogenesis of the disease has made available several drugs targeting key elements of the pathogenetic process, which now represent the preferred treatment option after the failure of first-line therapy with conventional drugs such as methotrexate (MTX). To this category of targeted drugs belong anti-cytokine or cell-targeted biological agents and more recently also Janus kinase inhibitors (JAKis). In the absence to date of specific biomarkers to guide the therapeutic choice in the context of true precision medicine, the choice of the first targeted drug after MTX failure is guided by treatment cost (especially after the marketing of biosimilar products) and by the clinical characteristics of the patient (age, sex, comorbidities and compliance) and the disease (presence or absence of autoantibodies and systemic or extra-articular manifestations), which may influence the efficacy and safety profile of the available products. This viewpoint focuses on the decision-making process underlying the personalized approach to RA therapy and will analyse the evidence in the literature supporting the choice of individual products and in particular the differential choice between biological drugs and JAKis.

The immunomodulatory of interleukin-33 in rheumatoid arthritis: A systematic review

Rheumatoid arthritis (RA) is a systemic chronic autoimmune disease that primarily affects the joints and surrounding soft tissues, characterized by chronic inflammation and proliferation of the synovium. Various immune cells are involved in the pathophysiology of RA. The complex interplay of factors such as chronic inflammation, genetic susceptibility, dysregulation of serum antibody levels, among others, contribute to the complexity of the disease mechanism, disease activity, and treatment of RA. Recently, the cytokine storm leading to increased disease activity in RA has gained significant attention. Interleukin-33 (IL-33), a member of the IL-1 family, plays a crucial role in inflammation and immune regulation. ST2 (suppression of tumorigenicity 2 receptor), the receptor for IL-33, is widely expressed on the surface of various immune cells. When IL-33 binds to its receptor ST2, it activates downstream signaling pathways to exert immunoregulatory effects. In RA, IL-33 regulates the progression of the disease by modulating immune cells such as circulating monocytes, tissue-resident macrophages, synovial fibroblasts, mast cells, dendritic cells, neutrophils, T cells, B cells, endothelial cells, and others. We have summarized and analyzed these findings to elucidate the pathways through which IL-33 regulates RA. Furthermore, IL-33 has been detected in the synovium, serum, and synovial fluid of RA patients. Due to inconsistent research results, we conducted a meta-analysis on the association between serum IL-33, synovial fluid IL-33, and the risk of developing RA in patients. The pooled SMD was 1.29 (95% CI: 1.15-1.44), indicating that IL-33 promotes the onset and pathophysiological progression of RA. Therefore, IL-33 may serve as a biomarker for predicting the risk of developing RA and treatment outcomes. As existing drugs for RA still cannot address drug resistance in some patients, new therapeutic approaches are needed to alleviate the significant burden on RA patients and healthcare systems. In light of this, we analyzed the potential of targeting the IL-33/ST2-related signaling pathway to modulate immune cells associated with RA and alleviate inflammation. We also reviewed IL-33 and RA susceptibility-related single nucleotide polymorphisms, suggesting potential involvement of IL-33 and macrophage-related drug-resistant genes in RA resistance therapy. Our review elucidates the role of IL-33 in the pathophysiology of RA, offering new insights for the treatment of RA.

Human embryonic stem cell-derived mesenchymal stromal cells suppress inflammation in mouse models of rheumatoid arthritis and lung fibrosis by regulating T-cell function

BACKGROUND AIMS

Rheumatoid arthritis (RA) is characterized by an overactive immune system, with limited treatment options beyond immunosuppressive drugs or biological response modifiers. Human embryonic stem cell-derived mesenchymal stromal cells (hESC-MSCs) represent a novel alternative, possessing diverse immunomodulatory effects. In this study, we aimed to elucidate the therapeutic effects and underlying mechanisms of hESC-MSCs in treating RA.

METHODS

MSC-like cells were differentiated from hESC (hESC-MSCs) and cultured in vitro. Cell proliferation was assessed using Cell Counting Kit-8 assay and Ki-67 staining. Flow cytometry was used to analyze cell surface markers, T-cell proliferation and immune cell infiltration. The collagen-induced arthritis (CIA) mouse model and bleomycin-induced model of lung fibrosis (BLE) were established and treated with hESC-MSCs intravenously for in vivo assessment. Pathological analyses, reverse transcription-quantitative polymerase chain reaction and Western blotting were conducted to evaluate the efficacy of hESC-MSCs treatment.

RESULTS

Intravenous transplantation of hESC-MSCs effectively reduced inflammation in CIA mice in this study. Furthermore, hESC-MSC administration enhanced regulatory T cell infiltration and activation. Additional findings suggest that hESC-MSCs may reduce lung fibrosis in BLE mouse models, indicating their potential to mitigate complications associated with RA progression. In vitro experiments revealed a significant inhibition of T-cell activation and proliferation during co-culture with hESC-MSCs. In addition, hESC-MSCs demonstrated enhanced proliferative capacity compared with traditional primary MSCs.

CONCLUSIONS

Transplantation of hESC-MSCs represents a promising therapeutic strategy for RA, potentially regulating T-cell proliferation and differentiation.

The problem of residual pain in the assessment of rheumatoid arthritis activity

Residual pain is a major unmet medical need observed in patients suffering from rheumatoid arthritis (RA), which decreases their quality of life, even after achieving remission or low disease activity. The article has two aims: 1) to present mechanisms involved in the pathophysiology of residual pain, both inflammatory and non-inflammatory, i.e. neuropathic and nociplastic pain, as well as secondary pain syndromes, i.e. osteoarthritis and fibromyalgia, which can contribute to residual pain; 2) to show the limitations of current disease activity measures recommended by European Alliance of Associations for Rheumatology (EULAR) and American College of Rheumatology (ACR), which raise the need for a separate assessment of pain, and examples of methods that could be used by medical professionals to assess the pain and make a differential diagnosis. In conclusion, establishing a valid method to assess pain is essential to identify the pathomechanism of residual pain and to create treatments tailored specifically to individual RA patients.

Evaluation of genetic polymorphisms in TNF‑α‑308G/A rs1800629 associated with susceptibility and severity of rheumatoid arthritis: A systematic review and meta‑analysis

To investigate the association of gene polymorphisms of TNF-α-308G/A rs1800629 with the susceptibility and severity of rheumatoid arthritis (RA), literature from PubMed, EMBASE, Web of Science and CNKI databases was searched. Two authors screened the literature independently, extracted data and evaluated the risk of bias of the included studies. According to the inclusion and exclusion criteria, five genetic models were established: The allelic model (A vs. G), dominant model (GA + AA vs. GG), recessive model (AA vs. GG + GA), co-dominant model (AA vs. GG) and super-dominant model (GG + AA vs. GA). Stata 17.0 software was used for the meta-analysis. A total of 34 eligible studies with 12,611 subjects were included, including 6,030 cases in the RA group and 6,581 controls. Meta-analysis calculations revealed that the genetic polymorphisms of TNF-α-308G/A rs1800629 were not significantly associated with susceptibility to RA, with an odds ratio and 95% confidence interval (CI) for each genetic model [A vs. G: 0.937 (0.762-1.152); GA + AA vs. GG: 0.918 (0.733-1.148); AA vs. GG + GA: 1.131 (0.709-1.802); AA vs. GG: 1.097 (0.664-1.813); and GG + AA vs. GA: 1.108 (0.894-1.373)]. For the association between TNF-α-308G/A rs1800629 gene polymorphisms and the severity of RA, the results of subgroup analysis calculations showed that TNF-α-308G/A rs1800629 gene polymorphisms were associated with the severity of RA in European populations, with the gene model and 95% CI [GA + AA vs. GG: 0.503 (0.297-0.853); and GG + AA vs. GA: 2.268 (1.434-3.590)]. When assessing the confidence in the positive results of the present study through the false-positive report probability, the positive results were observed to be reliable. No significant association was observed between genetic polymorphisms in TNF-α-308G/A rs1800629 and susceptibility to RA. However, a significant association exists with the severity of RA in European populations.

Itaconate reduces proliferation and migration of fibroblast-like synoviocytes and ameliorates arthritis models

Fibroblast-like synoviocytes (FLS) play critical roles in rheumatoid arthritis (RA). Itaconate (ITA), an endogenous metabolite derived from the tricarboxylic acid (TCA) cycle, has attracted attention because of its anti-inflammatory, antiviral, and antimicrobial effects. This study evaluated the effect of ITA on FLS and its potential to treat RA. ITA significantly decreased FLS proliferation and migration in vitro, as well as mitochondrial oxidative phosphorylation and glycolysis measured by an extracellular flux analyzer. ITA accumulates metabolites including succinate and citrate in the TCA cycle. In rats with type II collagen-induced arthritis (CIA), intra-articular injection of ITA reduced arthritis and bone erosion. Irg1-deficient mice lacking the ability to produce ITA had more severe arthritis than control mice in the collagen antibody-induced arthritis. ITA ameliorated CIA by inhibiting FLS proliferation and migration. Thus, ITA may be a novel therapeutic agent for RA.

Elevated Serum Levels of YKL-40, YKL-39, and SI-CLP in Patients with Treatment Failure to DMARDs in Patients with Rheumatoid Arthritis

Around 30-60% of patients with rheumatoid arthritis (RA) present treatment failure to conventional synthetic disease-modifying antirheumatic drugs (csDMARDs). Chitinase-like proteins (CLPs) (YKL-40, YKL-39, SI-CLP) might play a role, as they are associated with the inflammatory process. This study aimed to evaluate CLP utility as a biomarker in the treatment failure of csDMARDs. A case-control study included 175 RA patients classified into two groups based on therapeutic response according to DAS28-ESR: responders (DAS28 < 3.2); non-responders (DAS28 ≥ 3.2). CLP serum levels were determined by ELISA. Multivariable logistic regression and receiver operating characteristic (ROC) curves were used to evaluate CLPs' utility as biomarkers of treatment failure. Non-responders presented higher levels of YKL-40, YKL-39, and SI-CLP compared with responders (all: p < 0.001). YKL-40 correlated positively with YKL-39 (rho = 0.39, p < 0.001) and SI-CLP (rho = 0.23, p = 0.011) and YKL-39 with SI-CLP (rho = 0.34, p < 0.001). The addition of CLPs to the regression models improves diagnostic accuracy (AUC 0.918) compared to models including only clinical classical variables (AUC 0.806) p < 0.001. Non-responders were positive for all CLPs in 35.86%. Conclusions: CLPs could be considered as a useful biomarker to assess treatment failure, due to their association with clinical variables and improvement to the performance of regression models.

Five-year follow-up of patients with difficult-to-treat rheumatoid arthritis

OBJECTIVES

To elucidate the long-term outcomes of patients with difficult-to-treat rheumatoid arthritis (D2T RA).

METHODS

We collected data on the clinical course of patients who had been identified as D2T RA in 2018 until 2023. We stratified the patients according to outcomes at the last visit: resolved D2T RA, persistent D2T RA, and mortality. We compared their clinical characteristics and investigated the predictive factors for the resolution of D2T RA or mortality. Furthermore, we investigated the impact of the causes of D2T RA identified in 2018, multidrug resistance, comorbidities, and socioeconomic factors on outcomes in 2023.

RESULTS

Of 173 patients identified as D2T RA in 2018, 150 were included in the analysis. Among them, D2T RA was resolved in 67 (45%), 75 (50%) remained as D2T RA, and 8 (5%) died. Patients with resolved D2T RA were significantly younger at the latest visit (p= 0.02), had a higher proportion of treatment changes during five years (p= 0.002), and had a higher proportion of interleukin-6 receptor inhibitors use in 2023 (p= 0.04) than those in patients with persistent D2T RA or those who died. D2T RA resolved in 38% of patients with multidrug resistance, mainly with treatment changes. Rheumatic disease comorbidity index and glucocorticoid dose escalation were independent risk factors for mortality (odds ratio [OR], 3.50; p= 0.02 and OR, 31.9; p= 0.002, respectively).

CONCLUSION

Further modifications in RA treatment are useful for resolving D2T RA. Multiple comorbidities and glucocorticoid use are associated with mortality.

Protective effects of polydatin against bone and joint disorders: the in vitro and in vivo evidence so far

Polydatin is an active polyphenol displaying multifaceted benefits. Recently, growing studies have noticed its potential therapeutic effects on bone and joint disorders (BJDs). Therefore, this article reviews recent in vivo and in vitro progress on the protective role of polydatin against BJDs. An insight into the underlying mechanisms is also presented. It was found that polydatin could promote osteogenesis in vitro, and symptom improvements have been disclosed with animal models of osteoporosis, osteosarcoma, osteoarthritis and rheumatic arthritis. These beneficial effects obtained in laboratory could be mainly attributed to the bone metabolism-regulating, anti-inflammatory, antioxidative, apoptosis-regulating and autophagy-regulating functions of polydatin. However, studies on human subjects with BJDs that can lead to early identification of the clinical efficacy and adverse effects of polydatin have not been reported yet. Accordingly, this review serves as a starting point for pursuing clinical trials. Additionally, future emphasis should also be devoted to the low bioavailability and prompt metabolism nature of polydatin. In summary, well-designed clinical trials of polydatin in patients with BJD are in demand, and its pharmacokinetic nature must be taken into account.

Regulation of rheumatoid arthritis microenvironment via a self-healing injectable hydrogel for improved inflammation elimination and bone repair

The rheumatoid arthritis (RA) microenvironment is often followed by a vicious circle of high inflammation, endogenous gas levels imbalance, and poor treatment. To break the circle, we develop a dual-gas-mediated injectable hydrogel for modulating the immune microenvironment of RA and simultaneously releasing therapeutic drugs. The hydrogel (DNRS gel) could be broken down on-demand by consuming excessive nitric oxide (NO) and releasing therapeutic hydrogen sulfide (H2S), resulting in endogenous gas restoration, inflammation alleviation, and macrophage polarization to M2 type. Additionally, the hydrogel could suppress osteoclastogenesis and enhance osteogenesis. Furthermore, the intra-articularly injected hydrogel with methotrexate (MTX/DNRS gel) significantly alleviated inflammation and clinical symptoms and promoted the repair of bone erosion in the collagen-induced arthritis rat model. As a result, in vivo results demonstrated that MTX/DNRS gel restored the microenvironment and improved the therapeutic effect of MTX. This study provides a novel understanding of developing versatile smart delivery platforms for RA treatment.

Reasons for multiple biologic and targeted synthetic DMARD switching and characteristics of treatment refractory rheumatoid arthritis

OBJECTIVE

Switching biologic and targeted synthetic DMARD (b/tsDMARD) medications occurs commonly in RA patients, however data are limited on the reasons for these changes. The objective of the study was to identify and categorize reasons for b/tsDMARD switching and investigate characteristics associated with treatment refractory RA.

METHODS

In a multi-hospital RA electronic health record (EHR) cohort, we identified RA patients prescribed ≥1 b/tsDMARD between 2001 and 2017. Consistent with the EULAR "difficult to treat" (D2T) RA definition, we further identified patients who discontinued ≥2 b/tsDMARDs with different mechanisms of action. We performed manual chart review to determine reasons for medication discontinuation. We defined "treatment refractory" RA as not achieving low disease activity (<3 tender or swollen joints on <7.5 mg of daily prednisone equivalent) despite treatment with two different b/tsDMARD mechanisms of action. We compared demographic, lifestyle, and clinical factors between treatment refractory RA and b/tsDMARD initiators not meeting D2T criteria.

RESULTS

We identified 6040 RA patients prescribed ≥1 b/tsDMARD including 404 meeting D2T criteria. The most common reasons for medication discontinuation were inadequate response (43.3 %), loss of efficacy (25.8 %), and non-allergic adverse events (13.7 %). Of patients with D2T RA, 15 % had treatment refractory RA. Treatment refractory RA patients were younger at b/tsDMARD initiation (mean 47.2 vs. 55.2 years, p < 0.001), more commonly female (91.8% vs. 76.1 %, p = 0.006), and ever smokers (68.9% vs. 49.9 %, p = 0.005). No RA clinical factors differentiated treatment refractory RA patients from b/tsDMARD initiators.

CONCLUSIONS

In a large EHR-based RA cohort, the most common reasons for b/tsDMARD switching were inadequate response, loss of efficacy, and nonallergic adverse events (e.g. infections, leukopenia, psoriasis). Clinical RA factors were insufficient for differentiating b/tsDMARD responders from nonresponders.

Polymorphic Analysis of Genes PADI4 (rs2240340, rs1748033) and HLA-DRB1 (rs2395175) in Arthritis Patients in Pakistani Population

Genes are an important factor for the initiation of any disease. Many genes are associated with rheumatoid arthritis (RA) other than environmental factors. The main objective of the study was to evaluate the association of genes PADI4 (peptidylarginine deiminases 14) (rs2240340, rs1748033) and Human leukocyte antigen class II histocompatibility, D-related beta chain (HLA-DRB1) (rs2395175) polymorphisms in RA patients from Punjab, Pakistan. Blood samples of RA patients were collected from different hospitals of Sargodha. DNA was extracted, followed by PCR. Polymorphic analysis was performed in 300 rheumatoid arthritis patients and 300 healthy controls on PADI4 (rs2240340, rs1748033) and HLA-DRB1 (rs2395175). In PADI4 gene, both homozygous mutant genotype (TT) and heterozygous (CT) of SNP rs2240340 showed significant association by increasing the risk of RA up to two fold (OR 2.55; 95% CI 1.57-4.15; p = 0.0002). In case of rs1748033 polymorphism, homozygous mutant genotype (TT) showed significant association with RA by increasing the risk of disease up to three fold (OR 3.46; 95% CI 1.97-6.07; p = 0.0001), while heterozygous genotype (CT) of the same SNP showed significant association with RA by playing a protective role (OR 0.57; 95% CI 0.36-0.91; p = 0.0197). In HLA-DRB1 gene, homozygous mutant genotype (GG) of SNP rs2395175 showed no significant association with RA, while heterozygous genotype (AG) of the same SNP showed significant association with RA by playing a protective role (OR 0.44; 95% CI 0.27-0.71; p = 0.0009). Highly significance association of genes PADI4 (rs2240340, rs1748033) and HLA-DRB1 (rs2395175) polymorphisms with RA was observed in Pakistani population.

Modulation of plasmacytoid dendritic cells response in inflammation and autoimmunity

The discovery of toll-like receptors (TLRs) and the subsequent recognition that endogenous nucleic acids (NAs) could serve as TLR ligands have led to essential insights into mechanisms of healthy immune responses as well as pathogenic mechanisms relevant to systemic autoimmune and inflammatory diseases. In systemic lupus erythematosus, systemic sclerosis, and rheumatoid arthritis, NA-containing immune complexes serve as TLR ligands, with distinct implications depending on the additional immune stimuli available. Plasmacytoid dendritic cells (pDCs), the robust producers of type I interferon (IFN-I), are providing critical insights relevant to TLR-mediated healthy immune responses and tissue repair, as well as generation of inflammation, autoimmunity and fibrosis, processes central to the pathogenesis of many autoimmune diseases. In this review, we describe recent data characterizing the role of platelets and NA-binding chemokines in modulation of TLR signaling in pDCs, as well as implications for how the IFN-I products of pDCs contribute to the generation of inflammation and wound healing responses by monocyte/macrophages. Chemokine modulators of TLR-mediated B cell tolerance mechanisms and interactions between TLR signaling and metabolic pathways are also considered. The modulators of TLR signaling and their contribution to the pathogenesis of systemic autoimmune diseases suggest new opportunities for identification of novel therapeutic targets.

Nanoparticle-Mediated Multiple Modulation of Bone Microenvironment To Tackle Osteoarthritis

Development of nanomedicines that can collaboratively scavenge reactive oxygen species (ROS) and inhibit inflammatory cytokines, along with osteogenesis promotion, is essential for efficient osteoarthritis (OA) treatment. Herein, we report the design of a ROS-responsive nanomedicine formulation based on fibronectin (FN)-coated polymer nanoparticles (NPs) loaded with azabisdimethylphoaphonate-terminated phosphorus dendrimers (G4-TBP). The constructed G4-TBP NPs-FN with a size of 268 nm are stable under physiological conditions, can be specifically taken up by macrophages through the FN-mediated targeting, and can be dissociated in the oxidative inflammatory microenvironment. The G4-TBP NPs-FN loaded with G4-TBP dendrimer having intrinsic anti-inflammatory property and FN having both anti-inflammatory and antioxidative properties display integrated functions of ROS scavenging, hypoxia attenuation, and macrophage M2 polarization, thus protecting macrophages from apoptosis and creating designed bone immune microenvironment for stem cell osteogenic differentiation. These characteristics of the G4-TBP NPs-FN lead to their effective treatment of an OA model in vivo to reduce pathological changes of joints including synovitis inhibition and cartilage matrix degradation and simultaneously promote osteogenic differentiation for bone repair. The developed nanomedicine formulation combining the advantages of both bioactive phosphorus dendrimers and FN to treat OA may be developed for immunomodulatory therapy of different inflammatory diseases.