From patients with arthralgia, pre-RA and recently diagnosed RA: what is the current status of understanding RA pathogenesis?

Enhancing the effectiveness of immunotherapy in rheumatoid arthritis by delaying immunosenescence triggered by fibroblast-like synoviocytes

Rheumatoid arthritis (RA) is a prevalent autoimmune disorder primarily targeting the diarthrodial joints. During the progression of RA, fibroblast-like synoviocytes (FLSs) exhibit tumor-like behavior, including increased proliferation, inflammation mediation, and aggressive phenotypes, leading to bone erosion. Additionally, T cells in RA acquire pro-inflammatory characteristics, exacerbating the inflammatory environment in affected joints and associated tissues. Notably, senescent T cells contribute to inflammation, further accelerating the disease process. Metabolic changes in rheumatoid FLSs not only maintain their tumor-like properties but also trigger inflammatory cascades, particularly affecting T lymphocytes. This review examines the molecular alterations in RA FLSs in the context of systemic immune aging, with a focus on thymic insufficiency-associated T cell senescence, and explores potential therapeutic avenues.

Unveiling the Anti-Angiogenic Potential of Small-Molecule (Kinase) Inhibitors for Application in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by inflammation leading to joint damage and systemic complications. Angiogenesis promotes inflammation and contributes to RA progression. This study evaluated potential anti-angiogenic effects of several compounds including small-molecule kinase inhibitors, such as sunitinib (pan-kinase inhibitor), tofacitinib (JAK-inhibitor), NIKi (NF-κB-inducing kinase inhibitor), and the integrin-targeting peptide fluciclatide, using a scratch assay and 3D spheroid-based models of angiogenesis. For all drugs tested in the low micromolar range (1-25 μM), sunitinib (as positive anti-angiogenetic control) showed marked inhibition of endothelial cell (EC) migration and sprouting, effectively reducing both scratch closure and sprout formation. Tofacitinib exhibited marginal effectiveness in the scratch assay, but performed better in the 3D models (55% inhibition), whereas NIKi showed around 50% anti-angiogenic effects in both models. Fluciclatide changed EC morphology rather than migration, and only when stimulated with synovial fluid in spheroid model did it show inhibitory effects (at ≥2.5 µM), with none below this dosage. These results highlight the potential of NIKi and tofacitinib for angiogenesis inhibition and of fluciclatide for safe diagnostic targeting of microdose in RA, as well as the need for advanced screening models that mimic RA's complex inflammatory pro-angiogenic environment.

Role of TLR4 activation and signaling in bone remodeling, and afferent sprouting in serum transfer arthritis

BACKGROUND

In the murine K/BxN serum transfer rheumatoid arthritis (RA) model, tactile allodynia persists after resolution of inflammation in male and partially in female wild type (WT) mice, which is absent in Toll-like receptor (TLR)4 deficient animals. We assessed the role of TLR4 on allodynia, bone remodeling and afferent sprouting in this model of arthritis.

METHODS

K/BxN sera were injected into male and female mice with conditional or stable TLR4 deletion and controls. Paw swelling was scored and allodynia assessed by von Frey filaments. At day 28, synovial neural fibers were visualized with confocal microscopy and bone density assayed with microCT. Microglial activity and TLR4 dimerization in spinal cords were examined by immunofluorescence and flow cytometry.

RESULTS

In the synovium, K/BxN injected WT male and female mice showed robust increases in calcitonin gene related-peptide (CGRP+), tyrosine hydroxylase (TH)+ and GAP43+ nerve fibers. Trabecular bone density by microCT was significantly decreased in K/BxN WT female but not in WT male mice. The number of osteoclasts increased in both sexes of WT mice, but not in Tlr4-/- K/BxN mice. We used conditional strains with Cre drivers for monocytes/osteoclasts (lysozyme M), microglia (Tmem119 and Cx3CR1), astrocytes (GFAP) and sensory neurons (advillin) for Tlr4f/f disruption. All strains developed similar arthritis scores after K/BxN serum injection with the exception being the Tlr4Tmem119 mice which showed a reduction. Both sexes of Tlr4Lyz2, Tlr4Tmem119 and Tlr4Cx3cr1 mice displayed a partial reversal of the chronic pain phenotype but not in Tlr4Avil, and Tlr4Gfap mice. WT K/BxN male mice showed increases in spinal Iba1, but not GFAP, compared to Tlr4-/- male mice. To determine whether spinal TLR4 was indeed activated in the K/BxN mice, flow cytometry of lumbar spinal cords of WT K/BxN male mice was performed and revealed that TLR4 in microglia cells (CD11b+ /TMEM119+) demonstrated dimerization (e.g. activation) and a characteristic increase in lipid rafts.

CONCLUSION

These results demonstrated a complex chronic allodynia phenotype associated with TLR4 in microglia and monocytic cell lineages, and a parallel spinal TLR4 activation. However, TLR4 is dispensable for the development of peripheral nerve sprouting in this model.

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

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

A novel treatment modality for rheumatoid arthritis: Inflammation-targeted multifunctional metal-organic frameworks with synergistic phototherapy and chemotherapy

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease with complex pathogenesis. Single chemotherapy struggles to eliminate the disease permanently and reduce the pain owing to drug resistance and inadequate delivery to target cells. This study developed hyaluronic acid (HA)-modified and methotrexate (MTX)-load metal-organic frameworks (denoted as FT-HA-MTX NPs), combining photothermal therapy (PTT), photodynamic therapy (PDT), and chemotherapy to inhibit the progression of RA. In vitro experiments proved that the obtained NPs exhibited good biocompatibility and commendable photothermal conversion efficiency of 36.3 %. Additionally, they promoted ∙OH and O2 production via the Fenton reaction, which dramatically alleviated hypoxia and enhanced ROS generation, and induced substantial mortality in activated RAW 264.7 cells, with cell viability of 31.72 %. Cellular uptake and in vivo imaging confirmed that the modification of HA enabled the NPs to specifically target activated macrophage, ensured prolonged retention of NPs in inflamed synovial tissues, and reduced systemic toxicity. In vivo, after FT-HA-MTX NPs treatment with laser irradiation, the levels of TNF-α and IL-1β in the synovial tissue were reduced by approximately 50 % compared to those in the inflamed synovium, demonstrating a significant enhancement in the anti-inflammatory effect (p < 0.001). In conclusion, FT-HA-MTX NPs are promising inflammation-targeted multifunctional nanoparticles that combine PTT, PDT, and chemotherapy, thereby significantly inhibiting the progression of RA while reducing systemic toxicity.

METTL3 knockdown suppresses RA-FLS activation through m6A-YTHDC2-mediated regulation of AMIGO2

The dysregulation of N6-methyladenosine (m6A) on mRNAs is involved in the pathogenesis of rheumatoid arthritis (RA). Methyltransferase-like 3 (METTL3), serving as a central m6A methyltransferase, is highly expressed in macrophages, synovial tissues and RA fibroblast-like synoviocytes (RA-FLS) of RA patients. However, METTL3-mediated m6A modification on target mRNAs and the molecular mechanisms involved in RA-FLS remain poorly defined. Our research demonstrated that METTL3 knockdown decreased the proliferation, migratory and invasive abilities of RA-FLS. Notably, we identified the adhesion molecule with Ig like domain 2 (AMIGO2) as a probable downstream target of both METTL3 and YTH Domain Containing 2 (YTHDC2) in RA-FLS. We revealed that AMIGO2 augmented the activation of RA-FLS and can potentially reverse the phenotypic effects induced by the knockdown of either METTL3 or YTHDC2. Mechanistically, METTL3 knockdown decreased m6A modification in the 5'-untranslated region (5'UTR) of AMIGO2 mRNA, which diminished its interaction with YTHDC2 in RA-FLS. Our findings unveiled that silencing of METTL3 inhibited the proliferation and aggressive behaviors of RA-FLS by downregulating AMIGO2 expression in an m6A-YTHDC2 dependent mechanism, thereby underscoring the pivotal role of the METTL3-m6A-YTHDC2-AMIGO2 axis in modulating RA-FLS phenotypes.

Integrative non-pharmacological care for individuals at risk of rheumatoid arthritis

There is increasing knowledge in the recognition of individuals at risk for progression to rheumatoid arthritis (RA) before the clinical manifestation of the disease. This prodromal phase preceding the manifestation of RA may represent a "window of opportunity" for preventive interventions that may transform the clinical approach to this disease. However, limited evidence exists in support of effective interventions to delay the onset or even halt the manifestation of RA. Given the multifactorial nature of RA development and disease progression, the latest guidelines for established RA stress the use of integrative interventions and multidisciplinary care strategies, combining pharmacologic treatment with non-pharmacological approaches. Accordingly, individuals at risk of RA could be offered an integrative, multifactorial intervention approach. Current data point toward pharmacological intervention reverting the subclinical inflammation and delay in the disease onset. In addition, targeting life style modifiable factors (smoking cessation, dental health, physical activity, and diet) may presumably improve RA prognosis in individuals at risk, mainly by changes in epigenetics, autoantibodies, cytokines profiles, and microbiome. Nonetheless, the benefits of multidisciplinary interventions to halt the manifestation of RA in at-risk individuals remain unknown. As there is a growing knowledge of possible pharmacological intervention in the preclinical phase, this narrative review aims to provide a comprehensive overview of non-pharmacological treatments in individuals at risk of RA. Considering the mechanisms preceding the clinical manifestation of RA we explored all aspects that would be worth modifying and that would represent an integrative non-pharmacological care for individuals at risk of RA.

Role of artesunate in autoimmune diseases and signaling pathways

Artesunate (ART) is a derivative of artemisinin. Compared with artemisinin, ART has excellent water solubility, high stability and oral bioavailability. In this review, the application of ART in classic autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus and ulcerative colitis is summarized. ART exhibited similar or even better efficacy than other highly effective immunosuppressive agents, such as methotrexate and cyclophosphamide. In addition, ART exerts its pharmacological effects mainly by inhibiting the production of inflammatory factors, reactive oxygen species, autoantibodies and the migration of cells to reduce damage to tissues or organs. Moreover, ART widely affected the NF-κB, PI3K/Akt, JAK/STAT and MAPK pathways to exert pharmacological effects.

Macrophage Polarization and the Regulation of Bone Immunity in Bone Homeostasis

Bone homeostasis is a dynamic equilibrium state of bone formation and absorption, ensuring skeletal development and repair. Bone immunity encompasses all aspects of the intersection between the skeletal and immune systems, including various signaling pathways, cytokines, and the crosstalk between immune cells and bone cells under both homeostatic and pathological conditions. Therefore, as key cell types in bone immunity, macrophages can polarize into classical pro-inflammatory M1 macrophages and alternative anti-inflammatory M2 macrophages under the influence of the body environment, participating in the regulation of bone metabolism and playing various roles in bone homeostasis. M1 macrophages can not only act as precursors of osteoclasts (OCs), differentiate into mature OCs, but also secrete pro-inflammatory cytokines to promote bone resorption; while M2 macrophages secrete osteogenic factors, stimulating the differentiation and mineralization of osteoblast precursors and mesenchymal stem cells (MSCs), and subsequently increase bone formation. Once the polarization of macrophages is imbalanced, the resulting immune dysregulation will cause inflammatory stimulation, and release a large amount of inflammatory factors affecting bone metabolism, leading to pathological conditions such as osteoporosis (OP), rheumatoid arthritis (RA), and steroid-induced femoral head necrosis (SANFH). In this review, we introduce the signaling pathways and related factors of macrophage polarization, as well as their relationships with immune factors, OB, OC, and MSC. We also discuss the roles of macrophage polarization and bone immunity in various diseases of bone homeostasis imbalance, as well as the factors regulating them, which may help to develop new methods for treating bone metabolic disorders.

Distinct innate and adaptive immunity phenotypic profile at the circulating single-cell level in Psoriatic Arthritis

Mass cytometry was employed to investigate 47 circulating leukocyte subsets in patients with active psoriatic arthritis (PsA, n = 16) compared to healthy controls (n = 13), seropositive (RF and/or anti-CCP, n = 12) and seronegative (n = 9) RA patients. Comparing PsA to controls, different cell frequencies were found in both innate and adaptive immunity cell subsets, as well as in cells bridging innate and adaptive immunity. In some T-cell subsets increased costimulatory molecules' expression in PsA, was also noted..No changes were observed in patients who remained disease-active after 3 months of treatment, in contrast to those who achieved remission/low-disease activity. Comparing PsA to seropositive RA, elevated frequencies of naïve and activated CD8⁺ T-cells, B-cells, MAIT/iNKT and ILCs were found, while the opposite was the case for terminal effector, senescent, and Th2-like-cells. Strikingly, the composition of the leukocyte pool in PsA was comparable to seronegative RA, providing evidence for the pathogenetic similarities between these two entities.

The effect of JuanBiQiangGu granules in combination with methotrexate on joint inflammation in rheumatoid arthritis: a randomized controlled trial

Background: Rheumatoid arthritis (RA) joint inflammation severely affects joint function and quality of life in patients and leads to joint deformities and limb disability. The non-steroidal anti-inflammatory drugs used in the treatment of RA do not fully control the progression of joint inflammation and bone destruction and have notable adverse reactions. Traditional Chinese medicine formula JuanBiQiangGu Granules (JBQG) are commonly used for the treatment of RA inflammation and delay of bone destruction, but has not been evaluated through high-quality clinical studies. There is a pressing need for well-designed, randomized, parallel, controlled clinical studies to evaluate the exact effect of JBQG on RA joint inflammation and improvement of patient quality of life. Methods: This is a randomized, parallel, controlled clinical study in which 144 patients with rheumatoid arthritis who met the inclusion criteria were randomly assigned to 2 groups in a 1:1 ratio. The JBQG group received methotrexate 7.5 mg qw and JBQG granules 8 mg tid, while the MTX group received methotrexate 7.5 mg qw. The endpoint was 12 weeks after treatment. Relevant indices at baseline, 4 weeks, 8 weeks, and 12 weeks after treatment were observed and recorded, and DAS28-ESR, HAQ-DI, and Sharp scores were recorded for each patient. Blood samples were collected to test for CRP, ESR, TNF-α, IL-1β, IL-6, IL-17, and INF-γ, and adverse reactions and liver and kidney function (AST, ALT, Cr, BUN) were recorded for safety assessment. After 12 weeks of treatment, the effect of JBQG granules on disease activity, improvement in bone damage, and patient quality of life scores and safety in RA patients were evaluated. Results: A total of 144 subjects completed treatment (71 in the JBQG group and 73 in the MTX group) and were included in the analysis. At baseline, there were no significant differences between the groups in terms of the observed indicators (p > 0.05). After treatment, 76.06% of patients in the JBQG group had DAS28-ESR levels below or equal to Low, including 45.07% in Remission and 5.63% in High, compared to 53.1% in the MTX group below or equal to Low, 12.33% in Remission, and 17.81% in High. CRP was significantly reduced (8.54 ± 5.87 vs. 11.86 ± 7.92, p < 0.05, p = 0.005), ESR was significantly reduced (15.1 ± 6.11 vs. 21.96 ± 9.19, p < 0.0001), TNF-α was significantly reduced (1.44 ± 0.83 vs. 1.85 ± 1.07, p < 0.05, p = 0.011), IL-17 was significantly reduced (0.53 ± 0.33 vs. 0.71 ± 0.38, p < 0.05, p = 0.004), and INF-γ was significantly reduced (3.2 ± 1.51 vs. 3.89 ± 1.77, p < 0.05, p = 0.014). The median (IQR) OPG in the JBQG group was 2.54 (2.21-3.01), significantly higher than in the MTX group 2.06 (1.81-2.32), p < 0.0001), and the median (IQR) β-CTX in the JBQG group was 0.4 (0.32-0.43), significantly lower than in the MTX group 0.55 (0.47-0.67), p < 0.0001). The median (IQR) VSA scores were 2 (1-3), a decrease from 3 (2-4) in the MTX group (p < 0.0001). The median (IQR) Sharp scores were 1 (1-2), a decrease from 2 (1-2) in the MTX group, but the difference was not statistically significant (p > 0.05, p = 0.28). The median (IQR) HAQ-DI scores were 11 (8-16), significantly lower than in the MTX group 26 (16-30) (p < 0.0001). The median (IQR) AST in the JBQG group was 16 (12-20), with a significant difference compared to the MTX group 19 (13-25) (p < 0.01, p = 0.004); the median (IQR) ALT in the JBQG group was 14 (10-18), with a significant difference compared to the MTX group 16 (11-22.5) (p < 0.05, p = 0.015). There were no statistically significant differences in Cr or BUN (p > 0.05). Conclusion: JuanBiQiangGu Granules can be used to treat patients with rheumatoid arthritis, alleviate joint inflammation, reduce the incidence of adverse reactions to methotrexate, and has good safety. Clinical Trial Registration: http://www.chinadrugtrials.org.cn/index.html; identifier: ChiCTR2100046373.

Tenderness and radiographic progression in rheumatoid arthritis and psoriatic arthritis

OBJECTIVE

The aim of this study was to assess the predictive value of tenderness in the absence of swelling with consideration of other potential risk factors for subsequent radiographic progression in rheumatoid arthritis (RA) and psoriatic arthritis (PsA).

METHODS

Clinical and sonographic (grey scale and power Doppler (PD)) examination of 22 joints of the hand were performed in patients with RA and PsA. The impact of tenderness on progression after 2 years was analysed in non-swollen joints for RA and PsA separately with multilevel mixed logistic regression analysis.

RESULTS

We included 1207 joints in 55 patients with RA and 352 joints in 18 patients with PsA. In RA, tenderness was associated with radiographic progression after 2 years (model 2: OR 1.85 (95% CI 1.01 to 3.27), p=0.047), although the association of PD (OR 2.92 (95% CI 1.71 to 5.00), p<0.001) and erosions (OR 4.74 (95% CI 2.44 to 9.23), p<0.001) with subsequent structural damage was stronger. In PsA, we found a positive but not significant association between tenderness and radiographic progression (OR 1.72 (95% CI 0.71 to 4.17), p=0.23). In contrast, similarly to RA, erosions (OR 4.62 (95% CI 1.29 to 16.54), p=0.019) and PD (OR 3.30 (95% CI 1.13 to 9.53), p=0.029) had a marked effect on subsequent structural damage.

CONCLUSION

Our findings imply that tenderness in non-swollen joints in RA is associated with subsequent damage. In both diseases, additional risk factors, such as sonographic signs for synovitis and baseline radiographic damage are associated with radiographic progression.

Signaling pathways in rheumatoid arthritis: implications for targeted therapy

Rheumatoid arthritis (RA) is an incurable systemic autoimmune disease. Disease progression leads to joint deformity and associated loss of function, which significantly impacts the quality of life for sufferers and adds to losses in the labor force. In the past few decades, RA has attracted increased attention from researchers, the abnormal signaling pathways in RA are a very important research field in the diagnosis and treatment of RA, which provides important evidence for understanding this complex disease and developing novel RA-linked intervention targets. The current review intends to provide a comprehensive overview of RA, including a general introduction to the disease, historical events, epidemiology, risk factors, and pathological process, highlight the primary research progress of the disease and various signaling pathways and molecular mechanisms, including genetic factors, epigenetic factors, summarize the most recent developments in identifying novel signaling pathways in RA and new inhibitors for treating RA. therapeutic interventions including approved drugs, clinical drugs, pre-clinical drugs, and cutting-edge therapeutic technologies. These developments will hopefully drive progress in new strategically targeted therapies and hope to provide novel ideas for RA treatment options in the future.

Increased circulating sclerostin levels in rheumatoid arthritis patients: an updated meta-analysis

BACKGROUND

Sclerostin, a regulator of bone metabolism and vascular calcification involved in regulating the Wnt/β-catenin signaling pathway, has been shown to be involved in the pathogenesis of rheumatoid arthritis (RA). However, current results regarding the circulating sclerostin level of RA patients are debatable. This study aimed to evaluate the circulating level of sclerostin in RA patients and briefly summarize its role.

METHOD

PubMed, EMBASE, and the Cochrane Library databases were systematically searched till May 27, 2021, for eligible articles. Useful data from all qualified papers were systematically extracted and analyzed using Stata 12.0 software (Stata Corp LP, College Station, TX, USA).

RESULTS

Overall, 13 qualifying studies including 1030 cases and 561 normal controls were analyzed in this updated meta-analysis. Forest plot of this meta-analysis showed that RA patients had higher circulating sclerostin levels (P < 0.001, standardized mean difference [SMD] = 0.916, 95% CI: 0.235-1.597) compared to normal controls. Subgroup analyses implied that age, region, and assay method were associated with sclerostin level in RA patients.

CONCLUSION

RA patients have higher circulating sclerostin levels, and these was influenced by age, region, and assay method.

LncRNA RNA XIST binding to GATA1 contributes to rheumatoid arthritis through its effects on proliferation of synovial fibroblasts and angiogenesis via regulation of CCN6

This study explored the role of the long non-coding RNA (lncRNA) XIST (X-inactive specific transcript) as a driver of RA pathogenesis, with a particular focus on the ability of this lncRNA to interact with GATA1 and CCN6. The GSE83147and GSE181614 datasets were downloaded for analysis. XIST and CCN6 expression were assessed in synovial fibroblasts (SFs) and in both normal cartilage samples and those from RA patients, with the relationship between XIST and CCN6 additionally being examined. XIST and CCN6 were respectively knocked down or overexpressed in SFs to establish their regulatory roles in these cells in the context of RA. Further studies of the regulatory interplay between XIST, GATA1, and CCN6 were then performed through RNA immunoprecipitation, RNA pull-down, gain-of-function, loss-of-function, and luciferase reporter assays. In addition, RA model rats were established and used to measure the production of TNF-α, IL-6, and IL-8 and to subject tissues from these animals to histopathological examination. RA patient synovial tissues and SFs exhibited XIST and CCN6 upregulation. The knockdown of XIST suppressed SF migratory, proliferative, invasive, and angiogenic activity, while CCN6 knockdown partially reversed the ability of XIST to influence these phenotypic outcomes in vitro and in vivo. XIST bound to GATA1 within SFs, thus promoting enhanced CCN6 transcription. Knocking down XIST alleviated RA-related pathological damage, synovial injury, and inflammatory response induction in rats. The binding of XIST to GATA1 leads to CCN6 upregulation, driving RA pathogenesis by altering SF proliferation and angiogenic activity, suggesting that this pathway may represent a viable target for therapeutic intervention.

EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2022 update

OBJECTIVES

To provide an update of the EULAR rheumatoid arthritis (RA) management recommendations addressing the most recent developments in the field.

METHODS

An international task force was formed and solicited three systematic literature research activities on safety and efficacy of disease-modifying antirheumatic drugs (DMARDs) and glucocorticoids (GCs). The new evidence was discussed in light of the last update from 2019. A predefined voting process was applied to each overarching principle and recommendation. Levels of evidence and strengths of recommendation were assigned to and participants finally voted on the level of agreement with each item.

RESULTS

The task force agreed on 5 overarching principles and 11 recommendations concerning use of conventional synthetic (cs) DMARDs (methotrexate (MTX), leflunomide, sulfasalazine); GCs; biological (b) DMARDs (tumour necrosis factor inhibitors (adalimumab, certolizumab pegol, etanercept, golimumab, infliximab including biosimilars), abatacept, rituximab, tocilizumab, sarilumab and targeted synthetic (ts) DMARDs, namely the Janus kinase inhibitors tofacitinib, baricitinib, filgotinib, upadacitinib. Guidance on monotherapy, combination therapy, treatment strategies (treat-to-target) and tapering in sustained clinical remission is provided. Safety aspects, including risk of major cardiovascular events (MACEs) and malignancies, costs and sequencing of b/tsDMARDs were all considered. Initially, MTX plus GCs is recommended and on insufficient response to this therapy within 3-6 months, treatment should be based on stratification according to risk factors; With poor prognostic factors (presence of autoantibodies, high disease activity, early erosions or failure of two csDMARDs), any bDMARD should be added to the csDMARD; after careful consideration of risks of MACEs, malignancies and/or thromboembolic events tsDMARDs may also be considered in this phase. If the first bDMARD (or tsDMARD) fails, any other bDMARD (from another or the same class) or tsDMARD (considering risks) is recommended. With sustained remission, DMARDs may be tapered but should not be stopped. Levels of evidence and levels of agreement were high for most recommendations.

CONCLUSIONS

These updated EULAR recommendations provide consensus on RA management including safety, effectiveness and cost.

Oral Microbiome in Pre-Rheumatoid Arthritis: The Role of Aggregatibacter Actinomycetemcomitans in Bacterial Composition

Rheumatoid arthritis (RA) is a chronic autoimmune disease that symmetrically affects the joints, eventually leading to cartilage and tissue destruction. While there are multiple etiologies for RA, from environmental to genetic risk factors, periodontal disease (PD) may contribute to the acceleration of RA symptoms in pre-rheumatoid arthritis (pre-RA) and RA patients. While PD is caused by multiple oral bacteria, this review explains the role of Aggregatibacter actinomycetemcomitans (Aa) in the pathogenesis of pre-RA and RA based on 13 primary articles. This paper focuses on the Aa virulence factor leukotoxin A (LtxA) because it has been reported to cause cellular destruction and inflammation in the oral cavity that can accelerate the development of RA. Individuals who are classified as pre-RA may benefit from periodontal screening to further reduce their risk of developing advanced RA. Additionally, they may benefit from earlier pharmacological therapy for RA using disease-modifying anti-rheumatic drugs (DMARD) and antibacterial treatment.

Disease mechanisms in preclinical rheumatoid arthritis: A narrative review

In the last decades, the concept of preclinical rheumatoid arthritis (RA) has become established. In fact, the discovery that disease mechanisms start years before the onset of clinical RA has been one of the major recent insights in the understanding of RA pathogenesis. In accordance with the complex nature of the disease, preclinical events extend over several sequential phases. In a genetically predisposed host, environmental factors will further increase susceptibility for incident RA. In the initial steps of preclinical disease, immune disturbance mechanisms take place outside the joint compartment, namely in mucosal surfaces, such as the lung, gums or gut. Herein, the persistent immunologic response to altered antigens will lead to breach of tolerance and trigger autoimmunity. In a second phase, the immune response matures and is amplified at a systemic level, with epitope spreading and widening of the autoantibody repertoire. Finally, the synovial and bone compartment are targeted by specific autoantibodies against modified antigens, initiating a local inflammatory response that will eventually culminate in clinically evident synovitis. In this review, we discuss the elaborate disease mechanisms in place during preclinical RA, providing a broad perspective in the light of current evidence.

Giant Intraosseous Cyst-Like Lesions of the Metacarpal Bones in Rheumatoid Arthritis

The purpose of this study was to illustrate the clinical and imaging properties of giant intraosseous cyst-like lesions (GICLs) of the metacarpal bones extending beyond the central diaphysis in rheumatoid arthritis (RA) patients on magnetic resonance (MR) images. A keyword search was conducted to extract GICLs of the metacarpal bones out of MR reports in RA patients. There were nine GICLs extending from the subchondral bone region beyond the central diaphysis of the metacarpal bones on MR images in eight subjects with RA (seven females, one male). The age range was from 60 to 87 years with a median age of 65.5 years. The average disease duration was 13.1 years. As for the disease activity, one was low, six were moderate and one was high. None of the nine lesions were visible on radiography. The Steinbrocker stage distribution was as follows: I (n = 3), II (n = 2), and III (n = 3). Intraosseous cyst-like lesion of the metacarpal bones on MR images is a relatively rare manifestation in patients with long-standing RA. Although the lesion seems to be derived from subcortical bone break, it is not necessarily erosive in nature.

Circulating anti-citrullinated protein antibodies containing secretory component are prognostic for arthritis onset in at-risk patients

Autoantibodies related to rheumatoid arthritis (RA), such as anti‐citrullinated protein antibodies (ACPA), are often detectable in the preclinical period years before arthritis onset. However, events triggering arthritis development remain incompletely known. We aimed to determine whether ACPA isotype levels are prognostic for arthritis development in patients presenting with immunoglobulin (Ig)G ACPA and musculoskeletal pain. Study participants (n = 82) had musculoskeletal pain of any sort and duration and a positive IgG ACPA test. None of the patients had arthritis upon clinical examination at baseline, but during follow‐up (mean = 6 years), 48% developed at least one arthritic joint. IgG, IgA, IgM and secretory component (SC)‐containing ACPA was measured in longitudinally collected serum samples. Cox regression analysis was performed to test the prognostic value of baseline antibody levels and changes over time. All analysed ACPA isotype levels were associated with arthritis development in univariable Cox regression analysis. In multivariable analysis, baseline SC ACPA levels were independently prognostic for arthritis development in multivariable analysis [hazard ratio (HR) = 1·006, 95% confidence interval (CI) = 1·001–1·010, P = 0·012]. There were no significant changes in ACPA isotype levels over time, and no significant association between changes over time and arthritis development. In this prospective longitudinal study, baseline serum SC ACPA levels, but neither IgG, IgA nor IgM ACPA are prognostic for future arthritis development. Repeated measurement of ACPA isotypes do not bring additional prognostic value. The results reinforce a mucosal connection in RA development and encourage further exploration of the mechanisms underlying secretory ACPA formation as a trigger for arthritis development.

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.

Fibroblast-like synoviocytes in rheumatoid arthritis: Surface markers and phenotypes

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease that mainly affects synovial joints. During the course of RA, the synovium transforms into hyperplastic invasive tissue, leading to cartilage and bone destruction. Fibroblast-like synoviocytes (FLS) in the synovial lining develop aggressive phenotypes and produce pathogenic mediators that lead to the occurrence and progression of disease, playing a major role in RA pathophysiology. Therefore, research on FLS has become the main focus within the RA field. With technical advances and the development of multi-omics comprehensive analysis approaches, it has become possible to identify different FLS subsets via high-throughput sequencing and investigate differences between FLS phenotypes, allowing for the detailed study of RA pathogenesis. This review summarizes recent works on FLS subtypes and the surface marker proteins identified for different subtypes, providing a theoretical basis and reference for future studies on FLS in RA. The current work also addresses the clinical potential of FLS surface markers in RA based on related research from other fields.

THH Relieves CIA Inflammation by Reducing Inflammatory-related Cytokines

Tripterygium hypoglaucum hutch (THH) is a plant of the genus tripterygium, which is also known as colquhounia, Gelsemiun elegan, and so on. It is mainly distributed in Yunnan, Guizhou, and Sichuan regions and other places in China. To study the immune mechanism of THH on related inflammatory cytokines in collagen II-induced arthritis (CIA) mice, healthy male C57BL/6 mice were used to model CIA mice. Mice received THH 420 mg/kg/day or the same amount of normal saline (NS) by gavage for 20 days. The thickness of the ankle joint in mice was observed, and the arthritis index was calculated. Related inflammatory cytokines were detected by real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. The results showed that after treatment with THH, the CIA mice had less swelling and destruction of the joints as well as decreased foot size and arthritis index. The mRNA and protein levels of TNF-α, IFN-γ, and IL-17A were lower in the THH-treated group than in the NS group (P < 0.05). In summary, THH has great significance in the treatment of CIA mice, including reduced related inflammatory cytokines expression level in both joint tissue and serum. The mechanism of THH in the treatment of CIA may be through the inhibition of the NF-kB-STAT3-IL-17 pathway, which also requires further experimental investigation.

[Danggui Niantong decoction induces apoptosis by activating Fas/caspase-8 pathway in rheumatoid arthritis fibroblast-like synoviocytes]

OBJECTIVE

To explore the effect of Danggui Niantong decoction (DGNTD) on cell apoptosis and TNF receptor super family 6 (Fas)/caspase-8 pathway in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS).

METHODS

FLS isolated from the synovial tissue of RA patients were cultured and identified using immunofluorescence staining. The cells were treated with 10% blank serum (blank control group), 10% sera containing low, moderate or high doses of DGNTD, or 20 μmol/mL KR-33493 (a Fas inhibitor) combined with 10% serum containing high-dose DGNTD. MTT assay was used to detect the proliferation of the cells after the treatments. Apoptosis of the cells was detected at 48 h in each group using Hoechst 33342 staining and flow cytometry with annexin V-FITC/PI staining. The mRNA and protein expressions of Fas, FADD, caspase-8 and caspase-3 in the cells at 48 h were detected using qPCR and Western blotting.

RESULTS

Immunofluorescence staining identified the cultured cells as FLS. Treatment with DGNTD-containing sera significantly inhibited the proliferation of FLS, and the inhibitory effects were enhanced as the dose and intervention time increased (P < 0.05). Hoechst 33342 staining and flow cytometry showed that the sera containing different doses of DGNTD significantly promoted apoptosis of FLS (P < 0.05). The expression levels of Fas, FADD, caspase-8, and caspase-3 at both mRNA and protein levels were significantly increased in the cells after treatment with different doses of DGNTD-containing sera (P < 0.05). The application of KR-33493 obviously reversed the effects of DGNTD on the FLS (P < 0.05).

CONCLUSIONS

DGNTD can induce apoptosis of the FLS by activating Fas/caspase-8 signaling pathway.

The Anti-Inflammatory Mediator, Vasoactive Intestinal Peptide, Modulates the Differentiation and Function of Th Subsets in Rheumatoid Arthritis

Genetic background, epigenetic modifications, and environmental factors trigger autoimmune response in rheumatoid arthritis (RA). Several pathogenic infections have been related to the onset of RA and may cause an inadequate immunological tolerance towards critical self-antigens leading to chronic joint inflammation and an imbalance between different T helper (Th) subsets. Vasoactive intestinal peptide (VIP) is a mediator that modulates all the stages comprised between the arrival of pathogens and Th cell differentiation in RA through its known anti-inflammatory and immunomodulatory actions. This “neuroimmunopeptide” modulates the pathogenic activity of diverse cell subpopulations involved in RA as lymphocytes, fibroblast-like synoviocytes (FLS), or macrophages. In addition, VIP decreases the expression of pattern recognition receptor (PRR) such as toll-like receptors (TLRs) in FLS from RA patients. These receptors act as sensors of pathogen-associated molecular pattern (PAMP) and damage-associated molecular pattern (DAMP) connecting the innate and adaptive immune system. Moreover, VIP modulates the imbalance between Th subsets in RA, decreasing pathogenic Th1 and Th17 subsets and favoring Th2 or Treg profile during the differentiation/polarization of naïve or memory Th cells. Finally, VIP regulates the plasticity between theses subsets. In this review, we provide an overview of VIP effects on the aforementioned features of RA pathology.

Identification of key genes in rheumatoid arthritis and osteoarthritis based on bioinformatics analysis

Rheumatoid arthritis (RA) and osteoarthritis (OA) comprise the most common forms of arthritis. The aim of this study was to identify differentially expressed genes (DEGs) and associated biological processes between RA and OA using a bioinformatics approach to elucidate their potential pathogenesis.The gene expression profiles of the GSE55457 datasets, originally produced through use of the high-throughput Affymetrix Human Genome U133A Array, were downloaded from the Gene Expression Omnibus (GEO) database. The GSE55457 dataset contains information from 33 samples, including 10 normal control (NC) samples, 13 RA samples, and 10 OA samples. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed to identify functional categories and associated molecular and biochemical pathways, respectively, for the identified DEGs, and a protein-protein interaction (PPI) network of the DEGs was constructed using Cytoscape software.GO and KEGG results suggested that several biological pathways (ie, "immune response," "inflammation," and "osteoclast differentiation") are commonly involved in the development of both RA and OA, whereas several other pathways (eg, "MAPK signaling pathway," and "ECM-receptor interaction") presented significant differences between these disorders.This study provides further insights into the underlying pathogenesis of RA and OA, which may facilitate the diagnosis and treatment of these diseases.